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1.
Parasite Immunol ; 46(5): e13037, 2024 May.
Article En | MEDLINE | ID: mdl-38720446

The treatment for visceral leishmaniasis (VL) causes toxicity in patients, entails high cost and/or leads to the emergence of resistant strains. No human vaccine exists, and diagnosis presents problems related to the sensitivity or specificity of the tests. Here, we tested two phage clones, B1 and D11, which were shown to be protective against Leishmania infantum infection in a murine model as immunotherapeutics to treat mice infected with this parasite species. The phages were used alone or with amphotericin B (AmpB), while other mice received saline, AmpB, a wild-type phage (WTP) or WTP/AmpB. Results showed that the B1/AmpB and D11/AmpB combinations induced polarised Th1-type cellular and humoral responses, which were primed by high levels of parasite-specific IFN-γ, IL-12, TNF-α, nitrite and IgG2a antibodies, which reflected in significant reductions in the parasite load in distinct organs of the animals when analyses were performed 1 and 30 days after the treatments. Reduced organic toxicity was also found in these animals, as compared with the controls. In conclusion, preliminary data suggest the potential of the B1/AmpB and D11/AmpB combinations as immunotherapeutics against L. infantum infection.


Amphotericin B , Antibodies, Protozoan , Immunotherapy , Leishmania infantum , Leishmaniasis, Visceral , Mice, Inbred BALB C , Leishmaniasis, Visceral/immunology , Leishmaniasis, Visceral/drug therapy , Animals , Amphotericin B/therapeutic use , Amphotericin B/administration & dosage , Antibodies, Protozoan/blood , Leishmania infantum/immunology , Leishmania infantum/drug effects , Mice , Immunotherapy/methods , Female , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/administration & dosage , Immunoglobulin G/blood , Parasite Load , Disease Models, Animal , Cell Surface Display Techniques , Cytokines/metabolism , Th1 Cells/immunology
2.
Ugeskr Laeger ; 186(17)2024 Apr 22.
Article Da | MEDLINE | ID: mdl-38704708

Leishmaniasis is transmitted by sandflies and involves cutaneous, mucocutaneous, or visceral disease. Sporadic, imported cases in Denmark emphasize the need for greater awareness. The incidence is stable with at least ten verified cases per year. Diagnostic methods include PCR- and antibody tests with a high positivity rate for PCR (17%) and a low positivity rate for antibody (1.4%). The latter should be used only when visceral disease is suspected. Immunosuppressed patients are at particular risk. Treatment strategies are chosen according to the severity of the condition, as argued in this review.


Leishmaniasis , Humans , Denmark/epidemiology , Leishmaniasis/diagnosis , Communicable Diseases, Imported/diagnosis , Antiprotozoal Agents/therapeutic use , Polymerase Chain Reaction , Leishmaniasis, Cutaneous/diagnosis
3.
Chem Biol Drug Des ; 103(5): e14535, 2024 May.
Article En | MEDLINE | ID: mdl-38772877

Despite efforts, available alternatives for the treatment of leishmaniasis are still scarce. In this work we tested a class of 15 quinolinylhydrazone analogues and presented data that support the use of the most active compound in cutaneous leishmaniasis caused by Leishmania amazonensis. In general, the compounds showed activity at low concentrations for both parasitic forms (5.33-37.04 µM to promastigotes, and 14.31-61.98 µM to amastigotes). In addition, the best compound (MHZ15) is highly selective for the parasite. Biochemical studies indicate that the treatment of promastigotes with MHZ15 leads the loss of mitochondrial potential and increase in ROS levels as the primary effects, which triggers accumulation of lipid droplets, loss of plasma membrane integrity and apoptosis hallmarks, including DNA fragmentation and phosphatidylserine exposure. These effects were similar in the intracellular form of the parasite. However, in this parasitic form there is no change in plasma membrane integrity in the observed treatment time, which can be attributed to metabolic differences and the resilience of the amastigote. Also, ultrastructural changes such as vacuolization suggesting autophagy were observed. The in vivo effectiveness of MHZ15 in the experimental model of cutaneous leishmaniasis was carried out in mice of the BALB/c strain infected with L. amazonensis. The treatment by intralesional route showed that MHZ15 acted with great efficiency with significantly reduction in the parasite load in the injured paws and draining lymph nodes, without clinical signs of distress or compromise of animal welfare. In vivo toxicity was also evaluated and null alterations in the levels of hepatic enzymes aspartate aminotransferase, and alanine aminotransferase was observed. The data presented herein demonstrates that MHZ15 exhibits a range of favorable characteristics conducive to the development of an antileishmanial agent.


