Differential structure and immunomodulatory functions of lipophosphoglycan between Leishmania spp

Leishmaniasis is a collective term for several tropical, neglected diseases caused by protozoans of the species Leishmania, 20 of which causing disease in humans ranging from localised self-healing lesions to chronic manifestations which affect the skin or inner organs. Although millions of infections are accounted for annually, treatment options are scarce and limited to medication associated with heavy side-effects and increasing antibiotic resistance. Case studies point towards immunotherapy as effective alternative treatment relying on immunomodulatory properties of e.g., the Bacillus Calmette-Guérin vaccine. Leishmania parasites are also known to modulate the immune system, yet the underlying macromolecules and surface molecules remain widely under characterised. With this short review, we aim to provide a complete summary of the existing literature describing one of the most expressed surface molecule on Leishmania spp, lipophosphoglycan (LPG), which shows great variability between different lifecycle stages and different Leishmania spp. Complete characterisation of LPG may aid to improve treatment and aid the development of vaccination strategies, and open new avenues to exploit the immunomodulatory properties of LPG in unrelated conditions.

Visceral leishmaniasis-human immunodeficiency virus coinfection in a 52-year-old male in southwest Iran: a case report

BACKGROUND

Leishmaniasis is a rare infectious disease observed in subtropical and tropical areas. This disease that demonstrates different clinical characteristics is caused by intracellular Leishmania protozoan. One of the important countries facing the incidence of this infectious disease is Iran. Recently, human immunodeficiency virus-Leishmania coinfection has been indicated in Iran.

CASE PRESENTATION

In the present case report, we show an atypical case of severe visceral leishmaniasis in a 52-year-old Iranian-Arab male with positive human immunodeficiency virus status. Leishmaniasis was detected by node biopsy and subsequently histopathology evaluations and confirmed by molecular methods.

CONCLUSIONS

The current study was the first report of an atypical case of a patient with Leishmania-human immunodeficiency virus coinfection in southwestern Iran, which was not responsive to the treatment. Therefore, the health authorities should be aware of these reports, which require permanent clinical follow-up of the patients as well as effective treatments.

A Comprehensive Review on HIV-Associated Dermatologic Manifestations: From Epidemiology to Clinical Management

Dermatological disorders are among the most prevalent manifestations of HIV infection/acquired immunodeficiency syndrome (AIDS). In this review, we aimed to characterize the various dermatologic presentations among HIV-infected patients with a detailed categorization of the mucocutaneous signs and symptoms, their etiopathogenic factors, and clinical management. In fact, cutaneous manifestations of HIV are quite various, ranging from AIDS-specific skin eruptions (xerosis, pruritic papular eruptions, eosinophilic folliculitis, and acne), opportunistic infections (herpes simplex, molluscum contagiosum, cutaneous leishmaniasis, bacillary angiomatosis, disseminated histoplasmosis, disseminated cryptococcosis, and zoster) to AIDS-related malignancies (Kaposi's sarcoma, lymphoma, and nonmelanoma skin cancers) and antiretroviral therapy (ART)-associated drug eruptions. We tried to classify HIV-related cutaneous presentations which can help clinicians for a better understanding of the various specific and nonspecific features of AIDS-associated cutaneous manifestations and management of the condition.

Tissue tropism: Is it an intrinsic characteristic of Leishmania species?

The genus Leishmania comprises a wide range of species, some of which are pathogenic to humans and each of which has a different tissue preference, resulting in one of the three clinical forms of human leishmaniasis: visceral, cutaneous, or mucocutaneous. Although, all pathogenic species are deposited intradermally in the mammalian host upon an infectious sand fly bite, only the viscerotropic strains can leave the skin and reach the internal organs. We assume that Leishmania tissue tropism is not only the result of Leishmania genetic determinism but is also governed by the interaction of the parasite with different vectorial and human host elements. To shed light on these elements and key steps determining the course of the infection, we describe throughout this review the disease's progression from the early stages of infection taking place in the skin to the late stages succeeding in the parasite's visceral dissemination. Hence, we address the question of Leishmania tropism, through providing relevant hypotheses and answers gathered from the literature.

