The effect of hyposensitization on alternaria-induced lymphocyte blastogenesis

Twenty-one atopic children were treated with alternaria hyposensitization therapy. Leukocytes from these children were cultured with and without alternaria and phytohemagglutinin prior to treatment, and after 6 and 12 months of treatment. Patients demonstrating positive immediate cutaneous hypersensitivity showed significant lymphocyte transformation prior to hyposensitization whereas the skin test-negative patients did not. The skin test-negative patients developed significant lymphocyte transformation after 6 months of hyposensitization. Twelve months after the initiation of therapy both skin test-negative and skin test-positive patients showed a decreased lymphocyte reactivity, and there was no longer any significant change in the concomitant phytohemagglutinin responses indicating that hyposensitization had a specific effect on alternaria-induced in vitro lymphocyte reactivity. Plasma factors were found to have modulating effects on the lymphocyte reactivity of hyposensitized patients.