HLA and lymphocyte histamine sensitivity in mastocytosis.

HLA-ABC and DR typing was performed on 50 patients with mastocytosis. Lymphocyte stimulation with concanavalin A has earlier been performed in 22 of these patients. No phenotypic aberrations were detected in the patient group. 8 patients had the HLA-B12 phenotype. Lymphocytes from the HLA-B12 phenotype stimulated with a lymphocyte mitogen have earlier been shown to react with decreased inhibitory effect to histamine. 2 patients in this study had the HLA-B12 phenotype and systemic mastocytosis with high histamine turnover, but these patients reacted with a low mitogen response of the lymphocytes.