ABSTRACT
Canine leishmaniasis (CanL) caused by Leishmania infantum commonly progresses with renal and ophthalmic lesions associated with active systemic disease. As chronic inflammation related to immune complex deposits is a pathophysiological factor in the development of both glomerulonephritis and uveitis, we aimed to evaluate renal and ocular histopathological lesions and analyze whether they were related to each other and the clinical degree of the disease. For that, we evaluated 15 dogs from CanL-endemic areas. L. infantum PCR-positive dogs were studied according to disease severity into two different groups: Group-1 (G1) had data from seven dogs with mild to moderate CanL and no history of treatment, and G2 was formed with eight dogs with severe to terminal disease that had not responded to CanL treatment. Histopathological analysis of kidneys showed higher frequencies and intensities of glomerular basement membrane thickening (p = 0.026), deposits in glomeruli (p = 0.016), epithelial necrosis (p = 0.020), tubular dilatation (p = 0.003) and interstitial fibrosis (p = 0.04) in G2 dogs than in G1 dogs. Surprisingly, the histopathology of eye bulbs showed a higher frequency and intensity of retinitis (p = 0.019) in G1 dogs than in G2 dogs. The comparative analysis showed that there was no correspondence between histopathological findings in kidneys versus eyes in milder or more severe CanL. Our findings suggested that (1) clinically undetectable eye alterations can be more precocious than those in kidneys in the development of CanL, and (2) the lower frequency of eye lesions and higher frequency of renal lesions in dogs with terminal disease even after treatment indicate that therapy may have been effective in reducing CanL-associated ophthalmic disease but not proportionally in reducing kidney disease.
Subject(s)
Dog Diseases , Kidney , Leishmania infantum , Leishmaniasis, Visceral , Animals , Dogs , Dog Diseases/pathology , Dog Diseases/parasitology , Male , Kidney/pathology , Kidney/parasitology , Leishmaniasis, Visceral/veterinary , Leishmaniasis, Visceral/pathology , Leishmaniasis, Visceral/parasitology , Female , Eye/pathology , Eye/parasitologyABSTRACT
Canine leishmaniosis is a vector-borne disease caused by Leishmania infantum, and clinical manifestations of infection range from absent or severe to fatal and result from immune-mediated mechanisms. In dogs, the most common clinical signs of leishmaniosis include skin lesions and lymphadenomegaly. However, the presence of other nontypical signs has been described, and diagnosing these cases can be challenging. The aim of the present short communication was to describe the impact of the formation of circulating immunocomplexes due to L. infantum in a dog with leishmaniosis affected by a massive venous thrombus of the caudal vena cava and external iliac veins. On admission, the dog presented bilateral cutaneous vasculopathy of the thigh and renal disease due to L. infantum infection. Two weeks after starting anti-Leishmania treatment based on meglumine antimoniate and allopurinol administration, the animal developed acute claudication of the hind limbs with the presence of a thrombus in the caudal vena cava and the external iliac veins and a high level of circulating immunocomplexes detected by enzyme-linked immunosorbent assay. Exacerbation of the humoral immune response, along with deposition of circulating immune complexes in the tissues and the concurrent presence of kidney and liver damage, might have contributed to an imbalance in haemostasis in this patient. Future studies should evaluate and analyse the pathological mechanisms contributing to thrombosis in dogs with leishmaniosis.
Subject(s)
Dog Diseases , Leishmania infantum , Leishmaniasis, Visceral , Animals , Dogs , Dog Diseases/parasitology , Leishmaniasis, Visceral/veterinary , Leishmaniasis, Visceral/complications , Leishmaniasis, Visceral/pathology , Leishmaniasis, Visceral/parasitology , Male , Meglumine Antimoniate/therapeutic use , Allopurinol/therapeutic use , Antiprotozoal Agents/therapeutic use , FemaleABSTRACT
Post kala-azar dermal leishmaniasis (PKDL), a sequel of apparently cured visceral leishmaniasis (VL) presents with papulonodular (polymorphic) or hypopigmented lesions (macular) and is the proposed disease reservoir. As hypopigmentation appears consistently in PKDL, especially the macular form, this study aimed to delineate immune factors that singly or in combination could contribute towards this hypopigmentation. At lesional sites, the presence of melanocytes and CD8+ T-cells was assessed by immunohistochemistry and mRNA expression of melanogenic markers (tyrosinase, tyrosinase-related protein-1 and MITF) by droplet digital PCR, while plasma levels of cytokines and chemokines were measured by a multiplex assay. In comparison with skin from healthy individuals, macular PKDL demonstrated a near total absence of Melan-A+ cells at dermal sites, while the polymorphic cases demonstrated a 3.2-fold decrease, along with a dramatic reduction in the expression of key enzymes related to the melanogenesis signalling pathway in both forms. The levels of circulating IFN-γ, IL-6, IL-2, IL-1ß, TNF-α and IFN-γ-inducible chemokines (CXCL9/10/11) were elevated and was accompanied by an increased lesional infiltration of CD8+ T-cells. The proportion of CD8+ T-cells correlated strongly with plasma levels of IFN-γ (r = 0.8), IL-6 (r = 0.9, p < 0.05), IL-2 (r = 0.7), TNF-α (r = 0.9, p < 0.05) and IL-1ß (r = 0.7), as also with CXCL9 (r = 0.5) and CXCL10 (r = 0.6). Taken together, the absence/reduction in Melan-A suggested hypopigmentation in PKDL was associated with the destruction of melanocytes, following the impairment of the melanogenesis pathway. Furthermore, the presence of CD8+ T-cells and an enhanced IFN-γ-associated immune milieu suggested the generation of a pro-inflammatory landscape that facilitated melanocyte dysfunction/destruction.
