title: Immunoepidemiological profiling of onchocerciasis patients reveals associations with microfilaria loads and ivermectin intake on both individual and community levels.
abstract: Mass drug administration (MDA) programmes against Onchocerca volvulus use ivermectin (IVM) which targets microfilariae (MF), the worm's offspring. Most infected individuals are hyporesponsive and present regulated immune responses despite high parasite burden. Recently, with MDA programmes, the existence of amicrofilaridermic (a-MF) individuals has become apparent but little is known about their immune responses. Within this immunoepidemiological study, we compared parasitology, pathology and immune profiles in infection-free volunteers and infected individuals that were MF(+) or a-MF. The latter stemmed from villages in either Central or Ashanti regions of Ghana which, at the time of the study, had received up to eight or only one round of MDA respectively. Interestingly, a-MF patients had fewer nodules and decreased IL-10 responses to all tested stimuli. On the other hand, this patient group displayed contrary IL-5 profiles following in vitro stimulation or in plasma and the dampened response in the latter correlated to reduced eosinophils and associated factors but elevated neutrophils. Furthermore, multivariable regression analysis with covariates MF, IVM or the region (Central vs. Ashanti) revealed that immune responses were associated with different covariates: whereas O. volvulus-specific IL-5 responses were primarily associated with MF, IL-10 secretion had a negative correlation with times of individual IVM therapy (IIT). All plasma parameters (eosinophil cationic protein, IL-5, eosinophils and neutrophils) were highly associated with MF. With regards to IL-17 secretion, although no differences were observed between the groups to filarial-specific or bystander stimuli, these responses were highly associated with the region. These data indicate that immune responses are affected by both, IIT and the rounds of IVM MDA within the community. Consequently, it appears that a lowered infection pressure due to IVM MDA may affect the immune profile of community members even if they have not regularly participated in the programmes.
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Arndts
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Specht
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR), Kumasi, Ghana ; Faculty of Allied Health Sciences and School of Medical Sciences of Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Alexander Y
authors.initials: AY
authors.lastname: Debrah
authors.affiliation: Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom.
authors.forename: Francesca
authors.initials: F
authors.lastname: Tamarozzi
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany ; Institute of Medical Biometry, Informatics and Epidemiology (IMBIE), University Hospital Bonn, Bonn, Germany.
authors.forename: Ute
authors.initials: U
authors.lastname: Klarmann Schulz
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Mand
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR), Kumasi, Ghana.
authors.forename: Linda
authors.initials: L
authors.lastname: Batsa
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kwarteng
authors.affiliation: Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Taylor
authors.affiliation: Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR), Kumasi, Ghana ; Faculty of Allied Health Sciences and School of Medical Sciences of Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: Ohene
authors.initials: O
authors.lastname: Adjei
authors.affiliation: UMR 7245 MCAM MNHN CNRS, Museum National d'Histoire Naturelle, Paris, France.
authors.forename: Coralie
authors.initials: C
authors.lastname: Martin
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Layland
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Bonn, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Hoerauf
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood; D000977:Antiparasitic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D015331:Cohort Studies; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D007559:Ivermectin / Q000008:administration & dosage* / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009854:Onchocerca / Q000276:immunology*; D009855:Onchocerciasis / Q000453:epidemiology* / Q000276:immunology*; D059208:Parasite Load; D055815:Young Adult
chemical_list: D000909:Antibodies, Helminth; D000977:Antiparasitic Agents; D016207:Cytokines; D007559:Ivermectin