Rare diagnosis in a patient with diabetes with nephrotic proteinuria

Abstract

We report a 63-year-old man with well-controlled type 2 diabetes mellitus and hypertension, who presented with new onset nephrotic proteinuria and rapid deterioration in renal function. The atypical clinical presentation prompted us to consider a non-diabetic and non-hypertensive cause and to perform a renal biopsy. A diagnosis of fibrillarglomerulonephritis (FGn) was made based on electronic microscopy. Proteinuria remained in nephrotic range despite treatment with prednisolone, and renal function deteriorated. We suggest that other causes of proteinuria should be considered in patients with diabetes who present with the nephrotic syndrome when there is no other evidence of microvascular disease. We review the spectrum of fibrillar glomerulopathies including FGn, primary and secondary amyloidosis and immunotactoid glomerulonephritis.

Keywords: proteinurea; renal intervention.

Figure 1

Hypertrophic glomeruli with diffuse mesangial expansion by an amorphous material negative for silver stain; no cell proliferation; normal capillary walls; tubular atrophy and interstitial fibrosis are present. Jones silver staining (x100).

Figure 2

Electron microscopy showing randomly arranged fibrils deposited in mesangial areas and along glomerular basal membrane (x20 000).