[HLA-DR antigen expression on peripheral T cell subsets in pityriasis rosea Gibert, herpes zoster, and psoriasis].

Using 2 color fluorescein activated cytometric analysis, HLA-DR antigen expression in T cell subsets was studied in pityriasis rosea (PR) and compared to the results from herpes zoster (HZ) of viral origin and psoriasis (Ps). In HZ and PR, HLA-DR was significantly expressed on the T cell surface (Leu-4+ cells). Among the T cell subsets, HLA-DR antigen was predominantly expressed on suppressor/cytotoxic cells (Leu-2a+) in HZ. In contrast, it was predominantly expressed on helper cells (Leu-3a+) in PR. However, activated T cell antigen (Tac) was not significantly expressed on T cells (Leu-4+) in either HZ or in PR. This HLA-DR antigen expression of T cell subsets was depressed to the normal level in the recovery phases of HZ and PR.