Pentavalent Antimony Associated with G-CSF in the Treatment of Cutaneous Leishmaniasis Caused by Leishmania (Viannia) braziliensis.

Cutaneous leishmaniasis (CL), caused by Leishmania braziliensis, in recent decades has shown decreasing cure rates after treatment with meglumine antimoniate (MA). Granulocyte colony-stimulating factor (G-CSF) is a cytokine associated with epithelialization and healing processes. METHODS: This study compares the effectiveness of G-CSF associated with MA in the treatment of CL. A total of 32 patients aged between 18 and 50 years with CL confirmed for L. braziliensis were included in this study. G-CSF or placebo (0.9% saline) was applied by intralesional infiltration at four equidistant points on the edges of the largest ulcer on days 0 and 15 of treatment associated with intravenous MA. RESULTS: Males predominated in the G-CSF group (59%), while females predominated in the control group (53%). Injuries to the lower limbs predominated in both study groups. The cure rate in the G-CSF group was 65% and in the control group it was 47%, 90 days after initiation of therapy. CONCLUSIONS: Our data indicate that the association of G-CSF with MA is not superior to MA monotherapy. Although not significant, the potential benefit of this combination deserves further investigation. The use of higher doses or other routes of application of G-CSF in a greater number of patients should contribute to a definitive response.

Geriatric cutaneous leishmaniasis: a retrospective analysis of 622 cases.

BACKGROUND: Cutaneous leishmaniasis (CL) is most common in childhood because children are exposed to the parasite early and, unlike adults, do not have immunity to CL. Since CL is less common in geriatric patients, clinical and epidemiological data in this age group are limited. This study aims to compare the clinical and demographic characteristics of geriatric patients diagnosed with CL with young patients. METHODS: In this retrospective study, 622 patients aged 65 and over and 6350 patients aged 19-64, who applied to Sanliurfa Oriental Boil Diagnosis and Treatment Center between January 2013 and February 2024 and were diagnosed with CL by parasitological examination, were included. Clinical and demographic characteristics of patients diagnosed with CL, such as age, gender, location of the lesion, lesion size, duration of the lesion, and treatments applied due to the diagnosis of CL, were recorded. Clinical and demographic characteristics of geriatric and young patients were compared. RESULTS: The mean age of elderly CL cases was 72.95 ± 6.54 years, and 65.2% were female. The most common clinical forms were ulcers (51.9%) and plaques (41%), respectively, in young and elderly patients. The most common locations of the lesions were upper limbs (54.8%) in all patients. The most preferred treatment method was intralesional (IL) meglumine antimoniate (MA) treatment (98.3%) in all patients. There were no difference between young and elderly CL cases in terms of mean number of lesions, average lesion duration, average lesion size, lesion location, clinical forms of lesions, and treatments options (P > 0.05). CONCLUSIONS: Based on the results of our study, it can be said that the clinical and demographic characteristics of CL are similar in young and old patients and systemic MA treatment shows similar clinical benefit in both age groups. In addition, it can be said that systemic MA therapy can be used safely in young patients and elderly patients without contraindications. IL MA therapy can be used in elderly patients where systemic MA therapy is contraindicated.

Efficacy of the treatment using a microemulsion loaded with epoxy-α-lapachone in combination with meglumine antimoniate against murine infection by Leishmania (Leishmania) amazonensis.

Leishmaniasis is a disease caused by Leishmania spp., affecting millions of people around the world. For decades, its treatment has been based on pentavalent antimonials, which notoriously cause toxic side effects in patients. In this study, epoxy-α-lapachone incorporated into an oil-in-water-type microemulsion (ELAP-ME) and meglumine antimoniate (MA) were assayed in monotherapy and in combination (ELAP-ME/MA) in BALB/c mice infected with Leishmania (Leishmania) amazonensis. In general, there was a reduction in paw lesion size (up to 37% reduction) and decreases of parasite loads in the footpad (∼40%) and lymph nodes (∼31%) of animals treated with ELAP-ME/MA, when compared to the non-treated control groups. Analyses of serum biochemical parameters revealed that the ELAP-ME/MA showed lower renal and hepatic toxicity when compared to MA 2-doses/week monotherapy. These findings indicate that the ELAP-ME/MA combination may be a promising approach for the treatment of cutaneous leishmaniasis.

