A Double-blind, Randomized Trial to Evaluate Miltefosine and Topical Granulocyte Macrophage Colony-stimulating Factor in the Treatment of Cutaneous Leishmaniasis Caused by Leishmania braziliensis in Brazil.

BACKGROUND: The treatment of cutaneous leishmaniasis (CL) in Brazil using pentavalent antimony (Sbv) is associated with a high rate of failure. Miltefosine has proven efficacy for CL caused by L. braziliensis, with a cure rate (CR) of 75%. A combined treatment with granulocyte macrophage colony-stimulating factor (GM-CSF) and miltefosine could increase CR and decrease healing time. METHODS: A randomized, double-blind clinical trial to evaluate the efficacy of miltefosine combined with topical GM-CSF (M + GM) vs miltefosine and placebo (M + P) vs Sbv in 133 patients with CL caused by L. braziliensis in Bahia, Brazil. RESULTS: The final CR at 180 days after the initiation of treatment was 44.4% in the Sbv group, 76.6% in the M + P group (P = .003 vs Sbv), and 75.6% in the M + GM group (P = .004 vs Sbv). The median healing time for cure was 102 days for the Sbv group and 60 days for both miltefosine groups (P = .0009). During the 6-month follow-up period, 4 relapses were documented: 1 in the Sbv group, 1 in the M + P group, and 2 in the M + GM group. Mild adverse events occurred in 65% of patients from the Sbv group, 76% and 79% from the M + P and M + GM groups respectively. CONCLUSIONS: Miltefosine is more effective than Sbv for the treatment of CL caused by L. braziliensis in Brazil and accelerates the healing time. Association with GM-CSF does not improve therapeutic outcome. CLINICAL TRIALS REGISTRATION: NCT03023111.

Early Cutaneous Leishmaniasis Patients Infected With Leishmania braziliensis Express Increased Inflammatory Responses After Antimony Therapy.

Background: Early cutaneous leishmaniasis (ECL) is characterized by a nonulcerated papular lesion and illness duration less than 30 days. Approximately 4 weeks later, the cutaneous leishmaniasis (CL) ulcers appear. We were surprised to find that failure after antimony therapy (Sb5) is higher in ECL than CL. We hypothesize that the inflammatory response in ECL patients may increase during Sb5 therapy, which leads to treatment failure. Methods: A cohort of 44 ECL patients infected by Leishmania braziliensis was established to evaluate the response to Sb5 and to compare immunologic responses in ECL patients with CL and healthy subjects. Results: A hierarchical clustering based on cytokine levels showed a weak positive correlation between proinflammatory cytokine levels and those patients that failed Sb5 treatment. Although Sb5 therapy decreased interferon-γ and tumor necrosis factor levels in CL patients, we were surprised to find that an increase in these cytokines was observed in ECL patients. Moreover, interleukin (IL)-10 was less able to down-modulate immune responses in ECL. Conclusions: The enhanced production of proinflammatory cytokines, due in part to the decreased ability of IL-10 to down-modulate immune response during therapy in ECL, promotes the development and persistence of leishmania ulcer despite antimony therapy.

Fluconazole in the Treatment of Cutaneous Leishmaniasis Caused by Leishmania braziliensis: A Randomized Controlled Trial.

BACKGROUND: The treatment of cutaneous leishmaniasis (CL) caused by Leishmania braziliensis in Brazil with pentavalent antimony (Sbv) is associated with a high rate of failure, up to 45% of cases. In addition, Sbv can only administered parenterally and has important toxic effect. An effective, safe, and oral treatment for CL is required. METHODS: A randomized controlled clinical trial was conducted to compare the efficacy and safety of high-dosage oral fluconazole (6.5-8.0 mg/kg/d for 28 days) versus a standard Sbv protocol (20 mg/kg/d for 20 days) for the treatment of CL in Bahia, Brazil. RESULTS: A total of 53 subjects were included in the trial; 26 were treated with Sbv, and 27 with fluconazole. Intention-to-treat analysis showed initial cure rates (2 months after treatment) of 22.2% (6 of 27) in the fluconazole and 53.8% (14 of 26) in the Sbv group (P = .04). Six months after treatment, the final cure rate remained the same in both groups, without any relapses. The frequencies of adverse effects in the Sbv and fluconazole groups were similar, 34.6% versus 37% respectively. One patient treated with fluconazole discontinued treatment owing to malaise, headache, and moderate dizziness (Common Terminology Criteria for Adverse Events grade 2). CONCLUSIONS: Oral fluconazole at a dosage of 6.5-8 mg/kg/d for 28 days should not be considered an effective treatment for CL caused by L. braziliensisClinical Trials Registration. NCT01953744.

