ANTIGEN-SPECIFIC STIMULATION OF HISTAMINE-RELEASING FACTORS IN DIISOCYANATE-INDUCED OCCUPATIONAL ASTHMA

Diisocyanate-induced asthma differs from occupational asthma (OA) caus ed by protein allergens in that specific IgE antibody responses are ra rely identified. To investigate the immunopathogenesis of diisocyanate asthma, diisocyanate-exposed workers were evaluated for in vitro prod uction of antigen-specific mononuclear cell-derived histamine releasin g factor (HRF). The mean HRF response to diisocyanate-HSA antigens was significantly greater in patients with OA than in diisocyanate-expose d asymptomatic subjects (p < 0.05). No association was found between H RF and diisocyanate-specific antibodies. Analysis of HRF production by subpopulations of peripheral blood mononuclear cells (PBMC) showed th at lymphocytes and adherent cells were major sources of both spontaneo us and antigen-stimulated HRF. The results suggest that antigen-specif ic HRF produced by PBMCs ate an important biomarker for diisocyanate-i nduced asthma. This is the first report of hapten-specific stimulation of PBMCs resulting in HRF production.