Efficacy and safety of hydroxychloroquine in IgA nephropathy with nasopharyngeal or intestinal mucosal and non-mucosal infections.

BACKGROUND

Hydroxychloroquine (HCQ) had shown efficacy in treating Immunoglobulin A nephropathy (IgAN). There are currently no clinical studies evaluating whether the efficacy and safety of HCQ differ in IgAN with concurrent nasopharyngeal or intestinal mucosal and non-mucosal infections at the time of diagnosis.

METHODS

This prospective multicenter cohort study enrolled patients aged > 18 years with biopsy-proven IgAN who had received optimized renin-angiotensin-aldosterone system inhibitor (RAASi) therapy for at least 1 month, 24-hour urinary protein creatinine ratio (UPCR) of 0.75–3.5 g/g and estimated glomerular filtration rate (eGFR) > 60 mL/min/1.73 m². At the time of IgAN diagnosis, patients were divided into the mucosal infection (MI) group and the non-mucosal infection (NMI) group based on whether they had mucosal infections, both groups of patients were treated with HCQ.

RESULTS

The study enrolled a total of 369 participants, consisting of 192 MI patients and 177 NMI patients. The mean age of the study participants was 37.58 years, with an average eGFR of 85.27 mL/min/1.73 m² and a baseline 24-hour UPCR of 1.92 g/g. After 12 months, the MI group showed a significant reduction in 24-hour UPCR, decreasing from 1.90 ± 0.76 g/g to 0.77 ± 0.31 g/g, with a mean reduction of 58.6%. In contrast, the NMI group had a more modest decline, from 1.94 ± 0.67 g/g to 1.08 ± 0.44 g/g, averaging a 43.8% reduction. Complete remission rate was achieved in 58.3% (n = 112) of the MI group and 47.5% (n = 84) of the NMI group (HR: 1.56, 95% CI: 1.15–2.13, P = 0.004). The overall remission rate was 66.1% (n = 127) in the MI group and 57.6% (n = 102) in the NMI group (HR: 1.65, 95% CI: 1.23–2.21, P < 0.001). Renal function remained stable, no severe adverse events were reported.

CONCLUSION

HCQ combined with optimized RAASi safely and effectively reduced proteinuria in IgAN, with particularly superior efficacy observed in patients with concurrent nasopharyngeal or intestinal MI. CLINICAL TRIAL NUMBER: Not applicable.