Medicine
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This repository contains the published and unpublished research of the Faculty of Medicine by the staff members of the faculty
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Item Proteome profiling of cutaneous leishmaniasis lesions due to dermotropic Leishmania donovani in Sri Lanka(BioMed Central, 2024) Manamperi, N.H.; Edirisinghe, N.M.; Wijesinghe, H.; Pathiraja, L.; Pathirana, N.; Wanasinghe, V.S.; De Silva, C.G.; Abeyewickreme, W.; Karunaweera, N.D.BACKGROUND Characterization of the host response in cutaneous leishmaniasis (CL) through proteome profiling has gained limited insights into leishmaniasis research compared to that of the parasite. The primary objective of this study was to comprehensively analyze the proteomic profile of the skin lesions tissues in patients with CL, by mass spectrometry, and subsequent validation of these findings through immunohistochemical methods.METHODS Eight lesion specimens from leishmaniasis-confirmed patients and eight control skin biopsies were processed for proteomic profiling by mass spectrometry. Formalin-fixed paraffin-embedded lesion specimens from thirty patients and six control skin specimens were used for Immunohistochemistry (IHC) staining. Statistical analyses were carried out using SPSS software. The chi-square test was used to assess the association between the degree of staining for each marker and the clinical and pathological features.RESULTS Sixty-seven proteins exhibited significant differential expression between tissues of CL lesions and healthy controls (p < 0.01), representing numerous enriched biological processes within the lesion tissue, as evident by both the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome databases. Among these, the integrated endoplasmic reticulum stress response (IERSR) emerges as a pathway characterized by the up-regulated proteins in CL tissues compared to healthy skin. Expression of endoplasmic reticulum (ER) stress sensors, inositol-requiring enzyme-1 (IRE1), protein kinase RNA-like ER kinase (PERK) and activating transcription factor 6 (ATF6) in lesion tissue was validated by immunohistochemistry.CONCLUSIONS In conclusion, proteomic profiling of skin lesions carried out as a discovery phase study revealed a multitude of probable immunological and pathological mechanisms operating in patients with CL in Sri Lanka, which needs to be further elaborated using more in-depth and targeted investigations. Further research exploring the intricate interplay between ER stress and CL pathophysiology may offer promising avenues for the development of novel diagnostic tools and therapeutic strategies in combating this disease.Item ELISA based evaluation of antibody response to Leishmania in a region endemic for cutaneous leishmaniasis(Oxford, 2022) Piyasiri, S.B.; Samaranayake, T.N.; Silva, H.; Manamperi, N.H.; Karunaweera, N.D.Aims: Leishmaniasis includes several clinical forms. While routine diagnosis of cutaneous leishmaniasis (CL) is by microscopy, an antibody response to CL has been reported in several recent studies. This study evaluated anti-leishmanial IgG antibody responses as a biomarker of active leishmaniasis and a measure of exposure to Leishmania. Methods and results: Sera from 50 untreated CL patients, 140 patients under treatment and 280 healthy individuals residing in endemic regions collected as part of an epidemiological survey, was analysed with an ELISA established in-house using receiver-operator-characteristic (ROC) curve at optimised cut-off value. The assay showed high performance as a diagnostic tool in identifying exposure in endemic individuals (sensitivity: 98%, specificity: 90.3%). All patients showed lower antibody levels over time since onset of lesion/s. Antibody levels were higher (p ˂ 0.01) and persisted for a longer period in untreated patients. In patients under treatment, the level of anti-IgG antibodies was negatively correlated with the total duration the patient had been on treatment. Conclusion: