Predictive Value of Collagen Biomarkers in Advanced Chronic Kidney Disease Patients

Patients with chronic kidney disease have an increased risk of all-cause death. The value of collagen biomarkers such as procollagen type I carboxy-terminal propeptide (PICP) and procollagen type III N-terminal peptide (P3NP), in end-stage renal disease (ESRD), has not yet been defined (in the literature and in clinics). The purpose of this study was to determine the potential value of these new biomarkers in the prediction of mortality in this population. Plasma PICP and P3NP levels were determined in 140 patients with ESRD, not yet on dialysis, who were followed up for 36 +/- 5.3 months. During follow-up, 58 deaths were recorded (41.4%), with the majority of them being cardiovascular deaths (43, 74.13%). Using the ROC curve, the cut-off value for the prediction of mortality for PICP was 297.31 mu g/L, while for P3NP, the cut-off value was 126.67 mu g/L. In univariate analysis, a value of PICP above the cut-off point was associated with a fivefold increased risk of mortality (hazard ratio (HR) 5.071, 95% confidence interval 1.935-13.29, p = 0.001) and a value of P3NP above the cut-off point was associated with a twofold increased risk of mortality (HR 2.089, 95% CI 1.044-4.178, p = 0.002). In a multivariable Cox proportional hazards model, PICP values remained independent predictors of mortality (HR 1.22, 95% CI 1.1-1.31, p < 0.0001). Our data suggest that the collagen biomarker PICP is an independent predictor of mortality in ESRD patients who are not yet on dialysis.