Apoptosis , Hydrazones , Leishmaniasis, Cutaneous , Mice, Inbred BALB C , Mitochondria , Animals , Apoptosis/drug effects , Mice , Mitochondria/drug effects , Mitochondria/metabolism , Hydrazones/pharmacology , Hydrazones/chemistry , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis, Cutaneous/parasitology , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/therapeutic use , Leishmania/drug effects , Reactive Oxygen Species/metabolism , Female , Leishmania mexicana/drug effects , Membrane Potential, Mitochondrial/drug effects
4.
Vet Rec ; 194(11): e4089, 2024 Jun 01.
Article En | MEDLINE | ID: mdl-38809570

BACKGROUND: This study examined the experiences of owners of dogs with leishmaniosis who treated their dogs with daily subcutaneous meglumine antimoniate injections. The owners' perceived ease of administering the injections, the occurrence of problems and the effects on the owners and on the dog‒owner bond were evaluated. METHODS: Dogs prescribed meglumine antimoniate as a treatment for leishmaniosis were identified using the database of the veterinary pharmacy of the Faculty of Veterinary Medicine, Utrecht University. An online questionnaire was sent to the owners of these dogs to evaluate the perceived ease of administering the injections, the occurrence of problems and the effects on the owner and the dog-owner bond. RESULTS: Responses were received from 64 dog owners. Most respondents (78%) reported that administering the injections was not difficult. Pain or the development of nodules at the injection site was reported in 50% and 40% of the dogs, respectively. Polyuria was reported in 44% of the dogs. Some owners reported that administering the injections had a negative impact on their psychological wellbeing (20%), and some would have liked more veterinary support (11%). LIMITATIONS: Some questions were answered by a limited number of people, and their responses may not be representative. CONCLUSION: Dog owners remain highly motivated to persevere with meglumine antimoniate treatment and are willing to administer the injections themselves. The availability of active support when needed during the therapy cycle may further improve their acceptance of and confidence in giving the injections.


Antiprotozoal Agents , Dog Diseases , Leishmaniasis , Meglumine Antimoniate , Dogs , Animals , Meglumine Antimoniate/therapeutic use , Meglumine Antimoniate/administration & dosage , Dog Diseases/drug therapy , Leishmaniasis/veterinary , Leishmaniasis/drug therapy , Surveys and Questionnaires , Humans , Male , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/administration & dosage , Female , Ownership , Meglumine/therapeutic use , Meglumine/administration & dosage , Organometallic Compounds/administration & dosage , Organometallic Compounds/therapeutic use , Injections, Subcutaneous/veterinary
5.
J Med Chem ; 67(10): 8323-8345, 2024 May 23.
Article En | MEDLINE | ID: mdl-38722757

Leishmaniasis is a neglected tropical disease that is estimated to afflict over 12 million people. Current drugs for leishmaniasis suffer from serious deficiencies, including toxicity, high cost, modest efficacy, primarily parenteral delivery, and emergence of widespread resistance. We have discovered and developed a natural product-inspired tambjamine chemotype, known to be effective against Plasmodium spp, as a novel class of antileishmanial agents. Herein, we report in vitro and in vivo antileishmanial activities, detailed structure-activity relationships, and metabolic/pharmacokinetic profiles of a large library of tambjamines. A number of tambjamines exhibited excellent potency against both Leishmania mexicana and Leishmania donovani parasites with good safety and metabolic profiles. Notably, tambjamine 110 offered excellent potency and provided partial protection to leishmania-infected mice at 40 and/or 60 mg/kg/10 days of oral treatment. This study presents the first account of antileishmanial activity in the tambjamine family and paves the way for the generation of new oral antileishmanial drugs.


Antiprotozoal Agents , Leishmania donovani , Leishmania mexicana , Animals , Structure-Activity Relationship , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/chemistry , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/pharmacokinetics , Mice , Leishmania donovani/drug effects , Leishmania mexicana/drug effects , Drug Discovery , Humans , Female , Leishmaniasis/drug therapy , Mice, Inbred BALB C
6.
PLoS Negl Trop Dis ; 18(5): e0012175, 2024 May.
Article En | MEDLINE | ID: mdl-38768213

In Brazil, Leishmania amazonensis is the etiological agent of cutaneous and diffuse cutaneous leishmaniasis. The state of Maranhão in the Northeast of Brazil is prevalent for these clinical forms of the disease and also has high rates of HIV infection. Here, we characterized the drug susceptibility of a L. amazonensis clinical isolate from a 46-year-old man with diffuse cutaneous leishmaniasis coinfected with HIV from this endemic area. This patient underwent several therapeutic regimens with meglumine antimoniate, liposomal amphotericin B, and pentamidine, without success. In vitro susceptibility assays against promastigotes and intracellular amastigotes demonstrated that this isolate had low susceptibility to amphotericin B, when compared with the reference strain of this species that is considered susceptible to antileishmanial drugs. Additionally, we investigated whether the low in vitro susceptibility would affect the in vivo response to amphotericin B treatment. The drug was effective in reducing the lesion size and parasite burden in mice infected with the reference strain, whereas those infected with the clinical isolate and a resistant line (generated experimentally by stepwise selection) were refractory to amphotericin B treatment. To evaluate whether the isolate was intrinsically resistant to amphotericin B in animals, infected mice were treated with other drugs that had not been used in the treatment of the patient (miltefosine, paromomycin, and a combination of both). Our findings demonstrated that all drug schemes were able to reduce lesion size and parasite burden in animals infected with the clinical isolate, confirming the amphotericin B-resistance phenotype. These findings indicate that the treatment failure observed in the patient may be associated with amphotericin B resistance, and demonstrate the potential emergence of amphotericin B-resistant L. amazonensis isolates in an area of Brazil endemic for cutaneous leishmaniasis.