The anti-leishmanial IgG response in L. donovani induced CL is transient and is unlikely to confer protective immunity. Optimised serological assays may be useful in endemic settings for diagnosis and monitoring the treatment response in CL.Item Spatial epidemiologic trends and hotspots of leishmaniasis, Sri Lanka, 2001-2018(Centers for Disease Control and Prevention (CDC), 2020) Karunaweera, N.D.; Ginige, S.; Senanayake, S.; Silva, H.; Manamperi, N.; Samaranayake, N.; Siriwardana, Y.; Gamage, D.; Senerath, U.; Zhou, G.;ABSTRACT: Leishmaniasis, a neglected tropical disease, is on the decline in South Asia. However, cases of cutaneous leishmaniasis have risen in Sri Lanka since 2001, and the lack of in-depth research on its epidemiologic characteristics hampers control efforts. We analyzed data collected from patients with cutaneous leishmaniasis in Sri Lanka during 2001-2018 to study temporal and geographic trends and identify and monitor disease hotspots. We noted a progression in case rates, including a sharp rise in 2018, showing temporal expansion of disease-prevalent areas and 2 persistent hotspots. The northern hotspot shifted and shrank over time, but the southern hotspot progressively expanded and remained spatially static. In addition, we noted regional incidence differences for age and sex. We provide evidence of temporally progressive and spatially expanding incidence of leishmaniasis in Sri Lanka with distinct geographic patterns and disease hotspots, signaling an urgent need for effective disease control interventions. KEYWORDS: Asia; Indian subcontinent; Leishmania donovani; Sri Lanka; cutaneous leishmaniasis; dermatological pathologies; epidemiology; infectious diseases; leishmaniasis; parasites; protozoa; skin lesions; vector-borne infections.Item Spatiotemporal distribution of cutaneous leishmaniasis in Sri Lanka and future case burden estimates(Public Library of Science, 2021) Karunaweera, N.D.; Senanayake, S.; Ginige, S.; Silva, H.; Manamperi, N.; Samaranayake, N.; Dewasurendra, R.; Karunanayake, P.; Gamage, D.; de Silva, N.; Senarath, U.; Zhou, G.BACKGROUND: Leishmaniasis is a neglected tropical vector-borne disease, which is on the rise in Sri Lanka. Spatiotemporal and risk factor analyses are useful for understanding transmission dynamics, spatial clustering and predicting future disease distribution and trends to facilitate effective infection control. METHODS: The nationwide clinically confirmed cutaneous leishmaniasis and climatic data were collected from 2001 to 2019. Hierarchical clustering and spatiotemporal cross-correlation analysis were used to measure the region-wide and local (between neighboring districts) synchrony of transmission. A mixed spatiotemporal regression-autoregression model was built to study the effects of climatic, neighboring-district dispersal, and infection carryover variables on leishmaniasis dynamics and spatial distribution. Same model without climatic variables was used to predict the future distribution and trends of leishmaniasis cases in Sri Lanka. RESULTS: A total of 19,361 clinically confirmed leishmaniasis cases have been reported in Sri Lanka from 2001-2019. There were three phases identified: low-transmission phase (2001-2010), parasite population buildup phase (2011-2017), and outbreak phase (2018-2019). Spatially, the districts were divided into three groups based on similarity in temporal dynamics. The global mean correlation among district incidence dynamics was 0.30 (95% CI 0.25-0.35), and the localized mean correlation between neighboring districts was 0.58 (95% CI 0.42-0.73). Risk analysis for the seven districts with the highest incidence rates indicated that precipitation, neighboring-district effect, and infection carryover effect exhibited significant correlation with district-level incidence dynamics. Model-predicted incidence dynamics and case distribution matched well with observed results, except for the outbreak in 2018. The model-predicted 2020 case number is about 5,400 cases, with intensified transmission