title: Evaluation of FcγRIIIB-NA1/NA2 Polymorphism in Visceral Leishmaniasis.
abstract: BACKGROUND
  Several lines of evidence demonstrating that innate and adaptive immunity play important roles in the defense against visceral leishmaniasis (VL). A polymorphism within the FcγRIIIB gene can lead to the expression of three variants of NA1, NA2, and the combined one (NA1/NA2) which alters affinity of IgG to its receptor.
  
  
  OBJECTIVE
  The main aim of this study was to evaluate the FcγRIIIB-NA1/NA2 polymorphism in the FcγRIIIB gene of VL patients in comparison to healthy controls.
  
  
  METHODS
  In this cross-sectional study, three groups; 54 seropositive patients with clinical presentation of VL (group 1), 104 seropositive patients without clinical presentation (group 2), and 104 healthy controls (group 3) were evaluated with respect to the FcγRIIIB-NA1/NA2 polymorphism using a PCR-SSP method. The titration of anti-leishmania antibodies was analyzed using an immunoflorescence technique.
  
  
  RESULTS
  Our results indicated that polymorphisms within the FcγRIIIB gene (that lead to the expression of the NA1/NA2 isoforms) are significantly associated with VL. The results demonstrated that the genotype heterozygotic for FcγRIIIB-NA1/NA2 expression was significantly increased in VL patients, group 1 when compared to groups 2 and 3. Conversely, there is a decrease in homozygous NA1 and NA2 genotypes in VL patients; however, the overall frequency of NA1 and NA2 alleles appear similar across the three cohorts examined.
  
  
  CONCLUSIONS
  According to our results, it is likely that the increased frequency of the FcγRIIIB-NA1/NA2 genotype is associated with impaired immune responses against VL and its subsequent clearance from the patient.
authors.affiliation: Faculty of Medicine, Shahid Beheshti Hospital, Hamadan University of Medical Sciences, Hamadan, IR Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Abasi
authors.affiliation: Department of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran.
authors.forename: Pegah
authors.initials: P
authors.lastname: Lotfi
authors.affiliation: Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, IR Iran.
authors.forename: Ahad
authors.initials: A
authors.lastname: Bazmani
authors.affiliation: Department of Parasitology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran.
authors.forename: Mohamad
authors.initials: M
authors.lastname: Matini
authors.affiliation: Department of Immunology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, IR Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Hajilooi
keywords: Iran; Leishmaniasis, Visceral; Polymorphism, Genetic