Research Article Neopterin and CXCL-13 in Diagnosis and Follow-Up of Trypanosoma brucei gambiense Sleeping Sickness: Lessons from the Field in Angola Julien Bonnet , 1 Philippe Vignoles, 1 Natalia Tiberti, 2,3 Vatunga Gedeão, 4 Alexandre Hainard, 2 Natacha Turck , 2 Theophile Josenando, 4 Joseph M Ndung’u, 5 Jean-Charles Sanchez , 2 Bertrand Courtioux , 1 and Sylvie Bisser 1,6 1 Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, CNRS FR 3503 GEIST, University of Limoges, INSERM UMR1094 Tropical Neuroepidemiology, Limoges, France 2 Translational Biomarker Group, Department of Human Protein Sciences, University of Geneva, Geneva, Switzerland 3 Department of Infectious—Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy 4 Instituto de Combate e Controlo das Tripanossomiases (ICCT), Luanda, Angola 5 Foundation for Innovative New Diagnostics (FIND), Geneva, Switzerland 6 Pasteur Institute in French Guiana, 23 Boulevard Pasteur, 973006 Cayenne Cedex, French Guiana Correspondence should be addressed to Julien Bonnet; julien.bonnet@unilim.fr Received 24 April 2019; Revised 10 September 2019; Accepted 8 October 2019; Published 23 November 2019 Academic Editor: K.H. Mok Copyright © 2019 Julien Bonnet et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Human African Trypanosomiasis may become manageable in the next decade with fexinidazole. However, currently stage diagnosis remains difficult to implement in the field and requires a lumbar puncture. Our study of an Angolan cohort of T. b. gambiense-infected patients used other staging criteria than those recommended by the WHO. We compared WHO criteria (cell count and parasite identification in the CSF) with two biomarkers (neopterin and CXCL-13) which have proven potential to diagnose disease stage or relapse. Biological, clinical, and neurological data were analysed from a cohort of 83 patients. A neopterin concentration below 15.5 nmol/L in the CSF denoted patients with stage 1 disease, and a concentration above 60.31 nmol/L characterized patients with advanced stage 2 (trypanosomes in CSF and/or cytorachia higher than 20 cells) disease. CXCL-13 levels below 91.208 pg/mL denoted patients with stage 1 disease, and levels of CXCL-13 above 395.45 pg/mL denoted patients with advanced stage 2 disease. Values between these cut-offs may represent patients with intermediate stage disease. Our work supports the existence of an intermediate stage in HAT, and CXCL-13 and neopterin levels may help to characterize it. 1. Introduction It is hoped that sleeping sickness will become manageable within the next decade, as suggested by the WHO [1, 2]. In 2016, the number of patients with sleeping sickness has been reported as fewer than 4,000 but there are still unreported cases, and the estimate of actual cases is around 20,000 infected people in the remaining endemic countries in Africa. e availability of easy-to-use molecules such as fexinidazole (oral intake) will help to reduce the remaining burden of the disease [3, 4]. Pentamidine (for gambiense-HAT) remains the mole- cule indicated for the treatment of stage 1 of the disease. us, stage diagnosis is still necessary. Furthermore, fex- inidazole has so far only been used in the context of field trials. What will happen when it is used routinely? Moreover, the infection mechanism remains incompletely understood; the disease may reappear at cyclic intervals as chronically infected individuals without clinical signs of disease or animal reservoirs can lead to reemergence [5, 6]. Recently, the skin has been suggested as possible reservoir of latent infection, leading to relapse [7], and several authors have Hindawi BioMed Research International Volume 2019, Article ID 6070176, 9 pages https://doi.org/10.1155/2019/6070176