Pharmacotherapeutic Options for Visceral Leishmaniasis—Current Scenario

Visceral leishmaniasis (VL) or Kala-azar is a protozoal disease, which was previously regarded as one of the most neglected tropical diseases. Management of this disease is quite difficult, because it is said to affect the poorest of the poor. Previously Sodium Stibogluconate (SSG) was regarded as the gold standard treatment for VL. But due to the increasing unresponsiveness, to this drug various other drugs were tried and are still being tried. Pentamidine is very toxic and has been discarded of late. Amphotericin B and its lipid formulations are very effective but require hospital admission and monitoring. Oral drugs like Miltefosine have already been launched. An amino glycoside Paromomycin and another oral drug Sitamaquine are in the pipe line. Interferon gamma has been used with discouraging results

Tuberous sclerosis with visceral leishmaniasis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Visceral leishmaniasis, a tropical infectious disease, is a major public health problem in India. Tuberous sclerosis, a congenital neuro-ectodermosis, is an uncommon disease which requires life long treatment.</p> <p>Case presentation</p> <p>A 15-year-old Indian patient, presented to the outpatient department of our institute with a high-grade fever for two months, splenomegaly and a history of generalized tonic-clonic convulsions since childhood. The clinical and laboratory findings suggested visceral leishmaniasis with tuberous sclerosis. The patient was treated with miltefosine and antiepileptics.</p> <p>Conclusion</p> <p>The patient responded well and in a follow up six months after presentation, she was found free of visceral leishmaniasis and seizures. Diagnosis and treatment of this rare combination of diseases is difficult.</p

Identification of Clinical Immunological Determinants in Asymptomatic VL and Post Kala-azar Dermal Leishmaniasis Patients

Background: Visceral Leishmaniasis (VL) caused by protozoa belonging to the genus Leishmania, usually have anthroponotic mode of transmission and is issue of great public health importance in Indian subcontinent. Asymptomatic cases of VL and PKDL are subject of keen interest to find their role in the transmission of VL in epidemic areas. We evaluated the immunological cytokine determinants expressed in most clinical suspects of asymptomatic VL and PKDL (IL-10, IFN-γ, and TNF-α). Methods: Eighty-four participants were included at RMRIMS, Patna, India in 2016-17 out of which 64 asymptomatic individual positive for rK-39, without sign and symptoms of VL; 15 PKDL patient’s with past history of VL and 5 endemic healthy subjects were recruited from VL endemic areas. DAT and quantitative assessment of plasma cytokines was determined from the blood samples collected in a plain and sodium-EDTA vacutainer respectively from the subjects. Results: The mean level of IL-10 in DATposLOW of asymptomatic VL and PKDL was significantly higher than endemic healthy (P<0.05). The cytokine polarization index (IFN-γ versus IL-10) was significantly low in PKDL cases compared with asymptomatic VL cases in DATposLOW titre (P<0.05). This index was low again but statistically not significant in PKDL than in asymptomatic VL when TNF-α was considered against IL-10. The ratio of IFN-γ: IL-10 and TNF-α: IL-10 was observed decreased both in asymptomatic VL and PKDL cases than in healthy from endemic areas. Conclusion: Collectively we surmise from our data that asymptomatic VL can also play an important role like PKDL in transmission of VL

Computational screening of Six Antigens for potential MHC class II restricted epitopes and evaluating its CD4+ T-Cell Responsiveness against Visceral Leishmaniasis

