Characterization of skin blister fluids from children with Epstein-Barr virus-associated lymphoproliferative disease.

Epstein-Barr virus (EBV)-associated T- or natural killer (NK)-cell lymphoproliferative disease (LPD) is a heterogeneous group of disorders characterized by chronic proliferation of EBV-infected lymphocytes. Patients may present with severe skin manifestations, including hypersensitivity to mosquito bites (HMB) and hydroa vacciniforme (HV)-like eruption, which are characterized by blister formation and necrotic ulceration. Skin biopsy specimens show inflammatory reactions comprising EBV-infected lymphocytes. However, blister fluids have not been fully assessed in patients with this disease. Blister fluids were collected from three patients with EBV-associated LPD: two with HMB and one with HV. Immunophenotyping of blister lymphocytes and measurement of tumor necrosis factor (TNF)-α in blister fluids were performed. The patients with HMB and HV exhibited markedly increased percentages of NK and γδ T cells, respectively, in both peripheral blood and blister fluids. These NK and γδ T cells strongly expressed the activation marker human leukocyte antigen-DR and were considered to be cellular targets of EBV infections. TNF-α was highly elevated in all blister fluids. Severe local skin reactions of EBV-associated LPD may be associated with infiltrating EBV-infected lymphocytes and a high TNF-α concentration in blister fluids.