Study Finds No Increase in Long-Term Renal Survival in Patients with IgA Nephropathy

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A systematic review and meta-analysis found long-term renal survival did increase over the years among patients with IgA neuropathy (IgAN), with survival rates lower in developing countries than other developed countries.¹

In the study, presented at the American Society of Nephrology (ASN) Kidney Week 2023, in Philadelphia, Pennsylvania, there were no significant changes in 3-year and 5-year renal survival in IgAN patients. However, the 10-year renal survival rates gradually decreased over time.

The team of investigators suggested the importance of proteinuria, or elevated protein in the urine, in the long-term prognosis of IgAN. When proteinuria was <1g/24h, the data showed significant improvements in long-term renal survival.

“These results could be used to counsel patients on long-term renal survival and know the trend of survival in developed and developing countries,” wrote the investigative team, led by Huijan Zhang, Sichuan Academy of Medical Sciences and Sichuan People’s Hospital.

IgAN, or Berger’s disease, is a slowly progressing disease that leads to end-stage renal disease in approximately half of diagnosed patients within 25 years of the disease.² Those diagnosed with end-stage renal disease experience higher yearly costs and could endure great financial pressure.

Zhang and colleagues suggested the assessment of trends across renal survival could determine if treatment strategy changes have led to improved long-term renal outcomes.¹ For analysis, the team searched the PubMed, Embase and Cochrane Database for cohort studies and clinical trials on renal survival in patients with IgAN from their inceptions to November 2021.

The outcome was assessed as a composite of any of the listed factors, including doubling of serum creatinine level, a 50% decline in estimated glomerular filtration rate, or end-stage renal disease. Investigators collected data on 3-year, 5-year, and 10-year renal survival in IgAN.

Within the analysis, investigators also assessed the variation in studies from developed countries compared with developing countries. As well, they analyzed the impact of proteinuria on long-term renal survival.

Overall, a total of 146 articles reported on 98,334 patients from 1988 to 2021. Upon analysis, investigators found the 3-year, 5-year, and 10-year renal survival were 94% (95% CI, 94.08 - 94.16%), 89% (95% CI, 88.58 - 88.70%), and 77% (95% CI, 77.34 - 77.59%), respectively.

Over the past few decades, investigators identified a lack of significant changes in 3-year and 5-year renal survival among patients with IgAN. However, 10-year renal survival rates of IgAN have been found to gradually decrease since the 1990s.

This analysis revealed survival in developed countries was higher and fluctuated less than in developing countries. Renal survival was also improved when proteinuria was <1.0 g/24h.

References

1. _{Zhang H. Li G. Long-Term Renal Survival in Patients with IgA Nephropathy: A Systematic Review and Meta-Analysis. Paper presented at: American Society of Nephrology Kidney Week 2023. November 1-5, 2023}
2. _{Huang L, Guo FL, Zhou J, Zhao YJ. IgA nephropathy factors that predict and accelerate progression to end-stage renal disease. Cell Biochem Biophys. 2014;68(3):443-447. doi:10.1007/s12013-013-9741-2}