ABSENCE OF IRREVERSIBLE REJECTION IN THE PRESENCE OF WARM ANTI-DONOR-HLA CLASS-I CYTOTOXIC IGG ANTIBODY

Since the initial presentation by Kissmeyer-Nielsen and colleagues [19 66] and later by Patel and Terasaki [1969], it has been accepted that renal transplantation should not be performed in the presence of cytot oxic alloreactive antibodies of the IgG fraction performed at room tem perature against HLA Class I [Braun 1989] antigens. Such antibodies ar e feared to induce hyper-acute or accelerated rejection because of the presence of HLA Class I antigens on kidney cells. For this reason, th e microlymphocytotoxicity crossmatch (XM test: recipient serum reacted against donor lymphocytes as surrogate for HLA antigens) is now unive rsally used before transplantation [Ting 1983]. A positive XM performe d against the recipient T lymphocyte at room temperature after treatme nt of recipient serum with dithiothreitol (DTT), an agent that removes immunoglobulin M, denotes the presence of cytotoxic alloreactive IgG antibodies against the potential donor HLA class I antigen. Herein, we present the case of a patient who developed positive XM test of the I gG isotype against HLA Class I of the donor antigens performed at room temperature seven days after she received a kidney allograft from her daughter. Although the development of a positive XM was associated cl inically with acute rejection, the patient responded remarkably well t o anti-rejection therapy and maintained excellent graft function there after. Thus, strategies to identify the role played by the different I ge isotypes determined against HLA Class I antigens and their relation to irreversible rejection are needed to differentiate between those p otential kidney recipients who may benefit from kidney transplantation in the presence of innocent warm Ige subclass antibodies reactive aga inst HLA Class I antigens and those patients who may not.