Rapid Detection of CMV-Specific DNA and mRNA by PCR in Immunocompromised Patients

Human cytomegalovirus (CMV) infections are the main cause of morbidity and mortality in immunodeficient patients, particularly bone-marrow and organ recipients as well as in human immunodeficiency virus type I (HIV-I) infected individuals. Depending on the type of high-risk group they belong to, more than 90% of HIV-I-positive patients may be CMV-seropositive, and disseminated CMV infections can be demonstrated in 93% of all cases at autopsy [1]. A major problem in diagnosing CMV and clarifying its pathomechanism arises from the latency of the disease. Acquisition of the virus usually leads to a latent infection. Investigations in bone marrow and blood recipients show that subpopulations of blood cells may be one site of latency. So far, however, nearly all attempts to isolate the virus from mononuclear cells of seropositive asymptomatic subjects have yielded negative results. Using the method of in situ hybridization Schrier and coworkers [2], however, reported that viral RNA was demonstrated more frequently in OKT4- than in OKT8-positive cells of seropositive individuals. Different results have been obtained in immunocompromised patients at the stage of viremia. Here, the virus can be cultured from monocytes and granulocytes [3], which, however, does not necessarily indicate the target of latent infection but may only be the result of unspecific phagocytotic activity.