title: Correlation of low levels of nitrite and high levels of fetal hemoglobin in patients with sickle cell disease at baseline.
abstract: BACKGROUND
  Sickle cell disease is a hemoglobinopathy characterized by hemolytic anemia, increased susceptibility to infections and recurrent vaso-occlusive crises that reduces the quality of life of sufferers.
  
  
  OBJECTIVE
  To evaluate the correlation of the levels of lactate dehydrogenase, malonaldehyde and nitrite to fetal hemoglobin in patients with sickle cell disease not under treatment with hydroxyurea in outpatients at a university hospital in Fortaleza, Ceará, Brazil.
  
  
  METHODS
  Forty-four patients diagnosed with sickle cell disease were enrolled at baseline. Diagnosis was confirmed by evaluating the beta globin gene using polymerase chain reaction-restriction fragment length polymorphism. The concentration of fetal hemoglobin was obtained by high-performance liquid chromatography. Serum levels of nitrite, malonaldehyde and lactate dehydrogenase were measured by biochemical methods.
  
  
  RESULTS
  Significantly higher levels of lactate dehydrogenase, nitrite and malonaldehyde were observed in patients with sickle cell disease compared to a control group. The study of the correlation between fetal hemoglobin levels and these variables showed a negative correlation with nitrite levels. No correlation was found between fetal hemoglobin and malonaldehyde or lactate dehydrogenase. When the study population was stratified according to fetal hemoglobin levels, a decrease in the levels of nitrite was observed with higher levels of fetal hemoglobin (p-value = 0.0415).
  
  
  CONCLUSIONS
  The results show that, similar to fetal hemoglobin levels, the concentration of nitrite can predict the clinical course of the disease, but should not be used alone as a modulator of prognosis in patients with sickle cell disease.
authors.affiliation: Universidade Federal do Ceará - UFC, Fortaleza, CE, Brazil].
authors.forename: Darcielle Bruna Dias
authors.initials: DB
authors.lastname: Elias
authors.forename: Lilianne Brito da Silva
authors.initials: LB
authors.lastname: Rocha
authors.forename: Maritza Barbosa
authors.initials: MB
authors.lastname: Cavalcante
authors.forename: Alano Martins
authors.initials: AM
authors.lastname: Pedrosa
authors.forename: Izabel Cristina Bandeira
authors.initials: IC
authors.lastname: Justino
authors.forename: Romélia Pinheiro
authors.initials: RP
authors.lastname: Gonçalves