Ratios of T lymphocyte subpopulations predict survival of cadaveric renal allografts in adult patients on low dose corticosteroid therapy.

Peripheral blood T lymphocyte subpopulations were monitored in 45 consecutive adult recipients of cadaveric renal allografts by using monoclonal antibodies and flow cytometrie. All patients were treated with low dose corticosteroids and azathioprine. In 37 patients pre-transplant OKT4/OKT8 ratios were available. Six of 26 patients (23%) with pre-transplant OKT4/OKT8 ratios greater than 1.6 and seven of 11 patients (64%) with pre-transplant OKT4/OKT8 ratio less than or equal to 1.6 lost their graft due to rejection within 6 months. The difference in transplant survival between patients with pre-transplant OKT4/OKT8 ratios greater than 1.6 and less than or equal to 1.6i is just significant (P = 0 . 049 Fishers test). No correlation was found between post-transplant values of individual lymphocyte subpopulations or OKT4/OKT8 ratios and the incidence of subsequent rejection episodes. Forty out of 45 patients suffered one or more rejection episodes which were treated by raising the dosage of prednisone. In 24 of these patients the rejection episode was reversed, leading to a transplant survival of at least 6 months. In these 24 patients the OKT4/OKT8 ratio was greater than 1.6 for at least 3 days before the institution of any rejection treatments. Sixteen patients lost their graft due to rejection within 6 months after transplantation. In 11 of these 16 patients OKT4/OKT8 ratios less than or equal to 1.6 preceded the institution of all rejection treatments for at least 3 days, while in three patients the OKT4/OKT8 ratio was greater than 1.6 before the first rejection episode but this ratio was less than or equal to 1.6 before subsequent rejection episodes. Thus, OKT4/OKT8 ratios greater than 1.i6 correlated with reversible rejection episodes and OKT4/OKT8 ratios less than or equal to 1.6 correlated with irreversible rejection (P less than 0 . 001).