Treatment of Disseminated Leishmaniasis With Liposomal Amphotericin B.

BACKGROUND: Disseminated leishmaniasis (DL) is a severe and emerging form of American tegumentary leishmaniasis, associated primarily with infection by Leishmania brasiliensis. DL is defined by the presence of ≥10 mixed-type lesions such as inflammatory papules and ulcers, located in ≥2 body parts. Most patients have hundreds of lesions all over the body, and mucosal involvement is detected in up to 44% of cases. DL is a difficult to cure disease and pentavalent antimony (Sb(v)) is used as standard treatment, its highest dosage being 20 mg/kg/day, for 30 days. However, less than 25% of DL cases will be cured after standard therapy, and the majority of cases will require more than one course of Sb(v) for a cure. In this context, new therapies are needed that offer a higher cure rate and a better safety profile, with convenience in drug administration. METHODS: We have evaluated liposomal amphotericin B in 20 patients with DL in an open clinical trial. The total dose ranged from 17 to 37 mg/kg, used in 7 to 14 days of treatment. RESULTS: Cure rate at 3 months after therapy was 70%. One relapse was documented 4 months after treatment, producing a final cure rate of 65%. Although liposomal amphotericin B was considered well tolerated, mild adverse events were documented in 75% of the patients. CONCLUSIONS: Liposomal amphotericin B is an effective therapy for DL, with a higher final cure rate of 75% observed when used in a total dose above 30 mg/kg. CLINICAL TRIALS REGISTRATION: NCT02025491.

Association between an emerging disseminated form of leishmaniasis and Leishmania (Viannia) braziliensis strain polymorphisms.

Leishmania (Viannia) braziliensis causes three main types of American tegumentary leishmaniasis (ATL), localized cutaneous leishmaniasis (CL), mucosal leishmaniasis (ML), and disseminated leishmaniasis (DL). All forms are observed among individuals of Corte de Pedra, Brazil. We previously used random amplified markers to identify a multiclonal population among L. (V.) braziliensis isolates from ATL patients, defining parasite clades associated with different clinical syndromes. Herein we compared sequences of random amplified markers to identify genotypes of L. (V.) braziliensis recovered from lesions of CL, ML, and DL patients. Six polymorphic genomic loci were sequenced from 35 parasite isolates. Single-nucleotide polymorphisms (SNPs) and insertions-deletions (indels) at each locus allowed us to segregate the L. (V.) braziliensis population according to haplotypes. Several SNPs, indels, and haplotypes were significantly associated with an increased risk of DL. Molecular genotyping may provide markers to identify L. (V.) braziliensis strains likely to cause this emerging, hard-to-treat form of ATL.

Leishmania braziliensis causing human disease in Northeast Brazil presents loci with genotypes in long-term equilibrium.

BACKGROUND: Leishmaniases are neglected tropical diseases that inflict great burden to poor areas of the globe. Intense research has aimed to identify parasite genetic signatures predictive of infection outcomes. Consistency of diagnostic tools based on these markers would greatly benefit from accurate understanding of Leishmania spp. population genetics. We explored two chromosomal loci to characterize a population of L. braziliensis causing human disease in Northeast Brazil. METHODOLOGY/PRINCIPAL FINDINGS: Two temporally distinct samples of L. braziliensis were obtained from patients attending the leishmaniasis clinic at the village of Corte de Pedra: (2008-2011) primary sample, N = 120; (1999-2001) validation sample, N = 35. Parasites were genotyped by Sanger's sequencing of two 600 base pairs loci starting at nucleotide positions 3,074 and 425,451 of chromosomes 24 and 28, respectively. Genotypes based on haplotypes of biallelic positions in each locus were tested for several population genetic parameters as well as for geographic clustering within the region. Ample geographic overlap of genotypes at the two loci was observed as indicated by non-significant Cusick and Edward's comparisons. No linkage disequilibrium was detected among combinations of haplotypes for both parasite samples. Homozygous and heterozygous genotypes displayed Hardy-Weinberg equilibrium (HWE) at both loci in the two samples when straight observed and expected counts were compared by Chi-square (p>0.5). However, Bayesian statistics using one million Monte-Carlo randomizations disclosed a less robust HWE for chromosome 24 genotypes, particularly in the primary sample (p = 0.04). Fixation indices (Fst) were consistently lower than 0.05 among individuals of the two samples at both tested loci, and no intra-populational structuralization could be detected using STRUCTURE software. CONCLUSIONS/SIGNIFICANCE: These findings suggest that L. braziliensis can maintain stable populations in foci of human leishmaniasis and are capable of robust genetic recombination possibly due to events of sexual reproduction during the parasite's lifecycle.

