IgG4-related disease and idiopathic membranous nephropathy: "The clothes do not make the man" .

This case report describes a patient with a previous history of autoimmune pancreatitis secondary to IgG4-related disease, who developed an overt nephrotic syndrome due to membranous nephropathy, surprisingly idiopathic. In all the previously described cases with both concurrent diseases, membranous nephropathy was considered to be secondary to the IgG4-related disease based on the absence of anti-PLA2R1 autoantibodies, and nephrotic syndrome usually remitted after treatment with steroids alone. However, in our patient positivity of serum anti-PLA2R1 autoantibodies together with a normal serum IgG4 level, and the absence of the other most commonly associated diseases were compatible with an idiopathic membranous nephropathy.

Glomerular C3d as a novel prognostic marker for renal vasculitis.

Pauci-immune necrotizing crescentic glomerulonephritis is the histologic substrate of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. Several studies in animal models have demonstrated the crucial role of complement activation in the pathogenesis of ANCA-associated vasculitis, but only small series have analyzed the prognostic implications of complement glomerular deposits. This study aimed to assess the clinical and prognostic implications of C3d- and C4d-positive glomerular staining in renal vasculitis.

The predictive value of kidney biopsy in renal vasculitis: a multicenter cohort study.

The histopathologic classification of antineutrophil cytoplasmic antibody-associated vasculitis has been demonstrated to have prognostic value in small cohorts of patients with pauci-immune extracapillary glomerulonephritis. We aimed to validate this histologic subgrouping system in a large cohort of patients with renal vasculitis from 3 Spanish centers. The additional value of several histologic parameters for predicting renal outcome was investigated.