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

Abstract

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.

LRG1 Contributes to the Pathogenesis of Multiple Kidney Diseases: A Comprehensive Review

“…As aforementioned, LRG1 has been found to serve as an effective biomarker of kidney injury. In line with above findings, Popova et al [45] also reported LRG1 was up in serum and urine of patients with kidney injury induced by kidney transplant (n = 35). A positive correlation was found between serum and urine LRG1 (r = 0.41; 95% CI: 0.09 to 0.66; p = 0.01).…”

The disruptive role of LRG1 on the vasculature and perivascular microenvironment

“…In addition to plasma, increased urine LRG1 levels in diabetes is also associated with an increased risk of progression to end stage kidney disease independent of traditional cardiorenal risk factors ( 55 ), and in kidney transplant recipients LRG1 has been considered a potential kidney injury marker that correlates with other tubular injury markers and functional deterioration ( 141 ). These human data support the evidence from experimental studies that LRG1 is an important factor in driving CKD through initial effects on the kidney vasculature and the subsequent fibrotic response.…”