Investigação do polimorfismo do exon - 1 do gene MBL (Mannose-Binding Lectin) em pacientes portadores de tuberculose

Abstract

Mannose-binding lectin (MBL) is considered an acute phase protein with important role in the first line of defense of the innate immune system, whose serum levels are genetically determined. The MBL activates the lectin pathway of complement, and mediate the phagocytosis of microorganisms and opsonization. Several studies have associated serum levels of MBL to susceptibility or resistance to infectious agents including the Mycobacterium tuberculosis, causative agent of human tuberculosis. Aiming to evaluate the occurrence of a possible association between MBL gene polymorphisms and tuberculosis, it was evaluated the frequencies of mutations in exon 1 of MBL gene in a group of 167 TB patients, divided into 3 groups: patients with pulmonary tuberculosis, with extrapulmonary tuberculosis, patients with multiresistant tuberculosis to drugs and the control group with 159 health professionals. The identification of alleles MBL*A, *B, *C and *D was performed by polymerase chain reaction, using specific sequences of primers and subsequent enzymatic digestion. The analysis of allelic and genotypic frequencies of exon 1 did not show any significant difference between patients with tuberculosis and control group (p> 0.05). There were no significant associations between groups of pulmonary tuberculosis, extrapulmonary tuberculosis and multidrug drug among themselves and when connected to the control group. Data from our study showed no evidence of any influence of variations in the exon 1 of MBL gene in active tuberculosis, suggesting that the gene polymorphism has no influence on susceptibility to tuberculosis.