*Updated January 2017*

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1 *Updated January 2017* COURSE DESCRIPTION This CE course will describe common laboratory tests and their use in the diagnosis and treatment of disease. The tests are listed by the section of the laboratory where the tests are performed. However, this may vary by facility. The disease states are listed by body system. These lists are not meant to be all-inclusive. *Valid for P.A.C.E. credit through 12/31/2018* * ASCLS P.A.C.E. is an approved continuing education agency by the California Department of Health Laboratory Field Services, Accrediting Agency #0001. *NCCT is approved as a provider of continuing education programs in the clinical laboratory sciences by the ASCLS P.A.C.E. Program, provider #122. Rev 4 March 2017 COPYRIGHT 2017 National Center for Competency Testing Reproduction or translation of any part of this work beyond that permitted by Sections 107 or 108 of the 1976 United States Copyright Act without the permission of the copyright owner is unlawful. No part of this work may be reproduced or used in any form or by any means-graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage and retrieval systems without written permission of the publisher 1

2 COURSE TITLE: Common Lab Tests and Their Uses Author: Lucia Johnson, MA Ed, MT(ASCP)SBB Vice President, Recertification NCCT Number of Clock Hours Credit: 2.0 Course # P.A.C.E. Approved: X Yes _ No OBJECTIVES Upon completion of this continuing education course, the healthcare professional should be able to: 1. Name common laboratory tests. 2. Describe the usefulness of common laboratory tests in the diagnosis of disease and the maintenance of health. 3. Correlate common laboratory tests with disorders and diseases. 4. Describe common diseases and disorders by body systems. Disclaimer The writers for NCCT continuing education courses attempt to provide factual information based on literature review and current professional practice. However, NCCT does not guarantee that the information contained in the continuing education courses is free from all errors and omissions. 2

3 INTRODUCTION Laboratory tests are an important but often underappreciated aspect of healthcare. Billions of dollars are spent annually on laboratory tests, and the results of these tests are essential for the diagnosis and treatment of illness and maintenance of health. Research indicates laboratory test results influence 60% 70% of medical treatment decisions but they account for about 3% of Medicare all Medicare Part B payments. This CE course describes common laboratory tests and their usefulness in diagnosis and treatment of disease. The tests are listed by the department of the laboratory where the tests are usually performed. However, this may vary by facility. The disease states are listed by body system. These lists are not meant to be all-inclusive. FREQUENTLY PERFORMED LABORATORY TESTS HEMATOLOGY TESTS The hematology department performs laboratory tests to identify diseases and disorders associated with the blood and blood-forming tissues. These tests predominately involve the identification of the type and quantity of cells found in the blood, bone marrow, and other parts of the body. Hematology tests assist the physician in diagnosing infections, leukemia, polycythemia, anemia, and other blood abnormalities. Most of the tests are performed on either a hematology analyzer or flow cytometer. A hematology analyzer measures, identifies, and counts cells in a blood specimen. These analyses are performed using electrical and optical techniques, including electrical impedance and laser light scatter. The cells analyzed include red blood cells, platelets, and five types of white blood cells - neutrophils, lymphocytes, monocytes, eosinophils, and basophils. The test performed on a hematology analyzer is a complete blood count (CBC) which has many components. The results of the test assist with the diagnosis of anemias, leukemias, infections, and more. The specimen for hematology analysis is almost always a blood specimen anticoagulated with EDTA (lavender closure evacuated tube). In some circumstances, body fluids may be tested using a hematology analyzer. A flow cytometer measures and analyzes several physical characteristics of cells such as their size, granularity, and the presence of surface antigens, as determined by laser light scatter and immunofluorescence. Flow cytometry can identify the presence of specific types of lymphocytes which can be used to determine types of lymphomas and immunosuppressive disease states. Specimens used for flow cytometry include bone marrow, peripheral blood, lymph nodes, and other tissues. The most commonly performed hematology tests are listed in the following table. 3

4 TESTS COMMONLY PERFORMED IN THE HEMATOLOGY DEPARTMENT Test Evaluates/ Measures Diagnostic Use Body fluid analysis The number and type of cells in body fluids such as synovial, cerebrospinal, peritoneal, pleural, and more Bone marrow evaluation CD4 counts (T helper cell) Erythrocyte sedimentation rate (ESR, sed rate) Fetal hemoglobin determination for fetomaternal hemorrhage Hemoglobin and hematocrit (H and H) Hemoglobinopathy evaluation/hemoglobin electrophoresis Immune Studies Panel (flow cytometry) Leukemia/Lymphoma Panels (flow cytometry) Mean corpuscular hemoglobin* (MCH) Mean corpuscular hemoglobin concentration* (MCHC) Mean corpuscular volume* (MCV) Peripheral blood smear evaluation (manual differential) Platelet count* (Plt) The quantity and types of cells present in the bone marrow An antigen found on T helper lymphocytes, a type of cell that assists in the immune reaction The rate at which red blood cells settle to the bottom of a tube in a set time period The amount of blood containing hemoglobin F (found in the fetus and newborn) present in mother s blood; test may be called Kleihauer-Betke test Determines the oxygen carrying capacity of red blood cells and the percentage of these cells in the blood; may be ordered separately Identifies the type and quantity of normal and abnormal hemoglobin types present in the blood Determines the number of CD3, CD4, and CD19 lymphocytes in bone marrow specimens Identifies and quantitates all types and subsets of lymphocytes Determines the average amount of hemoglobin in a population of red blood cells Determines the average weight of hemoglobin in a red blood cell population and compares it with the size of the cell Determines the average size of red blood cells A specimen of blood is placed on a glass slide, stained, and microscopically evaluated for a detailed evaluation of the appearance and shape of the red and white blood cells including the presence of intracellular inclusions such as parasites, yeast, hemoglobin crystals, and more Determines the number of platelets in the circulating blood Red blood cell count* Determines the number of red blood (RBC) cells in the circulating blood *part of a Complete Blood Count Useful in identifying the presence of infection, inflammation, and malignancies Diagnose and identify types of leukemia, anemias, myelodysplasia, and other blood disorders Decreased counts are seen in HIV infection, lymphomas, and other diseases of the immune system Nonspecific test used to assist in the diagnosis of various inflammatory disorders During pregnancy and at birth, fetal blood can enter the mother s blood, resulting in problems for both the baby (anemia from blood loss) and the mother (depending on the blood types of the mother and baby, the need for additional doses of Rh immune globulin to prevent the formation of anti-d antibodies) Decreased in anemia; increased in polycythemia Used to diagnose sickle cell anemia (hemoglobin S disease), thalassemia, and other hemoglobinopathies Used to monitor patients undergoing bone marrow transplants, stem cell transplants, or chemotherapy Used to diagnose leukemias, lymphomas, and other types of lymphocyte cancers One of the RBC indices; used with other RBC indices to assist in the diagnosis of types of anemias One of the RBC indices; used with other RBC indices to assist in the diagnosis of types of anemias One of the RBC indices; used with other RBC indices to assist in the diagnosis of types of anemias Must be performed with hematology analyzer flags certain automated results as abnormal, or when diseases such as malaria, histoplasmosis, and others are suspected Decreased numbers seen in bleeding/hemorrhage; increased numbers seen in thrombocytosis Decreased numbers seen in anemia; increased numbers seen in polycythemia 4

