Predictive value of cytomegalovirus DNA detection by polymerase chain reaction in blood and bronchoalveolar lavage in lung transplant patients.

BACKGROUND: Despite promising results, the efficacy of polymerase chain reaction (PCR) for clinical management of cytomegalovirus (CMV) infection in transplanted patients is still controversial.
METHODS: A prospective study of CMV detection, with concurrent shell vial cultures and PCR in blood and bronchoalveolar lavage (BAL), was conducted in 13 lung transplant recipients, monitored for 15 months (range: 1-42 months). CMV DNA was detected by PCR amplification of a 406-bp fragment in the Us region and a 290-bp fragment in the immediate early region of the viral genome.
RESULTS: When comparing PCR to viral culture, the sensitivity and specificity of CMV DNA detection were 100% and 65.7% in blood (n=122) and 100% and 75% in BAL (n=104). The positive and negative predictive values of PCR for a forthcoming diagnosis of CMV infection were 50% and 97% in blood, and 67% and 85% in BAL. Seventeen CMV infections were evaluated at the end of treatment: when PCR was still positive either in blood or BAL, CMV infection relapsed within 35+/-5 days; when PCR was negative, CMV infection relapsed after 142+/-57 days (P=0.01).
CONCLUSIONS: Negative CMV detection by PCR strongly advocates against a forthcoming CMV infection. PCR assay seems to be a good predictor for early recurrence of CMV infection, and would be useful for monitoring the response to antiviral therapy.