Subject(s)
Hypopigmentation , Leishmania donovani , Leishmaniasis, Cutaneous , Leishmaniasis, Visceral , Humans , Leishmaniasis, Visceral/complications , Leishmaniasis, Visceral/pathology , MART-1 Antigen , CD8-Positive T-Lymphocytes , Interleukin-6 , Tumor Necrosis Factor-alpha , Interleukin-2ABSTRACT
Structural changes in the spleen have been reported in several infectious diseases. In visceral leishmaniasis (VL), a severe parasitic disease caused by Leishmania spp., the loss of white pulp accompanies a severe clinical presentation. Hamster model reproduces aspects of human VL progression. In the early stages, a transcriptomic signature of leukocyte recruitment was associated with white pulp hyperplasia. Subsequently, impaired leukocyte chemotaxis with loss of T lymphocytes in the periarteriolar lymphoid sheath occurred. This differential gene expression was subsequently corroborated by transcriptomic profiling of spleens in severe human VL. At the latest stage, spleen disorganization was associated with increasing clinical signs of VL. White pulp disruption was accompanied by decreased DLK1 expression. The expression of CXCL13, CCR5, CCL19, CCR6, CCR7 and LTA decreased, likely regulated by CDKN2A overexpression. Our findings enlighten a pathway implying cell cycle arrest and decreased gene expression involved in spleen organization.
Subject(s)
Cell Cycle Checkpoints/genetics , Chemotaxis, Leukocyte/genetics , Leishmaniasis, Visceral/immunology , Spleen/immunology , Spleen/parasitology , Animals , Calcium-Binding Proteins/genetics , Calcium-Binding Proteins/metabolism , Cricetinae , Cyclin-Dependent Kinase Inhibitor p16/genetics , Cyclin-Dependent Kinase Inhibitor p16/metabolism , Female , Gene Expression Profiling , Humans , Hyperplasia/pathology , Leishmaniasis, Visceral/pathology , Leukocytes/parasitology , Leukocytes/pathology , Male , Membrane Proteins/genetics , Membrane Proteins/metabolism , Middle Aged , Spleen/pathology , TranscriptomeABSTRACT
Natural products from plants contain many interesting biomolecules. Among them, quercetin (Q), gallic acid (GA), and rutin (R) all have well-reported antileishmanial activity; however, their exact mechanisms of action are still not known. The current study is a step forward towards unveil the possible modes of action of these compounds against Leishmania donovani (the causative agent of visceral leishmaniasis). The selected compounds were checked for their mechanisms of action against L. donovani using different biological assays including apoptosis and necrosis evaluation, effects on genetic material (DNA), quantitative testing of nitric oxide production, ultrastructural modification via transmission electron microscopy, and real-time PCR analysis. The results confirmed that these compounds are active against L. donovani, with IC50 values of 84.65 µg/mL, 86 µg/mL, and 98 µg/mL for Q, GA, and R, respectively. These compounds increased nitric oxide production and caused apoptosis and DNA damage, which led to changes in the treated cells' ultrastructural behavior and finally to the death of L. donovani. These compounds also suppressed essential enzymes like trypanothione reductase and trypanothione synthetase, which are critical for leishmanial survival. The selected compounds have high antileishmanial potentials, and thus in-vivo testing and further screening are highly recommended.
Subject(s)
Antiprotozoal Agents/pharmacology , Apoptosis , DNA Damage , Flavonoids/pharmacology , Leishmania donovani/growth & development , Leishmaniasis, Visceral/pathology , Macrophages/pathology , Animals , Leishmania donovani/drug effects , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/genetics , Leishmaniasis, Visceral/parasitology , Macrophages/drug effects , Macrophages/parasitology , Mice , Mice, Inbred BALB C , NecrosisABSTRACT
Dogs are the main reservoir of Leishmania infantum in endemic regions. Canine leishmaniasis, caused by L. infantum, can progress to a chronic disease resulting in death. Vaccines have been developed with a certain degree of success. The pathogenesis of this disease is not completely understood, especially in previously vaccinated dogs. We herein described clinical data, parasite load, serum levels of cytokines, and the reservoir potential in vdogs vaccinated with the fucose-mannose ligand (FML)/QuilA saponin vaccine (Leishmune™) naturally infected (Vi) and compared to vaccinated not infected dogs (Vn). Thirty-four dogs from private owners were divided into two groups: vaccinated/infected and vaccinated/uninfected. Clinical evaluation, hematological and biochemical parameters, and serum levels of cytokines were measured by conventional methods. The parasite burden in the bone marrow was measured by quantitative real-time PCR, and the transmissibility of parasites to sand flies was assessed by xenodiagnosis. Clinical, biochemical, and hematological parameters of vaccinated infected dogs were mostly normal. Vi dogs developed mild disease with low clinical scores. Serum levels of IL-10 were higher in Vi dogs, and a strong correlation was observed in IL-4 levels and the A/G ratio in Vi dogs. These results suggest a role of TH2 response in Vi dogs, although more data is needed to better understand the disease in vaccinated dogs.
