Objective: To investigate the association between genetic polymorphisms of human leukocyte antigen-DQ (HLA-DQ) and susceptibility to trichloroethylene (TCE)-induced severe generalized dermatitis.
Methods: A case-control study was conducted which included 112 patients with TCE-induced severe generalized dermatitis and 142 healthy controls exposed to TCE in the same workshop. The DNA sequences in exon2 of HLA-DQA1 and HLA-DQB1 were performed by direct sequencing of polymerase chain reaction (PCR) products. The frequencies distribution of allelic genotypes and codon polymorphisms were compared.
Results: The frequencies of DQA1*0201 and 060101/0602 in cases [7.6% (17/224) and 16.1% (36/224)] were significantly higher than those of the exposed controls [3.5% (10/284) and 7.0% (20/284)], while frequencies of DQA1*0103 and 050101/0503/0505 in cases [5.8% (13/224) and 8.9% (20/224)] were significantly lower than those of exposed controls [10.9% (31/284) and 17.3% (49/284)]. In terms of codon polymorphisms, there were 5 codons of DQA1 (25, 41, 52, 54 and 69) showing significant differences between cases and controls. There were no significant differences in the frequencies of allelic genotypes of HLA-DQB1 between cases and exposed controls.
Conclusion: The genetic polymorphisms of HLA-DQA1 might be one of the factors influencing the individual susceptibility to TCE-induced severe generalized dermatitis.