Post-kala-azar Dermal Leishmaniasis Research Articles

Atypical cutaneous leishmaniasis: a new challenge to VL elimination in South-East Asia

Visceral leishmaniasis (VL) caused by L. donovani in South-East Asian endemic countries including India, Nepal and Bangladesh has been the primary focus of the ongoing VL elimination program. With a major reduction in VL cases resulting from the elimination program during the last two decades, the efforts are now focused on the challenges posed by potential reservoirs within the asymptomatic cases, HIV-co-infection VL cases and Post Kala-azar Dermal Leishmaniasis (PKDL) cases that continue to sustain the parasite transmission cycle in known and newer endemic zones. This article brings attention to a new potential parasite reservoir in the form of atypical cutaneous leishmaniasis (ACL) cases caused by novel L. donovani genetic variants. L. donovani mediated ACL is an emerging phenomenon in recent endemic sites that now justify a need for implementing molecular surveillance tools to identify region-specific L. donovani variants with dermotropic capabilities and potential to revert to visceral disease. A timely detection of novel ACL causing L. donovani genetic lineages in South-East Asian endemic regions is necessary to halt the spread of ACL and is potentially crucial for the sustainability of the advances made by the VL elimination.

Rapid antigen detection test for diagnosis of post kala-azar dermal leishmaniasis: application of CL Detect™ rapid test for active case detection in the endemic area.

Post-kala-azar dermal leishmaniasis (PKDL) is a skin condition that occurs in a small percentage of people who have been cured of visceral leishmaniasis (VL), and contributes to transmission of VL. The rK39 rapid test cannot decisively diagnose PKDL due to presence of antileishmanial antibodies from past VL episodes. CL Detect™ Rapid Test, an in-vitro diagnostic test that detects Leishmania antigen peroxidoxin, was assessed for diagnosing PKDL. The CL Detect RDT had 73.3% sensitivity and 100% specificity in the study. The test can be used as a primary screening tool to monitor PKDL in endemic regions and identify active Leishmania infection.

Comparative Efficacy of Current and Emerging Therapies for Cutaneous and Visceral Leishmaniasis: A Global Perspective

Leishmaniasis treatment has faced challenges with pentavalent antimonials, historically used but now showing resistance and high failure rates. The World Health Organization (WHO) recommended higher doses, but resistance in Nepal and misuse persist. Antimonials are no longer the preferred treatment for visceral leishmaniasis (VL) in the Indian subcontinent but are still used for cutaneous leishmaniasis (CL). Amphotericin B, especially liposomal amphotericin B (L-AmB), has become the preferred treatment for VL in the Indian subcontinent, with high efficacy and shorter treatment courses. Genetic insights into leishmaniasis reveal that parasite species and host immune responses are key factors in disease variation. Genetic analysis of atypical parasite isolates shows that genetic variations can lead to different disease patterns. Whole genome sequencing and proteomic analyses offer fresh insights into how parasite genes and proteins impact drug resistance, post-kala-azar dermal leishmaniasis (PKDL), and unusual disease presentations. Variations in hereditary unit copy numbers and single nucleotide polymorphisms contribute to genetic diversity and distinct tissue distribution, leading to distinct disease patterns. Genomic markers for drug resistance in Leishmania parasites include ATP-binding cassette (ABC) transporters, amino acid permease 3 (AAP3), and proteins like phosphoglycerate kinase (PGK) and mitogen-activated protein kinase (MAPK). These markers are associated with efflux of thiols and metals, antimony resistance, and protection against oxidative stress. Additionally, key proteins and enzymes in antioxidant defense mechanisms, such as iron superoxide dismutase-A (FeSOD-A), folate transporter 1 (FT1), and heat shock protein 83 (HSP83), play roles in drug resistance and parasite survival.

Treatment Outcomes of Single-Dose Liposomal Amphotericin B-Treated Visceral Leishmaniasis Patients and Factors Affecting Outcome in Bihar, India.