5 TESTS COMMONLY PERFORMED IN THE HEMATOLOGY DEPARTMENT Test Evaluates/ Measures Diagnostic Use Red cell distribution width* (RDW) Calculation of the differences in the size of the red blood cells types of anemias Reticulocyte count* (Retic) Sickle cell screen T cell/b cell panels (flow cytometry) White blood cell count* (WBC) White blood cell differential* (Diff) *part of a Complete Blood Count COAGULATION TESTS Reticulocytes are slightly immature red blood cells and their number identifies the ability of the bone marrow to increase the production of red blood cells when needed Detects the presence of hemoglobin S which is found in sickle cell disease and sickle cell trait Identifies the types, subsets, and quantities of T and B lymphocytes Determines the number of white blood cells in the circulating blood Counts the five types of white blood cells present in the circulating blood and reports them in percentages (%): neutrophils, lymphocytes, monocytes, eosinophils, and basophils One of the RBC indices; used with other RBC indices to assist in the diagnosis of Increased numbers are seen in bleeding or hemolysis; decreased numbers may indicate a problem with the production of red blood cells in the bone marrow A positive test must be followed up with tests to identify the amount and type of abnormal hemoglobins present to confirm a diagnosis of sickle cell disease Used to diagnose leukemias, lymphomas, immunosuppressive disorders, and other lymphocyte malignancies High numbers may indicate an infection; a low numbers may indicate a bone marrow problem or a problem with a type of medication Increased or decreased numbers or ratios of cell types can indicate the presence of infection, leukemia, or many other disorders and conditions The coagulation department of a laboratory evaluates the overall process of hemostasis (the stoppage of blood flow from an injured vessel). This includes the coagulation mechanism (via the intrinsic, extrinsic, and common pathways) and the mechanism that dissolves blood clots which is called fibrinolysis. At least 30 substances such as enzymes, coagulation factors, and cells are involved in these processes. The absence or malfunction of any one of the substances can result in serious coagulation problems. Platelet numbers and function, blood vessel integrity, coagulation factors, fibrinolysis, coagulation inhibitors, and anticoagulant therapy are evaluated in the coagulation section. Disease conditions such as hemophilia and disseminated intravascular coagulation are examples of diseases and disorders that are identified using results of tests performed in this section. Most coagulation tests are performed on plasma that has been collected in evacuated tubes containing sodium citrate as the anticoagulant (light blue closure). Coagulation analyzers generally measure the length of time it takes for the patient s plasma to form a clot after the addition of standardized quantities of coagulation factors. This is either a photo-optical system that detects the increase in turbidity (cloudiness) of the specimen as it begins to clot or an electromechanical method where moving parts are stopped by the formation of a clot. A table of the most commonly performed coagulation tests follows. 5

