Human herpesvirus-6 infection in children with cancer.

Pediatric cancer patients treated with multimodal therapy are at a great risk of opportunistic infections or reactivation of latent infections. Human herpesvirus-6 (HHV-6) can serve as an example of such infection, with high seroprevalence in population. In 66 children with cancer and in 45 healthy controls, age matched, the presence of DNA HHV-6 was examined in peripheral blood by the polymerase chain reaction method. HHV-6 serology was also performed. No difference has been found between patients at the time of cancer diagnosis and the group of healthy children in the presence of DNA HHV-6 in blood, 17.4 and 15.6%, respectively. During cytotoxic chemotherapy the presence of HHV-6 in peripheral blood raised to 37.1% in patients with fever. Other parameters and symptoms such as febrile neutropenia, lymphopenia, exanthem, hepatopathy, lymphadenopathy, enteritis, bone marrow aplasia, pneumonitis, and encephalitis were examined in both the HHV-6 positive and HHV-6 negative groups of pediatric cancer patients. Statistically significant differences (p < .05) were found in case of lymphopenia, exanthem, and hepatopathy. In 4 out of 66 patients (6.1%) severe HHV-6 infection has been found: in 3 patients during cytotoxic chemotherapy and in 1 at the time of cancer diagnosis. Reactivation of HHV-6 infection in pediatric cancer patients under treatment with cytotoxic chemotherapy is frequent and can lead to severe complications as described in patients after bone marrow or organ transplantation.