Treatment of leishmaniasis with chemotherapy and vaccine: a mathematical model.

Leishmaniasis, an infectious disease, manifests itself mostly in two forms, cutaneous leishmaniasis (CL) and, a more severe and potentially deadly form, visceral leishmaniasis (VL). The current control strategy for leishmaniasis relies on chemotherapy drugs such as sodium antimony gluconate (SAG) and meglumine antimoniate (MA). However, all these chemotherapy compounds have poor efficacy, and they are associated with toxicity and other adverse effects, as well as drug resistance. While research in vaccine development for leishmaniasis is continuously progressing, no vaccine is currently available. However, some experimental vaccines such as LEISH-F1+MPL-SE (V) have demonstrated some efficacy when used as drugs for CL patients. In this paper we use a mathematical model to address the following question: To what extent vaccine shots can enhance the efficacy of standard chemotherapy treatment of leishmaniasis? Starting with standard MA treatment of leishmaniasis and combining it with three injections of V , we find, by Day 84, that efficacy increased from 29% to 65-91% depending on the amount of the vaccine. With two or just one injection of V , efficacy is still very high, but there is a definite resurgence of the disease by end-time.

A Randomized, Controlled, Noninferiority, Multicenter Trial of Systemic vs Intralesional Treatment With Meglumine Antimoniate for Cutaneous Leishmaniasis in Brazil.

BACKGROUND: Meglumine antimoniate (MA) remains the main treatment for cutaneous leishmaniasis (CL). Uncontrolled studies suggest that intralesional MA (IL-MA) may be noninferior and safer than systemic MA (S-MA). METHODS: Multicenter, randomized, controlled, open-label, phase 3 clinical trial to evaluate the efficacy and toxicity of IL-MA in 3 infiltrations at 14-day intervals compared with S-MA (10-20 mg Sb5+/kg/day, 20 days) for CL, with noninferiority margin of 20%. Primary and secondary outcomes were definitive cure at day 180 and epithelialization rate at day 90 of treatment, respectively. A 2-year follow-up was performed to assess relapses and emergence of mucosal lesions. Adverse events (AEs) were monitored according to the Division of AIDS AE grading system. RESULTS: We evaluated 135 patients. The cure rates (95% confidence interval) for IL-MA and S-MA treatment were, respectively, 82.8% (70.5-91.4) and 67.8% (53.3-78.3) per protocol (PP) and 70.6% (58.3-81.0) and 59.7% (47.0-71.5) per intention to treat (ITT). The epithelialization rates of the IL-MA and S-MA treatment were, respectively, 79.3% (66.6-88 + 8) and 71.2% (57.9-82.2) PP and 69.1% (55.2-78.5) and 64.2% (50.0-74.2) ITT. AEs in the IL-MA and S-MA groups were, respectively, clinical, 45.6% and 80.6%; laboratory, 26.5% and 73.1%; and electrocardiogram, 8.8% and 25.4%. Ten participants in the S-MA group and 1 in the IL-MA group were discontinued due to severe or persistent AEs. CONCLUSIONS: IL-MA provides a similar cure rate and results in less toxicity compared with S-MA and may be used as first-line therapy for CL patients. CLINICAL TRIALS REGISTRATION: REBEC: RBR-6mk5n4.

Comparación de la eficacia y toxicidad del estibogluconato de sodio y antimoniato de meglumina en el tratamiento de leishmaniasis cutánea en Perú / Efficacy and safety of sodium stibogluconate compared to meglumine antimoniate in the treatment of cutaneous leishmaniasis in Peru

