Pure red cell aplasia and warm autoimmune haemolytic anaemia induced by programmed cell death protein 1 (PD1) inhibitor therapy

Abstract

A 79-year-old female with a history of resected margin-positive melanoma on 6 months of nivolumab therapy presented to emergency with symptomatic anaemia (Hb 72). There was no bleeding or relevant medical history. Her FBC was otherwise normal aside from reticulocytopenia (6.2x109) with normal haematinics. There was evidence of haemolysis with undetectable haptoglobin, elevated LDH and strong positive direct antiglobulin test (DAT) for IgG/C3d with negative elution. Group and screen showed no alloantibodies with adequate increment and rapid reduction in haemoglobin post-transfusion.