Phoenixin-14 Downregulation as a Novel Prognostic Biomarker in Sepsis: Molecular and Clinical Evidence

Background:

Sepsis is a leading cause of morbidity and mortality in intensive care units (ICUs) worldwide, accounting for millions of deaths annually. Despite the use of established biomarkers such as procalcitonin, C-reactive protein (CRP), and interleukin-6 (IL-6), their predictive accuracy for mortality remains suboptimal. Phoenixin-14 (PNX-14), a neuropeptide with demonstrated anti-inflammatory and antioxidant effects in preclinical studies, has not been extensively investigated in the context of sepsis. This study aimed to evaluate the prognostic value of serum PNX-14 levels and gene expression in predicting hospital mortality among ICU patients with sepsis.

Methods:

This prospective observational cohort study included 77 adult patients admitted to a tertiary ICU with a diagnosis of septic shock between March and November 2024. Patients under 18 years, pregnant women, and those with chronic steroid use, immunosuppression, malignancy, severe liver disease, or early discharge/death within 72 hours of diagnosis were excluded. Upon ICU admission, demographic and clinical data were recorded, including Acute Physiology and Chronic Health Evaluation II (APACHE II) and Sequential Organ Failure Assessment (SOFA) scores. Serum PNX-14, CRP, procalcitonin, IL-1β, IL-6, tumor necrosis factor-α (TNF-α), and IL-10 levels were measured using ELISA. Gene expression levels of PNX-14 were quantified via real-time PCR. The primary endpoint was hospital mortality; secondary endpoints included associations and correlations between PNX-14 levels, inflammatory markers, and severity scores.