Molecular and serological evaluation of zoonotic visceral leishmaniasis in dogs in a rural area of Fars province, southern Iran, as a source of Leishmania infantum infection

Canine visceral leishmaniasis (CVL) is endemic in the southern parts of Iran. The current study aimed at molecular and serological evaluation of zoonotic visceral leishmaniasis in dogs in Fars province, southern Iran. Blood samples were collected from 60 dogs in the three villages in Fars Province. Serum samples were tested for antibodies against L. infantum by direct agglutination test (DAT). DNA was extracted from each dog's buffy coat and tested by PCR, targeting the Leishmania ITS‐2 region. From a total of 60 studied dogs, 25 (41.7%) were female, and 35 (58.3%) were male. Dogs' age ranged from 1 to 7 years, with a mean age of 2.97 (±1.4) years. Anti‐Leishmania antibodies were detected in sera samples of 28 (46.7%) dogs, (titre ≥ 1:320). Out of 28 seropositive cases, 13 (46.4%) were female, and 15 (53.6%) were male. Association between seropositivity and dogs’ clinical signs was statistically significant (p < .05). Leishmania DNA was detected in the buffy coat of 3 of 60 studied dogs which were all seropositive by DAT. The PCR products were sequenced and molecular analysis showed that two of the isolates were Leishmania infantum, and one was L. tropica. The high proportion of seropositive dogs indicates the important role of these animals in the epidemiology of the disease in the region. Infected dogs with or without signs, especially those that are molecularly positive, can act as an active reservoir of the disease in the area.

Unusual clinical presentation of cutaneous leishmaniasis in a patient with corticosteroid-induced immunosuppression

Clinicians should always consider rare, atypical, and opportunistic infections in patients undergoing long-term systemic corticosteroid therapy. Diagnosis needs further evaluations and special consideration.

First Serological Study Revealing High Humoral Response and Evidence for Antigenic Heterogeneity in Leishmania donovani Induced CL in Sri Lanka

Posing a threat to the ongoing leishmaniasis elimination efforts in the Indian subcontinent, L. donovani-induced cutaneous leishmaniasis (CL) has been recently reported in many countries. Sri Lanka reports a large focus of human cutaneous leishmaniasis (CL) caused by Leishmania donovani, a usually visceralizing parasite. Enhanced case detection, early treatment, and in-depth understanding of sequalae are required to contain the spread of disease. Visceralizing potential of dermotropic strains has not been fully ruled out. Sri Lankan strains have shown a poor response to established serological assays. The present concern was to develop an in-house serological assay and to determine the seroprevalence of CL for identifying visceralizing potential and its usefulness in enhancing case detection. Crude cell lysate of dermotropic L. donovani promastigotes-based indirect enzyme-linked immunosorbent assay (ELISA) was previously optimized. Assay was evaluated using sera from 200 CL patients, 50 endemic and 50 nonendemic healthy controls, 50 patients with other skin diseases, and 50 patients with other systemic diseases. Seroprevalence and clinicoepidemiological associations were analyzed. Assay was compared with light microscopy (LM) and in vitro culturing (IVC). Cost comparison was carried out. Seroprevalence of CL was 82.0%. The assay had 99.5% specificity, and all healthy controls were negative at 0.189 cut-off. Positive and negative predictive values were 99.4% and 84.7%, respectively. Positivity obtained in ELISA was comparable to LM and higher than that of IVC. Cost per patient was 3.0 USD for both ELISA and LM and 6.0 USD for IVC. Infections occurring in all age groups and both genders demonstrated >75.0% of seropositivity. Patients had lesions with different durations/types/sizes showed >70.0% of seropositivity. Study identified a high seroprevalence of L. donovani-induced CL for the first time, indicating potential for visceralization or transient serological response. This can be used as a second line test in LM-negative CL cases to enhance clinical case detection. Further studies are warranted to examine in-depth correlations, antigen profiles, comparison with other established serological tools, and usefulness in the detection of asymptomatic cases. (National patent LK/P/1/19697).

