[Temporary changes and permanent changes in the erythrocyte blood-group antigens in malignant hemopathies]

Samples of peripheral blood were taken from 11 patients (blood group A, B and O), suffering from acute myeloblastic leukemia (AML), acute lymphoblastic leukemia (ALL), myelodysplastic syndrome (MDS), before and after chemotherapy, compared to normal control samples. The RBC's typing was done by standard agglutination technique (with conventional human and murine anti-sera) and flow cytometry. While using different reagent dilutions, a lower expression of the A or B antigen was noticed in all patients, even if direct typing of the RBC's revealed an apparently normal pattern. The most important depletion of antigenic expression was found to correspond to the highest concentration of myeloblasts in the bone marrow, with hypoplastic erythrocytic series. The modified H reactivity, detected at admission, was still present after complete remission, as an expression of the residual disease. Studies of the H expression could eventually become a parameter of evaluating the moment of relapse of the myeloproliferative disease.