Immune Complexes and Lymphocyte Subset in Secondary Stage Pityriasis Rosea#

Abstract

Circulating immune complexes (CIC), percentages of lymphocyte subsets, serum immunoglobulins (IgG, M, A), serum complements (C3, C4) and tissue immunoreactants (IgG, M, A, C3, Clq, properdin and fibrinogen) were measured in thirty‐one patients with secondary stage pityriasis rosea (PR) and in forty‐five healthy controls. In these patients, no significant amount of CIC and tissue immunoreactants were detected. Decreased OKT4/OKT8 ratio resulting from the decreased OKT4‐positive (helper/inducer) cells and the increased OKT8‐positive (suppressor/cytotoxic) cells was noted in the patients as compared with the controls (p<0.001). In addition, an elevation of IgM and a decrease of C3 in sera were also noted. The role of the immune mechanism in the pathogenesis of PR and the possible causal agents are discussed.