Lab Guide Hematology Section Lab Guide

Transcription

1 Lab Guide Hematology Section Lab Guide

2 Activated Partial Thromboplastin Time (APTT) One tube 2.7 ml citrated blood sample filled up to the mark on the tube label. (Light blue top tube, citrated 3.2%) For pediatric patients below 1 year: One Tube 1.0 ml pediatric tube filled up to the mark on the tube label (Light blue top tube, citrated 3.2%) *In case of high hematocrit (>55%) contact the lab before extracting blood for all coagulation testing because special tube(s) will be provided. STAT: 1hr Routine: 4hrs Automated The Reference Range is reported with each patient s result. This may vary with the reagent lot and also from one hospital to the other depending on the machine/reagent combination in service. Heparin therapeutic range This is the APTT range in seconds corresponding to an unfractionated heparin (UFH) concentration of 0.3 to 0.7 U/mL as assessed by anti Xa assay. The test is useful to monitor patients under UFH therapy. Rejection Criteria The APTT is an assessment of the intrinsic and common pathways of blood coagulation. It is prolonged in deficiency of prekallikrein, HMWK (High Molecular Weight Kininogen), factor XII, XI, IX, X, V, II and fibrinogen, or by inhibitors directed against any of these factors.. See Management of Laboratory (CL 7067). Performing Lab Location AKH Hematology Lab :

3 Bone Marrow Bone marrow aspirate, trephine biopsy (in addition to peripheral smear) all prepared at the bed side After appointment Routine : 7 working days. A preliminary verbal or written report will be issued on aspirate within 8 hrs for urgent cases ONLY Aspirate: Smears are immediately prepared and air dried. The rest of the aspirate is allowed to clot for preparation of clot sections. If immunophenotyping or cytogenetic studies are needed, parts of the marrow aspirate will be added to the appropriate containers. --- Biopsy: Using a Jamshidi needle, the physician obtains a biopsy which is sent in formalin to the Histopathology lab for processing Examination of Bone marrow is done to rule out marrow pathology. Final interpretation is done through integration of peripheral blood, bone marrow aspirate and trephine biopsy findings, together with the results of supplementary tests such as immunophenotyping, cytogenetic analysis and molecular genetic studies as appropriate, in the context of clinical and other diagnostic finding Rejection Criteria. See Management of Laboratory (CL 7067).

4 Body Fluids Analysis (CSF, Pleural, Pericardial And Synovial) 2-5 ml body fluids collected in glass or plastic tubes, using appropriate anticoagulant, if necessary, for analysis (as those containing EDTAor Heparin). CSF samples preferably collected in sterile glass or plastic tubes numbered according to order of draw (preferably tube# 3), EDTA tube can be used for bloody samples /Ref 4 hrs Macroscopic and microscopic evaluation of body fluid with total and differential cell counting. RBC WBC CSF Adults 0 2 / μl 0-5 / μl Neonates 0-2 / μl 0-30/ μl Pleural 0-10,000/ μl <1000/ μl Peritoneal /Pericardial 0-10,000/ μl <500/ μl Synovial /μl <200/ μl Normal range for the differential cells of the body fluid. CSF Adults Lymphocytes 40-80% Monocytes/Macrophage 15-45% Neutrophills 0-6% Synovial PMN (polymorphs) - Less than 25% All other fluids Mononuclear cells, including lymphocytes, monocytes, macrophages and synovial lining tissue cells are the primary cells seen in normal synovial fluid. PMN -Less than 25% Macrophages and mesothelial cells may be present. Fluid analysis is done to assist in the diagnosis or exclusion of diseases and subarachnoid hemorrhage (CSF) Rejection Criteria. See Management of Laboratory (CL 7067).

5 Bone Marrow Iron Stain Air dried bone marrow aspirate smears As approved by haematopathologist Reported within the BM report. Prussian Blue reaction Normal Reduced or depleted iron store is seen in iron deficiency anaemia while it is increased in anaemia of chronic disorders and haemosiderosis. Abnormal sideroblasts and ringed sideroblasts are seen in myelodysplastic syndrome and sideroblastic anaemia. Increased sideroblasts are seen in megaloblastic anemia, alcoholism and following splenectomy. Rejection Criteria See Management of Laboratory (CL 7067);.

