Mortality in IgA Nephropathy: A Nationwide Population-Based Cohort Study

Area of Science:

• Nephrology
• Epidemiology
• Public Health

Background:

• IgA nephropathy (IgAN) presents a variable clinical course, ranging from asymptomatic to aggressive disease.
• Up to 25% of IgAN patients may develop end-stage renal disease (ESRD) within 20 years.
• Previous studies on IgAN mortality lacked matched controls and absolute risk data.

Purpose of the Study:

• To determine the absolute risk and impact of IgA nephropathy on mortality and ESRD.
• To provide a population-based assessment of IgAN's long-term health consequences.

Main Methods:

• A population-based cohort study in Sweden (1974-2011) using national registers.
• 3,622 biopsy-verified IgAN patients were matched with 18,041 controls.
• Sibling and spousal analyses were also conducted to validate findings.

Main Results:

• IgAN patients experienced a 1.53-fold increased mortality risk (10.67 vs. 7.45 deaths per 1000 person-years).
• This translates to one excess death per 310 person-years and a 6-year reduction in median life expectancy.
• IgAN was associated with one additional ESRD case per 54 person-years.

Conclusions:

• IgA nephropathy significantly increases overall mortality compared to matched controls.
• The disease leads to a substantial reduction in life expectancy.
• IgAN is also a significant contributor to the development of end-stage renal disease.