Serial quantitative PCR assay for detection, species discrimination, and quantification of Leishmania spp. in human samples.

The Leishmania species cause a variety of human disease syndromes. Methods for diagnosis and species differentiation are insensitive and many require invasive sampling. Although quantitative PCR (qPCR) methods are reported for leishmania detection, no systematic method to quantify parasites and determine the species in clinical specimens is established. We developed a serial qPCR strategy to identify and rapidly differentiate Leishmania species and quantify parasites in clinical or environmental specimens. SYBR green qPCR is mainly employed, with corresponding TaqMan assays for validation. The screening primers recognize kinetoplast minicircle DNA of all Leishmania species. Species identification employs further qPCR set(s) individualized for geographic regions, combining species-discriminating probes with melt curve analysis. The assay was sufficient to detect Leishmania parasites, make species determinations, and quantify Leishmania spp. in sera, cutaneous biopsy specimens, or cultured isolates from subjects from Bangladesh or Brazil with different forms of leishmaniasis. The multicopy kinetoplast DNA (kDNA) probes were the most sensitive and useful for quantification based on promastigote standard curves. To test their validity for quantification, kDNA copy numbers were compared between Leishmania species, isolates, and life stages using qPCR. Maxicircle and minicircle copy numbers differed up to 6-fold between Leishmania species, but the differences were smaller between strains of the same species. Amastigote and promastigote leishmania life stages retained similar numbers of kDNA maxi- or minicircles. Thus, serial qPCR is useful for leishmania detection and species determination and for absolute quantification when compared to a standard curve from the same Leishmania species.

Immunoregulatory and Effector Activities in Human Cutaneous and Mucosal Leishmaniasis: Understanding Mechanisms of Pathology.

Individuals infected with Leishmania braziliensis may develop the relatively benign localized cutaneous (CL) form or the mucosal (ML) form of the disease, which represents a more severe and mutilating variation. Interaction between parasite and host cells, as well as the genetic background of the host, are important determinants of the immune response, which is critical in determining disease outcome. Our studies over the years have been designed to determine the immunoregulatory and effector functions that culminate in the formation of lesions in CL and ML disease and how these host response factors may be better understood for design of novel therapies and prophylaxis. By studying the immune response from CL and ML patients in both the peripheral blood and in situ, we have learned much concerning the dynamics of the host-pathogen interaction that leads to the development of CL and ML. We used multiparameter flow cytometry to study the immunoregulatory profiles of the peripheral blood leukocytes, as well as laser scanning confocal microscopy to examine in situ several aspects of the local response, including the intensity of the inflammatory infiltrate, the cellular composition, inflammatory and anti-inflammatory cytokine expression, and the expression of the effector cytotoxic molecule, granzyme A, in lesions from CL and ML patients. Moreover, the application of correlative analysis between these immunological parameters has helped shed light on disease progression in CL and ML. These findings are reviewed within the context of understanding cellular and molecular mechanisms associated with the development of pathology in these diseases through a comparative analysis of the clinical forms, CL and ML, as well as of studies derived from peripheral blood and lesions.

Influence of Intestinal Helminth Burden on Clinical Manifestations, Therapeutic Response, and Leishmania braziliensis Load in Patients with New World Cutaneous Leishmaniasis.

