Human Herpesvirus 6 Chromosomal Integration in Immunocompetent Patients Results in High Levels of Viral DNA in Blood, Sera, and Hair Follicles

Six immunocompetent patients with human herpesvirus 6 (HHV-6) chromosomal integration had HHV-6 and {szligbeta}-globin DNA quantified in various samples by PCR. The mean HHV-6 DNA concentration (log₁₀ copies/milliliter) in blood was 7.0 ([>/=]1 HHV-6 DNA copies/leukocyte), and in serum it was 5.3 ([>/=]1 HHV-6 DNA copies/lysed cell). The mean HHV-6 DNA load (log₁₀ copies)/hair follicle was 4.2 ([>/=]1 copies/hair follicle cell), demonstrating that viral integration is not confined to blood cells. The characteristically high HHV-6 DNA levels in chromosomal integration may confound laboratory diagnosis of HHV-6 infection and should be given due consideration.