and expansion of high-transmission area. The predicted case number will be 9115 in 2022 and 19212 in 2025. CONCLUSIONS: The drastic upsurge in leishmaniasis cases in Sri Lanka in the last few year was unprecedented and it was strongly linked to precipitation, high burden of localized infections and inter-district dispersal. Targeted interventions are urgently needed to arrest an uncontrollable disease spread.Item Tissue impression smears as a supplementary diagnostic method for histopathology in cutaneous leishmaniasis in Sri Lanka(American Society of Tropical Medicine and Hygiene, 2018) Manamperi, N.H.; de Silva, M.V.C.; Pathirana, N.; Abeyewickreme, W.; Karunaweera, N.D.Cutaneous leishmaniasis (CL) is diagnosed mainly by light microscopy of smears made using lesion material. Histopathology is usually done in atypical presentations or when lesion smears are negative. Tissue impression smears (TIS) made from skin biopsy specimens were compared with histopathology for the diagnosis of CL. Out of the 111 patients included, 83 (74.8%) were positive by either methods. The TIS was positive in 70.3% whereas histopathology was positive in 56.8% of patients. Tissue impression smears can be used as a supplementary diagnostic test that gives sensitive and rapid results when tissue biopsies are used as the source of lesion material for diagnosis of CL.Item Clinical and histopathological characteristics of cutaneous leishmaniasis in a group of military personnel in Sri Lanka(American Society of Tropical Medicine and Hygiene, 2015) Manamperi, N.H.; Fernando, C.S.; Pathirana, A.; Abeyewickreme, W.; de Silva, V.C.; Karunaweera, N.D.Cutaneous leishmaniasis (CL) is a newly established vector-borne parasitic disease in Sri Lanka. Military personnel have an occupational risk for CL due to being stationed in endemic areas and exposure to vectors outdoors. This study describes the clinical and histopathological features of CL in a group of military personnel. Thirty five patients with smear positive for Leishmania amastigotes were included, their data analyzed for clinical features and skin biopsies processed routinely for histology, examined at a conference microscope and classified into 4 groups using modified Ridley criteria for Leishmaniasis as: I-parasitized macrophages with variable lymphocytes and plasma cells; II-parasitized macrophages with lymphocytes, plasma cells and ill formed histiocytic granulomata; III-a mixture of macrophages (with or without parasites), lymphocytes, plasma cells and epithelioid granulomata; IV-epithelioid granulomatous response with a few lymphocytes and plasma cells but no amastigotes. Lesions were categorized by duration, as acute (< 6 months) or chronic (> 6 months). Study group composed of all males with a mean age of 32.6 years (range 22-47) and lesion duration of 5.6 months (range 1-24). Number of lesions varied from 1 to 6 with majority (71.4%, n= 25) having a single lesion. Nodular (37.1%, n=13) and nodulo-ulcerative (25.7%, n=9) lesions in upper limbs (68.6%, n=24) was the commonest presentation. Twenty nine (82.9%) of the biopsies were positive also by histology. Twenty two (62.9%) were acute and 13 (37.1%) chronic. Group I, II, III and IV patterns were seen in 14 (40%), 12 (34.3%), 5 (14.3%) and 4 (11.4%) respectively and 9 (40.9%), 9 (40.9%), 2 (9.1%) and 2 (9.1%) of acute lesions and 5 (38.5%), 3 (23.1%), 3 (23.1%) and 2 (15.4%) of chronic lesions respectively. Necrosis was not seen in any of the lesions. Majority in this group of military personnel with CL had single lesions affecting the upper limbs and sought treatment within 2 years of appearance of lesions. The histological picture varied from diffuse infiltration of parasitized macrophages admixed with chronic inflammatory cells to ill-formed histiocytic granulomata.Item In situ immune response to cutaneous leishmaniasis in Sri Lanka(Sri Lanka Medical Association, 2017) Manamperi, N.H.; Oghumu, S.; Pathirana, N.; de Silva, M.V.C.; Abeyewickreme, W.; Satoskar, A.R.; Karunaweera, N.D.INTRODUCTION & OBJECTIVES: Cutaneous leishmaniasis (CL) in Sri Lanka is caused by Leishmania donovani-MON 37, known to cause visceral leishmaniasis elsewhere. Localized immune response may play a role in disease outcome with T helper (Th) 1 response favouring lesion healing and Th2 response leading to disease progression in animal models. This study describes the localized host immune response to CL in Sri Lanka. METHOD: Skin punch biopsies from 58 patients with parasitologically confirmed CL and 25 healthy controls were quantified for cytokine gene expression of Th1 cytokines interferon (IFN)-γ, interleukin (IL)-12A and tumour necrosis factor (TNF)-α and Th2 cytokines, IL-4 and IL-10 by real-time RT-PCR. Relative copy numbers were calculated using the 2-ΔΔCt method. Non-parametric Mann-Whitney U test and the Spearman’s correlation test were used for statistical analysis. RESULTS: Study group consisted of 37 (63.8%) males and 21 (36.2%) females with a mean age of 35.0 years (SD=12.1, range=18-66), mean lesion duration of 6.75 ±9.1 months (range: 1-48) and a mean size of 176.59±185.76 mm2 (range: 12.6–908.3 mm2). Significant up regulation of IFN-γ (p<0.001) and down regulation of IL-4 (p<0.001) were seen in patients compared to healthy controls. Time taken for lesions to heal correlated significantly with in situ expression of IL-4 (Spearman’s r=0.321, p=0.034). CONCLUSION: Immune response to L. donovani induced CL in Sri Lanka tends to follow the typical Th1/Th2 convention with a Th2 biased milieu favouring poor responsiveness to antimony and delayed lesion healing.Item In situ immunopathological changes in cutaneous leishmaniasis due to Leishmania donovani(Oxford, Wiley, 2017) Manamperi, N.H.; Oghumu, S.; Pathirana, N.; de Silva, V.C.; Abeyewickreme, W.; Satoskar, A.R.; Karunaweera, N.D.INTRODUCTION: Cutaneous leishmaniasis in Sri Lanka is a newly established parasitic disease caused by the usually visceralizing Leishmania donovani. Skin lesions manifest as non-itchy, non-tender papules, nodules or ulcers. In situ cytokine expression provides clues for immunopathogenesis of this localized form of disease. METHODS: Skin biopsies from 58 patients were analyzed for histological appearance and in situ cytokine expression of T- helper 1 (Th1) and T- helper 2 (Th2) cytokines, namely interferon (IFN)-γ, interleukin (IL)-12A, tumor necrosis factor (TNF)-α, IL-4 and IL-10 by real-time RT- PCR. RESULTS: Significant up regulation of the Th1 cytokine IFN-γ and down regulation of the Th2 cytokine IL-4 was seen in patients compared to healthy controls. Significantly elevated tissue expression of IFN-γ and TNF-α was seen in lesions that presented later than 6 months from the time of onset, while IL-4 expression was more prominent in lesions that responded poorly to antimony therapy. CONCLUSION: A prominent Th1 response appears to support resolving of lesions, whereas a Th2 biased milieu tends to favor poor responsiveness to antimony and delayed lesion healing in L. donovani infections in Sri Lanka. This article is protected by copyright. All rights reserved.Item Study on Phlebotomine sand flies in selected areas in Sri Lanka(Sri Lanka College of Microbiologists, 2006) Senanayake, S.A.S.C.; Karunaweera, N.D.; Abeyewickreme, W.Sandflies are the known vectors of disease leishmaniasis. Though there are three clinical entities (viceral, mucocutaneous and cutaneous),^.only cutaneous form of the disease is seen in Sri Lanka. Presence of sandflies belonging to six species has been reported from various parts of the country since 1910. But the first indigenous case of cutaneous leishmaniasis was recorded in 1922. The number of cases rapidly increased during past few years and it is now been considered as an established disease. The causative organism of the disease is the protozoan parasite Leishmania donovani MON37. The vector of the Sri Lankan cutaneous leishmaniasis is still unknown. This study was carried out in two selected areas in Kurunegala and Matara ditricts where considerable number of patients was reported to the Department