Subject(s)
Cytokines/blood , Lectins/immunology , Leishmania infantum/immunology , Leishmaniasis Vaccines/immunology , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/veterinary , Vaccination , Animals , Dogs , Female , Interleukin-4/blood , Leishmaniasis, Visceral/blood , Leishmaniasis, Visceral/pathology , MaleABSTRACT
Leishmaniasis is remaining as one of the important health problems of many countries around the world. The histopathology of the disease and the effects of the parasite on various tissues have not yet been fully elucidated. The current study aimed to evaluate the stereological features of the liver, spleen, and bone of hamsters infected with Leishmania infantum. In this experimental study, the L. infantum parasite was mass cultivated in a culture medium. Then, 15 golden hamsters were selected, of which 5 animals were considered as controls and another 10 animals were injected intravenously, with 1 × 108 promastigotes of L. infantum. Four months later, the hamsters were euthanized and impression smears were prepared from the liver and spleen. Moreover, pathology slides were prepared from the spleen, liver, and femur. The orientated method was used to obtain isotropic uniform random (IUR) sections. For stereological evaluation, the tissues were fixed with formalin buffer, and sections (4 and 25 µm thick) were prepared and stained with Heidenhain's AZAN trichrome and hematoxylin-eosin, respectively. The tissue samples were examined by stereological methods and all changes in the samples of the infected hamsters were compared with the control group. The number of hepatocyte and their nuclei volumes were significantly decreased in the Leishmania-infected group, compared to the control group. The number of Kupffer cells and their volume in the liver of the Leishmania-infected group was higher than that of the control group, and the differences were statistically significant. The volume of trabeculae and central arteries in the spleen of the Leishmania-infected group was lower than that of the control group and the number of lymphocytes and macrophages in the spleen of the Leishmania-infected group was increased compared to the control group. The trabecular volume and the number of osteoblasts and osteoclasts of the femur in Leishmania-infected animals decreased, whereas the volume of bone marrow was significantly raised. Leishmaniasis leads to changes in tissue structure and their function in the host by the involvement of various organs of the immune system including the liver, spleen, and bone. Understanding these changes are important in identifying the effective mechanisms of the parasite and host interaction.
Subject(s)
Femur/pathology , Leishmania infantum/pathogenicity , Leishmaniasis, Visceral/pathology , Liver/pathology , Spleen/pathology , Animals , Cricetinae , Eosinophils/pathology , Femur/parasitology , Hepatocytes/pathology , Kupffer Cells/pathology , Liver/parasitology , Macrophages/pathology , Mesocricetus , Osteoblasts/pathology , Osteoclasts/pathology , Osteocytes/pathology , Spleen/parasitologyABSTRACT
BACKGROUND: Visceral Leishmaniasis (VL) is a neglected tropical disease endemic to several countries including Ethiopia. Outside of Africa, kidney involvement in VL is frequent and associated with increased mortality. There is however limited data on acute kidney injury (AKI) in VL patients in East-Africa, particularly in areas with high rates of HIV co-infection. This study aims to determine the prevalence, characteristics and associated factors of AKI in VL patients in Northwest Ethiopia. METHODS: A hospital based retrospective patient record analysis was conducted including patients treated for VL from January 2019 to December 2019 at the Leishmaniasis Research and Treatment Center (LRTC), Gondar, Ethiopia. Patients that were enrolled in ongoing clinical trials at the study site and those with significant incomplete data were excluded. Data was analyzed using SPSS version 20. P values were considered significant if < 0.05. RESULTS: Among 352 VL patients treated at LRTC during the study period, 298 were included in the study. All were male patients except two; the median age was 23 years (IQR: 20-27). The overall prevalence of AKI among VL patients was 17.4% (confidence interval (CI): 13.6%-22.2%). Pre-renal azotemia (57%) and drug-induced AKI (50%) were the main etiologies of AKI at admission and post-admission respectively. Proteinuria and hematuria occurred in 85% and 42% of AKI patients respectively. Multivariate logistic regression revealed HIV co-infection (adjusted odds ratio (AOR): 6.01 95% CI: 1.99-18.27, p = 0.001) and other concomitant infections (AOR: 3.44 95% CI: 1.37-8.65, p = 0.009) to be independently associated with AKI. CONCLUSION: AKI is a frequent complication in Ethiopian VL patients. Other renal manifestations included proteinuria, hematuria, and pyuria. HIV co-infection and other concomitant infections were significantly associated with AKI. Further studies are needed to quantify proteinuria and evaluate the influence of AKI on the treatment course, morbidity and mortality in VL patients.