Objetivos : Comparar la eficacia y toxicidad del antimoniato de meglumina (AM) y estibogluconato sódico (EGS) en el tratamiento de leishmaniasis cutánea (LC) en un hospital general. Material y métodos : Serie de casos comparativa de 193 pacientes con LC tratados en tres ensayos clínicos con AM (n=69) y EGS (n=124) durante 2001-2010. La administración de ambas drogas fue vía endovenosa lenta de 20 mg Sb5+/kg/día por 20 días consecutivos siguiendo las normativas de la OPS y OMS. La información clínica, toxicidad y eficacia fue obtenida de las historias clínicas almacenadas en el centro de investigación según la normativa local e internacional. Resultados : Las características demográficas fueron similares entre grupos, pero el tamaño y número de lesiones fueron mayores en el grupo AM. La eficacia del tratamiento con AM fue 76,0% versus 68,4% con EGS (p=0,340) y 55,1% versus 50,8% (p=0,570) en el análisis por protocolo y de intención de tratar, respectivamente. No se observaron efectos adversos inmediatos. Los síntomas más frecuentemente reportados fueron disgeusia (37,0%), mareos (32,0%), cefalea (36,0%), artralgias (31,0%) y linfangitis (21,0%). Los tres primeros síntomas, así como elevación de transaminasas, leucopenia, trombocitopenia y QTc prolongado fueron frecuentes en el grupo EGS, pero clínica y estadísticamente no significativos. El tratamiento fue suspendido definitivamente por toxicidad severa únicamente con EGS por emesis refractaria (2 participantes) y QTc prolongado con extrasístoles (1 participante). Conclusiones : La eficacia del tratamiento con AM y EGS fue comparable. La administración endovenosa de ambos no produjo efectos adversos inmediatos, aunque sí alteraciones clínicas y laboratoriales usuales.

SUMMARY Objectives : To compare the efficacy and safety of sodium stibogluconate (SS) and meglumine antimoniate (MA) in the treatment of cutaneous leishmaniasis (CL) in a general hospital. Methods: Case-series of 193 patients with CL treated in three clinical trials with MA (n=69) and SS (n=124) during 2001-2010. Both study drugs were administered intravenously at a slow speed at 20 mg Sb5+/kg/day for 20 consecutive days following WHO-PAHO recommendations. Clinical and safety data were gathered from clinical files. Results: Demographic characteristics were similar between the study groups, but the size and number of lesions were higher in the MA group. Efficacy was 76.0% in the MA vs. 68.4% in the SS group (p=0.340) and 55.1% vs. 50.8% (p=0.570) in the per protocol and intention to treat analysis. respectively. Side effects more frequently reported were dysgeusia (37.0%). dizziness (32.0%). headache (36.0%). arthralgia (31.0%) and lymphangitis (21.0%). These first three symptoms as well as elevation of transaminases, leukopenia, thrombocytopenia and prolonged QTc were numerically more frequent in the SS group but without reaching statistical significance. Treatment was stopped definitively for severe toxicity in the SS group due to refractory emesis (two patients) and prolonged QTc (one patient). Conclusions: The efficacy of MA and SS is comparable. The intravenous administration of these compounds did not produce immediate reactions, but it was associated with unusual clinical and laboratory abnormalities.

Use of N-acetylcysteine as treatment adjuvant regulates immune response in visceral leishmaniasis: Pilot clinical trial and in vitro experiments.

This investigation aimed to assess the effect of N-acetylcysteine (NAC) as an adjuvant treatment to alleviate visceral leishmaniasis (VL). The present work includes both blinded randomized clinical intervention and experimental in vitro studies. The clinical trial included 60 patients with VL randomly allocated into two groups: a test group (n = 30) treated with meglumine antimoniate plus NAC (SbV + NAC) and a control group (n = 30) treated with meglumine antimoniate only (SbV). The primary outcome was clinical cure (absence of fever, spleen and liver sizes reduction, and hematological improvement) in 180 days. The cure rate did not differ between the groups; both groups had similar results in all readout indices. The immunological parameters of the patients treated with SbV + NAC showed higher sCD40L in sera during treatment, and the levels of sCD40L were negatively correlated with Interleukin-10 (IL-10) serum levels. In addition, data estimation showed a negative correlation between the sCD40L levels and the spleen size in patients with VL. For the in vitro experiments, peripheral blood mononuclear cells (PBMCs) or PBMC-derived macrophages from healthy donors were exposed to soluble Leishmania antigen (SLA) or infected with stationary promastigotes of Leishmania infantum in the presence or absence of NAC. Results revealed that NAC treatment of SLA-stimulated PBMCs reduces the frequency of monocytes producing IL-10 and lowers the frequency of CD4+ and CD8+ T cells expressing (pro-)inflammatory cytokines. Together, these results suggest that NAC treatment may modulate the immune response in patients with VL, thus warranting additional investigations to support its case use as an adjuvant to antimony therapy for VL.

