PRISM hepatitis B surface antigen detection of hepatits B virus minipool nucleic acid testing yield samples.
BACKGROUND
Hepatitis B virus (HBV) residual risk has been estimated at 1:63,000-1:205,000 and introduction of more sensitive serological tests and nucleic acid testing (NAT) would reduce that risk. Sensitivity of the recently licensed Abbott PRISM hepatitis B surface antigen (HBsAg) CLIA and minipool (MP) HBV NAT has been described as comparable and thus the need for HBV NAT has not been compelling. In this study, eight samples identified as yield samples with MP HBV NAT were tested using the PRISM test.


METHODS
Seven samples were identified using the Roche COBAS AmpliScreen HBV test and one additional sample was obtained from the clinical trial for the Roche cobas TaqScreen MPX test. Each of these samples was reactive by MP HBV NAT and nonreactive for HBsAg using one of three licensed enzyme immunoassay (EIA) tests. After licensure of the PRISM HBsAg, aliquots were tested with this assay, and DNA quantitation and genotyping were repeated where sample volume permitted.


RESULTS
Three samples (2000, 2300, and 61,000 copies/mL) produced reactive results with PRISM. Four samples with viral loads less than 300 copies per mL produced nonreactive results. One sample, originally quantitated at 37,000 copies per mL (but 3850 copies/mL in repeat testing) was also nonreactive by PRISM. Genotyping of this sample indicated a type C genotype with no mutations.


CONCLUSIONS
Adding serological sensitivity of PRISM CLIA reduced the NAT yield from the original 1: 385,555 to 1:610,488. However, MP HBV NAT still provides additional sensitivity over CLIA, even for a donation with a viral load of almost 4000 copies per mL.
Linauts
Sandy
S
Blood Service Laboratories, Seattle, Washington 98104, USA. SandyL@psbc.org
Saldanha
John
J
Strong
D Michael
DM
D001782:Blood Donors; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005838:Genotype; D006509:Hepatitis B / Q000097:blood / Q000175:diagnosis / Q000821:virology; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006515:Hepatitis B virus / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D012680:Sensitivity and Specificity; D017422:Sequence Analysis, DNA; D019562:Viral Load
D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens