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Suarez-Trujillo F, El-Safi S, Juarez I, Palacio-Gruber J, Sanchez-Orta A, Martin-Villa JM, Arnaiz-Villena A. HLA alleles and haplotypes in Sudanese population and their relationship with Mediterraneans. Sci Rep 2023; 13:16203. [PMID: 37758772 PMCID: PMC10533553 DOI: 10.1038/s41598-023-40173-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 08/06/2023] [Indexed: 09/29/2023] Open
Abstract
The contribution of migrated people from once green Sahara (about 10,000-6000 years BC) towards Mediterranean area had probably a double effect: both genetic and cultural connections have been described between Western Europe and North Africa. Sudanese populations from different ethnicities have been studied for HLA-A, -B, -DRB1 and -DQB1 antigens by a standard microlymphotoxicity method. Results found show that Nubians are genetically related with African Sub-Saharan populations and distant from other Sudanese tribes, who are closer to Mediterranean populations than to Sub-Saharan ones. This is concordant with other authors and meta-analysis data. Our present work is, to our knowledge, the first and only one HLA research that studies Sudanese people according to different Sudan ethnic groups: samples were collected before Sudan partition between North and South. A prehistoric genetic and peoples exchange between Africa and the Mediterranean basin may be observed and is supported with the results obtained in this Sudanese HLA study. However, demic diffusion model of agriculture and other anthropological traits from Middle East to West Europe/Maghreb do not exist: a more detailed Sahel and North African countries ancient and recent admixture studies are also being carried out which may clearer explain pastoralists/agriculture innovations origins in Eurafrican Mediterranean and Atlantic façade.
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Affiliation(s)
- Fabio Suarez-Trujillo
- Department of Immunology, School of Medicine, University Complutense, Pabellón 5, Planta 4. Avda. Complutense S/N, 28040, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | | | - Ignacio Juarez
- Department of Immunology, School of Medicine, University Complutense, Pabellón 5, Planta 4. Avda. Complutense S/N, 28040, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - José Palacio-Gruber
- Department of Immunology, School of Medicine, University Complutense, Pabellón 5, Planta 4. Avda. Complutense S/N, 28040, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Alejandro Sanchez-Orta
- Department of Immunology, School of Medicine, University Complutense, Pabellón 5, Planta 4. Avda. Complutense S/N, 28040, Madrid, Spain
| | - José Manuel Martin-Villa
- Department of Immunology, School of Medicine, University Complutense, Pabellón 5, Planta 4. Avda. Complutense S/N, 28040, Madrid, Spain
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Antonio Arnaiz-Villena
- Department of Immunology, School of Medicine, University Complutense, Pabellón 5, Planta 4. Avda. Complutense S/N, 28040, Madrid, Spain.
- Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain.
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Simonson P, Bhattacharyya T, El-Safi S, Miles MA. Linear and conformational determinants of visceral leishmaniasis diagnostic antigens rK28 and rK39. Parasit Vectors 2022; 15:387. [PMID: 36273150 PMCID: PMC9587664 DOI: 10.1186/s13071-022-05495-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 09/14/2022] [Indexed: 11/10/2022] Open
Abstract
Background Recombinant antigens rK39 (based on kinesin sequence) and rK28 (comprising kinesin and HASPB sequences) are a mainstay of serological diagnosis for visceral leishmaniasis (VL). However, their key epitopes and the significance of their structural conformation are not clearly defined, particularly in relation to reported cross-reactivity with sera from patients with malaria, schistosomiasis, and tuberculosis. Methods To assess the effect of conformation on antigenicity with Sudanese VL sera, antigens rK39 and rK28 were heat-denatured at 95 °C for 10 min and then assayed by enzyme-linked immunosorbent assay (ELISA). Amino acid sequences of rK39 and rK28 were submitted to NCBI BLASTp to assess homology with Plasmodium, Schistosoma, and Mycobacterium. Results Heat denaturation significantly diminished the antigenicity of rK39 compared to non-denatured antigen (P = 0.001), but not for rK28 (P = 0.275). In BLASTp searches, HASPB sequences from rK28 had similarities with sequences from Plasmodium, encompassing software-predicted B-cell epitopes. Conclusions The antigenicity of rK39 appears to be dependent on structural conformation, whereas that of rK28 depends on linear sequence. HASPB sequence homology with Plasmodium may be responsible for the reported cross-reactivity of rK28 with malaria sera. Further work is warranted to refine the specificity of these antigens. Graphical Abstract ![]()
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Affiliation(s)
- Poppy Simonson
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
| | - Tapan Bhattacharyya
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Sayda El-Safi
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Michael A Miles
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
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Marlais T, Bhattacharyya T, Pearson C, Gardner BL, Marhoon S, Airs S, Hayes K, Falconar AK, Singh OP, Reed SG, El-Safi S, Sundar S, Miles MA. Isolation and characterisation of Leishmania donovani protein antigens from urine of visceral leishmaniasis patients. PLoS One 2020; 15:e0238840. [PMID: 32925980 PMCID: PMC7489519 DOI: 10.1371/journal.pone.0238840] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 08/25/2020] [Indexed: 12/21/2022] Open
Abstract
Diagnosis of visceral leishmaniasis (VL) relies on invasive and risky aspirate procedures, and confirmation of cure after treatment is unreliable. Detection of Leishmania donovani antigens in urine has the potential to provide both a non-invasive diagnostic and a test of cure. We searched for L. donovani antigens in urine of VL patients from India and Sudan to contribute to the development of urine antigen capture immunoassays. VL urine samples were incubated with immobilised anti-L. donovani polyclonal antibodies and captured material was eluted. Sudanese eluted material and concentrated VL urine were analysed by western blot. Immunocaptured and immunoreactive material from Indian and Sudanese urine was submitted to mass spectrometry for protein identification. We identified six L. donovani proteins from VL urine. Named proteins were 40S ribosomal protein S9, kinases, and others were hypothetical. Thirty-three epitope regions were predicted with high specificity in the 6 proteins. Of these, 20 were highly specific to Leishmania spp. and are highly suitable for raising antibodies for the subsequent development of an antigen capture assay. We present all the identified proteins and analysed epitope regions in full so that they may contribute to the development of non-invasive immunoassays for this deadly disease.
