Família gênica A2 como marcador de virulência viscerotrópica em protozoários do gênero Leishmania spp.: O estado da arte

Abstract

The different species of Leishmania are commonly associated with clinical conditions that include cutaneous, mucocutaneous and visceral symptoms; in some cases, apparently sporadic, species that cause cutaneous conditions cause visceral conditions and vice versa. The exact mechanism that leads to this variation in tropism within the same species of parasite is still uncertain; however, several studies have been carried out in an attempt to elucidate this behavior. The objective of the present work was to verify the state of the art of studies carried out with the A2 gene family as a viscerotropic virulence marker through a systematic literature review. A systematic review was carried out using the databases <Scopus=, <Scielo=, <Web of Science= and <Pubmed= with the following keywords: ((leishmania) AND ("a2 gene" OR "A2 protein" OR "A2rel" OR "A2 antigen" OR "A2 expression")). The <Mendeley= reference manager was used during the screening by title, abstract and full work. From the articles coming from the curated database, work identification data, information regarding markers, techniques and Leishmania species evaluated were extracted, which were stored in an Excel spreadsheet. It is concluded that although A2 is strongly involved in the visceralization capacity on Leishmania, proven even in isolates that cause atypical clinical conditions, it is not solely responsible for the tropism and virulence of the parasite. The presence of single nucleotide polymorphisms, pseudogenes and genetic duplication are the most important forms of variability in the tropism of parasites of the genus Leishmania.