Different ethnic background is associated with distinct clinical profiles in the spondyloarthritides in the North and South of Brazil

The objective of this study was to analyze the clinical profile of the spondyloarthritides (SpA) in distinct Brazilian regions. A common protocol of investigation was prospectively applied to 202 SpA patients, including 138 patients from the South and 64 patients from the North. All the patients were classified as axial or peripheral SpA. Clinical and demographic variables and disease indexes were analyzed. Bonferroni correction was used to adjust the level of significance of each test; results with p value < 0.003 were considered statistically relevant. White ethnicity was associated with positive HLA-B27, while non-Whites presented higher frequency of peripheral arthritis, although not statistically significant. When comparing non-White patients from the North with those from the South, the Southerners presented significantly higher scores of Ankylosing Spondylitis Disease Activity Score using C-reactive protein (p = 0.001) and Health Assessment Questionnaire (p = 0.001). Although not statistically significant, Northern non-White patients were more frequently males, while Southerners had higher frequency of anterior uveitis and higher Bath Ankylosing Spondylitis Disease Activity Index and Ankylosing Spondylitis Quality of Life. Brazilian SpA patients present distinct patterns of disease according to the geographic region, especially regarding the non-White populations.