Amphotericin B , Antiprotozoal Agents , Drug Resistance , Amphotericin B/pharmacology , Amphotericin B/therapeutic use , Animals , Brazil , Middle Aged , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Humans , Male , Mice , Leishmania/drug effects , Leishmania/isolation & purification , Leishmania/classification , Leishmania mexicana/drug effects , Leishmania mexicana/isolation & purification , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis, Cutaneous/parasitology , HIV Infections/complications , HIV Infections/drug therapy , Parasitic Sensitivity Tests , Mice, Inbred BALB C , Leishmaniasis, Diffuse Cutaneous/parasitology , Leishmaniasis, Diffuse Cutaneous/drug therapy
7.
Eye Contact Lens ; 50(6): 279-281, 2024 Jun 01.
Article En | MEDLINE | ID: mdl-38709240

PURPOSE: To report first clinical use of novel medical treatment for Acanthamoeba keratitis. METHODS: Interventional observational case series. Two patients with Acanthamoeba keratitis were unsuccessfully treated with polihexanide (PHMB) 0.02% and propamidine 0.1% for 6 weeks, then all were shifted in a compassionate use of PHMB 0.08% with novel standardized protocol. The postinterventional follow-up of patients was at least 7 months. RESULTS: PHMB 0.08% eyedrops in a novel standardized protocol improved infection resolution and led to complete healing of the lesion after 4 weeks in the two cases. Corneal opacities and neovascularization decreased slowly, best-corrected visual acuity slightly improved and progressively increased in the further 7 months, and no infection recurrence occurred. CONCLUSIONS: This preliminary report of two cases shows promising response to polihexanide 0.08% lowering drastically the illness duration, with reduced chance of recurrence, and mostly improving patients' quality of life.


Acanthamoeba Keratitis , Biguanides , Acanthamoeba Keratitis/drug therapy , Humans , Biguanides/therapeutic use , Adult , Male , Female , Benzamidines/therapeutic use , Visual Acuity , Ophthalmic Solutions , Antiprotozoal Agents/therapeutic use
8.
PLoS Negl Trop Dis ; 18(5): e0012156, 2024 May.
Article En | MEDLINE | ID: mdl-38709850

The multifactorial basis of therapeutic response can obscure the relation between antimicrobial drug susceptibility and clinical outcome. To discern the relationship between parasite susceptibility to meglumine antimoniate (SbV) and therapeutic outcome of cutaneous leishmaniasis, risk factors for treatment failure were considered in evaluating this relationship in ninety-one cutaneous leishmaniasis patients and corresponding clinical strains of Leishmania (Viannia) panamensis. Parasite susceptibility to 32 µg SbV/mL (plasma Cmax) was evaluated in primary human macrophages, PBMCs, and U937 macrophages. Early parasitological response to treatment was determined in lesions of a subgroup of patients, and pathogenicity of Sb-resistant and sensitive clinical strains was compared in BALB/c mice. Parasite survival in cell models and patient lesions was determined by qRT-PCR of Leishmania 7SLRNA transcript. Parasite loads in BALB/c mice were quantified by limiting dilution analysis. The disparate Sb-susceptibility of parasite subpopulations distinguished by isoenzyme profiles (zymodemes) was manifest in all cell models. Notably, Sb-resistance defined by parasite survival, was most effectively discerned in U937 macrophages compared with primary human host cells, significantly higher among strains from patients who failed treatment than cured and, significantly associated with treatment failure. Each unit increase in transformed survival rate corresponded to a 10.6-fold rise in the odds of treatment failure. Furthermore, treatment failure was significantly associated with naturally Sb-resistant zymodeme 2.3 strains, which also produced larger lesions and parasite burdens in BALB/c mice than Sb-sensitive zymodeme 2.2 strains. The confounding effect of host risk factors for treatment failure in discerning this association was evidenced in comparing strains from patients with and without the defined risk factors for treatment failure. These results establish the association of natural resistance to meglumine antimoniate with treatment failure, the importance of host risk factors in evaluating drug susceptibility and treatment outcome, and the clinical and epidemiological relevance of natural Sb-resistance in L. (V.) panamensis subpopulations.