An assessment of the treatment outcomes of single-dose liposomal amphotericin B, implemented in 2010, had not been conducted until this study. This prospective cross-sectional study encompassed 527 cases, comprising 470 (89%) cases of visceral leishmaniasis (VL) and 57 (11%) cases of post-kala-azar dermal leishmaniasis (PKDL). The male proportion was higher (55% for VL), and the mean (±SD) age was 39.2 (±33.9) years. Among VL cases (426) treated with single-dose liposomal amphotericin B, 402 cases were cured at the 6-month follow-up, resulting in a cure rate of 95%, whereas fewer than 1% (0.9%) experienced unsuccessful outcomes and 4.1% faced relapse. A statistically highly significant difference in treatment outcomes (successful versus unsuccessful) was observed between males and females (P = 0.0005). Males had higher odds of successful outcomes compared with females, with an odds ratio of 5.03 (95% CI: 1.84-13.74). Those aged ≤23 years had higher odds of successful outcomes than unsuccessful outcomes, with an odds ratio of 6.82 (95% CI: 2.29-20.33). Patients with PKDL had a mean (±SD) age of 28.5 (±10.6) years, with 63% being male. Among the 57 PKDL cases, 21 (37%) had been treated with single-dose liposomal amphotericin B, whereas others had received alternative drugs. The median duration of PKDL development for single-dose liposomal amphotericin B was significantly shorter (14.5 months), with a statistically significant difference (P <0.001) compared with other drugs. The current treatment strategy necessitates continuous close monitoring and reviews to ensure consistent and improved outcomes.

Immune response to viscerotropic Leishmania: a comprehensive review.

L. donovani and L. infantum infections are associated with a broad clinical spectrum, ranging from asymptomatic cases to visceral leishmaniasis (VL) with high mortality rates. Clinical manifestations such as post-kala-azar dermal leishmaniasis (PKDL) and visceral leishmaniasis-associated hemophagocytic lymphohistiocytosis-mimic (VL-associated HLH-mimic) further contribute to the diversity of clinical manifestations. These clinical variations are intricately influenced by the complex interplay between the host's immune response and the parasite's escape mechanisms. This narrative review aims to elucidate the underlying immunological mechanisms associated with each clinical manifestation, drawing from published literature within the last 5 years. Specific attention is directed toward viscerotropic Leishmania sinfection in patients with inborn errors of immunity and acquired immunodeficiencies. In VL, parasites exploit various immune evasion mechanisms, including immune checkpoints, leading to a predominantly anti-inflammatory environment that favors parasite survival. Conversely, nearly 70% of individuals are capable of mounting an effective pro-inflammatory immune response, forming granulomas that contain the parasites. Despite this, some patients may experience reactivation of the disease upon immunosuppression, challenging current understandings of parasite eradication. Individuals living with HIV and those with inborn errors of immunity present a more severe course of infection, often with higher relapse rates. Therefore, it is crucial to exclude both primary and acquired immune deficiencies in patients presenting disease relapse and VL-associated HLH-mimic. The distinction between VL and HLH can be challenging due to clinical similarities, suggesting that the nosological entity known as VL-associated HLH may represent a severe presentation of symptomatic VL and it should be considered more accurate referring to this condition as VL-associated HLH-mimic. Consequently, excluding VL in patients presenting with HLH is essential, as appropriate antimicrobial therapy can reverse immune dysregulation. A comprehensive understanding of the immune-host interaction underlying Leishmania infection is crucial for formulating effective treatment and preventive strategies to mitigate the disease burden.

Assessment of High-Resolution Melting Curve Analysis for Leishmania spp. Detection in Different Clinical Manifestations of Leishmaniasis in India.

