The purpose of the present invention is to provide a detection system capable of diagnosing, treating, and preventing complications after transplant, especially, complications with neurological symptoms. More specifically, the present invention relates to a diagnosing method of limbic encephalitis, paraneoplastic syndrome (PNS), encephalomyelitis, leukoencephalopathy, retinitis or optic atrophy, which comprises a step of detecting Borna viruses from a sample, preferably mammal 2 Borna viruses, more preferably VSBV-1 and mammal 1 Borna viruses, and much more preferably Borna viruses from a group containing BoDV-1. In addition, the present invention relates to a carrier containing a capturing means of an antibody for at least one polypeptide selected from a group containing BoDV-1-N, BoDV-1-P, VSBV-N and VSBV-P; a kit containing the carrier or means for detecting capture antibodies and a control group for detecting an existence of samples; and a carrier or a kit for monitoring prognosis of diagnosis of encephalitis and complications after transplant or treating method of encephalitis or complications after transplant, or for distinguishing autoimmune encephalitis from encephalitis caused by infection; or a primer suitable for detecting Borna viruses or a usage of a probe.
METHOD FOR DIAGNOSING A BORNAVIRUS INFECTION