The Impact of Baseline Serum Creatinine on Complete Remission Rate and Long-Term Outcome in Patients with Severe Lupus Nephritis

BACKGROUND/AIM: We assess the impact of serum creatinine at baseline on complete remission rate and long-term outcome in severe lupus nephritis (SLN). METHODS: A total of 86 adult patients with SLN [International Society of Nephrology/Renal Pathology Society (ISN/RPS) class IV lesions] were evaluated based on baseline serum creatinine levels (≤1.0, 1.01-1.5, 1.51-2.0, 2.01-3.0, and >3.0 mg/dl; n = 22, 23, 16, 12, and 13, respectively). The complete remission rates (serum creatinine level of ≤1.4 mg/dl and proteinuria of ≤0.33 g/day) and long-term outcomes (stable renal function, dialysis, and death) were compared. The patients were followed for 121 ± 64 months. RESULTS: The baseline clinical features were similar, but the chronicity index was significantly higher with increasing levels of serum creatinine. Complete remission rates were significantly higher in patients with lower levels of serum creatinine (86 vs. 52 vs. 19 vs. 25 vs. 0%, p < 0.0001). Patients with a baseline serum creatinine level of ≤1.0 mg/dl were >16 times as likely (OR 16.2; 95% CI: 4.2-61.5) to attain a complete remission and >6 times as likely (OR 6.1; 95% CI: 1.9-18.6) to have stable renal function at the last follow-up as compared to patients with a serum creatinine level of >1.0 mg/dl. The 15-year renal survival rate was greatest among those patients with a baseline serum creatinine level of ≤1.0 mg/dl (76 vs. 57 vs. 48 vs. 25 vs. 10%, p < 0.0001). CONCLUSION: The prognosis of SLN is significantly affected by the serum creatinine level at baseline. The complete remission rate is highest, and the long-term prognosis most favorable, in patients with a baseline serum creatinine level of ≤1.0 mg/dl. This emphasizes the importance of early diagnosis and treatment.