Actividad sérica de la acetilhidrolasa del factor activador de plaquetas en pacientes afrodescendientes y mestizos con dengue, Colombia

Abstract

Introduction: Severe dengue infection is characterized by enhanced vascular permeability produced by cytokines and biochemical mediators. One of these mediators is the platelet-activating factor.Degradation of platelet-activating factor is accomplished by its specific acetylhydrolase. Down or up regulation of this enzyme has been linked to several diseases. However, the role of this enzyme in dengue infection is unknown, a well as whether differential activity occurs by ethnic group. Objective: The activity of the platelet-activating factor-acetylhydrolase was compared in patients infected with dengue virus in two ethnic groups.Material and methods: A descriptive, prospective and longitudinal study was made in two states of Colombia (Antioquia and Chocó). Serum samples were taken from 43 mestizo patients and 33 patients of African descent, each taken during five consecutive days of the acute dengue phase. A second serum sample was taken during the convalescent phase.Results: The mestizo patients showed higher frequency of dengue hemorrhagic fever than the patients of African descent (23.3% vs. 12.1%, p=0.25). The serum activity of the platelet-activating factor acetylhydrolase was higher in African descendents than in mestizos (0.89, CI: 0.72-1.10 vs. 0.76 CI: 0-1.03, p<0.001). This relationship is maintained for occurence of dengue fever (0.89, CI: 0.73-1.10 vs. 0.73, CI: 0-1.05, p<0.001), but not significant for dengue hemorrhagic fever (0.88, CI: 0.69-1.12 vs. 0.83, CI: 0.71-1.08, p=0.89).Conclusion. An increased production of platelet-activating factor-acetylhydrolase occurs in the serum of dengue-infected African descendants. However, a study of the frequencies of polymorphisms for this enzyme will permit more conclusive support for these observations.Introduction. Severe dengue infection is characterized for enhanced permeability vascular, produced for cytokines and chemical mediators. One of these is the platelet-activating factor. Platelet-activating factor-acetylhydrolase is the enzyme responsible of its degradation. Down or up regulation of this enzyme has been linked to several diseases. However the role of this enzyme in dengue infection is still unknown, nor is known whether there is differential activity according to ethnic group.Objective. To compare the activity in serum of the platelet-activating factor-acetylhydrolase in patients infected with dengue virus in two ethnic groups.Material and methods. A Descriptive, prospective and longitudinal study was made in two states of Colombia. To 43 mestizo patients and to 33 afro-descendent patients with dengue infection was taken a serum sample during five consecutive days in acute phase and other serum sample was taken in convalescent phase.Results. The mestizo patients showed higher frequency of cases of dengue hemorrhagic fever that the afro-descendant patients (23.3% vs. 12.1%, p=0.248). The activity in serum of the platelet-activating factor acetylhydrolase (median (25 percentile and 75 percentile) was higher in afro-descendents than in mestizos (0.89 (0.72-1.10) vs. 0.76 (0-1.03), p=0.000). These behaviors are preserved for dengue fever (0.89 (0.73-1.10) vs. 0.73 (0- 1.05), p=0.000) and dengue hemorrhagic fever 0.88 (0.69-1.12) vs. 0.83 (0.71-1.08), p=0.893).Conclusion. These findings show increased production of platelet-activating factor-acetylhydrolase in the afro-descendants. However, it is necessary development studies of polymorphisms of this enzyme which would give conclusive results.