Increasing of SIgA serum levels may reflect subclinical intestinal involvement in non-radiographic axial and peripheral spondyloarthritis




Objective The evidence shows that previous infection with enteric pathogens is a requirement to develop pSpA. Based on our previous results, variances on regulation of SIgA might influence SpA activity; thus, the aim of this study was to correlate the levels of SIgA, IgA against some enteric bacteria, and IL-17, IL-21, and IL-6 with clinical features in a group of SpA patients. Methods Twenty-six pSpA, 20 nr-axSpA, 60 healthy volunteers (HV), and 34 patients with inflammatory bowel diseases (IBD) were included. All subjects were assessed to measure SIgA, total and specific IgA for enteric bacteria, and IL-17, IL-21, and IL-6 levels and clinical variables. For SpA patients, the diagnosis was verified 5 years after first evaluation to assess the risk of developing r-axSpA. Results SIgA levels were significantly higher in SpA patients than in HV and IBD (p < 0.0001 and p = 0.047, respectively). However, no differences for SIgA neither total IgA were found among the SpA subtypes (p = 0.624). Only IL-6 was higher in SpA than HV (p = 0.013). An inverse correlation was demonstrated for SIgA and BASFI (r: − 0.45; p = 0.003), BASDAI (r: − 0.39; p = 0.0123), ASDAS-CRP (r: − 0.37; p = 0.014), and ASDAS-ESR (r: − 0.45; p = 0.0021). There was no evidence of risk of developing r-axSpA in patients who previously showed high levels of serum antibodies. Conclusion The results show that pSpA as well as nr-axSpA share a similar SIgA-intestinal involvement independently of a previous infection. This suggests that serum SIgA increases are evidence of subclinical intestinal compromise which could have influence on disease activity but not in this progression.

Palabras clave


ASDAS, BASDAI, Intestinal disease, Secretory immunoglobulin A (SIgA), Spondyloarthritis