Leishmania braziliensis is the most important cause of cutaneous leishmaniasis (CL) in the Americas. A Th1-type immune response is required to control Leishmania infection, but an exaggerated inflammatory response leads to the development of ulcers seen in CL. Infection with intestinal helminths has the potential to inhibit the Th1 response in a manner that depends both on the species of helminth present as well as the burden of helminthiasis. We conducted a prospective cohort study of CL patients from an endemic area between January and December 2017 with either negative or high intestinal helminth burden to characterize relationships between helminth burden, L. braziliensis quantification within CL lesions, clinical aspects of CL, and therapeutic response. Of 234 participants with leishmaniasis who underwent stool examination at the time of diagnosis, 45% had detectable helminth infection. The overall cure rate after 90 days was 66%, with a median time to resolution of disease of 40 days (interquartile range: 30-65 days). There was no significant association between the type of helminth infection or the magnitude of intestinal helminth burden at the time of diagnosis and L. braziliensis genomic DNA (gDNA) detected in biopsies from CL lesions. Likewise, there was no association between helminth burden and response to treatment after 90 days. Considering quantification of parasite DNA in CL lesions, participants who were cured at 90 days had a median of 0.017 ng/mg gDNA, and participants who failed therapy had a median of 0.091 ng/mg gDNA (P = 0.03). The results indicate that cutaneous Leishmania load may influence therapeutic response in CL.

The Influence of Infection by Different Leishmania (Viannia) braziliensis Isolates on the Pathogenesis of Disseminated Leishmaniasis.

Disseminated Leishmaniasis (DL) is an emerging and severe form of Leishmania (Viannia) braziliensis infection defined by the presence of 10 and up to more than 1,000 skin lesions. The mechanisms underlying parasite dissemination remain unknown. Genotypic differences among species of L. braziliensis have been associated with different clinical forms of disease. The present work compared the function of monocytes obtained from patients with cutaneous leishmaniasis (CL) and DL in response to infection with L. braziliensis isolates of both these two clinical forms of disease. Mononuclear cells obtained from DL and CL patients were infected with different L. braziliensis isolates, and numbers of infected cells, parasite load, respiratory burst, TLR2 and TLR4 expression and cytokine production were evaluated. DL isolates infected more monocytes, induced greater respiratory burst, and more cytokine production compared to isolates from CL patients regardless of the origin of monocytes (DL or CL). However, greater parasite multiplication and higher TLR2 and TLR4 expression were seen in monocytes from DL patients compared to CL following infection with DL isolates. Our results indicate the participation of both parasite genotype and host factors in the pathogenesis of DL.

Leishmania-Induced Dendritic Cell Migration and Its Potential Contribution to Parasite Dissemination.

Leishmania, an intracellular parasite species, causes lesions on the skin and in the mucosa and internal organs. The dissemination of infected host cells containing Leishmania is crucial to parasite survival and the establishment of infection. Migratory phenomena and the mechanisms underlying the dissemination of Leishmania-infected human dendritic cells (hDCs) remain poorly understood. The present study aimed to investigate differences among factors involved in hDC migration by comparing infection with visceral leishmaniasis (VL) induced by Leishmaniainfantum with diverse clinical forms of tegumentary leishmaniasis (TL) induced by Leishmaniabraziliensis or Leishmania amazonensis. Following the infection of hDCs by isolates obtained from patients with different clinical forms of Leishmania, the formation of adhesion complexes, actin polymerization, and CCR7 expression were evaluated. We observed increased hDC migration following infection with isolates of L. infantum (VL), as well as disseminated (DL) and diffuse (DCL) forms of cutaneous leishmaniasis (CL) caused by L. braziliensis and L. amazonensis, respectively. Increased expression of proteins involved in adhesion complex formation and actin polymerization, as well as higher CCR7 expression, were seen in hDCs infected with L. infantum, DL and DCL isolates. Together, our results suggest that hDCs play an important role in the dissemination of Leishmania parasites in the vertebrate host.

Geographic clustering of leishmaniasis in northeastern Brazil.

To determine whether disease outcomes and clades of Leishmania braziliensis genotypes are associated, we studied geographic clustering of clades and most severe disease outcomes for leishmaniasis during 1999-2003 in Corte de Pedra in northeastern Brazil. Highly significant differences were observed in distribution of mucosal leishmaniasis versus disseminated leishmaniasis (DL) (p<0.0001). Concordance was observed between distribution of these disease forms and clades of L. braziliensis genotypes shown to be associated with these disease forms. We also detected spread of DL over this region and an inverse correlation between frequency of recent DL diagnoses and distance to a previous DL case. These findings indicate that leishmaniasis outcomes are distributed differently within transmission foci and show that DL is rapidly spreading in northeastern Brazil.

