Avaliação do papel do TREM-1 solúvel na apresentação e complicações clínicas da hanseníase

Abstract

Leprosy is a chronic, slowly evolving infectious disease caused by Mycobacterium leprae (M. leprae). It’s an important public health problem in Brazil and in the world, especially regarding to the epidemiology and the physical disability, creating a social stigma for the patients. The literature suggests that less than 1% of bacillus-infected individuals develop with the disease and that the susceptibility or resistance to the disease depends on genetic factors and the patient's immune response. When there is a mismatch of the immune response and it becomes extremely intense and uncontrolled, leprosy reactions (LR) occurs. LR is the focus of possible nervous involvement, or aggravation of already affected areas that contribute directly to the appearance of physical disability. The receptor activator expressed in myeloid-1 cells (TREM-1) is a cell surface receptor, expressed mainly in neutrophils and monocytes, involved in the amplification of the inflammatory response and being related to the severity and prognosis of inflammatory diseases. Considering the potential effects of TREM-1 on inflammatory reactions and intracellular infection, the aim of this study was to evaluate the role of TREM-1 in the presentation and clinical complications of leprosy. We included 76 individuals: 23 Paucibacillary (PB), 28 Multibacillary (MB) and 25 household contacts (HHC). The patients were attended at the dermatology clinic of the University Hospital of the Federal University of Sergipe (Aracaju, Brazil). The whole blood was collected in tubes with heparin (10 IU/ l) and centrifuged for collection of serum. Serum samples were stored in a freezer at -80°C. Soluble TREM-1(sTREM-1) serum levels were measured by enzyme-linked immunosorbent assay (ELISA). It was observed that MB patients had higher sTREM-1 levels when compared to PB and HHC (p<0.05). Higher levels of sTREM-1 have also been observed in Lepromatous Leprosy (LL) clinical form and in patients with physical disability and those with reactional episodes. Our results reported, for the first time, that high levels of sTREM-1 are associated with the LL form and, mainly, in LR and neurological disability. Therefore, this molecule can be an important biomarker for the monitoring of LR and physical disability in leprosy infection.