Polimorfismos dos genes MBL2, IL-10 e TNFα em pacientes com leucemia aguda na infância

Abstract

The chemotherapy used in the treatment of acute leukemias (AL) in pediatric immune system, promoting the morbidity and mortality from infection during the induction phase of treatment, the first 50 days. However, questions remain about why some of these children develop severe and fatal infections. The occurrence of polymorphisms (SNPs) in regions associated with regulation of immune system components may be associated with proteins that indicate the recognition of pathogens, such as the mannose-binding lectin (MBL) and cytokine tumor necrosis factor alpha (TNFα) and interleukin 10 (IL-10). The aim of this study was to evaluate the association between susceptibility to infection of pediatric patients and the following polymorphisms: -550 promoter regions (alleles H / L), -221 (alleles X / Y) and structural exon 1 (alleles A / O) MBL2 gene, the promoter region -1082 (allele G / A), -819/-592 (allele C / T) of the IL-10 gene region and -308 (allele G / A) gene TNFα. The 225 patients were evaluated in the CEONHPE / HUOC-UPE. Of these, 84% (n = 189) were diagnosed with acute lymphoblastic leukemia (ALL). Overall group (AL), there was no association between the three polymorphic regions studied with febrile neutropenia (-550 H/L, p=0.912; -221 X/Y, p=0.471; exon 1 A/O, p=0.138), number of infectious events (-550 H/L, p=0.912; exon 1 A/O, p=0.741) and the risk of relapse (-550 H/L, p=0.588; exon 1 A/O, p=0.882). However, an association was observed between age and genotype AO of exon 1 in patients younger than 10 years in AL (p=0.027) and ALL (p=0.038). In conclusion, we can suggest that the pediatric patients younger than 10 years, carriers of the MBL2 genotype AO, that determine low oligomerization and compromised biological function of the protein may have immune response deficiency.