Thrombocytopenia after bone marrow transplantation caused by a recipient origin Br(a) allo-antibody: presence of mixed chimerism 3 years after the graft without hematologic relapse

• Published in: Blood 1994-01, Vol.83 (1), p.274-279
• Main Authors: Bierling, P, Pignon, J M, Kuentz, M, Mitjavila, M T, Fromont, P, Barbu, V, Goossens, M, Duedari, N, Vainchenker, W, Vernant, J P
• Format: Article
• Language: English
• Subjects: Adult; Antigens, Human Platelet - immunology; Blood Platelets - immunology; Bone Marrow Transplantation - adverse effects; Chimera - genetics; Female; Fusion Proteins, bcr-abl - genetics; Humans; Immunoglobulin G - blood; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - therapy; Polymerase Chain Reaction; Recurrence; Thrombocytopenia - etiology; Time Factors
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood.v83.1.274.274

We report a case of mild, clinically asymptomatic, immune thrombocytopenia after allogenic bone marrow transplantation (BMT) for chronic myeloid leukemia (CML) caused by the presence of a recipient-origin Br(a) antibody that recognized the donor platelets. Although the antibody titer decreased, it remained detectable more than 3 years after BMT. Chimerism studies were performed combining cytogenetics, blood cell phenotype studies, and genomic amplification of hypervariable sequences. Cytogenetic studies and molecular analysis of peripheral blood cells, purified B- and T-lymphocyte subpopulations, and bone marrow colonies showed the hematopoiesis to be of donor origin, but absorption-elution experiments with peripheral RBCs showed a small amount of recipient RBCs. The CML chimeric transcript was also detected by means of polymerase chain reaction on samples collected until day +867 post-BMT. This case shows that recipient-origin platelet alloantibodies can cause thrombocytopenia after BMT and that the persistence of small numbers of recipient cells (even leukemic) is not necessarily associated with hematologic relapse.