Apolipoprotein 4 may increase viral load and seizure frequency in mesial temporal lobe epilepsy patients with positive human herpes virus 6B

• DOI: 10.1016/j.neulet.2014.12.063
• Publication Date: 2015-01-07T12:04:34Z
• Authors: Cheng Huang; Bo Yan; Ding Lei; Yang Si; He Li; Ming-Wan Chen; Li Li; Fei Chen; Qiao Zhou; Dong Zhou; Jin-Mei Li
• Keywords: Adult; Male; Polymorphism, Genetic; Adolescent; Herpesvirus 6, Human; Apolipoprotein E4; Brain; Roseolovirus Infections; Middle Aged; Viral Load; 3. Good health; Viral Proteins; Young Adult; 03 medical and health sciences; 0302 clinical medicine; Epilepsy, Temporal Lobe; Case-Control Studies; DNA, Viral; Humans; Female

This study investigated whether apolipoprotein 4 (ApoE4) was associated with the presence of human herpes virus (HHV)-6B in mesial temporal lobe epilepsy (MTLE). Polymerase chain reaction-restricted fragment length polymorphism (PCR-RFLP) was used to determine ApoE polymorphism in 46 patients with MTLE and 19 controls. Nested PCR and real-time PCR were applied to determine HHV-6B DNA and immunohistochemistry (IHC) for HHV-6B protein. Viral DNA load was significantly increased in MTLE patients with HHV-6B(+)/ApoE4 compared with those with HHV-6B(+)/non-ApoE4 (p=0.031). Semi-quantitative analysis of IHC showed significantly increased number of positive cells for HHV-6B proteins G116/64/54, P98 and U94 in patients with HHV-6B(+)/ApoE4 than HHV-6B(+)/non-ApoE4 (p=0.009, 0.035 and 0.009, respectively). Patients with HHV-6B(+)/ApoE4 showed higher seizure frequency than those with HHV-6B(+)/non-ApoE4 (p=0.005). There was no significant difference of ApoE alleles between MTLE with and without HHV-6B (p=0.115). ApoE4 was not associated with initial infection of HHV-6B in MTLE. However, ApoE4 may facilitate HHV-6B reactivation, DNA replication, virus protein expression and increase seizure frequency in MTLE. Further investigations are needed to understand the biomolecular mechanism underlying interaction between ApoE and HHV-6B.