Shared epitope classification methods according to Gregersen and de Vries allow adequate characterization of patients with rheumatoid arthritis in a Colombian population

Abstract

IntroductionThe most important genetic association in rheumatoid arthritis (RA) is presented with some alleles from the HLA-DRB1 gene that encode the shared epitope (SE). ObjectivesTo apply the SE classification methods of Gregersen, de Vries, Raychaudhuri, Mattey, and Tezenas du Montcel in a group of Colombian patients with RA and determine the most common HLA-DRB1 alleles in the population. MethodsRA diagnosis, genetic study of the HLA-DRB1 region using Luminex technology in 50 RA and 50 healthy subjects. For the classification analysis, Fisher's exact test and chi-squared test were applied. Tables were created to count the RA-related alleles. We used odds ratio to determine the risk between the presence of the shared epitope (SE) and anti-cyclic citrullinated peptides (Anti-CCP). ResultsGregersen and de Vries methods were suitable for the characterization of RA in this population (p = .006). The most prevalent HLA-DRB1 alleles in the RA group were 14:02, 04:04, 08:02, 04:05, and 10:01. High frequencies of the 07:01, 03:01, 13:02, 01:02, and 12:01 HLA-DRB1 alleles were found in the healthy population. HLA-DRB1 alleles with similar distribution in both populations were 04:07, 15:01, 11:01, 16:02, and 01:01. A high frequency of SE + was observed in Anti-CCP + individuals (63.15%); however, this was not statistically significant [OR 2.4 (.63–9.01); p = .19]. ConclusionThe SE classification methods of Gregersen and de Vries were adequate in characterizing RA in a Colombian population group. An equivalence of 100% was verified between the susceptibility alleles defined by de Vries and the alleles assigned as SE according to Gregersen.