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Background: Localized cutaneous leishmaniasis (LCL) is a chronic ulcerating disease. A literature review identified inconsistencies in clinical trials. The aims of this study were to reach a consensus on the most important domains to measure when assessing LCL, agree on parameters to measure the domains, and develop a tool representing a Core Outcome Set (COS), for use in clinical assessment of LCL. Methodology & principal findings: A literature review was conducted to identify any existing COS for LCL embracing agreed Outcome Domains, i.e. what to measure and any Outcome Measurement Instruments (OMIs). As no COS was available, potential outcome domains for assessment of LCL were identified through an international collaborative approach using e-consultations and virtual discussions with expert stakeholders (n = 20) from geographically different LCL endemic countries. Subsequent judgmental validation process included a face-to-face multidisciplinary stakeholders' meeting adopting the Nominal Group Technique. A final consensual agreement on outcome domains and items required to measure these domains was established. "Clinical Cure" was defined as the ideal overall "General Concept". The five Core Outcome Domains included Signs capturing clinical morphology, diameter, and induration of an index lesion with the aid of a palpability score, Treatment Efficacy assessing percentage change in size of the lesion and re-epithelialization compared to baseline, Treatment Impact which included an investigator and patient visual analogue score, and Clinical Sequelae rating pigment change, atrophic and hypertrophic/keloid scars. It was agreed that two open-ended questions should be included to capture some aspects of Health-Related Quality of Life as a means of capturing a patient-focused approach. Conclusion: LeishCOM_LCL was generated to reflect a COS for LCL. This captured demographic details, agreed outcome domains and measures to assess these domains. Validation of LeishCOM_LCL will be reported in a separate paper. Development of a Patient Reported Outcome Measure will be considered in the future. Author summary: Localized cutaneous leishmaniasis (LCL) is a chronic ulcerating disease caused by the parasite Leishmania spp. Literature review identified inconsistencies in methods and parameters used to evaluate treatment/alternative-interventions resulting in difficulties in comparing new treatment/interventions in clinical trials. In our international consensual study, we adopted the face-to-face nominal group technique and a judgment process to identify domains key to assessment of LCL. Subsequent measures for each domain were used to form a Core Outcome Set (COS). LeishCOM_LCL was developed as an outcome measure instrument (OMI) to capture the COS incorporating existing and newly developed tools. "Clinical Cure" was agreed as the "General Concept" to be captured through five domains. It was agreed that "Signs" domain should capture clinical morphology, diameter, and induration of an index lesion with the aid of a palpability score. "Treatment Efficacy" was assessed by recording percentage change in size of the lesion and re-epithelialization compared to baseline. "Treatment Impact" was reflected through an investigator and the patient visual analogue score and "Clinical Sequelae" rated pigment change, atrophic/hypertrophic scars. Two open-ended questions were included to capture some aspects of "Health-Related Quality of Life". LeishCOM_LCL also records patient demographic details and was validated in a small cohort of patients. [ABSTRACT FROM AUTHOR]

Background: During infections involving intracellular pathogens, iron performs a double-edged function by providing the pathogen with nutrients, but also boosts the host's antimicrobial arsenal. Although the role of iron has been described in visceral leishmaniasis, information regarding its status in the dermal sequel, Post Kala-azar Dermal Leishmaniasis (PKDL) remains limited. Accordingly, this study aimed to establish the status of iron within monocytes/macrophages of PKDL cases. Methodology/Principal findings: The intramonocytic labile iron pool (LIP), status of CD163 (hemoglobin-haptoglobin scavenging receptor) and CD71 (transferrin receptor, Tfr) were evaluated within CD14+ monocytes by flow cytometry, and soluble CD163 by ELISA. At the lesional sites, Fe3+ status was evaluated by Prussian blue staining, parasite load by qPCR, while the mRNA