Abstract
BACKGROUND: Adult nephrotic syndrome is a well-known kidney disease that causes heavy proteinuria, hypoalbuminemia, hypercholesterolemia, edema, and hypertension. The treatment varies according to its underlying cause but often faces medication resistance or adverse drug effects. CASE PRESENTATION: A Japanese woman in her 80s presented with nephrotic syndrome after a 3 year latent period of urinary protein and occult blood. She did not have any secondary causes of nephrotic syndrome. Renal biopsy revealed thin glomerular basement membrane, partial foot process fusion on electron microscopy with minor glomerular change on light microscopy, and slight coarse immunoglobulin M deposition in the mesangium on immunofluorescence microscopy, which was inconsistent with any other glomerular diseases. Without steroid treatment, she dramatically remitted from proteinuria after the administration of the renal protective agents enalapril, ezetimibe, rosuvastatin, and dapagliflozin. Recurrence after 8 months of follow-up subsided with the administration of additional doses of the agents. CONCLUSIONS: This case illustrated the novel outcomes of combining medical treatment without steroid use for nephrotic syndrome with thin glomerular basement membrane disease. At the time of writing this report, the patient's renal function was stable and she was free of edema, although moderate proteinuria and occult hematuria persisted. The final diagnosis was uncertain because of the lack of genetic investigation; however, the response to the aforementioned medical treatment suggests the effectiveness of the supportive therapy.