6 TESTS COMMONLY PERFORMED IN THE COAGULATION DEPARTMENT Test Evaluates/Measures Diagnostic Use Activated partial thromboplastin time (aptt or PTT) The intrinsic and common coagulation pathways Bleeding time (BT) Platelet function; mostly replaced by platelet function assays Monitors heparin therapy; detects deficiencies of factors IX, VIII, X, V, prothrombin, and fibrinogen Measures the ability of platelets to work with cells in the blood vessel walls to stop bleeding D-dimer Derivatives of fibrin Diagnostic for fibrinolysis which is seen in disseminated intravascular coagulation, pulmonary embolism, arterial/venous thrombosis, and more Factor assays The amount of coagulation factors in the plasma; examples include Factor VIII, Factor X Diagnose hemophilia A, hemophilia B, von Willebrand disease, and more Fibrinogen The amount of fibrinogen in plasma Abnormal results can indicate fibrinolysis, disseminated intravascular coagulation, hemorrhage, placental abruption International normalized ratio (INR) Platelet function Prothrombin time (PT) CHEMISTRY TESTS Method of standardizing the results of prothrombin time tests, regardless of the testing method; some labs report only the INR (and not the PT) Platelet function such as the ability of platelets to aggregate, adhere, and release; to stop bleeding, platelets must be present in sufficient numbers and be able to function properly; function test most frequently performed is platelet aggregation Evaluates the extrinsic and common coagulation pathways; results can be highly variable from lab to lab due to the inherent nature of the assay Monitors warfarin (Coumadin) therapy Identifies disorders of platelet functions such as immune thrombocytopenic purpura, posttransfusion purpura, neonatal alloimmune thrombocytopenia, drug-induced thrombocytopenia, thrombotic thrombocytopenic purpura, von Willebrand disease, Bernard-Soulier syndrome, and more Monitors warfarin (Coumadin) therapy; should always be accompanied by an INR value The chemistry department of the laboratory is often the largest and it performs the majority of laboratory tests. The chemistry laboratory tests for many organic and inorganic substances in blood including enzymes, proteins, lipids, hormones, minerals, tumor markers, and more. The chemistry section also performs tests for therapeutic drug monitoring and tests that detect drugs of abuse. Tests in chemistry are performed on blood, urine, and various body fluids. Almost all chemistry tests are performed on analyzers that utilize enzymatic, immunologic, spectrophotometric, or other biochemical methods to measure substances in blood and body fluids. Blood tests can be performed on serum (red, gold, or red/gray closure tubes) or plasma from tubes containing heparin as an anticoagulant (green closure tubes). Plasma is often the preferred specimen as it can be ready for testing more rapidly than nonanticoagulated specimens that must be allowed to clot for at least 30 minutes before centrifugation to obtain serum for testing. 6

7 Chemistry tests are often grouped together into panels of related tests to aid in the diagnosis of diseases and disorders. Examples of these include liver function panels, thyroid function panels, and renal function panels. Some panel tests look for the overall function of many organ systems such as a basic metabolic panel and a comprehensive metabolic panel. A table of the most commonly performed chemistry tests follows. TESTS COMMONLY PERFORMED IN THE CHEMISTRY DEPARTMENT Test Evaluates/ Measures Diagnostic Use Acid phosphatase Same as test Elevated levels indicate prostate cancer Alanine Same as test Elevated levels indicate liver disorders aminotransferase (ALT) Albumin Same as test Decreased levels indicate liver or kidney disorders or malnutrition Alcohol Same as test Elevated levels indicate intoxication Alkaline phosphatase (ALP) Same as test Elevated levels indicate bone or liver disorders Ammonia Same as test Elevated levels indicate severe liver disorders Amylase Same as test Elevated levels indicate pancreatic disorders Aspartate Same as test Elevated levels indicate recent myocardial aminotransferase (AST) Basic metabolic panel Beta-human chorionic gonadotropin (β-hcg) BUN, electrolytes, glucose, calcium, and creatinine Detects the presence (screening tests) or quantitates (confirmative tests) 7 infarction or liver disorders Evaluates the status of the patient s kidneys, glucose, and electrolyte and acid/base balance Positive screening test indicates a pregnancy that should be confirmed by a quantitative test Bilirubin Same as test Elevated levels indicate liver or hemolytic disorders Blood urea nitrogen Same as test Elevated levels indicate kidney disorders (BUN) B-Type natriuretic peptide (BNP) Same as test Used to help diagnose and grade the severity of congestive heart failure Calcitonin Same as test Elevated levels seen in thyroid cancer and other malignancies Calcium Same as test Abnormal values associated with bone, musculoskeletal, or endocrine disorders Cholesterol Same as test Elevated levels indicate risk for cardiovascular disease Comprehensive metabolic panel Includes all of the tests in a BMP + albumin, ALP, ALT, AST, bilirubin, and total protein Provides information on the patient s glucose level, kidney function, electrolyte balance, acid-base balance, and liver function Creatine kinase (CK) Same as test Elevated levels indicate myocardial infarction or other muscle damage Determines the extent of muscle or brain damage Creatine kinase (CK) Same as test Isoenzymes Creatinine Same as test Elevated levels indicate kidney disorders Creatinine clearance Same as test Urine and serum tests used to measure the glomerular filtration rate of the kidney Drug screen Electrolytes 5 panel = amphetamines, cocaine, marijuana, opiates, and phencyclidine; 9 panel includes all of those in 5 panel + barbiturates, benzodiazepines, methadone, and propoxyphene Includes sodium, potassium, chloride, and carbon dioxide Identifies the presence of common drugs of abuse Evaluates body fluid balance