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Affiliation(s)
- Tegwen Marlais
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Tapan Bhattacharyya
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Callum Pearson
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Bathsheba L. Gardner
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Safiyyah Marhoon
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Stephanie Airs
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Kiera Hayes
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Om Prakash Singh
- Department of Biochemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Steven G. Reed
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Sayda El-Safi
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Shyam Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Michael A. Miles
- Department of Infection Biology, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Mollett G, Bremer Hinckel BC, Bhattacharyya T, Marlais T, Singh OP, Mertens P, Falconar AK, El-Safi S, Sundar S, Miles MA. Detection of Immunoglobulin G1 Against rK39 Improves Monitoring of Treatment Outcomes in Visceral Leishmaniasis. Clin Infect Dis 2020; 69:1130-1135. [PMID: 30541022 PMCID: PMC6743847 DOI: 10.1093/cid/ciy1062] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 12/07/2018] [Indexed: 11/15/2022] Open
Abstract
Background Visceral leishmaniasis (VL), caused by the Leishmania donovani complex, is a fatal, neglected tropical disease that is targeted for elimination in India, Nepal, and Bangladesh. Improved diagnostic tests are required for early case detection and for monitoring the outcomes of treatments. Previous investigations using Leishmania lysate antigen demonstrated that the immunoglobulin (Ig) G1 response is a potential indicator of a patient’s clinical status after chemotherapy. Methods IgG1 or IgG enzyme-linked immunosorbent assays (ELISAs) with rK39 or lysate antigens and novel IgG1 rK39 rapid diagnostic tests (RDTs) were assessed with Indian VL serum samples from the following clinical groups: paired pre- and postchemotherapy (deemed cured); relapsed; other infectious diseases; and endemic, healthy controls. Results With paired pre- and post-treatment samples (n = 37 pairs), ELISAs with rK39- and IgG1-specific conjugates gave a far more discriminative decrease in post-treatment antibody responses when compared to IgG (P < .0001). Novel IgG1 rK39 RDTs provided strong evidence for decreased IgG1 responses in patients who had successful treatment (P < .0001). Furthermore, both IgG1 rK39 RDTs (n = 38) and ELISAs showed a highly significant difference in test outcomes between cured patients and those who relapsed (n = 23; P < .0001). RDTs were more sensitive than corresponding ELISAs. Conclusions We present strong evidence for the use of IgG1 in monitoring treatment outcomes in VL, and the first use of an IgG1-based RDT using the rK39 antigen for the discrimination of post-treatment cure versus relapse in VL. Such an RDT may have a significant role in monitoring patients and in targeted control and elimination of this devastating disease.
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Affiliation(s)
- Guy Mollett
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Bruno C Bremer Hinckel
- Coris BioConcept, Gembloux.,Department of Biomedical Sciences, University of Antwerp, Belgium
| | - Tapan Bhattacharyya
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Tegwen Marlais
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
| | - Om Prakash Singh
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | | | - Andrew K Falconar
- Departamento de Medicina, Universidad del Norte, Barranquilla, Colombia
| | | | - Shyam Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Michael A Miles
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom
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Collis S, El-Safi S, Atia AA, Bhattacharyya T, Hammad A, Den Boer M, Le H, Whitworth JA, Miles MA. Epidemiological and molecular investigation of resurgent cutaneous leishmaniasis in Sudan. Int J Infect Dis 2019; 88:14-20. [PMID: 31442631 PMCID: PMC6838665 DOI: 10.1016/j.ijid.2019.08.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 08/13/2019] [Accepted: 08/14/2019] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVES Local health personnel have drawn attention to an apparent increase in incidence and severity of cutaneous leishmaniasis (CL) in Sudan. The objective of this study was to investigate CL burden and surveillance. METHODS Surveillance data were compiled from the KalaCORE programme, Leishmania coordinators in Northern Kordofan and Southern Darfur, and Khartoum Dermatology Hospital. CL lesions were sampled from 14 suspected cases from Northern Kordofan and the Hospital for Tropical Diseases in Omdurman. PCR-restriction fragment length polymorphism analysis and multilocus sequencing were used to characterize the disease agent. RESULTS All sites reported substantial increases from 2014 to 2016/7, far exceeding World Health Organization case reports for 2014, consistent with a widespread outbreak. Single seasonal peak incidence was observed, except for two peaks in Southern Darfur. In Northern Kordofan, the odds ratio for CL in the 35-44 years age group was 2.6 times higher than in the >45 years age group (p<0.0001); in Southern Darfur, the OR was 2.38 greater in males than females (p<0.0001). Lesions included severe presentations, despite chemotherapy. Leishmania major was identified as the agent. CONCLUSIONS Active surveillance is required to understand the extent of CL in Sudan, as well as training to standardize surveillance, diagnosis, reporting, and quality control. Point-of-care rapid diagnosis would be valuable. Genotyping and phenotyping are required to monitor the emergence of pathogenic strains, drug resistance, outbreaks, and changes in severity.
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Affiliation(s)
- Sarah Collis
- London School of Hygiene and Tropical Medicine, London, UK.
| | | | - Atia A Atia
- World Health Organization, Sudan; KalaCORE Consortium, Sudan.
| | | | - Awad Hammad
- Faculty of Medicine, University of Khartoum, Sudan.
| | - Margriet Den Boer
- Médecins Sans Frontières, Amsterdam, The Netherlands; KalaCORE Consortium, London, UK.
| | - Hai Le
- London School of Hygiene and Tropical Medicine, London, UK.