Visceral leishmaniasis is one of the most neglected tropical diseases for which no vaccine exists. In spite of extensive efforts, no successful vaccine is available against this dreadful infectious disease. To support the vaccine development, immunoinformatics approach was applied to search for potential MHC-classII restricted epitopes that can activate the immune cells. Initially, a total of 37 epitopes derived from six, stage dependent over expressed antigens were predicted, which were presented by at least 26 diverse MHC class II alleles including: DRB10101, DRB10301, DRB10401, DRB10404, DRB10405, DRB10701, DRB10802, DRB10901, DRB11101, DRB11302, DRB11501, DRB30101, DRB40101, DRB50101, DPA10103-DPB10401, DPA10103-DPB10201, DPA10201-DPB10101, DPA10103-DPB10301_DPB10401, DPA10301-DPB10402, DPA10201-DPB105021, DQA10102-DQB10602, DQA10401-DQB10402, DQA10501-QB10201, DQA10501-DQB10301, DQA10301-DQB10302 and DQA10101-DQB10501. Based on the population coverage analysis and HLA cross presentation ability, six epitopes namely, FDLFLFSNGAVVWWG (P1), YPVYPFLASNAALLN (P2), VYPFLASNAALLNLI (P3), LALLIMLYALIATQF (P4), LIMLYALIATQFSDD (P5), IMLYALIATQFSDDA (P6) were selected for further analysis. Stimulation with synthetic peptide alone or as a cocktail triggered the intracellular IFN-γ production. Moreover, specific IgG class of antibodies was detected in the serum of active VL cases against P1, P4, P and P6 in order to evaluate peptide effect on humoral immune response. Additionally, most of the peptides, except P2, were found to be non-inducer of CD4+ IL-10 against both active VL as well as treated VL subjects. Peptide immunogenicity was validated in BALB/c mice immunized with cocktail of synthetic peptide emulsified in complete Freund’s adjuvant/incomplete Freund’s adjuvant. The immunized splenocytes induced strong spleen cell proliferation upon parasite re-stimulation. Furthermore, an increased IFN-γ, IL-12, IL-17 and IL-22 production augmented with elevated NO synthesis is thought to be play a crucial role in macrophage activation. Moreover, a significantly reduced parasite load in immunized group indicates the potentiality of polytope driven vaccine candidate against Visceral leishmaniasis

Ectopic Expression of Leishmanial DNA Polymerase β in Escherichia coli Confers Survival Advantage against Ultraviolet Radiation

Leishmania donovani encounters oxidative environment in the host macrophage and expected to have robust DNA repair mechanisms. Base Excision Repair (BER), a predominant repair pathway in L. donovani remains unexplored. Presence of mitochondria in eukaryotes has been projected as a symbiotic relationship since long and the role of DNA polymerase β in repair of mitochondrial DNA has gained importance in recent past. We ectopically expressed Leishmania DNA polymerase β (LdPolβ) under inducible promoter in E. coli and found it is biologically active in vitro by using pUC19 as substrate. Further we checked its effect on sensitivity of E. coli to UV rays. We find that heterologous LdPolβ slows down the growth of E. coli and surprisingly, could protect it from lethal effects of UV to a large extent. Co-expression of leishmania DNA Ligase IIIα (LdLigIIIα) has a synergistic effect on survival advantage offered by LdPolβ. Survival advantage given LdPolβ in E. coli is reconfirmed by FACS analysis. Our observations indicate that LdPolβ is crucial for handling ROS induced toxicity inside the mitochondria of the parasite and for its survival inside host macrophage. This studied may lead to explore for finding of the importance of LdPolβ in survival against DNA damaging agents in L. donovani and its role in pathogenesis of leishmaniasis, it would help to discover new target and development of newer drug against Leishmaniasis

Knowledge, stigma, health seeking behaviour and its determinants among patients with post kalaazar dermal leishmaniasis, Bihar, India.

BACKGROUND:Lesishmaniasis is a neglected tropical disease endemic in Bihar, India. Inappropriate health seeking behaviour of post kala-azar dermal leishmaniasis (PKDL) patients may increase the disease duration, severity and transmissibility. Simultaneously, lack of knowledge and perceived stigma may also increase the length of delay in receiving treatment. This ultimately effects the kala-azar elimination program. METHODS:A cross sectional study was conducted in 120 confirmed PKDL patients, aged 18 years and older. Data related to knowledge and health seeking behaviour was collected by a pre-tested questionnaire. EMIC stigma scale was used for assessing the perceived stigma. Patients were personally interviewed after taking informed consent. Data analysis was done by using SPSS 16 software. RESULTS:The time between appearance of symptoms and first medical consultation (patient delay) ranged from 15 days to 5475 days (15 years) with a median of 285 days. The time between first medical consultations to onset of specific treatment (system delay) ranged from 2 to 5475 days with a median of 365 days. Many patients approached first to quacks (8.4%), homeopathic and ayurvedic practitioners (25.8%) upon recognition of symptoms. Majority of the patients (68.3%) had poor knowledge about PKDL and its vector. Type of skin lesions and gender had significant association with patient delay and system delay respectively (p<0.05). Distance to primary health centre (PHC) had significant association with patients delay as well as system delay (p<0.05). Patients with younger age, unmarried and polymorphic lesions had higher stigma (p<0.05). Patients with PKDL feel stigmatized in different areas. CONCLUSION:PKDL treatment delays were unacceptably high and patients had poor knowledge compounded with feelings of stigmatization. To reduce the delay, a system may be evolved to establish some sort of public-private collaboration, besides awareness programs should be tailored, and implemented for improving the patient education regarding the disease and its linkage with VL