OBJECTIVE: to evaluate first-degree relatives of ankylosing spondylitis (AS) patients regarding to clinical, immunogenetic and radiological aspects. METHODS: fourteen patients with AS followed at the University Hospital of the Ribeirão Preto Medical School, University of São Paulo, Brazil (FMRP-USP) and thirty first-degree relatives were evaluated by clinical history, physical examination, HLA-B27 typing (by lymphocytotoxicity and flow cytometry), plain radiography and magnetic resonance imaging (MRI) of sacroiliacal joints. RESULTS: we found that 47% (14/30) of the relatives presented low back pain with inflammatory characteristics, 20% (6/30) fulfilled displayed radiological features of bilateral sacroiliitis, and 10% (3/30) fulfilled the criteria for ankylosing spondylitis. Sixty percent of the relatives were HLA-B27 positive, verified either by lymphocytotoxicity or flow cytometry. MRI was not more sensitive than conventional radiography in the detection of early changes of sacroiliitis. CONCLUSIONS: the evaluation of first-degree relatives of patients with ankylosing spondylitis may reveal oligosymptomatic and subclinical forms of the disease in a significant proportion of subjects.
ankylosing spondylitis; sacroiliitis; HLA-B27; flow cytometry; magnetic resonance imaging; familial investigation
