Elimination of alloantibodies by immunoablative high-dose cyclophosphamide
R A Brodsky1, A K Fuller, L E Ratner
1Johns Hopkins Oncology Center, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland 21231, USA. rbrodsky@jhmi.edu
Background:
Alloimmunization is a major problem for patients being considered for solid organ transplantation and in patients who require blood transfusion support. We previously demonstrated that high-dose cyclophosphamide (200 mg/kg) without hematopoietic stem cell transplantation leads to durable complete remissions in aplastic anemia and other autoimmune disorders. We now examine the ability of high-dose cyclophosphamide to eliminate alloreactivity.
Methods:
IgG-specific antibodies to HLA class I were assayed using enzyme-linked immunosorbent assays in 18 consecutive patients with severe aplastic anemia before and after treatment with high-dose cyclophosphamide.
Results:
Anti-HLA antibodies were detected before or shortly after therapy in 5 of the 18 patients studied. Complete remission of aplastic anemia was achieved in four of these five patients. High-dose cyclophosphamide markedly reduced anti-HLA antibody titers in these four patients; they were completely eradicated in three patients. Only one patient did not achieve significant reduction in the alloantibody titer after high-dose cyclophosphamide.
Conclusions:
High-dose cyclophosphamide without stem cell transplantation can eradicate HLA-specific alloantibody.
