Evaluation of Vitamin B12 and Folate Levels in Megaloblastic Anaemia,Diagnosed Morphologically,at the University Teaching Hospital,lusaka,Zambia

Abstract

Vitamin B12 and folate deficiency is a well-known health problem. Deficiencies of folic acid and vitamin B12 are known to cause megaloblastic anaemia, which is characterised by presence of abnormally large erythrocyte precursor cells, megaloblasts, in the bone marrow and macrocytic red cells in the peripheral blood. These megaloblasts arise because of impaired deoxyribonucleic acid (DNA) synthesis followed by ineffective erythropoiesis. However, vitamin B12 or folate levels have not been described in Zambia, whether normal levels or in relation to anaemia. The study aimed to determine vitamin B12 and folate levels in megaloblastic anaemia, diagnosed morphologically, in patients at the University Teaching. This was a case control study which was undertaken at the University Teaching Hospital (UTH) in Lusaka, Zambia. Full blood count (FBC), Peripheral smears and ELISA were assessed on blood samples received from megaloblastic anaemia and non-anaemic patients. The age range was between 18 – 54 years (Mean age-31 years). Among the 40 megaloblastic patients, 35% (14/40) were male and 65% (26/40) were female with a male to female ratio of 1:1.9. Full blood count and peripheral smear findings revealed that bicytopenia was present in 22.5% (9/40) and pancytopenia in 72.5% (29/40) patients. Furthermore, the results showed megaloblastic anaemia participants had statistically significant lower median vitamin B12 concentration 175 (150-333)pg/ml than non-anaemic control participants 299.5 (238-571)pg/ml =0.0001. Megaloblastic anaemia participants also had a statistically significant lower folate concentration (12.32± 2.28 ng/ml) than non-anaemic control participants (19.28 ± 2.84 ng/ml) =0.029. Of the megaloblastic anaemia patients, vitamin B12 deficiency was in 60% (24/40), pure folate deficiency in 30% (12/40) and combined deficiency was observed in 15% (6/40) patients. A weak negative correlation was found between vitamin B12 and mean corpuscular volume but statistically significant (r= 0.0278, =0.001). However, there was no statistical significant correlation between folate and mean corpuscular volume (r = 0.098, = 0.326). This study shows that majority of patients with megaloblastic anaemia, diagnosed morphologically, at the University Teaching Hospital have a deficiency of vitamin B12 deficiency.