Abstract: SA-PO811
Long-Term Risk and Risk Factors for ESKD in Membranoproliferative Glomerulonephritis
Session Information
- C3G, TMA, MGRS, Amyloidosis, and More
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Bjoerneklett, Rune, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Bostad, Lars Sigurd, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Knoop, Thomas, Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Bostad, Leif Henry, Department of Clinical Medicine, University of Bergen, Bergen, Norway
Background
Membranoproliferative glomerulonephritis (MPGN) is a distinctive light
microscopic injury pattern caused by a wide range of different disease conditions. The
classification of MPGN has changed over time, it is now common to divide MPGN
caused by immune complexes (IC-MPGN) and MPGN caused by dysregulation of the
alternative activation pathway in the complement system, complement C3
nephropathy (C3G). The utility of division by IC-MPGN/C3G versus etiological division
for diagnosis, treatment, and prognosis, however, is still uncertain. There is a need for
more information about the long-term prognosis of MPGN, including risk factors for
progression to end-stage kidney disease (ESKD). We have therefore analyzed the risk of
ESKD for patients with MPGN registered in the Norwegian Kidney Biopsy registry (NKBR)
in the period 1991-2012.
Methods
Cases of biopsy-verified MPGN 1991-2012 including demographic, clinical,
laboratory, and histological variables at the time of diagnosis were retrieved from
NKBR. Cases of MPGN due to SLE and thrombotic microangiopathy were excluded. The
cohort was linked with the Norwegian Kidney Registry for identification of patients with
ESKD by May 1, 2014
Results
We identified 158 patients with biopsy-verified MPGN. Male; 85 (54%), age; 47
years (SD 23), systolic BP; 151mmHg (SD 28), diastolic BP; 86 mmHg (SD 16),
hypertension; 155 (67%), mean eGFR; 50 ml/min/1.73m2 (SD 35), eGFR<15; 18 (11%),
eGFR 15-29; 26 (16%), eGFR 30-59; 49 (31%), s-albumin 28 g/l (SD 7), proteinuria 5.6
g/24h (SD 3.4), nephrotic syndrome; 79 (50%), crescents; 28 (18%), tubulointerstitial
fibrosis >50%; 77 (49%) and C1q positive; 111 (70%). During an average observation
period of 11 years, 61 (39%) of patients progressed to ESKD. 45 (28%) of the patients
died, without ESKD. Cumulative risk for ESKD after 5/10/15/25 y; 25%/37%/43%/48%. A
low eGFR was the only significant risk factor of ESKD, 42 vs 55, p=0.03.
Conclusion
A cumulative long-term risk for ESKD in patients with MPGN of around 50%
corresponds well with previously published studies. The registry data unfortunately
does not allow precise classification by IC-MPGN/C3N. C1q positivity is, however,
indicative of IC-MPGN and in this study not a significant prognostic factor.
Funding
- Commercial Support – Novartis