RESUMO
Os acidentes com aranhas do gênero Loxosceles podem apresentar variadas evoluções clínicas, dificultando a realização do diagnóstico e a escolha correta de uma medida terapêutica. Este artigo de revisão tem como objetivo abordar os mais importantes mecanismos de evolução, principais desfechos e os tratamentos de escolha para o acidente loxoscélico (AU)
Accidents with Loxosceles genus spiders may have different clinical outcomes, hindering the diagnosis and the correct choice of a therapeutic measure. This review article aims to address the main mechanisms of evolution, main outcomes and treatments of choice for loxoscelic accident (AU)
Assuntos
Humanos , Animais , Picada de Aranha/diagnóstico , Picada de Aranha/terapia , Aranha Marrom Reclusa/patogenicidade , Picada de Aranha/complicações , Picada de Aranha/fisiopatologia , Picada de Aranha/patologia , Picada de Aranha/prevenção & controle , Picada de Aranha/epidemiologia , Aranha Marrom Reclusa/enzimologiaRESUMO
BACKGROUND: Loxoscelism is the envenomation caused by the bite of Loxosceles spp. spiders. It entails severe necrotizing skin lesions, sometimes accompanied by systemic reactions and even death. There are no diagnostic means and treatment is mostly palliative. The main toxin, found in several isoforms in the venom, is sphingomyelinase D (SMD), a phospholipase that has been used to generate antibodies intended for medical applications. Nucleic acid aptamers are a promising alternative to antibodies. Aptamers may be isolated from a combinatorial mixture of oligonucleotides by iterative selection of those that bind to the target. In this work, two Loxosceles laeta SMD isoforms, Ll1 and Ll2, were produced in bacteria and used as targets with the aim of identifying RNA aptamers that inhibit sphingomyelinase activity. RESULTS: Six RNA aptamers capable of eliciting partial but statistically significant inhibitions of the sphingomyelinase activity of recombinant SMD-Ll1 and SMD-Ll2 were obtained: four aptamers exert ~17% inhibition of SMD-Ll1, while two aptamers result in ~25% inhibition of SMD-Ll2 and ~18% cross inhibition of SMD-Ll1. CONCLUSIONS: This work is the first attempt to obtain aptamers with therapeutic and diagnostic potential for loxoscelism and provides an initial platform to undertake the development of novel anti Loxoscelesvenom agents.