[A case report of subacute panencephalitis associated with specific T cells sensitized to proteolipid protein (PLP) synthetic peptides identified with rubella virus].

A 37-year-old woman was admitted to the hospital on October 4, 1991 because of fever, headache, and abnormal behavior. Although she was treated with aciclovir, she developed encephalitis, which slowly manifested itself over the next month as meningeal irritation, loss of consciousness, partial seizure, and quadriparesis. Her cerebrospinal fluid showed mild lymphocytic pleocytosis without protein elevation. Serum IgG antibody titer to rubella virus was elevated, but the rubella virus could not be detected in the cerebrospinal fluid by PCR amplification. Her consciousness level improved slowly, and by the end of November she suffered only dystonic posture of her right arm and hand. By the middle of December, there were no abnormal neurological findings except some extrapyramidal tract signs and symptoms, such as tremor and rigidity. The serum rubella virus IgG titer had fallen back into the normal range. Her illness was diagnosed as subacute panencephalitis, and she recovered completely about 5 months after the onset of the disease. The lack of rubella virus in the cerebrospinal fluid suggests that panencephalitis may not be dependent on virus replication within the central nervous system. Specific T cells sensitized to proteolipid protein synthetic peptides (PLP158-166) identified with rubella virus were detected in this case during the active stage. These observations imply that subacute panencephalitis may be dependent on an immune-mediated mechanism and that PLP-specific T cells may play an important role in pathogenesis of the disease.