title: Multivariable Regression Analysis in Schistosoma mansoni-Infected Individuals in the Sudan Reveals Unique Immunoepidemiological Profiles in Uninfected, egg+ and Non-egg+ Infected Individuals.
abstract: In the Sudan, Schistosoma mansoni infections are a major cause of morbidity in school-aged children and infection rates are associated with available clean water sources. During infection, immune responses pass through a Th1 followed by Th2 and Treg phases and patterns can relate to different stages of infection or immunity.
  
  
  
  This retrospective study evaluated immunoepidemiological aspects in 234 individuals (range 4-85 years old) from Kassala and Khartoum states in 2011. Systemic immune profiles (cytokines and immunoglobulins) and epidemiological parameters were surveyed in n = 110 persons presenting patent S. mansoni infections (egg+), n = 63 individuals positive for S. mansoni via PCR in sera but egg negative (SmPCR+) and n = 61 people who were infection-free (Sm uninf). Immunoepidemiological findings were further investigated using two binary multivariable regression analysis.
  
  
  
  Nearly all egg+ individuals had no access to latrines and over 90% obtained water via the canal stemming from the Atbara River. With regards to age, infection and an egg+ status was linked to young and adolescent groups. In terms of immunology, S. mansoni infection per se was strongly associated with increased SEA-specific IgG4 but not IgE levels. IL-6, IL-13 and IL-10 were significantly elevated in patently-infected individuals and positively correlated with egg load. In contrast, IL-2 and IL-1β were significantly lower in SmPCR+ individuals when compared to Sm uninf and egg+ groups which was further confirmed during multivariate regression analysis.
  
  
  
  Schistosomiasis remains an important public health problem in the Sudan with a high number of patent individuals. In addition, SmPCR diagnostics revealed another cohort of infected individuals with a unique immunological profile and provides an avenue for future studies on non-patent infection states. Future studies should investigate the downstream signalling pathways/mechanisms of IL-2 and IL-1β as potential diagnostic markers in order to distinguish patent from non-patent individuals.
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.|Department of Parasitology and Immunology, College of Medical Laboratory Science, Sudan University of Science and Technology, Khartoum, Sudan.
authors.forename: Tayseer Elamin Mohamed
authors.initials: TE
authors.lastname: Elfaki
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.
authors.forename: Kathrin
authors.initials: K
authors.lastname: Arndts
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Wiszniewsky
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ritter
authors.affiliation: Animal Resources Research Corporation, Ministry of Livestock, Fisheries and Rangelands, Khartoum, Sudan.
authors.forename: Ibtisam A
authors.initials: IA
authors.lastname: Goreish
authors.affiliation: Department of Parasitology and Immunology, College of Medical Laboratory Science, Sudan University of Science and Technology, Khartoum, Sudan.
authors.forename: Misk El Yemen A
authors.initials: Mel Y
authors.lastname: Atti El Mekki
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Arriens
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Pfarr
authors.affiliation: Institute of Medical Biometry, Informatics and Epidemiology (IMBIE), University Hospital of Bonn, Bonn, Germany.
authors.forename: Rolf
authors.initials: R
authors.lastname: Fimmers
authors.affiliation: School of Biology, University of Nottingham, Nottingham, United Kingdom.
authors.forename: Mike
authors.initials: M
authors.lastname: Doenhoff
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.|German Centre for Infection Research (DZIF), partner site, Bonn-Cologne, Bonn, Germany.
authors.forename: Achim
authors.initials: A
authors.lastname: Hoerauf
authors.affiliation: Institute of Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital of Bonn, Bonn, Germany.|German Centre for Infection Research (DZIF), partner site, Bonn-Cologne, Bonn, Germany.
authors.forename: Laura E
authors.initials: LE
authors.lastname: Layland
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D000947:Antigens, Helminth / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D015801:Helminth Proteins / Q000276:immunology*; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007074:Immunoglobulin G / Q000097:blood; D007378:Interleukins / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010063:Ovum; D012044:Regression Analysis; D012189:Retrospective Studies; D012499:Sanitation; D012550:Schistosoma mansoni / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000453:epidemiology* / Q000276:immunology*; D013397:Sudan / Q000453:epidemiology; D014881:Water Supply; D055815:Young Adult
chemical_list: D000947:Antigens, Helminth; D015801:Helminth Proteins; D007074:Immunoglobulin G; D007378:Interleukins; D007073:Immunoglobulin E