The natural history of IgM nephropathy in adults
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Background: Immunoglobulin M (IgM) nephropathy is an idiopathic glomerulonephritis characterised by diffuse mesangial deposition of IgM. IgM nephropathy has been a controversial diagnosis since it was first reported, and there are few data identifying specific pathological features that predict risk of progression of renal disease.
Methods: We identified 57 cases of IgM nephropathy among 3220 adults undergoing renal biopsy at our institution. Biopsies had to satisfy the following three criteria to meet the definition of IgM nephropathy in this study: (1) dominant mesangial staining for IgM, (2) mesangial deposits on EM, (3) exclusion of systemic disease.
Results: The median age was 42 years and 24 patients were male. 39% of patients presented with the nephrotic syndrome, 49% patients presented with non-nephrotic proteinuria, and 39% had eGFR <60 ml/min. Median post-biopsy follow-up was 40 months and serum creatinine had doubled in 31% by 5 years. Of histological parameters, glomerular sclerosis and tubular atrophy, but not mesangial proliferation, were risk factors for renal insufficiency. 39% of nephrotic patients achieved complete remission, and outcome was significantly worse in those who did not respond to treatment. FSGS was diagnosed in 80% of those undergoing repeat renal biopsy, despite ongoing mesangial IgM deposition.
Conclusions: We propose criteria for a consensus definition of IgM nephropathy.
Methods: We identified 57 cases of IgM nephropathy among 3220 adults undergoing renal biopsy at our institution. Biopsies had to satisfy the following three criteria to meet the definition of IgM nephropathy in this study: (1) dominant mesangial staining for IgM, (2) mesangial deposits on EM, (3) exclusion of systemic disease.
Results: The median age was 42 years and 24 patients were male. 39% of patients presented with the nephrotic syndrome, 49% patients presented with non-nephrotic proteinuria, and 39% had eGFR <60 ml/min. Median post-biopsy follow-up was 40 months and serum creatinine had doubled in 31% by 5 years. Of histological parameters, glomerular sclerosis and tubular atrophy, but not mesangial proliferation, were risk factors for renal insufficiency. 39% of nephrotic patients achieved complete remission, and outcome was significantly worse in those who did not respond to treatment. FSGS was diagnosed in 80% of those undergoing repeat renal biopsy, despite ongoing mesangial IgM deposition.
Conclusions: We propose criteria for a consensus definition of IgM nephropathy.
Date Acceptance
2016-03-01
Citation
Nephrology Dialysis Transplantation
ISSN
1460-2385
Publisher
Oxford University Press (OUP)
Journal / Book Title
Nephrology Dialysis Transplantation
Copyright Statement
© 2016 Oxford University Press. This paper is embargoed until published, then subsequently subject to a 12 months embargo.
Sponsor
Imperial College Healthcare NHS Trust- BRC Funding
Grant Number
RDA04 79560
Subjects
Urology & Nephrology
Clinical Sciences
Publication Status
Accepted