Survival of donor cells 25 years after intrauterine transfusion.

Persistence of donor leukocytes in the circulation of recipients of intrauterine transfusion (IUT) has been observed up to 5 years after birth. The aim of this study was to determine whether transfusions with nonirradiated, nonleukocyte-depleted donor blood during the fetal period resulted in long-term immunomodulation of the recipient. Twenty-four surviving IUT recipients between 1966 and 1976 were tested for autoimmune disease and autoantibodies at follow-up. Ten had sex-mismatched donors and were therefore informative for chimerism studies using fluorescence in situ hybridization (FISH). Seven female recipients could be tested for chimerism using a Y- chromosome-specific polymerase chain reaction (PCR) because they received at least 1 IUT from a male donor. Nine recipients could be studied for cytotoxic T-lymphocyte precursor (CTLp) and helper T-lymphocyte precursor (HTLp) frequencies because the original donors were available for testing. All surviving IUT recipients were in good health at the time of the examination, and routine laboratory testing revealed no abnormalities. None of the IUT recipients were chimeric as determined by FISH analysis, but Y-chromosome-specific sequences were detected by PCR in 6 of the 7 women. However, the CTLp and HTLp frequencies of the IUT recipients against the donors were comparable to those of the controls. The current study provides evidence that IUT can result in the persistence of donor cells in the recipient for a period longer than 20 years but that it is not associated with immunotolerance or with signs of chronic antigenic stimulation. (Blood. 2000;95:2709-2714)