HEAMATOLOGICAL INDICES AND BONE MARROW BIOPSY

Transcription

1 HEAMATOLOGICAL INDICES AND BONE MARROW BIOPSY

2 HEMATOCRIT Hematocrit is a measure of the percentage of the total blood volume that is made up by the red blood cells The hematocrit can be determined directly by centrifugation ( spun hematocrit ) The height of the red blood cell column is measured and compared to the column of the whole blood

3 CENTRIFUGED BLOOD (NORMAL) Plasma Normal Hct in adult males 40-54% Normal Hct in adult females 34-51% Buffy coat (WBCs and Platelets) Red blood cells

4 CENTRIFUGED BLOOD (ADULT MALE OR FEMALE) WHAT IS YOUR DIAGNOSIS? Plasma Buffy coat Anemia there is a low percentage of RBCs (low hematocrit) RBCs

5 CALCULATING THE HEMATOCRIT More commonly the Hct is calculated directly from the RBC and MCV Hematocrit % = RBC (cells/liter) x MCV (liter/cell) Because the Hct is a derived value, errors in the RBC or MCV determination will lead to spurious results

6 MEAN CORPUSCULAR VOLUME The MCV is a measure of the average volume, or size, of an RBC It is determined by the distribution of the red blood cell histogram The mean of the red blood cell distribution histogram is the MCV

7 RED CELL DISTRIBUTION HISTOGRAM Number Of cells MCV Cell Size (fl)

8 USE OF MCV RESULT The MCV is important in classifying anemias Normal MCV = normocytic anemia Decreased MCV = microcytic anemia Increased MCV = macrocytic anemia

9 RED CELL DISTRIBUTION HISTOGRAM Number Of cells Microcytic Red blood cells Macrocytic Red blood cells MCV Cell Size (fl)

10 PURPOSE FOR PERFORMING RBC INDICES: ( I ) Morphologic classification of anaemia. ( II ) To correlate Hb estimation and RBC count

11 I. Mean cell volume ( MCV ) : MCV is the average volume of red cubic micrometers or femtolitre. MCV = PCV x 10 / RBC count in millions/cmm. It is expreesed in femtolitre. Normal range: micrometer or femtolitre. cells. It is expressed in

12 II. Mean cell haemoglobin ( MCH ) : MCH is the content (weight) of haemoglobin of average red cell.it is expressed in picograms or micromicrograms. MCH = Hb (in gms/ 100ml)/ RBC count( in millions/cmm) x 10. It is expressed in picogram or micromicrogram. Normal range: picograms or micromicrograms.

13 III. Mean cell Heamoglobin concentration ( MCHC ): It is the average concentration of haemoglobin given volume of packed red cells. MCHC = Hb (in gms/100ml) / PCV - expressed in percentage. Normal range :33 to 36 % in a

14 Abnormal Indices : In microcytic anaemias, indices are decreased, with MCV upto 50 fl, MCH upto 15 pg, MCHC upto 22 % In macrocytic anaemias, the values may be as high as MCV upto 150fl, MCH upto 50 pg with normal or decreased MCHC. The MCHC increases only in spherocytosis, it rarely is over 35 %.

15 BONE MARROW BIOPSY

16 BONE MARROW Bone marrow differentiates into myeloid, erythroid and lymphoid cell lineages under the influence of cytokines or growth factors. Function: supply mature hematopoietic cells into peripheral blood and respond to demands

17 BONE MARROW Highly vascularized loose connective tissue Organized around bone vasculature Located between trabeculae of spongy bone Composed of 2 major compartments Hematopoietic Vascular

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19 INDICATIONS FOR BM EVALUATION Hematological and nonhematological disorders often requires BM evaluation for Diagnosing Managing Making prognoses Following up on disorders Bone marrow should be evaluated together with Peripheral blood counts Peripheral blood smear

20 INDICATIONS FOR BONE MARROW STUDY :- In microcytic anemias - evaluation of the iron stores and sideroblasts allows categorization of the anemia i.e. iron deficiency, anemia of chronic diseases,sideroblastic anemia. In macrocytic anemias - to confirm whether the process is megaloblastic or not. In normocytic anemias without an increased reticulocyte production index - evaluation for quantitative or qualitative abnormalities in erythropoiesis.eg. pure red cell aplasia, myelodysplasia

21 In neutropenia, thrombocytopenia or pancytopenia Helpful in assessing the presence and normality of the precursor cells in each series One can assess - Decreased production Impaired maturation Increased destruction as the mechanism of the disorder.

22 In cytopenias - sometimes presence of Leukemia or other hematologic neoplasia. Confirmation of diagnosis in immunoglobulin abnormalities - Plasma cell myeloma Macroglobulinemia Trephine biopsy is indicated for -

23 For assessing marrow cellularity Following the administration of antineoplastic drugs. To assess the status of engraftment Following bone marrow transplantation To investigate the patients with Infectious diseases Metabolic disorders

24 Evaluation of patients with Malignant lymphoma Leukemia Metastatic tumor Granulomatous disorders Myelofibrosis Aplastic anemia Plasma cell dyscrasias

25 BONE MARROW PROCEDURE Sites of hematopoiesis Differ by age Certain disease states Red marrow can extend into long bones Cellularity within red marrow decreases with age Adipose tissue replaces hematopietic tissue

26 BONE MARROW PROCEDURE Marrow specimens After adolescence Posterior superior iliac crest Occasionally sternum and anterior iliac crest < 2 years of age Anterior tibia Older children Spines of the lumbar vertebral bodies L1 and L2

27 BONE MARROW PROCEDURE Equipment Use sterile technique Make direct smears from the aspirate Make crush smears from the marrow spicules Place extra aspirate into anticoagulated tubes Performance of the preliminary exam and processing

28 BONE MARROW EQUIPMENT Bone marrow aspirates and biopsies Obtained using disposable needles Jamshidi trephine needle (8 or 11 gauge) Sterile technique always used

29 JEMSHIDI TREPHINE SALAH ASPIRATION NEEDLE

30 PROCESSING THE SPECIMEN IN THE LAB Place EDTA specimen (liquid aspirate) in Wintrobe tube and centrifuge at low speed. Measure layers formed by centrifugation FPV - fat and perivascular used for iron stain Plasma Buffy coat (myeloid:erythroid cells- M:E) Normal is 4:1. M:E is the ratio between all granulocytes and their precursors and all nucleated red cell precursors. RBC s

31 PROCESSING THE SPECIMEN : Prepare and stain ME smears. Deliver clot remaining in syringe and biopsy to histology for processing. Deliver other specimens obtained such as viral, fungal or routine culture specimens to microbiology.

32 INFORMATION DERIVED FROM SPECIMENS Direct smear from syringe tip - evaluation of cellular morphology with Wright s stain Particle (crush) smear - evaluation of cellularity and the relationship of cells to each other M:E smear - evaluation of hematopoietic cells and M:E ratio Biopsy If marrow cannot be aspirated ( dry tap ), this is the only specimen for examination Examination for malignancy for clinical staging of lymphomas and cancers Examination of the architecture of the bone marrow and the cells in their natural relationship to each other Trephine imprint (touch prep) - examination of cells with Wright s stain; may be the only source to study cellular detail if an aspirate is not obtained

33 Thank You