Current studies of HLA-associations in juvenile idiopathic arthritis (JIA) are directed at detection of the hallmarks of the disease, which may significantly improve the diagnostics for JIA.
The purpose of this study was to determine the incidence of HLA B27 in children with JIA in Ukraine and to evaluate the natural history of the disease in HLA B27-positive patients.
In this study, seventy-two children with JIA were tested for HLA B27. The diagnosis of JIA was established according to the ILAR criteria, 1997-2001. HLA B27 was detected by a flow cytometry method on FACSkan using monoclonal anti-HLA B27 antibodies. The control group comprised 40 children with reactive arthritis and 17 healthy children. For the analysis of clinical data, children with JIA were divided into 2 groups. The first group consisted of 31 HLA B27-positive patients, the second of 41 children with negative HLA B27. HLA B27 was found in 43% of the children with JIA. It was observed that HLA B27-positive male patients had a significantly higher incidence of the development of JIA (p = 0.0005). In the presence of HLA B27 a significant association between the onset of JIA and the age of children was postulated (p = 0.0003). It was established that HLA B27 is a diagnostic criterion of enthesitis-related JIA (p = 0.0000). The patients with enthesitis-related HLA B27-positive JIA had joint damage in the form of asymmetric arthritis of the large joints (p = 0.0006) and enthesitis in different localizations (p = 0.0121). Dactilitis is a hallmark of enthesitis-related JIA with positive HLA B27 (p = 0.0002) and reactive HLA B27 arthritis (p = 0.0167).