Idiopathic Nodular Glomerulopathy



Idiopathic Nodular Glomerulopathy


A. Brad Farris, III, MD










In ING, glomeruli have nodular mesangial expansion, hypertrophy, & hypercellularity incidentally found in a nephrectomy for tumor in a 63-year-old woman with no history of diabetes.






In a case of ING, there is a relatively acellular glomerular nodule image. Glomerular basement membranes image are possibly only segmentally thickened with no duplication.


TERMINOLOGY


Abbreviations



  • Idiopathic nodular glomerulopathy (ING)/glomerulosclerosis (GS)


Synonyms



  • Smoking-associated nodular GS


  • Idiopathic lobular glomerulonephritis


  • Nodular mesangial sclerosis


Definitions



  • Nodular GS, associated with smoking &/or hypertension (HTN) without history of diabetes mellitus (DM)


ETIOLOGY/PATHOGENESIS


Environmental Exposure



  • Smoking



    • Leads to microalbuminuria in healthy individuals


    • Risk factor for renal dysfunction


    • Advanced glycation end products (AGE) formation, oxidative stress, angiogenesis, & altered intrarenal hemodynamics



      • AGE alters extracellular matrix (ECM) by protein crosslinking and interaction with cell surface receptors such as receptor to AGE (RAGE)


      • Mediators include NF-κB, MAPK, JAK/STAT, Smad, TGF-β, IGF, VEGF, fibrogenic cytokines, PDGF, type IV collagen, laminin, heparan sulfate, & fibronectin


    • Chronic obstructive pulmonary disease (COPD)



      • Activates sympathetic & renin-angiotensin systems, leading to HTN & ECM production


Hypertension



  • Smoking-induced renal injury probably more likely with preexisting sclerotic insult, such as hypertensive nephrosclerosis


  • ING has been reported with only history of HTN in absence of smoking


CLINICAL ISSUES


Epidemiology



  • Age



    • Elderly


  • Gender



    • Male predominance a feature of most series


  • Ethnicity



    • White predominance noted in larger series


Presentation



  • Renal dysfunction (˜ 80% of patients)


  • Proteinuria, nephrotic range (˜ 70% of patients)


Treatment



  • Drugs



    • Angiotensin II blockade


Prognosis



  • ESRD has been noted



    • 35.3% over 14.2-month period in 1 series


MICROSCOPIC PATHOLOGY


Histologic Features

Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Idiopathic Nodular Glomerulopathy

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