Evaluation of a novel real-time PCR system for cytomegalovirus DNA quantitation on whole blood and correlation with pp65-antigen test in guiding pre-emptive antiviral treatment.
Successful pre-emptive anti-cytomegalovirus (CMV) therapy relies on sensitive, specific and reproducible tests for CMV detection. Real-time polymerase chain reaction (PCR) for CMV-DNA provides a superior reproducibility and sensitivity than pp65-antigenemia. Evaluation of a novel commercial real-time PCR for CMV-DNA associated with a fully automated DNA extraction from whole blood (WB) was performed, studying the correlation with pp65-antigenemia in guiding pre-emptive therapy. Analytical evaluation showed that PCR correctly quantitated CMV from 500 to 500,000copies/ml with a close correlation with expected values (r=0.999). Clinical evaluation on 375 consecutive WB samples from 48 infected patients (18 pre-emptively treated for pp65 values >/=50 positive cells) showed that according to pp65-antigenemia of 0, 1-10, 11-49 and >/=50 positive cells, median DNA levels were 3.7, 3.9, 4.6 and 5.6 log(10)copies/ml, respectively. According to existing pre-emptive treatment criteria based on pp65-antigenemia, receiver-operating curve analysis indicated 5.3log/ml (200,000genomes/ml) as the best CMV-DNA level to discriminate between patients requiring pre-emptive therapy and those who did not (positive predictive value: 91%; negative predictive value: 74%; sensitivity and specificity: 68 and 93%). In conclusion, real-time PCR provides reliable results for monitoring the developing of CMV infection, allowing for the definition of CMV-DNA thresholds associated with infection progress.
Microbiology Laboratory, Molinette Hospital, Turin, Italy.
Tiziano
T
Allice
Francesco
F
Cerutti
Fabrizia
F
Pittaluga
Silvia
S
Varetto
Alessandro
A
Franchello
Mauro
M
Salizzoni
Valeria
V
Ghisetti
D000998:Antiviral Agents / Q000627:therapeutic use; D003587:Cytomegalovirus / Q000302:isolation & purification*; D003586:Cytomegalovirus Infections / Q000188:drug therapy* / Q000821:virology*; D004279:DNA, Viral / Q000097:blood*; D006801:Humans; D010750:Phosphoproteins / Q000276:immunology; D016133:Polymerase Chain Reaction / Q000379:methods*; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D019562:Viral Load / Q000379:methods*; D014763:Viral Matrix Proteins / Q000276:immunology
D000998:Antiviral Agents; D004279:DNA, Viral; D010750:Phosphoproteins; D014763:Viral Matrix Proteins; C065418:cytomegalovirus matrix protein 65kDa