8 TESTS COMMONLY PERFORMED IN THE CHEMISTRY DEPARTMENT Test Evaluates/ Measures Diagnostic Use Gamma glutamyl Same as test Elevated levels indicate early liver disorders transferase (GGT) Glucose, fasting Same as test Elevated levels indicate diabetes Glucose, post-prandial Glucose 2 hours after a meal Elevated levels indicate diabetes Glucose tolerance test (GTT) Glucose in specimens collected over a 3 hour time period following Detects diabetes or hypoglycemia Hemoglobin A1c (also called glycohemoglobin or glycosylated hemoglobin) High density lipoprotein (HDL) ingestion of a set amount of glucose Same as test Results reflects the average blood glucose level for the past two-three months Same as test Used with other lipid tests to assess cardiovascular disease risk Iron Same as test Decreased levels may indicate iron deficiency anemia Lactic dehydrogenase (LD) Same as test Elevated levels indicate myocardial infarction or lung or liver disorders Lead Same as test Elevated levels indicate lead poisoning Lipase Same as test Elevated levels indicate pancreatic disorders Lipid profile Total cholesterol, HDL, LDL, and triglycerides Identifies the patient s risk of coronary heart disease and stroke Lithium Same as test Measures levels of the antidepressant drug lithium Liver function panel Albumin, ALP, ALT, AST, bilirubin, Assesses the functions of the liver (hepatitic function panel) GGT, LD, total protein; may include prothrombin time (PT) Low Density Lipoprotein (LDL) Same as test Used with other lipid tests to assess cardiovascular disease risk Myoglobin Same as test Elevated in myocardial infarction and skeletal Peak/Trough Therapeutic Drug Monitoring (TDM) Certain antibiotics, antidepressants, cardiac drugs, bronchodilators, antiseizure drugs; examples include procainamide, gentamicin, valproic acid, theophylline, tacrolimus, methotrexate, lithium muscle injuries Assures maintenance of medications in therapeutic range for maximum benefit to patient, and to assure toxic levels of the medications are avoided Phosphorus Same as test Abnormal levels associated with skeletal or endocrine disorders Protein Same as test Decreased levels associated with liver or kidney disorders Renal function panel (kidney function panel) Triiodothyronine (T3 or free T3/FT3) Albumin, calcium, creatinine, BUN, electrolytes, glucose, and phosphorus Same as test Assesses kidney function Increased levels indicate hyperthyroidism; decreased levels indicate hypothyroidism Thyroid function panel T3, T4, TSH Assesses the function of the thyroid gland Thyroxine (T4 or free T4/FT4) Same as test Increased levels indicate hyperthyroidism; decreased levels indicate hypothyroidism Thyroid stimulating hormone (TSH) Same as test Increased in hypothyroidism, decreased in hyperthyroidism Total Protein (TP) Same as test Decreased levels indicate liver or kidney disorders 8

9 TESTS COMMONLY PERFORMED IN THE CHEMISTRY DEPARTMENT Test Evaluates/ Measures Diagnostic Use Tumor markers Examples include CA-125 (ovarian cancer), CEA (colorectal cancer, others), PSA (prostate cancer), CA 15-3 (breast cancer) Elevated in certain types of cancer and can be used to diagnose; can be used to monitor the effectiveness of surgery or treatment of the cancer Triglycerides Same as test Used with other lipid tests to assess cardiovascular disease risk Troponins I and T (ctni Same as test Elevated levels seen in myocardial infarction and ctnt) Uric Acid Same as test Elevated levels indicate kidney disorders or gout BLOOD BANK/TRANSFUSION SERVICES TESTS The blood bank department of the laboratory is where blood and blood components donated by volunteers at blood centers are stored and prepared for transfusion to patients. Transfusions of red blood cells, platelets, fresh frozen plasma, cryoprecipitate, and injections of Rh immune globulin and specially prepared coagulation factors are given as treatments for diseases, disorders, and blood loss from trauma or surgery. Blood samples from donors and patients must be carefully tested before red blood cell or fresh frozen plasma transfusions can be given to assure compatibility of the blood products. Incompatible blood transfusions can have serious consequences, up to and including death. Patient identification and specimen labeling procedures, laboratory testing procedures, and nursing procedures must be strictly followed to assure the correct patient receives the correct blood product. The specimen preferred for blood bank testing in plasma from EDTA-anticoagulated (lavender or pink closure) evacuated tubes. In most hospitals, blood bank testing is performed using manual methods based on the ability of red blood cell antigens to agglutinate in the presence of antibodies. Automated blood bank testing is available but it is mostly used by blood donor centers and very large medical center laboratories. The following table identifies the tests most commonly performed in the blood bank/transfusion service department. TESTS COMMONLY PERFORMED IN THE BLOOD BANK/TRANSFUSION SERVICES DEPARTMENT Test Evaluates/ Measures Diagnostic Use ABO and Rh type (blood type) Identifies the presence or absence of antigens in the ABO and Rh blood group ABO and Rh types of the donor and recipient must be compatible to assure a Antibody screen Antibody identification Direct antihuman globulin test (DAT or direct Coombs) systems Detects abnormal antibodies to red cell antigens in many blood group systems Identifies abnormal antibodies to red cell antigens in many blood group systems Detects antibodies attached to red blood cell antigens safe transfusion of blood products Determines if additional testing is required prior to transfusion of blood products Presence of abnormal antibodies may complicate the provision of compatible blood products, and result in delayed hemolytic transfusion reactions and hemolytic disease of the newborn Positive tests are seen in autoimmune diseases, hemolytic transfusion reactions, and hemolytic disease of the newborn 9

10 TESTS COMMONLY PERFORMED IN THE BLOOD BANK/TRANSFUSION SERVICES DEPARTMENT Test Evaluates/ Measures Diagnostic Use Indirect antihuman Same as antibody screen See antibody screen globulin test (indirect Coombs) Transfusion reaction workup Type and crossmatch Type and screen A panel of tests performed when a patient has a suspected transfusion reaction A panel of tests performed on a patient prior to transfusion of blood; includes ABO and Rh type, antibody screen, and compatibility tests A panel of tests performed on a patient when transfusion may occur in the near future; includes and ABO and Rh type and antibody screen IMMUNOLOGY/SEROLOGY/MOLECULAR DIAGNOSTICS TESTS Provides information on the type of reaction the patient had (if any) to the transfusion: acute hemolytic, delayed hemolytic, allergic, febrile, circulatory overload, anaphylactic, or transfusionrelated acute lung injury Performed prior to transfusion of to assure compatibility of blood products Determines the ease in which blood transfusions can be provided should a patient require a blood transfusion; i.e., if a patient has a common blood type and no unexpected antibodies, compatible blood for transfusion can be provided quickly; if the patient has a more unusual blood type and/or has unexpected antibodies, it may take hours to find compatible blood for transfusion The immunology/serology/molecular diagnostics laboratory department performs tests to evaluate the body s immune response, i.e., the production of antibodies and the cellular activation portion of the immune response. Some testing for infectious disease is also performed in this department. Testing in this department of the laboratory can be divided into four general categories. 1. Detection of antibodies to infectious diseases; example: anti-hepatitis C. 2. Detection of antibodies to body substances as seen in autoimmune disorders; example: rheumatoid factor antibody. 3. Detection of infectious microorganisms that are difficult or time-consuming to grow in culture; example: Mycobacterium tuberculosis. 4. Detection and quantitation of components of the immune system; examples: complement and immunoglobulin levels. A variety of analytical methods is used to detect antibodies and immune system cellular activities, from the simple (agglutination) to the sophisticated (DNA amplification). Specimens used for testing include serum, plasma, swabs containing tissue, bronchial washings, stool samples, and more. The following table identifies the tests commonly performed in this department of the laboratory. 10

