Long-term safety and efficacy of hydroxychloroquine in patients with IgA nephropathy: a single-center experience

Hydroxychloroquine (HCQ) has been used as a supportive therapy for IgA nephropathy (IgAN). We aimed to determine the long-term efficacy and safety of HCQ therapy in patients with IgAN. A total of 180 patients with IgAN who had received HCQ therapy for at least 1 year were enrolled in this study. The changes in proteinuria and the estimated glomerular filtration rate (eGFR) were analyzed during the follow-up period. The level of proteinuria decreased from 1.69 [1.24, 2.30] to 1.01 [0.59, 1.74] g/day (− 37.58 [− 57.52, 8.24] %, P < 0.001) at 12 months and to 1.00 [0.59, 1.60] g/day (− 55.30 [− 71.09, − 3.44] %, P < 0.001) at 24 months. There was no significant change in the eGFR of these patients at 12 months (65.82 ± 25.22 vs. 63.93 ± 25.96 ml/min/1.73 m2, P = 0.411); however, the eGFR decreased from 65.82 ± 25.22 to 62.15 ± 25.81 ml/min/1.73 m2 at 24 months (P = 0.003). The cumulative frequency of all patients with a 50% decrease in proteinuria was 72.78% at 12 months. Sixty (33.3%) patients changed to corticosteroid therapy during the follow-up period. No serious adverse effects were documented during HCQ treatment. HCQ effectively and safely reduces proteinuria in IgAN patients with different levels of eGFR, supporting the maintenance of stable kidney function in the long term.