Prospective Follow-up of Panel Reactive Antibodies From Diagnosis Until Completion of Therapy Including Allogeneic Stem Cell Transplantation Among Patients With Acute Leukemia.

Existence of panel reactive antibodies is the limiting step in both solid-organ and hematopoietic stem cell transplantation. There are hypotheses related to panel reactive antibody formation, but there is no knowledge about its formation in acute leukemia at diagnosis and during the chemotherapy period, in which there is a strong myelosuppression and immunosuppression. We aimed to determine the panel reactive antibodies positivity in acute leukemia patients at diagnosis and during the entire therapy period, including stem cell transplantation. In this single-center prospective study, we enrolled 35 patients with acute leukemia (8 with acute lymphoblastic leukemia, 27 with acute myeloid leukemia). Serum samples were obtained before induction therapy and every 3 months thereafter until the last follow-up or death, for a median of 369 days (minimum-maximum, 9-725 days). Panel reactive antibodies were defined with single-antigen bead assays on a Luminex platform. A total of 10 patients (29%) were found to have panel reactive antibodies at any time point. At diagnosis, 5 patients (14.3%) had antibodies of either class I (n = 2) or II (n = 1) or both (n = 2), and in 4 patients these persisted during median follow-up of 168 days (minimum-maximum, 9-322 days). Among the remaining 30 patients, an additional 5 (17%) developed de novo antibodies. Incidence rate of development of de novo antibodies was 5.5 per 10 000 person-days. There was no effect of transfusion load on the development of panel reactive antibodies. Differences in percentages in males versus females, blood type mismatch, and graftversus-host disease were higher in patients who had de novo antibodies after transplantation. Positivity at any time had no statistically significant effect on overall survival (P = .71). Panel reactive antibodies do not occur frequently in the acute leukemia setting despite intensive transfusions.