Comparison Of Oral Dapsone With Intramuscular Meglumine Antimoniate In Cutaneous Leishmaniasis.

BACKGROUND: Many drugs are effective are used as second line treatment for cutaneous leishmaniasis. Dapsone therapy is tolerated well and cost effective. The aim of present study is to determine the efficacy of oral dapsone in comparison with intramuscular meglumine antimoniate in patients with cutaneous leishmaniasis and thus find out an effective second line treatment agent. METHODS: This randomized controlled trial was carried out at dermatology department, of tertiary care centre Rawalpindi, Pakistan from November 2017 to June 2018. Hundred biopsy proven patients of cutaneous leishmaniasis completed the study with 50 patients in two group. Group A received intramuscular meglumine antimoniate (15 mg/kg/day). Group B received oral dapsone2.5 mg /kg/body weight /day (200 mg per day). Efficacy of therapeutic response was noted at the end of treatment. Data was analyzed with statistical analysis program (IBM-SPSS V22). Chi-square test was applied to compare efficacy, p value of ≤0.05 was significant. Stratification of data with respect to age, gender, duration of disease, number of lesions and weight was done to see their effect on treatment efficacy. Post stratification chi-square test for both groups was applied (p≤0.05 considered significant). RESULTS: A total of 100 participants took part in the study. Duration of treatment (p-value <0.001) and the efficacy of the drugs (p-value=0.020) were significant. Meglumine antimoniate therapy group displayed a comparatively fast-paced recovery in (21- 40 days) whereas Dapsone group showed better recovery in (41-60 days) in their lesions. CONCLUSIONS: Dapsone is an effective treatment for cutaneous Leishmaniasis.

Comparison Of Efficacy Of Miltefosine Versus Meglumine Antimonate In The Treatment Of Cutaneous Leishmaniasis.

BACKGROUND: Cutaneous Leishmaniasis is a morbid condition that generates stigmatization and disfiguring scars. Pakistan is among the ninety-eight countries where cutaneous Leishmaniasis is endemic. Purpose of study was to compare the efficacy of miltefosine and meglumine antimoniate in the treatment of cutaneous Leishmaniasis. METHODS: All patients with cutaneous Leishmaniasis (CL) who met the inclusion criteria were divided into two groups using the envelop method. Capsule Miltefosine 50 mg (2.5 mg/ kg) was given to group A, while intralesional Glucantime injection was given to group B. The treatment's efficacy was evaluated after four weeks and again after eight weeks. RESULTS: Out of 74 patients, 37 patients were included in each group. In group A (miltefosine group), 56.75% were males, and 43.25% were females. In group B (meglumine antimoniate group), 62% were males, while 38% were females (p=0.63). The mean age was 32.81 years±12.09 SD, the mean duration of the disease was 5.4 months±2.3 SD and the mean number of lesions was 2.56±1.33 SD. The efficacy of Miltefosine and meglumine antimoniate (I/L) was 91.9% and 56.75%, respectively (p<0.001). CONCLUSIONS: Miltefosine was more effective than intralesional meglumine antimoniate in the treatment of cutaneous Leishmaniasis (p<0.001).

Leishmaniasis.

Leishmaniasis caused by Leishmania infantum is an important zoonotic disease transmitted by sand flies with a high prevalence of infection in dogs and cats in regions whereby transmission occurs. Clinical disease is systemic with variable presenting signs and degrees of severity. It affects the skin, lymph nodes, eyes, bone marrow, kidneys, and other organs. The clinical findings in dogs and cats with L. infantum infection are generally similar. Subclinical infection of canines and felines in endemic areas is frequent. Long-term treatment of the disease with allopurinol, or combination of allopurinol with meglumine antimoniate or miltefosine, is needed, and clinical relapse is probable.

Fat necrosis: A neglected side effect of intramuscular injections.