Clinical and histopathologic features of canine tegumentary leishmaniasis and the molecular characterization of Leishmania braziliensis in dogs.

BACKGROUND: Cutaneous leishmaniasis (CL), caused by Leishmania braziliensis, is the most important presentation of tegumentary leishmaniasis (TL) in Latin American. While the role of dogs as reservoirs of Leishmania infantum, and the clinic features of canine visceral leishmanisis are well described, little is known about the importance of dogs in the transmission of L. braziliensis to humans. In the present study, we determine the frequency of L. braziliensis infection in dogs with cutaneous and mucosal ulcers in an endemic area of CL. We also describe the clinical manifestations and histopathologic features, and determine if the parasites isolated from dogs are genetically similar to those found in humans. METHODOLOGY: This is a cross sectional study in which 61 dogs living in an endemic area of CL and presenting ulcerated lesions were evaluated. Detection of L. braziliensis DNA by polymerase chain reaction (PCR) in skin biopsies, serology and leishmania skin test (LST) with soluble L. braziliensis antigen were performed. The clinical and histopathologic features were described, and we compared the genotypic characteristics of isolates obtained from dogs and humans. PRINCIPAL FINDINGS: The sensitivity of the three tests together to detect exposure was 89% and the concordance between the tests was high. The skin lesions were most frequent in the ears, followed by scrotal sac. The PCR was positive in 41 (67%) of animals, and the lesions in the snout, followed by the scrotal sac and ears were the sites where parasite DNA was most detected. There were genotype similarities between L.braziliensis isolates from dogs and humans. CONCLUSIONS: The high frequency of L. braziliensis infection in dogs with ulcers and the similarities between the isolates of L. braziliensis and cutaneous leishmaniasis in dogs and humans in an endemic area of TL, raise the possibility of an important role of dogs in the transmission chain of L. braziliensis.

Investigation of the pathways related to intrinsic miltefosine tolerance in Leishmania (Viannia) braziliensis clinical isolates reveals differences in drug uptake.

In Brazil, cutaneous leishmaniasis is caused predominantly by L. (V.) braziliensis. The few therapeutic drugs available exhibit several limitations, mainly related to drug toxicity and reduced efficacy in some regions. Miltefosine (MF), the only oral drug available for leishmaniasis treatment, is not widely available and has not yet been approved for human use in Brazil. Our group previously reported the existence of differential susceptibility among L. (V.) braziliensis clinical isolates. In this work, we further characterized three of these isolates of L. (V.) braziliensis chosen because they exhibited the lowest and the highest MF half maximal inhibitory concentrations and were therefore considered less tolerant or more tolerant, respectively. Uptake of MF, and also of phosphocholine, were found to be significantly different in more tolerant parasites compared to the less sensitive isolate, which raised the hypothesis of differences in the MF transport complex Miltefosine Transporter (MT)-Ros3. Although some polymorphisms in those genes were found, they did not correlate with the drug susceptibility phenotype. Drug efflux and compartmentalization were similar in the isolates tested, and amphotericin B susceptibility was retained in MF tolerant parasites, suggesting that increased fitness was also not the basis of observed differences. Transcriptomic analysis revealed that Ros3 mRNA levels were upregulated in the sensitive strain compared to the tolerant ones. Increased mRNA abundance in more tolerant isolates was validated by quantitative PCR. Our results suggest that differential gene expression of the MT transporter complex is the basis of the differential susceptibility in these unselected, naturally occurring parasites.

Recent developments leading toward a paradigm switch in the diagnostic and therapeutic approach to human leishmaniasis.

PURPOSE OF REVIEW: To identify recent papers showing how human and parasite genetics influence leishmaniasis, and how understanding of the immunopathology may be utilized in immunotherapy for these diseases. RECENT FINDINGS: Progress has been made in recent years showing the complexity within populations of Leishmania spp. and indicating that different strains lead to diverse clinical pictures and responses to treatment. Thus detection of parasite genetic tags for the precise identification of infecting strains, and for predictive diagnosis of clinical and therapeutic fates seems now possible. Host genetic loci involved in disease outcome have been detected, which may also be explored for better case management. These developments in diagnosis will demand expanding the therapeutic arsenal to take their expected effect. This is starting to be fulfilled by immunotherapies successfully employed to treat cases refractory to standard first line drugs, as the result of a more profound comprehension of the immunopathology of the leishmaniases. SUMMARY: The knowledge mounting has already helped explain why different patients present different forms of leishmaniasis and respond differently to treatment, and may be on the verge of catalyzing a major change in the already over a century old paradigm of diagnosing and managing these patients.

