115 resultados para Leishmaniasis, Cutaneous
Resumo:
Aromatase inhibitors are increasingly used in the treatment of early and metastatic breast cancer. They can produce various skin adverse effects but are only rarely associated with cutaneous vasculitis. We report the first case of cutaneous vasculitis clearly associated with the use of aromatase inhibitor letrozole.
Resumo:
A national information program, focusing on the main recognized risk factors (primary prevention) and on the potential benefits of early detection (secondary prevention) of cutaneous malignant melanoma, was launched in Switzerland in May 1988. The first campaign, based on a pilot study conducted in 1986 in the canton of Basel, was followed by a recall campaign in July 1989. This report describes the organization of this program and presents an assessment of its initial impact. The number of newly diagnosed cases increased more than twofold (+ 116%) in the two months following the launch of the first campaign (May to June 1988). This trend was accompanied by a statistically significant shift of case distribution towards younger ages (< 60 years; p = 0.003), and a non-significant shift was observed towards less advanced lesions (thickness < or = 1.5 mm). The incidence decreased quickly, though in the twelve month period between the two campaigns it remained 21% higher than before the inception of the program. No appreciable effects were detected from the recall campaign and no difference was seen among regions or between sexes.
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The underlying mechanisms resulting in the profound immune suppression characteristic of human visceral leishmaniasis (VL) are not fully understood. Here, we tested the hypothesis that arginase, an enzyme associated with immunosuppression, is higher in patients with VL and contributes to impaired T cell responses. We recruited patients with VL before and after treatment and healthy controls and measured the arginase metabolism in the blood of these individuals. Our results show that arginase activity is significantly higher in the blood of patients with active VL as compared to controls. These high levels of arginase decline considerably once the patients are successfully treated. We identified the phenotype of arginase-expressing cells among PBMCs as neutrophils and show that their frequency was increased in PBMCs of patients before treatment; this coincides with reduced levels of L-arginine in the plasma and decreased expression levels of CD3ζ in T cells.
Resumo:
PURPOSE: To investigate the mechanism(s) of resistance to the RAF-inhibitor vemurafenib, we conducted a comprehensive analysis of the genetic alterations occurring in metastatic lesions from a patient with a BRAF(V600E)-mutant cutaneous melanoma who, after a first response, underwent subsequent rechallenge with this drug. EXPERIMENTAL DESIGN: We obtained blood and tissue samples from a patient diagnosed with a BRAF(V600E)-mutant cutaneous melanoma that was treated with vemurafenib and achieved a near-complete response. At progression, he received additional lines of chemo/immunotherapy and was successfully rechallenged with vemurafenib. Exome and RNA sequencing were conducted on a pretreatment tumor and two subcutaneous resistant metastases, one that was present at baseline and previously responded to vemurafenib (PV1) and one that occurred de novo after reintroduction of the drug (PV2). A culture established from PV1 was also analyzed. RESULTS: We identified two NRAS-activating somatic mutations, Q61R and Q61K, affecting two main subpopulations in the metastasis PV1 and a BRAF alternative splicing, involving exons 4-10, in the metastasis PV2. These alterations, known to confer resistance to RAF inhibitors, were tumor-specific, mutually exclusive, and were not detected in pretreatment tumor samples. In addition, the oncogenic PIK3CA(H1047R) mutation was detected in a subpopulation of PV1, but this mutation did not seem to play a major role in vemurafenib resistance in this metastasis. CONCLUSIONS: This work describes the coexistence within the same patient of different molecular mechanisms of resistance to vemurafenib affecting different metastatic sites. These findings have direct implications for the clinical management of BRAF-mutant melanoma. Clin Cancer Res; 19(20); 5749-57. ©2013 AACR.
