A whistleblower direct antiglobulin test in chronic kidney disease: An interesting case of occult autoimmune hemolytic anemia in an undiagnosed lymphoma with pure red cell aplasia.

A 67-year-old male, presented with urosepsis, severe anemia, advancing azotemia requiring blood transfusion. Patient grouped as O RhD positive. Antibody screening was pan-positive (4+). Similar strong pan-positivity seen on antibody identification with extended cell panel. DAT was 4+ positive for IgG and negative for complement C3. Repeated identification with eluate also showed pan-positive (4+) reaction. Serum haptoglobin markedly reduced. Bone marrow aspirate suggested pure red cell aplasia with suspicion of parvovirus-related changes. Bone marrow biopsy suggested T-cell lymphoproliferative disorder. Immunophenotyping elucidated a suspicious clone of CD7-negative T-cells with CD4 restriction. Histopathological examination revealed angioimmunoblastic T-cell lymphoma (AITL) with bystander Epstein-Barr virus-driven large B-cells. Owing to rarity and nonspecific symptoms, diagnosis of AITL is often challenging. Antibody screen acted as a whistleblower for an undiagnosed aggressive lymphoma. Thus, it will be prudent to look beyond the obvious in complex cases, and a detailed workup will help put together all parts of the jigsaw puzzle.