Single nucleotide polymorphisms in genes involved in immune responses and outcome of tegumentary leishmaniasis

Leishmaniases are neglected tropical diseases with a broad clinical spectrum. Tegumentary leishmaniasis (TL) is a disease caused by different Leishmania species, transmitted by phlebotomine sand flies and distributed worldwide. TL can present a cutaneous (CL) or mucocutaneous (MCL) clinical form depending on factors inherent to the parasite, the host and the vector. Polymorphisms in the immune response genes are host genetic factors that influence the pathogenesis or control of leishmaniasis. Single nucleotide polymorphisms (SNPs) in immune genes have been evaluated in several countries where leishmaniasis is endemic. In this review, we report studies on SNPs in several immune genes that might be associated with susceptibility or resistance to TL. We summarize studies from around the world and in Brazil, highlight the difficulties of these studies and future analyses needed to enhance our knowledge regarding host genetic factors in TL. Understanding the genetic characteristics of the host that facilitate resistance or susceptibility to leishmaniasis can contribute to the development of immunotherapy schedules for this disease. The current treatment methods are toxic, and no human vaccine is available.