Abstract: The present invention provides IdeS polypeptide for use in a method of treating or pre-venting a disease mediated by pathogenic polymeric IgA complexes. wherein said dis-ease or disorder is progressive IgA nephropathy (IgAN) or recurrent IgAN following re-nal transplantation. The IdeS polypeptides finds particular use in induction therapy of progressive or recurrent IgAN disease or disorder.

Abstract: The invention provides the use of a glucocorticoid having a first pass metabolism in the liver of at least 90% as active substance, for the manufacturing of a medicament for oral or rectal administration in the treatment of glomerulonephritis by releasing the active substance in the intestine. The invention also provides a method for treatment of glomerulonephritis in a native kidney or a kidney transplant with the glucocorticoid as defined above. The invention also comprises a composition comprising the active substance and a pharmaceutically acceptable carrier, adjuvant or diluent designed for oral or rectal administration.