6 Complete Blood Count (CBC) - Coulter Profile Whole blood (3 ml) in EDTA Tube. Samples must reach the lab as soon as possible but not later than 2 hours after collection /Refrigerated STAT- 1 hr Routine - 4 hrs Automated. This comprises estimation of Hemoglobin (Hb), Hematocrit (Hct), Red Blood Cells (RBC) count, White Blood Cells (WBC) count, RBC indices; platelet count ± automated differential count ± reticulocyte count. See Table 1 An essential test for the diagnosis and follow up of various haematological and nonhaematological diseases. See Management of Laboratory (CL 7067); Rejection Criteria Day 0-2 Day 3-6 RBCs Hb Day Day Day Day M 7M - 2 Yrs 2-6Y 6-12Y Adults PCV MCV M F M F M F

7 MCH MCHC Retic WBCs Neutro Lympho Mono Eoso Baso Platelets

8 D-Dimer One Tube 2.7 ml citrated blood sample 3.2 % (blue top tube) For pediatric patients below 1 year: One Tube 1.0 ml pediatric tube filled up to the mark on the tube label (Light blue top tube, citrated 3.2%) *In case of high hematocrit (>55%) contact the lab before extracting blood for all coagulation testing because special tube(s) will be provided. STAT: 1hr Routine: 4hrs Automated The Reference Range is reported with each patient s result. This may vary with the reagent lot and also from one hospital to the other depending on the machine/reagent combination in service. D-dimer is produced by the digestion of cross-linked fibrin by plasmin. A positive test is seen in thrombosis, PE and many other situations including DIC, post-surgery, trauma, infection, malignancy, pregnancy, atherosclerosis and in the elderly. D-Dimer test has been cleared by the Food and Drug Administration (FDA) to exclude deep vein thrombosis (DVT) and pulmonary embolism (PE) at a cut-off of 0.50mg/L FEU* in patients where a physician's Pretest Probability assessment (PTP) indicates a non-high probability of pulmonary embolism (<0.50mg/L FEU* is considered negative). * Cut off value may vary between labs operating different instrument/reagent. This is noted in patients' reports. Disclaimer: If D-Dimer test is used for clinical conditions other than exclusion of deep vein thrombosis (DVT) or pulmonary embolism (PE), then the test should be used as an aid in the diagnosis. Rejection Criteria See Management of Laboratory (CL 7067);.

9 Eosinophils in Urine Rejection Criteria 10ml urine. First voided morning sample and immediately delivered to the lab. 1 day Wright stained smear Negative Non-invasive test to aide in the diagnosis of Acute Interstitial Nephritis.

10 Erythrocyte Sedimentation Rate 3.0 ml in EDTA (Lavander Top) tube. (Can be a part of CBC) /Ref 1 day Automated Age Sex Reference Range 0 14 years W / M 2 34 mm/hr years W 2 37 mm/hr years M 2 28 mm/hr years W 2 39 mm/hr years M 2 37 mm/hr > 70 years W / M 3 46 mm/hr W: Women; M: Men ESR is useful in disorders associated with an increased production of acute-phase proteins. It is non-specific and will be raised in any inflammatory condition. Low normal results are obtained in cases of polycythemia. Rejection Criteria See Management of Laboratory (CL 7067);

11 Fibrinogen One tube 2.7 ml citrated blood sample filled up to the mark on the tube label. (Light blue top tube, citrated 3.2%) For pediatric patients below 1 year: One Tube 1.0 ml pediatric tube filled up to the mark on the tube label (Light blue top tube, citrated 3.2%) *In case of high hematocrit (>55%) contact the lab before extracting blood for all coagulation testing because special tube(s) will be provided. STAT: 1hr Routine: 4hrs Automated. Fibrinogen determination by Clauss method. An excess of thrombin converts fibrinogen to fibrin. The time taken for the clot to form is directly proportional to the concentration of fibrinogen in the sample. The Reference Range is reported with each patient s result. This may vary with the reagent lot and also from one hospital to the other depending on the machine/reagent combination in service. Diagnosis of hypofibrinogenaemia and DIC screen Rejection Criteria See Management of Laboratory (CL 7067);.

