title: IL-17 level in patients with Dengue virus infection & its association with severity of illness.
abstract: BACKGROUND
  Clinical symptoms of Dengue vary from mild febrile illness to severe infection. A potent pro-inflammatory cytokine, IL-17, secreted by mainly Th17 cells mediate inflammation and autoimmune diseases. Role of IL-17 in pathogenesis of dengue virus (DV) infection is not clear.
  
  
  METHODS
  Total 211 dengue patients and 70 healthy controls were enrolled. IL-17 level was tested in serum samples from all cases and controls. Cases were grouped as either dengue or severe dengue; based on WHO (2009) classification. Anti DV IgG antibody detection and DV serotype specific PCR were also done. Levels of IL-17 in dengue and severe dengue patients, primary and secondary DV infection were compared. Association of DV serotypes with severity of illness and various clinical and laboratory features with IL-17 levels were analyzed.
  
  
  RESULTS
  Of total 211cases, 90 and 121cases were presenting as dengue and severe dengue illness, respectively. Levels of IL-17 were significantly higher in dengue patients as compared to control. Mean level of IL-17 was higher in severe cases than non severe cases; however difference was not statistically significant. Stratified analysis of IL-17 level in different age group showed significantly high IL-17 levels in children with severe dengue. Mean level of IL-17 was also significantly higher in cases with secondary DV infection in comparison to primary DV infection. Levels of IL-17 were higher in patients with DV-2 infection in comparison to cases with DV-1 and DV-3 infection. Significant positive association of high IL-17 levels was seen with pleural effusion and respiratory distress.
  
  
  CONCLUSIONS
  IL-17 appears to be associated with severe DV infection. It is very important to understand the exact role of IL-17 in the pathogenesis of severe DV infection.
authors.affiliation: Department of Microbiology, K. G. Medical University, Lucknow, 226003, India. amita602002@yahoo.com
authors.forename: Amita
authors.initials: A
authors.lastname: Jain
authors.forename: Nidhi
authors.initials: N
authors.lastname: Pandey
authors.forename: R K
authors.initials: RK
authors.lastname: Garg
authors.forename: Rashmi
authors.initials: R
authors.lastname: Kumar
mesh_terms: D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood / Q000276:immunology; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000097:blood* / Q000276:immunology*; D003716:Dengue Virus / Q000145:classification / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007223:Infant; D007231:Infant, Newborn; D020381:Interleukin-17 / Q000097:blood*; D008875:Middle Aged; D012703:Serotyping; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D020381:Interleukin-17