Search results for " Leishmania"

Evaluation of Immunofluorescence Antibody Test Used for the Diagnosis of Canine Leishmaniasis in the Mediterranean Basin: A Systematic Review and Met…

2015

With an expected sensitivity (Se) of 96% and specificity (Sp) of 98%, the immunofluorescence antibody test (IFAT) is frequently used as a reference test to validate new diagnostic methods and estimate the canine leihmaniasis (CanL) true prevalence in the Mediterranean basin. To review the diagnostic accuracy of IFAT to diagnose CanL in this area with reference to its Se and Sp and elucidate the potential causes of their variations, a systematic review was conducted (31 studies for the 26-year period). Three IFAT validation methods stood out: the classical contingency table method, methods based on statistical models and those based on experimental studies. A variation in the IFAT Se and Sp …

2016

Immunologically, active visceral leishmaniasis (VL) is characterised by profound immunosuppression, severe systemic inflammatory responses and an impaired capacity to control parasite replication. Neutrophils are highly versatile cells, which play a crucial role in the induction as well as the resolution of inflammation, the control of pathogen replication and the regulation of immune responses. Neutrophil functions have been investigated in human cutaneous leishmaniasis, however, their role in human visceral leishmaniasis is poorly understood. In the present study we evaluated the activation status and effector functions of neutrophils in patients with active VL and after successful anti-l…

2016

One of the key immunological characteristics of active visceral leishmaniasis (VL) is a profound immunosuppression and impaired production of Interferon-γ (IFN-γ). However, recent studies from Bihar in India showed using a whole blood assay, that whole blood cells have maintained the capacity to produce IFN-γ. Here we tested the hypothesis that a population of low-density granulocytes (LDG) might contribute to T cell responses hyporesponsiveness via the release of arginase. Our results show that this population is affected by the anticoagulant used to collect blood: the frequency of LDGs is significantly lower when the blood is collected with heparin as compared to EDTA; however, the antico…

Insufficient generation of Th17 cells in IL-23p19-deficient BALB/c mice protects against progressive cutaneous leishmaniasis

2017

Healing of leishmaniasis-a parasitic skin disease-is associated with high levels of secreted interferon (IFN)γ and IL-12 in resistant C57BL/6 mice and humans. Susceptible BALB/c mice predominantly react with a Th17/Th2/Treg-related immune response and finally succumb to infection. Previously, we showed that BALB/c IL-17A-/- mice are protected against Leishmania (L.) major infections, indicating that IL-17A-predominantly produced by Th17 cells-plays an important role for disease outcome. We now investigated DC-derived cytokines and finally identified IL-23p19 as key cytokine responsible for induction of Leishmania-specific Th17 cells that play an important role for progressive disease in sus…

Disease control in cutaneous leishmaniasis is independent of IL-22.

2014

An agent-based model of a cutaneous leishmaniasis reservoir host, Meriones shawi

2021

International audience; Meriones shawi (M.shawi) is the main reservoir host for zoonotic cutaneous leishmaniasis (ZCL) in Central Tunisia. The incorporation of environmental and climatic effects on the spread of ZCL in M. shawi remains difficult. This study presents an agent-based model (ABM) to overcome these difficulties and examine the impact of environment (i.e. vegetation cover) and climate (i.e. temperature) on M. shawi movement and prevalence. The model simulation considers two agent types: rodent agent and field unit agent. We tested the model according to two types of rodent movement: random and thoughtful. We integrated time dependent normalized difference vegetation index (NDVI) …

Impaired T-cell-dependent protection againstLeishmania majorinfection in HIV-positive patients is associated with worsened disease outcome

2015

Cutaneous leishmaniasis (CL) patients coinfected with HIV are known to show a more severe, prolonged course of disease; the immunological basis is not known. We now assessed clinical features, sera and skin biopsies of HIV(+) and HIV(-) patients with CL to identify drivers of increased susceptibility to Leishmania. CL lesion numbers, surface, and healing duration were significantly increased in HIV(+) as compared to HIV(-) patients (2.5, 14 and4-fold, respectively). Patients with HIV infection exhibited lower serum Leishmania-specific IgG levels and decreased IL-6 and IL-8. Most importantly, dramatically decreased numbers of CD4(+) T cells (approximately eightfold), but not CD8(+) cells, to…

Evaluation of serum levels of soluble CD4, CD8 and β2-microglobulin in visceral human leishmaniasis

1994

SUMMARY The levels of soluble CD4 (sCD4), sCD8 and β2-microglobulin (β2-M) were measured in sera from patients with visceral leishmaniasis during the course of infection. Levels of sCD4. sCD8 and β2-M were raised significantly above levels In normal sera and returned to the normal range after recovery. The decrease in the levels of CDS was related to a reduction of anaemia, leukopenia and thrombocytopenia. In contrast, sCD4 levels fluctuated during the period of infection. β2-M returned within normal range more rapidly than sCD8 secretion. Our results suggest that T cells are activated during infection, and that it is also possible that the raised levels of these soluble molecules play a ro…

Unusual clinical variants of cutaneous leishmaniasis in Sicily

2009

Background  The term “leishmaniasis” defines a group of vector-borne diseases caused by species of the genus Leishmania and characterized by a spectrum of clinical manifestations. Parasite properties (infectivity, pathogenicity, virulence), host factors, and host responses regulate heterogeneous disease expression. Sicily is one of the major islands of the Mediterranean Basin and is considered to be a hypo-endemic area for cutaneous leishmaniasis. Leishmania infantum is the most common species on the island. Methods  Fifty patients (both sexes and different ages) with lesions clinically suggestive of cutaneous leishmaniasis were recorded over a 1-year period. The diagnosis was based on posi…

Asymptomatic Leishmania infantum/chagasi infection in blood donors of western Sicily.

2007

The purpose of this study was to evaluate whether the risk of transfusion-transmitted visceral leishmaniasis was present in an area of western Sicily where the incidence of the disease is higher than the regional average. From May to December 2005, 1449 blood donors from Agrigento district (Sicily, Italy) were screened for the presence of anti-Leishmania antibodies by an indirect immunofluorescent antibody test (IFAT). Blood samples from IFAT-positive donors were examined by PCR to detect Leishmania DNA. Anti-Leishmania antibodies were found in 11 (0.75%) cases, among which Leishmania DNA was detected from four (36.4%). Particular techniques to inactivate different pathogens would be consid…