Altered immunoregulatory function in long-term renal allograft recipients.

In order to determine immunoregulatory lymphocyte subsets in patients with long surviving renal allografts, a study utilising functionally characterised monoclonal antibodies with analysis by flow cytometry using a Fluorescence Activated Cell Sorter was carried out. Cells from 35 patients with allograft survival from one to 15 years were analysed with monoclonal antibodies for the following markers: inducer-helper, cytotoxic-suppressor, monocytes, Ia, IgG and IgM. Control groups consisted of long-term dialysis patients and a group of normal individuals. The results show a strikingly significant difference between the long-term allograft recipients and the control population in terms of the inversion of the normal inducer-helper to cytotoxic-suppressor ratio. Additionally, there were significant differences in the number of Ia+ cells in long-term transplant patients and dialysis patients compared with normals. No impressive differences were found in the numbers of Ig bearing cells. Thus the long-term allograft state is a clear example of an overabundance of cellular suppression and may explain many of the general phenomena seen in surviving recipients.