The presence of human cytomegalovirus
DNA was investigated in 103 unfixed endomyocardial biopsies, performed during the first 4 months in 17 heart transplant recipients by polymerase chain reaction. Results were correlated with human cytomegalovirus systemic
infection, as detected by the test for the viral lower matrix
phosphoprotein pp65 (antigenemia) and by polymerase chain reaction for
viral DNA in blood leukocytes (DNAemia). Three patients out of 17 did not develop
cytomegalovirus infection and 14 did: 5 had symptomatic disease treated with
ganciclovir and 9 developed
asymptomatic infection and were not treated.
Viral DNA was detected in 24 out of 103 biopsies (23%) from 13 patients: 5 with symptomatic
infection during the acute phase of disease (mean levels of pp65: 125+/-232 pp65 positive leukocytes/200,000 examined cells) and 8 patients with
asymptomatic infection when the mean antigenemia was 5+/-15/200,000 (4 patients) or when DNAnemia was present in the blood (4 patients). No histological evidence of
myocarditis was shown in
viral DNA-positive biopsies. No difference in acute rejection was found in
viral DNA-positive and
DNA-negative biopsy specimens in symptomatic and asymptomatic infected patients. Our experience suggests that during systemic symptomatic and asymptomatic
cytomegalovirus infection, polymerase chain reaction can detect a relatively frequent myocardial involvement, but this involvement is not associated with
myocarditis or with a higher incidence of acute rejection. THe presence of
viral DNA in myocardial biopsies can be a result of high
viremia, but it also can be due to low level of
viral DNA in circulating infected leukocytes. Polymerase chain reaction is the most sensitive method for cytomegalovirus
DNA detection in biopsies, but its results need to be evaluated together with morphology-preserving methods and systemic markers of
infection in order to make a correct diagnosis.