title: Disparate detection outcomes for anti-HCV IgG and HCV RNA in dried blood spots.
abstract: Dried blood spots (DBS) expedite the collection, storage and shipping of blood samples, thereby facilitating large-scale serologic studies. We evaluated the sensitivity of anti-HCV IgG testing and HCV-RNA quantitation using freshly prepared and stored DBS derived from HCV-infected patients. Protocols for elution were optimized using DBS prepared from plasma of 52 HCV-infected persons and 51 uninfected persons (control DBS), then applied to DBS from 33 chronic hepatitis C patients that had been stored at -20°C for 5 years (stored DBS). Control and stored DBS, and their corresponding plasma, were processed for anti-HCV IgG testing using the VITROS chemiluminescence assay (CIA) and the HCV 3.0 enzyme immunoassay (EIA) (Ortho-Clinical Diagnostics), and for HCV RNA quantitation by quantitative (q) RT-PCR. HCV genotyping was conducted by nucleotide sequencing. The sensitivity of CIA and EIA in control DBS was 92% and 90%, respectively, compared to 100% and 97%, respectively, in stored DBS. The sensitivity of HCV RNA detection was 88% in control DBS, compared to 36% in stored DBS. Specificity was 100% for all the assays in both control and stored DBS. Genotypes 1, 2 and 3 were detected in 16 (62%), 6 (23.1%), and 4 (15.3%) samples, respectively. Sequences generated from DBS and their corresponding plasma samples were identical. Whereas the sensitivity of anti-HCV IgG detection in stored DBS was equivalent to that in recently prepared DBS, the sensitivity of HCV RNA detection was markedly lower in stored DBS compared to recently prepared DBS. Stored DBS may be reliably used for anti-HCV detection but for HCV-RNA-based testing freshly prepared DBS is preferable to stored DBS.
authors.affiliation: Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30329, USA.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Tejada-Strop
authors.affiliation: Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30329, USA. Electronic address: jqd6@cdc.gov.
authors.forename: Jan
authors.initials: J
authors.lastname: Drobeniuc
authors.affiliation: Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30329, USA.
authors.forename: Tonya
authors.initials: T
authors.lastname: Mixson-Hayden
authors.affiliation: Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30329, USA.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Forbi
authors.affiliation: Alaska Health and Social Services, 350 Main Street, Juneau, AK 99811, USA.
authors.forename: Ngoc-Thao
authors.initials: NT
authors.lastname: Le
authors.affiliation: Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30329, USA.
authors.forename: Lixia
authors.initials: L
authors.lastname: Li
authors.affiliation: Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30329, USA.
authors.forename: Joanne
authors.initials: J
authors.lastname: Mei
authors.affiliation: University of California San Francisco Medical Center, 513 Parnassus Ave., San Francisco, CA 94143, USA.
authors.forename: Norah
authors.initials: N
authors.lastname: Terrault
authors.affiliation: Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30329, USA.
authors.forename: Saleem
authors.initials: S
authors.lastname: Kamili
mesh_terms: D001769:Blood / Q000821:virology*; D003890:Desiccation / Q000379:methods*; D005838:Genotype; D016174:Hepacivirus / Q000145:classification / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D006526:Hepatitis C / Q000175:diagnosis; D018937:Hepatitis C Antibodies / Q000097:blood*; D006801:Humans; D007118:Immunoassay; D007074:Immunoglobulin G / Q000097:blood*; D012367:RNA, Viral / Q000097:blood*; D060888:Real-Time Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D013048:Specimen Handling / Q000379:methods*
chemical_list: D018937:Hepatitis C Antibodies; D007074:Immunoglobulin G; D012367:RNA, Viral
keywords: Blood specimen collection; Genotype; Hepatitis C antibodies; Molecular typing; Real-time polymerase chain reaction