Atezolizumab?induced pure red cell aplasia

A 45-year-old woman underwent a bone marrow biopsy for evaluation of persistent, severe transfusion-dependent normocytic anaemia, beginning approximately two months following initiation olaparib and atezolizumab therapy metastatic BRCA1-mutated breast carcinoma. The anaemia had not improved despite discontinuation three months. blood count on the day showed: haemoglobin concentration 82 g/l (post-transfusion), mean cell volume (MCV) 85 fl, neutrophils 1.53 × 109/l, platelets 167 109/l reticulocytes 2 (0.1%). aspirate trephine specimen were normocellular, but exhibited very striking reduction erythropoiesis (top images). Proerythroblasts comprised 0.4% all nucleated cells. There was no significant dysplasia. Trephine sections stained glycophorin (bottom right) confirmed virtual absence erythropoietic activity. CD3 staining left) demonstrated an increased number T lymphocytes, interstitially in small aggregates. Serology human immunodeficiency virus (HIV) 1 serology polymerase chain reaction (PCR) parvovirus B19 negative. Serum vitamin B12 (659 pmol/l) folate (>45 nmol/l) normal. Cytogenetic analysis showed normal karyotype. Flow cytometry 85% cells with loss pan-T markers equal CD4+ CD8+ cells, 7% lymphocytes double negative (CD4?/CD8?) ?/? type.