11 TESTS COMMONLY PERFORMED IN THE IMMUNOLOGY/SEROLOGY/MOLECULAR DIAGNOSTICS DEPARTMENT Test Evaluates/ Measures Diagnostic Use Antinuclear antibodies (ANA) Chlamydia trachomatis Clostridium difficile Cold agglutinin titer Complement levels (C3, C4, CH 50) Cytomegalovirus (CMV) Epstein-Barr (EBV) virus Fluorescent treponemal antibody (FTA) Hepatitis B surface antigen (HBsAg) Hepatitis C antibody Detects autoantibodies against nuclear proteins Identifies the presence of this Gram-negative bacteria which is the most common sexually transmitted infection in the United States Identifies the presence of this spore-forming bacteria that causes an antibiotic-associated diarrhea Detects and quantitates IgM antibodies that attach to red blood cells resulting in a chronic anemia due to early removal of the red blood cells from the circulation Evaluates the function of the complement portion of the immune response Tests for antibodies to CMV can identify current or previous infections; testing can also be performed to identify the presence of the virus Detects the presence of the virus in a specimen; there are also tests to identify antibodies specific to EBV Detects antibodies to Treponema pallidum, confirming the presence of a syphilis infection Detects the presence of hepatitis B surface antigen; if positive it indicates the patient is infectious for HBV and can transmit the infection Detects antibodies to hepatitis C indicating a 11 Positive results are seen in systemic lupus erythematosus, rheumatoid arthritis, and other autoimmune disorders Same as evaluates/measures Same as evaluates/measures May be used with other information to diagnose cold agglutinin disease which can cause anemia and circulatory problems with the extremities Deficiencies or abnormal complement results are seen in microbial infections, autoimmune diseases, and immune-complex disorders Same as evaluates/measures Same as evaluates/measures Same as evaluates/measures Same as evaluates/measures Same as evaluates/measures past or current infection Hepatitis C genotype Identifies the type of HCV causing an infection Same as evaluates/measures Hepatitis C viral load Determines the amount of HCV in the blood Decreases in the viral load can indicate the effectiveness of treatment; increases may indicate the worsening of the disease Hepatitis panel Herpes simplex (HSV) virus Human immunodeficiency virus (HIV) antibody Human immunodeficiency virus (HIV) viral load Human papilloma virus (HPV) Immunoglobulin levels (IgG, IgM, IgE) Detects antigens and antibodies found in viral hepatitis Tests for antibodies to HSV can identify current or previous infections; testing can also be performed to identify the presence of the virus Detects antibodies to HIV indicating exposure to the virus Determines the amount of HIV in the blood Detects the presence of the virus Determines the amount of each type of immunoglobulin Determine if patient has hepatitis A, hepatitis B, or hepatitis C Same as evaluates/measures Same as evaluates/measures Decreases in the viral load can indicate the effectiveness of treatment; increases may indicate the worsening of the disease Same as evaluates/measures Decreased quantities of specific immunoglobulin types are seen in certain immune diseases

12 TESTS COMMONLY PERFORMED IN THE IMMUNOLOGY/SEROLOGY/MOLECULAR DIAGNOSTICS DEPARTMENT Test Evaluates/ Measures Diagnostic Use Immunofixation electrophoresis Infectious mononucleosis Influenza A/B Methicillin-resistant Staphylococcus aureus (MRSA) Mycobacterium tuberculosis Ova and parasites Protein electrophoresis Rapid plasma reagin (RPR) Respiratory syncytial virus (RSV) Rheumatoid arthritis (RA) factor Rubella titer Streptococcus Group A Venereal Disease Research Laboratory (VDRL) test MICROBIOLOGY TESTS Detects the presence of monoclonal antibodies to IgG, IgM, IgA, lambda light chains, and kappa light chains Tests for heterophile antibodies associated with Epstein-Barr virus infections Screening test to detect the presence of influenza A and influenza B viruses Detects the presence of MRSA in the specimen Detects the presence of Mycobacterium tuberculosis (bacteria that causes tuberculosis) in the specimen Detects the presence of and identifies the type of parasitic infection in stool specimen Quantitates the amounts of the following proteins in blood, urine, or spinal fluid: total protein, albumin, alpha-1-globulin, alpha-2- globulin, beta-globulin, and gamma globulin Screening test for syphilis (Treponema pallidum) performed on blood Detects the presence of the virus Detects autoantibodies associated with rheumatoid arthritis Evaluates past or current infection with the organism causing rubella (German measles) Screening test for group A streptococcus infection (strep throat) Screening test for syphilis (Treponema pallidum) performed on cerebrospinal fluid 12 Used to diagnose multiple myeloma and Waldenstrom s macroglobulinemia Used to diagnose infectious mononucleosis Same as evaluates/measures Same as evaluates/measures Same as evaluates/measures Same as evaluates/measures Abnormal proteins in blood and body fluids are seen in certain immune disorders Positive results indicate a possibility of a current or past infection with syphilis; confirmatory testing must be performed Same as evaluates/measures Used to assist with the diagnosis of rheumatoid arthritis Same as evaluates/measures Same as evaluates/measures Positive results indicate a possibility of a past infection with syphilis; confirmatory testing must be performed The microbiology department is responsible for the detection, isolation, and identification of pathogenic microorganisms, including bacteria, mycobacteria, molds/yeasts, viruses, and parasites. The types of specimens used for testing include anything that can be obtained from the body: urine, throat, sputum, nasopharyngeal, genitourinary tract, tissue, wounds, feces, blood, etc. Most specimens are collected by physicians or nurses using sterile swabs to collect substances from an infected area such as a wound. In most departments of the laboratory, testing is completed in a fairly rapid manner from a few minutes to a couple of hours. However, in microbiology the testing may take a day, two days, or even weeks. Much of the routine testing is performed on microorganisms that have been grown in culture and the testing is dependent upon the rate in which the microorganisms grow on various types of culture media. Some microorganisms grow faster than others do.

