Study Compares Pulse and Oral Corticosteroid Therapy for IgA Nephropathy

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Corticosteroid pulse therapy demonstrated superior safety and efficacy compared to oral corticosteroid therapy for the treatment of immunoglobulin A (IgA) nephropathy in a retrospective study.

Results of the study, which included more than 190 patients with IgA nephropathy, indicated corticosteroid pulse therapy may be more effective for reducing urinary protein levels and improving renal function with a lower incidence of adverse events.¹

“Based on the pathogenesis of IgA nephropathy, many emerging treatment approaches and trials are ongoing, but there is currently no uniform treatment for IgA nephropathy,” wrote investigators.¹ “Corticosteroid treatments mainly include oral corticosteroid therapy and corticosteroid pulse therapy. However, there are few reports on the efficacy and safety of these two treatments.”

A chronic kidney disease leading to end-stage renal disease, IgA nephropathy is caused by deposits of IgA inside glomeruli in the kidney preventing filtration of waste and excess water. Corticosteroids are frequently used to treat IgA nephropathy and slow the process of kidney damage by reducing inflammation and scar tissue.²

To compare the safety and efficacy of oral corticosteroid therapy and corticosteroid pulse therapy, Qinghua Liu, MD, PhD, associate professor of nephrology at The First Affiliated Hospital of Sun Yat-sen University in China, and a team of investigators retrospectively assessed urine protein level, renal function, and adverse events for patients diagnosed with IgA nephropathy between May 2013 and October 2020 at the First Affiliated Hospital of Sun Yat-sen University. To be included in the study, patients were required to be ≥ 14 years of age and have an estimated glomerular filtration rate >15 mL/min/1.73m2, 24h urine protein level >0.75 g and <3.5 g, no corticosteroids or immunosuppressive therapy before renal biopsy, and clinical and pathological data with at least 3-months of follow-up data.¹

In total, investigators enrolled 192 patients who were 49% male and had a mean age of 33.26 years. Among the cohort, 120 participants were treated with oral corticosteroid therapy and 72 were treated with corticosteroid pulse therapy. Although investigators noted most baseline characteristics were similar between the groups, the oral corticosteroid group had significantly higher age, mean arterial pressure, serum creatinine level, serum uric acid level, total cholesterol level, and 24 h urine protein level but lower initial estimated glomerular filtration rate and ratio of renin-angiotensin system blocker use (all P < .05). The corticosteroid pulse group also had a lower ratio of T1/2 (P = .001) but a higher ratio of C1/2 (P = .046) and a higher crescent proportion (P = .031).¹

Investigators evaluated treatment efficacy based on patients’ urine protein level and renal function at the time of their last follow-up visit. Complete remission was defined as 24h urine protein level <0.4 g and stable renal function with a <30% decline in estimated glomerular filtration rate from baseline. Partial remission was defined as 24h urine protein level declines ≥50% and ≥0.4 g, stable renal function with a <30% decline in estimated glomerular filtration rate from baseline. The study endpoint was the first occurrence of a 40% decrease in estimated glomerular filtration rate, the development of end-stage renal disease, or death due to kidney disease.¹

After treatment, investigators noted the complete remission rate and total remission rate were significantly improved in the corticosteroid pulse group compared to the oral corticosteroid group (P < .05). Further analysis revealed the probability of achieving total remission was significantly greater in the corticosteroid pulse group compared to the oral corticosteroid group (odds ratio [OR], 2.509; 95% confidence interval [CI], 1.171–5.377; P = .018). Investigators pointed out there were more end-point events in the oral corticosteroid group (16.7%) than in the corticosteroid pulse group (4.2%; P = .010).¹

To better compare outcomes in both groups, investigators used propensity score matching to assign 47 patients in the corticosteroid pulse therapy group to 47 patients in the oral corticosteroid therapy group. Age, sex, creatinine, glomerular filtration rate, 24h urine protein level, mean arterial pressure, pathological classification, the use of renin-angiotensin system blockers, and follow-up time were included as covariates in the model.¹

After matching, there were no significant differences in the baseline data between the 2 groups (P > .05), while the complete remission rate remained higher in the corticosteroid pulse group than in the oral corticosteroid group (P < .05). Subgroup analysis showed the corticosteroid pulse therapy group was more likely to achieve remission in patients with initial 24-h urine protein levels falling into the range of 2–3.5 g and Oxford Classification of S1 or C1/2 (P < .05).¹

During treatment, investigators noted the incidence of adverse events and infections in the oral corticosteroid group was higher than that in the corticosteroid pulse therapy group (84.1% vs 51.4%, p < 0.001, and 48.9% vs. 32.9%, p = 0.043, respectively). After propensity score matching, the incidence of overall adverse events in the oral corticosteroid group (86.7%) was also higher than that in the corticosteroid pulse group (57.8%; P = .008), but there was no significant difference in the incidence of infection events between the two treatment groups (46.7% vs 44.4%, respectively; P = .850).¹

“For IgA nephropathy with a 24-h urine protein level of 0.75–3.5 g, compared with oral corticosteroid therapy, corticosteroid pulse therapy may be more effective in reducing proteinuria and improving renal function with a lower incidence of adverse events,” concluded investigators.¹

References:

1. Wang Y, Huang N, Wang Y, et al. Comparative analysis between the safety and efficacy of oral corticosteroids versus corticosteroids pulse therapies in IgA nephropathy. Renal Failure. 45:2. doi:10.1080/0886022X.2023.2255683
2. Johns Hopkins Medicine. Immunoglobulin A (IgA) Nephropathy. Conditions and Diseases. Accessed October 11, 2023. https://www.hopkinsmedicine.org/health/conditions-and-diseases/immunoglobulin-a-iga-nephropathy