[New evidence in the susceptibility to dengue infection associated to HH polymorphism of FcgammaRIIa receptor].

Introduction: polymorphic variants of FcgammaRIIa receptor have been associated to susceptibility to develop several infectious diseases. The relationship between the polymorphism of this receptor and the susceptibility to dengue hemorrhagic fever was recently reported.

Objectives: to explore whether the association of the homocygotic variants of the receptor to susceptibility to or protection from a disease could be also related with the IgG antibody titters and the exposure to a number of infections.

Methods: a retrospective analytical study was performed on individuals who had been infected with the dengue virus 4 during the 2006 epidemic in the City of Havana and were tracked down in 2008. A total number of 97 individuals were recruited of whom 68 had suffered dengue fever and 29 had had dengue hemorrhagic fever. A 10-mL blood sample was taken from each of them and then placed in EDTA anticoagulant for DNA isolation and 5 mL placed in dry tubes to obtain serum. The genetic polymorphism of FcgammaRIIa receptor, the total anti-dengue IgG antibody titers and the antecedent of dengue infection were determined.

Results: it was interesting to note that there was very significant direct relation (p< 0.0001) between high anti-dengue IgG antibodies titers and the number of infections suffered by these people. This behaviour was present in those individuals with the HH homocygotic variant.

Conclusion: it seems that those individuals with polymorphism in FCgammaRIIa-H/H receptor would tend to non-elimination of IgG antibodies through this receptor, which is associated to the number of infections suffered by the individual.