{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T00:20:34Z","timestamp":1790382034629,"version":"4.1.0"},"reference-count":28,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2022,1,20]],"date-time":"2022-01-20T00:00:00Z","timestamp":1642636800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Visceral leishmaniasis (VL) is one of the major global health concerns due to its association with morbidity and mortality. All available diagnostic tools have been, until now, unable to provide a very specific and cost-effective mode of detection for VL globally. Therefore, the design of robust, specific, and commercially translatable diagnostic tests is urgently required. Currently, we are attempting to identify and explore the diagnostic potential of a novel parasite antigen. Repressor of differentiation kinase 2 (RDK2), a serine\/threonine kinase, has a versatile role in parasite life cycle progression. However, its role as a diagnostic candidate for VL has not been investigated. Herein, we cloned and over-expressed LdRDK2 and studied the recombinant RDK2 for the diagnosis of human VL using serum and urine samples. In silico analysis predicted that RDK2 is conserved among Leishmania species with the least conservation in humans. RDK2 developed immune-reactive bands with antibodies present in VL patients\u2019 sera, and it demonstrated no cross-reactivity with sera from healthy controls and other diseases. Additionally, RDK2 antigen demonstrated a significant reactivity with IgG antibodies of VL patients\u2019 sera, with 78% sensitivity and 86.67% specificity as compared to healthy controls and other diseases. Furthermore, we evaluated its utility for non-invasive diagnosis of VL using patients\u2019 urine samples and found 93.8% sensitivity and 85.7% specificity. RDK2 was found to have better sensitivity and treatment response in patients\u2019 urine compared to serum samples, indicating its role as a promising point of care (POC) antigen. In a nutshell, we explored the role of RDK2 as a potential diagnostic marker for VL in both invasive and non-invasive modes as well as its utility as a promising POC antigen for treatment response cases.<\/jats:p>","DOI":"10.3390\/pathogens11020120","type":"journal-article","created":{"date-parts":[[2022,1,20]],"date-time":"2022-01-20T22:51:06Z","timestamp":1642719066000},"page":"120","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Revealing a Novel Antigen Repressor of Differentiation Kinase 2 for Diagnosis of Human Visceral Leishmaniasis in India"],"prefix":"10.3390","volume":"11","author":[{"given":"Anirban","family":"Bhattacharyya","sequence":"first","affiliation":[{"name":"Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata 700032, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohd","family":"Kamran","sequence":"additional","affiliation":[{"name":"Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata 700032, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sarfaraz Ahmad","family":"Ejazi","sequence":"additional","affiliation":[{"name":"Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata 700032, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sonali","family":"Das","sequence":"additional","affiliation":[{"name":"Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata 700032, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicky","family":"Didwania","sequence":"additional","affiliation":[{"name":"Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata 700032, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rahul","family":"Bhattacharjee","sequence":"additional","affiliation":[{"name":"Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata 700032, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mehebubar","family":"Rahaman","sequence":"additional","affiliation":[{"name":"Department of Tropical Medicine, School of Tropical Medicine, Kolkata 700073, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rama Prosad","family":"Goswami","sequence":"additional","affiliation":[{"name":"Department of Tropical Medicine, School of Tropical Medicine, Kolkata 700073, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Krishna","family":"Pandey","sequence":"additional","affiliation":[{"name":"Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, Patna 800007, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vidya Nand Ravi","family":"Das","sequence":"additional","affiliation":[{"name":"Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, Patna 800007, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pradeep","family":"Das","sequence":"additional","affiliation":[{"name":"Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, Patna 