AUTHOR=Capecchi Riccardo , Giannese Domenico , Moriconi Diego , Bonadio Angelo G. , Pratesi Federico , Croia Cristina , Egidi Maria F. , Puxeddu Ilaria , Tavoni Antonio G. , Migliorini Paola TITLE=Renal Involvement in IgG4-Related Disease: From Sunlight to Twilight JOURNAL=Frontiers in Medicine VOLUME=8 YEAR=2021 URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2021.635706 DOI=10.3389/fmed.2021.635706 ISSN=2296-858X ABSTRACT=

IgG4-Related Disease (IgG4-RD) is a fibroinflammatory condition characterized by a typical histopathological pattern (dense lymphoplasmacytic infiltrate with prevalent IgG4+ plasma cells and storiform fibrosis), which may involve the kidney both directly (IgG4-related kidney disease, IgG4-RKD) or indirectly, as a consequence of post-renal ureteral obstruction due to retroperitoneal fibrosis (IgG4-RD RF). The most frequent presentation of IgG4-RKD is IgG4-related tubulointerstitial nephritis (TIN), but a glomerular disease can be present, in most of the cases a membranous nephropathy. Albeit steroid-responsive, in some cases renal manifestations may lead to progressive and permanent organ damage. In this review we describe four clinical cases representative of typical and less typical renal manifestations of IgG4-RD, emphasizing a potential, subclinical, early involvement of the kidney in the disease.