Objective:To analyse the clinical features of encephalitis patients with antibodies against the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR).Methods:Three anti-AMPAR encephalitis patients diagnosed in Tangdu Hospital, the Air Force Military Medical University between January 2020 and May 2021 were retrospectively reviewed. The clinical symptoms, supplementary examination, treatment options and outcomes with knowledge from literature were summarized in this study.Results:Three patients aging from 12 to 70 years presented with symptoms ranging from cognitive impairment, personality change to headache and paralysis. The lung occupying lesion was pathologically proved to be small cell lung cancer in case 1. Antibody to AMPAR (AMPAR-ab) was positive in both blood and cerebrospinal fluid of case 1, with coexisting antibodies against sex-determining region of Y chromosome-related high mobility group box 1 in blood, and the symptoms persisted but did not recur following therapy with corticosteroids. AMPAR-ab was detected only in serum in case 2, with the lesion located in both frontal and temporal lobes, centrum semiovale and lateral ventricle, combined with classic imaging features of intracranial hypotension, and the syndrome was partially improved following treatment with corticosteroids. The lesions were located in the pons and middle cerebellar peduncle, accompanied by cerebellar atrophy in case 3. Spinal cord magnetic resonance imaging showed long hyperintense lesions involving the cervical and thoracic cord, extending from C 2 to Th 10 level on T 2-weighted images. AMPAR-ab was positive in both serum and cerebrospinal fluid. And the symptoms improved significantly following treatment with corticosteroids and intravenous immunoglobulin. Conclusions:The clinical manifestations of anti-AMPAR encephalitis are highly heterogeneous, and brainstem and spinal cord can also be involved in addition to the limbic system, accompanied by brain atrophy. Combining with concurrent antibodies, especially the intracellular antibodies, malignancy needs to be closely monitored; the immunotherapy is effective and the presence of tumor superimposed with multiple antibodies may be associated with poor prognosis.

BCG vaccine is one of the most widely used vaccines in human history, with tens of billions of doses administered annually over the past century as an important means of preventing tuberculosis. However, BCG is also used for non-traditional purposes of prevention and treatment, such as bladder cancer immunotherapy. In addition to cancer immunotherapy, BCG is increasingly found to be helpful for a variety of immune diseases, including multiple sclerosis, typeⅠdiabetes, and some atopic diseases. It also can protect against non-tuberculous mycobacterium infections, viral infections and even COVID-19. This allogenic protective effect lies in the BCG vaccine's ability to alter immune set points through allogenic T cell immunity, as well as in the epigenetic and immunological effects of metabolomic changes in innate immune cells, a process known as ^“training immunity^”. This paper summarizes the anti-TB effect of BCG and focuses on its heterologous protection and related mechanism.