Validity of Plasma Neuropeptide Y in Combination with Clinical Factors in Predicting Neuralgia Following Herpes Zoster.

Background: Numerous lines of evidence suggest that neuropeptide Y (NPY) is critically involved in the modulation of neuropathic pain. Postherpetic neuralgia (PHN) is characterized by prolonged duration, severe pain, and significant treatment resistance, substantially impairing patients' quality of life. This study aims to evaluate the potential of plasma NPY levels in patients with PHN as a predictive biomarker for the development of this condition. Methods: Between February 2022 and December 2023, 182 patients with herpes zoster (HZ) were recruited. Thirty-eight volunteers with no history of HZ were also recruited as controls. Clinical factors, NPY, brain-derived neurotrophic factor (BDNF), and nerve growth factor (NGF) were assessed within 3 days of healing. Logistic regression analysis was used to predict the development of PHN. Results: NPY levels were lower and BDNF and NGF were higher in HZ patients than those in controls. Only NPY levels were lower in patients with PHN (n = 59) compared with those without PHN (n = 123). Age, acute pain severity, and rash area were independent predictors of PHN, as were NPY levels. The area under the curve (AUC) to predict the development of PHN based on the combination of NPY levels and clinical factors was 0.873 (95% CI: 0.805 to 0.940), and the AUC was 0.804 based on only clinical factors (AUC: 0.804, 95% CI: 0.728 to 0.881). Conclusion: Low plasma NPY levels are a predictor of developing PHN in patients with HZ. Combining clinical predictors with NPY levels may improve predictive accuracy.