NAT for HBV and anti-HBc testing increase blood safety.
BACKGROUND
Routine HBV PCR screening of blood donations to our institutes was introduced in January 1997 to complete the NAT screening program for transfusion-relevant viruses. Testing was successively extended to customer transfusion services with a total of 1,300,000 samples tested per year.


METHODS
Minipools of 96 blood donation samples were formed by automatic pipettors. HBsAg-reactive samples were included. HBV particles were enriched from the minipools by centrifugation. Conventional and in-house TaqMan PCRs were successively applied for HBV amplification. Sensitivity reached 1000 genome equivalents per mL for each individual donation. Confirmatory single-sample and single-sample enrichment PCRs were established with sensitivities of 300 and 5 to 10 genome equivalents per mL, respectively.


RESULTS
After screening of 3.6 million donor samples, 6 HBV PCR-positive, HBsAg-negative donations were identified. Two samples were from infected donors who had not seroconverted and four were from chronic anti-HBc-positive low-level HBV carriers. Retesting by single-sample PCR of 432 samples confirmed positive for HBsAg identified 37 donations that were negative in minipool PCR. Donor-directed look-back procedures indicated that no infected donor who had not yet seroconverted was missed by minipool PCR. However, recipient-directed look-back procedures revealed two anti-HBc-positive recipients of HBsAg-negative minipool PCR-negative, anti-HBc-positive and single-sample PCR-positive blood components. After testing randomly selected 729 HBsAg-negative minipool PCR-negative, anti-HBc-positive donors by single-sample enrichment PCR, 7 were identified with < or = 10 HBV particles per mL of donor plasma.


CONCLUSIONS
Minipool PCR testing after virus enrichment was sensitive enough to identify HBsAg-negative donors who had seroconverterd and HBsAg-negative, anti-HBc-positive chronic HBV carriers. HBV NAT in conjunction with anti-HBc screening would reduce the residual risk of transfusion-transmitted HBV infection.
Roth
W Kurt
WK
Institute of Transfusion Medicine and Immunohematology German Red Cross, Hesse, Frankfurt.
Weber
Marijke
M
Petersen
Detlev
D
Drosten
Christian
C
Buhr
Sylvia
S
Sireis
Walid
W
Weichert
Wolfgang
W
Hedges
Doris
D
Seifried
Erhard
E
D000914:Antibodies, Viral / Q000097:blood; D001769:Blood / Q000821:virology; D001771:Blood Banks / Q000592:standards; D001782:Blood Donors; D001803:Blood Transfusion / Q000592:standards; D003257:Consumer Product Safety; D004279:DNA, Viral / Q000097:blood; D005858:Germany; D006509:Hepatitis B / Q000175:diagnosis / Q000635:transmission; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D006515:Hepatitis B virus / Q000235:genetics*; D006801:Humans; D008403:Mass Screening / Q000379:methods; D021141:Nucleic Acid Amplification Techniques / Q000592:standards*; D012680:Sensitivity and Specificity; D000094902:Blood Banking / Q000379:methods
D000914:Antibodies, Viral; D004279:DNA, Viral; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens