title: Efficient evaluation of humoral immune responses by the use of serum pools.
abstract: Collection and testing of individual serum samples are often used in research to gain knowledge about e.g. the humoral response against bacteria or virus. This is a valid but time-consuming method and might be a waste of valuable serum samples for inefficient research. So far, no study has considered using serum pools as a quick and efficient screening method to confirm or deny hypotheses.
  
  
  
  We created serum pools from four different patient groups (systemic lupus erythematosus n=85, rheumatoid arthritis n=77, Sjögren's syndrome n=91, systemic sclerosis n=66) and one healthy control group (n=67). Each serum pool was analyzed using three well-known immunoassays: enzyme-linked immunosorbent assay (ELISA), line blot, and immunofluorescence microscopy (anti-nuclear antibody (ANA) screening). The presence of Epstein-Barr virus (EBV) EA/D-, EBNA-1-, VCA p23-, and gp350-directed antibodies was used to validate serum pools as an efficient tool for further investigations by comparison to previous findings in this area.
  
  
  
  The presence of EBV EA/D-, EBNA-1-, VCA p23-, and gp350-directed antibodies in each pool was consistent within the obtained ELISA and line blot results, as increased titers of IgG against the four antigens were found in all patient serum pools and also in individual sera regarding gp350. These results correspond to previous findings on individual samples from patients with these diseases. The presence of ANAs was observed in all four patient serum pools and not in the HC pool by both line blots and immunofluorescence microscopy, which corresponds with the expectations and further corroborate the application of serum pools for screenings.
  
  
  
  We developed and validated the use of serum pools that reliably and rapidly can confirm or deny hypotheses, which enables a more efficient research concentrating on the most evident factors.
authors.affiliation: Department of Autoimmunology and Biomarkers, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Louise
authors.initials: L
authors.lastname: Sternbæk
authors.affiliation: Department of Autoimmunology and Biomarkers, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: Anette H
authors.initials: AH
authors.lastname: Draborg
authors.affiliation: Copenhagen Lupus & Vasculitis Clinic, Center for Rheumatology and Spine Disease, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Christoffer T
authors.initials: CT
authors.lastname: Nielsen
authors.affiliation: Copenhagen Lupus & Vasculitis Clinic, Center for Rheumatology and Spine Disease, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Søren
authors.initials: S
authors.lastname: Jacobsen
authors.affiliation: Department of Dermatology, Copenhagen University Hospital, Bispebjerg, Copenhagen, Denmark.
authors.forename: Line V
authors.initials: LV
authors.lastname: Iversen
authors.affiliation: Department of Clinical Immunology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark.
authors.forename: Lone
authors.initials: L
authors.lastname: Troelsen
authors.affiliation: Department of Rheumatology, Lund University, Skåne University Hospital, Malmö, Sweden.
authors.forename: Elke
authors.initials: E
authors.lastname: Theander
authors.affiliation: Department of Autoimmunology and Biomarkers, Statens Serum Institut, Copenhagen, Denmark. Electronic address: gh@ssi.dk.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Houen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D015415:Biomarkers / Q000097:blood*; D036022:Capsid Proteins / Q000276:immunology; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D020031:Epstein-Barr Virus Infections / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D019309:Epstein-Barr Virus Nuclear Antigens / Q000276:immunology; D005260:Female; D006801:Humans; D056724:Immunity, Humoral; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000097:blood*; D008180:Lupus Erythematosus, Systemic / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D044967:Serum / Q000276:immunology*; D012859:Sjogren's Syndrome / Q000097:blood* / Q000175:diagnosis / Q000276:immunology; D014763:Viral Matrix Proteins / Q000276:immunology; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D015415:Biomarkers; D036022:Capsid Proteins; D019309:Epstein-Barr Virus Nuclear Antigens; C041788:Epstein-Barr viral capsid antigen; C083204:Epstein-Barr virus early antigen diffuse component; C034059:GP 300-350, Epstein-Barr virus; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D014763:Viral Matrix Proteins; C417029:EBV-encoded nuclear antigen 1
keywords: ELISA; Line blot; Screening; Serology; Serum pools