Abstract: TH-PO621

An Unusual Cause of Nephrotic Syndrome: LCAT Deficiency

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Makar, Melissa, Duke University Medical Center, Durham, North Carolina, United States
  • Kovalik, Eugene C., Duke University Medical Center, Durham, North Carolina, United States
Background

Lecithin-cholesterol acyltransferase (LCAT) deficiency is an autosomal recessive disorder in which cholesterol cannot be esterified on high-density lipoprotein (HDL). The subsequent accumulation of unesterified cholesterol leads to kidney failure. Although it mainly affects those of European decent, we present two cases in African-Americans.

Methods

In Case 1, a 30 year old African-American female was evaluated for proteinuria and hematuria seen on routine urinalysis during a pre-operative evaluation. She had lower extremity edema; an estimated glomerular filtration rate (eGFR) of 115 ml/min/1.73m2; and 9 grams of proteinuria on 24 hour urine collection. Her serologies were negative; and on kidney biopsy, her light microscopy showed vacuolization of her capillary loop basement membranes while her electron microscopy showed subendothelial, intermembranous, and mesangial deposits of lamellated, myelin-figure lipid material along with mesangial and endocapillary foam cells. In support of LCAT deficiency, her HDL and serum cholesteryl levels were very low at 8 mg/dl and 13%, respectively. Unfortunately, as expected with LCAT deficiency, she progressed to end-stage kidney disease at age 36 despite blood pressure control with an angiotensin-converting enzyme inhibitor (ACEI). Two years later, she underwent a deceased donor kidney transplant and was doing well at last check. In Case 2, a 69 year old African-American female with a longstanding history of dyslipidemia was seen for a HDL of less than 5 mg/dl. A low serum cholesteryl ester level of 15% confirmed her diagnosis. At the time, her eGFR was 102 ml/min/1.73m2 and she had no proteinuria while on three anti-hypertensive agents including an ACEI. Over the past seven years, her eGFR has fallen to 52 ml/min/1.73m2 and she has developed proteinuria of 4 grams on spot check. A subsequent full evaluation was otherwise negative, and she is followed closely as an outpatient.

Conclusion

Although rare, LCAT deficiency should be included in the differential for nephrotic syndrome in all persons with a low HDL. The diagnosis can be made by low serum cholesteryl ester levels; kidney biopsy shows diffuse foam cells and lipid deposits. Current treatment is supportive care.