Primary Sjögren's syndrome and psoriasis vulgaris in a case of OKT4 epitope deficiency.

We report a 29-year-old female OKT4 epitope deficiency patient with primary Sjögren's syndrome and psoriasis vulgaris. Immunological investigations during the prolonged clinical course of her herpes zoster revealed that she has OKT4 epitope deficiency and primary Sjögren's syndrome. She had been treated for psoriasis vulgaris for 17 years without systemic immunosuppressive therapy. Flow cytometric study revealed that her OKT4 deficiency is heterogeneous and excluded interference with the OKT4 epitope by anti OKT4 autoantibodies. The rare coexistence of primary Sjögren's syndrome and psoriasis implicates an immune disturbance due to an unusual phenotype of CD4.