The utility of thymus and spleen ultrasound in the early prediction of neonatal sepsis

Abstract

Background

This investigation aimed to determine the utility of postnatal, ultrasonographically-derived dimensions of the thymus and spleen as imaging indicators for the prediction of early-onset neonatal sepsis (EOS).

Material and Method

In this case-control study, 30 term neonates diagnosed with Early-Onset Sepsis (EOS), based on European Medicines Agency (EMA) criteria, were compared to 30 healthy, matched control neonates. All participants underwent ultrasonography to quantify thymic and splenic dimensions. Receiver Operating Characteristic (ROC) curve analysis was employed to determine the optimal diagnostic cut-off value for thymic volume. Statistical significance was set at p < 0.05.

Results

Baseline demographics were comparable between patient and control groups (p > 0.05). A profound and statistically significant reduction in thymic volume (p < 0.001) was identified in the patient group compared to healthy controls, demonstrating a significant correlation with EOS, whereas spleen dimensions did not show a similar association. ROC analysis confirmed the high diagnostic accuracy of thymic volume (Area under the Curve [AUC]: 0.896; 95% CI: 0.813–0.978; p < 0.001). An optimal diagnostic threshold of ≤9 mL was established, yielding a sensitivity of 90.0% and a specificity of 83.3%. The corresponding Diagnostic Odds Ratio was 45.0, signifying a 45-fold increased odds of sepsis in neonates with a thymic volume below this value.

Conclusion

Thymic volume is significantly reduced in neonates with Early-Onset Sepsis (EOS), making it a powerful, non-invasive diagnostic indicator. Serial ultrasonographic assessment of thymic volume holds promise for improving the diagnostic and prognostic management of neonatal sepsis. Spleen dimensions, however, showed limited utility as an early predictive indicator.