12 Haemoglobin H Inclusion 3ml in EDTA tube 2 working days Supravital stain Negative As adjuvant in the diagnosis of alpha thalassaemia. Rejection Criteria See Management of Laboratory (CL 7067);

13 Haemosiderin in Urine Minimum 5.0ml of freshly voided urine (preferably,first morning collection) collected in sterile plastic urine container without any preservative. Working days, morning shift only one day Prussian blue reaction Negative Diagnosis of intravascular haemolysis. Rejection Criteria See Management of Laboratory (CL 7067);.

14 Heinz Body Inclusions Rejection Criteria Freshly drawn whole blood using heparin or EDTA as anticoagulant /Refrigerated 1 day Heinz bodies represent precipitated denatured Hb and appear as single or multiple, round/oval bodies in RBC on blood film stained with supravital stain. Negative Heinz bodies are found in the presence of unstable Hbs (such as Hb Zurich), in splenectomized patients, in some hemolytic disorders. e.g. G6PD deficiency and glutathione deficiency. See Management of Laboratory (CL 7067)

15 Kleihauer Test 1ml whole blood in EDTA tube in addition to 1ml cord blood in EDTA tube to serve as positive control. /Refrigerated Within 72 hours This is a quantitative cytochemical test for the detection of HbF- containing red cells. No fetal RBCs present. The test is used to detect fetal RBCs in maternal circulation, thus estimating the amount of transplacental hemorrhage (TPH) in cases of feto-maternal Rh incompatibility or unexplained fetal anemia. If four or less fetal cells are seen using a 40x objective, this means that no more than 4 ml of fetal red cells are present in the maternal circulation. The test is also used in case of high HbF levels to detect hereditary persistence of fetal hemoglobin (HPFH). Rejection Criteria See Management of Laboratory (CL 7067);

16 Malaria - Blood film for Malaria 1 ml whole blood in EDTA tube or as part of CBC specimen. STAT: 3hrs Routine: 1 day Thin and thick smears. The thick smear is used as a screening test to establish the presence of parasite and the thin smear is used to identify species. Rejection Criteria Negative Diagnosis of malaria infection.

17 Microfilaria 3.0 ml. in EDTA tube (Can be a part of CBC) STAT: 3hrs Routine: 1 day Detection and identification of microfilaria is done by direct visualization of the parasite using slides stained with Wright stain. Negative Filariasis involving the lymphatics is the cause of elephantiasis. It is caused by the filarial worms Brugia malayi, Wuchereria bancrofti & Brugia timor, whereas filarial infection of the subcutaneous tissues is caused by Loa Loa. The larvae are transmitted by mosquito to humans where they can be found in the blood and where they show periodicity with fluctuating levels at different times of the day. Rejection Criteria See Management of Laboratory (CL 7067);

18 Manual Differential count 3ml EDTA blood (or as part of the CBC) 2 working days Examination of Wright stained smear See table 1 As a re-check of the automated count. Rejection Criteria See Management of Laboratory (CL 7067);.

19 Mixing study (using PT or APTT) 3 tubes, each 2.7 ml citrated blood sample 3.2% (blue top tube) *In case of high hematocrit (>55%) contact the lab before extracting blood for all coagulation testing because special tube(s) will be provided. 2 working days The test is performed by mixing the patient s plasma with Pooled Normal Plasma (PNP) and repeating the clotting test (PT and/or APTT) in question immediately and after an established incubation period. Mixing is done when prolongation of PT is >3.0 seconds or APTT >5.0 seconds above the upper limit of the reference range. Mixing for shorter prolongation will follow the pathologist s decision. --- Investigation of an unexplained prolongation of PT or APTT. Correction indicates a possible factor deficiency, whereas failure to correct suggests the presence of inhibitor. If both the PT and APTT are prolonged, the problem is likely to be in the final common pathway. If only APTT is prolonged, the problem lies in the intrinsic pathway. If the APTT is normal and PT is prolonged then the problem lies in the extrinsic pathway. Rejection Criteria See Management of Laboratory (CL 7067);