800007, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Saswati","family":"Gayen","sequence":"additional","affiliation":[{"name":"Department of Microbiology, VijaygarhJyotish Ray College, Bejoygarh 700032, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nahid","family":"Ali","sequence":"additional","affiliation":[{"name":"Infectious Diseases and Immunology Division, Indian Institute of Chemical Biology, Kolkata 700032, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,1,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Malvolti, S., Malhame, M., Mantel, C.F., Le Rutte, E.A., and Kaye, P.M. (2021). Human leishmaniasis vaccines: Use cases, target population and potential global demand. PLoS Negl. Trop. Dis., 15.","DOI":"10.1101\/2021.07.09.21260268"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Ejazi, S.A., Choudhury, S.T., Bhattacharyya, A., Kamran, M., Pandey, K., Das, V.N.R., Das, P., da Silva, F.O., Costa, D.L., and Costa, C.H.N. (2021). Development and Clinical Evaluation of Serum and Urine-Based Lateral Flow Tests for Diagnosis of Human Visceral Leishmaniasis. Microorganisms, 9.","DOI":"10.3390\/microorganisms9071369"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Crupi, R., Gugliandolo, E., Siracusa, R., Impellizzeri, D., Cordaro, M., Di Paola, R., Britti, D., and Cuzzocrea, S. (2020). N-acetyl-L-cysteine reduces Leishmania amazonensis-induced inflammation in BALB\/c mice. BMC Vet. Res., 16.","DOI":"10.1186\/s12917-020-2234-9"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"929","DOI":"10.4269\/ajtmh.2009.80.929","article-title":"Field evaluation of rK39 test and direct ag-glutination test for diagnosis of visceral leishmaniasis in a population with high prevalence of human immunodeficiency virus in Ethiopia","volume":"80","author":"Tefera","year":"2009","journal-title":"Am. J. Trop. Med. Hyg."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"414","DOI":"10.1016\/j.trstmh.2011.04.010","article-title":"Direct agglutination test (DAT): Improvement of biosafety for laboratory diagnosis of visceral leishmaniasis","volume":"105","author":"Oliveira","year":"2011","journal-title":"Trans. R. Soc. Trop. Med. Hyg."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"9932","DOI":"10.1038\/s41598-019-46283-9","article-title":"A multicentric evaluation of dipstick test for serodiagnosis of visceral leishmaniasis in India, Nepal, Sri Lanka, Brazil, Ethiopia and Spain","volume":"9","author":"Ejazi","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Gugliandolo, E., Palma, E., Peritore, A.F., Siracusa, R., D\u2019Amico, R., Fusco, R., Licata, P., and Crupi, R. (2020). Effect of Artesunate on Leishmania Amazonesis Induced Neuroinflammation and Nociceptive Behavior in Male Balb\/C Mice. Animals, 10.","DOI":"10.3390\/ani10040557"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3541","DOI":"10.1007\/s00436-020-06845-7","article-title":"Parasitemia and its daily variation in canine leishmaniasis","volume":"119","author":"Falcone","year":"2020","journal-title":"Parasitol. Res."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"K\u00fchne, V., Rezaei, Z., Pitzinger, P., and B\u00fcscher, P. (2019). Systematic review on antigens for serodiagnosis of visceral leishmaniasis, with a focus on East Africa. PLoS Negl. Trop. Dis., 13.","DOI":"10.1371\/journal.pntd.0007658"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1312","DOI":"10.1093\/cid\/cis716","article-title":"A Global Comparative Evaluation of Commercial Immunochromatographic Rapid Diagnostic Tests for Visceral Leishmaniasis","volume":"55","author":"Cunningham","year":"2012","journal-title":"Clin. Infect. Dis."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1016\/j.diagmicrobio.2007.09.001","article-title":"A urine-based polymerase chain reaction method for the diagnosis of visceral leishmaniasis in immunocompetent patients","volume":"60","author":"Motazedian","year":"2008","journal-title":"Diagn. Microbiol. Infect. Dis."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1128\/CVI.00473-10","article-title":"Persistence of Leishmania donovani Antibodies in Past Visceral Leishmaniasis Cases in India","volume":"18","author":"Gidwani","year":"2011","journal-title":"Clin. Vaccine Immunol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"951","DOI":"10.1016\/S0140-6736(18)31204-2","article-title":"Leishmaniasis","volume":"392","author":"Burza","year":"2018","journal-title":"Lancet"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1038\/nrmicro841","article-title":"Diagnostics for the developing world","volume":"2","author":"Mabey","year":"2004","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"805","DOI":"10.1080\/14787210.2018.1532790","article-title":"Visceral leishmaniasis elimination targets in India, strategies for preventing resurgence","volume":"16","author":"Sundar","year":"2018","journal-title":"Expert Rev. Anti-Infect. Ther."