Subject(s)
Leishmaniasis, Visceral/physiopathology , Acute Kidney Injury/pathology , Acute Kidney Injury/physiopathology , Adolescent , Adult , Coinfection/pathology , Coinfection/physiopathology , Ethiopia , HIV Infections/pathology , HIV Infections/physiopathology , Humans , Leishmaniasis/pathology , Leishmaniasis/physiopathology , Leishmaniasis, Visceral/pathology , Middle Aged , Odds Ratio , Retrospective Studies , Risk Factors , Young AdultABSTRACT
BACKGROUND: The rapid diagnostic test (RDT) rK39 is currently being used for routine diagnosis of visceral leishmaniasis (VL) in East Africa. However, continuous monitoring of the performance of the assay, in particular its impact on the clinical decision in initiating anti-leishmanial treatment and outcomes remains needed as there are concerns about the diagnostic performance of this test. METHODS: VL patients prospectively enrolled in a diagnostic trial and with rK39 RDT were included. We evaluated the effect of rK39 testing in guiding treatment initiation and outcome. On the basis of rK39 RDT test result as well as clinical case definition for VL and microscopy examination, the clinicians decide whether to initiate VL therapy or not. Poisson regression models were used to identify factors associated with a decision to initiate VL therapy. In addition, treatment outcomes of those who received VL therapy were compared to those who received non-VL treatment. RESULTS: Of 324 VL suspects enrolled, 184 (56.8%) were rK39+ and 140 (43.2%) were rK39â. In addition, microscopy exam was done on tissue aspirates from a sub-population (140 individuals), which is 43.2% of the suspected cases, comprising of 117 (63.6%) rK39+ and only 23 (16.4%) rK39â cases. Of those with microscopy examination, only 87 (62.1%) were found positive. Among 184 (56.8%) patients without microscopy, 67 (36.4%) were rK39+, of whom 83 (65.9%) were positive by microscopy, 21 (16.7%) were negative by microscopy and 22 (17.5%) had no microscopy results. On the other hand, of those who did not receive VL treatment 58/189 (30.7%) were rK39+ and 131 (69.3%) were rK39â. Of the rK39+ cases who did not receive VL therapy, only 1 (1.7%) patient was microscopy positive, 12 (20.7%) were negative and 45 (77.6%) patients had no microscopy result. Of the rK39â cases (n = 131) who did not receive VL treatment, 16 were microscopy negative and 115 without microscopy exams. Whereas positive rK39 result [adjusted Relative Risk (aRR) 0.69; 95% CI: 0.49-0.96, p = 0.029] and positive microscopy results (aRR 0.03; 95% CI: 0.00-0.24, p = 0.001) were independently associated with VL treatment, having confirmed diagnosis other than VL (aRR 1.64; 95% CI: 1.09-2.46, p = 0.018) was independently associated with initiation of non-VL therapy. The proportion of rK39+ patients who received non-VL treatment with no improvement outcome was significantly higher when compared to those who received VL treatment (24.1%, 95% CI: 14.62-37.16 vs. 11.9%, 95%CI: 7.26-18.93; p<0.0001). CONCLUSION: The study shows that a significant proportion of patients with rK39+ results were undertreated. Failure to do microscopy was associated with lack of improved clinical outcome. Including an additional simple point-of-care assay in the diagnostic work-up is urgently needed to correctly identify VL cases and to prevent morbidity and mortality associated with the disease.
Subject(s)
Antigens, Protozoan/isolation & purification , Diagnostic Tests, Routine/standards , Leishmaniasis, Visceral/diagnosis , Protozoan Proteins/isolation & purification , Adolescent , Adult , Agglutination Tests , Antibodies, Protozoan/immunology , Antigens, Protozoan/blood , Cohort Studies , Ethiopia/epidemiology , Female , Humans , Leishmaniasis, Visceral/immunology , Leishmaniasis, Visceral/pathology , Male , Predictive Value of Tests , Prospective Studies , Protozoan Proteins/blood , Regression Analysis , Young AdultABSTRACT
BACKGROUND: Canine leishmaniosis (CanL) is a zoonotic disease caused by Leishmania infantum. Although usually transmitted by phlebotomine sand flies, infection by vertical transmission and by blood transfusion have also been reported. METHODS: We describe the very early onset of clinical leishmaniosis, starting from 2 months of age, in a litter of pups born to an infected dam and sire. Seven pups from the litter of nine living in different households showed alopecic, exfoliative dermatitis and ulcerative cutaneous lesions. All pups and both parents were tested on at least one occasion both serologically, by enzyme-linked immunosorbent assay (ELISA), and by polymerase chain reaction (PCR) targeting the Leishmania ribosomal operon internal transcribed spacer 1 region and a short fragment of the kinetoplast minicircle; positive amplicons were sequenced. RESULTS: All nine pups were PCR positive for L. infantum verified by DNA sequencing, seven were positive by conjunctival, five by blood, four by lymph node, and one by skin PCR from an ulcerative lesion. Both pups with no clinical signs were seronegative, while five of the seven pups with dermatologic abnormalities were seropositive by ELISA. The sire had typical clinical dermatologic and visceral findings of CanL, was seropositive and PCR positive for L. infantum in the lymph node and fluid from the vas deferens tested after the testes were removed by castration. The dam was sub-clinically infected and seronegative, but positive by blood, lymph node and conjunctival PCR for L. infantum. Allopurinol administered to all clinically affected dogs resulted in clinical recovery. CONCLUSIONS: Infection with L. infantum in both parents, the very early age of clinical onset among most of the pups, and the fact that the puppies were born and detected with signs of leishmaniosis in the winter, which is a season without sand fly activity in Israel, strongly suggest vertical transmission. Awareness of the possibility of vertical transmission of L. infantum and infection in littermates should be increased. It is recommended that littermates of young dogs with clinical leishmaniosis should be tested for sub-clinical infection as they may also be infectious to sand flies and thus to other dogs and to humans. Restricting the mating of infected bitches should also be considered to prevent the vertical transmission of the infection.
