QUANTIFICATION OF HUMAN CYTOMEGALOVIRUS DNA IN PERIPHERAL-BLOOD POLYMORPHONUCLEAR LEUKOCYTES OF IMMUNOCOMPROMISED PATIENTS BY THE POLYMERASE CHAIN-REACTION

Human cytomegalovirus (HCMV) DNA amplification by the polymerase chain reaction (PCR) was utilized previously for successful monitoring of H CMV infections in immunocompromised patients. However, analysis of an extended series of clinical samples revealed the relatively frequent p resence of PCR inhibitors. Hence, the need for availability of an inte rnal control of the reaction allowing identification of false negative results. Similarly, an internal standard appeared necessary for quant ification of viral DNA in clinical samples. For this purpose, we const ructed a recombinant DNA molecule which could be amplified by the same set of primers used for HCMV DNA amplification. Coamplification of th e recombinant DNA molecule and clinical samples proved to be a simple and reliable method for verifying sample competence for amplification. In addition, coamplification of serial known amounts of the same mole cule, used as internal standard, and test sample, allowed quantificati on of viral DNA in polymorphonuclear leukocyte samples. Quantitative m onitoring of HCMV infection and antiviral treatment may provide critic al indications as to whether and when to initiate or discontinue antiv iral treatment in immunocompromised patients with systemic HCMV infect ions.