A Mumbai-based study on to track dengue biomarkers can help curb deaths drastically
Ever wondered why one dengue patient recovers at home with simple symptomatic line of treatment while another may battle for life in an intensive care unit (ICU) with severe complications? The extremely varied prognosis of the mosquito-borne disease has intrigued the medical fraternity for a long time.
Tracking dengue biomarkers
To find answers, the civic-run Polymerase Chain Reaction (PCR) Laboratory at Arthur Road in Mumbai has tied up with the Indian Institute of Technology, Bombay to track down some biomarkers in order to predict how dengue will progress in a particular patient. If all goes well, these biomarkers can drastically change the disease management and help in curbing dengue deaths.
“The idea is to establish molecular signatures for complicated dengue cases and thus have sound knowledge of the disease progression in different individuals suffering from the disease,” says Dr. Jayanthi Shastri, head of the PCR laboratory. The study will commence this month as dengue cases increase during the monsoon season. “We will collect about 100 to 150 samples of which half will be of dengue patients who required ICU admission,” she adds.
Dengue is spread through the bite of an infected female Aedes aegypti mosquito. While it causes flu-like symptoms such as high fever, rashes, severe body ache, etc. in its severe form, Dengue Hemorrhagic Fever (DHF) can lead to lethal complications. DHF in its severe form causes Dengue Shock Syndrome, a dangerous complication that is associated with very high mortality rate as the blood pressure drops down drastically and organs start to collapse.
Dengue prevalence in India
The first evidence of occurrence of dengue in India was reported in 1956 from Vellore district in Tamil Nadu. The first DHF outbreak is said to have occurred in West Bengal in 1963. A disease that was known for its presence only in urban areas gradually spread across the country.
In 1996, one of the most severe outbreaks of dengue occurred in Delhi when 10,252 cases and 423 deaths were reported. In 2006, the country witnessed another outbreak with 12,317 cases and 184 deaths reported overall. According to the National Vector Borne Disease Control Programme (NVBDCP), in 2015, 99,913 dengue cases and 220 deaths were reported from the country. In 2016, the number went up to 1,29,166 cases and 245 deaths. This year so far, 11,402 cases and 11 deaths have been reported till the month of May.
“Not all dengue cases develop in DHF or DSS. So the question is when and why does the disease progress badly in some individuals and develop into severe disease. Through our study, we aim to identify a panel of protein biomarkers that can find us these answers and help in prediction of severity,” says Dr. Sanjeeva Srivastava, associate professor and group leader of the proteomics laboratory at IIT Bombay. Biomarkers are indicators that help in determining the presence or severity of the disease.
A potential game changer
According to Dr. Srivastava, the aim is to eventually develop a diagnostic kit that will help doctors in deciding the line of treatment to avoid severe disease progression. Dr. Srivastava has been working on febrile (fever-based) infectious illnesses and his laboratory already has identified a range of protein profiles in malaria, which has been published in Scientific Reports, the open-access journal published by Nature. “As and when we start getting the dengue samples, we will work towards finding a link between the proteins and dengue severity,” says Dr. Srivastava.
Explaining the process, he says serum from the blood samples of patients is separated at first. The next stage involves extraction of the proteins, which are thoroughly analysed using high-throughput proteomic technologies such as mass spectrometry. “Thereafter, the protein expressions are studied to see if there is a specific pattern in mild and severe cases,” he says, adding that a similar analysis was carried out to identify falciparum and vivax malaria and understand why the mechanism varies in the two forms of the disease.
Clinicians feel that if a predictive test comes in place, it will be a game changer, especially during the monsoon season when the patient load is very high. “Knowing well in advance how a disease will progress will bring down unnecessary hospitalisations too,” says Mumbai-based physician Dr. Pratit Samdani citing an example of a test called ‘immature platelet fraction’ that helps tell if a patient will generate new platelet on his or her own. “It helps in avoiding unnecessary platelet transfusion.”