A Comparison of Gastrointestinal Disease Severity in African American and Caucasian Scleroderma Patients

Background/Purpose: Systemic sclerosis (SSc) is a multisystem autoimmune disease. After skin involvement and RaynaudÕs, the gastrointestinal tract is the most commonly affected organ system with up to 90% of SSc patients affected. A limited number of studies suggest that African American (AA) SSc patients, particularly those with a nucleolar pattern anti-nuclear antibody, may be more likely to develop severe SSc-GI disease than Caucasian (C) SSc patients. The aims of this study are to determine if a patientÕs race or SSc-specific autoantibody profile is associated with the severity of SSc-GI disease.

Methods: A retrospective analysis of patient responses to the University of California Los Angeles Scleroderma Clinical Trials Consortium Gastrointestinal Tract questionnaire (GIT 2.0), demographic information (age, sex, disease duration, disease subtype), scleroderma-specific autoantibody profile (Nucleolar pattern ANA (NUC), anti-centromere (ACA), SCL-70, RNA Polymerase III (POL 3), and U1-RNP and Medsgar Gastrointestinal Disease Severity Score (Medsger GI Score) were extracted from the medical records of  70 AA SSc patients and 84 C SSc patients seen in the department between 2014 and 2016. SSc patients complete the GIT 2.0 at each clinic visit but only the first response was included for data analysis. Statistical analyses were carried out using Shapiro-Wilk, Kruskal-Wallis and Chi-Square tests.

Results: AA pts were younger, more likely to have diffuse cutaneous disease and had shorter disease duration (Table 1). More AA had NUC and U1 RNP antibodies whereas C were more likely to have ACA and Pol 3.  The Medsger GI score was slightly higher in AA compared to C (1.29 vs 1.0, p=0.06).   AA pts   scored significantly higher on the GIT 2.0 in the reflux, diarrhea, and social function sections, as well as the total score (p=0.02).  There were no significant associations of the GIT 2.0 with the NUC, although patients with U1-RNP had the highest GIT 2.0 total score and pts with POL 3 had the lowest total score. The GIT 2.0 correlated with the Medsger GI Score (r= 0.431 p<0.001) even though the Medsger GI Score does not include some of the features in the GIT 2.0.

Conclusion: This study suggests that AA may have more severe SSc GI disease as demonstrated by the Medsger GI severity score and the GIT 2.0.  Using the GIT 2.0 in clinical practice can easily identify pts with significant GI symptoms, which should be treated. By identifying SSc patients at risk of developing significant GI system involvement, practitioners can perform targeted organ surveillance based on subset risk stratification levels and provide patients with earlier interventions when treatment is most effective. Table 1