Polymerase chain reaction detection of cytomegalovirus DNA in peripheral blood leukocytes as a predictor of cytomegalovirus disease in HIV-infected patients.

OBJECTIVE: To describe and evaluate a polymerase chain reaction (PCR) method for early diagnosis and prompt management of cytomegalovirus (CMV) retinitis in HIV-infected patients.
METHODS: A total of 110 HIV-infected patients (Centers for Disease Control and Prevention stages II to IV) were sampled sequentially for isolation of CMV from peripheral blood leukocytes (PBL; n = 560) and for amplification of CMV DNA in PBL. Semiquantitative analysis of the PCR product was performed and each PCR-positive specimen was assigned a score between 1+ and 4+ (corresponding to four points on a standard curve of dilutions: 80, 800, 8000 and 80,000 CMV genome copies).
RESULTS: Levels of CMV DNA in blood increased with HIV infection stage. We focused on eight patients who developed one or more episodes of retinitis during longitudinal follow-up, in whom we found a strong correlation between viraemia, high PCR signal (3+ or 4+) (P < 0.0001) and clinical symptoms. Relapse was preceded by an increase in CMV DNA and resolution correlated with clearance of CMV DNA from blood.
CONCLUSIONS: Persistent high PCR levels always preceded virus isolation and may be the first indication of organ involvement and thus early treatment. PCR scores were consistently useful as indicators of drug efficacy and for monitoring of treatment.