Association of FCN2 polymorphisms and Ficolin-2 levels with dengue fever in Vietnamese patients

Int J Infect Dis. 2020 Jun;95:253-261. doi: 10.1016/j.ijid.2020.02.029. Epub 2020 Feb 20.


Background and objective: The human ficolin-2, encoded by FCN2, recognizes pathogen-associated acetylated residues on their cell surfaces and activates the lectin complement cascade. This study aimed to investigate the contribution of human ficolin-2 and the functional FCN2 genetic variants in dengue virus (DENV) infection and in clinical progression.

Methods: FCN2 genetic polymorphisms in the promoter, intron 7 and exon 8 were genotyped in 279 patients with dengue fever and in 200 healthy controls by direct Sanger sequencing. The ficolin-2 levels were measured in serum samples by ELISA and correlated with clinical data.

Results: The frequencies of +6031GG, +6220GG and +6424TT genotypes were significantly higher in dengue patients compared to healthy controls indicating an increased risk of dengue fever. The SNPs rs11103563 (+6031A/G), rs7872508 (+6220 T/G), and rs7851696 (+6424G/T) significantly regulated ficolin-2 levels in dengue patients (P < 0.0001). Ficolin-2 levels were increased in patients with dengue and Dengue with Warning Signs (DWS) compared to healthy controls (P < 0.0001 and P = 0.038, respectively). Ficolin-2 levels were significantly increased after 10-14 days of admission in both dengue and DWS patients and then slightly decreased after three weeks of discharge, indicating that ficolin-2 levels were modulated during the progression of dengue fever. In addition, ficolin-2 levels were negatively correlated with AST levels and positively correlated with platelet counts.

Conclusions: FCN2 polymorphisms are associated with dengue fever in the Vietnamese population. Ficolin-2 levels are modulated during the progression of dengue fever and correlated with clinical parameters and thus may play a possible role in the pathogenesis of DENV infection.

Keywords: DENV infection; Dengue fever; FCN2; Ficolin-2; Severe dengue; polymorphism.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Dengue / genetics
  • Dengue / metabolism*
  • Dengue Virus / genetics
  • Disease Progression
  • Female
  • Genotype
  • Humans
  • Lectins / genetics
  • Lectins / metabolism*
  • Male
  • Middle Aged
  • Polymorphism, Single Nucleotide
  • Promoter Regions, Genetic
  • Vietnam
  • Young Adult


  • Lectins
  • ficolin