Abstract
Background. Literature data support the important role played by HLA molecules in predisposing to periodontitis. The present study evaluated possible associations between HLA class I and II phenotypes and stage III/IV grade C periodontitis in a Moroccan population.
Methods. The sample comprised 26 patients aged 15‒30 years, diagnosed with stage III/IV grade C periodontitis (case group) and 202 patients ethnically similar to the case group (control group). The patients underwent phenotyping for HLA class I molecules using the BIOTEST microlymphocytic plate technique and genotyping for HLA DR molecules. Bivariate analysis was performed using the chi-squared test at a significance level of P<0.05.
Results. The results showed a variable distribution of A alleles, without any specificity, predominantly in periodontitis cases compared with the controls. B21 allele was found with a lower phenotypic frequency (10.34%) in periodontitis cases compared with controls (31.18%) (χ2=5.40 and P=0.02). The phenotypic frequency of the DR6 allele was significantly lower in periodontitis cases (11.52%) compared with the controls (33.16%) (χ2=5.07 and P=0.024).
Conclusion. The present case‒control study reported a negative association between B21 and DR6 alleles and stage III/IV grade C Moroccan periodontitis cases compared with the controls with verified healthy periodontal status. This may help explain the particular profile of stage III/IV grade C periodontitis in Moroccan patients.