Evaluation of the causes affecting the development of pruritus in patients with peritoneal dialysis

Nomogram to Estimate the Risk of Chronic Kidney Disease-Associated Pruritus in Patients with End-Stage Renal Disease Undergoing Peritoneal Dialysis: Model Development and Validation Study

INTRODUCTION

Chronic kidney disease-associated pruritus (CKD-aP) frequently occurs in patients with end-stage renal disease (ESRD) undergoing peritoneal dialysis (PD) and presents a therapeutic challenge to physicians owing to the diversity of its pathogenesis. Herein, we developed and validated a nomogram model for individualized risk estimation of CKD-aP and investigated the possible causes of CKD-aP in PD patients.

METHODS

We retrospectively screened patients with CKD-aP who underwent PD between 2021 and 2023 at the First Affiliated Hospital of Xi'an Jiaotong University Peritoneal Dialysis Center. Nomograms for each outcome were computed from multivariate logistic regression models with the least absolute shrinkage and selection operator regression and univariate logistic regression for variable selection. The discriminative ability was estimated by Harrell's C-index, and the accuracy was assessed graphically with a calibration curve plot. Models were validated internally using bootstrapping and externally by calculating their performance on a validation cohort. Decision curve analysis was used to assess the model's clinical usefulness.

RESULTS

In all, a total of 487 patients were entered in the analysis, including 325 in the development cohort and 162 in the validation cohort. The final nomogram incorporated five variables: age, interleukin-6, hemoglobin, residual urine volume, and renal Kt/V. The C-index of the model was 0.733 (95% CI: 0.679-0.787), and the calibration curve was a straight line with a slope close to 1. Both internal and external validations confirmed the model's good performance, with C-index of 0.725 (95% CI: 0.662-0.774) and 0.706 (95% CI: 0.623-0.789), respectively. Decision curve analysis showed that the nomogram had good clinical benefits.

CONCLUSION

Our study proposes a nomogram model for CKD-aP risk assessment in ESRD patients with PD. This nomogram might help in clinical decision-making and evidence-based selection of therapy.

Serum thymus and activation-regulated chemokine level is associated with the severity of chronic kidney disease-associated pruritus in patients undergoing peritoneal dialysis

BACKGROUND

Thymus and activation-regulated chemokine (TARC), which induces a Th2-dominated inflammation, is a well-known biomarker that reflects the severity of atopic dermatitis. The present study aimed to evaluate TARC as a Th2-associated marker with chronic kidney disease-associated pruritus (CKD-aP) in patients with peritoneal dialysis (PD).

METHODS

This single-centre cross-sectional study included patients who underwent PD in our hospital between August 2020 and July 2021. The severity and impaired quality of life (QOL) of CKD-aP were assessed using the visual analogue scale (VAS) and Japanese version of the 5-D itch scale (5D-J), respectively.

RESULTS

A total of 48 patients with PD were included in the present study. Age and dialysis vintage were (mean ± SD) 64.8 ± 12.0 year and (median (IQR)) 38.5 (11.5-91.5) month, respectively. VAS and 5D-J scores were 3.3 ± 2.0 and 10.5 (9.0-12.0), respectively. Serum TARC level was 481.5 (278.9-603.4) pg/mL (upper limits of normal 450 pg/mL) and significantly correlated with VAS (r = 0.39, p = 0.006) and 5D-J score (r = 0.37, p = 0.009). Multivariate linear analysis revealed that higher serum TARC level was significantly associated with VAS (p < 0.001) and 5D-J score (p < 0.001). Furthermore, the serum brain natriuretic peptide level tended to be associated with VAS (p = 0.060) and 5D-J score (p = 0.029).

CONCLUSION

Serum TARC level is an independent predictor of the severity and impaired QOL of CKD-aP in patients with PD, and TARC might be involved in the pathogenesis of CKD-aP.