The Clinical Significance of Serum Biomarkers of the Intestinal Barrier in Systemic Sclerosis: A Cross-Sectional Study

Systemic sclerosis (SSc) is an immune-mediated connective tissue disease. Recent studies reported differences in the composition of intestinal microbiota (dysbiosis) in patients with SSc compared to nonsclerodermic subjects. Dysbiosis may disrupt the intestinal barrier, which leads to immunological activation via microbial antigen and metabolite translocation. The study aimed to assess the differences in intestinal permeability between SSc patients and controls and to examine the correlation between intestinal permeability and complications of SSc. The study comprised 50 patients with SSc and 30 matched subjects. Serum intestinal permeability markers: intestinal fatty acid binding protein, claudin-3, and lipopolysaccharides (LPS) were determined using an enzyme-linked immunosorbent assay. SSc patients had a significantly increased concentration of LPS compared to control subjects (232.30 [149.00-347.70] versus 161.00 [83.92-252.20] pg/mL, p < 0.05). The patients with shorter SSc duration (<= 6 years) had an increased concentration of LPS and claudin-3 compared to the subgroup with longer disease length: LPS (280.75 [167.30-403.40] versus 186.00 [98.12-275.90] pg/mL, p < 0.05), and claudin-3 (16.99 [12.41-39.59] versus 13.54 [10.29-15.47] ng/mL, p < 0.05). The patients with esophageal dysmotility had a decreased LPS level compared to those without this complication (188.05 [102.31-264.40] versus 283.95 [203.20-356.30] pg/mL, p < 0.05). Increased intestinal permeability in SSc may exacerbate the course of the disease and increase the risk of developing complications. Lower LPS levels in SSc might be a hallmark of esophageal dysmotility.