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Bremer Hinckel BC, Marlais T, Airs S, Bhattacharyya T, Imamura H, Dujardin JC, El-Safi S, Singh OP, Sundar S, Falconar AK, Andersson B, Litvinov S, Miles MA, Mertens P. Refining wet lab experiments with in silico searches: A rational quest for diagnostic peptides in visceral leishmaniasis. PLoS Negl Trop Dis 2019; 13:e0007353. [PMID: 31059497 PMCID: PMC6522066 DOI: 10.1371/journal.pntd.0007353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 05/16/2019] [Accepted: 04/01/2019] [Indexed: 11/19/2022] Open
Abstract
Background The search for diagnostic biomarkers has been profiting from a growing number of high quality sequenced genomes and freely available bioinformatic tools. These can be combined with wet lab experiments for a rational search. Improved, point-of-care diagnostic tests for visceral leishmaniasis (VL), early case detection and surveillance are required. Previous investigations demonstrated the potential of IgG1 as a biomarker for monitoring clinical status in rapid diagnostic tests (RDTs), although using a crude lysate antigen (CLA) as capturing antigen. Replacing the CLA by specific antigens would lead to more robust RDTs. Methodology Immunoblots revealed L. donovani protein bands detected by IgG1 from VL patients. Upon confident identification of these antigens by mass spectrometry (MS), we searched for evidence of constitutive protein expression and presence of antigenic domains or high accessibility to B-cells. Selected candidates had their linear epitopes mapped with in silico algorithms. Multiple high-scoring predicted epitopes from the shortlisted proteins were screened in peptide arrays. The most promising candidate was tested in RDT prototypes using VL and nonendemic healthy control (NEHC) patient sera. Results Over 90% of the proteins identified from the immunoblots did not satisfy the selection criteria and were excluded from the downstream epitope mapping. Screening of predicted epitope peptides from the shortlisted proteins identified the most reactive, for which the sensitivity for IgG1 was 84% (95% CI 60—97%) with Sudanese VL sera on RDT prototypes. None of the sera from NEHCs were positive. Conclusion We employed in silico searches to reduce drastically the output of wet lab experiments, focusing on promising candidates containing selected protein features. By predicting epitopes in silico we screened a large number of peptides using arrays, identifying the most promising one, for which IgG1 sensitivity and specificity, with limited sample size, supported this proof of concept strategy for diagnostics discovery, which can be applied to the development of more robust IgG1 RDTs for monitoring clinical status in VL. Visceral leishmaniasis (VL) is a neglected tropical disease caused by protozoan parasites of the Leishmania donovani complex. Without treatment, VL is fatal. Although diagnostic techniques, mainly based on the detection of anti-Leishmania antibodies are available, invasive procedures such as microscopy from spleen or bone marrow aspirates are still required for the diagnosis of seronegative VL suspects, for the detection of recurrent cases and to confirm cure after successful treatment. Previous investigations showed the potential of IgG1 as a biomarker of post-chemotherapeutic relapse for VL in rapid diagnostic tests (RDTs) sensitised with crude lysate antigen (CLA). Here we employed in silico tools to search for desired protein features in a large number of L. donovani antigens detected by human IgG1 in western blots. We then employed prediction algorithms to profile epitopes from the shortlisted proteins. We screened a panel of high-scoring peptides in a high-throughput manner using arrays, with low reagent consumption. The most reactive peptide was adapted to RDTs, showing promising results of both sensitivity and specificity. This peptide has the potential of replacing the CLAs in IgG1 RDTs. Thus we believe that in silico tools can be used to optimise wet lab experiments for a rational search of biomarkers.
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Affiliation(s)
- Bruno Cesar Bremer Hinckel
- Coris BioConcept, Gembloux, Belgium
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
- * E-mail:
| | - Tegwen Marlais
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Stephanie Airs
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Tapan Bhattacharyya
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Hideo Imamura
- Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | | | - Sayda El-Safi
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Om Prakash Singh
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Shyam Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | | | - Bjorn Andersson
- Department of Cell- and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | | | - Michael A. Miles
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Marlais T, Bhattacharyya T, Singh OP, Mertens P, Gilleman Q, Thunissen C, Hinckel BCB, Pearson C, Gardner BL, Airs S, de la Roche M, Hayes K, Hafezi H, Falconar AK, Eisa O, Saad A, Khanal B, Bhattarai NR, Rijal S, Boelaert M, El-Safi S, Sundar S, Miles MA. Visceral Leishmaniasis IgG1 Rapid Monitoring of Cure vs. Relapse, and Potential for Diagnosis of Post Kala-Azar Dermal Leishmaniasis. Front Cell Infect Microbiol 2018; 8:427. [PMID: 30619774 PMCID: PMC6300496 DOI: 10.3389/fcimb.2018.00427] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 11/28/2018] [Indexed: 01/13/2023] Open
Abstract
Background: There is a recognized need for an improved diagnostic test to assess post-chemotherapeutic treatment outcome in visceral leishmaniasis (VL) and to diagnose post kala-azar dermal leishmaniasis (PKDL). We previously demonstrated by ELISA and a prototype novel rapid diagnostic test (RDT), that high anti-Leishmania IgG1 is associated with post-treatment relapse versus cure in VL. Methodology: Here, we further evaluate this novel, low-cost RDT, named VL Sero K-SeT, and ELISA for monitoring IgG1 levels in VL patients after treatment. IgG1 levels against L. donovani lysate were determined. We applied these assays to Indian sera from cured VL at 6 months post treatment as well as to relapse and PKDL patients. Sudanese sera from pre- and post-treatment and relapse were also tested. Results: Of 104 paired Indian sera taken before and after treatment for VL, when deemed clinically cured, 81 (77.9%) were positive by VL Sero K-SeT before treatment; by 6 months, 68 of these 81 (84.0%) had a negative or reduced RDT test line intensity. ELISAs differed in positivity rate between pre- and post-treatment (p = 0.0162). Twenty eight of 33 (84.8%) Indian samples taken at diagnosis of relapse were RDT positive. A comparison of Indian VL Sero K-SeT data from patients deemed cured and relapsed confirmed that there was a significant difference (p < 0.0001) in positivity rate for the two groups using this RDT. Ten of 17 (58.8%) Sudanese sera went from positive to negative or decreased VL Sero K-SeT at the end of 11–30 days of treatment. Forty nine of 63 (77.8%) PKDL samples from India were positive by VL Sero K-SeT. Conclusion: We have further shown the relevance of IgG1 in determining clinical status in VL patients. A positive VL Sero K-SeT may also be helpful in supporting diagnosis of PKDL. With further refinement, such as the use of specific antigens, the VL Sero K-SeT and/or IgG1 ELISA may be adjuncts to current VL control programmes.