Resumo:
BRAF inhibitory therapy is the mainstream treatment for BRAF mutant advanced melanoma. However vemurafenib, a type I mutant BRAF V600 inhibitor, induces an array of proliferative skin disorders from keratosis pilaris-like and keratoacanthoma-like lesions to locally aggressive cutaneous squamous cell carcinoma (cuSCC). Dual BRAF/MEK inhibition is known to lower the incidence of such manifestations, but it is not known whether it can counteract established lesions. Here we show, for the first time, a dramatic response and a restitution ad integro upon dual inhibition of a widespread proliferative affection induced by BRAF monotherapy. A 75-year-old woman was diagnosed with a BRAF V600E mutated metastatic melanoma. Following dacarbazine (DTIC) and ipilimumab, the patient was started on 960 mg twice daily vemurafenib (Zelboraf), which resulted in complete response, but the patient also developed grade IV skin toxicity. Despite dose-reduction to 720 mg twice daily the side effects persisted. We hypothesized that a switch to double inhibition of the mitogen-activated protein kinase pathway with dabrafenib and trametinib could lead to improvement of the skin lesions, while preserving tumor control. The patient was closely followed for changes in skin lesions. We witnessed a rapid regression followed by complete disappearance of all side effects of vemurafenib except for grade I fatigue. The biopsied skin lesions show regression of established keratoacanthoma-like lesions with signs of apoptosis. Switching from the current standard of care vemurafenib therapy to the double BRAF/MEK inhibition in BRAF mutant melanoma patients results in rapid disappearance of established proliferative skin disorders.
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The protozoan Leishmania mexicana parasite causes chronic non-healing cutaneous lesions in humans and mice with poor parasite control. The mechanisms preventing the development of a protective immune response against this parasite are unclear. Here we provide data demonstrating that parasite sequestration by neutrophils is responsible for disease progression in mice. Within hours of infection L. mexicana induced the local recruitment of neutrophils, which ingested parasites and formed extracellular traps without markedly impairing parasite survival. We further showed that the L. mexicana-induced recruitment of neutrophils impaired the early recruitment of dendritic cells at the site of infection as observed by intravital 2-photon microscopy and flow cytometry analysis. Indeed, infection of neutropenic Genista mice and of mice depleted of neutrophils at the onset of infection demonstrated a prominent role for neutrophils in this process. Furthermore, an increase in monocyte-derived dendritic cells was also observed in draining lymph nodes of neutropenic mice, correlating with subsequent increased frequency of IFNγ-secreting T helper cells, and better parasite control leading ultimately to complete healing of the lesion. Altogether, these findings show that L. mexicana exploits neutrophils to block the induction of a protective immune response and impairs the control of lesion development. Our data thus demonstrate an unanticipated negative role for these innate immune cells in host defense, suggesting that in certain forms of cutaneous leishmaniasis, regulating neutrophil recruitment could be a strategy to promote lesion healing.
Resumo:
Cutaneous melanoma is the most deadly cutaneous neoplasm. In order to guide treatment decisions and follow-up of melanoma patients, guidelines for the management of melanoma in Switzerland were inaugurated in 2001 and revised in 2006 and 2016. Recent data on surgical and medical treatments from randomised trials necessitated modification of the treatment and follow-up recommendations.
Resumo:
Treatment failure and symptomatic relapse are major concerns in American tegumentary leishmaniasis (TL). Such complications are seen frequently in Leishmania guyanensis infections, in which patients respond variously to first-line antileishmanials and are more prone to develop chronic cutaneous leishmaniasis. The factors underlying this pathology, however, are unknown. Recently, we reported that a double-stranded RNA virus, Leishmania RNA virus 1 (LRV1), nested within L. guyanensis parasites is able to exacerbate experimental murine leishmaniasis by inducing a hyperinflammatory response. This report investigates the prevalence of LRV1 in human L. guyanensis infection and its effect on treatment efficacy, as well as its correlation to symptomatic relapses after the completion of first-line treatment. In our cohort of 75 patients with a diagnosis of primary localized American TL, the prevalence of LRV1-positive L. guyanensis infection was elevated to 58%. All patients infected with LRV1-negative L. guyanensis were cured after 1 dose (22 of 31 [71%]) or 2 doses (31 of 31 [100%]) of pentamidine. In contrast, 12 of 44 LRV1-positive patients (27%) presented with persistent infection and symptomatic relapse that required extended therapy and the use of second-line drugs. Finally, LRV1 presence was associated with a significant increase in levels of intra-lesional inflammatory markers. In conclusion, LRV1 status in L. guyanensis infection is significantly predictive (P = .0009) of first-line treatment failure and symptomatic relapse and has the potential to guide therapeutic choices in American TL.