Peripheral blood lymphocyte populations and phagocytic functions in patients with active alopecia areata

The proportions and absolute number of peripheral blood CD3+, CD4+, CD8+ and CD16+ and CD26+ lymphocytes, large granular lymphocytes, B lymphocytes and phagocytic ability (ingestion and intracellular killing) were determined in 29 patients with active alopecia areata (AA), 14 of them being free of therapy and 15 receiving topical steroid therapy, as well as in 30 healthy individuals. The percentage of CD8+ cells was decreased and the CD4/CD8 ratio increased, while monocyte microbicidal capacity was decreased in the AA patients compared to the controls. The percentage of CD8+ cells remained decreased in patients free of therapy but returned to normal in those on therapy, while the CD4/CD8 ratio remained increased in both patient subgroups. The percentage of CD26+ cells was increased in patients free of therapy. Monocyte ingestion ability was decreased in patients on therapy compared to the healthy controls. Monocyte microbicidal capacity was normal in patient free of therapy, while in those on therapy it was decreased compared both to healthy controls and to patients free of therapy. The reported alterations in proportions of peripheral blood lymphocyte populations support the hypothesis of autoimmune origin of AA. Decreased monocyte phagocytic functions probably were induced by steroid therapy rather than by the disease per se.