Socioeconomically Deprived Patients with IgAN Face Worse Kidney Outcomes

Jonathan Barratt, MD

Credit: IgA Nephropathy Foundation

Socioeconomic deprivation is associated with worse kidney outcomes in patients with immunoglobin A nephropathy (IgAN), according to findings from a recent study.

Results showed patients with greater socioeconomic deprivation were at an increased risk of faster progression of kidney failure compared to patients in the least deprived Index of Multiple Deprivation (IMD) quintile.¹

“Given the well established gradient between greater socioeconomic deprivation and worse health, in this study we aimed to determine whether socioeconomic deprivation influenced the risk of developing kidney failure in IgAN,” wrote investigators.¹

A kidney disease causing immunoglobulin A buildup, IgAN leads to inflammation making it harder for the kidneys to filter waste from the blood and eventually progressing to kidney failure. Treatment seeks to slow this process, although not all patients respond to treatment or have access to it. Socioeconomic deprivation is associated with worse health outcomes, although its specific impact on kidney failure in IgAN has not been explored.^2,1

To assess the impact of socioeconomic deprivation on the risk of developing kidney failure among patients with IgAN, Jonathan Barratt, MD, Mayer Professor of Renal Medicine at the University of Leicester, and colleagues collected data from the UK National Registry of Rare Kidney Diseases (RaDaR), classified them into deprivation quintiles based on patient postcodes matched to IMD scores, and assessed kidney survival from diagnosis.¹

RaDaR recruits adults and children with biopsy-proven primary IgAN and estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2 or proteinuria ≥0.5g/24h from 107 adult and pediatric kidney units across the United Kingdom. In the present study, 4,127 RaDaR participants were enrolled and followed until the initiation of kidney replacement therapy censored for death. Investigators used Kaplan Meier methods and Cox regression to assess kidney survival from diagnosis and compare it to patients’ deprivation quintile.¹

Among patients in IMD quartile 1, labeled as the most deprived, the median age was 38.9 years, 67.3% were male, and 75.2% were white. In IMD quartiles 3 and 5, patients were older (41.0 and 41.6 years of age, respectively), a greater proportion was male (69.9% and 74.3%, respectively), and more patients were white (86.2% and 88.5%, respectively).¹

Upon analysis, patients in IMD quartile 1 exhibited the shortest length of time to kidney failure (7.9 years; 95% confidence interval [CI], 6.9-9.3). Patients in IMD quartile 3 showed a slightly longer length of time to kidney failure (10.4 years; 95% CI, 9.0-12.6), but patients in IMD quartile 5 had the longest period between diagnosis and kidney failure (12.4 years; 95% CI, 11.1-13.5).¹

Investigators made note of an association between the risk of developing kidney failure and deprivation quintile, pointing out the most deprived IgAN patient group exhibited significantly faster progression compared to their less-deprived counterparts. After adjusting for age, eGFR at diagnosis, and gender for IMD quartiles 1 and 3, the hazard ratio was 1.4 (CI, 1.15-1.84; P =.0017).¹

“Outcomes in this large IgAN cohort have been published and shown to be poor with few patients expected to avoid kidney failure in their lifetime. This analysis demonstrates even worse outcomes if more socioeconomically deprived and highlights the need to develop strategies to ensure equity of access not only to early diagnosis but also to the new therapies that are showing promise in preventing kidney failure in IgAN,” concluded investigators.¹

References:

1. Barratt J, Pitcher D, Wong K, et al. Levels of Socioeconomic Deprivation Are Associated with Worse Kidney Outcomes in Patients with IgA Nephropathy: Data from UK RaDaR. Paper Presented at: American Society of Nephrology Kidney Week 2023. November 1-5, 2023.
2. Mayo Clinic. IgA nephropathy (Berger disease). Diseases & Conditions. June 9, 2023. Accessed November 16, 2023. https://www.mayoclinic.org/diseases-conditions/iga-nephropathy/symptoms-causes/syc-20352268