title: Haptoglobin gene polymorphisms and interleukin-6 and -8 levels in patients with sickle cell anemia.
abstract: BACKGROUND
  Haptoglobin genotypes, and interleukin-6 and -8 participate in the pathophysiology of sickle cell anemia. The expression of cytokines is regulated by genetic mechanisms however the effect of haptoglobin polymorphisms on these cytokines is not fully understood. This study aimed to compare the frequency of haptoglobin genotypes and the interleukin-6 and -8 concentrations in sickle cell anemia patients and controls to investigate the association between haptoglobin genotypes and cytokine levels.
  
  
  METHODS
  Sixty sickle cell anemia patients and 74 healthy individuals were analyzed. Haptoglobin genotypes were determined by multiplex polymerase chain reaction, and the interleukin-6 and -8 levels by enzyme linked immunosorbent assay. The association between haptoglobin genotypes and cytokines was investigated by statistical tests.
  
  
  RESULTS
  Hp2-1 was the most common genotype in both the cases and controls while Hp1-1 was less frequent among sickle cell anemia patients. Interleukin-6 and -8 levels were higher in patients than controls (p-value <0.0001). There was no significant difference in interleukin-6 and -8 concentrations between the genotypes (p-value >0.05). A similar trend was observed among the controls.
  
  
  CONCLUSIONS
  Although, levels of interleukin-6 and -8 were higher in the sickle cell anemia patients, they appeared not to be related to the haptoglobin genotypes. Further investigations are necessary to identify factors responsible for increased secretion of the interleukin-6 and -8 pro-inflammatory cytokines in patients with sickle cell anemia.
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Bruna Spinella
authors.initials: BS
authors.lastname: Pierrot-Gallo
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Perla
authors.initials: P
authors.lastname: Vicari
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Sandra Satiko
authors.initials: SS
authors.lastname: Matsuda
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Samuel Ademola
authors.initials: SA
authors.lastname: Adegoke
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil.
authors.forename: Grazielle
authors.initials: G
authors.lastname: Mecabo
authors.affiliation: Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brazil. Electronic address: stella.figueiredo@unifesp.br.
authors.forename: Maria Stella
authors.initials: MS
authors.lastname: Figueiredo
keywords: Genotype; Haptoglobin polymorphism; Interleukins; Sickle cell anemia