Subject(s)
Dog Diseases/parasitology , Fetal Diseases/veterinary , Infectious Disease Transmission, Vertical/veterinary , Leishmania infantum/isolation & purification , Leishmaniasis, Visceral/veterinary , Animals , Dog Diseases/pathology , Dog Diseases/transmission , Dogs , Female , Fetal Diseases/parasitology , Fetal Diseases/pathology , Israel , Leishmania infantum/genetics , Leishmania infantum/physiology , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/pathology , Leishmaniasis, Visceral/transmission , Male , Skin/parasitology , Skin/pathology , Uterus/parasitologyABSTRACT
Visceral leishmaniasis is one of the neglected tropical diseases caused by an intracellular parasite, Leishmania donovani. Drug resistance, adverse side effects and long treatment regimes are important limitations in achieving the effective elimination of visceral leishmaniasis. In the absence of any vaccine, chemotherapy remains a viable treatment for leishmaniasis. For effective killing of leishmania parasite, the drug molecule needs to cross the cell membrane. In the present study, marine membrane-active peptide Tachyplesin has been used against Leishmania donovani. Further, the mechanism of action and importance of cysteine amino acids of Tachyplesin in anti-leishmanial activity has been assessed. The cargo-carrying ability of Tachyplesin in L. donovani has been established. Thus, dual-use of Tachyplesin as an anti-leishmanial peptide as well as a cargo delivery vehicle makes the marine peptide an attractive therapeutic target against visceral leishmaniasis.
Subject(s)
Antimicrobial Cationic Peptides/pharmacology , DNA-Binding Proteins/pharmacology , Leishmania donovani/drug effects , Leishmaniasis, Visceral/drug therapy , Peptides, Cyclic/pharmacology , Peptides/pharmacology , Antimicrobial Cationic Peptides/chemistry , Antimicrobial Cationic Peptides/genetics , Cell Membrane/drug effects , DNA-Binding Proteins/chemistry , DNA-Binding Proteins/genetics , Humans , Leishmania donovani/pathogenicity , Leishmaniasis, Visceral/genetics , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/pathology , Peptides/chemistry , Peptides/genetics , Peptides, Cyclic/chemistry , Peptides, Cyclic/geneticsABSTRACT
BACKGROUND: Visceral leishmaniasis (VL) is severe and potentially fatal. Brazil is one of the countries with the greatest endemicity for the disease in the world. The reduction of CD4+ T lymphocytes, B cells activation and high levels of inflammatory cytokines (IL-6/IL-8/TNF/IL-1ß), plasma LPS, soluble CD14, anti-Leishmania IgG3 and low leptin levels are involved in the immunopathogenesis of VL, most associated with severe VL. Despite relapses occurring in about 4-5% of patients with VL not associated with HIV infection, the factors underlying relapses are little known. Our aim was to identify clinical, laboratory and immunological parameters that may be associated with recurrences in VL. METHODS: Fifteen VL patients recruited from Hospital Eduardo de Menezes (BH-MG) were grouped into relapsing (R-VL, n = 5) and non-relapsing (NR-VL, n = 10) and evaluated during active disease, immediately after treatment (post-treatment) and 6 months post-treatment (6mpt). Clinical and laboratory data obtained from medical records were correlated with CD4+ and CD8+ T cell counts and anti-Leishmania Igs and IL-6 plasma levels and compared to those parameters of ten healthy controls. RESULTS: During the active phase of VL, despite similarity in the clinical symptoms, the rates of thrombocytopenia, elevated transaminases (AST and ALT) and hyperbilirubinemia were higher in the NR-VL group compared to R-VL (p < 0.05), a profile reversed during the post-treatment phase. All patients had low CD4+ T counts in active phase, however, NR-VL patients had a higher gain of this cell type than R-VL in the post-treatment (p < 0.05). There was a significant reduction in IgG3 levels during the follow-up in the NR-VL group compared to the R-VL, especially at 6mpt (p < 0.05). In addition, IgG3 levels were negatively correlated with CD4+ T counts in the R-VL group (r = - 0.52). Elevated levels of IL-6 were observed in active VL and correlated with clinical markers of severity. CONCLUSIONS: During active phase of VL, the NR-VL patients presented more severe laboratorial abnormalities compared to R-VL, probably because the latter had already received previous treatment. On the other hand, R-VL exhibited greater impairment of immune reconstitution and a high degree of B lymphocyte activation, which must be a factor that favored relapses.