Antiprotozoal Agents , Drug Resistance , Leishmaniasis, Cutaneous , Macrophages , Meglumine Antimoniate , Meglumine , Mice, Inbred BALB C , Organometallic Compounds , Treatment Failure , Animals , Leishmaniasis, Cutaneous/drug therapy , Leishmaniasis, Cutaneous/parasitology , Meglumine Antimoniate/therapeutic use , Meglumine Antimoniate/pharmacology , Humans , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/pharmacology , Female , Meglumine/therapeutic use , Meglumine/pharmacology , Organometallic Compounds/therapeutic use , Organometallic Compounds/pharmacology , Mice , Macrophages/parasitology , Macrophages/drug effects , Macrophages/immunology , Male , Leishmania guyanensis/drug effects , Adult , Middle Aged , Young Adult , Parasite Load , Adolescent
9.
J Emerg Med ; 66(6): e690-e693, 2024 Jun.
Article En | MEDLINE | ID: mdl-38772754

BACKGROUND: Cutaneous leishmaniasis (CL) is a vector-borne parasitic infection endemic to many sub-tropical regions worldwide. In the Americas, Leishmania braziliensis is responsible for most reported CL cases. Variable symptom presentation and susceptibility to secondary infection make diagnosing CL a difficult proposition for physicians who may not encounter cases frequently. CASE REPORT: We present the case of a 50-year-old man with multiple progressive lesions, diagnosed initially as a bacterial infection, who presented to a North American emergency department after several unsuccessful trials of antibiotic therapy. Eventually, polymerase chain reaction testing of a wound biopsy sample confirmed the presence of L. braziliensis. After a complicated course, the patient's infection resolved after tailored antiparasitic therapy. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the need to include travel history in the evaluation of atypical dermatologic infections.


Leishmaniasis, Cutaneous , Humans , Male , Middle Aged , Leishmaniasis, Cutaneous/diagnosis , Leishmaniasis, Cutaneous/drug therapy , Leishmania braziliensis/pathogenicity , Antiprotozoal Agents/therapeutic use , United States
10.
Biomolecules ; 14(4)2024 Mar 27.
Article En | MEDLINE | ID: mdl-38672424

Originally developed as a chemotherapeutic agent, miltefosine (hexadecylphosphocholine) is an inhibitor of phosphatidylcholine synthesis with proven antiparasitic effects. It is the only oral drug approved for the treatment of Leishmaniasis and American Trypanosomiasis (Chagas disease). Although its precise mechanisms are not yet fully understood, miltefosine exhibits broad-spectrum anti-parasitic effects primarily by disrupting the intracellular Ca2+ homeostasis of the parasites while sparing the human hosts. In addition to its inhibitory effects on phosphatidylcholine synthesis and cytochrome c oxidase, miltefosine has been found to affect the unique giant mitochondria and the acidocalcisomes of parasites. Both of these crucial organelles are involved in Ca2+ regulation. Furthermore, miltefosine has the ability to activate a specific parasite Ca2+ channel that responds to sphingosine, which is different to its L-type VGCC human ortholog. Here, we aimed to provide an overview of recent advancements of the anti-parasitic mechanisms of miltefosine. We also explored its multiple molecular targets and investigated how its pleiotropic effects translate into a rational therapeutic approach for patients afflicted by Leishmaniasis and American Trypanosomiasis. Notably, miltefosine's therapeutic effect extends beyond its impact on the parasite to also positively affect the host's immune system. These findings enhance our understanding on its multi-targeted mechanism of action. Overall, this review sheds light on the intricate molecular actions of miltefosine, highlighting its potential as a promising therapeutic option against these debilitating parasitic diseases.


Calcium , Chagas Disease , Homeostasis , Leishmaniasis , Phosphorylcholine , Phosphorylcholine/analogs & derivatives , Humans , Phosphorylcholine/pharmacology , Phosphorylcholine/therapeutic use , Chagas Disease/drug therapy , Chagas Disease/parasitology , Chagas Disease/metabolism , Calcium/metabolism , Leishmaniasis/drug therapy , Leishmaniasis/metabolism , Leishmaniasis/parasitology , Homeostasis/drug effects , Animals , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Mitochondria/metabolism , Mitochondria/drug effects , Leishmania/drug effects , Leishmania/metabolism , Trypanosoma cruzi/drug effects , Trypanosoma cruzi/metabolism
11.
PLoS Negl Trop Dis ; 18(4): e0012127, 2024 Apr.
Article En | MEDLINE | ID: mdl-38626196