The accurate diagnosis and identification of Leishmania species are crucial for the therapeutic selection and effective treatment of leishmaniasis. This study aims to develop and evaluate the use of high-resolution melting curve analysis (HRM)-PCR for Leishmania species identification causing visceral leishmaniasis (VL), post-kala-azar dermal leishmaniasis (PKDL) and cutaneous leishmaniasis (CL) in the Indian subcontinent. Two multi-copy targets (ITS-1 and 7SL-RNA genes) were selected, and an HRM-PCR assay was established using L. donovani, L. major, and L. tropica standard strain DNA. The assay was applied on 93 clinical samples with confirmed Leishmania infection, including VL (n = 30), PKDL (n = 50), and CL (n = 13) cases. The ITS-1 HRM-PCR assay detected as little as 0.01 pg of template DNA for L. major and up to 0.1 pg for L. donovani and L. tropica. The detection limit for the 7SL-RNA HRM-PCR was 1 pg for L. major and 10 pg for L. donovani and L. tropica. The ITS-1 HRM-PCR identified 68 out of 93 (73.11%) leishmaniasis cases, whereas 7SL-RNA HRM-PCR could only detect 18 out of 93 (19.35%) cases. A significant correlation was observed between the kDNA-based low Ct values and ITS-1 HRM-PCR positivity in the VL (p = 0.007), PKDL (p = 0.0002), and CL (p = 0.03) samples. The ITS-1 HRM-PCR assay could identify Leishmania spp. causing different clinical forms of leishmaniasis in the Indian subcontinent, providing rapid and accurate results that can guide clinical management and treatment decisions.

Combination Therapy for Post-Kala-Azar Dermal Leishmaniasis: A Literature Review of Current Evidence

Abstract Post-kala-azar dermal leishmaniasis (PKDL) is a neglected skin disease that has tremendous epidemiological significance as a reservoir of Leishmania parasites. Relapse, drug resistance, non-compliance to prolonged treatment, poor health-seeking behaviour, along with limited therapeutic options pose a significant impact on the management of PKDL. In this study, we aimed to review the efficacy, safety and tolerability data of combination therapies for PKDL in the published literature. We have also described patients’ compliance with treatment and associated co-infections in PKDL. A comprehensive literature search was conducted in PubMed, Scopus and Google Scholar to identify the relevant articles. A total of nine studies were eligible for inclusion in this review. Drug combinations used in India were miltefosine-liposomal amphotericin-B, miltefosine-paromomycin, miltefosine-amphotericin-B, sodium stibogluconate (SSG)-immunotherapy and SSG-rifampicin. However, in Sudan, except one, all studies have used SSG-based combinations viz. SSG-rifampicin, SSG-paromomycin and SSG-immunotherapy. The efficacy and safety of miltefosine in combination with liposomal amphotericin-B as well as conventional amphotericin-B were found to be excellent in a limited number of patients. These combinations are said to have better patient compliance and shorter treatment duration. Another combination of miltefosine and paromomycin was found to be satisfactory with a final cure rate of 83.3%. SSG in combination with paromomycin had a good clinical outcome among severe PKDL patients in Sudan, though pain at the injection site was experienced by all patients. There is a lack of data on combination therapies for PKDL through large-scale randomised controlled trials (RCTs). Therefore, multicentric randomized controlled trials with a sufficiently large sample size are urgently needed to verify the efficacy, safety, and other advantages of combination therapies for PKDL. With the availability of liposomal amphotericin-B, miltefosine and immunotherapy, clinical management of PKDL appears promising.

VL-HIV co-infection with Leishmania containing skin lesions resembling para-kala-azar dermal leishmaniasis.