Subject(s)
Antibodies, Protozoan/blood , CD4-Positive T-Lymphocytes/cytology , Immunoglobulin G/blood , Leishmania/immunology , Leishmaniasis, Visceral/pathology , Adult , Amphotericin B/therapeutic use , Brazil , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Deoxycholic Acid/therapeutic use , Drug Combinations , Female , HIV Infections/complications , Humans , Interleukin-6/blood , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/immunology , Male , Middle Aged , RecurrenceABSTRACT
Leishmaniasis is a zoonotic disease in humans caused by the bite of a parasite-infected sandfly. The disease, widely referred to as "poor man's disease," affects millions of people worldwide. The clinical manifestation of the disease depends upon the species of the parasite and ranges from physical disfigurement to death if left untreated. Here, we review the past, present, and future of leishmaniasis in detail. The life cycle of Leishmania sp., along with its epidemiology, is discussed, and in addition, the line of therapeutics available for treatment currently is examined. The current status of the disease is critically evaluated, keeping emerging threats like human immunodeficiency virus (HIV) coinfection and post kala-azar dermal leishmaniasis (PKDL) into consideration. In summary, the review proposes a dire need for new therapeutics and reassessment of the measures and policies concerning emerging threats. New strategies are essential to achieve the goal of leishmaniasis eradication in the next few decades.
Subject(s)
Leishmania donovani/pathogenicity , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/pathology , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/pathology , Animals , Coinfection/pathology , Female , HIV Infections/pathology , Humans , Male , Psychodidae/parasitology , Zoonoses/pathologyABSTRACT
In canine leishmaniosis caused by the protozoan Leishmania infantum, little is known about how co-infections with or co-seropositivities for other pathogens can influence aggravation of this disease. Therefore, the objectives of this study were to evaluate the frequency of co-infections with or co-seropositivities for certain pathogens in dogs seropositive for L. infantum and their relationship with clinical signs, histological changes and L. infantum load. Sixty-six L. infantum-seropositive dogs were submitted to clinical examination, collection of blood and bone marrow, culling, and necropsy. Antibodies against Anaplasma spp., Borrelia burgdorferi sensu lato, Ehrlichia spp. and Toxoplasma gondii and Dirofilaria immitis antigens were investigated in serum. Samples from different tissues were submitted to histopathology and immunohistochemistry for the detection of Leishmania spp. and T. gondii. Quantitative real-time PCR was used to assess the L. infantum load in spleen samples. For detection of Coxiella burnetii, conventional PCR and nested PCR were performed using bone marrow samples. All 66 dogs tested positive for L. infantum by qPCR and/or culture. Fifty dogs (76%) were co-seropositive for at least one pathogen: T. gondii (59%), Ehrlichia spp., (41%), and Anaplasma spp. (18%). Clinical signs were observed in 15 (94%) dogs monoinfected with L. infantum and in 45 (90%) dogs co-seropositive for certain pathogens. The L. infantum load in spleen and skin did not differ significantly between monoinfected and co-seropositive dogs. The number of inflammatory cells was higher in the spleen, lung and mammary gland of co-seropositive dogs and in the mitral valve of monoinfected dogs. These results suggest that dogs infected with L. infantum and co-seropositive for certain pathogens are common in the region studied. However, co-seropositivities for certain pathogens did not aggravate clinical signs or L. infantum load, although they were associated with a more intense inflammatory reaction in some organs.
Subject(s)
Coinfection/blood , Coinfection/veterinary , Dog Diseases/blood , Ehrlichia canis/immunology , Ehrlichiosis/blood , Ehrlichiosis/veterinary , Leishmania infantum/immunology , Leishmaniasis, Visceral/blood , Leishmaniasis, Visceral/veterinary , Parasite Load , Toxoplasma/immunology , Toxoplasmosis, Animal/blood , Animals , Antibodies, Protozoan/blood , Coinfection/parasitology , Coinfection/pathology , Dog Diseases/parasitology , Dog Diseases/pathology , Dogs , Ehrlichiosis/parasitology , Ehrlichiosis/pathology , Female , Immunohistochemistry/methods , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/pathology , Leukocytes/immunology , Male , Myeloid Cells/immunology , Toxoplasmosis, Animal/parasitology , Toxoplasmosis, Animal/pathologyABSTRACT
Sri Lanka reports a large focus of Leishmania donovani-induced cutaneous leishmaniasis (CL) with CL as the main clinical entity. Two independent, long existed, and clinicoepidemiologically different transmission foci in the northern region (NR) and southern region (SR) were recently reported. Current project is an extension to this previous study. Clinical diversity within a profile of classical cutaneous leishmaniasis (CCL) in a focus of L. donovani-induced CL is described for the first time. Patients with laboratory confirmed CCL (n = 550) from NF and SF were evaluated. Lesions in both foci were found to have all classical developmental stages (small and large nodules, ulcerating nodules, and ulcers) and other identified changes (multiplication, ulceration, and enlargement). Main difference was in the proportions of lesions progressing in to each different stages, proportions of lesion undergoing the main changes, and in timing of these changes during the course of a lesion. Northern focus reported a smaller proportion of lesions showing enlargement and ulceration, and a longer period of time was also required for these changes when compared to same in southern focus. In northern focus, most lesions remained small and nonulcerating and showed a higher tendency to multiply while most lesions reported in southern focus enlarged and ulcerated rapidly and remained single. Current study also evidenced a wider spectrum in the rate and pattern of progression of a skin lesion and high individual variation which could mask these region-based differences. Parasitic, vector-related, or a host etiology is suggested. Slow progressing nonulcerating infections in North may be the result of a well-adopted parasite strain that coevolved with its host for a long period while inducing only a minimal host response. This could be one among many reasons for previously observed silent expansion in northern focus while southern focus remained more confined and stable over time. Small nonprogressive, nondisturbing lesions can play a major role as silent parasite reservoirs in a community. In addition, the laboratory detection rate declined significantly when lesions multiplied and enlarged indicating the need for early laboratory confirmation. Usefulness of identified features in clinical screening and management needs to be considered.
