The other end of spectrum in hypertension: ‘Idiopathic nodular glomerulosclerosis’

Abstract

Dear Editor,Nodular glomerulosclerosis is observed in diabetes mellitus, dysproteinemias, lobular membranoproliferative glomerulonephritis, glomerular deposition disease, and chronic hypoxic states. Idiopathic nodular glomerulosclerosis (ING), which is a rare clinical entity, is diagnosed in the absence of these conditions. We report a case of ING in an elderly hypertensive lady.An 82-year-old woman was evaluated for chronic kidney disease. Her medical history included hypertension, permanent atrial fibrillation, and osteoarthritis. There was no personal or family history of diabetes mellitus, hepatitis, autoimmune, or connective tissue disease. She did not use any over-the-counter medications, herbal remedies, cigarettes, alcohol, or recreational drugs. On examination, her vitals revealed blood pressure of 140/93 mmHg, with an irregular heart rate of 74-86 beats/min. The rest of the physical examination was unremarkable. Laboratory parameters were significant for mild normocytic anemia with a hemoglobin level of 10.2 mg/dl, BUN of 65 mg/dl, and creatinine level of 1.7 mg/dl. Fasting blood glucose, 2-h glucose tolerance test, autoantibody screening, complements, hepatitis serology, and cryoglobulins were normal. Urinalysis was normal with random protein 18 mg/dl and creatinine 59.2 mg/dl. Serum protein electrophoresis confirmed by immunofixation revealed monoclonal IgM lambda quantitated at 0.11 g/dl; free kappa/lambda ratio was 1.17 (normal 0.26-1.65). Renal ultrasound demonstrated slightly asymmetric kidneys. Renal artery magnetic resonance angiography was normal. Light microscopy of left kidney biopsy showed 6 end-stage sclerotic glomeruli and 14 viable glomeruli. Nodular mesangial expansion, thickened peripheral capillary basement membranes, tubular atrophy, interstitial fibrosis, arteriolar intimal sclerosis, and patchy lymphoplasmacytic infiltrates were observed (Fig. 1). Congo red stain was negative. Immunofluorescence was positive for focal granular mesangial IgM deposits. Electron microscopy showed thickened glomerular basement membranes and expanded mesangial matrix, frequently forming mesangial matrix nodules. There were no electron dense deposits, and foot processes were fused in a patchy pattern. These findings were suggestive of diffuse and nodular glomerulosclerosis with moderate to severe arteriosclerosis.In the absence of other etiologies, it is possible that hypertension was responsible for nodular glomerulosclerosis in this patient. It is speculated that individuals with long standing hypertension have an increased or reset sensitivity to non-diabetic glycemic levels resulting in an exaggerated glomerulovascular response [1].

Diabetic Nephropathy without Diabetes

“…In order to have homogeneity as to the diagnostic criteria and recorded data, records published before 1999 were excluded ( n = 14). Twenty-two records were included [ 3 , 4 , 5 , 6 , 8 , 9 , 10 , 11 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ], from 25 screened records. Three were excluded because they did not meet criteria for precise diagnosis.…”