Objectives: Pulmonary hypertension is one of the leading causes of death in systemic sclerosis. Early detection and treatment of pulmonary hypertension in systemic sclerosis is crucial. Nailfold capillaroscopy microscopy, vascular autoantibodies AT1R and ETAR, and several candidate-biomarkers have the potential to serve as noninvasive tools to identify systemic sclerosis patients at risk for developing pulmonary hypertension. Here, we explore the classifying potential of nailfold capillaroscopy microscopy characteristics and serum levels of selected candidate-biomarkers in a sample of systemic sclerosis patients with and without different forms of pulmonary hypertension.Methods: A total of 81 consecutive systemic sclerosis patients were included, 40 with systemic sclerosis pulmonary hypertension and 41 with no pulmonary hypertension. In each group, quantitative and qualitative nailfold capillaroscopy microscopy characteristics, vascular autoantibodies AT1R and ETAR, and serum levels of 24 soluble serum factors were determined. For evaluation of the nailfold capillaroscopy microscopy characteristics, linear regression analysis accounting for age, sex, and diffusing capacity of the lungs for carbon monoxide percentage predicted was used. Autoantibodies and soluble serum factor levels were compared using two-sample t test with equal variances.Results: No statistically significant differences were observed in quantitative or qualitative nailfold capillaroscopy microscopy characteristics, or vascular autoantibody ETAR and AT1R titer between systemic sclerosis-pulmonary hypertension and systemic sclerosis-no pulmonary hypertension. In contrast, several serum levels of soluble factors differed between groups: Endostatin, sVCAM, and VEGFD were increased, and CXCL4, sVEGFR2, and PDGF-AB/BB were decreased in systemic sclerosis-pulmonary hypertension. Random forest classification identified Endostatin and CXCL4 as the most predictive classifiers to distinguish systemic sclerosispulmonary hypertension from systemic sclerosis-no pulmonary hypertension.Conclusion: This study shows the potential for several soluble serum factors to distinguish systemic sclerosis-pulmonary hypertension from systemic sclerosis-no pulmonary hypertension. We found no classifying potential for qualitative or quantitative nailfold capillaroscopy microscopy characteristics, or vascular autoantibodies.
tIn this study we aimed to identify genes that are responsive to pertussis toxin (PTx) and might eventu-ally be used as biological markers in a testing strategy to detect residual PTx in vaccines. By microarrayanalysis we screened six human cell types (bronchial epithelial cell line BEAS-2B, fetal lung fibroblastcell line MRC-5, primary cardiac microvascular endothelial cells, primary pulmonary artery smooth mus-cle cells, hybrid cell line EA.Hy926 of umbilical vein endothelial cells and epithelial cell line A549 andimmature monocyte-derived dendritic cells) for differential gene expression induced by PTx. Imma-ture monocyte-derived dendritic cells (iMoDCs) were the only cells in which PTx induced significantdifferential expression of genes. Results were confirmed using different donors and further extendedby showing specificity for PTx in comparison to Escherichia coli lipopolysaccharide (LPS) and Bordetellapertussis lipo-oligosaccharide (LOS). Statistical analysis indicated 6 genes, namely IFNG, IL2, XCL1, CD69,CSF2 and CXCL10, as significantly upregulated by PTx which was also demonstrated at the protein levelfor genes encoding secreted proteins. IL-2 and IFN- gave the strongest response. The minimal PTx con-centrations that induced production of IL-2 and IFN- in iMoDCs were 12.5 and 25 IU/ml, respectively.High concentrations of LPS slightly induced IFN- but not IL-2, while LOS and detoxified pertussis toxindid not induce production of either cytokine. In conclusion, using microarray analysis we evaluated sixhuman cell lines/types for their responsiveness to PTx and found 6 PTx-responsive genes in iMoDCs ofwhich IL2 is the most promising candidate to be used as a biomarker for the detection of residual PTx.
