Mast Cell Biomarker Predicts Severity of Dengue

A protein produced by mast cells in the immune system may predict which people infected with dengue virus will develop life-threatening complications.

Dengue virus (DENV) spread by mosquitoes, infects as many as 390 million people worldwide each year, and is a significant health issue in tropical areas of the world including parts of Latin America and Asia, and health professionals in Florida have reported cases in recent years.

Scientists at Duke University (Durham, NC, USA) working with their colleagues at Duke-National University of Singapore investigated the role of mast cells in attacking dengue virus in humans, and identified a biomarker derived from the mast cells, that appeared to predict the most severe cases of the disease in human patients.

Samples used for the investigation were derived from patients that ranged in age from 18 to 77 years, with a mean of 40 years; 42% of samples were obtained from females, and 58% from males. Dengue positive samples were determined based on physician diagnosis as well as molecular tests including reverse transcriptase polymerase chain reaction (RT-PCR) for viral ribonucleic acid (RNA).

The dengue fever (DF) and dengue hemorrhagic fever (DHF) patient sera used in this study were previously determined to be positive for serotypes 1, 2, or 3 by RT-PCR using the OneStep RT-PCR Kit (Qiagen; Valencia, CA, USA). Enzyme-linked immunosorbent assay (ELISA) kits for the human mast cell biomarker chymase, a serine protease, were obtained from Antibodies-Online (Atlanta, GA, USA).

Patients that were diagnosed with DF or DHF showed chymase levels in serum obtained during the acute phase of infection were significantly higher than levels in the serum of either healthy controls or individuals with fever that were DENV negative by RT-PCR. DF patients displayed an increase in serum chymase that was approximately 10 times higher than in healthy individuals or DENV-negative patients while, in DHF patients, chymase levels 30 times higher than healthy controls were detected.

Soman N. Abraham, PhD, a professor at Duke University and the senior author of the study, said,” In addition to revealing a potential new way to diagnose and treat dengue infections, these finding may have much broader applicability for other infectious diseases where vascular leakage is a major pathologic outcome.” The study was published on April 30, 2013, in the journal eLife.

Related Links:
Duke University
Duke-National University of Singapore
Antibodies-Online