ASA: Studies Examine Urinary Biomarkers of Kidney Disease
NGAL shown to best identify kidney injury in surgery patients with normal baseline function
WEDNESDAY, Oct. 21 (HealthDay News) -- The biomarker neutrophil gelatinase-associated lipocalin (NGAL) may best identify acute kidney injury in cardiac surgery patients with normal preoperative kidney function, and undetected kidney cancer may influence urine concentrations of another biomarker, kidney injury molecule-1 (KIM-1), according to research presented at the annual meeting of the American Society of Anesthesiologists, held from Oct. 17 to 21 in New Orleans.
David R. McIlroy, of Columbia University in New York City, and colleagues analyzed data from 426 adult cardiac surgery patients. Urine was collected at several points before and after surgery, and preoperative estimated glomerular filtration rate (eGFR) was calculated. The association between postoperative urinary NGAL and acute kidney injury varied by eGFR, with the best performance found in people with normal function before the surgery. However, patients with the highest preoperative eGFR who developed acute kidney injury had paradoxically lower postoperative NGAL.
Jerry Morrissey, Ph.D., of the Washington University School of Medicine in St. Louis, and colleagues analyzed data from urine samples of 29 patients undergoing nephrectomy for kidney cancer as well as 19 controls. Urinary KIM-1 concentration was found to increase along with tumor stage. No relationship was seen for NGAL concentrations and tumor stage, or between patients and controls in terms of NGAL.
"Since the majority of the kidney tumors of this cohort were discovered incidentally, especially those in stage 1, our study supports the conclusion that occult kidney cancer can influence urine KIM-1 concentrations and confound the use of this biomarker to accurately diagnose and/or predict perioperative acute kidney injury. Urinary NGAL measurements would not be similarly affected," Morrissey and colleagues conclude.