CIRCADIAN VARIATIONS AND PREDNISOLONE-INDUCED ALTERATIONS OF CIRCULATING LYMPHOCYTE SUBSETS IN MAN

We determined the circadian variations and prednisolone (PSL)-induced alterations of circulating lymphocyte subsets in 10 healthy adults by two-color how cytometry using monoclonal antibodies to various lymphoc yte subsets in order to collect fundamental data for monitoring of the subsets in clinical practice. This study first examined the changes o f CD5+ B cells, gamma delta+ or gamma delta T cells, activated (HLA-DR +) CD4+ or CD8+ cells, CD11b+ or CD11b-CD8+ cells, and natural killer (NK) cell subsets (CD16+CD57-, CD16+CD57+, CD16-CD57+), in addition to other subsets described before. Compared with the base line values ob tained at 9:00 (AM) on day 1, lymphocytes, total B cells, CD5+ B cells , total T cells, gamma delta T cells, CD4+ cells, activated CD4+ cells , CD45RA-CD4+ cells, and activated CD8+ cells were significantly incre ased at 20:00 (PM). However, the numbers of CD45RA+CD4+ cells, CD11bor CD11b-CD8+ cells and three NK cell subsets did not show significant circadian variations. After oral PSL (30 mg), which was given at 7:00 (AM) on day 2, lymphocytes and almost all lymphocyte subsets, except for CD16+CD57- cells, were significantly decreased; these changes reco vered between 13 and 26 hours after PSL administration. The circadian variations and PSL-induced alterations of lymphocyte subsets were rela tively comparable, but PSL administration cause a decrease in a wider range of lymphocyte subsets including relatively forticosteroid-resist ant subsets such as CD45RA+CD4+ cells, CD8+ cell and NK cell subsets. Thus, these alterations of lymphocyte subsets should be taken into acc ount in the evaluation of patients with immunologic abnormalities, esp ecially those receiving PSL treatment.