Polimorfismo Thr399ile de TLR4 em pacientes com aspergilose invasiva e controles

Abstract

Aspergillus sp. are fungi that are widespread in the environment and are present in soil, air, animal systems, freshwater and marine habitats and that can also grow on plants and on decomposition of organic matter. These fungi cause a wide variety of respiratory disorders and invasive aspergillosis (AI) is a very prevalent fungal infection in immunocompromised individuals. Studies show that Toll-like 4 (TLR4) gene polymorphisms may influence the innate immune response signaling pathways, increasing the susceptibility of individuals to develop AI. The aim of this study was to compare the frequency of the Thr399Ile rs4986791 TLR4 gene polymorphism in immunocompromised individuals and normal controls. A group of 22 immunocompromised individuals undergoing hematopoietic stem cell transplantation at the Araújo Jorge Hospital Transplant Service was included in the case group. The control group consisted of 100 individuals with no history of immunological impairment, assisted at the Health Laboratory PUC Goiás. After evaluation of the patient’s clinical data, whole blood sample was collected to evaluate genetic polymorphisms by using polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis. Individuals of both sexes were investigated, aged between three and 74 years, residing in the Midwest region of Brazil. Thr399Ile (rs4986791) polymorphism was investigated in the case and control group. In the group of patients with invasive aspergillosis, the wild type allele (C) was detected in 21 cases (95.5%), while the mutant allele (T) was found in only one case (4,5%). In the control group, the wild type allele (C) was detected in 93 individuals (93.0%), while the mutant allele (T) was found in seven individuals (7,0%). Significant differences in the allelic frequencies were not detected between cases and controls. Our results didn’t demonstrate a significant association between Thr399Ile polymorphism (rs4986791) and the diagnosis of invasive aspergillosis in immunosuppressed individuals. Further studies involving a larger number of participants are needed to elucidate this association. POLIMORFISMO Thr399Ile DE TLR4 EM PACIENTES COM ASPERGILOSE INVASIVA E CONTROLES