Prognostic value of T lymphocyte subset ratios for renal transplant survival in patients on different immunosuppressive regimens

Previously we reported that the pre-treatment and pre-injection OKT4/OKT8 ratio can be used to predict renal allograft survival. Patients on azathioprine (Aza) and low-dose steroids (St) with a pretransplant ratio ≤ 1.6 exhibited a 6-month grafts survival of 33% compared with 79% for those with ratio > 1.6 (P = 0.02). Furthermore, 100% of the rejection episodes treated with high doses of prednisone in patients with a prerejection ratio ≤ 1.6 were irreversible in comparison with only 10% for patients with a ratio > 1.6 (P <0.001). In the present study, we investigated the prognostic value of the OKT4/OKT8 ratio for patients who received rabbit antithymocyte globulin (RATG) as anti-rejection therapy or cyclosporin A (CsA) as basic immunosuppressive therapy. No correlation was found between the pre-transplant OKT4/OKT8 ratio and 6-month graft survival for either treatment group because of an improved graft survival among patients with a pre-transplant ratio ≤ 1.6 (78% for patients who received RATG and 85% for CsA-treated patients). For Aza-treated patients with an OKT4/OKT8 ratio ≤ 1.6 at the time of rejection, rejection episodes that were treated with RATG were reversible in 78% of the cases, whereas among CsA-treated patients rejection epidoses treated with high doses of prednisone were reversible in 72% of the cases. No significant differences in graft survival or reversibility of rejection episodes between patients with a pre-transplant or pre-rejection of OKT4/OKT8 ratio > 1.6 were found. Furthermore, in both the CsA and the Aza-treated patients (with or without RATG), the OKT4/OKT8 ratio had decreased significantly 3 months after transplantation. This decrease was associated with cytomegalovirus infections rather than the type of immunosuppressive therapy.