BACKGROUND: The interpretation of "indeterminate" results of the recombinant immunoblot assay (RIBA) is a particularly sensitive issue for Transfusion Services, and donors with such a serological condition require long-term follow-up. MATERIALS AND METHODS: In the Immunohaematology and Transfusion Medicine Division of Umberto I University Hospital (Rome, Italy), 102,979 donor blood units were screened for hepatitis C virus (HCV) antibodies by enzyme-linked immunosorbent assay (ELISA) over a 5-year period (01.01.2000 - 31.12.2004). Since 24.10.2001, HCV-RNA testing was added. All samples repeatedly reactive by ELISA were then submitted to a HCV confirmatory assay (RIBA). RESULTS: Among the 102,979 donors we found 271 positive to HCV ELISA testing. The results of the RIBA assay for these donors were negative in 178 (65.7%) cases, positive in 28 (10.3%) and indeterminate in 65 (24.0%). Of the 65 subjects with an indeterminate pattern, 24 completed a sufficient follow-up (median 25 months; range, 6 - 52), during which some (n = 8; 33%) converted to a negative status, some (n = 16; 67%) maintained their reactivity pattern, but none became seropositive for HCV. CONCLUSIONS: The HCV-RIBA indeterminate status may indicate either a non-specific reaction (false positive) or a real pre-existing or initial infection and does not, therefore, enable a prediction of outcome. The use of HCV genomic assays (nucleic acid amplification testing), which are more specific than antibody-based assays (ELISA, RIBA), therefore improves HCV blood donor testing by allowing an accurate interpretation of such primary assays.
BACKGROUND: The interpretation of "indeterminate" results of the recombinant immunoblot assay (RIBA) is a particularly sensitive issue for Transfusion Services, and donors with such a serological condition require long-term follow-up. MATERIALS AND METHODS: In the Immunohaematology and Transfusion Medicine Division of Umberto I University Hospital (Rome, Italy), 102,979 donor blood units were screened for hepatitis C virus (HCV) antibodies by enzyme-linked immunosorbent assay (ELISA) over a 5-year period (01.01.2000 - 31.12.2004). Since 24.10.2001, HCV-RNA testing was added. All samples repeatedly reactive by ELISA were then submitted to a HCV confirmatory assay (RIBA). RESULTS: Among the 102,979 donors we found 271 positive to HCV ELISA testing. The results of the RIBA assay for these donors were negative in 178 (65.7%) cases, positive in 28 (10.3%) and indeterminate in 65 (24.0%). Of the 65 subjects with an indeterminate pattern, 24 completed a sufficient follow-up (median 25 months; range, 6 - 52), during which some (n = 8; 33%) converted to a negative status, some (n = 16; 67%) maintained their reactivity pattern, but none became seropositive for HCV. CONCLUSIONS: The HCV-RIBA indeterminate status may indicate either a non-specific reaction (false positive) or a real pre-existing or initial infection and does not, therefore, enable a prediction of outcome. The use of HCV genomic assays (nucleic acid amplification testing), which are more specific than antibody-based assays (ELISA, RIBA), therefore improves HCV blood donor testing by allowing an accurate interpretation of such primary assays.
Authors: Mohamed Abdel-Hamid; Mai El-Daly; Sherif El-Kafrawy; Nabiel Mikhail; G Thomas Strickland; Alan D Fix Journal: J Clin Microbiol Date: 2002-05 Impact factor: 5.948
Authors: J M Lemaire; A M Courouce; C Defer; F Bouchardeau; J Coste; O Agulles; J F Cantaloube; V Barlet; F Barin Journal: Transfusion Date: 2000-07 Impact factor: 3.157
Authors: L A Kondili; P Chionne; A Costantino; U Villano; C Lo Noce; F Pannozzo; A Mele; S Giampaoli; M Rapicetta Journal: Gut Date: 2002-05 Impact factor: 23.059
Authors: L B Seeff; F B Hollinger; H J Alter; E C Wright; C M Cain; Z J Buskell; K G Ishak; F L Iber; D Toro; A Samanta; R L Koretz; R P Perrillo; Z D Goodman; R G Knodell; G Gitnick; T R Morgan; E R Schiff; S Lasky; C Stevens; R Z Vlahcevic; E Weinshel; T Tanwandee; H J Lin; L Barbosa Journal: Hepatology Date: 2001-02 Impact factor: 17.425
Authors: L Simonsen; J Buffington; C N Shapiro; R C Holman; T W Strine; B J Grossman; A E Williams; L B Schonberger Journal: Am J Epidemiol Date: 1995-06-01 Impact factor: 4.897