SUPPRESSION OF HLA-SPECIFIC ALLOANTIBODIES BY HIGH-DOSE INTRAVENOUS IMMUNOGLOBULINS (IVIG) - A POTENTIAL TOOL FOR TRANSPLANTATION OF IMMUNIZED PATIENTS

Renal transplantation in patients presenting end-stage renal failure c an be hampered by the presence of alloantibodies against HLA antigens. In 4 out of 5 patients with HLA-specific alloantibodies waiting for a renal allograft, treatment with high-dose i.v. Ig resulted in a prolo nged suppression (over 3 months) of most of the panel-reactive anti-HL A antibodies (PRA). Intravenous polyclonal human Ig (IVIg) and F(ab')2 fragments from IVIg inhibited the binding of patients' plasma and IgG fractions to peripheral blood lymphocytes from normal donors as well as their cytotoxicity, suggesting that the in vivo effect of IVIg was mediated by the presence, in the IVIg preparation, of anti-idiotypes d irected against idiotypes borne on the anti-HLA antibodies. Thus, trea tment with IVIg can be a valuable tool toward the transplantation of i mmunized patients.