Panniculitis has various etiologies. One of the less common causes is trauma and hence traumatic fat necrosis (FN). These soft tissue injuries usually appear on the shins, thighs, breasts, arms, and buttocks. FN is mainly caused by trauma and may be associated with other conditions such as pancreatic disease. FN arising after intramuscular injections is uncommon and usually appears as firm, encapsulated, mobile, nontender, and solitary or multiple subcutaneous nodules. We report an interesting case of FN caused by intramuscular injections of cefazolin and meglumine antimoniate (MA) in a 38-year-old female patient. MA is regarded as the first-line systemic treatment for cutaneous leishmaniasis (CL). However, these drugs are not devoid of various potentially adverse reactions.

Therapeutic effect of Prosopis strombulifera (LAM) BENTH aqueous extract on a murine model of cutaneous leishmaniasis.

Background and aim: Prosopis strombulifera (Lam.) Benth is a rhizomatous shrub native from different zones of Argentine Republic. P. strombulifera aqueous extract (PsAE) has different effects and several biological activities have been reported. The goal of this study was to analyze the activity of PsAE on a murine model of cutaneous leishmaniasis caused by Leishmania amazonensis. Experimental procedure: PsAE was orally administered at 150 mg/animal/day on BALB/c mice infected in the right footpad (RFP) with 1 × 105 promastigotes of L. amazonensis. As a chemotherapeutic control of treatment, animals receive a commercial form of meglumine antimoniate (MA) (Glucantime®, Aventis, Paris, France). Results and conclusion: We observe that the size of RFP lesions of infected mice without treatment showed a grade of inflammation, ulceration and necrosis at the site of infection much greater than that observed with PsAE or MA treatment. Moreover, PsAE was capable of decreasing parasite burden and splenic index. Furthermore, PsAE treated mice showed a significant decrease in O.D. of total anti-Leishmania IgG antibody responses against L. amazonensis. This decrease was similar to those observed when the reference drug, MA, was used. This would indicate that PsAE treatment inhibits or delays disease progression in mice. In conclusion, our findings suggest that PsAE could be a potential candidate to be used, as a new therapeutic strategy, to treat cutaneous leishmaniasis caused by L. amazonensis.

Involvement of tryparedoxin peroxidase (TryP) and trypanothione reductase (TryR) in antimony unresponsive of Leishmania tropica clinical isolates of Iran.

Clinical resistance to pentavalent antimonial compounds has long been recognized as a major problem in the treatment of human leishmaniasis. Trypanothione metabolism, the main form of thiol, has shown to play a central role in antimony resistance of laboratory-generated resistant Leishmania spp. and field-isolated resistant L. donovani; but the mechanism of antimony resistance in the clinical isolates of L. tropica causing anthroponotic cutaneous leishmaniasis (ACL) is less studied. Patients were selected among confirmed positive ACL cases who referred to Pasteur Institute of Iran, Tehran, from endemic regions of north-east and south of Iran. L. tropica clinical isolates were collected from patients who were either treatment-responsive (MAS=S1 to S5) or unresponsive (MAR=R1 to R4) to Glucantime® (meglumine antimoniate=MA). Isolates were tested for sensitivity to trivalent antimony (SbIII) in promastigotes and to pentavalent antimony (SbV) in intracellular amastigotes stages. Intracellular thiol levels were assayed and trypanothione-dependent components, including trypanothione reductase (TR) and tryparedoxin peroxidase I (TryP) were analysed at protein level and enzymatic activity in isolates. The MAR isolates had an approximate two fold increase in the levels of intracellular thiols (P< 0.05) accompanied by an average 5-10 fold increase in in vitro resistance to antimony. TryP was amplified at the protein level in all MAR strains as compared to the MAS strains (range: 2.8-5.6 fold). All MAR isolates metabolized H2O2 at higher rates than MAS isolates (8.55±0.75 nmol/min/mg vs. 3.14±0.36 nmol/min/mg) (P< 0.05). In addition, levels of TryR protein were also markedly elevated in 3 out of 4 MAR isolates (range: 2.2-4.1 fold). This was accompanied by overexpressed TryR activity (mean level of 46.83±2.43 for extracts of MAR vs. 20.98±3.02 for MAS strains) (P< 0.05). Elevated levels of TryP, active enzyme in peroxide detoxification, were observed in MAR parasites resulting in an increased metabolism of H2O2. TryR activity was overexpressed on average in extracts of MAR strains, but not in all isolates. Enhanced anti-oxidant defenses through thiol metabolism may play a significant role in clinical resistance of ACL patients to Glucantime.

