EFFECTS OF SINGLE-DOSE COMPARED WITH 3 DAYS PREDNISOLONE TREATMENT OFHEALTHY-VOLUNTEERS - CONTRASTING EFFECTS ON CIRCULATING LYMPHOCYTE SUBSETS

Aims-To investigate the effects of longer term corticosteroid treatmen t on circulating lymphocyte subsets. Methods-Prednisolone (20 mg daily ) was given to 12 healthy volunteers in a single morning dose for thre e days. Circulating lymphocyte subsets were measured by flow cytometry after whole blood lysis. Results-Seven hours after the first dose of prednisolone there was a significant fall in absolute numbers of lymph ocytes, T cells, CD4+ and CD8+ cells, and B cells. The percentage of T cells fell significantly, due to a fall in percentage of CD4+ cells. In contrast to the seven hour findings, at 72 hours there was a signif icant rise in absolute numbers of lymphocytes, T cells, CD4+, CD8+, an d B cells. This trend was already apparent by 24 hours. The percentage of CD4+ cells was significantly raised at 72 hours, while that of CD8 + cells had fallen significantly. The percentage of natural killer cel ls had fallen at 72 hours; that of B cells remained increased at 72 ho urs. Conclusions-These findings show that corticosteroid treatment cau ses significant changes in lymphocyte subsets, and that such changes m ust be considered when designing studies of lymphocyte subsets during illness.