Chest pain without radiographic sacroiliitis in relatives of patients with ankylosing spondylitis.

The prevalence of complaints of thoracic pain or stiffness in the past 6 months was assessed by examination, HLA typing and sacroiliac radiographs in 420 relatives of 275 B27+ probands with ankylosing spondylitis (AS). AS or sacroiliitis was found in 15 of 420 relatives (3.6%). The gender of the proband did not influence the probability of AS or sacroiliitis among the relatives. In the absence of sacroiliitis, B27+ relatives had chest pain more often (31 of 208, or 14.9%) than B27- relatives (13 of 197, or 6.6%) (p less than 0.01). Chest pain assessed by questionnaire was associated with pain on pressure at the costosternal junctions. The concept of AS as a combination of radiographic sacroiliitis plus clinical signs or symptoms may be too narrow.