Pentoxifylline in the Treatment of Cutaneous Leishmaniasis: A Randomized Clinical Trial in Colombia.

Addition of the immunomodulator pentoxifylline (PTX) to antimonial treatment of mucosal leishmaniasis has shown increased efficacy. This randomized, double-blind, placebo-controlled trial evaluated whether addition of pentoxifylline to meglumine antimoniate (MA) treatment improves therapeutic response in cutaneous leishmaniasis (CL) patients. Seventy-three patients aged 18−65 years, having multiple lesions or a single lesion ≥ 3 cm were randomized to receive: intramuscular MA (20 mg/kg/day × 20 days) plus oral PTX 400 mg thrice daily (intervention arm, n = 36) or MA plus placebo (control arm, n = 37), between 2012 and 2015. Inflammatory gene expression was evaluated by RT-qPCR in peripheral blood mononuclear cells from trial patients, before and after treatment. Intention-to-treat failure rate was 35% for intervention vs. 25% for control (OR: 0.61, 95% CI: 0.21−1.71). Per-protocol failure rate was 32% for PTX, and 24% for placebo (OR: 0.50, 95% CI: 0.13−1.97). No differences in frequency or severity of adverse events were found (PTX = 142 vs. placebo = 140). Expression of inflammatory mediators was unaltered by addition of PTX to MA. However, therapeutic failure was associated with significant overexpression of il1ß and ptgs2 (p < 0.05), irrespective of study group. No clinical benefit of addition of PTX to standard treatment was detected in early mild to moderate CL caused by Leishmania (V.) panamensis.

Positivity, diagnosis and treatment follow-up of cutaneous leishmaniasis in war-affected areas of Bajaur, Pakistan.

This study was conducted to explore the frequency of positivity of cutaneous leishmaniasis (CL) in the tribal district Bajaur located near the Pak-Afghan border. The present study was conducted at the Leishmaniasis Center of Headquarter Hospital Khar District Bajaur, Pakistan. In total, 646 patients were recruited and included in the study after ethical approval and consent from the patients. CL was confirmed by taking blood samples from the sides of the lesion and observing them under a microscope using Giemsa staining. Information about demographic factors was collected from the study participants with a questionnaire and analyzed by SPSS. It was found that 73.8% of suspected patients were positive and 26.2% were negative for CL. There were 51.9% male and 48.1% female patients. The most frequently affected site was the face (42.6%), and most of the patients (85.8%) had only one lesion. The positivity of CL was higher among those under age 15 years. The area of most positivity, with 45.2% of the cases, was Tehsil Mamund. Most of the patients (46.6%) lived in stone houses, with 98.6% of patients having domestic animals in their houses. Approximately 198 patients were treated with intramuscular and intralesional injections of meglumine antimoniate, and their weekly follow-up revealed that 48% of patients recovered, while the remaining patients left the course of treatment at different stages of therapy. The positivity of CL is high in this area and is confirmed by the detection of Leishmania amastigotes in the blood collected from their lesions. Socioeconomic factors are the main underlying causes of the rapid spread of this disease and meglumine antimoniate is an effective drug.

Comparative evaluation of meglumine antimoniate encapsulated in a mixture of conventional and PEGylated liposomes and immunotherapy using an anti-canine IL-10 receptor-blocking monoclonal antibody on canine visceral leishmaniasis.

