[Plasma NGAL and ADPKD progression].

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disease with variable rate of progression. It is associated with inter- and intra-familial variability. Neutrophil gelatinase-associated lipocalin (NGAL) has been implicated in pathological conditions and it is proposed as a biomarker for CKD progression. Our aim was to evaluate whether NGAL could be a good marker for progression of ADPKD, as we hypothesized. ADPKD patients with confirmed mutations (PKD1 n=33; PKD2 n=17) were enrolled and followed in a prospective study. Creatinine (sCr) and NGAL values were measured at baseline and on follow-up. Plasma NGAL was measured by Triage point of care test. CKD progression was defined as 15% decrease in eGFR from baseline to follow-up. Patients were divided into 2 groups based on median baseline NGAL and compared by the Kaplan-Meier curve. We enrolled 50 ADPKD pts (60%M age 41 yrs); mean sCr 1.30.7 mg/dl and median eGFR was 62 mL/min/1.73 m2. NGAL values are inversely correlated with baseline eGFR (r=-0.64, p<0.001). There was weak correlation between baseline NGAL and subsequent change in eGFR (r=0.28, p=0.05). 9/50 of patients had NGAL below limits of detection (60 pg/ml); median NGAL level was 79 pg/ml. At follow-up, 12 patients (24%) had progression as defined. No statistically significant relationship between higher NGAL and ADPKD progression was observed. We did not observe a relationship between NGAL and CKD progression in ADPKD patients; however 18% of patients had undetectable plasma NGAL levels. This raises doubt about the utility of the current NGAL assay as a biomarker for CKD progression in this population.