RESUMEN
OBJECTIVES: Patients with systemic sclerosis present with severe gastroesophageal reflux disease, often refractory to proton-pump inhibitors (PPI) treatment. The aim of the present study was to identify factors associated with PPI-refractory esophagitis. METHODS: We performed a cross-sectional study in a single-center cohort of patients diagnosed with systemic sclerosis. We included patients who underwent an esophagogastroduodenoscopy while on PPI treatment. Patients with PPI-refractory erosive esophagitis were compared with those with endoscopically normal esophageal mucosa. RESULTS: A total of 69 patients were included, from these, 23 patients (33%) had PPI-refractory esophagitis (Grade A, n = 11; Grade B, n = 7; Grade C, n = 2; Grade D, n = 3) and 46 (67%) had an endoscopically normal esophageal mucosa. On univariate analysis, patients with PPI-refractory esophagitis were more frequently diffuse SSc subset (43% vs 17%; p= 0.041). Evaluating gastrointestinal motility tests, neither absent esophageal contractility (39% vs 25%, p= 0.292) nor hypotensive lower esophageal sphincter (47% vs 44%, p= 0.980) were significantly associated with PPI-refractory esophagitis. Gastrointestinal dysmotility, defined as abnormal gastric emptying and/or small bowel dilated loops, was significantly associated with PPI-refractory esophagitis (66 vs 8%, p = <0.001). On a multivariate regression model to evaluate the association between motility test results adjusted for the diffuse subset, gastrointestinal dysmotility (ß = 0.751, p= 0.010) was independently associated with PPI-refractory esophagitis, while absent esophageal contractility (ß = 0.044, p= 0.886) or a hypotensive LES were not (ß=-0.131, p= 0.663). CONCLUSIONS: Our findings suggest that gastric and small intestinal motor dysfunction may be an important contributor to the development of PPI-refractory esophagitis in patients with systemic sclerosis.
RESUMEN
OBJECTIVES: Systemic sclerosis (SSc)-specific autoantibodies allow the diagnosis and predict the prognosis of SSc patients with different clinical characteristics. The aim of this study was to describe new SSc-related autoantibodies by a novel protein immunoprecipitation (IP) assay. METHODS: Serum samples and clinical data were collected from 307 SSc patients. Antinuclear autoantibodies were tested in all patients by indirect immunofluorescence (IIF) on HEp-2 cells. SSc-specific autoantibodies were evaluated with a commercial immunoblot and chemiluminescence immunoassay, and traditional RNA-IP. Patients negative for all these autoantibodies (n = 51) were further tested with a non-radioactive protein IP assay. Protein bands detected on SDS-PAGE were then analysed by mass spectrometry (MS) and confirmed by western blot (WB). Additional 56 patients with nucleolar pattern by IIF were tested by protein IP-WB. RESULTS: Five patients who underwent protein IP testing showed a 110-115kDa molecular weight band on SDS-PAGE and a homogeneous nucleolar pattern by IIF. MS identified the bands as nuclear valosin-containing protein-like (NVL). An additional positive patient was detected by IP-WB. As compared with the remaining 101 negative patients, anti-NVL positive patients showed a greater prevalence of calcinosis (100% vs 18.9%, p< 0.001), and cancer (66.7% vs 8.9%, p= 0.002), with a particular association with synchronous cancer (OR = 16.3; p= 0.024). CONCLUSION: We identified NVL as a new autoantibody target by a novel protein IP assay in SSc patients with a homogeneous nucleolar IIF pattern, testing negative for all known SSc-specific autoantibodies by commercial assays and RNA IP. Anti-NVL identifies a new clinical phenotype, characterized by calcinosis and cancer.