The Importance of HLA-B27 in the Evolution of Reactive Arthritis.

Reactive arthritis is an inflammatory joint disease which develops after 1-4 weeks following an enteral, genital or ORL infection, with a higher frequency in HLA-B27 positive patients. AIMS: The objective of this paper is to study the importance of HLA-B27 antigen in the development of reactive arthritis. PATIENTS AND METHODS: The transversal, observational study was conducted in the Rheumatology Clinic of the University of Medicine and Pharmacy of Craiova during the period 2012-2015 and included 112 patients. They were divided into three groups, as follows: group I (52 reactive arthritis cases), group II (30 other spondyloarthritis cases), group III (40 osteoarthritis cases). ELISA and PCR techniques were used to determine the antigen. RESULTS: Those whom had this genetic marker present, the number of enthesitis almost doubled highlighting a possible correlation between the antigen and these imaging changes. We can confirm the same thing for the erosions as well. Unlike enthesitis, erosions occurred also in group III (37.5%), but if we refer to the first two groups, we will observe a significant relationship regarding HLA-B27. More specifically, in HLA-B27 positive patients (68.97%), erosions were found to be twice as numerous than in HLA-B27 negative patients (31.03%). In group I we identified stage 2 sacroiliitis in 68% of HLA-B27 positive patients and 32% in HLA-B27 negative, which shows another link to this antigen with both joint destruction and a possible unfavorable evolution of reactive arthritis. CONCLUSIONS: This antigen specific to the seronegative group of spondyloarthritis determines the acceleration of articular destruction, translated by erosion, and the evolution of sacroiliitis to a more advanced stage.