From the Neuroncology Unit (G.B., E.V., E.M.), and Neuroradiology Unit (M.P., A.P.), IRCCS Mondino Foundation, Pavia; Molecular Virology Unit (G.C., F.B.), Microbiology and Virology Department, Diagnostic Radiology, Interventional Radiology and Neuroradiology Unit (A.M.S.), Bone Marrow Transplantation Unit (A.A.C., P.B., O.B.), Infectious and Tropical Diseases Unit (A.D.M.), Pediatric Clinic (V.R., T.F., S.S.), and Pediatric Hematology/Oncology (F.C., M.Z.), Fondazione IRCCS Policlinico San Matteo, Pavia; and Department of Brain and Behavioral Sciences (A.P.), Department of Molecular Medicine (P.B., O.B.), and Department of Clinical, Surgical, Diagnostic and Paediatric Sciences (F.B.), University of Pavia, Italy.
Neurol Neuroimmunol Neuroinflamm. 2021 Jan 12;8(2). doi: 10.1212/NXI.0000000000000942. Print 2021 Mar.
The aim of this study was to analyze the clinical, radiologic, and biological features associated with human herpesvirus 6 (HHV-6) encephalitis in immunocompetent and immunocompromised hosts to establish which clinical settings should prompt HHV-6 testing.
We performed a retrospective research in the virology database of Fondazione IRCCS Policlinico San Matteo (Pavia, Italy) for all patients who tested positive for HHV-6 DNA in the CSF and/or in blood from January 2008 to September 2018 and separately assessed the number of patients meeting the criteria for HHV-6 encephalitis in the group of immunocompetent and immunocompromised hosts.
Of the 926 patients tested for HHV-6 during the period of interest, 45 met the study criteria. Among immunocompetent hosts (n = 17), HHV-6 encephalitis was diagnosed to 4 infants or children presenting with seizures or mild encephalopathy during primary HHV-6 infection (CSF/blood replication ratio <<1 in all cases). Among immunocompromised hosts (n = 28), HHV-6 encephalitis was diagnosed to 7 adolescents/adults with hematologic conditions presenting with altered mental status (7/7), seizures (3/7), vigilance impairment (3/7), behavioral changes (2/7), hyponatremia (2/7), and anterograde amnesia (1/7). Initial brain MRI was altered only in 2 patients, but 6 of the 7 had a CSF/blood replication ratio >1.
The detection of a CSF/blood replication ratio >1 represented a specific feature of immunocompromised patients with HHV-6 encephalitis and could be of special help to establish a diagnosis of HHV-6 encephalitis in hematopoietic stem cell transplant recipients lacking radiologic evidence of limbic involvement.
本研究旨在分析与免疫功能正常和免疫功能低下宿主的人类疱疹病毒 6（HHV-6）脑炎相关的临床、影像学和生物学特征，以确定哪些临床情况应提示进行 HHV-6 检测。
我们对 2008 年 1 月至 2018 年 9 月期间在意大利帕维亚的圣马特奥基金会 IRCCS 综合医院（Fondazione IRCCS Policlinico San Matteo）病毒学数据库中进行 HHV-6 DNA 检测呈阳性的所有患者进行了回顾性研究，并分别评估了免疫功能正常和免疫功能低下宿主中符合 HHV-6 脑炎标准的患者数量。
在所关注的时间段内，共有 926 例患者接受了 HHV-6 检测，其中 45 例符合研究标准。在免疫功能正常的宿主（n=17）中，诊断为 4 例婴儿或儿童在原发性 HHV-6 感染期间出现癫痫发作或轻度脑病（所有病例的 CSF/血液复制比值均<1）。在免疫功能低下的宿主（n=28）中，诊断为 7 例患有血液疾病的青少年/成人，表现为精神状态改变（7/7）、癫痫发作（3/7）、警觉性损害（3/7）、行为改变（2/7）、低钠血症（2/7）和逆行性遗忘（1/7）。初始脑 MRI 仅在 2 例患者中发生改变，但 7 例中有 6 例 CSF/血液复制比值>1。
检测 CSF/血液复制比值>1 是免疫功能低下的 HHV-6 脑炎患者的一个特定特征，对于缺乏边缘叶受累的放射学证据的造血干细胞移植受者，可能有助于建立 HHV-6 脑炎的诊断。