Population structures of Leishmania infantum and Leishmania tropica the causative agents of kala-azar in Southwest Iran

Visceral leishmaniasis (VL) is endemic in Iran and is caused predominantly by Leishmania infantum, but L. tropica is emerging as an important cause. We studied the intra-species population structure of Leishmania spp. causing VL in southwest Iran by sequence analysis of the internal transcribed spacer (ITS) 1 of DNA samples from 29 bone marrow aspiration smears. L. infantum (n = 25) and L. tropica (n = 4) were identified, consisting of 10 and three ITS1 sequence types (STs), respectively. Compared to GenBank ITS1 STs, our L. infantum parasites displayed high heterogeneity but less heterogeneity compared than northwest Iranian isolates. VL affects mostly nomadic populations in southwest Iran, and their mobility may explain partly the L. infantum heterogeneity. The VL causing L. tropica was also genetically heterogeneous but genetically indistinguishable from L. tropica strains causing anthroponotic cutaneous leishmaniasis from southwest Iran.

First case report of atypical disseminated cutaneous leishmaniasis in an opium abuser in Iran

Leishmaniasis is a worldwide tropical infectious disease caused by different species of intracellular protozoa parasites of the genus Leishmania . Herein, we report a 78-year-old man with unusual diffuse cutaneous leishmaniasis (DCL) who had a history of opium abuse and chronic obstructive pulmonary disease (COPD). He had multiple papular, crusted and severely ulcerated lesions extended to his arm and chest. Direct smears and skin punch biopsy of the lesions were suggestive of leishmaniasis. Parasite DNA was amplified from ulcers, and identified as Leishmania major by PCR-RFLP, confirmed by sequencing analyses. The aim of the current study was to bring to attention this atypical form of disease in CL endemic countries. Thus, this is the first case of DCL in an opium abuser with COPD due to L. major in Northeastern Iran indicating that atypical and extensive forms of CL (DCL) owing to L. major are increasing in Iran.

Case Report: First Coinfection Report of Mixed Leishmania infantum/Leishmania major and Human Immunodeficiency Virus-Acquired Immune Deficiency Syndrome: Report of a Case of Disseminated Cutaneous Leishmaniasis in Iran

Visceral leishmaniasis, a neglected tropical disease, is the third most common opportunistic disease in immunosuppressed patients, such as those affected by the human immunodeficiency virus (HIV)/acquired immune deficiency syndrome. Although the reports have been characterized as Leishmania/HIV coinfections, the occurrence of a mixed infection by two Leishmania species in HIV-positive patients is rare. Here, we present an atypical case of disseminated cutaneous leishmaniasis (DCL) in a 26-year-old HIV-positive man. The diagnosis of DCL was established using skin biopsy and histopathology examinations and confirmed by molecular techniques. This is the first case of a Leishmania/HIV coinfection due to a mixed infection of Leishmania infantum/Leishmania major in Iran.

Atypical presentations of cutaneous leishmaniasis: A systematic review

Cutaneous Leishmaniasis (CL) is endemic in 88 countries, showing relevant prevalences. The aim of this study was to perform a systematic review on atypical lesions of CL around the world, addressing clinico-epidemiological, immunological and therapeutic aspects. A search of the literature was conducted via electronic databases Scopus and PubMed for articles published between 2010 and 2015. The search terms browsed were "cutaneous leishmaniasis", "atypical" and "unusual". Based on the eligibility criteria, 34 out of 122 articles were included in the final sample. Atypical lesions may include the following forms: erythematous volcanic ulcer, lupoid, eczematous, erysipeloid, verrucous, dry, zosteriform, paronychial, sporotrichoid, chancriform and annular. In any cases, they seem to be another disease like subcutaneous and deep mycosis, cutaneous lymphoma, pseudolymphoma, basal and squamous cell carcinoma. The lesions have been reported in the face, cheeks, ears, nose, eyelid, limbs, trunk, buttocks, as well as in palmoplantar and genital regions; sometimes occurring in more than one area. The reason for clinical cutaneous leishmaniasis pleomorphism is unclear but immunosuppression seems to play an important role in some cases. There are no established guidelines for the treatment of atypical cutaneous leishmaniasis. However, pentavalent antimonials remain as first line treatment for all forms of leishmaniasis even for HIV-infected patients and atpical forms. Finally, to diagnose an atypical lesion properly, the focus has to be on the medical history and the origin of the patient, comparing them to the natural history of leishmaniasis and always reminding of possible atypical presentations, to then start searching for the best diagnostic method and treatment, reducing the misdiagnosis rate and, subsequently, controlling the disease progression. Thereby, contributing for breaking the transmission chain of the parasite, due to early correct diagnosis which, in turn, contributes to reduce the prevalence.