BACKGROUND: Cutaneous leishmaniasis (CL) is characterized by potentially disfiguring skin ulcers carrying significant social stigma. To mitigate systemic drug exposure and reduce the toxicity from available treatments, studies addressing new local therapeutic strategies using available medications are coming up. This review systematically compiles preclinical and clinical data on the efficacy of amphotericin B (AmB) administered locally for cutaneous leishmaniasis. METHODOLOGY: Structured searches were conducted in major databases. Clinical studies reporting cure rates and preclinical studies presenting any efficacy outcome were included. Exclusion criteria comprised nonoriginal studies, in vitro investigations, studies with fewer than 10 treated patients, and those evaluating AmB in combination with other antileishmanial drug components. PRINCIPAL FINDINGS: A total of 21 studies were identified, encompassing 16 preclinical and five clinical studies. Preclinical assessments generally involved the topical use of commercial AmB formulations, often in conjunction with carriers or controlled release systems. However, the variation in the treatment schedules hindered direct comparisons. In clinical studies, topical AmB achieved a pooled cure rate of 45.6% [CI: 27.5-64.8%; I2 = 79.7; p = 0.002), while intralesional (IL) administration resulted in a 69.8% cure rate [CI: 52.3-82.9%; I2 = 63.9; p = 0.06). In the direct comparison available, no significant difference was noted between AmB-IL and meglumine antimoniate-IL administration (OR:1.7; CI:0.34-9.15, I2 = 79.1; p = 0.00), however a very low certainty of evidence was verified. CONCLUSIONS: Different AmB formulations and administration routes have been explored in preclinical and clinical studies. Developing therapeutic technologies is evident. Current findings might be interpreted as a favorable proof of concept for the local AmB administration which makes this intervention eligible to be explored in future well-designed studies towards less toxic treatments for leishmaniasis.


Amphotericin B , Antiprotozoal Agents , Leishmaniasis, Cutaneous , Leishmaniasis, Cutaneous/drug therapy , Amphotericin B/therapeutic use , Amphotericin B/administration & dosage , Humans , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/administration & dosage , Administration, Topical , Treatment Outcome
12.
PLoS Negl Trop Dis ; 18(4): e0011635, 2024 Apr.
Article En | MEDLINE | ID: mdl-38626228

BACKGROUND: Post-kala-azar dermal leishmaniasis (PKDL) is a dermatosis which can occur after successful treatment of visceral leishmaniasis (VL) and is a public health problem in VL endemic areas. We conducted a systematic scoping review to assess the characteristics of published PKDL clinical studies, understand the scope of research and explore the feasibility and value of developing a PKDL individual patient data (IPD) platform. METHODS: A systematic review of published literature was conducted to identify PKDL clinical studies by searching the following databases: PubMed, Scopus, Ovid Embase, Web of Science Core Collection, WHO Global Index Medicus, PASCAL, Clinicaltrials.gov, Ovid Global Health, Cochrane Database and CENTRAL, and the WHO International Clinical Trials Registry Platform. Only prospective studies in humans with PKDL diagnosis, treatment, and follow-up measurements between January 1973 and March 2023 were included. Extracted data includes variables on patient characteristics, treatment regimens, diagnostic methods, geographical locations, efficacy endpoints, adverse events and statistical methodology. RESULTS: A total of 3,418 records were screened, of which 56 unique studies (n = 2,486 patients) were included in this review. Out of the 56 studies, 36 (64.3%) were from India (1983-2022), 12 (21.4%) from Sudan (1992-2021), 6 (10.7%) were from Bangladesh (1991-2019), and 2 (3.6%) from Nepal (2001-2007). Five (8.9%) studies were published between 1981-1990 (n = 193 patients), 10 (17.9%) between 1991-2000 (n = 230 patients), 10 (17.9%) between 2001-2010 (n = 198 patients), and 31 (55.4%) from 2011 onwards (n = 1,865 patients). Eight (14.3%) were randomised clinical trials, and 48 (85.7%) were non-randomised studies. The median post-treatment follow-up duration was 365 days (range: 90-540 days) in 8 RCTs and 360 days (range: 28-2,373 days) in 48 non-randomised studies. Disease diagnosis was based on clinical criterion in 3 (5.4%) studies, a mixture of clinical and parasitological methods in 47 (83.9%) and was unclear in 6 (10.7%) studies. Major drugs used for treatment were miltefosine (n = 636 patients), liposomal amphotericin B (L-AmB) (n = 508 patients), and antinomy regimens (n = 454 patients). Ten other drug regimens were tested in 270 patients with less than 60 patients per regimen. CONCLUSIONS: Our review identified studies with very limited sample size for the three major drugs (miltefosine, L-AmB, and pentavalent antimony), while the number of patients combined across studies suggest that the IPD platform would be valuable. With the support of relevant stakeholders, the global PKDL community and sufficient financing, a PKDL IPD platform can be realised. This will allow for exploration of different aspects of treatment safety and efficacy, which can potentially guide future healthcare decisions and clinical practices.


Antiprotozoal Agents , Leishmaniasis, Cutaneous , Leishmaniasis, Visceral , Humans , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Cutaneous/drug therapy , Antiprotozoal Agents/therapeutic use , Observational Studies as Topic , Clinical Trials as Topic , Feasibility Studies , Treatment Outcome , India/epidemiology , Bangladesh/epidemiology
13.
PLoS Negl Trop Dis ; 18(4): e0012078, 2024 Apr.
Article En | MEDLINE | ID: mdl-38640118

