An asymptomatic 23-y/o man is referred to you for evaluation of hypertension and proteinuria detected during a periodic health evaluation. Medical history is remarkable for enuresis before age 10. Since then, he has been in good health. The patient is muscular and appears healthy. Blood pressure is 140/86 mm Hg. He has no edema or evidence of hypertensive retinopathy. The remainder of the physical examination, including cardiac examination, is normal. Electrocardiogram shows no signs of left ventricular hypertrophy.
Serum creatinine: 1.2 mg/dL
Serum electrolytes: Normal
Serum albumin: 4.3 g/dL
Urinalysis: Specific gravity 1.015; 3+ albumin, no blood Urine protein: 1.9 g/24 hr
Creatinine clearance: 140 mL/min
On ultrasound examination, the left kidney is 11.3 cm and the right is 11.0 cm; cortical thickness in the upper poles is reduced. Percutaneous biopsy of the right lower pole yields 24 glomeruli, two show global sclerosis, and ten show focal and segmental glomerulosclerosis. The remaining glomeruli are enlarged. Patchy interstitial fibrosis and tubular atrophy is seen in the vicinity of the sclerotic glomeruli. Electron microscopy of a nonsclerotic glomerulus shows mostly well-preserved morphology with occasional podocyte foot process effacement.
In addition to treatment with an ACE inhibitor or angiotensin-receptor blocker to reduce blood pressure below 130/80 mm Hg, which of the following should you do now?
A. Begin treatment with low-dose cyclosporine
B. Begin an eight-week course of prednisone
C. Begin long-term prophylaxis with trimethoprim–sulfamethoxazole
D. Refer for evaluation and treatment of vesicoureteric reflux
E. No further studies or therapy is indicated
No further therapy indicated. This is FSGS, most likely primary or perhaps familial. The prognosis correlates with degree of proteinuria. All patients should be treated to normal blood pressure and with ACE-inhibitors or ARBs to minimize proteinuria. Hyperlipidemia should be controlled and salt restriction with diuretics used to control edema. The use of corticosteroids remains controversial with little evidence for benefit, although longer courses (16 weeks to 6 months) may provide some benefit. One randomized controlled study of steroid-resistant patients found that patients treated with cyclosporine and prednisone had better outcomes than patients treated with prednisone alone (Cattran, et al. KI. 1999;56:2220).
(Source: Dr. Brad Denker, BIDMC/Harvard Medical School, Boston)