Early diagnosis of CMV disease in HIV-infected individuals using the polymerase chain reaction.

Abstract

Human cytomegalovirus (CMV) is a herpesvirus that is responsible for significant morbidity and mortality in the setting of the acquired immunodeficiency syndrome (AIDS). The objective of this work was to devise a sensitive assay for the early diagnosis of CMV infection in HIV-infected individuals at highest risk of developing clinical CMV disease based on their CD4$\sp+$ T cell count and clinical status. A novel PCR assay was developed which can be applied to detect both latent and active CMV DNA in appropriate clinical specimens. Sensitivity and specificity were established in comparison with conventional diagnostic tests, including cell culture and serology. Other herpesvirus DNA (EBV, HSV-1, HSV-2) and bacterial (Neisseria gonorrhoeae) DNA were used to confirm the specificity of the assay. A sensitive, specific and semi-quantitative PCR protocol was applied to detect both latent and active CMV DNA in appropriate clinical specimens. We hypothesized that selective PCR in neutrophils could allow the specific detection of actively replicating virions. Blood samples routinely submitted for CMV culture were shown to be acceptable for CMV PCR. Of 25 patients studied (HIV seropositive, CD4 100/$\mu$l), 9 had CMV DNA in their circulating neutrophils, while only one had a positive CMV blood culture. Six out of nine (including the culture positive individual) had CMV retinitis, while other 3 had a clinical illness compatible with CMV. None of the 16 patients with negative neutrophil CMV PCR results had any evidence of clinical disease attributable to CMV. Follow-up testing of 6 patients with positive baseline PCR result and treated appropriately for CMV showed negative PCR results at 1-3 months. This PCR test may be useful in the diagnosis and follow-up of HIV-infected individuals at risk of CMV disease. (Abstract shortened by UMI.)