Understanding the Evidence Gaps in the Epidemiology and Burden of Lupus Nephritis and Membranous Nephropathy: A Targeted Literature Review.

Background: Lupus nephritis (LN) and membranous nephropathy (MN) are associated with progression to chronic kidney disease and end-stage renal disease (ESRD), but evidence describing the full disease burden across countries remains limited and fragmented. Objectives: This targeted literature review (TLR) aimed to characterize the disease burden of LN and MN, including epidemiology and clinical, humanistic, and economic outcomes, and identify unmet needs and current knowledge gaps. Methods: A targeted, nonsystematic search of MEDLINE and EMBASE was conducted for English-language articles published between January 2013 and August 2023 in the United States (US), the United Kingdom, Germany, France, China, and Japan. Results: Searches identified 26 relevant articles for LN and 11 for MN. LN epidemiology studies were limited to the US; incidence was estimated at 1:100 000, with higher risk in older individuals, females, and African Americans. MN is rare, with reported annual incidences of 10 to 12 per million in North America and 2 to 17 per million in Europe. Prevalence appears to be increasing for both diseases. LN was associated with substantial progression to ESRD, with 21.1% to 36.8% of patients progressing within 5 to 10 years. ESRD represented a major economic driver, with US monthly costs of approximately $15 000 per patient with LN. MN burden data were more limited but indicated risk of severe long-term renal complications and ESRD. Humanistic burden data were sparse; reported health-related quality-of-life impacts include renal symptom domains not captured by generic instruments, indicating a need for disease-specific measures. Conclusions: Despite evidence of substantial burden, important gaps remain. Epidemiological data were geographically limited, with incidence varying widely, potentially reflecting differences in populations, treatment eras, and ethnicity. Long-term data beyond 5 to 10 years were limited, and robust syntheses evaluating prognostic factors influencing progression to ESRD were lacking. The absence of renal-specific patient-reported outcome measures and inconsistent clinical definitions further limits comparability and treatment value assessment. LN and MN are associated with significant clinical, economic, and humanistic burden, especially for patients with ESRD, but certainty and generalizability are limited by the focused TLR methods and heterogeneous evidence base. More robust data would help characterize long-term outcomes and support more informed value assessments.