Subject(s)
Leishmania donovani/parasitology , Leishmaniasis, Cutaneous/pathology , Leishmaniasis, Cutaneous/parasitology , Leishmaniasis, Visceral/pathology , Leishmaniasis, Visceral/parasitology , Adult , Female , Humans , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Visceral/epidemiology , Male , Middle Aged , Phenotype , Sri Lanka/epidemiology , Young AdultABSTRACT
qPCR is being used for the quantification of parasite load in different tissues of dogs infected by Leishmania infantum with or without clinical manifestations. It may be employed in the diagnosis, monitoring of the infection during treatment, and clinical studies for validation of vaccines. Aimed at enhancing the molecular diagnosis and the subsequent monitoring of the infection, this study evaluated the parasite load in several tissues from dogs infected by Leishmania infantum, showing different clinical status. Thus, the qPCR was performed on skin, conjunctival swab, popliteal lymph node, and bone marrow puncture samples taken from 65 dogs naturally infected by L. infantum. Dogs were divided into three groups per clinical score: group 1 (n = 12), included animals with zero points and no clinical manifestations of the disease; group 2 (n = 35), included animals with a score ranging from 1 to 5 points and moderate clinical manifestations; and group 3 (n = 18), included dogs with a score ranging from 6 to 11 points and intensive clinical manifestations. Another analysis was performed classifying the animals into two groups, considering the presence of, or lack of clinical signs of the disease. Analyses of these results showed that the skin was the tissue with a higher parasite load, followed by popliteal lymph node and bone marrow punctures, and conjunctival swab samples having the lowest loads. Furthermore, the skin was also the tissue with the highest parasite load when evaluating the groups individually. Animals in group 3, with intensive clinical manifestations, showed a higher parasite load in different tissues when compared to animals from groups 1 and 2. Finally, animals with clinical manifestations of the disease showed a higher parasite load when compared to dogs with no manifestations. The importance of the dog as a reservoir of L. infantum in nature is reinforced by the demonstration of skin having the highest amount of parasites/µL in this study's analysis, as well as the fact that skin is the main point of access to the parasite vector. Also, a strong and positive correlation between the intensity of clinical manifestations and the increase of parasite load in the skin was observed. In conclusion, skin was the tissue that was demonstrated to be the best option for the molecular diagnosis of L. infantum infection in dogs with varying clinical statuses used in this study.
Subject(s)
Dog Diseases/pathology , Leishmaniasis, Visceral/veterinary , Animals , Dog Diseases/parasitology , Dogs , Leishmania infantum , Leishmaniasis, Visceral/parasitology , Leishmaniasis, Visceral/pathology , Parasite Load , Skin/parasitologyABSTRACT
Visceral leishmaniasis (VL) is an important zoonotic vector-borne disease and domestic dogs are considered the main domiciliary and peri-domiciliary reservoir of Leishmania (Leishmania) infantum in South America. Distinct eco-epidemiological scenarios associated to the prevalence of the disease, clusters of parasite genotypes and chemotypes of vectors population are described in Brazil, especially in the state of São Paulo (SP). In this context, the purpose of the present study is to evaluate the clinical signs, histopathological lesions, parasite load and cytokine profile by immunohistochemistry (IHC) in popliteal lymph nodes of canines naturally infected with L. infantum, from different municipalities of the state of SP. Eighty-three dogs with VL, 61 from northwest SP (NWSP) and 22 from southeast SP (SESP), were clinically classified in stage II, with no babesiosis and ehrlichiosis. Subcapsular inflammatory infiltration and histiocytosis were significantly higher in the SESP group (pâ¯=â¯0.0128; 0.0077, respectively). On the other hand, dogs from NWSP revealed 4.6-fold significantly higher parasite burden (pâ¯=â¯0.0004) and higher IHC scores of IL-1ß (pâ¯=â¯0.0275) and IL-4 (pâ¯=â¯0.0327) in the popliteal lymph node tissues, which may be associated with the susceptibility and progression of the disease in these dogs. Differences in immune response profile associated with higher parasite load in dogs can also contribute to explain the distinct eco-epidemiological patterns of VL in specific geographic regions.
