Digital gangrene in systemic sclerosis patients: not only due to the microvascular disease.

Objective: This study aims to investigate the characteristics, risk factors, and outcomes of digital gangrenes in SSc patients, and to identify whether vasculitis is one of the causes for digital gangrene.

Methods: A retrospective case-control study was performed from February 2003 to April 2021. Forty-three SSc patients with digital gangrene admitted to Peking Union Medical College Hospital were included. One-hundred forty-six age- and sex-matched SSc patients without gangrene were selected as controls during the same period. Univariate and multivariate logistic regression analysis was used to determine risk factors.

Results: Among 43 SSc patients with gangrene, 93.0% had Raynaud's phenomenon (RP) and 32.6% had current or previous digital ulcers (DU). SSc patients with digital gangrene had more ESR elevation (54.8% vs. 34.9%, p = 0.020) and higher level of high-sensitive C reactive protein (median 7.2 mg/L vs. 1.8 mg/L, p = 0.045) compared with controls. In the multivariable logistic regression analysis, smoking history (OR 4.119, p = 0.037), anti-centromere antibody positivity (OR 3.542, p = 0.016), anti-neutrophil cytoplasmic antibody positivity (OR 22.605, p = 0.037), and anti-phospholipid antibody positivity (OR 16.563, p = 0.001), as well as elevated ESR (OR 2.524, p = 0.038) were identified as independent risk factors for gangrenes. Most (79.1%) cases were treated with combination of immunosuppressive and vasodilating therapy, and four cases also got remised after treatment of only glucocorticoid and immunosuppressive agent.

Conclusion: Smoking history; positive-ACA, ANCA, and anti-phospholipid antibodies; and increased ESR were independent risk factors for digital gangrenes in SSc. Vasculitis and macrovascular disease may contribute to the progression of digital gangrenes. Key Points •18.6% of SSc patients with digital gangrene had macrovascular stenosis. •Smoking, positive-ACA, ANCA, aPL, and increased ESR were indicators for digital gangrenes in SSc. •Vasculitis and macrovascular disease may involve in the pathogenesis.