Inhibition of tumour necrosis factor alpha in idiopathic membranous nephropathy: a pilot study

Background. Tumour necrosis alpha has been implicated in the pathogenesis of autoimmune disorders was to evaluate the safety, tolerability and potential efficacy of the tumour necrosis factor alpha (TNF-α) inhibitor, etanercept (ET), in patients with idiopathic membranous nephropathy (MN). Methods. Patients with biopsy-proven MN, nephroticrange proteinuria and clearance of creatinine 50 ml/min or more were included in the study. Exclusion criteria were treatment with steroids or cyclosporine during the previous 3 months, or cytotoxic agents within 6 months prior to entry. ET was administered subcutaneously, 25 mg twice per week for 3 months. Plasma levels of TNF-α, interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-10 (IL-10), soluble intercellular adhesion molecule type 1 (sICAM-1), E-selectin, and the soluble form of tumour necrosis factor receptor-55 (sTNFR-55) were measured on entry and at Months 3, 6, and 9 after commencing therapy. Results. Twelve patients were entered in the study (four females/eight males, mean time from diagnosis 8.3 months). The therapy was well tolerated; no infections or other adverse events were recorded by the end of follow-up. Two patients exhibited complete remission of proteinuria for at least 4 years. No significant change was found in the levels of TNF-α, IL-1, IL-6, IL-8 and IL-10 during the study. Similarly the levels of E-selectin and sICAM-1 were not significantly altered by therapy. Although we found no change in sTNFR-55 at 3 and 6 months, the levels of sTNFR-55 were found significantly decreased 9 months after therapy (mean difference from baseline: 334 ± 527 pg/ml, P = 0.028). Conclusion. Short-term use of ET in a small series of patients reduced sTNFR-55 levels but did not exhibit any significant clinical effect in the majority of patients.