G MCDONALD1, L ANDERSON2,3, D GRACEY1,3
1Department of Renal Medicine, Royal Prince Alfred Hospital, Australia, 2Department of Tissue Pathology and Diagnostic Oncology, Royal Prince Alfred Hospital, Australia, 3Central Clinical School, Faculty of Medicine and Health, University of Sydney, Australia
Background
Idiopathic nodular glomerulosclerosis (ING) is a rare condition typically seen in elderly Caucasian males and is associated with hypertension, smoking, obesity and hypercholesterolaemia. It classically presents with renal dysfunction and nephrotic range proteinuria. Histologically it’s virtually indistinguishable from diabetic glomerulosclerosis and exclusion of diabetes mellitus is required. We present an unusual case of ING with no history of smoking and rapid progression of renal impairment despite a paucity of predictors for end-stage disease.
Case Report
An 89-year-old man with a longstanding history of untreated hypertension and hypercholesterolaemia was referred for investigation of declining renal function over a 3-year period. He was subsequently found to have microscopic haematuria and nephrotic-range proteinuria. The blood pressure was 200/85mmHg despite Telmisartan 80mg and Indapamide 1.5mg daily. Body mass index was 31.5kg/m2.
Investigations showed a serum creatinine (sCr) 193umol/L and estimated glomerular filtration rate (eGFR) 25ml/min, from sCr 137umol/L, eGFR 39ml/min seven months prior. The 24-hour urinary protein excretion was 3596mg. Computed tomography-intravenous pyelogram to investigate microhaematuria was normal. Autoimmune screen and serum electrophoresis were unremarkable. The haemoglobin A1c was 5.4% with a fasting blood sugar level of 4.8mmol/L.
Thirteen glomeruli were seen on biopsy, 4 were globally sclerosed. Light microscopy showed nodular Periodic acid-Schiff positive expansion of mesangium with peripherally displaced nuclei – Kimmelstiel Wilson-like nodules. Moderate interstitial fibrosis and tubular atrophy was present. Immunofluorescence was negative. Electron microscopy showed thickened glomerular basement membranes with mild foot process effacement and mild arteriosclerosis.
Conclusions
ING is an uncommon condition; it is important that clinicians can recognise it and manage modifiable risk factors for progression. This atypical case of ING contributes to our limited knowledge of the disorder.
Biography:
Georgina McDonald is a renal advanced trainee in the Central South West Regional network within New South Wales.