PO:31:169 | From Crisis to Chronicity: A Real-World Study of Renal Dysfunction in Systemic Sclerosis

Stefano Stano¹, Fabio Cacciapaglia^1|2, Giorgia Campanale¹, Simone Perniola¹, Maria Morrone¹, Andrea Cito¹, Vincenzo Venerito¹, Maria Grazia Anelli¹, Giuseppe Lopalco¹, Florenzo Iannone¹ | ¹Rheumatology Unit - Department of Precision and Regenerative Medicine, Jonian Area DiPReMeJ, University of Bari Bari, Italy; ²Rheumatology Service, Internal Medicine Unit F. Miulli General Hospital, Department of Medicine and Surgery, LUM Casamassima, Italy

Introduction. Renal involvement in systemic sclerosis (SSc) results from a multifactorial pathogenesis, including renal vasculopathy, complement activation, and dysregulation of vasoactive mediators, all of which may be influenced by therapeutic interventions. Although the management of scleroderma renal crisis (SRC) has improved, renal complications are prevalent and associated with adverse outcomes[1]. Chronic kidney impairment unrelated to SRC, however, is underreported in the SSc population[2].

Objectives. This study aimed to explore clinical features of SSc patients with and without impaired renal function.

Methods. Patients fulfilling the 2013 ACR/EULAR classification criteria for SSc[3] and with at least two documented assessments of renal function were included. Estimated glomerular filtration rate (eGFR) was calculated using the Cockcroft-Gault equation, incorporating age, weight, and serum creatinine. Patients with eGFR <70 ml/min/1.73m² at the last follow-up were defined as having ‘impaired’ renal function, while those with higher values were classified as having ‘preserved’ function. Clinical data were retrospectively extracted from medical records and analyzed using appropriate statistical tests (GraphPad Prism v9).

Results. A total of 395 patients were included (89.6% female; median age 65 years, IQR 54-74), and 188 (47.6%) had ‘impaired’ eGFR (Table). Three patients (0.8%) had a history of SRC. Those with ‘impaired’ renal function were significantly older, had longer disease duration, and were more frequently anti-centromere antibody (anti-CENP) positive (p<0.05), and surprisingly less often anti-TopoI positive (p<0.01). Nor were there any differences in other autoantibodies, hypocomplementemia, or proteinuria rates across groups, as well as modified Rodnan skin scores, telangiectasias, digital ulcers, calcinosis, and interstitial lung disease. Pulmonary hypertension (p<0.001) and pericardial effusion (p<0.01) were significantly more prevalent among patients with ‘impaired’ eGFR, suggesting possible cardiocirculatory hemodynamic or diuretic overload. Conversely, pitting scars were less frequent in this group (p=0.01). Systemic hypertension (p<0.001) and osteoporosis (p<0.0001) were also more commonly observed in patients with reduced eGFR. Therapeutic patterns differed between groups: calcium channel blockers, conventional synthetic and biologic immunosuppressive agents were more frequently used in patients with ‘preserved’ renal function (all p<0.001), whereas corticosteroid use was significantly higher in those with ‘impaired’ function (p<0.001). The prevalence of neoplasms and other autoimmune diseases, as thyroiditis and primary biliary cholangitis, did not differ significantly.

Conclusions. SSc patients with eGFR <70 ml/min/1.73m² more frequently exhibit systemic hypertension, pulmonary hypertension, and pericardial effusion, potentially reflecting underlying cardiocirculatory stress. Use of calcium channel blockers and immunosuppressive drugs appears associated with preserved renal function. These findings highlight the importance of regular renal monitoring and early intervention in SSc to mitigate renal and systemic complications.