Re: “Genetic Polymorphisms of Tumor Necrosis Factor Alpha and Susceptiblity to Dengue Virus Infection in a Mexican Population” by Sánchez-Leyva et al. (Viral Immunol 2017;30:615–621)

To the Editor,

Dengue is an important tropical disease. The immunopathogenesis in dengue is very interesting. According to a recent report by Sánchez-Leyva et al., it was concluded that “Our results suggest a minimal effect of the −308 and −238 TNF-α gene polymorphisms in dengue patients and that their increased serum levels of TNF-α are independent of genotypes (3).” Indeed, this result might be expected since there is no clear evidence on the role of tumor necrosis factor (TNF) in dengue susceptibility (2) but severity (1). In fact, the increased TNF might be a clue for occurrence of increased vascular permeability and fluid leakage in dengue (1) and it is the general process relating to several chemokines (1). An important factor that Sánchez-Leyva et al. might not concern is the management of the patients. The early diagnosis and management of dengue by proper fluid therapy usually result in a good clinical outcome (4). Without consideration on the clinical management of the case, the relationship between studied genetic polymorphism and clinical outcome hemorrhagic fever might not be valid.