Researchers at the National Institutes of Health have found that a novel blood test can be used to easily evaluate disease severity in patients with pulmonary arterial hypertension (PAH) and predict survivability. In early clinical studies, the researchers showed the test to significantly improve upon conventional tests, some of which use invasive tools.
The new blood test measures DNA fragments shed by damaged cells. Researchers found that these fragments, called cell-free DNA, were elevated in the blood of patients with PAH and increase with disease severity. If future studies confirm the findings, this blood test for PAH patients could allow doctors to intervene faster to prevent or delay progression of the disease and possibly save lives. Cell-free DNA is a relatively new analytical technique that is growing in its potential medical uses, which include the early detection of heart- and lung-transplant rejection as well as early detection of cancer.
The findings will appear online in the journal Circulation, a publication of the American Heart Association.
In the current study, the research team analyzed cell-free DNA from blood samples taken from 209 adult patients, predominately women, diagnosed with PAH at two large U.S. medical centers. The researchers compared the results to cell-free DNA measured from a control group of 48 healthy volunteers without PAH at the NIH Clinical Center.
They found that cell-free DNA was elevated in patients with PAH, and also found that cell-free DNA concentrations increased in proportion to the severity of the disease. Patients with the highest level of cell-free DNA had a 3.8 times greater risk of either death or a need for lung transplantation compared to those with the lowest level of cell-free DNA, the researchers said.
Further analyses of cell-free DNA samples revealed that multiple tissue types – including the heart, blood vessels, fat tissue, and inflammatory cells circulating in the blood – were affected by PAH. The new blood test will allow researchers to better pinpoint the specific tissues involved in the PAH disease process. This knowledge may lead to new drug interventions for PAH, whose current treatment options may slow but not halt or reverse disease progression.
