Actividad sérica de la acetilhidrolasa del factor activador de plaquetas en pacientes afrodescendientes y mestizos con dengue, Colombia / Serum platelet-activating factor acetylhydrolase activity in dengue patients of African or mestizo descendency

Introducción. El dengue grave se caracteriza por el aumento de la permeabilidad vascular inducida por citocinas y mediadores químicos; uno de estos es el factor activador de plaquetas. La acetilhidrolasa del factor activador de plaquetas es la enzima responsable de su degradación, y su deficiencia o aumento se ha relacionado con varias enfermedades. Sin embargo, su papel en la infección por dengue es poco conocido, como tampoco se sabe si existe diferente actividad según el grupo étnico. Objetivo. Comparar la actividad en suero de la acetilhidrolasa del factor activador de plaquetas en dos grupos étnicos con infección por el virus del dengue. Materiales y métodos. Se llevó a cabo un estudio descriptivo, longitudinal, prospectivo, en dos departamentos de Colombia, Antioquia y Chocó. A 43 pacientes mestizos y a 33 pacientes afrodescendientes con diagnóstico de dengue, se les tomó una muestra de suero por cinco días consecutivos en la fase aguda y una muestra en la de convalecencia. Resultados. Se observó mayor frecuencia de casos de dengue hemorrágico en los pacientes mestizos que en los afrodescendientes (23,3 % Vs. 12,1 %, p=0,248). La actividad sérica de la acetilhidrolasa del factor activador de plaquetas (mediana, percentil 25 y percentil 75) fue más elevada en afrodescendientes que en mestizos (0,89 (0,72-1,10) Vs. 0,76 (0-1,03), p=0,000). Este comportamiento se conserva en el dengue clásico (0,89 (0,73-1,10) Vs. 0,73 (0-1,05), p=0,000) y en el hemorrágico (0,88 (0,69-1,12) Vs. 0,83 (0,71-1,08), p=0,893). Conclusiones. Se encontró mayor producción de acetilhidrolasa del factor activador de plaquetas en los pacientes afrodescendientes. Sin embargo, es necesario hacer estudios de polimorfismos de esta enzima que permitan obtener resultados concluyentes.

Aminotransferasas séricas en pacientes con Dengue tipo 3 / Aminotransferases serum levels in patients with Dengue type 3

Background: Dengue infections may affect the liver, causing inflammation and compromising its function. Aim: To determine serum aminotransferases in patients with Dengue. Material and methods: One hundred eighty four patients with Dengue confirmed with anti-Dengue IgG and IgM antibodies measured by ELISA, aged 1 month to 79 years, were studied. As controls, 40 patients with acute hepatitis B virus infection aged 11 to 59 years and 40 healthy individuals, aged 14 to 55 years, were also studied. Alanine and aspartate aminotransferases (ALT and AST) were determined using a colorimetric method. Results: Sixty one percent of patients with Dengue had elevated aminotransferase levels. In patients with Dengue and hepatitis B, mean ALT levels were 21.3±8.4 and 29.7±18.8 U/I, respectively. Mean AST values were 37.3±19, 19.6± 16.4 and 4.3±1.7 U/I in patients with Dengue, hepatitis B and controls, respectively. During the year 2001, there was an increase in the number of cases with hemorrhagic fever caused by Dengue and 65 percent had elevation of aminotransferases. Conclusions: An increase in aminotransf erase levels is common in patients with Dengue.

The impact of dengue on liver function as evaluated by aminotransferase levels

The objective of this study was to evaluate the impact of dengue virus infection on liver function by measuring aminotransferase in blood samples from patients serologically diagnosed by according to two MAC-ELISA protocols. Degrees of liver damage were classified according to aminotransferase levels: grade A - normal enzyme levels; grade B - increased levels of at least one of the enzymes; grade C - increased, with at least one of the enzymes being at levels higher than three times the upper reference values; grade D - acute hepatitis, with aminotransferase levels at least ten times their normal values. Of the 169 serologically confirmed cases of dengue at the dengue referral center in Campos dos Goytacazes in the state of Rio de Janeiro, Brazil, 65.1 percent had abnormal aminotransferase levels: 81 cases being classified as grade B, 25 as grade C and 3 as grade D. A further 34.9 percent of cases had normal enzyme levels and were classified as grade A. Liver damage is a common complication of dengue infection and aminotransferase levels are a valuable marker for monitoring these cases.

Correlación entre los niveles de glutatión peroxidasa, un marcador de estrés oxidativo, y la presentación clínica del dengue / Association between glutathione peroxidase levels and clinical manifestations of dengue

Background: Glutathione peroxidase (GP) can be used as a marker of oxidative stress in infectious diseases. Aim: To evaluate the association between the levels of glutathione peroxidase (GP) and the manifestations and complications of dengue. Patients and Methods: Between April 2003 and December 2004, 161 patients with dengue were prospectively evaluated. In the first evaluation, within 48 and 96 hours of disease onset, a plasma sample was obtained to measure the GP levels. The association between GP levels, clinical manifestations and complications was evaluated during the follow up. Results: Mean GP values were 1198 U/L (95 percent confidence interval 1089-1306). Values greater than 1200 U/L were associated with headache, arthralgias and increased heart rate. There was a negative association between GP levels and serum triglycerides. During follow up, patients with GP >1200 U/L had a higher frequency of spontaneous hemorrhages. In a logistic regression analysis arthralgias, fever and increased heart rate, were independently associated with levels >1200 U/L. Conclusions: GP levels was associated to some of the manifestations of dengue. This finding suggests that the intensity of oxidative stress can influence the clinical presentation of dengue.