Background/Purpose: Interstitial lung disease (ILD) is a common but fatal complication of systemic sclerosis (SSc). Gastroesophageal reflux disease (GERD) may be related to pathogenesis of ILD, but some study failed to show relationship between acidic GER and ILD. Our aims are to find relevant reflux parameters related to ILD in patients with SSc using high-resolution esophageal manometry (HRM) and multichannel intraluminal impedance and pH monitoring (MII-pH).

Methods: Of the consecutive 16 female patients with SSc, 9 patients showed ILD (SSc-ILD, median age 45 years, range 25-55) by HRCT and 7 patients didn’t (SSc-N, age 49.5 y, 31-62). They all received esophageal HRM (Given Imaging, Los Angeles, CA, USA) and MII-pH (Sandhill Scientific, Inc.; Highland Ranch, CO, USA). We compared HRM parameters (Chicago ver 3.0) and MII-pH parameters including baseline impedance (BI) and post-reflux swallow-induced peristaltic wave (PSPW) index between two groups.

Results: SSc-ILD showed significantly low FVC%pred and DLCO% compared with SSc-N (mean± SD, 72.2±17.1% vs. 101.3±14.2; 56.1±12 vs. 71.9±13.2, respectively, P<0.05) In HRM, absent contractility, ineffective esophageal motility and normal peristalsis were 6, 2, 1 in SSc-ILD and 1, 4, 2 in SSc-N. LES pressure was significantly low in SSc-ILD compared with SSc-N (13.7±6.4 vs. 24.0±11.3 mmHg, p<0.05). IRP, DCI, and UES pressure were not different between two groups. In MII-pH, all reflux % time using pH and impedance according to acidity or position, number of reflux events, and proximal extent were not different between two groups. However, mean bolus clearance time was longer in SSc-ILD than SSc-N [median 14 sec (IQR 13-28) vs. 11 sec (8.5-12.8), p<0.05]. BI except the most distal esophagus were significantly low in SSc-ILD than SSc-N (1099.2±327W vs. 2066.1±754.6W, 1032.9±483.2W vs. 2118.4±724.2W, 1190.7±745.3W vs. 2498.3±528.2W, p<0.005; 1257.8±959.7W vs. 2695.7±841.2W, P<0.01; 1239.9±907.4W vs. 2327.9±542.3W, P<0.05 at 17, 15, 9, 7, and 5 cm above the LES). PSPW index was significantly low in SSc-ILD than SSc-N [median 0 (IQR 0-0.03) vs. 0.16 (0.07-0.45), p<0.05].

Conclusion: Pathogenic mechanisms of ILD in SSc may relate to proximal esophageal reflux (low proximal esophageal BI) and decreased clearance mechanisms due to esophageal involvement of SSc.

« Back to 2017 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/low-baseline-impedance-in-proximal-esophagus-and-decreased-pspw-index-may-related-with-pathogenesis-of-interstitial-lung-disease-in-systemic-sclerosis/