Scleroderma renal crisis, an increasingly rare but persistently challenging condition: a retrospective cohort study.

Objective: Scleroderma renal crisis (SRC) is associated with high morbidity and mortality and there remain unmet needs regarding early identification and treatment. We aimed to assess risk factors for and the outcomes of SRC at a large Australian tertiary hospital.

Methods: Seventeen incident SRC cases were diagnosed between 2012 and 2022. Demographic, SSc manifestations and treatment data were extracted. Using data from the Australian Scleroderma Cohort Study (n = 483), logistic regression analysis was performed to identify risk factors for SRC.

Results: The prevalence of SRC was 3.52%. The median SSc disease duration at SRC onset was 2 years [interquartile range (IQR) 1-4]. Peak creatinine occurred at a median of 11 days (IQR 5-14) post-SRC diagnosis, with a median peak creatinine of 144 µmol/l (IQR 86-306). Nine (52.94%) SRC patients had evidence of acute neurologic and/or cardiac complications. Acute haemofiltration was required in 3 (17.65%) patients. Over the follow-up period, 7 (41.18%) SRC patients died 2.75 years (IQR 0.74-7.25) after SRC onset. Patients with SRC were more likely to be male [odds ratio (OR) 9.73 (95% CI 3.57, 26.56)], have diffuse disease [OR 23.16 (95% CI 5.22, 102.80)] and have antibodies to Scl70 [OR 3.34 (95% CI 1.24, 9.04)] or RNA polymerase III (RNAPIII) [OR 5.15 (95% CI 1.91, 13.89)].

Conclusion: SRC is an uncommon manifestation, but outcomes remain poor. A significant proportion of patients presenting with SRC in Australia are positive for Scl70 or RNAPIII antibody. Despite relatively low peak serum creatinine and rates of renal replacement therapy, SRC was still associated with significant mortality.