Overall improvement in early diffuse cutaneous systemic sclerosis (dcSSc) severity is associated with improvements in skin at both 1 year and 2 years, suggesting skin improvement may be a helpful indicator for improvement of global disease severity in clinical trials, a study in Rheumatology (Oxford) reports.
Patients in the Canadian Scleroderma Research Group database who had a diagnosis of dcSSc and a modified Rodnan skin score (mRSS) of ≥7 and a follow-up of 1 year (n=154) and 2 years (n=128) were included in the analysis. All patients had a disease duration of ≤5 years and had no evidence of end-stage organ damage and/or significant comorbidity at their initial visit.
In both follow-up cohorts, researchers assessed skin using the mRSS, and disease severity was evaluated using the summed Medsger disease severity score (DSS; without skin domain). Physician and patient global assessments, function (Health Assessment Questionnaire Disability Index), and quality of life (36-item Short Form Health Survey physical component summary) were also assessed.
Approximately 50% of patients at 2 years had improved skin (mRSS decrease of ≥5 points and/or ≥25%). At 2 years, participants whose skin had improved had significantly better outcomes than those with stable skin, particularly in the summed DSS (P =.038), physician global assessments of disease damage (P =.001), Health Assessment Questionnaire Disability Index (P =.003), and 36-item Short Form Health Survey physical component summary (P =.034).
There were positive and significant correlations between changes in the mRSS and changes in summed DSS (P =.006). In 20.3% (n=26) of patients with worsened skin at 2 years (mRSS increase of ≥5 points and/or ≥25%), there were worse summed DSS (P =.01) and physician global assessment (P ≤.009) results.
The study authors acknowledged that an important limitation was that some measures likely included an intrinsic assessment of the severity of skin involvement that may contribute to the correlations found. For this reason, the primary outcome measure was summed DSS scores without the skin component. Other limitations of the analysis include the reduced sample size, as well as missing data for the summed DSS scores.
The researchers wrote that their findings “suggest the possibility that an improvement in the skin score in therapeutic trials may also correlate with an overall improvement in disease.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Zheng B, Nevskaya T, Baxter CA, et al; for the Canadian Scleroderma Research Group. Changes in skin score in early diffuse cutaneous systemic sclerosis are associated with changes in global disease severity [published online July 29, 2019]. Rheumatology (Oxford). doi:10.1093/rheumatology/kez299.