Papular polymorphic light eruption: an immunoperoxidase study using monoclonal antibodies

Abstract

Biopsy specimens of papules taken from 8 patients with polymorphic light eruption were examined by immunoperoxidase techniques employing monoclonal antibodies. In each case, most infiltrating mononuclear cells were T cells. The majority of T cells were T8-positive (cytotoxic/suppressor) in 4 cases and T4-positive(helper/inducer) in 2. In 2 cases, approximately equal numbers of both T cell subsets were present. In only 3 cases were rare B cells identified by their reactivity with anti-IgM antibody. MI-positive mononuclear cells (macrophages) represented < 5% of cells infiltrating the dermis. In 5 subjects, anti-T6 antibody stained increased numbers of dermal mononuclear cells considered to be Langerhans/indeterminate cells. The pathogenesis of papular polymorphic light eruption may involve injury to upper dermal venules mediated by T cells and Langerhans/indeterminate cells.