Abstract
OBJECTIVES:
Neutrophil gelatinase-associated lipocalin (NGAL) has been proved as a sensitive biomarker in acute and chronic renal injury. Renal impairment is a common complication of multiple myeloma (MM). We attempt to assess the value of NGAL for the early and accurate diagnosis of renal injury in MM patients.
METHODOLOGY:
Forty-five MM patients with CKD stage I to V(MM-renal group), 20 MM patients with normal kidney function (MM-non-renal group), and 37 healthy volunteers (healthy control) were compared for serum and urinary NGAL and other renal injury biomarkers (Creatinine[CRE]; Cystatin-C [CysC]; N-acetyl-beta-D-glucosaminidase [NAG]). Other biomarkers reflect the inflammation and tumor burden like high-sensitivity C-reactive protein(hs-CRP) and urine free light chain were also detected.
RESULTS:
Among the biomarkers of renal injury, the assessment of serum CysC, CRE and NGAL was a reliable tool to distinguish MM-renal from MM-non-renal. Both serum and urinary NGAL levels were higher in MM-renal patients than in MM-non-renal or healthy controls (187.10 (45.60-699.60) vs 136.70(47.70-216.50) vs 117.7 (69.3-192.3), P< 0.01; 37.50 (6.30-412.10) vs 18.00(0.50-66.50) vs 11.2 (0.9-69.1), P< 0.01). Univariate analysis showed that both serum (Odds Ratio = 1.009; 95%CI 1.002-1.017; P= 0.018) and urinary NGAL (Odds Ratio = 1.038; 95%CI 1.003-1.073; P= 0.031) as well as serum CysC (Odds Ratio = 9.875; 95%CI 1.685-57.882; P= 0.011) were strong predictors for the risk of renal injury in MM patients. Moreover, the urinary NGAL level was negatively correlated with estimated glomerular filtration rate (eGFR) (r= -0.586, P= 0.00003) and has a tendency towards positive correlation with urine free light chain (r = 0.235, P = 0.124) and hs-CRP (r = 0.379, P = 0.074).
CONCLUSIONS:
The present study demonstrated that urinary NGAL was not superior to serum NGAL in distinguishing MM-renal group from MM-non-renal group. And it could be considered an independent predictor of renal injury from multiple myeloma reflecting active kidney damage, tumor burden, and inflammation.