Quantitative cytomegalovirus DNA level in the blood and its relationship to cytomegalovirus retinitis in patients with acquired immune deficiency syndrome.

OBJECTIVE: A pilot study was performed to determine whether relationships exist between changes in a quantitative solution hybridization assay for cytomegalovirus (CMV) DNA in the blood and development of CMV retinitis, development of nonocular CMV disease, or reactivation of pre-existing CMV retinitis lesions.

DESIGN: Observational case series.

PARTICIPANTS: Two groups of human immunodeficiency virus-infected patients: 10 CMV antibody-positive patients with CD4+ T-lymphocyte counts of less than 50 ml and no CMV disease at baseline and 11 patients with CMV retinitis but no extraocular CMV disease at baseline.

INTERVENTION: Quantitative changes in leukocyte-associated CMV DNA levels were observed over time. Anti-CMV therapies were based on clinical findings only.

MAIN OUTCOME MEASURES: Development of CMV end-organ disease or change in activity of pre-existing CMV retinitis lesions was measured.

RESULTS: Among patients with no CMV disease at baseline, four had CMV disease develop during follow-up (three cases of CMV retinitis, one case of presumed CMV esophagitis); all had CMV DNA levels greater than 5000 genomes/ml before the onset of CMV disease. The remaining six patients had levels less than 5000 genomes/ml throughout follow-up (P = 0.05). Among patients with CMV retinitis at baseline, all whose CMV DNA blood levels rose more than tenfold had extraocular CMV disease or reactivation of CMV retinitis develop. Raised CMV DNA blood levels were not seen in every patient with clinical reactivation of CMV retinitis.

CONCLUSION: Elevated or rising CMV DNA blood levels appear to be associated with the development of CMV disease in individuals with low CD4+ T-lymphocyte counts. In patients with CMV retinitis, rising levels appear to be associated with the development of extraocular CMV disease or reactivation of CMV retinitis. Conversely, reactivation of CMV retinitis also may occur in the absence of changes in CMV DNA blood levels. Further studies are warranted to determine whether changes in CMV blood levels can be used as a guide for preemptive therapy to prevent reactivation of CMV retinitis lesions or to help choose between local and systemic therapy for management of reactivations.