Sep 10 2015
By Eleanor McDermid, Senior medwireNews Reporter
Two members of the vascular endothelial growth factor (VEGF) family are highly specific and moderately sensitive for the presence of pulmonary hypertension, report researchers.
Of the two VEGF signalling components, placental growth factor (PlGF) was more sensitive for pulmonary hypertension, while soluble fms-like tyrosine kinase 1 (sFlt-1) was more specific. When combined, the biomarkers had a sensitivity of 62.4% and specificity of 100%, at respective thresholds of 29.2 pg/mL and 5753 pg/mL.
This makes the biomarkers “reasonably suitable screening tools”, say Ardeschir Ghofrani (Universities of Giessen and Marburg Lung Center, Germany) and co-researchers; “however, their main strength lies in their almost unfailing specificity.”
The study included 247 patients, comprising 62 with idiopathic pulmonary arterial hypertension (PAH), 14 with associated PAH, 21 with collagen vascular disease, 26 with pulmonary venous hypertension, 67 with lung disease-associated pulmonary hypertension and 57 with chronic thromboembolic pulmonary hypertension. They were compared with 40 patients in whom pulmonary hypertension was ruled out on right heart catheterisation, despite suggestive symptoms.
The combined biomarkers were slightly more sensitive in PAH patients (idiopathic and associated PAH and collagen vascular disease) than in the pulmonary hypertension group as a whole, at 83.7%, while maintaining their 100% specificity.
Unlike the established prognostic biomarker brain natriuretic peptide, PlGF and sFlt-1 were not associated with disease severity or patient outcomes.
This suggests that the VEGF signalling molecules have “a pathological role that is not directly linked to the increased pressure in the pulmonary vasculature and the resulting changes of the right ventricle”, writes the team in the European Respiratory Journal.
Ghofrani et al stress that invasive testing remains necessary in the case of a negative biomarker test if other non-invasive tests are indicative of pulmonary hypertension, and is also necessary for diagnostic classification and to assess severity.
However, they believe that “sFlt-1 and PlGF may become useful additional parameters which help to decide whether or not invasive assessment by means of right heart catheterisation is required.”
They also note that the high specificity of these biomarkers may help to avoid misdiagnosis of pulmonary hypertension when other non-invasive tests are negative.
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