Is HLA-B27 a useful test in the diagnosis of juvenile spondyloarthropathies?

Seronegative spondyloarthritis (SSA) is a type of arthritis that involves joints in the spine, as well as the hips, shoulders, knees and ankles. The diagnosis of juvenile spondyloarthritis is rarely entertained in young children who present with back and leg pain. The aim of the present study was to assess the role of HLA-B27 as a diagnostic marker in children with spondyloarthropathy, and correlation of HLA-B27 with radiological features and tuberculosis. Routine haematological and immunological tests were done by standard method and HLA-B27 typing was done by the lymphocytotoxicity method. A total of 70 cases of juvenile spondyloarthropathy were studied from May 2006 to September 2007. It included both males and females. Positivity of HLA-B27 in childhood SSA was only 71.4 percent (50/70). Gender-wise analysis showed that 76.7 percent (46/60) males and 20.0 percent (2/10) of the female patients were HLA-B27 positive. In HLA-B27-positive cases, the sacroiliac, hip, ankle, lower spine and knee joints were more involved. Urinary tract infection, diarrhoea and constipation were more common in HLA-B27-positive cases. None of the HLA-B27 cases were positive for rheumatoid factor; however, C-reactive protein was raised in 60.5 percent. In bilateral/unilateral sacroiliitis diagnosed by radiographs, only 81.5 percent patients were HLA-B27 positive. Tuberculosis was diagnosed in 14.3 percent (10/70) of total cases in which HLA-B27 positivity was seen in 60 percent of cases (6/10). Our study concludes that both HLA-B27 and radiological tests should be done in male children suspected to have SSA, because it can indicate early cases of juvenile spondyloarthropathy when radiological changes are not present, and it produces a more severe disease. HLA-B27 positivity probably also predisposes to tuberculosis.