BACKGROUND: With the current treatment options for visceral leishmaniasis (VL), recrudescence of the parasite is seen in a proportion of patients. Understanding parasite dynamics is crucial to improving treatment efficacy and predicting patient relapse in cases of VL. This study aimed to characterize the kinetics of circulating Leishmania parasites in the blood, during and after different antileishmanial therapies, and to find predictors for clinical relapse of disease. METHODS: Data from three clinical trials, in which Eastern African VL patients received various antileishmanial regimens, were combined in this study. Leishmania kinetoplast DNA was quantified in whole blood with real-time quantitative PCR (qPCR) before, during, and up to six months after treatment. An integrated population pharmacokinetic-pharmacodynamic model was developed using non-linear mixed effects modelling. RESULTS: Parasite proliferation was best described by an exponential growth model, with an in vivo parasite doubling time of 7.8 days (RSE 12%). Parasite killing by fexinidazole, liposomal amphotericin B, sodium stibogluconate, and miltefosine was best described by linear models directly relating drug concentrations to the parasite elimination rate. After treatment, parasite growth was assumed to be suppressed by the host immune system, described by an Emax model driven by the time after treatment. No predictors for the high variability in onset and magnitude of the immune response could be identified. Model-based individual predictions of blood parasite load on Day 28 and Day 56 after start of treatment were predictive for clinical relapse of disease. CONCLUSION: This semi-mechanistic pharmacokinetic-pharmacodynamic model adequately captured the blood parasite dynamics during and after treatment, and revealed that high blood parasite loads on Day 28 and Day 56 after start of treatment are an early indication for VL relapse, which could be a useful biomarker to assess treatment efficacy of a treatment regimen in a clinical trial setting.


Antiprotozoal Agents , Leishmaniasis, Visceral , Nitroimidazoles , Phosphorylcholine/analogs & derivatives , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/parasitology , Humans , Antiprotozoal Agents/pharmacokinetics , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/pharmacology , Adult , Female , Male , Young Adult , Adolescent , Africa, Eastern , Amphotericin B/pharmacokinetics , Amphotericin B/therapeutic use , Amphotericin B/pharmacology , Recurrence , DNA, Kinetoplast/genetics , Parasite Load , Middle Aged , Child , Antimony Sodium Gluconate/therapeutic use , Antimony Sodium Gluconate/pharmacokinetics , Child, Preschool , DNA, Protozoan/genetics
15.
PLoS Negl Trop Dis ; 18(4): e0012134, 2024 Apr.
Article En | MEDLINE | ID: mdl-38669211

BACKGROUND: Currently available treatment options are mostly effective in achieving long-term cure in visceral leishmaniasis (VL) patients. However, there have been reports of recurrence of this illness in both immunosuppressed and immunocompetent patients. CASE PRESENTATION: We report the first case of recurrent VL relapse in a 19-year-old immunocompetent female with functional hypopituitarism (hypogonadotropic hypogonadism with central hypothyroidism) from Bangladesh, who has been treated three times previously with optimal dosage and duration- liposomal amphotericin B (LAmB) alone and in combination with miltefosine. We treated the patient successfully with a modified treatment regimen of 10 mg/kg body weight LAmB for two consecutive days along with oral miltefosine for seven days as loading dose. For secondary prophylaxis, the patient received 3 mg/kg body weight LAmB along with oral miltefosine for seven days monthly for five doses followed by hormonal replacement. The patient remained relapse free after 12 months of her treatment completion. CONCLUSION: In the absence of protective vaccines against Leishmania species and standard treatment regimen, this modified treatment regimen could help the management of recurrent relapse cases.


Amphotericin B , Antiprotozoal Agents , Hypopituitarism , Leishmaniasis, Visceral , Phosphorylcholine , Recurrence , Female , Humans , Young Adult , Amphotericin B/therapeutic use , Amphotericin B/administration & dosage , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/administration & dosage , Bangladesh , Hypopituitarism/drug therapy , Leishmaniasis, Visceral/drug therapy , Phosphorylcholine/analogs & derivatives , Phosphorylcholine/therapeutic use , Phosphorylcholine/administration & dosage , Treatment Outcome , Adult
16.
Acta Trop ; 255: 107201, 2024 Jul.
Article En | MEDLINE | ID: mdl-38604329

