FULL BLOOD COUNT PRESENTATION Clinical Practice A

FULL BLOOD COUNT PRESENTATIONClinical Practice A GROUP C

Iron Deficiency Anaemia • Caused by a lack of adequate iron to synthesize haemoglobin and meet body demands in such as during periods of rapid growth and pregnancy • Usually due to a diet insufficient in iron or from blood loss • Diagnosis includes - Often, the platelet count is elevated (>450,000X109/L) - WBC is usually within reference ranges

Iron Deficiency • blood loss: • uterine e.g. menorrhagia • gastrointestinal • malignancy • increased demands: • pregnancy • prematurity • growth • others: • malabsorption e.g. gastrectomy, coeliac disease • dietary iron deficiency

Investigation and Diagnosis Biochemistry: • decreased serum ferritin - best biochemical marker • increased total iron binding capacity (TIBC) • decreased TIBC saturation - less than 30%; often the best parameter with which to monitor treatment • decreased serum iron

Investigation and Diagnosis Haematology: • microcytic, hypochromic anaemia • blood film shows occasional target cells and pencil-shaped poikilocytes • platelet count may be at or above the upper limit of normal if there is persistent bleeding • The best proof of iron deficiency anaemia is that the anaemia is cured by administration of iron.

Microcytosis • Defined as a reduced mean cell volume – average volume of a single red cell - of less than 80 femtolitres in adults (norm range 80-100 fl) • Characterized by the presence of microcytes (abnormally small red blood cells) in the blood.

Causes • iron deficiency anaemia - the commonest cause • Vit A, C, copper deficiency • sideroblastic anaemia • thalassaemias • anaemia of chronic disease • lead poisoning

Clinical Features • Possible symptoms: • pallor • fatigue • dyspnoea • anorexia • headache • bowel disturbance

Investigation • to investigate microcytic anaemia , patient has a blood film, then serum iron levels are measured. • blood film - iron deficiency anaemia has a microcytic, hypochromic blood film showing anisocytosis and poikilocytosis • serum iron, ferritin and total iron binding capacity: - iron deficiency anaemia - low serum iron, low serum ferritin, raised TIBC - other causes are iron loading conditions characterised by raised serum iron, raised ferritin, low total iron binding capacity

Patient Investigation • FBC

Case History • 25 year old female • Suspected iron deficiency anaemia • Never been pregnant, no change in menstrual flow • Normal diet/No medications • No GIT problems • Low MCV • High platelets • Normal Serum B12 • Low Serum Folate • Low Red Cell Folate • Low haemoglobin

Is the MCV result consistent with a diagnosis of iron deficiency? • Yes in iron deficiency anaemia, MCV is low, however microcytosis is not always caused by iron deficiency anaemia • WHY?

Because… • In the majority of cases, microcytosis is the result of impaired hemoglobin synthesis. Disorders of iron metabolism and of porphyrin and heme synthesis, as well as impaired globin synthesis, lead to defective hemoglobin production and to the generation of microcytosis.

Could this patient also have associated B12 or folate deficiency? • Serum folate, RBC folate and Vitamin B12 levels differentiate between folate and B12 deficiency • The patient: • Low haemaglobin: anaemia • Serum B12: Normal • Serum folate and RBC folate: LOW Thus there is a folate deficiency

Folate Deficiency • Low folate levels can cause macrocytic anaemia – indicated by high MCV • The patient has a low MCV - indicates microcytic anaemia due to iron deficiency

Anisocytosis • However, blood film showed anisocytosis: RBC are of unequal size (large and small) • Patient can have both  iron deficiency anaemia: small size RBC  folate deficiency anaemia: large size RBC

Main causes of folate deficiency • Dietary – inadequate intake (Common) • Blood loss • Increase physiological requirements eg infant growth or pregnancy • Malabsorption due to GIT problems eg Coeliac disease, Crohn’s disease • Other: Drugs eg Phenytoin, Trimethoprim, Methotrexate, Oral Contraceptives  Patient doesn’t display any of these factors

Is the data typical for patient’s with iron deficiency anaemia? • Data is normal as in iron deficiency anaemia, patients display low MCV and low serum ferritin levels • Folate levels are not normally low in iron deficiency anaemia. Thus the levels must be investigated for other possible causes.

Patients Blood Film Shows: • Hypochromic, Microcytic Cells • Marked Anisocytosis • Piokilocytosis - Pencil Cells - Target Cells • Occasional Howell-Jolly Bodies • Hypersegmented Neutrophils

Anisocytosis • RBC show abnormal size variation • Normal RBC diameter = 6-8 µm. Grades 14 depending on % of abnormality • Normal RDW (Red cell Distribution Width) is 11.5 -14.5. Increased RDW suggest anisocytosis • Significance: Sign of many anaemias - Iron deficiency, Vit B12 deficiency

Target Cells • Target cells AKA Codocytes • Characterised by thin “bulls-eye” shape and an increase in the surface membrane area to volume ratio due to a decrease in Hb • Significance: A sign of Iron Deficiency Anaemia, Vit B12 deficiency Anaemia and other disorders eg Liver Disorders, Thalassemia,

Pencil Cells • Oval to elongated, ellipsoid shape with central area of pallor and hemoglobin at both ends of cell • Significance: Iron deficiency anaemia (Elongated cells), Vitamin B12 deficiency anaemia (Oval Cells), can also be Inherited, where by >25% elliptocytes are oval.

Howell-Jolly Bodies • Smooth, round nuclear fragments made up of DNA • Observed when erythropoiesis is active • >3% is significant and indicates Megaloblastic Anaemia

Hypersegmented Neutrophils • Neutrophils with five or more lobes • Significance: an important clue to the presence of deficiency of vitamin B12 or folic acid

Conclusion • Patient FBC and Blood film suggest: Iron Deficiency Anaemia AND Folate Deficiency Anaemia As evidenced by Low MCV and Low Folate combined with the presence of Hypochromic, Microcytic Cells, Marked Anisocytosis, Howell-Jolly Bodies, Hypersegmented Neutrophils

FULL BLOOD COUNT PRESENTATION Clinical Practice A