S155 The role of ST2 in a model of pulmonary hypertension

Soluble ST2 as a Potential Biomarker for Risk Assessment of Pulmonary Hypertension in Patients Undergoing TAVR?

Background: Severe aortic valve stenosis (AS) is associated with pulmonary hypertension (PH) and has been shown to limit patient survival. Soluble suppression of tumorigenicity-2 (sST2) is a cardiovascular biomarker that has proven to be an important prognostic marker for survival in patients undergoing transcatheter aortic valve replacement (TAVR). The aim of this study was to assess the importance of the sST2 biomarker for risk stratification in patients with severe AS in presence or absence of PH. Methods: In 260 patients with severe AS undergoing TAVR procedure, sST2 serum level concentrations were analyzed. Right heart catheter measurements were performed in 152 patients, with no PH detection in 43 patients and with PH detection in 109 patients. Correlation analyses according to Spearman, AUROC analyses and Kaplan–Meier curves were calculated. Results: Patients with severe AS and PH showed significantly higher serum sST2 concentrations (p = 0.006). The sST2 cut-off value for non-PH patients regarding 1-year survival yielded 5521.15 pg/mL, whereas the cut-off value of PH patients was at a considerably higher level of 10,268.78 pg/mL. A cut-off value of 6990.12 pg/mL was related with a significant probability of PH presence. Survival curves showed that patients with severe AS and PH not only had higher 1-year mortality, but also that increased levels of sST2 plasma concentration were associated with earlier death. Conclusion: sST2 definitely has the potential to provide information about the presence of PH in patients with severe AS, in a noninvasive way.

IL-33 acts as a foe to MIA PaCa-2 pancreatic cancer

IL-33 is a member of the IL-1 family of cytokines, and no study has been performed to address its direct anti-tumor effect. This study is designed to investigate whether IL-33 has any direct effect on pancreatic cancer. Clonogenic survival assay, immunohistochemistry, TUNEL staining, proliferation, caspase-3 activity kits and RT-PCR were used to evaluate the effects of IL-33 on cell survival, proliferation and apoptosis of a pancreatic cancer cell line, MIA PaCa-2. We found that the percentage of colonies of MIA PaCa-2 cells, PCNA+ cells and the OD value of cancer cells were all decreased in the presence of IL-33. TUNEL+ cells and the relative caspase-3 activity in cancer cells were increased in the presence of IL-33. We further found that its anti-proliferative effect on cancer cells correlated with downregulation of pro-proliferative molecules cdk2 and cdk4 and upregulation of anti-proliferative molecules p15, p21 and p53. Its pro-apoptotic effect correlated with downregulation of anti-apoptotic molecule FLIP and upregulation of pro-apoptotic molecule TRAIL. These results suggest that IL-33 presents significant anti-tumor effects by inhibition of proliferation and induction of apoptosis of MIA PaCa-2 pancreatic cancer cells. Thus, strength of IL-33/ST2 signal pathway might be a promising way to treat pancreatic cancer.

Plasma soluble ST2 levels correlate with disease severity and predict clinical worsening in patients with pulmonary arterial hypertension

BACKGROUND

Soluble suppression of tumorigenicity (sST2) has been proposed to be a marker for biomechanical strain and a possible predictor of mortality in patients with chronic heart failure. The use of sST2 in pulmonary arterial hypertension (PAH) has not been well defined.

HYPOTHESIS

Plasma sST2 levels may correlate with the disease severity and predict clinical worsening in PAH.

METHODS

We performed a cohort study of 40 idiopathic PAH patients with data on demographics, exercise capacity, echocardiographic parameters, laboratory tests, hemodynamics, and medications. Plasma sST2 was assessed with the high-sensitivity ST2 ELISA kit at diagnostic catheterization. All patients were followed up from the date of blood sampling. The endpoint was clinical worsening.

RESULTS

sST2 was significantly elevated in patients with idiopathic PAH compared with control subjects (28.9 ± 13.9 vs 20.7 ± 7.5 ng/mL, P = 0.003). Pearson correlation analysis revealed that sST2 levels correlated with cardiac index (r = -0.534, P = 0.000) and pulmonary vascular resistance (r = 0.350, P = 0.027), and could reflect disease severity of PAH. After a mean follow-up of 14 ± 5 months, 12 patients showed clinical worsening. Receiver operating characteristic analysis suggested that sST2 levels >31.4 ng/mL discriminated clinical worsening with a sensitivity and specificity of 83.3% and 78.6%, respectively. Kaplan-Meier analysis showed that higher sST2 levels (>31.4 ng/mL) were associated with poor clinical outcomes (P = 0.008). Multivariate Cox regression analysis showed that sST2 was an independent predictor of clinical worsening (hazard ratio: 6.067, 95% confidence interval: 1.317-27.948, P = 0.021).

CONCLUSIONS

sST2 correlates with disease severity and is a significant predictor of clinical worsening in patients with PAH.