Serum-Soluble ST2 (sST2) and NT-proBNP Levels in Children With Pulmonary Arterial Hypertension

Soluble ST2 (sST2) is a member of the interleukin-1 receptor family and is considered a novel biomarker of inflammation, fibrosis, and cardiac stress. Additionally, sST2 is accepted by guidelines as a measure of risk stratification in patients with heart failure.
 
Our study enrolled 53 subjects: 23 patients who were followed up for pulmonary arterial hypertension (PAH) and were prescribed different medications and 30 healthy children admitted to the pediatric cardiology outpatient clinic with chest pain or innocent murmurs as the control group. The plasma concentration of NT-proBNP was analyzed via the electrochemiluminescence method, and the sST2 level was analyzed via the ELISA method.
 
The mean age was 13.9 years (5.5–18 y) in the case group and 9.6 years (3–17 y) in the control group. The mean NT-proBNP level was significantly higher in the patient group than in the control group (763.73±2432.67 pg/mL vs 51.71± 30.08 pg/mL; P<0.01). The mean sST2 level was 1469.26±510.9 pg/mL in the patient group and 1151.30±655.99 pg/mL in the control group (P>0.05).
 
Our results suggest that sST2 could be a significant indicator of right heart failure and cardiovascular mortality in children, as well as a novel biomarker of PAH. However, we found that the serum sST2 level was not as useful as the serum NT-proBNP level in this regard. Further studies with larger patient series are needed to evaluate sST2 as a biomarker in patients with PAH. (Iranian Heart Journal 2022; 23(4): 46-51)