Cytokine expression in the modulation of cutaneous leishmaniasis and its interaction with clinical, epidemiological and laboratory findings

Abstract

Leishmaniases are a group of zoonosis caused by protozoa of Leishmania genus with great complexity in biological characteristics. Leishmaniases constitute a serious health public problem worldwide and are widely distributed in all regions of Brazil. In the last years, the cutaneous infection was considered one of most dermatological syndromes diagnosed in travelers that going to endemic areas. The traditional diagnosis of the American cutaneous leishmaniasis (ACL) includes the microscopic examination, determination of the parasite genetic material in biopsy samples. However, as some patients with LTA have a small number of parasites in the lesions, the correct diagnosis is difficult to establish. The evolution of LTA also depends on the host response from the site of the vector bite, location of the lesions and clinical outcome. The cutaneous infection is more usual, which is characterized by a single or few skin ulcers. Around 3% of patients develop the mucosal form, which is characterized by disfiguring lesions, preferably in nasal or oro-pharyngeal mucosa. The host cellular immune response determines the course of the disease. Therefore studies evaluating the disease prognosis could signalize the physician as different therapeutic approaches, avoiding disfigurements that often cause many psychological problems in the affected population. We intend to know whether infected patients are able to express genes for the production of cytokines related to Th1, Th2 or Th17 responses. For the study of gene expression of cytokines (IFN-³, IL-12, IL-4, IL-6, TGF-², IL-27 and IL-17) will be necessary to standardize the RNA extractions, and to evaluate the purity and integrity of the molecules. In parallel we will select candidates for endogenous genes for use in as normalizers in real-time PCR. The candidates for endogenous genes will be: GAPDH gene (glyceraldehyde-3-phosphate dehydrogenase), 18S (ribosomal RNA subunit), B2M (Beta-2 microglobulin), MT-ATP (mitochondrial ATP) UBC (Ubiquitin C) and TBP (TATA Box Binding Protein). These approaches will be investigated in biopsy samples from 50 patients. The results will generate data for a better understanding of the cellular response in patients with ACL.