Epidermodysplasia Verruciformis Accompanied by Large Granular Lymphocytosis: Report of a Case and Immunological Studies

A 34-year-old man with epidermodysplasia verruciformis showed increased natural killer cell activity in his peripheral blood cells, which was found to be due to abnormal expansion of large granular lymphocytes Surface marker analysis of LGL in a two-color immunofluorescence test demonstrated that all LGL subsets, Leu7+11-, Leu-7+11+, and Leu-7-11+, were increased. In contrast, his peripheral blood mononuclear cells showed a remarkable decrease in response to T cell mitogens, which could not be restored by depletion of the LGL subpopulation from the mononuclear cells. Immunohistologic studies for dermal distribution of LGL showed numerous Leu-7+ cells but no Leu-11+ cells at the sites of delayed hypersensitivity reaction or interferon β- or interferon γ-injected sites. These findings suggest that the elevated NK cell activity in this patient with epidermodysplasia verruciformis was caused by overall expansion of normal LGL subpopulations, but that the decreased T-cell mitogenic response represented a primary T-cell defect rather than a direct suppression by increased NK cells. It is noteworthy that despite this extraordinary increase of all LGL subpopulations in the blood, Leu-11+ NK cells never appeared in the skin.