Ang-2, Tie-2, and Ang-2/Tie-2 ratio serum levels as diagnostic and prognostic biomarkers of sepsis in critically ill patients

Sepsis represents one the main cause of death in patients admitted to the intensive care. Biomarkers offer an alternative approach to the diagnostic and prognostic evaluation and improve the outcomes. Angiopoietin 2 (Ang-2) and Tyrosine kinase 2 (Tie-2) are biomarkers which may be involved in sepsis, Ang-2 being responsible for vascular remodelling while Tie-2 is their endothelial receptor.

The aim of the study: To assess the Ang-2, Tie-2 and Ang-2/Tie-2 ratio serum levels in septic and non-septic patients and to investigate the independent value of circulating Ang-2, Tie-2, and Ang-2/Tie-2 ratios as predictors of prognosis in critically ill medical patients.

Study design: The study included 74 adults admitted to an intensive care unit (ICU). The patients were separated in two groups: Group A [sepsis: n=40] and Group B [no-sepsis: n= 34] patients. Serum levels of Ang-2 and Tie-2 were determined in the first 12 hours after admission and were correlated with ICU severity scores, APACHE II, SOFA and SAPS and with the death rate.

Results: Group A gave significantly higher values (p=0.01), for serum Ang-2 (11.07±9.21 ng/ml) compared to Group B (6.18±5.28 ng/ml). The level of Tie-2 was also higher (11.03±5.12 ng/ml) in Group A compared to Group B (9.46±4.99 ng/ml) (p=0.19). In Group A, the Ang-2/Tie2 ratio showed higher values than Group B (p=0.02). There was a positive association between severity scores (APACHE II, SAPS, and SOFA) and Ang-2, and Ang-2/ Tie-2 ratio, but not for Tie2.

Conclusions: In our study Ang-2 and Ang-2/Tie-2 ratio serum levels had independent diagnostic value in patients with sepsis, as measured on admission.