Dermatitis herpetiformis (DH) is a rare autoimmune bullous dermatosis. There are only few HLA studies among DH patients and data among the Bulgarian population are scarce. Research in the field has indicated DH association with HLA DQ2 (DQA1*05:01 & DQB1*02) and DQ8 (DQA1*03:01 & DQB1*03:02) in Caucasians. The aim of our study was to evaluate the HLA-DQB1 typing among Bulgarian DH patients. A total of 37 DH patients (24 men, 13 women) and 41 healthy controls (22 men, 19 women) were analyzed. DNA was extracted from blood samples using iPrep PureLink (Invitrogen). HLA-DQB1 typing was performed by PCR-SSP with Olerup SSP DQ low resolution kit. Arlequin software package was used for calculating HLA allele frequencies by expectation-maximization algorithm. Chi square and Fisher’s exact tests were applied for comparative analysis among groups. P values were adjusted via Bonferroni correction for multiple comparisons. The diagnostic value of the HLA typing was also assessed by calculating sensitivity, specificity, positive and negative predictive values (PPV and NPV), test accuracy (V), probability ratios (LR + and LR-) at 95% confidence interval (CI). Our results indicate that HLA DQ2/DQ8 sensitivities correlate with the published data on Caucasians, however only HLA DQ2 has a value of a statistically significant predisposing factor in the Bulgarian population from the studied serologic specificities. Due to its high NPV (100%), HLA DQ2/DQ8 genotyping is applicable in certain cases requiring the exclusion of the disease using DQB1 low resolution kit. HLA DQ7, which in the Bulgarian population in haplotype with DRB1*11 is protective for the development of different autoimmune diseases, has also a statistically significant protective effect for DH. In conclusion, our data confirm some of the previously described DQ associations in Caucasians, reveal additional protective associations and justify the implementation of HLA-DQ genotyping in diagnostic algorithms of DH.

ESDR184 - HLA-DQB1 associations among Bulgarian patients with dermatitis herpetiformis

50th Annual Meeting of the European Society for Dermatological Research. VIRTUAL MEETING