title: Diagnosis of trypanosomatid infections: targeting the spliced leader RNA.
abstract: Trypanosomatids transcribe their genes in large polycistronic clusters that are further processed into mature mRNA molecules by trans-splicing. During this maturation process, a conserved spliced leader RNA (SL-RNA) sequence of 39 bp is physically linked to the 5' end of the pre-mRNA molecules. Trypanosomatid infections cause a series of devastating diseases in man (sleeping sickness, leishmaniasis, Chagas disease) and animals (nagana, surra, dourine). Here, we investigated the SL-RNA molecule for its diagnostic potential using reverse transcription followed by real-time PCR. As a model, we used Trypanosoma brucei gambiense, which causes sleeping sickness in west and central Africa. We showed that the copy number of the SL-RNA molecule in one single parasitic cell is at least 8600. We observed a lower detection limit of the SL-RNA assay in spiked blood samples of 100 trypanosomes per milliliter of blood. We also proved that we can detect the trypanosome's SL-RNA in the blood of sleeping sickness patients with a sensitivity of 92% (95% CI, 78%-97%) and a specificity of 96% (95% CI, 86%-99%). The SL-RNA is thus an attractive new molecular target for next-generation diagnostics in diseases caused by trypanosomatids.
authors.affiliation: Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium.
authors.forename: Pablo
authors.initials: P
authors.lastname: González-Andrade
authors.affiliation: National Sleeping Sickness Control Program, Ministry of Health and Public Hygiene, Conakry, Guinea.
authors.forename: Mamady
authors.initials: M
authors.lastname: Camara
authors.affiliation: International Center for Development Research on Aging in Sub-Humid Areas (CIRDES), Bobo-Dioulasso, Burkina Faso.
authors.forename: Hamidou
authors.initials: H
authors.lastname: Ilboudo
authors.affiliation: Institute of Research for Development, Mixed Research Unit IRD-CIRAD 177, Montpellier, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Bucheton
authors.affiliation: International Center for Development Research on Aging in Sub-Humid Areas (CIRDES), Bobo-Dioulasso, Burkina Faso; Institute of Research for Development, Mixed Research Unit IRD-CIRAD 177, Montpellier, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Jamonneau
authors.affiliation: Biomedical Sciences Department, Institute of Tropical Medicine, Antwerp, Belgium. Electronic address: sdeborggraeve@itg.be.
authors.forename: Stijn
authors.initials: S
authors.lastname: Deborggraeve
mesh_terms: D006801:Humans; D057230:Limit of Detection; D016053:RNA, Protozoan / Q000097:blood / Q000235:genetics / Q000302:isolation & purification*; D020038:RNA, Spliced Leader / Q000097:blood / Q000235:genetics / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D048348:Reverse Transcription; D014347:Trypanosoma brucei gambiense / Q000235:genetics / Q000302:isolation & purification*; D014353:Trypanosomiasis, African / Q000097:blood / Q000175:diagnosis* / Q000469:parasitology
chemical_list: D016053:RNA, Protozoan; D020038:RNA, Spliced Leader