The relationship between the serum phosphatase and tensin homolog (PTEN) and TLR4 and the severity and prognosis of neonatal sepsis

Background: Neonatal sepsis is associated with severe systemic inflammation and high mortality. This study evaluated whether serum levels of phosphatase and tensin homolog (PTEN) and toll-like receptor 4 (TLR4) are associated with disease severity and prognosis in neonatal sepsis. Methods: This study included 116 neonates with sepsis and 50 healthy controls. Based on SOFA scores, septic neonates were classified into mild sepsis and severe sepsis groups; severe cases were further divided into 8 deaths and 44 survivors. Serum PTEN, TLR4, procalcitonin (PCT), C-reactive protein (CRP), heparin-binding protein (HBP), and white blood cell count (WBC) were measured. Correlations and diagnostic/prognostic performance were assessed using Pearson correlation and ROC analysis. Results: Inflammatory markers increased with disease severity. PCT rose from 0.12±0.01 ng/mL in controls to 0.75±0.14 in mild sepsis and 1.74±0.23 in severe sepsis; CRP increased from 5.34±0.36 to 28.84±3.52 and 77.26±6.49 mg/mL, respectively. PTEN declined from 3.05±0.17 ng/mL in controls to 2.25±0.15 in mild sepsis and 1.37±0.11 in severe sepsis, whereas TLR4 increased from 0.74±0.16 mg/mL to 1.35±0.14 and 2.51±0.20. Among severe cases, non-survivors had higher PCT (4.39±1.13 vs 1.63±0.36 ng/mL) and CRP (123.58±9.03 vs 68.34±5.27 mg/mL) than survivors. Non-survivors also had lower PTEN (0.95±0.16 vs 1.24±0.18 ng/mL) and higher TLR4 (2.86±0.20 vs 2.14±0.18 ng/mL). ROC analysis showed strong predictive value for PTEN (AUC 0.846; sensitivity 89.23%; specificity 86.23%) and TLR4 (AUC 0.857; sensitivity 90.31%; specificity 86.16%). Conclusion: Reduced PTEN and elevated TLR4 are associated with stronger inflammatory responses, greater sepsis severity, and poorer prognosis in neonates. These biomarkers may support early risk stratification and prognostic assessment.