IDIOPATHIC NODULAR GLOMERULOSCLEROSIS - A CASE REPORT AND REVIEW OF LITERATURE

Idiopathic Nodular Glomerulosclerosis is a rare disease, it has characteristic similar appearance on microscopic level to diabetic nephropathy. It is diagnosed after excluding diabetes. There is some association with cigarette smoking (1), hypertension (2) and obesity although it has been reported in a normotensive, non-obese, non-diabetic woman as well (3).

We report a rare case of 52 year old male with remote history of hypertension who presented to the hospital with history of weakness, progressive dyspnea and difficulty walking. Patient had not seen a physician in a long time and was not taking any medications. There was no history of active smoking or drug abuse. He recently saw a physician and was started on atenolol for uncontrolled hypertension and initial labs were ordered. Patient was advised to come to the hospital emergency room after he was noted to have several abnormal labs. In the emergency room he had blood pressure of 84/42 and received crystalloid bolus. Laboratory date in the emergency room showed acute kidney injury with blood urea nitrogen of 176 mg/dl, serum Creatinine of 18.8 mg/dl, Glomerular filteration rate of 3 ml/min , Bicarbonate of less than 9 mmol/l and potassium of 5.9 mmol/l. Urine analysis revealed evidence of 3+ protein and 2+ blood. Urine protein and creatinine ratio showed 3.8 gm/mg of creatinine.  He received initial treatment for hyperkalemia and urgent surgical consultation was requested for dialysis catheter placement. Patient received urgent dialysis treatment. Secondary workup for nephrotic syndrome did not reveal any abnormal studies. Patient did well with dialysis treatments. His blood glucose levels were within acceptable range and Hemoglobin A1c was 4.9%. A kidney biopsy was ordered. 

Kidney biopsy showed 20 glomeruli 10 of which were globally sclerosed. The remaining glomeruli showed nodular sclerosis with thickened basement membranes and marked arteriolar hyalinosis without any evidence of immune mediated glomerulonephritis. There was 70-80% interstitial fibrosis and tubular atrophy.

Idiopathic Nodular Glomerulosclerosis is a rare disease. Patients in whom the disease has been identified are older with long standing history of hypertension and smoking. Our patient is younger with unknown duration of hypertension but did not have diabetes, obesity, history of smoking or hyperlipidemia. His only risk factor was hypertension which was untreated. Smoking, advanced age and hypertension may be independent risk factors for Idiopathic Nodular Glomerulosclerosis and need to be studied more. Other causative agents need to be identified in these patients with Idiopathic Nodular glomerulosclerosis to recognize these patients earlier in the course of this disease.

References:

1.     Nasr SH, D’Agati VD. Nodular glomerulosclerosis in the non-diabetic smoker. J Am Soc Nephrol 2007; 18: 2032-2036

2.     Li W, Verani RR. Idiopathic nodular glomerulosclerosis: a clinicopathologic study of 15 cases. Hum Pathol 2008; 39:1771–1776

3.     Uchida T, Oda T et al. Idiopathic nodular glomerulosclerosis in a never-smoking, normotensive, non-obese, normal-glucose-tolerant middle-aged woman. Clin Kidney J (2012) 5; 445-448