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.
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.
Bierling
P
P
Centre de Transfusion, Hôpital Henri Mondor, Creteil, France.
Pignon
J M
JM
Kuentz
M
M
Mitjavila
M T
MT
Fromont
P
P
Barbu
V
V
Goossens
M
M
Duedari
N
N
Vainchenker
W
W
Vernant
J P
JP
D000328:Adult; D016824:Antigens, Human Platelet / Q000276:immunology*; D001792:Blood Platelets / Q000276:immunology*; D016026:Bone Marrow Transplantation / Q000009:adverse effects*; D002678:Chimera / Q000235:genetics*; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000628:therapy*; D016133:Polymerase Chain Reaction; D012008:Recurrence; D013921:Thrombocytopenia / Q000209:etiology*; D013997:Time Factors
C055973:5b alloantigen, human; D016824:Antigens, Human Platelet; D007074:Immunoglobulin G; D016044:Fusion Proteins, bcr-abl