of Parasitology, Faculty of Medicine, Colombo. The objectives of the study were to identify the prevalent sandfly species in selected areas and establish the potential vector(s). The adult sandflies were collectedTrom four different sites in selected areas. Three different methodologies were used (cattle-baited net traps, CDC light traps, manual collection and mechanical aspirators). Collections were done for 18 months from Sep2004. Collected sandflies were dissected under dissecting microscope and mounted on glass slides. The specimens were examined under both light and phase contrast microscopes. A subset of collected samples were sent to CDC, Atlanta for molecular based identification. Blood fed females were subjected to gut dissection to demonstrate the presence of leishmania parasites within the vector. Real time PCR analysis was carried out with a subset of samples using Leishmania donovani primers. Two species of sandfies were identified in both areas. They were Phlebotomus argentepes and Sergentomiya zeylanica, two species which had been reported previously. P. argentepes is the established vector of visceral leishmaniasis in India and latter is a non human disease transmitter. A total of 3587 sandfies were examined (1756 from Matara and 1731 from Kurunegala) Male to female ratio of the collection was 6:1(3075 males and 522 females). Only 88 ( 5.01%) P. argentepes were found in Matara and rest 1168 (94.99%) were S. zeylanica. How ever, Kurunegala collection resulted with 1549 (89.48%) P. argentepes and 192 S. zeylanica. None of the method use to demonstrate leishmania parasites in sandflies gave positive results. Financial assistants by National Science Foundation for research Grant 2005 /HS/07 is acknowledged.Item Histopathological spectrum in acute and chronic cutaneous leishmaniasis in Sri Lanka(Sri Lanka College of Microbiologists, 2015) Manamperi, N.H.; de Silva, M.V.C.; Fernando, C.; Pathirana, K.P.N.; Abeyewickreme, W.; Karunaweera, N.D.OBJECTIVES: To describe the histological spectrum of acute and chronic cutaneous leishmaniasis. METHOD: Patients from Sri Lanka army were recruited by active and passive case detection methods and punch biopsies were obtained. Skin biopsies of 35 patients with smear positive for Leishmania amastigotes were processed routinely for histopathology, examined at a conference microscope and classified into 4 groups using modified Ridley criteria for Leishmaniasis as: I - parasitized macrophages with variable lymphocytes and plasma cells; II - parasitized macrophages with lymphocytes, plasma cells and ill formed histiocytic granulomata; III -a mixture of macrophages (with or without parasites), lymphocytes, plasma cells and epithelioid granulomata; IV - epithelioid granulomatous response with a few lymphocytes and plasma cells but no amasigotes. Lesions were categorized as acute (<6 months) or chronic (> 6 months). RESULTS: Study group composed of males with a mean age of 32.6 years (range 22-47) and lesion duration of 5.6 months (range 1-24). Twenty nine (82.9%) were also positive by histopathology. Twenty two (62.9%) were acute and 13 (37.1%) chronic. Group I, II, III and IV patterns were seen in 14 (40%), 12 (34.3%), 5 (14.3%) and 4 (11.4%) respectively and 9 (40.9%), 9 (40.9%), 2 (9.1%) and 2 (9.1 %) of acute lesions and 5 (38.5%), 3 (23.1 %), 3 (23.1 %) and 2 (15.4%) of chronic lesions respectively. CONCLUSION: Histology of cutaneous leishmaniasis shows marked inflammatory cell infiltrate with or without granuloma formation. Majority of patients presenting with either acute or chronic cutaneous leishmaniasis belong to histological groups I or II. ACKNOWLEDGEMENTS: Financial assistance from the University Grants Commission, Sri Lanka (UGC/VC/DRIC/PG/2013/KLN/ 03) and University of Kelaniya (RP/03/04/06/01/2014) are acknowledged. An abstract based on similar work was presented at the 128"1 Anniversary International Medical Congress of the Sri Lanka Medical Association, 5th to 8th July 2015.
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