A 58-year-old male was referred to our center by his primary care physician due to nephrotic syndrome. He had massive proteinuria (7.38 g/day) and hypoalbuminemia (1.9 g/dl). He had been treated for diabetes since the age of 50 years and had been started on insulin therapy at the age of 55 years. He had been well-managed (HbA1c, 5.3%), although a pre-proliferative retinopathy and mild renal dysfunction (sCr, 1.38 mg/dl) became evident. His renal biopsy revealed 5 of 22 glomeruli with global sclerosis. The residual glomeruli showed massive foam cell infiltration in the glomerular capillaries and severely widened mesangium (fig. ). These foam cells stained positive for CD68 (not shown). Transmission electron microscope images also revealed foam cell infiltration mainly located in the capillaries containing scattered lipid droplets and lamellar bodies in their cytoplasm (fig. ). The glomerular tufts were enlarged with hyalinosis, mesangiolysis and microaneurysmal formation, which were consistent with diabetic glomerulosclerosis. The interstitium and tubules showed moderate fibrosis and atrophy (50% of the cortical region). The foamy change was seen in some tubular epithelial cells, but no interstitial foamy cells were found. The interlobular arteries showed a moderate degree of fibrous intimal thickening, and the arterioles also showed a moderate degree of subendothelial hyalinosis. Immunofluorescence studies revealed nonspecific linear IgG deposits along the GBM; however, no significant deposit was found by electron microscopy. The patient's lipid profile showed type III HLP (table ). He had an apoE2 homozygote phenotype and the Arg158Cys genotype with no other mutations. Three years after the diagnosis, he progressed to renal failure and was started on hemodialysis.
A 78-year-old male with nephrotic syndrome was referred to our center by his primary care physician. The patient had a history of hypertension since the age of 45 years, hypothyroidism since the age of 68 years and diabetes mellitus since the age of 70 years. He also had a history of percutaneous coronary intervention for coronary artery disease and femoropopliteal bypass surgery for peripheral arterial disease at the age of 74 years, and a history of Wallenberg syndrome since the age of 77 years. He was being treated with an angiotensin II receptor blocker, a calcium-channel blocker, pitavastatin, aspirin and levothyroxine sodium hydrate. Diabetic control by diet and an oral α-glucosidase inhibitor were sufficient. There was no evidence of retinopathy or albuminuria before the episode of nephrosis. His urinalysis on admission was positive for proteinuria (2.5 g/day) and red blood cells (1–4/hpf). His blood chemistry findings were as follows: albumin 3.2 g/dl, creatinine 1.11 mg/dl and HbA1c 6.1%. A kidney biopsy revealed 21 glomeruli, of which 2 were globally sclerotic. The glomeruli showed increased mesangial matrices and mild GBM thickening. Massive foam cells had infiltrated into the glomerular capillaries and mesangial region (fig. ). These foam cells stained positive with Oil Red O (fig. ) and immunohistochemically stained positive for CD68 (fig. ). Transmission electron microscope images also revealed foam cell infiltration mainly located in the capillaries, and some mesangial cells showed scattered lipid droplets in their cytoplasm (fig. ). Mild interstitial fibrosis and tubular atrophy (20% of the cortical region) as well as moderate arteriosclerosis and arteriolar hyalinosis were found. The foamy change was seen in some tubular epithelial cells but no interstitial foamy cells were found. Immunofluorescence studies revealed segmental deposits of IgM and C3 in the mesangial area and slightly peripheral IgG deposits in the glomeruli; however, no significant deposit was found by electron microscopy. He had an apoE2 homozygote phenotype and the Arg158Cys genotype with no other mutations. After the diagnosis, ezetimibe was added to his statin therapy. The patient's most recent serum creatinine was increased to 2.1 mg/dl after 2 years.