Is liver damage dependent on the serotype of dengue virus? - A study in Mexico

The prevalence of dengue in Mexico and the participation of the four serotypes make the correct handling of the disease a difficult task. Dengue-infected people will probably present different clinical profiles depending on the dengue serotypes and genotypes. As a consequence, both diagnosis and treatment will become difficult. Administration of paracetamol, for instance, could increase liver damage. The aim of this study was to analyse whether liver damage is being reported in patients suffering from dengue virus infection, and if the severity of the damage depends on the infecting serotype. To correlate the clinical observations, a parallel study was carried out in BALB/c mice infeted with each of the four serotypes. Eighty-four serum samples from clinically-diagnosed dengue patients were collected from 13 endemic areas of Mexico. Ten (unless otherwise stated) serum samples of each available serotype were tested for the three main liver transaminases, aspartate aminotransferase (AST), alanine-aminotransferase (ALT) and lactate dehydrogenase (LDH). To test the same on animal model, four groups of mice were infected with each of the four dengue virus serotypes and a non-infected group of mice was included as a control. From these animals, the livers were excised and weighted to look for hepatomegaly and their sera were collected to measure the levels of AST, ALT and LDH. The dengue serotype was assessed by RT-PCR, which clearly established a correlation between liver damage and DENV-2, 1 and 3 in that order, based on the AST enzyme activity. In the case of infected mice, higher liver damage, based on liver size and AST activity, were observed for DENV-2, 1, 3 and 4. Based on these findings, it is strongly suggested to establish a compulsory check-up of dengue patients in regard to their liver enzyme profiles before administering paracetamol.