Immunoadsorption in Anti-glomerular Basement Membrane Glomerulonephritis; a Pilot Study

Rationale: Anti-glomerular basement membrane (anti-GBM) glomerulonephritis is a rare organ-specific autoimmune disease that is mediated by anti-GBM antibodies. It is characterized by acute renal failure due to diffuse crescentic glomerulonephritis, often accompanied by pulmonary hemorrhage. Established treatment is cyclophosphamide and corticosteroids to suppress anti-GBM production and daily plasma exchange to remove circulating anti-GBM antibodies. The vast majority of patients with anti-GBM glomerulonephritis develop irreversible end-stage renal failure despite this treatment. The treatment goal in anti-GBM glomerulonephritis is to achieve undetectable anti-GBM titres as rapid as possible. Immunoadsorption is an extracorporeal technique that selectively removes antibodies and may lower anti-GBM titres more effectively than plasma exchange. With this technique the patient's plasma is passed through an immunoadsorption column that contains protein A that binds antibodies of the IgG class like anti-GBM antibodies. However, data on the efficacy of anti-GBM removal by immunoadsorption compared with plasma exchange are scarce. In the literature, there are only a few case descriptions of the clinical effect of immunoadsorption in patients with anti-GBM disease with some cases showing recovery of renal function despite unfavourable prognosis (serum creatinine >500 µmol/l and/or high percentage of crescents on renal biopsy). Immunoadsorption is presently not used in the Netherlands for anti-GBM disease.

Objective: To study the efficacy, adverse events, logistic feasibility and costs of immuno-adsorption for the removal of anti-GBM antibodies in patients with acute renal failure due to anti-GBM glomerulonephritis.

Study design: Interventional, open, non-randomized, pilot study. After informed consent, patients will be treated according to the current treatment protocol with the exception of daily immunoadsorption instead of daily plasma exchange.

Study population: 8 patients with acute renal failure due to anti-GBM glomerulonephritis with or without accompanying pulmonary involvement.

Intervention: Participating patients will be treated with daily immunoadsorption (2.5 times the plasma volume), instead of plasma exchange, until anti-GBM titres are undetectable. All other aspects of the treatment (e.g. immunosuppressive treatment, renal replacement therapy) will be standard.