Clinical significance of specific IgG and IgE antibodies to toluene diisocyanate (TDI)-human-serum albumin (HSA) conjugate in TDI-induced occupational asthma

Abstract

Background and Objective : TDI is known to be the most prevalent cause of occupational asthma (OA) in Korea. However, the pathogenesis of TDI-induced occupational asthma still remains to be further clarified. So, we evaluated clinical significance of serum specific IgG and IgE antibodies to TDI-HSA conjugate in TDI-induced occupational asthma. Subjects and Methods : Serum specific IgG and IgE antibodies to TDI-HSA conjugate were measured by enzyme linked immunosorbent assay. Serum was collected from 50 TDI- induced OA patients (classified as group Ⅰ), and was compared with that from 13 asthmatic subjects with negative TDI-bronchoprovocation test (BPT, group Ⅱ), allergic asthmatics (group Ⅲ), and unexposed healthy controls (group Ⅳ). Results : The prevalence of specific IgG was significantly higher in group Ⅰ than in group Ⅱ (p=0.01) or group Ⅲ (p<0.01). No significant difference was noted between group Ⅱ and group Ⅲ (p>0.05). However, the prevalence of specific IgE was not different between group Ⅰ and group Ⅱ (p>0.05) or group Ⅱ and group Ⅲ (p>0.05). There was no significant difference in prevalence of specific IgG according to the asthmatic response during TDI bronchoprovocation test (p>0.05). No statistical significance was noted between specific IgG and IgE antibodies in group Ⅰ subjects (p>0.05). Conclusion : These findings demonstrate that presence of specific IgG to TDI-HSA conjugate is closely related to TDI-BPT results and it may contribute to the development of TDI-induced asthma.