Serum Galectin-3, Galectin-9 and IL-6 levels in acute herpes zoster: a prospective cohort study on the risk and severity of postherpetic neuralgia

Postherpetic neuralgia (PHN) is a debilitating complication of herpes zoster (HZ), yet reliable biomarkers for early prediction remain elusive. This study aimed to evaluate the predictive value of serum Galectin-3, Galectin-9, and IL-6 levels for PHN development. In this prospective cohort study, a total of 76 participants were enrolled in this prospective cohort study, including 56 patients with acute herpes zoster (HZ) and 20 healthy controls. Based on 3-month follow-up outcomes, the HZ patients were further divided into two groups: those who developed postherpetic neuralgia (PHN group, n = 18) and those who did not (non-PHN group, n = 38). The patients were followed up to evaluate the development of PHN. Serum levels of Galectin-3, Galectin-9, and IL-6 were quantified via ELISA. Receiver operating characteristic (ROC) curves and multivariate Cox regression analyses were employed to assess biomarker performance and independent predictors of PHN. Baseline serum levels of all three biomarkers were significantly elevated in patients who subsequently developed PHN compared with both non-PHN patients and healthy controls (all P < 0.01) and were strongly correlated with pain severity (NRS scores; ρ = 0.68–0.75, P < 0.001). ROC analysis identified Galectin-9 as the strongest predictor of PHN (AUC = 0.85, sensitivity = 94.4%, specificity = 71.05%), outperforming Galectin-3 (AUC = 0.82) and IL-6 (AUC = 0.76). Multivariate Cox regression confirmed elevated Galectin-9 (HR = 3.21, 95% CI: 1.85–5.58, P < 0.001), older age (HR = 1.04/year, P = 0.012), and larger lesion area (HR = 1.92, P = 0.003) as independent risk factors for PHN. Galectin-9 shows promise as a potential biomarker for identifying patients at elevated risk for PHN, warranting further validation in larger, multi-center cohorts to establish its clinical utility.