A young woman on rituximab and two other immunomodulatory agents for the treatment of dermatomyositis developed encephalitis with severe anterograde amnesia. As the use of biologic treatments for refractory autoimmune disease has been increasing, physicians are advised to consider HHV-6 and offer prompt antiviral therapy to limit irreversible morbidity.
Rheumatologists from the UK describe the case of a 32-year old woman who was receiving prednisolone and azathioprine in addition to rituximab for refractory dermatomyositis. She developed headaches, malaise, intermittent fever, mild confusion, and pancytopenia and was admitted to the hospital for treatment. One week after being discharged, she was readmitted upon the development of encephalitis with severe behavioral disturbance, simple partial seizures, profound memory impairment, expressive dysphasia, and fever. HHV-6 DNA was found in the patient’s cerebrospinal fluid (CSF).
After 21 days of valganciclovir and acyclovir, the patient improved but still had marked memory deficits. A year later, however, she showed only minor short term memory deficits. HHV-6 encephalitis is a serious complication in cord and stem cell transplantation, as survivors often suffer permanent disability. In one Japanese study, 80% of patients surviving HHV-6 encephalitis were left with neuropsychological disorders such as anterograde amnesia, seizures, and hippocampal injury, and were unable to return to their prior occupations (Sakai 2011).
To read the full paper, see Baumer 2017.