Effect of hydroxyurea on G gamma chain fetal hemoglobin synthesis by sickle-cell disease patients

Abstract

Hydroxyurea is used for sickle-cell disease patients in order to increase fetal hemoglobin synthesis and consequently decrease the severity of pain episodes. Fetal hemoglobin, which is formed by γ-globin chains A and G, is present in a constant composition throughout fetal development: about 75% of G γ and 25% of A γ. In contrast, adult red cells contain about 40% of G γ and 60% of A γ. In the present study, we analyzed the effect of hydroxyurea induction on the γ chain composition of fetal hemoglobin in 31 sickle-cell disease patients treated with hydroxyurea. The control group was composed of 30 sickle-cell disease patients not treated with hydroxyurea in clinical steady state. The patients were older than 13 years and were not matched for age. All patients were seen at

Cis- and Trans-Acting Expression Quantitative Trait Loci Differentially Regulate Gamma-Globin Gene Expression

“…HbF is the major modulator of the severity of both sickle cell anemia and b thalassemia and considerable effort is being made to develop methods to increase HBG expression for therapeutic purposes (Deng et al 2014;Lettre and Bauer 2016). Although clinical observations suggest that an increase of HBG2 alone has some benefit (Ballas et al 1991;Teixeira et al 2003;Alsultan et al 2014), modification of trans-acting elements that affect both HbF genes might have a greater effect on HbF levels and help force a more pancellular distribution that could be therapeutically important (Sankaran et al 2011;Steinberg et al 2014;Guda et al 2015;Masuda et al 2016).…”

Manifestações retinianas em pacientes portadores de anemia de células falciformes

“…Isto ocorre através da sua ação direta sobre os precursores eritróides, reprogramando-os para uma maior produção desse tipo de hemoglobina (14) . O ácido fólico, por sua vez, segundo Teixeira et al (15) tem como objetivo tornar-se substrato para a produção da série vermelha, a qual se encontra aumentada em decorrência da anemia hemolítica, não tendo, portanto, sua ação, interferência quanto à ocorrência de oclusão vascular periférica.…”