Reportedly, synthetic drugs such as metronidazole, furazolidone, tinidazole, and quinacrine are used for the treatment of giardiasis but are associated with adverse effects. In this study, we aimed to investigate the in vitro and in vivo effects of eucalyptol (ECT, 1,8 cineole) alone and in combination with metronidazole (MNZ) on Giardia lamblia. The effects of ECT on cell viability, plasma membrane permeability, and gene expression levels of adenylate cyclase (AK) and extracellular signal kinases 1 and 2 (ERK1 and ERK2) in trophozoites of G. lamblia were assessed. In vivo, the effects of ECT alone and in combination with MNZ were assessed on mice infected with G. lamblia. In addition, the gene expression of inflammatory genes (e.g., TNF-α, IL-1ß, and IL-10) and antioxidant genes (catalase (CAT), superoxide dismutase 1 (SOD1), glutathione peroxidase 2 (GPX2)) was determined by real-time PCR. The IC50 values of ECT, MNZ, and ECT+MNZ on trophozoites were 30.2 µg/mL, 21.6 µg/mL, and 8.5 µg/mL, respectively. The estimated Fractional inhibitory concentration index (FICI) values for ECT and MNZ were 0.28 and 0.39, respectively. The application of ECT on G. lamblia trophozoites resulted in a dose-dependent increase in plasma membrane permeability, particularly at concentrations of ½ IC50 and IC50 (P < 0.05). The treatment of infected mice with various doses of ECT, mainly in combination with MNZ for 7 days, resulted in a significant decrease (P < 0.001) in the average number and viability of cysts. ECT, especially when combined with MNZ, caused a significant (P < 0.001) reduction in the expression of TNF-α and IL-6 genes, and an increase (P < 0.05) in the expression of IL-10 genes. ECT alone and mainly in combination with MNZ leads to a significant (P < 0.001) increase in the gene expression of CAT, SOD, and GPX genes. These findings demonstrate that the use of ECT in these doses, even for 14 days, does not have any toxic effects on the function of vital liver and kidney tissues. The study findings confirmed the promising effects of ECT against G. lamblia infection both in vitro and in vivo. Considering the possible mechanisms, ECT increases plasma membrane permeability and reduces the expression levels of infectivity-related genes. In addition, ECT suppresses inflammation and oxidative stress, controlling giardiasis in mice. More studies are needed to clarify these findings.


Antiprotozoal Agents , Giardia lamblia , Giardiasis , Oxidative Stress , Animals , Giardia lamblia/drug effects , Oxidative Stress/drug effects , Mice , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Giardiasis/drug therapy , Giardiasis/parasitology , Inflammation/drug therapy , Metronidazole/pharmacology , Cell Survival/drug effects , Disease Models, Animal , Cell Membrane Permeability/drug effects , Female , Trophozoites/drug effects , Mice, Inbred BALB C , Inhibitory Concentration 50 , Cytokines/metabolism
17.
Curr Oncol ; 31(4): 2274-2277, 2024 04 17.
Article En | MEDLINE | ID: mdl-38668071

Maintenance chemotherapy is a standard treatment in patients with non-progressive advance staged IV non-squamous non-small cell lung cancer after induction therapy. Here, we report the case of a 53-year-old man undergoing a maintenance monotherapy with pemetrexed who presented prolonged pancytopenia despite filgrastim injections. A bone marrow aspiration revealed a macrophage activation syndrome with Leishmania amastigotes. A Polymerase Chest Reaction testing confirmed the diagnosis of visceral leishmaniasis. Treatment with liposomal amphotericin B was started. Oncologists should bear in mind that visceral leishmaniasis in endemic areas can potentially induce severe and prolonged pancytopenia in immunosuppressed patients, during chemotherapy in particular.


Leishmaniasis, Visceral , Lung Neoplasms , Pancytopenia , Humans , Pancytopenia/chemically induced , Leishmaniasis, Visceral/drug therapy , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/complications , Male , Middle Aged , Lung Neoplasms/drug therapy , Carcinoma, Non-Small-Cell Lung/drug therapy , Diagnosis, Differential , Pemetrexed/therapeutic use , Pemetrexed/adverse effects , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Antiprotozoal Agents/therapeutic use , Amphotericin B/therapeutic use
18.
Vet Parasitol ; 328: 110183, 2024 Jun.
Article En | MEDLINE | ID: mdl-38608378

Tropical theileriosis is a tick-borne disease that caused by Theileria annulata, and leads to substantial economic impact in endemic area. Distinguishes to other piroplasms, Theileria is the only eukaryotic parasite could transform mammalian leukocytes. At present, buparvaquone is the most effective drug used for treatment of Theileria infection. However, frequently reported of failure treatment with buparvaquone for some T. annulata isolates. Mutation of TaPIN1 was reported to be the direct reason for failure of buparvaquone treatment. Through in vitro culture, a T. annulata isolate with a TaPIN1 mutation that is similar to the reported strain was recently identified in China. In order to understand the distribution of Theileria with mutation of TaPIN1 in China, here we developed a TaqMan probe-based real-time PCR technology to detect the mutated TaPIN1 gene. The specificity, sensitivity and reproducibility of the established TaqMan Real-time PCR method were evaluated, and field cattle blood samples collected from Xinjiang Uyghur Autonomous Region were used to test its application. Among 1683 samples, 335 samples were confirmed positive for T. annulata by traditional PCR method and 34 samples were positive for buparvaquone-resistant. The TaPIN1 gene of those 34 samples was sequenced and analyzed with the published gene sequences from NCBI database. The results showed that the sequence obtained from the present study has good consistency with those published sequences. In conclusion, the TaqMan probe-based real-time PCR targeting T. annulata mutated TaPIN1 gene was successfully established and can be used to detect clinical samples to investigation of buparvaquone-resistant parasites in Xinjiang region quickly and accurately, which will be useful for guiding clinical medicine application.