Leishmaniases are a group of neglected vector-borne infectious diseases that are among the six priority endemic diseases worldwide. Visceral leishmaniasis (VL) is the most severe clinical manifestation, characterized by systemic and chronic visceral involvement and high mortality in immunosuppressed and untreated patients. VL can be complicated into post-kala-azar dermal leishmaniasis (PKDL), and when dermatologic disorders occur simultaneously with active VL, an intermediate clinical form called para-kala-azar dermal leishmaniasis (para-KDL) occurs. This clinical form is of great epidemiological relevance, as humans act as a source of infection for vectorial transmission. In the Americas, Brazil is among the seven countries responsible for more than 90% of VL cases, though reports of PKDL and para-KDL are rare. This paper presents three cases of VL-HIV co-infection with Leishmania-containing skin lesions resembling para-kala-azar dermal leishmaniasis. The cases were investigated by the team from the Infectious Diseases Department of University Hospital (HUMAP/UFMS) in Mato Grosso do Sul, Brazil. The three patients exhibited skin lesions where amastigote forms of L. (L.) infantum were identified. All cases exhibited similar clinical manifestations of para-KDL, including fever, hepatosplenomegaly, pancytopenia, and disseminated skin lesions. The study described the prevalence of comorbidities, the incidence of VL relapse, and the therapeutic regimen in relation to the outcomes. The study underscores the importance of follow-up and secondary prophylaxis in patients with VL, which are essential for the efficacy of the treatment. Furthermore, the study provides insight into the potential epidemiological profile of para-KDL cases in Brazil, which contributes to the development of more efficient clinical management strategies for patients.

Post kala-azar dermal leishmaniasis burden at the village level in selected high visceral leishmaniasis endemic upazilas in Bangladesh

ObjectivesAs post kala-azar Dermal Leishmaniasis (PKDL) threatens the success of the Visceral Leishmaniasis (VL) elimination initiative, we aimed to investigate the PKDL burden, including an active search for PKDL in leprosy-negative skin lesion cases. We also investigated their health-seeking behavior and perceived level of stigma. MethodsThis was a cross-sectional survey among inhabitants in the VL-endemic villages of the five most VL-endemic upazilas. VL experts trained medical officers in Upazila Health Complexes (UHCs) and leprosy facilities in PKDL management. Frontline workers conducted house-to-house surveys, referring PKDL suspects to designated centers. Data analysis involved Epi Info version 7 and IBM SPSS Statistics 25. ResultsAmong 472,435 screened individuals, 4022 had past VL (0.85 %). Among the screened population, 82 were PKDL suspects, and 62 PKDL cases were confirmed. The overall PKDL burden was 1.3 (95 % CI: 1.0-1.7) in the 10,000 population in the endemic villages. Male predominance and macular form of PKDL were observed. Thirty-nine PKDL patients perceived stigma of different levels. Only 27 of 62 (44 %) had received PKDL treatment. Medicine's unavailability and side effects were a major reason behind treatment interruption. Active screening among 137 leprosy-negative PKDL suspects yielded 10 (7.3 %) PKDL cases. ConclusionThe existence of PKDL cases in the VL endemic areas is a concern as those are inter-epidemic reservoirs. As per the WHO roadmap, the PKDL burden must be reduced by 70 % and 100 %, respectively, by 2026 and 2030. NKEP can take the current burden of 1.3 per 10,000 people in VL endemic villages as a baseline. Integrating active case detection for PKDL in leprosy hospitals and screening centers is feasible and worth deploying nationwide.

Disease-specific differences in pharmacokinetics of paromomycin and miltefosine between post-kala-azar dermal leishmaniasis and visceral leishmaniasis patients in eastern Africa.

Treatment regimens for post-kala-azar dermal leishmaniasis (PKDL) are usually extrapolated from those for visceral leishmaniasis (VL), but drug pharmacokinetics (PK) can differ due to disease-specific variations in absorption, distribution, and elimination. This study characterized PK differences in paromomycin and miltefosine between 109 PKDL and 264 VL patients from eastern Africa. VL patients showed 0.55-fold (95%CI: 0.41-0.74) lower capacity for paromomycin saturable reabsorption in renal tubules, and required a 1.44-fold (1.23-1.71) adjustment when relating renal clearance to creatinine-based eGFR. Miltefosine bioavailability in VL patients was lowered by 69% (62-76) at treatment start. Comparing PKDL to VL patients on the same regimen, paromomycin plasma exposures were 0.74-0.87-fold, while miltefosine exposure until the end of treatment day was 1.4-fold. These pronounced PK differences between PKDL and VL patients in eastern Africa highlight the challenges of directly extrapolating dosing regimens from one leishmaniasis presentation to another.