13 The development of molecular diagnostic techniques that allow for the detection of microorganisms in specimens without performing a culture has radically changed microbiology departments in the last two decades. For example, the microorganism that causes tuberculosis, Mycobacterium tuberculosis, can take up to 6 weeks to grow in culture. With molecular diagnostic testing, the presence of this microorganism in a specimen can be confirmed in less than 2 hours. There are now many molecular diagnostic tests available to for the detection of microorganisms that are difficult or timeconsuming to grow in culture. In many laboratories, these molecular diagnostic tests (previously discussed in the Immunology/Serology/Molecular Diagnostic section of this course) are performed in the microbiology department. The tests most frequently performed in the microbiology department are listed in the table that follows. TESTS COMMONLY PERFORMED IN THE MICROBIOLOGY DEPARTMENT Test Evaluates/ Measures Diagnostic Use Antibiotic susceptibility Determines the effectiveness of antibiotic(s) for the bacterial infection Provides specific information on the antibiotics most useful to treat Culture Aerobic/anaerobic bacteria Blood Fungal Mycobacteria Viral Infectious disease testing Occult blood URINALYSIS TESTS Process of inoculating a medium (liquid, gel, agar, or cells designed to support the growth of microorganisms) and allowing for growth of microorganisms; once growth occurs pathogenic organisms must be isolated and identified using biochemical testing; for aerobic and aerobic pathogenic bacteria, susceptibility testing is performed Process of using molecular diagnostic methods to identify the presence of a microorganism in a patient specimen without the need to grow the microorganism in culture media Test performed on fecal and gastric specimen to identify the presence of microscopic quantities of blood the bacterial infection Identification of the type of microorganism is needed to determine the most effective method of treatment Identification of the type of microorganism is needed to determine the most effective method of treatment Microscopic quantities of blood are present in the feces and gastric contents of patients with certain types of gastrointestinal bleeding The urinalysis department performs urinalysis testing. A routine urinalysis test is a screening procedure used to detect disorders and infection of the kidney, and to detect metabolic disorders such as diabetes and liver disease. A routine urinalysis exam consists of physical, chemical, and microscopic examination of the urine. The physical and microscopic exam of urine is performed by manual methods; the chemical portion of the urine exam can be done by a visual inspection or by using an analyzer. Urinalysis rarely has a department of its own; it is often part of the hematology or chemistry department. The following table identifies the components of a routine urinalysis test. 13

14 TESTS COMMONLY PERFORMED IN THE URINALYSIS DEPARTMENT Test Evaluates/ Measures Diagnostic Use Physical exam of urine Evaluates the color and clarity of the urine Color and clarity are useful indicators of the kidney s ability to concentrate urine and the Chemical exam of urine Microscopic exam of urine Performed using a reagent strip often called a dipstick; most frequently used reagent strips determine the levels of specific gravity, ph, glucose, ketones, protein, blood, bilirubin, urobilinogen, nitrate, and leukocytes Identifies and quantitates the presence of red blood cells, white blood cells, epithelial cells, casts, bacteria, yeast, parasites, casts, and crystals ANATOMIC AND SURGICAL PATHOLOGY TESTS Histology individual s hydration status Abnormal test results are useful in diagnosing diabetes, acid/base status, the early stages of liver disease, upper and lower urinary tract infections, and more The presence of cells, microorganisms, casts, and crystals in urine indicate upper/lower urinary tract infection, increased risk for kidney stone formation, and other kidney disorders The histology department of the laboratory processes and stains samples of tissues obtained from biopsy, autopsy, and surgery procedures. Processing of the specimens involves fixation with formalin and embedding in paraffin cell blocks. This preparation allows for sectioning (cutting of the tissue in sections so thin as to contain one layer of cells) using a microtome. A routine staining technique is then performed on all specimens. There are many special staining techniques performed when additional information is required. The prepared slides of specimens are referred to a pathologist for microscopic examination. Malignancy, infection, inflammation, and other disease processes are identified from the microscopic examination. Cytology The cytology department of the laboratory processes and microscopically evaluates cervical specimens using a specific method called the Papanicolaou test or Pap smear. The microscopic evaluation of cells processed by the Pap smear technique is useful in the early detection of cancer. Cytology technologists also process and microscopically evaluate body fluids for the presence of malignant cells. Any specimens identified as having malignant cells (both Pap and body fluids) are forwarded to a pathologist for review. USE OF LABORATORY TESTS IN DIAGNOSIS AND TREATMENT Laboratory test results are of vital importance in the diagnosis and treatment of disease. For some diseases, one laboratory test may provide the definitive diagnosis; for other diseases, laboratory test results may provide information that is used along with other diagnostic testing to determine a patient s disease or disorder. 14

