Johns Hopkins Children's Center cardiologist Allen Everett recently won more than $460,000 in stimulus grant funding to identify the biomarkers of idiopathic pulmonary hypertension (IPH), a progressive and highly lethal condition in children and adults marked by persistently elevated pressure in the artery that carries blood from the heart to the lungs.
Biomarkers — biological "byproducts" or "footprints" of disease — are substances that can be measured in bodily fluids or tissues to provide clues about disease presence and activity. Like antibodies, classic biomarkers that are evidence of exposure to viruses and bacteria or proof of immunity following vaccination, biomarkers for IHP would allow physicians to better monitor disease progression and response to treatment.
"A measurable, reliable biomarker to follow the patient's response to medication, could tell us who's benefitting and who's not, help us predict how well the patient will do and tells us if we should tweak the dose for a better effect," Everett says.
Currently, the most common way to track the course of IPH is an echocardiogram — an ultrasound image of the heart and the pulmonary artery — but the test is time-consuming, expensive and subject to misinterpretation. Perhaps more importantly, researchers say, there is no objective and accurate way for doctors to follow how well the patient is responding to medications.
IPH patients are treated with vasodilators that expand and relax blood vessels to improve blood flow and ease pressure in the pulmonary artery and the heart. However, up to 30 percent of patients do not respond to treatment, and nearly 70 percent of those who don't respond die within five years of diagnosis, researchers say.