L. (viannia) braziliensis infection causes American Tegumentary Leishmaniasis (ATL), with prolonged time to healing lesions. The potent inflammatory response developed by the host is important to control the parasite burden and infection however an unbalanced immunity may cooperate to the tissue damage observed. The range of mechanisms underlying the pathological responses associated with ATL still needs to be better understood. That includes epigenetic regulation by non-coding MicroRNAs (miRNAs), non-coding sequences around 22 nucleotides that act as post-transcriptional regulators of RNAs encoding proteins. The miRNAs have been associated with diverse parasitic diseases, including leishmaniasis. Here we evaluated miRNAs that targeted genes expressed in cutaneous leishmaniasis lesions (CL) by comparing its expression in both CL and normal skin obtained from the same individual. In addition, we evaluated if the miRNAs expression would be correlated with clinical parameters such as therapeutic failure, healing time as well as lesion size. The miR-361-3p and miR-140-3p were significantly more expressed in CL lesions compared to normal skin samples (p = 0.0001 and p < 0.0001, respectively). In addition, the miR-361-3p was correlated with both, therapeutic failure and healing time of disease (r = 0.6, p = 0.003 and r = 0.5, p = 0.007, respectively). In addition, complementary analysis shown that miR-361-3p is able to identify with good sensitivity (81.2%) and specificity (100%) patients who tend to fail initial treatment with pentavalent antimonial (Sbv). Finally, the survival analysis considering “cure” as the endpoint showed that the higher the expression of miR-361-3p, the longer the healing time of CL. Overall, our data suggest the potential of miR-361-3p as a prognostic biomarker in CL caused by L. braziliensis.

Background The treatment of cutaneous leishmaniasis (CL) in Brazil by pentavalent antimony (Sb v) is associated with a high rate of failure. Oral miltefosine in monotherapy has proven high efficacy in CL caused by L. braziliensis with a cure rate of 75%. A combined treatment with GM-CSF and miltefosine was tested to increase the cure rate and decrease the healing time Methods This is a randomized and double-blind clinical trial to evaluate the efficacy of miltefosine combined with topical GM-CSF (M+GM) versus miltefosine and placebo (M+P) versus standard Sb v in the treatment of 133 patients with CL caused by L. braziliensis in Bahia, Brazil Results The final cure rate at 180 days after the initiation of treatment was 44.4% in the Sb v group, 76.6% in the M+P group (P= 0.003 versus Sb v), and 75.6% in the M+GM group (P= 0.004 versus Sb v). By survival curve analysis median healing time for cure was 102 for Sb v group and 60 days for both miltefosine groups (P= 0.0009). During the 6 months follow-up period, four relapses were documented, one in the Sb v group (2%), one in the M+P group (2%) and two in the M+GM group (5%). Adverse events were documented in 65% of subjects from Sb v group, 79% of M+GM group and 76% of M+P group Conclusions Miltefosine is more effective than standard Sb v for the treatment of CL caused by L. braziliensis in Brazil and accelerate the healing time of CL. The association of Miltefosine with GM-CSF do not improve therapeutic outcome

Background Our goal was to identify genetic risk factors for cutaneous leishmaniasis (CL) caused by Leishmania braziliensis. Methods Genotyping 2066 CL cases and 2046 controls using Illumina HumanCoreExomeBeadChips provided data for 4,498,586 imputed single nucleotide variants (SNVs). Genome-wide association testing using linear mixed models took account of genetic diversity/ethnicity/admixture. Post-GWAS positional, expression quantitative trait locus (eQTL), and chromatin interaction mapping was performed in FUMA. Transcriptional data were compared between lesions and normal skin, and cytokines measured using flow cytometry and Bioplex assay. Results Positional mapping identified 32 genomic loci associated with CL, none achieving genome-wide significance (P&5x10 -8). Lead SNVs at 23 loci occurred at protein coding or non-coding RNA genes, 15 with eQTLs for functionally relevant cells/tissues and/or showed differential expression in lesions. Of these, the 6 most plausible genetic risk loci were: SERPINB10 (Pimputed_1000G=2.67x10 -6), CRLF3 (Pimputed_1000G=5.12x10 -6), STX7 (Pimputed_1000G=6.06x10 -6), KRT80 (Pimputed_1000G=6.58x10 -6), LAMP3 (Pimputed_1000G=6.54x10 -6) and IFNG-AS1 (Pimputed_1000G=1.32x10 -5). LAMP3 (Padjusted=9.25x10 -12; +6-fold), STX7 (Padjusted=7.62x10 -3; +1.3-fold) and CRLF3 (Padjusted=9.19x10 -9; +1.97-fold) were expressed more highly in CL biopsies compared to normal skin; KRT80 (Padjusted=3.07x10 -8; -3-fold) was lower. Multiple cis-eQTLs across SERPINB10 mapped to chromatin interaction regions of transcriptional/enhancer activity in neutrophils, monocytes, B cells and haematopoietic stem cells. Those at IFNG-AS1 mapped to transcriptional/enhancer regions in T, natural killer, and B cells. The percent peripheral blood CD3 + T cells making antigen-specific interferon-γ differed significantly by IFNG-AS1 genotype. Conclusions This first GWAS for CL identified multiple genetic risk loci including a novel lead to understanding CL pathogenesis through regulation of interferon-γ by IFNG antisense RNA 1.