15 This section of the course will identify diseases and disorders listed by anatomical system and the laboratory tests used for diagnosis and treatment. THE SKELETAL SYSTEM Common diseases and disorders of the skeletal system and the laboratory tests frequently used for diagnosis and treatment follow. Disease/Disorder Description Laboratory Tests Gout Type of arthritis resulting from excess Alkaline phosphatase amounts of uric acid in the blood; uric acid can build up and form crystals in the synovial Basic/comprehensive metabolic panel fluid surrounding joints, resulting in pain, Biopsy swelling, and tenderness; the big toe is often Calcium involved Calcitonin Complete blood count Osteoarthritis Most common cause of arthritis; results from Creatine kinase the wearing away of protective cartilage Erythrocyte sedimentation surrounding joints; commonly affects hands, rate neck, lower back, knees, and hips Parathyroid hormone Phosphorus Osteocondritis Results when a lack of blood supply causes Rheumatoid arthritis factor a small piece of bone and the surrounding cartilage to crack and loosen; most often Synovial fluid analysis occurs in children and adolescents and Thyroid hormones affects the knee, ankle, and elbow Uric acid Vitamin D and related forms Osteomalacia (rickets) Skeletal deformities that result from a delay in depositing calcium phosphate mineral in growing bones; most often caused by vitamin D deficiency; called rickets in children and osteomalacia in adults Osteomyelitis Osteoporosis Paget s disease Rheumatoid arthritis Infection of the bone caused by bacteria and other microorganisms Bone loss and deterioration of bone structure; most commonly caused by aging but can result from certain medications and other health issues Abnormal, enlarged, brittle bones formed as a result of a disruption in the manner in which new bone is replaced by old bone Autoimmune disorder that affects the lining of the joints resulting in swelling and stiffness; eventually bone erodes and the joints become deformed; often affects hands and feet; can also affect skin, eyes, lungs and blood vessels 15

16 THE MUSCULAR SYSTEM Common diseases and disorders of the muscular system and the laboratory tests frequently used for diagnosis and treatment follow. Disease/Disorder Description Laboratory Tests Atrophy Decrease in muscle mass due to disuse; Alanine aminotransferase may be seen in sedentary elderly individuals Aspartate aminotransferase and individuals with the inability to utilize Antinuclear antibodies their muscles, such as those with paralysis Basic/comprehensive or diseases such as muscular dystrophy metabolic panel Calcified tendonitis Biopsy Deposits of calcium in the tendons; often Complete blood count occurs in the shoulder Creatine kinase CK isoenzymes Muscular dystrophy Group of genetic muscle diseases with Gene analysis progressive muscle weakness, muscle Lactic acid wasting, and contractures Lactic dehydrogenase Muscle contusion Bruising and/or collection of blood in a Myoglobin muscle; usually a result of traumatic injury Potassium Muscle laceration Muscle rupture Myalgia Myasthenia gravis Myositis ossificans Rhabdomyolysis Tendinitis (also called tendonitis) Shallow or deep cuts in a muscle usually as a result of trauma; example: rotator cuff tears Tear in a muscle, usually results when a muscle is stretched too quickly Muscle pain Chronic progressive disorder characterized by rapid fatigue and weakness of muscles under voluntary control; caused by a breakdown in the normal communication between muscles and nerves; is an autoimmune disorder Abnormal bone formation within deep muscle tissue; often follows bone trauma but can be a hereditary disorder Release of potassium, myoglobin, and other chemicals from muscles; occurs in traumatic injury, hyper-/hypothermia, infections, and more; may lead to kidney failure, cardiac arrhythmia, and death Inflammation of a tendon, often results from overuse 16

17 THE REPRODUCTIVE SYSTEM Common diseases and disorders of the reproductive system and the laboratory tests frequently used for diagnosis and treatment follow. Disease/Disorder Description Laboratory Tests Benign prostatic Noncancerous enlargement of the prostate Acid phosphatase hypertrophy common in men over the age of 60 years; also called benign prostatic hyperplasia Basic/comprehensive metabolic panel Biopsy Cervical cancer Cancer that forms in the cells of the cervix; Complete blood count generally slow growing with little symptoms Infectious disease testing until disease is advanced; almost always (culture and/or molecular caused by infection with human papilloma diagnostic) virus Estrogen Dysmenorrhea Endometriosis Ectopic pregnancy Hydrocele Painful menstruation; can be primary (with no abnormalities present) or secondary (abnormalities present such as ovarian cyst, uterine fibroids, pelvic inflammatory disease) Condition where uterine tissue grows outside of the uterus resulting which can result in painful menstruation, heavy menstrual bleeding, and infertility Implantation of a fertilized egg outside of the uterus, often in a Fallopian tube; the fertilized egg cannot develop and it destroys surrounding tissue resulting in lifethreatening blood loss in the mother Painless buildup of fluid around one or both testicles resulting in swelling of the scrotum and groin area Fluorescent treponemal antibody Follicle stimulating hormone Human chorionic gonadotropin Luteinizing hormone Pap smear Prolactin Rapid plasma reagin Semen analysis Testosterone Thyroid hormones Tumor markers (CA-125, CEA, PSA, etc.) Viral tissue studies VDRL Hypogonadism Infertility Ovarian cancer Ovarian cyst Diminished production of hormones by the testes or ovaries Inability of a female to get pregnant after trying for a year; may be due to a single cause in either the male or female, or a combination of factors Cancer that begins in one or both of the ovaries; often not detected until it has spread spreads throughout the pelvic and abdominal cavities Fluid-filled sac on an ovary; most are harmless, present with little or no symptoms, and resolve without treatment; some may cause significant pain and may even rupture resulting in symptoms of shock that require immediate medical treatment 17

