Study Details Characteristics, Risk of Disease Progression in Patients with IgAN

Nearly half of patients with immunoglobulin A nephropathy (IgAN) receiving supportive care remained at high risk of progression after 6 months, according to findings from a retrospective cohort study.

Results also highlighted the prevalence of advanced kidney disease, with more than 60% of participants having ≥ stage 3 chronic kidney disease (CKD) at index, and comorbidities, including hypertension and type 2 diabetes.¹

“IgAN is a complement-mediated kidney disease with a highly variable risk of disease progression; some patients already exhibit loss of kidney function at diagnosis,” wrote investigators.¹ “This analysis described the demographic and clinical characteristics of patients with IgAN in the US and estimated the proportion of patients at high risk of IgAN progression despite treatment with supportive care.”

An important cause of chronic kidney disease and kidney failure, IgAN is found in about 1 in 10 kidney biopsies in the US. Common complications include hypertension, heart disease, stroke, nephrotic syndrome, and eventual kidney failure. There is no cure for IgAN, although treatment may help prevent or delay kidney damage. Disease progression varies from patient to patient, but understanding the clinical and demographic characteristics of patients affected by IgAN can help provide a more comprehensive overview of its impacts.²

Briana Ndife, MPH, of Novartis Pharmaceuticals, and colleagues collected electronic medical records, claims, and lab data for patients with IgAN aged ≥12 years from the HealthVerity database. Demographic and clinical characteristics of patients who had been in the database for ≥12 months continuously before the date of their first IgAN SNOMED diagnosis code were included in the study.¹

Investigators defined high risk of IgAN progression as proteinuria ≥1.0 g/g despite receiving supportive care, involving ≥1 record of angiotensin-converting enzyme (ACE) inhibitors and/or angiotensin 2 receptor blockers (ARBs) within 12 months of the index date, and/or SGLT-2 inhibitors.¹

In total, 1,541 patients with IgAN were included in the study. Among the cohort, the mean age was 43.8 (Standard deviation [SD], 14.5) years and 53% of participants were male. Of 918 patients with available data, 62.1% had stage ≥3 CKD at index. Mean eGFR was 67 (SD, 33) mL/min/1.73m2 and mean proteinuria was 1.9 (SD, 1.9) g/g.¹

Overall, 1.8% of patients had previously undergone a kidney transplant. Investigators pointed out comorbidities including hypertension (62.5%) and type 2 diabetes (13.8%) were common, as was treatment with ACE inhibitors or ARBs within 12 months post-index (52.8%). The proportion of patients investigators identified as being at high risk of IgAN progression despite supportive care at 6 months post-index was 46/109 (42.2%) compared to 32/95 (33.7%) at 12 months post-index.¹

“In a cohort of patients with IgAN using real-world EMR and administrative claims data, comorbidities and advanced kidney disease were common. About half of these patients were receiving ACE inhibitors or ARBs (with or without SGLT-2 inhibitors) within 12 months after diagnosis, and half remained at high risk of progression at 6 months. These data highlight the need for novel therapies in IgAN,” investigators concluded.¹

References:

1. Ndife BC, Aldworth CAR, Nguyen J, et al. Clinical Burden of IgA Nephropathy (IgAN) in the United States: A Retrospective Electronic Medical Record (EMR) and Claims Analysis. Paper Presented at: American Society of Nephrology Kidney Week 2023. November 1-5, 2023.
2. National Institute of Diabetes and Digestive and Kidney Diseases. IgA Nephropathy. Health Information. September 2022. Accessed November 16, 2023. https://www.niddk.nih.gov/health-information/kidney-disease/iga-nephropathy