Usefulness of pp65 antigenemia for the early diagnosis of cytomegalovirus disease in patients with AIDS

An observational cohort study was performed to assess the effectiveness of a cytomegalovirus antigenemia (CMV-Ag) assay designed to predict clinical C MV disease in patients with AIDS, Eighty-six HIV-infected patients with CD4 + cell counts of <100/mm(3), positive CMV IgG, and no previous CMV disease were enrolled. Thirty-eight (44%) patients had at least one positive CMV an tigenemia test, ten of whom eventually developed CMV focal disease. CMV dis ease was diagnosed in 13 (15%) patients. The CMV antigenemia assay was posi tive in ten of these 13 patients. Using a cut-off value of five positive ce lls in every 150 000 leukocytes sampled, the CMV antigenemia assay had a po sitive predictive value of 89% and a negative predictive value of 94%. The median time from the first positive CMV antigenemia test to the onset of CM V disease was 102 days. CMV disease probability at 6 months in patients wit h a CMV antigenemia value greater than or equal to 5 was 77.8% versus 6% in patients with CMV antigenemia value <5 (log-rank test = 48.345; P < 0.001) . Several independent factors were associated with the development of CMV d isease: CMV antigenemia greater than or equal to 5 cells (hazard ratio: 20. 44), CD4+ count less than or equal to 25/mm(3) (HR: 3.12), and sexual trans mission of HIV infection (hazard ratio, 3.15). CMV antigenemia seems to be a good predictor of CMV disease in patients with AIDS.