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Affiliation(s)
- Tegwen Marlais
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
| | - Tapan Bhattacharyya
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
| | - Om Prakash Singh
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University Varanasi, India
| | | | | | | | - Bruno C Bremer Hinckel
- Coris BioConcept Gembloux, Belgium.,Department of Biomedical Sciences, University of Antwerp Antwerp, Belgium
| | - Callum Pearson
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
| | - Bathsheba L Gardner
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
| | - Stephanie Airs
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
| | - Marianne de la Roche
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
| | - Kiera Hayes
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
| | - Hannah Hafezi
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
| | - Andrew K Falconar
- Departamento de Medicina, Universidad del Norte Barranquilla, Colombia
| | - Osama Eisa
- Faculty of Medicine, University of Khartoum Khartoum, Sudan
| | | | - Basudha Khanal
- Department of Microbiology, B.P. Koirala Institute of Health Sciences Dharan, Nepal
| | | | - Suman Rijal
- Department of Internal Medicine, B.P. Koirala Institute of Health Sciences Dharan, Nepal
| | - Marleen Boelaert
- Department of Public Health, Institute of Tropical Medicine Antwerp, Belgium
| | - Sayda El-Safi
- Faculty of Medicine, University of Khartoum Khartoum, Sudan
| | - Shyam Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University Varanasi, India
| | - Michael A Miles
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, United Kingdom
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Ravinetto R, Becker SL, Sacko M, El-Safi S, Mahendradhata Y, Lutumba P, Rijal S, Lim K, Sundar S, N'Goran EK, Verdonck K, Utzinger J, Chappuis F, Boelaert M. Governance and Standards in International Clinical Research: The Role of Transnational Consortia. Am J Bioeth 2016; 16:59-61. [PMID: 27653405 DOI: 10.1080/15265161.2016.1214317] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
| | - Sören L Becker
- b Swiss Tropical and Public Health Institute, University of Basel, and Saarland University
| | - Moussa Sacko
- c Institut National de Recherche en Santé Publique
| | | | | | - Pascal Lutumba
- f Institut National de Recherche Biomédicale and University of Kinshasa
| | | | - Kruy Lim
- h Sihanouk Hospital Center of HOPE
| | - Shyam Sundar
- i Kala-Azar Medical Research Centre and Banaras Hindu University
| | - Eliézer K N'Goran
- j Université Félix Houphouët-Boigny and Centre Suisse de Recherches Scientifiques en Côte d'Ivoire
| | | | - Jürg Utzinger
- l Swiss Tropical and Public Health Institute and University of Basel
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Bhattacharyya T, Ayandeh A, Falconar AK, Sundar S, El-Safi S, Gripenberg MA, Bowes DE, Thunissen C, Singh OP, Kumar R, Ahmed O, Eisa O, Saad A, Silva Pereira S, Boelaert M, Mertens P, Miles MA. IgG1 as a potential biomarker of post-chemotherapeutic relapse in visceral leishmaniasis, and adaptation to a rapid diagnostic test. PLoS Negl Trop Dis 2014; 8:e3273. [PMID: 25340782 PMCID: PMC4207679 DOI: 10.1371/journal.pntd.0003273] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2014] [Accepted: 09/14/2014] [Indexed: 12/02/2022] Open
Abstract
Background Visceral leishmaniasis (VL), caused by protozoa of the Leishmania donovani complex, is a widespread parasitic disease of great public health importance; without effective chemotherapy symptomatic VL is usually fatal. Distinction of asymptomatic carriage from progressive disease and the prediction of relapse following treatment are hampered by the lack of prognostic biomarkers for use at point of care. Methodology/Principal Findings All IgG subclass and IgG isotype antibody levels were determined using unpaired serum samples from Indian and Sudanese patients with differing clinical status of VL, which included pre-treatment active VL, post-treatment cured, post-treatment relapsed, and post kala-azar dermal leishmaniasis (PKDL), as well as seropositive (DAT and/or rK39) endemic healthy controls (EHCs) and seronegative EHCs. L. donovani antigen-specific IgG1 levels were significantly elevated in relapsed versus cured VL patients (p<0.0001). Using paired Indian VL sera, consistent with the known IgG1 half-life, IgG1 levels had not decreased significantly at day 30 after the start of treatment (p = 0.8304), but were dramatically decreased by 6 months compared to day 0 (p = 0.0032) or day 15 (p<0.0001) after start of treatment. Similarly, Sudanese sera taken soon after treatment did not show a significant change in the IgG1 levels (p = 0.3939). Two prototype lateral flow immunochromatographic rapid diagnostic tests (RDTs) were developed to detect IgG1 levels following VL treatment: more than 80% of the relapsed VL patients were IgG1 positive; at least 80% of the cured VL patients were IgG1 negative (p<0.0001). Conclusions/Significance Six months after treatment of active VL, elevated levels of specific IgG1 were associated with treatment failure and relapse, whereas no IgG1 or low levels were detected in cured VL patients. A lateral flow RDT was successfully developed to detect anti-Leishmania IgG1 as a potential biomarker of post-chemotherapeutic relapse. Visceral leishmaniasis (VL) is a systemic disease with highest prevalence in South Asia, East Africa, and Brazil. VL is caused by protozoan (unicellular) parasites of the Leishmania donovani complex, transmitted to humans when an infected sandfly takes a bloodmeal. Within the human host, the parasites replicate within cells, particularly of bone marrow and spleen. Without effective treatment, symptomatic VL is usually fatal. As outlined in a recent World Health Organisation report, the development of new diagnostic tools to test for successful cure after chemotherapy is a research priority. In this work we investigated the association of clinical status of VL patients (active pre-treatment, and those deemed cured or relapsed post-treatment) with subclasses of the IgG antibody response made to L. donovani infection. We show that high levels of subclass IgG1 are found in pre-treatment and relapsed patients, but are very much lower in patients deemed to be cured. We further show that the decrease in IgG1 is detectable in patients 6 months after successful treatment, and that this detection method can be adapted to a rapid diagnostic test format requiring minimal technical expertise. Thus we believe that IgG1 levels are potentially a biomarker of post-chemotherapeutic monitoring.
