RESUMEN
To evaluate the presence of intrinsic factor antibody in vitamin B12 deficient patients. Cross-sectional, observational study. Fauji Foundation Hospital, Foundation University Medical College and Armed Forces Institute of Pathology, Rawalpindi, from January 2011 to June 2012. A total of 120 patients of megaloblastic anaemia were selected on the basis of low serum vitamin B12 level. The intrinsic factor antibody tests were performed by ELISA method. The patients were considered positive or negative on the basis of presence or absence of intrinsic factor antibody respectively. The data was analyzed by using SPSS version 14. Pernicious anaemia with intrinsic factor deficiency was found in 13.3% in 120 vitamin B12 deficient patients. The mean age of patients of pernicious anaemia was 41.5 years, with a male to female ratio of 1:2.5. It was relatively more common in older age [17% in age more than 60 years] as compared to other age groups. Frequency of pernicious anaemia in megaloblastic anaemia was 13.3%. The male to female ratio was 1:2.5 and it was relatively more common in age group of more than 60 years