Drug Resistance , Naphthoquinones , Protozoan Proteins , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity , Theileria annulata , Theileriasis , Theileria annulata/genetics , Theileria annulata/drug effects , Theileria annulata/isolation & purification , Animals , Naphthoquinones/pharmacology , Theileriasis/parasitology , Theileriasis/diagnosis , Theileriasis/drug therapy , Cattle , Real-Time Polymerase Chain Reaction/veterinary , Real-Time Polymerase Chain Reaction/methods , Drug Resistance/genetics , Protozoan Proteins/genetics , China/epidemiology , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Reproducibility of Results , Mutation
19.
Biochem Pharmacol ; 224: 116205, 2024 Jun.
Article En | MEDLINE | ID: mdl-38615918

Nitazoxanide is an FDA-approved antiprotozoal drug. Our previous studies find that nitazoxanide and its metabolite tizoxanide affect AMPK, STAT3, and Smad2/3 signals which are involved in the pathogenesis of liver fibrosis, therefore, in the present study, we examined the effect of nitazoxanide on experimental liver fibrosis and elucidated the potential mechanisms. The in vivo experiment results showed that oral nitazoxanide (75, 100 mg·kg-1) significantly improved CCl4- and bile duct ligation-induced liver fibrosis in mice. Oral nitazoxanide activated the inhibited AMPK and inhibited the activated STAT3 in liver tissues from liver fibrosis mice. The in vitro experiment results showed that nitazoxanide and its metabolite tizoxanide activated AMPK and inhibited STAT3 signals in LX-2 cells (human hepatic stellate cells). Nitazoxanide and tizoxanide inhibited cell proliferation and collagen I expression and secretion of LX-2 cells. Nitazoxanide and tizoxanide inhibited transforming growth factor-ß1 (TGF-ß1)- and IL-6-induced increases of cell proliferation, collagen I expression and secretion, inhibited TGF-ß1- and IL-6-induced STAT3 and Smad2/3 activation in LX-2 cells. In mouse primary hepatic stellate cells, nitazoxanide and tizoxanide also activated AMPK, inhibited STAT3 and Smad2/3 activation, inhibited cell proliferation, collagen I expression and secretion. In conclusion, nitazoxanide inhibits liver fibrosis and the underlying mechanisms involve AMPK activation, and STAT3 and Smad2/3 inhibition.


Antiprotozoal Agents , Nitro Compounds , Thiazoles , Animals , Mice , Thiazoles/pharmacology , Thiazoles/therapeutic use , Male , Humans , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/therapeutic use , Cell Line , Hepatic Stellate Cells/drug effects , Hepatic Stellate Cells/metabolism , Liver Cirrhosis/drug therapy , Liver Cirrhosis/metabolism , Liver Cirrhosis/pathology , Liver Cirrhosis/chemically induced , STAT3 Transcription Factor/metabolism , STAT3 Transcription Factor/antagonists & inhibitors , Smad3 Protein/metabolism , Liver Cirrhosis, Experimental/chemically induced , Liver Cirrhosis, Experimental/pathology , Liver Cirrhosis, Experimental/drug therapy , Liver Cirrhosis, Experimental/metabolism , Liver Cirrhosis, Experimental/prevention & control , Mice, Inbred C57BL , Smad2 Protein/metabolism
20.
Diagn Microbiol Infect Dis ; 109(3): 116266, 2024 Jul.
Article En | MEDLINE | ID: mdl-38643677

The aim of this study was to describe a case of a patient with ocular toxoplasmosis, which has resulted in Kyrieleis plaques formation (segmental periarteritis associated with severe inflammation) and later follow-up and alternative treatment due to documented allergy to sulfonamide. A 33-year-old Brazilian woman diagnosed with acute toxoplasmosis, initially treated with sulfonamide, developed a critical cutaneous rash. Cotrimoxazole was changed to clindamycin and pyrimethamine, and prednisone was started. The medication was maintained for 45 days. Four months later, she developed retinal lesions suggestive of toxoplasmosis with Kyrieleis plaques in the upper temporal vessels. Pyrimethamine, clindamycin, and prednisone were initiated until healing. She presented reactivation months later, and a suppressive treatment with pyrimethamine was instituted for one year. This is the first report to use the combination of clindamycin with pyrimethamine in the treatment and recurrence prophylaxis for OT in a documented allergy to sulfonamide.


Clindamycin , Pyrimethamine , Sulfonamides , Toxoplasmosis, Ocular , Humans , Female , Adult , Pyrimethamine/therapeutic use , Pyrimethamine/adverse effects , Toxoplasmosis, Ocular/drug therapy , Sulfonamides/therapeutic use , Sulfonamides/adverse effects , Clindamycin/therapeutic use , Recurrence , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Trimethoprim, Sulfamethoxazole Drug Combination/adverse effects , Drug Hypersensitivity/etiology , Brazil , Antiprotozoal Agents/therapeutic use , Antiprotozoal Agents/adverse effects , Treatment Outcome , Prednisone/therapeutic use
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