Abstract
Vitamin B12 deficiency is a worldwide public health issue, with its prevalence high in the developing countries. It is a micronutrient synthesized by microorganisms and obtained through diet and its deficiency can lead to megaloblastic anaemia and neurological deficits. The elderly are more prone to it. Pernicious anaemia is a prevalent cause of megaloblastic anaemia, which is associated with autoimmune destruction of parietal cells and intrinsic factor deficiency by APCA and AIFA antibodies. These antibodies can cause mucosal damage and hinder vitamin B12 absorption. The present prospective observational study included 166 patients with severe vitamin B12 deficiency (defined by Vitamin B12 levels ≤ 150 pg/mL) who were treated at a tertiary care centre in western Rajasthan. Expression of AIFA and APCA were assessed and their association with different parameters were evaluated. The present study didnot find any significant association between APCA and AIFA impressions, indicating that the absence or presence of one antibody did not strongly predict the presence or absence of the other antibody. This suggests that these autoantibodies may have distinct roles or mechanisms in PA and further research is needed to understand their relationship.