Early Suppression of Macrophage Gene Expression by Leishmania braziliensis.

Leishmania braziliensis is an intracellular parasite that resides mostly in macrophages. Both the parasite genome and the clinical disease manifestations show considerable polymorphism. Clinical syndromes caused by L. braziliensis include localized cutaneous (CL), mucosal (ML), and disseminated leishmaniasis (DL). Our prior studies showed that genetically distinct L. braziliensis clades associate with different clinical types. Herein, we hypothesized that: (1) L. braziliensis induces changes in macrophage gene expression that facilitates infection; (2) infection of macrophages with strains associated with CL (clade B), ML (clade C), or DL (clade A) will differentially affect host cell gene expression, reflecting their different pathogenic mechanisms; and (3) differences between the strains will be reflected by differences in macrophage gene expression after initial exposure to the parasite. Human monocyte derived macrophages were infected with L. braziliensis isolates from clades A, B, or C. Patterns of gene expression were compared using Affymetrix DNA microarrays. Many transcripts were significantly decreased by infection with all isolates. The most dramatically decreased transcripts encoded proteins involved in signaling pathways, apoptosis, or mitochondrial oxidative phosphorylation. Some transcripts encoding stress response proteins were up-regulated. Differences between L. braziliensis clades were observed in the magnitude of change, rather than the identity of transcripts. Isolates from subjects with metastatic disease (ML and DL) induced a greater magnitude of change than isolates from CL. We conclude that L. braziliensis enhances its intracellular survival by inhibiting macrophage pathways leading to microbicidal activity. Parasite strains destined for dissemination may exert a more profound suppression than less invasive L. braziliensis strains that remain near the cutaneous site of inoculation.

Molecular epidemiology and in vitro evidence suggest that Leishmania braziliensis strain helps determine antimony response among American tegumenary leishmaniasis patients.

Antimony is the first line drug for treating American tegumentary leishmaniasis (ATL) in Brazil. In this country, Leishmania braziliensis causes at least three distinct forms of disease: localized cutaneous (CL), mucosal (ML) and disseminated leishmaniasis (DL). All forms can be found in Corte de Pedra, Northeast Brazil. ML and DL respond poorly to antimony, in contrast to CL. The L. braziliensis population causing ATL in Corte de Pedra is genetically very diverse, with strains of the parasite associating with the clinical form of leishmaniasis. We tested the hypotheses that antimony refractoriness is associated with L. braziliensis genotypes, and that parasites from ML and DL present greater in vitro resistance to antimony than L. braziliensis from CL. Comparison of geographic coordinates of living sites between antimony responders and non-responders by Cusick and Edward́s test showed that refractoriness and responsiveness to the drug were similarly wide spread in the region (p>0.05). Parasites were then genotyped by sequencing a locus starting at position 425,451 on chromosome 28, which is polymorphic among L. braziliensis of Corte de Pedra. Haplotype CC- in CHR28/425,451 was associated with risk of treatment failure among CL patients (Fishers exact test, p=0.03, odds ratio=4.65). This haplotype could not be found among parasites from ML or DL. Finally, sensitivity to antimony was evaluated exposing L. braziliensis promastigotes to increasing concentrations of meglumine antimoniate in vitro. Parasites from ML and DL were more resistant to antimony at doses of 2mg/100µL and beyond than those isolated from CL (Fisher's exact test, p=0.02 and p=0.004, respectively). The intrinsically lower susceptibility of L. brazliensis from ML and DL to antimony parallels what is observed for patients' responsiveness in the field. This finding reinforces that ML and DL patients would benefit from initiating treatment with drugs currently considered as second line, like amphotericin B.

The Elderly Respond to Antimony Therapy for Cutaneous Leishmaniasis Similarly to Young Patients but Have Severe Adverse Reactions.

