Background: Whether an association exists between infection with beta -herpesviruses and connective tissue diseases remains unclear, as are the mechanisms for the regulation of these infections in the salivary glands.
Methods: Human herpesvirus (HHV)-7 was isolated and viral DNA was quantified by real-time polymerase chain reaction (PCR) in serially collected saliva samples, to determine whether viral load correlated with infectivity. Then, to examine the role played by beta -herpesviruses in connective tissue diseases, cytomegalovirus, HHV-6, and HHV-7 DNA loads were examined by real-time PCR in serially collected saliva samples from 21 patients with connective tissue diseases.
Results: Although subjects with frequent HHV-7 shedding were more likely to have a high viral load than were other subjects, high viral loads were detected in saliva samples from a portion of the subjects with low viral shedding rates. No significant difference between the quantity of HHV-7 DNA in saliva samples from which active virus was isolated and that amplified from samples without detectable virus was observed. Patients with adult-onset Still disease consistently had high HHV-7 DNA loads, in contrast to patients with other connective tissue diseases (P=.0003) and healthy adults (P=.0224). The mean HHV-6 (P=.012) and HHV-7 (P<.0001) DNA loads in patients with connective tissue diseases were lower than those in healthy adults.
Conclusion: These data suggest that a number of host factors in patients with adult-onset Still disease may function to accelerate HHV-7 replication in the salivary glands.