Antivinculin Antibodies in Systemic Sclerosis: Associations With Slow Gastric Transit and Extraintestinal Clinical Phenotype

Objective: The gastrointestinal (GI) tract is commonly affected in systemic sclerosis (SSc). A positive association between antivinculin antibody levels and GI symptom severity is reported in SSc. We sought to examine whether antivinculin antibodies associate with measures of GI dysmotility and extraintestinal clinical phenotype in SSc. Methods: A total of 88 well-characterized patients with SSc and GI disease were assayed for antivinculin antibodies by enzyme-linked immunosorbent assay. Whole-gut scintigraphy, GI symptom scores, and clinical features of SSc were compared between patients with and without antibodies. Results: Twenty of 88 (23%) patients had antivinculin antibodies, which were more prevalent in patients with slow gastric transit (35% versus 22%). In the univariate analyses, patients who were positive for antivinculin antibodies were more likely to have limited cutaneous disease (odds ratio [OR] 9.60 [95% confidence interval (95% CI) 1.19, 77.23]) and thyroid disease (OR 4.09 [95% CI 1.27, 13.21]). Such patients were also less likely to have lung involvement based on a Medsger Severity Score of ≥2 (OR 0.25 [95% CI 0.07, 0.92]). Higher levels of antivinculin autoantibodies were associated with less gastric emptying (β coefficient –3.41 [95% CI –6.72, –0.09]). The association between antivinculin antibodies and each of these clinical features remained significant in the multivariable model. In particular, the presence of antivinculin antibodies (β coefficient –6.20 [95% CI –12.33, –0.063]) and higher levels of antivinculin antibodies (β coefficient –3.64 [95% CI –7.05, –0.23]) were each significantly associated with slower gastric transit. Conclusion: Antivinculin antibodies associate with slower gastric transit in SSc and may provide insight into GI complications of SSc. (Figure presented.).