20 Prothrombin Time (PT) One tube 2.7ml citrated blood sample filled up to the mark on the tube label. (Light blue top tube, citrated 3.2%) For pediatric patients below 1 year: One Tube 1.0 ml pediatric tube filled up to the mark on the tube label (Light blue top tube, citrated 3.2%) *In case of high hematocrit (>55%) contact the lab before extracting blood for all coagulation testing because special tube(s) will be provided. STAT: 1hr Routine: 4hrs Automated The Reference Range is reported with each patient s result. This may vary with the reagent lot and also from one hospital to the other depending on the machine/reagent combination in service. Assessment of the extrinsic and common pathways of blood coagulation. It is prolonged in deficiency of factor II, V, VII, X and fibrinogen or in presence of an inhibitor to any of these factors. Monitoring of Warfarin therapy. Rarely reagents used in different labs may show high sensitivity to lupus anticoagulant in the patient s plasma. It is recommended that such patients are monitored in the same lab. Rejection Criteria See Management of Laboratory (CL 7067);

21 Peripheral Smear Smears spread from EDTA blood. 2 working days This is a thin film examined for morphological assessment of RBC, WBC and Platelets. Peripheral smears are prepared from CBC samples according to criteria set by the lab. --- Rejection Criteria Peripheral smear examination is of unquestionable value in sorting out hematological abnormalities.

22 Platelet Estimation in Peripheral Smear Smears spread from EDTA blood. 2 working day Platelets are estimated in Wright- stained peripheral smear See table 1 Rejection Criteria Re-checking platelet count in questionable automated result

23 Platelet function Test -PFA (in Vitro Bleeding time) Two tubes, each 2.7 ml citrated blood sample 3.2 % (blue top tube) + one EDTA tube 4 hrs Automated. Whole blood is incubated at 37 C and subjected to high sheer within a capillary tube. The blood flows through an aperture within a membrane coated with the platelet agonists collagen and ADP/Epinephrine. Platelets adhere to the membrane and aggregate to form a plug within the aperture. The change in flow rate of the blood with time is recorded as a closure time in seconds EPI: sec ADP: sec Prolonged PFA closure times in different patterns are seen in patients under antiplatelet medications, hereditary and acquired platelet disorders. Rejection Criteria See Management of Laboratory (CL 7067);.

24 Reticulocyte Count Whole blood (1 ml) in EDTA tube or as part of the CBC specimen. /Refrigerated 4 hrs A supravital stain is used to stain remnants of RNA in the cytoplasm of young RBCs (reticulocytes). The number of reticulocytes in 1000 RBCs is determined and reported as %. Currently automated CBC analyzer is used for reticulocyte counting. Adults % Pediatric reference ranges with be released with the patient s report according to the age. Reticulocyte count is an index of red cell production by the bone marrow. Increased reticulocyte count occurs in compensated anemias e.g. haemolysis, bleeding etc; while decreased reticulocyte count occurs in marrow failure as in aplastic anemia. Rejection Criteria See Management of Laboratory (CL 7067);

25 Sickling Test Whole blood (2 ml in EDTA Tube or as part of CBC sample) /Ref 2 working days Sickling test may be requested alone or is done as part of Hb electrophoresis. Sodium Metabisulfite method: Whole blood is mixed with a strong reducing agent that deoxygenates hemoglobin. The mixture is then sealed to prevent reoxygenation. If HbS is present, sickle shaped red blood cells are formed. Negative Positive Sickling test occurs in Hb S disease, sickle cell trait and Hb S/C double heterozygosity. Rejection Criteria See Management of Laboratory (CL 7067);

26 Thrombin Time (TT) One tube 2.7ml citrated blood sample filled up to the mark on the tube label. (Light blue top tube, citrated 3.2%) *In case of high hematocrit (>55%) contact the lab before extracting blood for all coagulation testing because special tube(s) will be provided. STAT: 1hr Routine: 4 hrs Automated, based on Clauss method. Thrombin is added to plasma and the clotting time recorded. The Reference Range is reported with each patient s result. This may vary with the reagent lot and also from one hospital to the other depending on the machine/reagent combination in service. Prolonged TT is seen in hypo- and dysfibrinogenaemia, heparin contamination and high FDPs as in DIC and liver diseases. Rejection Criteria See Management of Laboratory (CL 7067);