Relationship between Borna disease virus infection and patients with encephalitis with mental and behavioral disorders

Abstract

Objective To discuss the relationship between Borna disease virus (BDV) infection and the patients of encephalitis with mental and behavioral disorders, as well as to analyze the clinical features of patients infected by BDV. Methods The p24 and p40 gene fragment of BDV in 36 patients with encephalitis, 34 healthy donors and 30 patients with spinal anaesthesia were examined in peripheral blood mononuclear cells(PBMCs)and cerebrospinal fluid mononuclear cells by nested fluorescence quantitative-nest reverse transcription-PCR. In the meantime, β-actin in specimens was detected by PCR as an internal reference. The clinical characteristics of patients with encephalitis with mental and behavioral disorders infected by BDV were summarized. The patients with positive mental symptoms were given a mark with the Positive And Negative Syndrome Scale. Results The positive rate (4/36, 11.1%) of BDVp24 and BDVp40 in PBMCs and cerebrospinal fluid mononuclear cells in mental encephalitis was significantly higher than that in healthy donors and patients with spinal anaesthesia (0/34, 0/30; P=0.015), and the number of copies of BDVp24 and BDVp40 in PBMCs was more than 102 kb/μl. One patient was positive in cerebrospinal fluid of BDVp24 gene fragment but was negative in PBMCs of BDVp40. The homologies of the gene sequence of positive product were genetically related to the virus strain BDV from horse. The clinical features of encephalitis patients with positive products were mainly hallucination and delusion. Conclusions BDV infection is correlated with encephalitis patients with mental and behavioral disorders. The clinical features of patients with BDV infection were mainly positive mental symptoms. Key words: Borna disease virus; Encephalitis, viral; Neurobehavioral manifestations; Viral proteins