HLA-DR, -DQ and -DP alleles in nickel, chromium, and/or cobalt-sensitive individuals: genomic analysis based on restriction fragment length polymorphisms.

The increased concordance rate of nickel sensitivity in monozygotic compared to dizygotic twins indicates a genetic causal component. We have previously described an association in nickel-sensitive subjects with an HLA-DQA restriction fragment length polymorphism (RFLP) (4.5-kb TaqI band, DQA1*0501). The purpose of the present study was to investigate if our previous finding could be confirmed in an independent study, and also to investigate the distribution of HLA class II alleles in chromium- and cobalt-sensitive individuals. Using TaqI- or MspI-digested DNA and DQA, DQB, DRB, DPA and DPB cDNA probes alleles were defined by RFLP analysis. The association with the DQA1*0501 allele was not confirmed in the new group of 37 nickel-sensitive subjects (compared to 150 new controls), nor when the two groups of patients were combined. The distribution of HLA class II alleles and DR-DQ haplotypes were similar in the pooled group of 70 nickel-sensitive subjects and the combined control groups (n = 250). No significant changes in the distribution of HLA class II allele among the chromium- (n = 26) and/or cobalt- (n = 38) sensitive individuals were found. Our results indicate that it is unlikely that the tendency to develop metal sensitivity is associated with alleles of the HLA class II region.