expression of Tfr (TfR1/CD71), CD163, divalent metal transporter-1 (DMT-1), Lipocalin-2 (Lcn-2), Heme-oxygenase-1 (HO-1), Ferritin, Natural resistance-associated macrophage protein (NRAMP-1) and Ferroportin (Fpn-1) was evaluated by droplet digital PCR. Circulating monocytes demonstrated elevated levels of CD71, CD163 and soluble CD163, which corroborated with an enhanced lesional mRNA expression of TfR, CD163, DMT1 and Lcn-2. Additionally, the LIP was raised along with an elevated mRNA expression of ferritin and HO-1, as also iron exporters NRAMP-1 and Fpn-1. Conclusions/Significance: In monocytes/macrophages of PKDL cases, enhancement of the iron influx gateways (TfR, CD163, DMT-1 and Lcn-2) possibly accounted for the enhanced LIP. However, enhancement of the iron exporters (NRAMP-1 and Fpn-1) defied the classical Ferritinlow/Ferroportinhigh phenotype of alternatively activated macrophages. The creation of such a pro-parasitic environment suggests incorporation of chemotherapeutic strategies wherein the availability of iron to the parasite can be restricted. Author summary: Post kala-azar dermal leishmaniasis (PKDL), a dermal sequel of Visceral Leishmaniasis (VL) is caused by the digenetic protozoan parasite Leishmania donovani. The parasite infects humans and replicates intracellularly within macrophages, cells normally engaged in protecting the host from pathogens. Iron plays a crucial role in microbes and mammalian cells, being needed by the former for its growth and survival, while the latter uses it for activation of the immune system by facilitating generation of reactive oxygen species. Therefore, the availability of iron needs to be tightly regulated to ensure its accessibility for core biological functions, and yet prevent its utilization by intracellular pathogens. Here we investigated the status of intra-macrophage iron along with expression of its transporters in patients with PKDL. Our study suggests that within monocytes/macrophages there is an enhanced entry of iron via the upregulation of CD71 and CD163 that translates into an enhanced labile iron pool and Ferritin. However, the concomitant increase in expression of iron exporters NRAMP-1 and Fpn-1 suggested the host's attempt to deny the pathogen access to iron. This Ferritinhigh/Ferroportinhigh phenotype was in contrast to the conventional Ferritinlow/Ferroportinhigh phenotype present in alternatively activated M2 macrophages. Taken together, the control of iron homeostasis is one of the contributors in the host-pathogen interplay as it influences the course of an infectious disease by favouring either the mammalian host or the invading pathogen. [ABSTRACT FROM AUTHOR]

Abstract: The high level of functional diversity and plasticity in monocytes/macrophages has been defined within in vitro systems as M1 (classically activated), M2 (alternatively activated) and deactivated macrophages, of which the latter two subtypes are associated with suppression of cell mediated immunity, that confers susceptibility to intracellular infection. Although the Leishmania parasite modulates macrophage functions to ensure its survival, what remains an unanswered yet pertinent question is whether these macrophages are deactivated or alternatively activated. This study aimed to characterize the functional plasticity and polarization of monocytes/macrophages and delineate their importance in the immunopathogenesis of Post kala-azar dermal leishmaniasis (PKDL), a chronic dermatosis of human leishmaniasis. Monocytes from PKDL patients showed a decreased expression of TLR-2/4, along with an attenuated generation of reactive oxidative/nitrosative species. At disease presentation, an increased mRNA expression of classical M2 markers CD206, ARG1 and PPARG in monocytes and lesional macrophages indicated M2 polarization of macrophages which was corroborated by increased expression of CD206 and arginase-1. Furthermore, altered vitamin D signaling was a key feature in PKDL, as disease presentation was associated with raised plasma levels of monohydroxylated vitamin D3 and vitamin D3- associated genes, features of M2 polarization. Taken together, in PKDL, monocyte/macrophage subsets appear to be alternatively activated, a phenotype that might sustain disease chronicity. Importantly, repolarization of these monocytes to M1 by antileishmanial drugs suggests that switching from M2 to M1 phenotype might represent a therapeutic opportunity, worthy of future pharmacological consideration. [ABSTRACT FROM AUTHOR]