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Affiliation(s)
- Tapan Bhattacharyya
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Armon Ayandeh
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Andrew K Falconar
- Departamento de Medicina, Universidad del Norte, Barranquilla, Colombia
| | - Shyam Sundar
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Sayda El-Safi
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Marissa A Gripenberg
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Duncan E Bowes
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | | | - Om Prakash Singh
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Rajiv Kumar
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India; Immunology and Infection Laboratory, Queensland Institute of Medical Research, Herston, Queensland, Australia
| | - Osman Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan; Department of Laboratory Medicine, Karolinska Insitutet, Stockholm, Sweden
| | - Osama Eisa
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Alfarazdeg Saad
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Sara Silva Pereira
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Marleen Boelaert
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | | | - Michael A Miles
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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Bhattacharyya T, Bowes DE, El-Safi S, Sundar S, Falconar AK, Singh OP, Kumar R, Ahmed O, Boelaert M, Miles MA. Significantly lower anti-Leishmania IgG responses in Sudanese versus Indian visceral leishmaniasis. PLoS Negl Trop Dis 2014; 8:e2675. [PMID: 24587456 PMCID: PMC3930516 DOI: 10.1371/journal.pntd.0002675] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Accepted: 12/17/2013] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Visceral leishmaniasis (VL), a widely distributed systemic disease caused by infection with the Leishmania donovani complex (L. donovani and L. infantum), is almost always fatal if symptomatic and untreated. A rapid point-of-care diagnostic test for anti-Leishmania antibodies, the rK39-immunochromatographic test (rK39-ICT), has high sensitivity and specificity in South Asia but is less sensitive in East Africa. One of the underlying reasons may be continent-specific molecular diversity in the rK39 antigen within the L. donovani complex. However, a second reason may be differences in specific IgG anti-Leishmania levels in patients from different geographical regions, either due to variable antigenicity or immunological response. METHODOLOGY/PRINCIPAL FINDINGS We determined IgG titres of Indian and Sudanese VL patients against whole cell lysates of Indian and Sudanese L. donovani strains. Indian VL patients had significantly higher IgG titres against both L. donovani strains compared to Sudanese VL patients (p<0.0001). Mean reciprocal log10 50% end-point titres (1/log10t50) were i) 3.80 and 3.88 for Indian plasma and ii) 2.13 and 2.09 for Sudanese plasma against Indian and Sudanese antigen respectively (p<0.0001). Overall, the Indian VL patients therefore showed a 46.8-61.7 -fold higher mean ELISA titre than the Sudanese VL patients. The higher IgG titres occurred in children (<16 years old) and adults of either sex from India (mean 1/log10t50: 3.60-4.15) versus Sudan (mean 1/log10t50: 1.88-2.54). The greatest difference in IgG responses was between male Indian and Sudanese VL patients of ≥ 16 years old (mean 1/log10t50: 4.15 versus 1.99 = 144-fold (p<0.0001). CONCLUSIONS/SIGNIFICANCE Anti-Leishmania IgG responses among VL patients in Sudan were significantly lower than in India; this may be due to chronic malnutrition with Zn(2+) deficiency, or variable antigenicity and capacity to generate IgG responses to Leishmania antigens. Such differential anti-Leishmania IgG levels may contribute to lower sensitivity of the rK39-ICT in East Africa.
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Affiliation(s)
- Tapan Bhattacharyya
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
- * E-mail:
| | - Duncan E. Bowes
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Sayda El-Safi
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Shyam Sundar
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | | | - Om Prakash Singh
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Rajiv Kumar
- Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
- Immunology and Infection Laboratory, Queensland Institute of Medical Research, Herston, Queensland, Australia
| | - Osman Ahmed
- Faculty of Medicine, University of Khartoum, Khartoum, Sudan
- Department of Laboratory Medicine, Karolinska Insitutet, Stockholm, Sweden
| | - Marleen Boelaert
- Department of Public Health, Institute of Tropical Medicine, Antwerp, Belgium
| | - Michael A. Miles
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
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11
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Pattabhi S, Whittle J, Mohamath R, El-Safi S, Moulton GG, Guderian JA, Colombara D, Abdoon AO, Mukhtar MM, Mondal D, Esfandiari J, Kumar S, Chun P, Reed SG, Bhatia A. Design, development and evaluation of rK28-based point-of-care tests for improving rapid diagnosis of visceral leishmaniasis. PLoS Negl Trop Dis 2010; 4. [PMID: 20856856 PMCID: PMC2939046 DOI: 10.1371/journal.pntd.0000822] [Citation(s) in RCA: 93] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Accepted: 08/16/2010] [Indexed: 12/01/2022] Open
Abstract
