Megaloblastic anaemia: prevalence and causative factors.

Abstract

<p><strong>Background</strong>: Megaloblastic anaemia is not uncommon inIndia, but data are insufficient regarding its prevalence, andcausative and precipitating factors. We did a prospective studyto document such data for patients of megaloblastic anaemia.</p><p><strong>Methods</strong>: All patients presenting to our hospital over a periodof 6 months with a haemoglobin <10 g/dl and/or meancorpuscular volume >95 fL and blood film findings consistentwith megaloblastosis were included in the study. Demographicdata, diet, drug intake, previous blood transfusion and presentingsymptoms were recorded. Clinical findings were obtained frommedical records of patients. Complete blood counts, blood filmexamination, reticulocyte count and cobalamin and folate assayswere done. Results of liver function tests and bone marrow slideswere available for review.</p><p><strong>Results:</strong> Megaloblastic anaemiawas diagnosed in 175 patientswith anaemia. Assays were done on 120 patients (55 were lostto follow up) and results showed cobalamin deficiency in 78patients (65%), combined cobalamin and folate deficiency in 20patients (12%) and pure folate deficiency in 8 patients (6%).Fifteen per cent of patients had normal or high values of bothvitamins, having received blood or haematinics before thediagnosis was established. The peak incidence of megaloblasticanaemia was in the age group of 1030 years (48%), withfemale preponderance (71%). The predominant symptomswere fatigue, anorexia and gastritis, low grade fever, shortness ofbreath, palpitations and mild jaundice. Twenty-five per cent ofpatients were on acid-suppressing medication and 15% hadprevious transfusion for anaemia. Eighty-seven per cent ofpatients with cobalamin deficiency and 75% with folate deficiencywere lactovegetarians. In the combined deficiency cohort, 71%were vegetarians and 29% were occasional non-vegetarians.Physical findings were pallor (85%), glossitis (29%), mild icterus(25%) and hyperpigmentation (18%).Abnormal haematological findings were mean corpuscularvolume 77123 fL (9 patients had iron deficiency), red celldistribution width 16%44%, pancytopenia in 62% of patients,reticulocyte count >2% in 42% of patients and typicalmegaloblastic blood films in all patients. Bone marrow smearsavailable in 22 patients showed moderate-to-severemegaloblastosis. Thirty-two per cent of patients in whom liverfunction tests were done showed indirect bilirubinaemia withnormal enzymes.</p><p><strong>Conclusion:</strong> Megaloblastic anaemia was diagnosed fromcomplete blood counts, red cell indices, blood film examinationand assays of the two vitamins. Bone marrow examination wasnot essential for diagnosis. Cobalamin deficiency was the majorcause of megaloblastosis. Aetiological factors were a diet poor incobalamin or folate, increased requirements during the growthperiod and pregnancy, and the use of acid-suppressing medication.Physicians managing these patients need to be aware of the timingof blood sampling for assays, that haematinics and transfusionsprovide only short term benefits, and that long term follow upand diet counselling is crucial.</p>