Presentation of AIDS with Disseminated Cutaneous and Visceral Leishmaniasis in Iran

Leishmaniasis is an infectious disease in form of visceral (VL), cutaneous (CL), and mucocutaneous (MCL) leishmaniasis. Immunocompromised patients have increased risk of Leishmania infection, especially in endemic areas for visceral leishmaniasis, where in the world HIV/VL coinfection has become endemic. The case here suffers from both AIDS and visceral-cutaneous leishmaniasis. We report an Iranian woman with disseminated cutaneous and visceral leishmaniasis who became positive for HIV test.

PKDL and other dermal lesions in HIV co-infected patients with Leishmaniasis: review of clinical presentation in relation to immune responses

Background

Co-infection of leishmaniasis and HIV is increasingly reported. The clinical presentation of leishmaniasis is determined by the host immune response to the parasite; as a consequence, this presentation will be influenced by HIV-induced immunosuppression. As leishmaniasis commonly affects the skin, increasing immunosuppression changes the clinical presentation, such as in post-kala-azar dermal leishmaniasis (PKDL) and cutaneous leishmaniasis (CL); dermal lesions are also commonly reported in visceral leishmaniasis (VL) and HIV co-infection.

Methods

We reviewed the literature with regard to dermal manifestations in leishmaniasis and HIV co-infection, in three clinical syndromes, according to the primary presentation: PKDL, VL, or CL.

Results

A wide variety of descriptions of dermal leishmaniasis in HIV co-infection has been reported. Lesions are commonly described as florid, symmetrical, non-ulcerating, nodular lesions with atypical distribution and numerous parasites. Pre-existing, unrelated dermal lesions may become parasitized. Parasites lose their tropism and no longer exclusively cause VL or CL. PKDL in HIV co-infected patients is more common and more severe and is not restricted to Leishmania donovani. In VL, dermal lesions occur in up to 18% of patients and may present as (severe) localized cutaneous leishmaniasis, disseminated cutaneous leishmaniasis (DL) or diffuse cutaneous leishmaniasis (DCL); there may be an overlap with para-kala-azar dermal leishmaniasis. In CL, dissemination in the skin may occur resembling DL or DCL; subsequent spread to the viscera may follow. Mucosal lesions are commonly found in VL or CL and HIV co-infection. Classical mucocutaneous leishmaniasis is more severe. Immune reconstitution disease (IRD) is uncommon in HIV co-infected patients with leishmaniasis on antiretroviral treatment (ART).

Conclusion

With increasing immunosuppression, the clinical syndromes of CL, VL, and PKDL become more severe and may overlap. These syndromes may be best described as VL with disseminated cutaneous lesions (before, during, or after VL) and disseminated cutaneous leishmaniasis with or without visceralization.

Identification and phylogenetic relationship of Iranian strains of various Leishmania species isolated from cutaneous and visceral cases of leishmaniasis based on N-acetylglucosamine-1-phosphate transferase gene

The identity of Iranian Leishmania species has been resolved to some extent by some genetic markers. In this study, based on N-acetylglucosamine-1-phosphate transferase (nagt) gene, we further elucidated the identity and phylogeny of the prevalent species in this country. DNAs of 121 isolates belonging to cutaneous leishmaniasis (CL) patients, canine visceral leishmaniasis (CVL) cases, and Rhombomys opimus rodents were amplified by targeting a partial sequence of nagt gene. All the amplicons were analyzed with restriction fragment length polymorphism (RFLP) using Acc1 enzyme, and 49 amplicons representing different reservoir hosts were sequenced and aligned with similar sequences from GenBank database. The RFLP analysis revealed that 41 CL patients were infected Leishmania tropica and 36 with Leishmania major. Among 10 CVL isolates, 6 were identified as Leishmania infantum and 4 as L. tropica. Amongst 34 rodents' isolates, 11 and 23 isolates exhibited patterns similar to those of L. major, and L. tropica/Leishmania turanica, respectively. The sequencing results from all CL patients, CVL cases, and 4 reservoir rodents were in agreement with RFLP analysis and showed 99-100% homologies with the registered species of L. major, L. tropica, and L. infantum from Turkey, Tunisia, Iraq and Israel. Of the 7 rodent isolates exhibiting RFLP patterns similar to L. tropica/L. turanica, 3 exhibited the highest homologies (99-100%) with L. turanica and 4 with Leishmania gerbilli. The 49 nagt DNA sequences were grouped into five clusters representing L. major, L. tropica, L. infantum, L. turanica and L. gerbilli species, encompassing 19 haplotypes. No correlation was observed between intraspecies divergence and geographic distribution of haplotypes. The L. tropica haplotypes exhibited more homologies with those of L. infantum than L. major (97.2% vs. 96.9%), a probable indication to the potential ability of L. tropica to visceralize. Characterization of Iranian Leishmania isolates using nagt gene allowed unambiguous identification of five prevalent species with a high-resolution phylogeny.

