Coexistence of ANCA-associated glomerulonephritis and membranous nephropathy: a scoping review.

BACKGROUND

Coexistence of anti-neutrophil cytoplasmic antibody -associated glomerulonephritis (ANCA-GN) and membranous nephropathy (MN) is rare. This scoping review mapped evidence on clinicopathologic features, phenotypic heterogeneity, and reporting gaps relevant to future rigorous phenotype-specific comparative studies.

METHODS

Comprehensive searches of PubMed, Web of Science, and CENTRAL from inception to April 16, 2026 identified original studies of patients with coexisting ANCA-GN and MN. Two reviewers independently extracted study and participant characteristics, renal and systemic findings, serologic and antigen data, associated conditions, treatments, outcomes, phenotype categories, and temporal relationships. Individual-level cases were assigned using a prespecified phenotype framework.

RESULTS

Seventy studies (140 patients) were included, comprising 113 individually charted cases and one aggregate-only cohort of 27 patients. Among individual-level cases, median age was 60 years; median serum creatinine, 2.75 mg/dL; and median proteinuria, 3.7 g/day or g/g creatinine (g/gCr). The overlap was phenotypically heterogeneous, including 66 likely myeloperoxidase (MPO)-associated/ANCA-GN-related cases, 10 likely primary-MN-like overlap cases, 31 secondary/associated cases, and 6 unclassifiable cases. Temporal relationship was ascertainable for all 113 cases: 101 (89.4%) had concurrent onset (≤ 6 months), 7 (6.2%) had MN preceding ANCA-GN, and 5 (4.4%) had ANCA positivity preceding MN. The evidence base was constrained by case-report predominance, selective antigen testing, sparse longitudinal biomarker/follow-up data, and nonuniform outcome reporting.

CONCLUSIONS

Coexisting ANCA-GN and MN is a rare, clinically important, and heterogeneous spectrum rather than a single pooled entity. Future studies should use phenotype-specific designs with standardized antigen testing, crescent reporting, longitudinal ANCA assessment, consistent outcome definitions, and explicit follow-up.