Human herpesvirus 6 in cerebrospinal fluid of patients infected with HIV: frequency and clinical significance

The objective was to evaluate the frequency of human herpesvirus 6 (HHV-6) DNA detection in the CSF of patients infected with HIV and its relation to brain disease and systemic HHV-6 infection. Nested polymerase chain reaction (PCR) was used to analyse CSF samples from 365 consecutive HIV infected patients with neurological symptoms. When ava ilable, plasma and brain tissues from patients whose CSF was HHV-6 positive were also studied. HHV-6 was found in the CSF of eight of the 365 patients (2.2%): two had typ e A and four type B; the HHV-6 variant could not be defined in the remainin g two. All eight patients had neurological symptoms and signs related to co ncomitant opportunistic brain diseases, including cytomegalovirus (CMV) enc ephalitis in five patients whose CSF was also positive for CMV-DNA. Opportu nistic infections but no other unexplained lesions were also found in the b rain of all of the four patients who underwent neuropathological examinatio n. Both HHV-6 and CMV were also detected in the plasma of respectively five and seven of seven patients whose CSF was HHV-6 positive. In conclusion, HHV-6 type A or B DNA was infrequently found in the CSF of H IV infected patients, in association with both CMV brain infection and syst emic HHV-6 replication. However, no certain relation between HHV-6 and brai n disease was found.