Background Visceral leishmaniasis (VL) is diagnosed by microscopic confirmation of the parasite in bone marrow, spleen or lymph node aspirates. These procedures are unsuitable for rapid diagnosis of VL in field settings. The development of rK39-based rapid diagnostic tests (RDT) revolutionized diagnosis of VL by offering high sensitivity and specificity in detecting disease in the Indian subcontinent; however, these tests have been less reliable in the African subcontinent (sensitivity range of 75–85%, specificity of 70–92%). We have addressed limitations of the rK39 with a new synthetic polyprotein, rK28, followed by development and evaluation of two new rK28-based RDT prototype platforms. Methodology/Principal Findings Evaluation of 62 VL-confirmed sera from Sudan provided sensitivities of 96.8% and 93.6% (95% CI = K28: 88.83–99.61%; K39: 84.30–98.21%) and specificities of 96.2% and 92.4% (95% CI = K28: 90.53–98.95%; K39: 85.54–96.65%) for rK28 and rK39, respectively. Of greater interest was the observation that individual VL sera with low rK39 reactivity often had much higher rK28 reactivity. This characteristic of the fusion protein was exploited in the development of rK28 rapid tests, which may prove to be crucial in detecting VL among patients with low rK39 antibody levels. Evaluation of two prototype lateral flow-based rK28 rapid tests on 53 VL patients in Sudan and 73 VL patients in Bangladesh provided promisingly high sensitivities (95.9% [95% CI = 88.46–99.1 in Sudan and 98.1% [95% CI = 89.93–99.95%] in Bangladesh) compared to the rK39 RDT (sensitivities of 86.3% [95% CI = 76.25–93.23%] in Sudan and 88.7% [95% CI = 76.97–95.73%] in Bangladesh). Conclusions/Significance Our study compares the diagnostic accuracy of rK39 and rK28 in detecting active VL cases and our findings indicate that rK28 polyprotein has great potential as a serodiagnostic tool. A new rK28-based RDT will prove to be a valuable asset in simplifying VL disease confirmation at the point-of-care. Visceral Leishmaniasis caused by Leishmania donovani is endemic in several parts of South Asia, East Africa, South and Central America. It is a vector-borne disease transmitted by bites of infected sand flies and often fatal in the absence of chemotherapy. Timely diagnosis is an essential first step in providing proper patient care and in controlling transmission. VL diagnosis in East Africa and Latin America are currently based on microscopic confirmation of parasites in tissue aspirates. The Kalazar Detect rapid test is widely used as a confirmatory test in India with very high accuracy, but sensitivity issues have severely limited its usefulness in the African sub-continent. Direct Agglutination Test is another confirmatory test used widely in East Africa and offers high sensitivity but is not field-friendly. We report on the design of a novel synthetic fusion protein capable of sequestering antibodies against three different Leishmania donovani antigens and the development of point-of-care tests for improving VL diagnosis. We believe the ease of use of these rapid tests and their high accuracy in detecting VL cases could make them useful as a first-line test, thereby eliminating the need for painful biopsies and ensuring better patient care.
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Affiliation(s)
- Sowmya Pattabhi
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Jacqueline Whittle
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Raodoh Mohamath
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Sayda El-Safi
- Department of Microbiology and Parasitology, Faculty of Medicine, Khartoum University, Khartoum, Sudan
| | - Garner G. Moulton
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Jeffrey A. Guderian
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Danny Colombara
- Department of Epidemiology, School of Public Health, University of Washington, Seattle, Washington, United States of America
| | - Asem O. Abdoon
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Maowia M. Mukhtar
- Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan
| | - Dinesh Mondal
- Laboratory Sciences Division, International Centre for Diarrhoeal Diseases Research, Dhaka, Bangladesh
| | - Javan Esfandiari
- Chembio Diagnostic Systems, Inc., Medford, New York, United States of America
| | - Shailendra Kumar
- Chembio Diagnostic Systems, Inc., Medford, New York, United States of America
| | - Peter Chun
- Ease-Medtrend, Shanghai, People's Republic of China
| | - Steven G. Reed
- Infectious Disease Research Institute, Seattle, Washington, United States of America
| | - Ajay Bhatia
- Infectious Disease Research Institute, Seattle, Washington, United States of America
- * E-mail:
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12
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Saad AA, Ahmed NG, Osman OS, Al-Basheer AA, Hamad A, Deborggraeve S, Büscher P, Schoone GJ, Schallig HD, Laurent T, Haleem A, Osman OF, Eltom AM, Elbashir MI, El-Safi S. Diagnostic accuracy of the Leishmania OligoC-TesT and NASBA-Oligochromatography for diagnosis of leishmaniasis in Sudan. PLoS Negl Trop Dis 2010; 4:e776. [PMID: 20689822 PMCID: PMC2914782 DOI: 10.1371/journal.pntd.0000776] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2010] [Accepted: 06/28/2010] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The Leishmania OligoC-TesT and NASBA-Oligochromatography (OC) were recently developed for simplified and standardised molecular detection of Leishmania parasites in clinical specimens. We here present the phase II evaluation of both tests for diagnosis of visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and post kala-azar dermal leishmaniasis (PKDL) in Sudan. METHODOLOGY The diagnostic accuracy of the tests was evaluated on 90 confirmed and 90 suspected VL cases, 7 confirmed and 8 suspected CL cases, 2 confirmed PKDL cases and 50 healthy endemic controls from Gedarif state and Khartoum state in Sudan. PRINCIPAL FINDINGS The OligoC-TesT as well as the NASBA-OC showed a sensitivity of 96.8% (95% CI: 83.8%-99.4%) on lymph node aspirates and of 96.2% (95% CI: 89.4%-98.7%) on blood from the confirmed VL cases. The sensitivity on bone marrow was 96.9% (95% CI: 89.3%-99.1%) and 95.3% (95% CI: 87.1%-98.4%) for the OligoC-TesT and NASBA-OC, respectively. All confirmed CL and PKDL cases were positive with both tests. On the suspected VL cases, we observed a positive OligoC-TesT and NASBA-OC result in 37.1% (95% CI: 23.2%-53.7%) and 34.3% (95% CI: 20.8%-50.9%) on lymph, in 72.7% (95% CI: 55.8%-84.9%) and 63.6% (95% CI: 46.6%-77.8%) on bone marrow and in 76.9% (95% CI: 49.7%-91.8%) and 69.2% (95% CI: 42.4%-87.3%) on blood. Seven out of 8 CL suspected cases were positive with both tests. The specificity on the healthy endemic controls was 90% (95% CI: 78.6%-95.7%) for the OligoC-TesT and 100% (95% CI: 92.9%-100.0%) for the NASBA-OC test. CONCLUSIONS Both tests showed high sensitivity on lymph, blood and tissue scrapings for diagnosis of VL, CL and PKDL in Sudan, but the specificity for clinical VL was significantly higher with NASBA-OC.
