The clinical use of monoclonal anti-T-cell antibodies.

Monoclonal anti-T-cell antibodies are progressively replacing other T-cell markers in clinical immunology. A number of problems persist however, that urge for caution in interpreting the data issued from their in vitro use. Several antibodies directed against the same molecule may give different results according to the subject (due to genetic variants) or according to stage T-cell differentiation. The expression of antigenic determinants (epitopes may vary under the effect of drugs, positively (cimetidine, thymic hormones) or negatively (indomethacin). Lastly the correlation between phenotype and function of T-cell subsets may be very poor in the same pathological settings. In spite of these pitfalls, monoclonal anti-T-cell antibodies have proven to be very useful in several circumstances. Thus, in renal allograft recipients immunological monitoring with monoclonals helps the diagnosis of rejection in patients treated with conventional immunosuppression and permits early detection of antigenic modulation and xenosensitization in patients treated with the anti-T-cell OKT3 antibody.