Creatinine clearance rate predicts prognosis of patients with systemic lupus erythematosus: a large retrospective cohort study.

OBJECTIVE: To explore the association between the creatinine clearance rate (Ccr) and the prognosis of patients, and compared with estimated glomerular filtration rate (eGFR). METHODS: We retrospectively collected information of patients with SLE who were first hospitalized between 1999 and 2009 in Jiangsu Province, China, and followed up in 2010 and 2015. Ccr was calculated and dichotomized into normal group (Ccr ≥ 70) and decreasing group (Ccr < 70). The clinical characteristics of the two groups were compared and Cox proportional-hazards regression models were used to calculate hazard ratio (HR) and 95% confidence interval (CI). RESULTS: Among 1990 SLE patients, we observed 437 (22.0%) with decreased Ccr, including 237 cases (11.9%) with mild renal dysfunction, 136 cases (6.8%) with moderate renal dysfunction, and 64 cases (3.2%) with severe renal dysfunction. Compared to normal Ccr, decreasing Ccr had a higher risk for mortality with adjusted HR (95% CI) of 2.21 (1.59-3.06). Dose-response relationships were significantly found between increased mortality of SLE and decreased Ccr (p for trend < 0. 001), as well as eGFR. Positive associations were consistently observed in subgroups, such as systemic lupus disease activity index (SLEDAI) ≥ 15, without comorbidities and abnormal laboratory indexes. Decreasing Ccr was positively associated with mortality from infection and renal failure with HR (95% CI) of 1.80 (1.02-3.19) and 6.84 (3.05-15.36). CONCLUSIONS: A significant association has been observed between decreased Ccr and increased risk for mortality of SLE patients. Early clinical interventions to modulate the Ccr of SLE patients may be beneficial to their survival. Key points • Decreasing creatinine clearance rate (Ccr) was positively associated with an overall mortality of SLE patients, with a dose-response relationship. • Moreover, decreasing Ccr was associated with elevated mortality primarily due to infection and renal failure.