A randomized, double-blind phase 2b trial to evaluate efficacy of ChAd63-KH for treatment of post kala-azar dermal leishmaniasis

In a recent Phase IIa clinical trial, the candidate leishmaniasis vaccine ChAd63-KH was shown to be safe and immunogenic in Sudanese patients with post kala- azar dermal leishmaniasis. However, its value as a stand-alone therapeutic was unknown. To assess the therapeutic efficacy of ChAd63-KH, we conducted a randomized, double-blind, placebo-controlled Phase IIb trial (Clinicaltrials.gov registration: NCT03969134). Primary outcomes were safety and efficacy (≥90% improvement in clinical disease). Secondary outcomes were change in severity grade and vaccine-induced immune response. 86 participants with uncomplicated post kala azar dermal leishmaniasis of ≥ six months duration were randomised to receive ChAd63-KH (7.5x1010 viral particles once i.m.) or placebo. 75 participants (87%) completed the trial as per protocol. No severe or serious adverse events were observed. At day 90 post vaccination, 6/40 (15%) and 4/35 (11%) participants in the vaccine and placebo groups respectively showed ≥ 90% clinical improvement (RR 1.31 [95% CI, 0.40 to 4.28], p=0.742). There were also no significant differences in PKDL severity grade between study arms. Whole blood transcriptomic analysis identified transcriptional modules associated with interferon responses and monocyte and dendritic cell activation. Thus, a single vaccination with ChAd63-KH showed no therapeutic efficacy in this subset of Sudanese PKDL patients.

An Adult Male with Multiple Skin Lesions

Leishmaniasis, caused by Leishmania spp. and transmitted by infected female phlebotomine sandflies, manifests in various forms. These include visceral, cutaneous, and post-kala-azar dermal leishmaniasis (PKDL). The World Health Organisation (WHO) has officially validated Bangladesh as the first country to eliminate visceral leishmaniasis. However, sustaining this achievement is challenging if PKDL cases remain unchecked because PKDL patients act as human reservoirs. Here, we depict a case of PKDL with mixed skin lesions involving the face and multiple body parts. We hope this will raise a concern among us to be vigilant for such cases and maintain the success of eliminating visceral leishmaniasis. J MEDICINE 2024; 25: 191-192

Differences in the Cellular Immune Response during and after Treatment of Sudanese Patients with Post-kala-azar Dermal Leishmaniasis, and Possible Implications for Outcome

BackgroundThe host cellular immune response associated with two treatments for post-kala-azar dermal leishmaniasis (PKDL) - paromomycin plus miltefosine (Arm 1), and liposomal amphotericin B plus miltefosine (Arm 2) - was examined in Sudanese patients before treatment (D0), at the end of treatment (D42), and during the post-treatment period (D180).MethodsWhole blood samples were stimulated with soluble Leishmania antigen for 24 h (whole blood assay [WBA]) and the concentrations of Th1/Th2/Th17-associated cytokines, IP-10, PDL-1 and granzyme B were determined.ResultsThe Arm 1 treatment (98.2% cure rate) induced a Th1/Th2/Th17 response, while the Arm 2 treatment (80% cure rate) induced a Th1/Th2 response. Five Arm 2 patients relapsed and showed lower IFN-γ, TNF and IL-1β concentrations at D0 than non-relapsers in this Arm. In patients with low-IFN-γ-production at D0, Arm 1 treatment led to a better host immune response and clinical outcome than Arm 2 treatment.ConclusionsA Th1/Th2/Th17 response was associated with a higher cure rate. Patients with low IFN-γ, TNF and IL-1β before treatment are more likely to relapse if they undergo Arm 2-type treatment. Determining IFN-γ, TNF and IL-10 levels prior to treatment could help predict patients at higher risk of relapse/recovery from PKDL.Trial RegistrationClinicalTrials.gov NCT03399955, Registered 17 January 2018, https://clinicaltrials.gov/study/ NCT03399955.Graphical

