Improvement of an ultrasensitive human immunodeficiency virus type 1 real-time reverse transcriptase-polymerase chain reaction targeting the long terminal repeat region.
BACKGROUND
Human immunodeficiency virus Type 1 (HIV-1) assays applying nucleic acid testing (NAT) rely on HIV-1 sequence-specific primers and probes. Their hybridization can be limited or abolished by genetic polymorphisms occurring in the target sequence.


METHODS
Blood donations are routinely tested for HIV-1/2 antibodies and for HIV-1 RNA in our blood transfusion unit. Recently, HIV-1 RNA was undetectable with an established in-house real-time long terminal repeat (LTR) reverse transcriptase-polymerase chain reaction (RT-PCR) in two cases, whereas serologic assays were positive. The reason for this discrepancy was elucidated by sequencing of the NAT target region in the respective single donations. An improved primer was designed and tested on HIV-1 reference panels and blood donations to ensure reliable detection of HIV-1 RNA.


RESULTS
Direct sequencing of the target region, isolated from samples of two unrelated HIV-positive blood donors, revealed one and four mismatches in the hybridization domain of the forward primer, respectively. Both viruses belong to HIV-1 Subtype B. LTR RT-PCR with an additional forward primer was suitable for all strains of HIV-1 tested with high sensitivity.


CONCLUSIONS
Surveillance of HIV-1 genetic diversity is essentially required to continually evaluate its impact on performance of diagnostic and patient monitoring assays.
Edelmann
Anke
A
Institute of Virology Helmut-Ruska-Haus, Charité University Medicine Berlin, Berlin, Germany. anke.edelmann@charite.de
Kalus
Ulrich
U
Oltmann
Anke
A
Stein
Angela
A
Unbehaun
Anett
A
Drosten
Christian
C
Krüger
Detlev H
DH
Hofmann
Jörg
J
D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D001782:Blood Donors; D046148:Donor Selection; D014644:Genetic Variation; D015658:HIV Infections / Q000097:blood / Q000235:genetics; D016325:HIV Long Terminal Repeat; D015497:HIV-1; D006801:Humans; D008297:Male; D012367:RNA, Viral / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity
D000914:Antibodies, Viral; D012367:RNA, Viral