Caregiver burden and fatigue in caregivers of people with dementia: Measuring human herpesvirus (HHV)-6 and -7 DNA levels in saliva.

PURPOSE: We examined chronic fatigue, which has not been investigated in detail, in family caregivers for people with dementia. METHODS AND MATERIALS: Forty-four community-dwelling family caregivers (the caregiver group: CG) and 50 elderly control participants (the non-caregiver group: NCG) participated in this study. We measured salivary human herpesvirus (HHV)-6 and -7 DNA levels and the Chalder fatigue scale (CFS) to assess levels of fatigue; we also measured the Center for Epidemiologic Studies-Depression Scale, Physical Activity Scale for the Elderly, Zarit Caregiver Burden Interview, Mini-Mental State Examination, Assessment of Motor and Process Skills, and Dementia Behavior Disturbance Scale. RESULTS: For CG, the salivary HHV-6 DNA levels and CFS scores were significantly higher than those in NCG. The salivary HHV-6 DNA levels in CG were significantly correlated with depressive symptoms, the cognitive function of the patients, and the activities of daily living/instrumental activities of daily living (ADL/IADL) abilities of the patients. The CFS scores in CG significantly correlated with caregiver burden, depression symptoms, leisure physical activity, the number of other family caregivers, and the hours spent for caregiving per week, as well as with behavior disturbances and ADL/IADL abilities. CONCLUSIONS: The salivary HHV-6 DNA levels may be added as a new biomarker for caregiver exhaustion. We concluded that fatigue assessments should be performed by not only a questionnaire, such as the CFS, but also by a biomarker search, such as HHV-6, when estimating the caregiver burden for family caregivers of people with dementia.

Type specific Real time PCR for detection of human herpes virus 6 in schizophrenia and bipolar patients: a case control study.

BACKGROUND: Schizophrenia (SC) and bipolar disorder (BD) are among the most devastating diseases worldwide. There are several lines of evidence suggesting that viruses may play significant roles in the etiology of these mental disorders. The aim of this study was the detection of HHV-6A/B in the peripheral blood mononuclear cells (PBMC) of SC and BD patients versus the healthy control (HC) subjects using a new method of type-specific Real time PCR analysis. METHODS: A type-specific Real time PCR was performed for simultaneous detection and typing of HHV-6A/B in the PBMCs of 120 SC and BD patients and 75 HCs. RESULTS: Only one case of HHV-6B out of 120 (0.8 %) SC and BD patients and two cases of HHV-6A (2.7 %) in 75 HCs were detected. CONCLUSIONS: The low levels of HHV-6 detection in PBMCs, severely limited the capacity of this study to investigate the association between the presence of HHV-6 and BD or SC in this population, thus no conclusions can be drawn in this regard. Meanwhile this study introduces a Real time PCR based method for type specific detection of HHV-6A/B in clinical samples.

Antiviral therapy of two patients with chromosomally-integrated human herpesvirus-6A presenting with cognitive dysfunction.

BACKGROUND: Human herpesvirus 6 (HHV-6) is a neurotropic virus implicated in central nervous system (CNS) dysfunction, multiple sclerosis, seizures and encephalitis. Inherited or "chromosomally integrated" HHV-6 (CIHHV-6) is a condition characterized by high DNA loads and germ line transmission of HHV-6 genomes, which are integrated into the telomere. OBJECTIVES: We previously reported that integrated HHV-6 can be reactivated by trichostatin A in vitro. Therefore, we hypothesized that a broad array of neurological symptoms of CIHHV-6 patients may respond to antiviral drug treatment. STUDY DESIGN: The patients have been treated with antiviral drugs and monitored for viral load, late mRNA, and clinical improvement. RESULTS: Antiviral therapy of two CIHHV patients resulted in successful clinical resolution. However, both patients relapsed on multiple occasions within 4-6 months of cessation of antiviral therapy. CONCLUSIONS: Successful antiviral drug treatment suggests that clinical symptoms of these patients were due to symptomatic reactivation of CIHHV-6. Alternatively, some CIHHV-6 patients may have a reduced resistance to community-acquired HHV-6 strains due to tolerance leading to persistent infections.