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Affiliation(s)
| | - Nuha G. Ahmed
- Department of Biochemistry, Khartoum University, Sudan
| | | | | | - Awad Hamad
- Department of Microbiology and Parasitology, Khartoum University, Sudan
| | - Stijn Deborggraeve
- Department of Parasitology, Institute of Tropical Medicine, Antwerp, Belgium
- Rega Institute, Katholieke Universiteit Leuven, Leuven, Belgium
- * E-mail:
| | - Philippe Büscher
- Department of Parasitology, Institute of Tropical Medicine, Antwerp, Belgium
| | - Gerard J. Schoone
- KIT Biomedical Research, Parasitology Unit, Koninklijk Instituut voor de Tropen (KIT), Amsterdam, The Netherlands
| | - Henk D. Schallig
- KIT Biomedical Research, Parasitology Unit, Koninklijk Instituut voor de Tropen (KIT), Amsterdam, The Netherlands
| | | | - Ahmed Haleem
- Faculty of Laboratory Science, Khartoum University, Sudan
| | | | | | | | - Sayda El-Safi
- Department of Microbiology and Parasitology, Khartoum University, Sudan
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13
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Basiye FL, Mbuchi M, Magiri C, Kirigi G, Deborggraeve S, Schoone GJ, Saad AA, El-Safi S, Matovu E, Wasunna MK. Sensitivity and specificity of the Leishmania OligoC-TesT and NASBA-oligochromatography for diagnosis of visceral leishmaniasis in Kenya. Trop Med Int Health 2010; 15:806-10. [PMID: 20487428 DOI: 10.1111/j.1365-3156.2010.02548.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To estimate the sensitivity and specificity of the OligoC-TesT and nucleic acid sequence-based amplification coupled to oligochromatography (NASBA-OC) for molecular detection of Leishmania in blood from patients with confirmed visceral leishmaniasis (VL) and healthy endemic controls from Kenya. METHODS Blood specimens of 84 patients with confirmed VL and 98 endemic healthy controls from Baringo district in Kenya were submitted to both assays. RESULTS The Leishmania OligoC-TesT showed a sensitivity of 96.4% (95% confidence interval [CI]: 90-98.8%) and a specificity of 88.8% (95% CI: 81-93.6%), while the sensitivity and specificity of the NASBA-OC were 79.8% (95% CI: 67-87%) and 100% (95% CI: 96.3-100%), respectively. CONCLUSION Our findings indicate high sensitivity of the Leishmania OligoC-TesT on blood while the NASBA-OC is a better marker for active disease.
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Affiliation(s)
- Frank L Basiye
- Centre for Clinical Research, Kenya Medical Research Institute, Nairobi, Kenya
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14
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Deborggraeve S, Laurent T, Espinosa D, Van der Auwera G, Mbuchi M, Wasunna M, El-Safi S, Al-Basheer AA, Arévalo J, Miranda-Verástegui C, Leclipteux T, Mertens P, Dujardin JC, Herdewijn P, Büscher P. A simplified and standardized polymerase chain reaction format for the diagnosis of leishmaniasis. J Infect Dis 2009; 198:1565-72. [PMID: 18816188 PMCID: PMC7109679 DOI: 10.1086/592509] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Background. Definite diagnosis of Leishmania infections is based on demonstration of the parasite by microscopic analysis of tissue biopsy specimens or aspirate samples. However, microscopy generally shows low sensitivity and requires invasive sampling. Methods. We describe here the development of a simple and rapid test for the detection of polymerase chain reaction-amplified Leishmania DNA. A phase 1 evaluation of the text was conducted in clinical samples from 60 nonendemic and 45 endemic control subjects and from 44 patients with confirmed cutaneous leishmaniasis (CL), 12 with mucocutaneous leishmaniasis (MCL), and 43 with visceral leishmaniasis (VL) from Peru, Kenya, and Sudan. Results. The lower detection limits of the assay are 10 fg of Leishmania DNA and 1 parasite in 180 µL of blood. The specificity was 98.3% (95% confidence interval [CI], 91.1%–99.7%) and 95.6% (95% CI, 85.2%–98.8%) for nonendemic and endemic control samples, respectively, and the sensitivity was 93.2% (95% CI, 81.8%–97.7%), 91.7% (95% CI, 64.6%–98.5%), and 86% (95% CI, 72.7%–93.4%) for lesions from patients with CL or MCL and blood from patients with VL, respectively. Conclusions. The Leishmania OligoC-TesT showed high specificity and sensitivity in clinical samples and was able to detect the parasite in samples obtained by less invasive means, such as blood, lymph, and lesion scrapings. The assay is a promising new tool for simplified and standardized molecular detection of Leishmania parasites.
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Affiliation(s)
- Stijn Deborggraeve
- Department of Parasitology, Institute of Tropical Medicine Antwerp, Antwerp, Belgium.
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15
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Boelaert M, El-Safi S, Hailu A, Mukhtar M, Rijal S, Sundar S, Wasunna M, Aseffa A, Mbui J, Menten J, Desjeux P, Peeling RW. Diagnostic tests for kala-azar: a multi-centre study of the freeze-dried DAT, rK39 strip test and KAtex in East Africa and the Indian subcontinent. Trans R Soc Trop Med Hyg 2007; 102:32-40. [PMID: 17942129 DOI: 10.1016/j.trstmh.2007.09.003] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 09/04/2007] [Accepted: 09/04/2007] [Indexed: 11/26/2022] Open
Abstract
Three diagnostic tests for visceral leishmaniasis (VL), the freeze-dried direct agglutination test (FD-DAT), the rK39 dipstick and a urine latex antigen test (KAtex), were evaluated for use in primary care in East Africa and the Indian subcontinent. Clinical suspects were prospectively recruited and tissue, blood and urine samples were taken. Direct microscopic examination of tissue smear, and FD-DAT, rK39 and KAtex were performed. Sensitivity and specificity with 95% credible intervals were estimated using Bayesian latent class analysis. On the Indian subcontinent both the FD-DAT and the rK39 strip test exceeded the 95% sensitivity and 90% specificity target, but not so in East Africa. Sensitivity of the FD-DAT was high in Ethiopia and Kenya but lower in Sudan, while its specificity was below 90% in Kenya. Sensitivity of the rK39 was below 80% in the three countries, and its specificity was only 70% in Ethiopia. KAtex showed moderate to very low sensitivity in all countries. FD-DAT and rK39 can be recommended for clinical practice on the Indian subcontinent. In East Africa, their clinical use should be carefully monitored. More work is needed to improve existing formats, and to develop better VL diagnostics.