Amphotericin B Deoxycholate Treatment of Post-Kala-Azar Dermal Leishmaniasis in India.

Post-kala-azar dermal leishmaniasis (PKDL) is widely prevalent in the endemic regions of India, but its treatment remains unsatisfactory. The WHO recommends a 12-week treatment with oral miltefosine, but its ocular toxicities are a serious concern. The late 1980s and early 1990s saw the use of sodium stibogluconate and amphotericin B (AmB) for a brief period. Both drugs had frequent adverse events and were expensive, and the duration of treatments was unacceptably long. This retrospective study evaluated, analyzed, and reported the outcomes of PKDL patients treated with a shorter course of AmB, the most effective antileishmanial drug. The hospital records of PKDL patients treated with AmB by 30 alternate-day infusions over 60 days (instead of conventional 60-80 infusions over 100-120 days) between September 2010 and August 2016 were reviewed. Only patients with confirmed parasitological diagnosis were included. Their records were studied for treatment-related adverse events, end-of-treatment parasitological status, and 12-month follow-up results. One hundred two patients were eligible for this study between September 2010 and August 2016. After therapy, 92/102 (90.2%) patients improved; 3 (2.9%) had to cease treatment owing to severe adverse effects, and one died of severe diarrhea unrelated to AmB. Six (5.9%) patients withdrew consent before the treatment was complete. At the 12-month evaluation, 89/102 (87.3%) patients attained a final cure. A 30-infusion regimen of AmB remains highly effective in PKDL. Without a shorter, safer, and more economical regimen for the treatment of PKDL, it should be used until a better regimen is available.

Visceral leishmaniasis follow-up and treatment outcomes in Tiaty East and West sub-counties, Kenya: Cure, relapse, and Post Kala-azar Dermal Leishmaniasis.

Visceral Leishmaniasis (VL) is a neglected tropical disease (NTD) with the highest regional burden in East Africa. Relapse and Post Kala-azar Dermal Leishmaniasis (PKDL) contribute to the spread of VL in endemic areas, making their surveillance imperative for control and elimination. Little is known about long-term patient outcomes in Kenya through follow-up after VL treatment, despite its requirement for control and elimination by the World Health Organization (WHO) and the Kenya Ministry of Health (KMOH). 36 follow-up patients in Tiaty East and West, sub-counties, Kenya, and records from 248 patients at the regional Chemolingot Sub-county Hospital (CSCH) were analyzed separately using Fisher's Exact Tests, two-sample t-tests, and Welch's t-tests in R (Version 4.3.0). The study found a prevalence rate of 88.89% (n = 32) final cure, 5.56% (n = 2) relapse, and 5.56% (n = 2) PKDL in follow-up patients and 92.74% (n = 230) initial cure, 6.86% (n = 17) relapse, and 0.80% (n = 2) PKDL in overall CSCH patients. The mean lengths of time at which follow-up patients relapsed and developed PKDL were 4.5 and 17 months, respectively. Young age (p = 0.04, 95% CI 0.63-24.31), shorter length of time from initial treatment to follow-up (p = 0.002, 95% CI 1.03-∞), lower Hb level at primary treatment (p = 0.0002, 95% CI 1.23-3.24), and living in Tiaty East sub-county (p = 0.04, 95% CI 0.00-1.43) were significantly associated (p<0.05) with VL relapse in follow-up study patients. Female sex (p = 0.04, 95% CI 0.84-∞) and living in Tiaty East sub-county (p = 0.03, 95% CI 0.00-1.43) were significantly associated with PKDL in follow-up study patients. More research should be done on PKDL in Kenya with active follow-up to understand its true burden. These results on prevalence and risk factors for PKDL and relapse in Kenya should inform knowledge of patient outcomes and interventions in the region.

