OKT4/8 ratio in the blood and in the graft during episodes of human renal allograft rejection.

We have analyzed the frequency of T helper (Th) and T suppressor/killer (Ts/k) lymphocytes in the blood and in the renal allograft during episodes of rejection and during quiescence. Monoclonal OKT4 and OKT8 antibodies were used to mark the Th and Ts/k cells, respectively. Density centrifugation-separated mononuclear leukocytes and FACS IV cell sorter or the Staphylococcus aureus rosette assay were used to determine the ratio in the blood, with concordant results. Fine needle aspiration biopsy (FNAB) and the Staph. assay were used to demonstrate the lymphocyte subtypes in the graft. The mean OKT4/8 ratio in the blood was significantly lower in the transplant recipients than in healthy controls (1.1 +/- 0.7 vs 1.8 +/- 0.2, respectively, P = 0.000). The individual variation was, however, high and no correlation between the OKT4/8 ratio in the blood and the inflammatory episodes in situ was observed. During 19 of the 25 episodes of inflammation, the dominant lymphocyte subtype in the graft was the Ts/k cell. In the remaining six cases it was the Th cell. All rejection episodes of the former type were reversible, in the latter type, four out of six were irreversible.