Induction Therapy for Class I/II Lupus Nephritis with Glucocorticoid Monotherapy associates with Higher Relapse and Poorer Kidney Outcomes

The efficacy of glucocorticoid (GC) in combination with other immunosuppressive therapy for class I/II lupus nephritis (LN) remains controversial. We retrospectively analysed 107 biopsy-proven class I/II LN patients who had survival follow-up data from January 1996 to March 2023 and further assessed 96 patients with available treatment response data. These patients received GC alone (GC monotherapy) or GC in combination with another immunosuppressant (combination therapy) as induction therapy. The primary outcome was renal relapse and the secondary outcome was end-stage renal disease (ESRD) or all-cause mortality. Kaplan-Meier analysis was used to compare the cumulative renal relapse rate and long-term renal outcomes between the two treatment groups. Cox regression analysis was performed to identify the risk factors for renal relapse. During a median follow-up of 112 months [interquartile range (IQR) 35.5-189.0], 96 patients had available treatment response data. All patients had complete or partial remission, with 78 (81.3%) achieving complete remission (CR). No significant difference in CR rate was observed between the GC monotherapy and combination therapy groups (82.1% versus 80.7%, P = .868). However, the cumulative renal relapse rate was significantly higher in the GC monotherapy group (logrank P = .004). GC monotherapy {hazard ratio [HR] 2.71 [95% confidence interval (CI) 1.28-5.75], P = .009} and partial remission after induction therapy [HR 4.17 (95% CI 1.78-9.80), P = .001] were independent risk factors for renal relapse. After a median follow-up time of 156 months (IQR 76.0-199.0), four patients (3.7%) developed ESRD, all in the GC monotherapy group. Long-term renal outcome in the GC monotherapy group was significantly poorer, with 5-, 10-, 15- and 20-year renal survival rates of 100.0%, 93.9%, 90.4% and 90.4%, respectively (P = .025). Class I/II LN patients treated with GC monotherapy have higher renal relapse rates and poorer long-term renal outcomes compared with those receiving GC in combination with other immunosuppressants as induction therapy.