Active Community-Based Case Finding of Endemic Leishmaniasis in West Bengal, India

IntroductionThe ongoing visceral leishmaniasis (VL) elimination programme in India is targeting the elimination of the disease VL but not the pathogen. The persistence of hidden parasite pool may initiate a resurgence in suitable conditions. This study dealt with a novel approach to unearth such pathogen pool and their proper management to prevent the resurgence of VL.Materials and MethodsWe deployed a new approach for detection of pathogen pool by following up the VL and post kala-azar dermal leishmaniasis patients treated during the last 10 years along with mass sero-surveillance within a radius of 500 m of recently treated individuals.ResultsWe followed up 72.6% (3026/4168) previously treated VL and post kala-azar dermal leishmaniasis patients and diagnosed 42 (1.4%) new and 38 (1.3%) recurrent post kala-azar dermal leishmaniasis. We detected 93 asymptomatic leishmanial infection, 8 VL and 1 post kala-azar dermal leishmaniasis by mass sero-surveillance.ConclusionOur three-step process including mapping and follow-up of previously treated cases, mass surveillance within 500 m of radius of known cases, and 6 monthly follow-on clinical and serological screening of asymptomatic cases, enabled detection of previously undetected cases of post kala-azar dermal leishmaniasis and VL. Recurrent post kala-azar dermal leishmaniasis deserves special attention regarding their treatment guideline. Early diagnosis and effective treatment of all leishmaniasis cases will hasten pathogen elimination and prevent resurgence of VL. This may help the policymakers to develop appropriate strategy for elimination of pathogen to prevent resurgence of VL.

Evaluation of blood based quantitative PCR as a molecular diagnostic tool for post kala-azar dermal leishmaniasis (PKDL).

Post kala-azar dermal leishmaniasis (PKDL) is a consequential dermal manifestation of visceral leishmaniasis (VL), serving as a parasite reservoir. The traditional diagnostic approach, which requires an invasive skin biopsy is associated with inherent risks and necessitates skilled healthcare practitioners in sterile settings. There is a critical need for a rapid, less invasive method for Leishmania detection. The main objective of this study was to evaluate and compare the diagnostic efficacy of PCR and qPCR in detecting PKDL, utilizing both skin and blood samples and to assess the utility of blood samples for molecular diagnosis. 73 individuals exhibiting clinical symptoms of PKDL and who had tested positive for rK39 rapid diagnostic test (RDT) were enrolled in this study. For the diagnosis of PKDL, both PCR and real-time quantitative PCR (qPCR), employing SYBR Green and TaqMan assays, were performed on blood and skin matched samples. qPCR results using both TaqMan and SYBR Green assay, indicated higher parasite loads in the skin compared to blood, as evident by the Ct values. Importantly, when blood samples were used for PKDL diagnosis by qPCR, an encouraging sensitivity of 69.35% (TaqMan assay) and 79.36% (SYBR Green) were obtained, compared to 8.2% with conventional PCR. The findings of the study suggest the potential utility of blood for molecular diagnosis by qPCR, offering a less invasive alternative to skin biopsies in field setting for the early detection of parasitaemia in PKDL patients and effective management and control of the disease.

A phase II, non-comparative randomised trial of two treatments involving liposomal amphotericin B and miltefosine for post-kala-azar dermal leishmaniasis in India and Bangladesh.

