Quantitative evaluation of cytomegalovirus DNA in infantile hepatitis

We used a PCR method to develop a diagnostic assay for the detection of cyt omegalovirus (CMV) DNA in infantile hepatitis, which has been suggested to be associated with CMV infection. CMV DNA was detected in 25 (58.1%) of 43 patients with elevated serum alanine aminotransferase (ALT) levels but no j aundice, and no hepatitis B or C as assessed by conventional PCR. None of t he samples from 97 healthy infants tested positive for CMV DNA. We assayed CMV DNA quantitatively in blood using a real-time PCR system that allowed r eproducible detection of at least 10 copies of CMV DNA. When 1 mug of DNA f rom each blood sample was used in this system, a good correlation was obtai ned between the calculated and measured copy numbers of CMV DNA. This syste m detected CMV DNA in 29 patients (67.4%) with liver dysfunction. Serial st udies in patients with liver dysfunction revealed that CMV DNA copy number decreased, ultimately to below 10, as the ALT levels normalized. In contras t, no CMV DNA copies were detectable by the real-time system in any of the samples from control subjects. These results highlight the usefulness of de tecting CMV DNA in the diagnosis of infantile hepatitis and indicate that t he real-time quantitative PCR assay may be a valuable tool for monitoring C MV-associated infantile hepatitis.