There is evidence that elderly patients with cutaneous leishmaniasis (CL) have more mucosal and disseminated diseases than young patients and their cells produce less antigen-induced interferon (IFN)-γ. Herein, we compared the roles of interleukin (IL)-10 and IL-15 as modulators of antigen-induced immune responses and the incidence of adverse reaction and response to therapy in young versus elderly patients with CL. Study participants included 35 senior (60-85 years) and 35 young (18-40 years) patients who had a diagnosis of CL documented by typical cutaneous lesions containing Leishmania braziliensis DNA. Elderly patients had less lymph node enlargement. Antigen-induced blood cell cytokine responses were studied in the absence or presence of IL-10 antibody or exogenously added recombinant IL-15. The ratio of IFN-γ/IL-10 was lower in elderly patients, and IFN-γ production was enhanced by either neutralization of IL-10 or exogenous recombinant IL-15 in blood cells from elderly but not young patients. Patients were treated three times weekly with antimony at 20 mg/kg/day for 20 doses. Although there was no difference in response to therapy between the two groups, two young patients needed rescue therapy with amphotericin B. Ventricular arrhythmias and ventricular overload were more frequent in elderly patients. We conclude that elderly patients have alterations in the immune response that may influence clinical manifestations, but we did not find that they had a higher failure rate than young subjects to antimony therapy. However, because of the high rate of electrocardiographic abnormalities during therapy, antimony should not be used in elderly patients with CL.

Oral Pentoxifylline Associated with Pentavalent Antimony: A Randomized Trial for Cutaneous Leishmaniasis.

AbstractCutaneous leishmaniasis (CL) by Leishmania braziliensis is associated with decreasing cure rates in Brazil. Standard treatment with pentavalent antimony (Sbv) cures only 50-60% of the cases. The immunopathogenesis of CL ulcer is associated with high interferon-γ and tumor necrosis factor (TNF) production. Pentoxifylline, a TNF inhibitor, has been successfully used in association with Sbv in mucosal and cutaneous leishmaniasis. This randomized, double-blind, and placebo-controlled trial aimed to evaluate the efficacy and safety of oral pentoxifylline plus Sbv versus placebo plus Sbv in patients with CL in Bahia, Brazil. A total of 164 patients were randomized in two groups to receive the combination or the monotherapy. Cure rate 6 months after treatment was 45% in the pentoxifylline group and 43% in the control group. There was also no difference between the groups regarding the healing time (99.7 ± 66.2 days and 98.1 ± 72.7 days, respectively). Adverse events were more common in the pentoxifylline group (37.8%), versus 23% in the placebo group. This trial shows that Sbv combined therapy with pentoxifylline is not more effective than Sbv monotherapy in the treatment of CL caused by L. braziliensis.

Dynamics of American tegumentary leishmaniasis in a highly endemic region for Leishmania (Viannia) braziliensis infection in northeast Brazil.

BACKGROUND: American Tegumentary Leishmaniasis (ATL) caused by Leishmania braziliensis is endemic in Corte de Pedra, Northeast Brazil. Most L. braziliensis infections manifest as localized cutaneous leishmaniasis (CL). Disseminated manifestations include mucosal leishmaniasis (ML), present at a low constant level for several decades, and newly emerging disseminated leishmaniasis (DL). Surprisingly, DL has recently surpassed ML in its spatial distribution. This led us to hypothesize that distinct forms of ATL might spread in different patterns through affected regions. METHODOLOGY/PRINCIPAL FINDINGS: We explored the incidence and geographic dispersion of the three clinical types of ATL over a span of nearly two decades in Corte de Pedra. We obtained the geographic coordinates of the homes of patients with ATL during 1992-1996, 1999-2003 and 2008-2011. The progressive dispersion of ML or DL in each time period was compared to that of CL in 2008-2011 with the Cusick and Edward's geostatistical test. To evaluate whether ATL occurred as clusters, we compared each new case in 2008-2011 with the frequency of and distance from cases in the previous 3 to 12 months. The study revealed that DL, ML and CL actively spread within that region, but in distinct patterns. Whereas CL and DL propagated in clusters, ML occurred as sporadic cases. DL had a wider distribution than ML until 2003, but by 2011 both forms were distributed equally in Corte de Pedra. The incidence of ML fluctuated over time at a rate that was distinct from those of CL and DL. CONCLUSIONS/SIGNIFICANCE: These findings suggest that CL and DL maintain endemic levels through successive outbreaks of cases. The sporadic pattern of ML cases may reflect the long and variable latency before infected patients develop clinically detectable mucosal involvement. Intimate knowledge of the geographic distribution of leishmaniasis and how it propagates within foci of active transmission may guide approaches to disease control.