Molecular identification and polymorphism determination of cutaneous and visceral leishmaniasis agents isolated from human and animal hosts in Iran

Amplification of internal transcript spacer 1 of ribosomal RNA (ITS1-RNA) gene followed by RFLP analysis and sequencing was used to identify the causing agents of cutaneous and visceral leishmaniasis (CL and VL) in humans and animal reservoir hosts from various geographical areas in Iran. We also used random amplified polymorphic DNA (RAPD-PCR) to obtain polymorphisms among isolates of Leishmania spp. Totally, 362 suspected human and animal cases including 173 CL, 49 VL, 60 rodents, and 80 domestic dogs were examined for Leishmania infection. From 112 culture-positive samples prepared from CL cases, 75 (67%) were infected with L. major and 37 (33%) with L. tropica. Of the 60 rodents examined, 25 (41.6%) harbored the Leishmania infection; 21 were infected with L. major and 4 with L. turanica. From 49 suspected VL, 29 were positive by direct agglutination test (DAT), whereas microscopy detected parasite in bone marrow of 25 and culture in 28 of the patients. Two VL patients were infected with L. tropica and 26 with L. infantum. Of the 80 domestic dogs, 56 showed anti-Leishmania antibodies with DAT. Of these, 55 were positive by both microscopy and culture. Molecular identity, obtained only for 47 samples, revealed L. infantum in 43 and L. tropica in 4 dogs. The polymorphisms among L. tropica and L. major isolates were 3.6% and 7.3%; the rate among human and canine VL isolates was 2.8% and 9.8%, respectively. Our results showed that at least four different Leishmania species with various polymorphisms circulate among humans and animal hosts in Iran.

Identification of Leishmania tropica from micro-foci of cutaneous leishmaniasis in the Kenyan Rift Valley

We performed diagnosis and species identification of parasites in lesion samples from suspected cutaneous leishmaniasis patients in four villages, three of which are in a known Leishmania tropica endemic region in Kenya. Samples were analyzed both by microscopy and PCR for Leishmania, and typed by an assay using four ribosomal DNA-based species-identification PCRs. The lesions were demonstrated to be caused by L. tropica, which confirms the re-emergence of cutaneous leishmaniasis from this species after a period of reduced incidence in the endemic zone. Our report highlights the importance of an intervention and sustained Leishmania control program.

An observational study on the current distribution of visceral leishmaniasis in different geographical zones of Iran and implication to health policy

Visceral leishmaniasis is one of the most important parasitic diseases that is endemic in some parts of Iran. This study aimed to determine current distribution of visceral leishmaniasis in four distinct geographical zones of Iran. A cross-sectional study was conducted using direct agglutination test (DAT) on 9396 and 2559 serum samples collected from humans and domestic dogs, respectively during the period of 2007 through 2009. Altogether, 403 (4.3%) out of 9396 human serum samples collected from 4 distinct geographical locations showed anti-Leishmania antibodies with titers ≥ 1:3200. Physical examinations performed on 142 sero-positive cases with anti-Leishmania antibodies at titers of 1: 3200 to 1:102400 among whom fever (94.4%), paleness (67.6%) and hepato-splenomegaly (42.2%) were the predominant clinical signs and symptoms. The highest sero-prevalence rate (1.55%) was found in children ≤ 5 years old. Out of 2559 serum samples collected from domestic dogs, 212 (8.3%) were DAT positive (≥ 1:320). Leishmania infantum is the principal causative agent of the disease was isolated from both infected humans and dogs in Iran. Our findings indicate that Mediterranean visceral leishmaniasis with different distribution occurs in different geographical locations of Iran.