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Affiliation(s)
- M Boelaert
- Epidemiology and Disease Control Unit, Institute of Tropical Medicine, Nationalestraat 155, 2000 Antwerp, Belgium.
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El-Safi S, Kheir MM, Bucheton B, Argiro L, Abel L, Dereure J, Dedet JP, Dessein A. Genes and environment in susceptibility to visceral leishmaniasis. C R Biol 2006; 329:863-70. [PMID: 17067929 DOI: 10.1016/j.crvi.2006.07.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Revised: 07/10/2006] [Accepted: 07/12/2006] [Indexed: 10/24/2022]
Abstract
Kala azar (KA) is a lethal disease caused by Leishmania parasites (Leishmania donovani s.l.) that multiply in large numbers in deep organs such as spleen and liver. The host immunological response to these organisms is complex and experimental studies in animals have detected a large number of genetic loci involved in the control of infection and disease. We report here on a study in a human population of Sudan carried out during an outbreak of KA. The following conclusions are presented: (1) environmental factors that could have affected the distribution of the insect vector, influenced progression of KA in the initial phase of the epidemics - but they became less important later at the peak of transmission, probably after infected phlebotomies had spread to all parts of the village -; (2) Leishmania population during the epidemics was heterogeneous, suggesting a possible parasite evolution during the outbreak; (3) the incidence of KA varied markedly among age groups, families and ethnic groups. Susceptibility to KA was shown to depend on a locus on chromosomes 22q12 and on NRAMP1 on chromosome 2q35; the data also suggested a third locus in the region 2q23-q24. Overall, this study indicates complex interactions between host genes and environment in the spreading of KA in that population. It is also suspected that the large parasite diversity observed in the outbreak has contributed to disease spreading across host genetic barriers.
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Affiliation(s)
- Sayda El-Safi
- Department of Parasitology and Microbiology, Faculty of Medicine, Khartoum, Sudan
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17
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Bucheton B, Abel L, El-Safi S, Kheir MM, Pavek S, Lemainque A, Dessein AJ. A major susceptibility locus on chromosome 22q12 plays a critical role in the control of kala-azar. Am J Hum Genet 2003; 73:1052-60. [PMID: 14557985 PMCID: PMC1180485 DOI: 10.1086/379084] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2003] [Accepted: 08/11/2003] [Indexed: 01/13/2023] Open
Abstract
Kala-azar (KA) is a life-threatening protozoal disease caused by Leishmania parasites (L. donovani, L. chagasi, and L. infantum). The disease, which is also called "visceral leishmaniasis," is prevalent in Africa, South America, Asia, and the Mediterranean basin. Epidemics occur periodically, killing a large number of infected individuals. Factors determining whether a patient remains asymptomatic or develops KA are still largely unknown. In a previous study that was performed during an outbreak of KA in a village on the Ethiopian-Sudanese border, we showed that KA was more frequent in certain families and ethnic groups, thereby suggesting that host genetic factors play an important role in the development of the disease. Here, we report the results of a genomewide linkage study performed on 63 Sudanese families selected from the most affected ethnic group and including 169 children with KA. Significant linkage (LOD score 3.50 [P=3x10-5] in all patients; LOD score 3.90 [P=10-5] in patients who were affected early in the outbreak) was obtained with markers on chromosome 22q12. These results are the first evidence of a major genetic effect on the development of human KA. They may lead to identification of genes critical in the pathogenesis of this disease and to new therapeutic interventions against this parasite, which is developing resistance to available drugs.
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Affiliation(s)
- Bruno Bucheton
- INSERM U399, Immunology and Genetics of Parasitic Diseases, Faculté de Médecine La Timone, Paris, France
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Sugimoto C, Kitamura T, Guo J, Al-Ahdal MN, Shchelkunov SN, Otova B, Ondrejka P, Chollet JY, El-Safi S, Ettayebi M, Grésenguet G, Kocagöz T, Chaiyarasamee S, Thant KZ, Thein S, Moe K, Kobayashi N, Taguchi F, Yogo Y. Typing of urinary JC virus DNA offers a novel means of tracing human migrations. Proc Natl Acad Sci U S A 1997; 94:9191-6. [PMID: 9256458 PMCID: PMC23108 DOI: 10.1073/pnas.94.17.9191] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Although polyomavirus JC (JCV) is the proven pathogen of progressive multifocal leukoencephalopathy, the fatal demyelinating disease, this virus is ubiquitous as a usually harmless symbiote among human beings. JCV propagates in the adult kidney and excretes its progeny in urine, from which JCV DNA can readily be recovered. The main mode of transmission of JCV is from parents to children through long cohabitation. In this study, we collected a substantial number of urine samples from native inhabitants of 34 countries in Europe, Africa, and Asia. A 610-bp segment of JCV DNA was amplified from each urine sample, and its DNA sequence was determined. A worldwide phylogenetic tree subsequently constructed revealed the presence of nine subtypes including minor ones. Five subtypes (EU, Af2, B1, SC, and CY) occupied rather large territories that overlapped with each other at their boundaries. The entire Europe, northern Africa, and western Asia were the domain of EU, whereas the domain of Af2 included nearly all of Africa and southwestern Asia all the way to the northeastern edge of India. Partially overlapping domains in Asia were occupied by subtypes B1, SC, and CY. Of particular interest was the recovery of JCV subtypes in a pocket or pockets that were separated by great geographic distances from the main domains of those subtypes. Certain of these pockets can readily be explained by recent migrations of human populations carrying these subtypes. Overall, it appears that JCV genotyping promises to reveal previously unknown human migration routes: ancient as well as recent.
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Affiliation(s)
- C Sugimoto
- Department of Viral Infection, the Institute of Medical Science, the University of Tokyo, Tokyo, Japan
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