This study compared the therapeutic potential of the chemotherapy using meglumine antimoniate encapsulated in a mixture of conventional and PEGylated liposomes (Nano Sbv) and immunotherapy with anti-canine IL-10 receptor-blocking monoclonal antibody (Anti IL-10R) on canine visceral leishmaniasis (CVL). Twenty mongrel dogs naturally infected by L. infantum, displaying clinical signs of visceral leishmaniasis were randomly divided in two groups. In the first one, nine dogs received six intravenous doses of a mixture of conventional and PEGylated liposomes containing meglumine antimoniate at 6.5 mg Sb/kg/dose. In the second one, eleven dogs received two intramuscular doses of 4 mg of anti-canine IL-10 receptor-blocking monoclonal antibody. The animals were evaluated before (T0) and 30, 90, and 180 days after treatments. Our major results demonstrated that both treatments were able to maintain hematological and biochemical parameters, increase circulating T lymphocytes subpopulations, increase the IFN-γ producing T-CD4 lymphocytes, restore the lymphoproliferative capacity and improve the clinical status. However, although these improvements were observed in the initial post-treatment times, they did not maintain until the end of the experimental follow-up. We believe that the use of booster doses or the association of chemotherapy and immunotherapy (immunochemotherapy) is promising to improve the effectiveness of treating CVL for improving the clinical signs and possibly reducing the parasite burden in dogs infected with Leishmania infantum.

Mitogen-Activated Protein Kinase and Aquaglyceroporin Gene Expression in Treatment Failure Leishmania major.

PURPOSE: Leishmaniasis comprises various clinical forms mainly including cutaneous, muco-cutaneous, and visceral leishmaniasis; caused by Leishmania species. Antimoniate is the first-line treatment but some cases showed no response to treatment in the worldwide. In this study, mitogen-activated protein kinase (MAPK) and aquaglyceroporin 1 (AQP1) gene expressions were assessed in treatment failure clinical isolates of Leishmania major. Also, molecular and phylogenic analyses of the mentioned isolates were performed. METHODS: Samples were obtained from the patients with suspicious CL referred to the laboratory of Diagnosis Center, Gorgan Province, Iran, from October 2016 to December 2019. Detection and identification of the parasite was performed. The genes expressions of MAPK1 and AQP1 were done using SYBR Green real-time PCR. The AQP1 gene from the isolates with treatment failure was sequenced and analyzed using BLAST and multiple alignments. The phylogenic analysis was done using MEGA7. The statistical analysis was done using SPSS 16.0 by non-parametric Mann-Whitney U test. RESULTS: All clinical isolates were detected L. major. The mean AQP1 and MAPK1 gene expressions in treatment failure isolates were 58.71 and 6.139 fold less than the ones in treatment response isolates, respectively. Based on the AQP1 gene sequence, a nucleotide change of aspartic acid with asparagine at the site 234 was observed. Phylogenic tree analysis showed three groups with the minimum dissimilarity of 0.008 between TF isolates with the standard L. major strains. CONCLUSION: We showed that MAPK1 and AQP1 may have critical roles in response to antimoniate in clinical isolates L. major in this study.

Improved efficacy of meglumine antimoniate incorporated in anionic liposomes against Leishmania infantum infecting canine macrophages.

OBJECTIVES: Leishmaniasis is a zoonotic disease and several drugs have been used in the treatment, including meglumine antimoniate (AME). The chemotherapy reaches clinical cure but does not eliminate parasites, contributing to drug resistance. To improve AME efficacy we incorporated it in anionic liposomes. The antiparasitic activity and intracellular localization were investigated in canine macrophages infected with Leishmania infantum. METHODS: Liposomes (L-AME) is composed of egg phosphatidylcholine, cholesterol, palmitoyl oleoyl phosphatidyl serine and α-tocopherol (4 : 3 : 0.4 : 0.07 mol%) plus AME. L-AME size, polydispersity, zeta potential and morphology were analysed as well as antileishmanial activity and intracellular localization in DH82 macrophages. KEY FINDINGS: Liposomes (360 nm) zeta potential range from -40 to -65 mV, had 23% encapsulation efficiency and were stable for 180 days at 4°C. Free AME was cytotoxic towards L. infantum infected macrophages (ID50 = 0.012 M) while L-AME did not reduce cell viability. L-AME colocalized with parasites inside macrophages in a time-dependent manner, and reduced the percentage of infected cells and the number of intracellular parasites, decreasing the infection index (75-80%) twice as compared with AME treatment. CONCLUSIONS: Liposomal AME is a promising delivery system for treating visceral leishmaniasis, improving meglumine efficacy against L. infantum and minimizing its cytotoxicity towards canine macrophages.