T cell subsets in renal transplanted patients defined by theophylline sensitivity and monoclonal antibodies

Peripheral T cell subsets were determined in 26 patients after renal transplantation. Thirteen patients were undergoing acute rejection episodes at the time of blood sampling. Two methods were used for the determinations: the theophylline sensitivity test (THST) and the monoclonal antibodies method OKT8 and OKT4. In both rejecting and non-rejecting groups, the percentages of T suppressor lymphocytes (TS) was found to be higher by the OKT8 method than by the THST. Furthermore, no significant difference in TS percentages could be revealed by the OKT8 method between the two groups. However, with the THST the differences were significant with a mean value of 13.5 +/- 7.9 per cent in the rejecting group and 21 +/- 5.9 per cent in the non-rejecting group (p less than 0.01). The different results between the two methods could be attributed to the fact that by THST only TS cells are defined while the OKT8 conjugates also with cytotoxic T lymphocytes. The measuring of T helper cells (TH) revealed much higher percentages of TH in the rejecting group than in the non-rejecting group, 51 +/- 9.5 per cent mean value and 29 +/- 13 per cent mean value, respectively (p less than 0.05). The ratio OKT4+/OKT8+ was below one in the non-rejecting group and above 1.5 in the rejecting group. We concluded that the THST as well as OKT4+/OKT8+ ratio may be a helpful laboratory test to confirm a clinically suspected acute rejection episode.