Two cases of vitamin B12 deficiency in patients with beta-thalassemia trait: lessons in diagnosis

Abstract

Abstract Background Coexisting pathologies is not a new phenomenon and can cause diagnostic difficulties when they overshadow one another. They may alter the cytomorphology of cells and the machine readings to an extent that the actual diagnosis is missed. One such scenario is created by coexisting megaloblastic anemia and beta-thalassemia trait where the RBC indices and the hemoglobin chromatogram findings conform to neither of the two. Case presentation We present two cases of anemia presenting with normocytic normochromic indices, increased red cell distribution width (RDW), elevated HbA2 levels and moderately high HbF levels in both of them and an additional low HbA1c in case 2. Upon evaluation of peripheral smear and biochemical tests, a non-immune hemolytic component was also identified with deficient Vit B12 levels in case 1 and highly elevated levels post-supplementation in case 2. Conclusions Taking together the peripheral smear, erythrogram, chromatogram and biochemical findings, it was deduced that the alterations were caused by coexisting beta-thalassemia trait and megaloblastic anemia. Vit B12 deficiency was the cause behind hemolysis owing to intramedullary destruction of abnormal precursors. Upon supplementation in case 2, the immediate reticulocyte response was the reason behind spuriously low HbA1c.

Keywords

• Beta-thalassemia trait
• Megaloblastic anemia
• Hemolysis
• HbF