IgAN Among Most Common Primary Glomerular Diseases Requiring Kidney Replacement Therapy

Samar Abd ElHafeez

Credit: Frontiers

Findings from a recent European Renal Association (ERA) Registry study are providing an overview of trends in the incidence of kidney replacement therapy (KRT) for primary glomerular disease-induced kidney failure, calling attention to an increased and growing KRT incidence for patients with IgA nephropathy (IgAN).¹

Although the overall incidence rate of KRT for end-stage kidney disease (ESKD) due to primary glomerular disease was 16.6 per million population (pmp), the standardized incidence varied significantly from 8.6 pmp to 20.0 pmp between countries and was greatest for IgAN and focal segmental glomerulosclerosis (FSGS).¹

“Studying the incidence and outcomes of KRT due to kidney failure for various [primary glomerular disease] subgroups helps in understanding their prognosis, which could contribute to the development of a more individualized and equitable patient care approach,” wrote Samar Abd ElHafeez, associate professor in the epidemiology department at Alexandria University in Egypt, and colleagues.¹

Renal replacement therapy replaces nonendocrine kidney function in patients with renal failure, exchanging solute and removing fluid from the blood using dialysis and filtration across permeable membranes. A common form of glomerulonephritis, IgAN is one of the leading causes of renal failure, although several other primary glomerular diseases can also lead to renal failure requiring KRT. Information about the incidence and outcomes of KRT in these patients is sparse, leading to a poor understanding of their prognosis.^2,3

To provide a more comprehensive overview of the incidence of KRT for ESKD due to primary glomerular disease, investigators collected data for 69,854 patients between 2000 and 2019 from 32 renal registries in the ERA Registry. ERA primary renal disease codes were used to define 6 primary glomerular disease subgroups: IgAN, membranoproliferative glomerulonephritis (MPGN), membranous nephropathy (MN), FSGS, crescentic glomerulonephritis (GN), and other primary glomerular diseases.¹

Investigators calculated the crude incidence pmp by dividing the number of patients starting KRT by the mid-year general population of the country or region, multiplied by 1 million. The standardized incidence was calculated using the age and sex distribution of the EU28 of 2015 as a reference.¹

Among the patients who commenced KRT due to primary glomerular disease-induced kidney failure, 19,394 (27.8%) had a diagnosis of IgAN, 11,016 (15.8%) had FSGS, 5,914 (8.5%) had MPGN, 4,079 (5.8%) had crescentic GN, and 3,133 (4.5%) had MN. The remaining 26,318 (37.7%) patients were categorized as “other PGD.” The median at the onset of KRT was 58.5 (Interquartile range [IQR], 44.5 to 70.6) years and 68.9% of patients were male.¹

Upon analysis, the standardized incidence of KRT for ESKD was 16.6 pmp, ranging from 8.6 pmp in Serbia to 20.0 pmp in France. Of note, IgAN and FSGS had the highest incidence of 4.6 pmp and 2.6 pmp, respectively.¹

The crude incidence of KRT was lowest in the age group 0-19 years (1.4 pmp) and highest in the age group 65-74 years (35.9 pmp), additionally affecting males (22.4 pmp) more than females (9.7 pmp).¹

Investigators pointed out the overall incidence declined from 18.6 pmp in 2000 to 14.5 pmp in 2013 (average percentage change [APC], -1.8; 95% CI, -2.2 to -1.4), after which it stabilized. Among the disease subgroups, the standardized incidence of KRT increased between 2012 and 2019 for IgAN (APC, 5.1; 95% CI, 2.7 to 7.6) and between 2000 and 2019 for FSGS (APC, 3.1; 95% CI, 2.3 to 3.8).¹

The crude and adjusted 5-year survival probabilities after the onset of KRT were 71.5% and 69.7%, respectively, with cardiovascular disease identified as the most common cause of death (33.9%). Among the disease subgroups, the crude and adjusted 5-year survival probabilities after KRT initiation were lowest for crescentic GN (57.0% and 64.5%, respectively) and highest for IgAN (83.5% and 76.1%, respectively). Of note, all primary glomerular disease subgroups had 5-year survival probabilities > 50%.¹

“The recognition of the incidence and prognosis of KRT among different [primary glomerular disease] subgroups enables a more personalized approach to patient care. Future studies are warranted to assess the impact of novel therapies on disease progression and the initiation of KRT in [primary glomerular disease] patients,” investigators concluded.¹

References:

1. ^{ElHafeez SA, Kramer A, Arici M, et al. Incidence and outcomes of kidney replacement therapy for end-stage kidney disease due to primary glomerular disease in Europe: findings from the ERA Registry, Nephrology Dialysis Transplantation. https://doi.org/10.1093/ndt/gfae034}
2. ^{University of Florida Health. Renal Replacement Therapy. Patient Care. Accessed February 16, 2024. https://nephrology.medicine.ufl.edu/patient-care/renal-replacement-therpay}
3. ^{Rawla P, Limaiem F, Hashmi MF. IgA Nephropathy (Berger Disease). National Library of Medicine. July 7, 2023. Accessed February 16, 2024. https://www.ncbi.nlm.nih.gov/books/NBK538214/}