FULL BLOOD COUNT PRESENTATION

Clinical 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: o uterine e.g. menorrhagia o gastrointestinal o malignancy

increased demands: o pregnancy o prematurity o growth

others: o malabsorption e.g. gastrectomy, coeliac disease o 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

FBCHb 65 g/L 115-165

MCV 74 fL 80-100

Platelets 500 X 109/L 150-400 X 109/L

Serum ferritin 5ug/L 10-230

Serum B12 220pmol/L 120-680

Serum folate 2.0nmol/L 7-45

Red cell folate 100nmol/L 360-1400

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: LOWThus 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 14 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