Clinical Characterization Of Leucine-rich Glioma Inactivating Protein 1 Antibody Encephalitis And Changes In CHI3L1 In Patients’ Serum And Cerebrospinal Fluid

ObjectiveAnti-leucine-rich,glioma-inactivated 1(LGI1)encephalitis is a rare autoimmune disease of the central nervous system.In this study,we retrospectively analyzed the clinical and ancillary features of patients with LGI1 encephalitis and tested serum and cerebrospinal fluid CHI3L1 levels in patients with anti-LGI1 encephalitis.To investigate the relationship between changes in serum and cerebrospinal fluid chitinase-3-like 1(CHI3L1)levels and each clinical characteristic in patients with anti-LGI1 encephalitis.MethodsSeventy-seven patients with anti-LGI1 encephalitis diagnosed at the Department of Neurology,Qilu Hospital,Shandong University,who were seen between January 2017 and June 2022 were included in this study.A retrospective analysis of the clinical manifestations and clinical auxiliary examinations of patients with anti-LGI1 antibody encephalitis and a 6-month follow-up was conducted.The mRS score was used to reflect the severity of the patient’s disease at admission and after 6 months of follow-up.Patient information is collated,and the clinical characteristics of patients are analyzed.In this study,serum and/or cerebrospinal fluid from 35 patients with acute anti-LGI1 encephalitis diagnosed between January 2017 and January 2022 were selected and matched with serum and cerebrospinal fluid from 22 patients with non-inflammatory neurological disease as controls.The enzyme-linked immunosorbent assay was used to measure CHI3L1 levels in serum and cerebrospinal fluid(CSF)from anti-LGI1 encephalitis patients and controls.ResultsA total of 77 patients with anti-LGI1 encephalitis were included in this study,and the patients were predominantly elderly males.The admission mRS score of patients with anti-LGI1 encephalitis was positively correlated with the presence of hyponatremia in patients;the mRS score was positively correlated with age,time of diagnosis,and cerebrospinal fluid cell count of patients with anti-LGI1 encephalitis after 6 months of follow-up.Patients in the FBDS group had significantly higher mRS scores on admission than those in the non-FBDS group;patients presenting with FBDS only had significantly higher mRS scores on admission and after 6 months of follow-up than other patients presenting with FBDS.The mRS score at 6 months follow-up was significantly higher in patients with an acute or subacute diagnosis than in patients with a chronic diagnosis;the cerebrospinal fluid IgG levels,cerebrospinal fluid IgA levels,and cerebrospinal fluid IgM levels were significantly higher in patients with an acute or subacute diagnosis than in patients with a chronic diagnosis.CHI3L1 levels in blood and cerebrospinal fluid were considerably higher in patients with anti-LGI1 encephalitis than in controls in this study.Patients with anti-LGI1 encephalitis who had cognitive impairment had significantly higher levels of CHI3L1 in their cerebrospinal fluid than patients with anti-LGI1 encephalitis who did not have cognitive impairment,and patients with anti-LGI1 encephalitis who had cognitive impairment had significantly higher mRS scores at admission and at the 6-month follow-up examination than patients with anti-LGI1 encephalitis who did not have cognitive impairment.Cerebrospinal fluid CHI3L1 levels were positively correlated with mRS scores at admission and after 6 months of follow-up in patients with anti-LGI1 encephalitis.Conclusion1.The severity of disease in patients with LGI1 encephalitis is associated with the presence of hyponatremia,while the prognosis of patients is correlated with their age,time of diagnosis,and increased lymphocyte count in the cerebrospinal fluid;2.Patients with anti-LGI1 encephalitis presenting with FBDS had a lower disease severity and a better prognosis than those without FBDS;3.Patients with anti-LGI1 encephalitis had significantly higher levels of CHI3L1 in serum and cerebrospinal fluid,and the level of CHI3L1 in cerebrospinal fluid correlated with the severity of the disease and the prognosis of the patients;CHI3L1 is a potential marker for the assessment of disease and prognosis in patients with anti-LGI1 encephalitis.