Specific immunoglobulin E and immunoglobulin G antibodies to toluene diisocyanate‐human serum albumin conjugate: useful markers for predicting long‐term prognosis in toluene diisocyanate‐induced asthma

Abstract

SummaryBackground Our previous study reported that more than 50% of toluene diisocyanate (TDI)-induced asthma patients had persistent asthmatic symptoms even after complete avoidance. Although specific IgE (sIgE) has been detected in a portion of patients with TDI-asthma, a recent investigation suggests that the presence of serum specific IgG (sIgG), not sIgE, is more closely associated with positive bronchoprovocation test (BPT) results. Objective To evaluate the possible role of sIgE and sIgG in predicting long-term prognosis of TDIasthma. Materials and methods Forty-one TDI-asthma patients whose diagnosis was confirmed by TDI-BPT, and 20 unexposed healthy controls were enrolled. Both sIgE and sIgG to TDI-human serum albumin (HSA) conjugate were detected by ELISA. All patients with persistent asthmatic symptoms took anti-asthmatic medications during the follow-up period (mean: 67.5 months) and were instructed to avoid exposure to TDI. Airway hyper-responsiveness to methacholine (AHM) was monitored every year during the study period. The patients were classified into three groups according to changing patterns of AHM and asthmatic symptoms as follows: group I, no improvement with persistent asthmatic symptoms (n 12); group II, partial improvement with persistent asthmatic symptoms (n 13); group III, in remission (n 16). Results Favourable prognosis was associated with a mild degree of AHM at initial diagnosis (P < 0.05). Although there were no significant differences in the prevalence of sIgE antibody to TDI-HSA conjugate among the three groups (P > 0.05), prevalence of sIgG in group I tended to be higher than in group II (0.05 < P < 0.1). However, the levels of sIgG were significantly higher in group I than in group II (P 0.05), whereas levels of sIgE were significantly higher in group II than in group I (P 0.014). No significant differences were noted in exposure duration, sex, age, atopic status, and total IgE level among the three groups (P > 0.05). Conclusion This study confirmed that a favourable outcome is related to a mild degree of AHM and to low levels of sIgG to predict persistent asthmatic symptoms, it also suggested that the presence of high serum-specific IgE at initial diagnosis may represent a better prognosis.

The HLA DRB1*1501-DQB1*0602-DPB1*0501 Haplotype Is a Risk Factor for Toluene Diisocyanate-Induced Occupational Asthma

“…Isocyanate-specific IgE and IgG antibodies have been detected in some sensitive individuals [10, 11], and activated CD4+ T cells and increased levels of cytokines produced by Th2 cells have been reported [12, 13]. Furthermore, the involvement of autoimmune reactions to isocyanate-airway epithelial cell protein conjugates has been proposed [14, 15].…”

Serum ferritin and transferrin levels as serologic markers of methylene diphenyl diisocyanate–induced occupational asthma

“…In the case of toluene diisocyanate-induced occupational asthma (TDI-OA), specific IgE and IgG antibodies to toluene diisocyanate (TDI)-human serum albumin conjugate were found to be good diagnostic tools. [3][4][5] In addition, serum-specific IgG to cytokeratin 19 was suggested as a possible serologic marker of TDI-OA, but the sensitivity of these 2 parameters was too low to be applied. [3][4][5][6] In methylene diisocyanate-induced occupational asthma (MDI-OA), although the level of serum specific IgE and IgG antibodies was found to be increased in some patients, 7 it was not high enough to be used for diagnostic purposes.…”

“…[3][4][5] In addition, serum-specific IgG to cytokeratin 19 was suggested as a possible serologic marker of TDI-OA, but the sensitivity of these 2 parameters was too low to be applied. [3][4][5][6] In methylene diisocyanate-induced occupational asthma (MDI-OA), although the level of serum specific IgE and IgG antibodies was found to be increased in some patients, 7 it was not high enough to be used for diagnostic purposes. Considering that permanent impairment of lung function was reported in long-term follow-up studies of isocyanate-induced asthma, 8 developing relevant serologic markers to identify susceptible subjects among exposed workers is essential.…”

Determination of chemical-specific IgGs in serum by an enzyme-linked immunosorbent assay with partial peptides of human serum albumin

“…In particular, measurements targeting toluene-2,4-diisocyanate (TDI) have been widely investigated as diagnostic markers, and enzymelinked immunosorbent assays (ELISAs) with TDI-HSA adducts have been used as a substrate challenge (Park et al, 2002). An anti-TDI haptenated protein monoclonal antibody was reported as a tool for biomonitoring of TDI exposure (Ruwona et al, 2011), and this antibody was also applied to sandwich ELISAs to detect aromatic diisocyanates adducts (Lemons et al, 2013).…”