OBJECTIVES : IgAN is a rare autoimmune proliferative glomerulonephritis, the hallmark of which is IgA immune complex deposition in the glomerular mesangium. The immune complexes derive from autoantibodies binding to circulating immunogenic galactose-deficient IgA1 antibodies produced mainly in the ileum. While the burden of kidney disease overall is well established, we sought to understand the burden of illness (BOI) and summarize value drivers specifically in IgAN as patients progress through stages of chronic kidney disease, with a focus on US studies.

METHODS : Using PRISMA guidelines and PICOS criteria (Population, Intervention, Comparators, Outcomes, Study design), EMBASE, MEDLINE, and Cochrane databases (2010−6/26/2020) and relevant congress abstracts (2017 to 2020) were searched to identify real-world evidence on IgAN.

RESULTS : Two systematic literature reviews in IgAN were conducted, covering BOI and epidemiology. Of the extracted studies (11 for BOI; 123 for epidemiology), 8 reported quality of life (QoL) results, 31 reported the rate of transition to end-stage renal disease (ESRD), 16 reported mortality, and 24 described treatment patterns in IgAN. While data on symptom burden were limited, fatigue and pain were identified as the main symptoms impacting QoL. Among 4 US studies, progression to ESRD after 3 to 4 years of follow-up occurred in 12.5% to 45% of patients. In one US study with a mean follow-up of 19 years, over half (53%) of patients ultimately developed ESRD, which necessitates dialysis or transplant; renal survival was 60% at 10 years, declining to 50% at 18 years. Life expectancy among those with IgAN in the same US study was 10.1 years lower vs those without IgAN, with 83% of deaths occurring after progression to ESRD.

CONCLUSIONS : Over half of patients with IgAN eventually progress to ESRD, with impacts on QoL and reduced life expectancy. Delaying progression to ESRD is a major value driver to IgAN patients and healthcare systems.