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Ejazi, S.A., Bhattacharya, P., Bakhteyar, A.K., Mumtaz, A.A., Pandey, K., Das, V.N.R., Das, P., Rahaman, M., Goswami, R.P., and Ali, N. (2016). Noninvasive Diagnosis of Visceral Leishmaniasis: Development and Evaluation of Two Urine-Based Immunoassays for Detection of Leishmania donovani Infection in India. PLoS Negl. Trop. Dis., 10.","DOI":"10.1371\/journal.pntd.0005035"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"6697","DOI":"10.1128\/IAI.70.12.6697-6706.2002","article-title":"Characterization of Leishmania donovani Antigens Encapsulated in Liposomes That Induce Protective Immunity in BALB\/c Mice","volume":"70","author":"Afrin","year":"2002","journal-title":"Infect. Immun."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"6544","DOI":"10.1016\/j.vaccine.2007.05.042","article-title":"Leishmanial antigens in liposomes promote protective immunity and provide immunotherapy against visceral leishmaniasis via polarized Th1 response","volume":"25","author":"Bhowmick","year":"2007","journal-title":"Vaccine"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1304","DOI":"10.3201\/eid1707.100801","article-title":"Easy Test for Visceral Leishmaniasis and Post-Kala-azar Dermal Leishmaniasis","volume":"17","author":"Saha","year":"2011","journal-title":"Emerg. Infect. Dis."},{"key":"ref_20","first-page":"301","article-title":"A Native 51 kDa Leishmania Membrane Protein Revealed as a Novel Antigenic Candidate for Immuno-Diagnosis of Human VL and PKDL diseases","volume":"2","author":"Kamran","year":"2020","journal-title":"J. Cell. Immunol."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1281","DOI":"10.1093\/cid\/ciab435","article-title":"A novel antigen, otubain cysteine peptidase of Leishmania donovani improves serodiagnosis of visceral leishmaniasis and monitors treatment response","volume":"73","author":"Kamran","year":"2021","journal-title":"Clin. Infect. Dis."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.imlet.2020.01.005","article-title":"Evaluation of Leishmania infantum pyridoxal kinase protein for the diagnosis of human and canine visceral leishmaniasis","volume":"220","author":"Machado","year":"2020","journal-title":"Immunol. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Jones, N., Thomas, E.B., Brown, E., Dickens, N., Hammarton, T., and Mottram, J.C. (2014). Regulators of Trypanosoma brucei Cell Cycle Progression and Differentiation Identified Using a Kinome-Wide RNAi Screen. PLoS Pathog., 10.","DOI":"10.1371\/journal.ppat.1003886"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1016\/S0021-9258(19)52451-6","article-title":"Protein measurement with the Folin phenol reagent","volume":"193","author":"Lowry","year":"1951","journal-title":"J. Biol. Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5398","DOI":"10.1002\/sim.5959","article-title":"Bayesian meta-analysis of diagnostic tests allowing for imperfect reference standards","volume":"32","author":"Menten","year":"2013","journal-title":"Stat. Med."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"919","DOI":"10.1586\/eri.10.78","article-title":"Current diagnosis and treatment of visceral leishmaniasis","volume":"8","author":"Mondal","year":"2010","journal-title":"Expert Rev. Anti-Infect. Ther."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"873","DOI":"10.1038\/nrmicro1748","article-title":"Visceral leishmaniasis: What are the needs for diagnosis, treatment and control?","volume":"5","author":"Chappuis","year":"2007","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e00213-20","DOI":"10.1128\/JCM.00213-20","article-title":"Evaluation of Cysteine Protease C of Leishmania donovani in Comparison with Glycoprotein 63 and Elongation Factor 1\u03b1 for Diagnosis of Human Visceral Leishmaniasis and for Posttreatment Follow-Up Response","volume":"58","author":"Didwania","year":"2020","journal-title":"J. Clin. Microbiol."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/11\/2\/120\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:04:37Z","timestamp":1760133877000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/11\/2\/120"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,1,20]]},"references-count":28,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2022,2]]}},"alternative-id":["pathogens11020120"],"URL":"https:\/\/doi.org\/10.3390\/pathogens11020120","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,1,20]]}}}