title: Evaluation of dried blood spot protocols with the Bio-Rad GS HIV Combo Ag/Ab EIA and Geenius™ HIV 1/2 Supplemental Assay.
abstract: FDA-approved antigen/antibody combo and HIV-1/2 differentiation supplemental tests do not have claims for dried blood spot (DBS) use. We compared two DBS-modified protocols, the Bio-Rad GS HIV Combo Ag/Ab (BRC) EIA and Geenius™ HIV-1/2 (Geenius) Supplemental Assay, to plasma protocols and evaluated them in the CDC/APHL HIV diagnostic algorithm.
  
  
  
  BRC-DBS p24 analytical sensitivity was calculated from serial dilutions of p24. DBS specimens included 11 HIV-1 seroconverters, 151 HIV-1-positive individuals, including 20 on antiretroviral therapy, 31 HIV-2-positive and one HIV-1/HIV-2-positive individuals. BRC-reactive specimens were tested with Geenius using the same DBS eluate. Matched plasma specimens were tested with BRC, an IgG/IgM immunoassay and Geenius. DBS and plasma results were compared using the McNemar's test. A DBS-algorithm applied to 348 DBS from high-risk individuals who participated in surveillance was compared to HIV status based on local testing algorithms.
  
  
  
  BRC-DBS detects p24 at a concentration 18 times higher than in plasma. In seroconverters, BRC-DBS detected more infections than the IgG/IgM immunoassay in plasma (p=0.0133), but fewer infections than BRC-plasma (p=0.0133). In addition, the BRC/Geenius-plasma algorithm identified more HIV-1 infections than the BRC/Geenius-DBS algorithm (p=0.0455). The DBS protocols correctly identified HIV status for established HIV-1 infections, including those on therapy, HIV-2 infections, and surveillance specimens.
  
  
  
  The DBS protocols exhibited promising performance and allowed rapid supplemental testing. Although the DBS algorithm missed some early infections, it showed similar results when applied to specimens from a high-risk population. Implementation of a DBS algorithm would benefit testing programs without capacity for venipuncture.
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.affiliation: Bio-Rad Laboratories, Redmond, WA, USA.
authors.forename: Geoff
authors.initials: G
authors.lastname: Davis
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: LiXia
authors.initials: L
authors.lastname: Li
authors.affiliation: Bio-Rad Laboratories, Redmond, WA, USA.
authors.forename: M Kathleen
authors.initials: MK
authors.lastname: Shriver
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Joanne
authors.initials: J
authors.lastname: Mei
authors.affiliation: Wadsworth Center, New York State Department of Health, Albany, NY, USA.
authors.forename: Linda M
authors.initials: LM
authors.lastname: Styer
authors.affiliation: Wadsworth Center, New York State Department of Health, Albany, NY, USA.
authors.forename: Monica M
authors.initials: MM
authors.lastname: Parker
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Amanda
authors.initials: A
authors.lastname: Smith
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Paz-Bailey
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Ethridge
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Wesolowski
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: S Michele
authors.initials: SM
authors.lastname: Owen
authors.affiliation: Centers for Disease Control and Prevention, Atlanta, GA, USA. Electronic address: svm6@cdc.gov.
authors.forename: Silvina
authors.initials: S
authors.lastname: Masciotra
mesh_terms: D015492:AIDS Serodiagnosis; D000465:Algorithms; D059788:Dried Blood Spot Testing / Q000295:instrumentation / Q000379:methods; D062665:Epidemiological Monitoring; D015483:HIV Antibodies / Q000097:blood; D015488:HIV Antigens / Q000097:blood / Q000276:immunology; D015658:HIV Infections / Q000097:blood / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000276:immunology; D015498:HIV-2 / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques; D012367:RNA, Viral / Q000097:blood; D011933:Reagent Kits, Diagnostic; D012307:Risk Factors; D012680:Sensitivity and Specificity
chemical_list: D015483:HIV Antibodies; D015488:HIV Antigens; D012367:RNA, Viral; D011933:Reagent Kits, Diagnostic
keywords: DBS testing; HIV diagnostics; Surveillance