Subject(s)
Cytokines/immunology , Dog Diseases/immunology , Leishmania infantum , Leishmaniasis, Visceral/veterinary , Lymph Nodes/parasitology , Animals , Brazil/epidemiology , Dog Diseases/epidemiology , Dog Diseases/parasitology , Dog Diseases/pathology , Dogs , Female , Leishmania infantum/immunology , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/immunology , Leishmaniasis, Visceral/pathology , Lymph Nodes/pathology , Male , Parasite LoadABSTRACT
A 20-year-old man from Simanjiro district in northern Tanzania presented with a 3-year history of splenomegaly, fatigue, cachexia, skin maculae, and recent onset of watery diarrhea at Kilimanjaro Christian Medical Centre (KCMC) in Northern Tanzania. Due to laboratory findings of pancytopenia, diagnostic workup included bone marrow aspiration cytology and biopsy. Although the rapid test (IT LEISH, rK39 RDT) was negative, blood smear showed amastigote forms of leishmaniasis in macrophages. Repeat bone marrow aspiration and PCR eventually confirmed visceral leishmaniasis (VL). The patient denied travel to known endemic areas of VL. Treatment was initiated with Amphotericin B, but the patient died on the fourth day of treatment from respiratory insufficiency. An autopsy revealed massive organ manifestations of VL. This is the first reported autochthonous case of VL in Tanzania. Clark and colleagues detected the vector Phlebotomus martini in Northern Tanzania in 2013, in a region bordering the district of our patient. The negative rapid test draws attention to the fact that sensitivity and specificity were found to be low in East African VL patients as displayed earlier by a Kenyan study. Therefore, tissue samples (spleen or bone marrow) remain necessary for diagnosis. The variety of symptoms in this presented case was remarkable, including the occurrence of post-kala-azar dermal leishmaniasis (PKDL) and VL at the same time. This has been described in East African VL cases before as well as the occurrence of chronic diarrhea. An elongated undiagnosed period likely led to a mixed clinical picture that included hepato-splenomegaly, PKDL, cachexia, and diarrhea.
Subject(s)
Cachexia/pathology , Diarrhea , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/pathology , Skin/pathology , Splenomegaly/pathology , Bone Marrow/pathology , Diagnostic Tests, Routine , Humans , Kenya , Leishmaniasis, Visceral/drug therapy , Liver/pathology , Male , Spleen/pathology , Tanzania , Young AdultABSTRACT
Recent anthropic activity related to the construction of the Bosquesur Green Park in a large urban setting in Madrid (Spain) has resulted in the largest reported community outbreak of human leishmaniosis in Europe. Previous phylogenetic and molecular-typing studies of parasite isolates have implicated the Leishmania infantum ITS-Lombardi genotype in this outbreak. In an unusual scenario, visceral leishmaniosis (VL) is affecting a significant number of individuals, suggesting that an increase in parasite virulence has occurred. In this work, using an in vivo BALB/c model of VL, we aimed to investigate the properties of emergent virulence of the L. infantum POL2FL7 and BOS1FL1 isolates obtained from Phlebotomus perniciosus collected in the outbreak area and compare them with those of the well-characterized strain BCN150 MON-1 isolated from a dog. The P. perniciosus specimens were collected during an entomological survey conducted in the transmission season of 2012. We observed a range of virulence phenotypes from moderately to highly aggressive after 5 weeks of infection. IV challenge of mice with outbreak isolates from sand flies induced higher splenic and liver parasite burdens, higher serological titres of specific anti-Leishmania antibodies and impaired capacities to control infection, as revealed by the arginine metabolism and low ratios of Th1/Th2 cytokine profiles analysed, compared with the corresponding measures evaluated in mice infected with the BCN150 strain. The BOS1FL1 isolate showed the highest degree of virulence among the isolates, superior to that of POL2FL7, as evidenced by the analysed biomarkers and the histopathological severity of liver lesions. These results provide insight into how L. infantum isolates from sand flies collected in the outbreak area have been able to affect not only immunosuppressed patients but also middle-aged people with normal immunocompetence in the largest human VL outbreak in Europe.
Subject(s)
Leishmania infantum/pathogenicity , Leishmaniasis, Visceral/epidemiology , Leishmaniasis, Visceral/parasitology , Phlebotomus/parasitology , Animals , Antibodies, Protozoan/blood , Arginine/metabolism , Biomarkers , Cytokines/metabolism , Disease Models, Animal , Disease Outbreaks , Female , Humans , Immunity, Humoral , Leishmania infantum/classification , Leishmania infantum/genetics , Leishmania infantum/immunology , Leishmaniasis, Visceral/immunology , Leishmaniasis, Visceral/pathology , Liver/pathology , Mice , Mice, Inbred BALB C , Phagocytes/metabolism , Phylogeny , Seasons , Spain/epidemiology , VirulenceABSTRACT
Post-kala-azar dermal leishmaniasis (PKDL) is a complication of visceral leishmaniasis (VL) that most frequently occurs after an episode of VL caused by Leishmania donovani. In this case report, we present a 21-year-old male patient with persistent skin lesions and recurrent visceral leishmaniasis (VL) due to Leishmania infantum. The patient did not respond to multiple lines of anti-leishmanial treatment (including Liposomal amphotericin B and miltefosine) and later died from cerebral lesions presumed to be secondary to persistent VL.