Prospective Study for the Evaluation of Dengue Prognostic Biomarkers in Singapore
Condition: Dengue Hemorrhagic Fever; Dengue Shock Syndrome; Severe Dengue
MeSH terms: Dengue; Hemorrhagic Fevers, Viral; Severe Dengue; Shock
Study type: Observational

Summary: 
      World Health Organisation (WHO) has identified Dengue as the fastest spreading mosquito-borne
      disease in the world. This study follows on from the National Medical Research Council STOP
      Dengue Translational and Clinical Research flagship grant. Differential serum concentrations
      of alpha2-macroglobulin (A2M), chymase (CMA1) and vascular endothelial growth factor A
      (VEGFA) were discovered to accurately identify dengue patients who will develop severe
      disease from those who will not, prior to the development of severe complications. By
      identifying patients at risk of developing severe disease in advance, these patients can be
      monitored more closely to provide more timely fluid interventions, and hopefully further
      reduce fatality rate. At the same time, more patients who are not at risk can be managed as
      outpatients to further minimize unnecessary hospitalization costs and wastage of healthcare
      resources. After discovery of the Dengue prognostic biomarkers, a multivariate logistic
      regression predictive model was built from a small retrospective derivative cohort (50
      subjects), followed by validation using a small prospective validation cohort (50 subjects).
      The model had a receiver operating characteristic (ROC) curve AUC (area under the curve) of
      0.944, and a sensitivity and specificity of 90% and 91% during validation, respectively. The
      premise of this study is to validate our observations in a larger prospective cohort (200
      subjects). At the same time, we would like to better understand the characteristics of the
      Dengue prognostic biomarkers, especially whether there are situations in which the biomarkers
      cannot predict Dengue Haemorrhagic Fever (DHF)/ Dengue Shock Syndrome (DSS) and/or Severe
      Dengue (SD) and how the biomarkers can further improve the cost-effectiveness of the clinical
      management of Dengue patients.
    

Detailed description: 
      This is a non-interventional, prospective study aim to recruit 200 subjects from National
      University Hospital, Tan Tock Seng Hospital and Ng Teng Feng General Hospital over a period
      of 2 years to determine whether differential serum A2M, CMA1 and VEGFA concentrations can
      predict whether a dengue patient will develop severe disease. Serum A2M, CMA1 and VEGFA
      concentrations will be quantitated using enzyme-linked immunosorbent assays. The objectives
      of this study as below:

        1. Determine the optimum cut-off for the prediction of DHF/DSS (WHO 1997 classification)
           and Severe Dengue (SD; WHO 2009 classification).

        2. Better understand the characteristics (e.g. daily kinetics) of A2M, CMA1 and VEGFA in
           Dengue and how their serum concentrations are affected by other variables e.g. patient
           age and gender, day of sample collection, primary/secondary infection (based on patient
           memory and/or Standard Diagnostics SD BIOLINE Dengue Duo) and virus serotype.

        3. Perform a cost-effectiveness analysis for the adoption of such a Dengue prognostic
           technology in hospital.

      Eligible participants will be aged 21 and above with a laboratory confirmed dengue patients
      (either positive PCR or positive NS1), and meet all inclusion/exclusion criteria. Each
      participant will be given an information sheet and informed consent obtained from him/her.
      Blood will be drawn for PCR Dengue serotyping and measurements of serum concentrations of
      A2M, CMA1 and VEGFA via quantitative enzyme-linked immunosorbent assays (ELISA). Blood
      collection will be performed on the day of recruitment.

      Participants may be managed as inpatients or outpatients as decided by their treating
      physician. For participants who are managed as Dengue outpatients, they will be asked to
      return to the outpatient clinic every day. For both Dengue inpatient and outpatient
      participants, blood will be drawn every day until they are discharged from care or Day 7 of
      the study, whichever earlier. If the participants are discharged from care (discharge from
      hospital or dengue clinic) on the day of recruitment, they will be asked to come back for
      study visit on Day 2. And 2 ml of blood will be collected for research purpose on Day 2. On
      the day of discharge, for both Dengue inpatients and outpatients, participants will each be
      given a questionnaire to complete. A separate questionnaire will also be filled up by the
      study team for the discharge of each Dengue inpatient participant. Should the participant be
      discharged prior to Day 7 of the study, a telephone call will be made to the discharged
      participant on Day 7 of the study to establish his/her health status. Upon completion of the
      study, each participant will be reimbursed a lump sum of $50.

      Data collected will be entered into a paper case report forms and will be transcribed onto
      eCRF. All participants identifiers will not be collected. The system will allow for audit
      tracking. During the course of the study, auditors from relevant authorities may visit the
      study site to review protocol compliance, check electronic case report form (eCRFs) and
      ensure that the study is being conducted according to Good Clinical Practice (GCP).
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Participants will be recruited from patients presenting themselves to the emergency
        departments, outpatient clinic or inpatient wards of the participating sites, and who are
        diagnosed by laboratory tests to be infected with Dengue. Delegated research staff will
        screen laboratory-confirmed dengue patients with inclusion/exclusion criteria. Each
        participant will be given an information sheet and informed consent will obtained from
        him/her before any study procedures.
      
Biospecimen description: 
      plasma and serum sample will be stored if patient agreeable to keep for future research.
    
Keywords: Dengue