18 Disease/Disorder Description Laboratory Tests Pelvic inflammatory disease Irreversible damage to the uterus, ovaries, fallopian tubes, or other parts of the female reproductive system caused 90% of the time by sexually transmitted infections with Chlamydia trachomatis or Neisseria gonorrhea; the primary preventable cause of infertility in women Prostate cancer Sexually transmitted infections/diseases Testicular cancer Uterine cancer Cancer of the prostate, the small gland that produces seminal fluid; may grow slowly and need minimal treatment or may be aggressive and grow rapidly, spreading outside of the prostate gland A group of viral, parasitic, and bacterial infections that are spread through sexual activity; may be called venereal diseases; more than 30 microorganisms may be transmitted through sexual contact Cancer occurring in one or both of the testes; highly treatable and the most common cancer in American males ages Also called endometrial cancer; development of cancerous cells in the endometrial lining of the uterus; usually occurs in women over the age of 50; usually diagnosed in the early stages when it is highly treatable THE DIGESTIVE SYSTEM Common diseases and disorders of the digestive system and the laboratory tests frequently used for diagnosis and treatment follow. Disease/Disorder Description Laboratory Tests Appendicitis Inflammation of the appendix usually Alanine aminotransferase requiring surgical removal Amylase Barrett s esophagus Condition where the normal tissue lines the Basic/comprehensive metabolic panel esophagus is replaced with the tissue that Bilirubin lines the intestine; people with this condition Biopsy are at high risk for esophageal cancer Carcinoembryonic antigen Carotene Cancer Cancer can occur in any of the digestive Cholesterol system organs from the top (mouth and Complete blood count salivary glands) to the bottom (rectum/anus); Fecal fat some are more treatable than others; some Folate have poor survival rates Gamma glutamyl transferase Celiac disease Autoimmune disorder that damages the Glucose lining of the small intestine resulting in a Infectious disease testing digestive disorder (culture or molecular diagnostic) Lipase Occult blood Triglycerides 18

19 Disease/Disorder Description Laboratory Tests Cirrhosis Scarring (fibrosis) of the liver caused by liver diseases and conditions, such as hepatitis Continued and chronic alcohol abuse Vitamin B12 Cholecystitis Colitis Crohn s disease Diverticulitis Diverticulosis Gastroesophageal reflux disease (GERD) Gastrointestinal hemorrhage Gastritis Gastroenteritis Hepatitis Inflammatory bowel disease Inflammation of the gallbladder; may require surgical removal Inflammation of the colon, usually refers to large intestine; results in abdominal pain, diarrhea with or without blood, and with or without pain; has several causes Chronic inflammatory disease of the intestines, mostly the small intestine; results in diarrhea which is often bloody, abdominal pain, and weight loss Painful disorder that occurs when pouches (diverticula) that form in the wall of the large intestine become inflamed or infected; may require surgical removal of the diseased portion of the colon Formation of pouches (diverticula) in the wall of the large intestine; may or may not progress to diverticulitis A chronic condition where the acidic contents of the stomach backwash into the esophagus causing irritation and discomfort; may require treatment with prescription drugs to prevent the development of Barrett s esophagus Loss of blood from any portion of the digestive system, usually refers to bleeding from the small or large intestine; can be chronic or acute; may require blood transfusion Inflammation or irritation of the lining of the stomach Inflammation of the lining of the intestines caused by a virus, bacteria or parasites; results in diarrhea; often called the stomach flu but it is not caused by the influenza virus Inflammation of the liver; caused by toxins, viruses, drugs (prescription and nonprescription), and more Involves inflammation of all of the digestive tract; general terms that includes Crohn s disease and ulcerative colitis 19

20 Disease/Disorder Description Laboratory Tests Lactose intolerance The inability to digest lactose, a natural sugar found in milk and dairy products; caused by the lack of an enzyme called lactase Malabsorption syndromes Pancreatitis Peptic ulcer disease Peritonitis Ulcerative colitis Number of conditions resulting in the inability of the body to absorb nutrients from digestion Inflammation of the pancreas Presence of painful sores called ulcers in the stomach; usually caused by the bacteria Helicobacter pylori and is treated with antibiotics; can be caused by tumors of the cells that increase acid production in the stomach Inflammation or irritation of the peritoneum, the thin tissue that lines the inner wall of the abdomen and covers most of the abdominal organs; has many causes, some requiring immediate treatment to avoid serious consequences including death A bowel disease where long-lasting inflammation and ulcers develop in the innermost lining of the large intestine and rectum; can be debilitating and lead to lifethreatening complications THE ENDOCRINE SYSTEM Common diseases and disorders of the endocrine system and the laboratory tests frequently used for diagnosis and treatment follow. Endocrine Gland Disorder/Description Laboratory Tests Pituitary Acromegaly: Production of too much growth Adrenocorticotropic hormone hormone in adulthood; results in growth of Aldosterone the bones, especially those of the face, Antidiuretic hormone hands, and feet; may cause life-threatening Basic/comprehensive illnesses; usually the result of a tumor of the metabolic panel pituitary gland Biopsy Calcium Growth hormone deficiency dwarfism: Complete blood count failure of the pituitary to produce growth Cortisol hormone in adequate quantities; results in a form of dwarfism; can be treated with Vitamin D injections of growth hormone Erythropoietin Glucagon Gigantism: excessive growth of height and Glucose tolerance test body parts of children due to excess Growth hormone production of growth hormone; very rare; Insulin usually the result of a pituitary gland tumor Parathyroid hormone Phosphorus Prolactin Renin 20