Gender differences in axial spondyloarthritis

Within the concept of axial spondyloarthritis(ax Sp A), relevant differences between men and women have been described for patients with the radiographic disease form [ankylosing spondylitis(AS)]. The subjective perception of disease activity(spinal and peripheral pain, fatigue, morning stiffness) has been shown to be higher in female than in male patients. Moreover, women experience more functional limitations and a lower quality of life, despite lower degrees of radiographic spinal damage. Peripheral clinical involvement(arthritis and enthesitis) is, additionally, more predominant in women. On the other hand, a higher level of objective signs of inflammation(C-reactive protein, erythrocyte sedimentation rate, magnetic resonance imaging of sacroiliac joints and spine) has been reported in men. Whether these differences might explain the better response to treatment with anti-tumor necrosis factor agents observed in male patients remains unclear. The underlying causes of the discrepancies are still unknown and genetic, environmental, cultural and/or societal factors may be involved. While AS is still more prevalent in men in a ratio of 2-3:1, the prevalence of males and females in patients with ax Sp A without radiographic sacroiliac damage is similar. Gender differences in this subgroup of patients have not been adequately addressed, and are particularly needed to further validate the Assessment of Spondylo Arthritis international Society classification criteria.