Maheshi Mapalagamage
University of Colombo, Sri Lanka
Title: Potential Use of Total Serum Nitrite and Nitrate (NOx) Level in Dengue Patients as a Prognostic Marker of Dengue Hemorrhagic Fever
Biography
Biography: Maheshi Mapalagamage
Abstract
Use of total nitrite plus nitrate (NOx) and nitrite (NO2−) separately as surrogate markers for serum nitric oxide in severe dengue and their longitudinal changes along with the progression of infection was studied. Deproteinized sera from confirmed dengue fever (DF, n=145) and dengue hemorrhagic fever (DHF, n=74) patients on admission-A, critical-C, discharge-D, and convalescence-CON stages and from age-gender matched healthy individuals (HC, n=77) were taken to assess NO2− and NOx levels using Griess and modified Griess assays. Serum NOx in DHFA was significantly lower compared to DFA (p<0.001). HC had the lowest NOx and NO2− compared to all patient categories (p<0.001) except NO2− in DF-CON and DHF-CON and NOx in DHF-CON. A strong significant positive correlation between serum NOx levels and NO2- was observed in DHFA (p<0.000, r=0.599, Pearson correlation), DHFC (p<0.004, r=0.573) and DHFD (p=0.425, r=0.008) patient categories. Receiver operating characteristic (ROC) curve analysis was done to seek the prognostic value the test of serum NOx in predicting DHF on admission. Serum NOx and NO2− in DHF patients admitted on fever day 3 (DHFA-3) was significantly lower compared to DFA-3 (p<0.050). Cut-off values of 4.46 μM for NOx (91.3% sensitivity and 80.1% specificity) and 1.25 μM for NO2− (75.0% sensitivity and 73.3% specificity) were obtained for day 3 of fever. In DHF patients, the lower NO levels may have made a more favorable environment for the virus to flourish. This may have resulted in a high viral load which may have increased the adverse pathophysiologic process in the body leading to increased severity.Therefore, Serum NOx may be used as potential prognostic marker of DHF in patients presenting with DF in the early stage (on day 3 of fever) of the disease.