Leucine-Rich Alpha-2-Glycoprotein (LRG-1) as a Potential Kidney Injury Marker in Kidney Transplant Recipients

BACKGROUND: Kidney transplantation is the treatment of choice for most patients with end-stage renal disease. To improve patient and transplant survival, non-invasive diagnostic methods for different pathologies are important. Leucine-rich alpha-2-glycoprotein (LRG-1) is an innovative biomarker that is elevated in cases of angiogenesis, inflammation, and kidney injury. However, there are limited data about the diagnostic role of LRG-1 in kidney transplant recipients. The aim of this study was to evaluate the association between serum LRG-1, urine LRG-1, and kidney transplant function and injury. MATERIAL/METHODS: We enrolled 35 kidney transplant recipients in the study. LRG-1 in the serum and urine was detected using ELISA. We evaluated the correlation of serum and urine LRG-1 with traditional serum and urine kidney injury markers. RESULTS: A higher level of serum LRG-1 correlates with a higher level of urine LRG-1. Serum LRG-1 has a positive correlation with transplant age, serum urea, serum creatinine, serum cystatin C, proteinuria, and fractional excretion of sodium (FENa) and a negative correlation with hemoglobin and estimated glomerular filtration rate (eGFR). Urine LRG-1 has a positive correlation with serum cystatin C, proteinuria, and urine neutrophil gelatinase-associated lipocalin (NGAL). CONCLUSIONS: Higher levels of serum and urine LRG-1 are associated with kidney transplant injury and functional deterioration. Thus, LRG-1 might be also as a biomarker for tubular dysfunction in patients after kidney transplantation.