In Southeast Asia, treatment is recommended for all patients with post-kala-azar dermal leishmaniasis (PKDL). Adherence to the first-line regimen, twelve weeks of miltefosine (MF), is low and ocular toxicity has been observed with this exposure period. We assessed the safety and efficacy of two shorter-course treatments: liposomal amphotericin B (LAmB) alone and combined with MF. An open-label, phase II, randomized, parallel-arm, non-comparative trial was conducted in patients with parasitologically confirmed PKDL, 6 to ≤60 years. Patients were assigned to 20 mg/kg LAmB (total dose, in five injections over 15 days) alone or combined with allometric MF (3 weeks). The primary endpoint was definitive cure at 12 months, defined as complete resolution of papular and nodular lesions and >80% re-pigmentation of macular lesions. Definitive cure at 24 months was a secondary efficacy endpoint. 118/126 patients completed the trial. Definitive cure at 12 months was observed in 29% (18/63) patients receiving LAmB and 30% (19/63) receiving LAmB/MF (mITT), increasing to 58% and 66%, respectively, at 24 months. Most lesions had resolved/improved at 12 and 24 months for patients receiving LAmB (90%, 83%) and LAmB/MF (85%, 88%) by qualitative assessment. One death, unrelated to study drugs, was reported; no study drug-related serious adverse events were observed. The most frequent adverse drug reactions were MF-related vomiting and nausea, and LAmB-related hypokalaemia and infusion reactions. Most adverse events were mild; no ocular adverse events occurred. Both regimens are suitably safe and efficacious alternatives to long-course MF for PKDL in South Asia. CTRI/2017/04/008421.

Skin pharmacokinetics of miltefosine in the treatment of post-kala-azar dermal leishmaniasis in South Asia.

Post-kala-azar dermal leishmaniasis (PKDL) arises as a dermal complication following a visceral leishmaniasis (VL) infection. Current treatment options for PKDL are unsatisfactory, and there is a knowledge gap regarding the distribution of antileishmanial compounds within human skin. The present study investigated the skin distribution of miltefosine in PKDL patients, with the aim to improve the understanding of the pharmacokinetics at the skin target site in PKDL. Fifty-two PKDL patients underwent treatment with liposomal amphotericin B (20 mg/kg) plus miltefosine (allometric dosing) for 21 days. Plasma concentrations of miltefosine were measured on study days 8, 15, 22 and 30, while a punch skin biopsy was taken on day 22. A physiologically based pharmacokinetic (PBPK) model was developed to evaluate the distribution of miltefosine into the skin. Following the allometric weight-based dosing regimen, median miltefosine concentrations on day 22 were 43.73 µg/g (IQR: 21.94-60.65 µg/g) in skin and 33.29 µg/mL (IQR: 25.9-42.58 µg/mL) in plasma. The median individual concentration ratio of skin to plasma was 1.19 (IQR: 0.79-1.9). In 87% (45/52) of patients, skin exposure was above the suggested EC90 PK target of 10.6 mg/L associated with in vitro susceptibility. Simulations indicated that the residence time of miltefosine in the skin would be more than 2-fold longer than in plasma, estimated by a mean residence time of 604 versus 266 hours, respectively. This study provides the first accurate measurements of miltefosine penetration into the skin, demonstrating substantial exposure and prolonged retention of miltefosine within the skin. These findings support the use of miltefosine in cutaneous manifestations of leishmaniasis. In combination with parasitological and clinical data, these results are critical for the future optimization of combination therapies with miltefosine in the treatment of PKDL.

Antimony susceptible Leishmania donovani: evidence from in vitro drug susceptibility of parasites isolated from patients of post-kala-azar dermal leishmaniasis in pre- and post-miltefosine era.

Post-kala-azar dermal leishmaniasis (PKDL) patients, a key source of Leishmania donovani parasites, hinder eliminating visceral-leishmaniasis. Assessment of the susceptibility of PKDL isolates to antimony, miltefosine (MIL), and amphotericin-B indicated that recent isolates remain susceptible to antimony, enabling its use with other drugs for treating PKDL.