Clinical Features And Characteristics Of CSF Cytology In Different Types Of Autoimmune Encephalitis

Objective:In this paper,45 cases of autoimmune encephalitis(AE)were collected,and their general clinical data,including manifestation,laboratory examination,EEG and brain MRI,cerebrospinal fluid(CSF)examination,tumor screening,treatment and effect,follow-up results were comprehensively analyzed.Besides,with the related literature,we discussed the common types of AE patients and summarized the characteristics to provide powerful reference for AE.Methods:49 cases of AE were Collected from January 2016 to October 2020 in affiliated hospital of Jining Medical University,and the patients’general information,clinical manifestation,tumor screening,laboratory examination(including blood routine examination,homocysteine,blood lipid,D-dimer,etc),CSF routine,biochemical and immune protein and cytological examination,EEG and brain MRI,treatment methods and effect,follow-up results were collected.Then,the data of these 49 patients with AE were retrospectively analyzed,and the specific information of each patient were described by charts,frequency and percentage.Moreover,CSF indexes including intracranial pressure,white blood cell count,protein content and CSF cytology were analyzed.Fisher’s exact test was used to compare the CSF routine examination and CSF cytological examination,and Kappa test was used for their consistency analysis.Relation between CSF cytology and follow-up results were analyzed using Fisher’s exact test,and P<0.05 was considered statistically significant.Results:49 cases diagnosed as AE with positive CSF and/or serum antibody were collected.There is 14 cases of anti-NMDAR encephalitis patients,27 cases of anti-LGI1R,6 patients of anti-GABAβR,2 cases of anti-GADR.Amid them,CSF routine examination alone was performed in 42 patients,28 patients was performed with both CSF routine and cytology examination.1.Clinical features:the average age of the patients was(50.1±17.1)years old,female:male 19:30.Symptoms:NMDA:The most common initial symptoms were mental behavior abnormalities,but also epileptic seizures,consciousness disorders,cognitive,memory and language disorders.5patients(37%)had a history of fever and headache prodrome,and some of them were complicated with autonomic nervous dysfunction and central hypopnea.LGI1:the proportion of it was the highest In our study,the most common initial symptoms was epileptic seizure,also can be conscious disorders,cognition,memory,language disorders,involuntary movement,etc.,10 patients(37%)complicated with intractable hyponatremia and hyponachloremia.GABA:All the 6 patients were admitted with epileptic status as the first symptom,and may have cognitive decline later.GAD:1 initial symptom is mental behavior disorder,1 initial symptom is memory impairment.8 patients(16%)developed lower extremity thrombus/pulmonary embolism.40 patients(83%)had abnormal brain MRI signals,mostly in the frontal/subcortical lobe,temporal lobe,basal ganglia region,hippocampus and other parts.EEG of 25 patients showed mild to moderate abnormality,only 1 patient showed severe abnormality,and no characteristic EEG waveform was found.2.Peripheric blood examination:peripheral blood leukocytes increased in 16 patients,neutrophils increased in 20 patients,albumin decreased in18 patients,and homocysteine slightly increased in 19 patients.Thyroid function,rheumatism,superoxide dismutase,blood lipid,anti-thyroid peroxidase antibody(ATPOAB),anti-thyroglobulin antibody(ATGA)and anti-nuclear antibody(ANA)were basically normal.3.CSF:Routine examination of CSF in 42 patients showed that 14 cases of anti-NMDAR encephalitis patients,22 cases of anti-LGI1R,6 patients of anti-GABAβR.The mean intracranial pressure was(147.21±50.30)mm H2O,the mean protein concentration was(0.67±0.94)g/L,sugar and chloride were basically normal,and there were 15 patients(35.7%)with positive white blood cell count.CSF cytology was performed in 28patients:11 patients were positive for anti-NMDAR,13 were positive for LGI1R,and 4 were positive for anti-GABA_βR.11 patients(39.3%)showed inflammatory reaction,and the degree of inflammatory reaction was mild,moderate and severe in 6,3 and 2 cases,respectively.Among the anti-NMDAR patients,3 were mild,1 was moderate and 2 were severe.Among the anti-NMDAR patients as well as anti-GABA_βR patients,1 was mild,1 was moderate.In terms of the type of inflammatory reaction,11 cases were lymphatic-monocyte inflammatory reaction,no eosinophils or neutrophils were observed.Activated lymphocytes were detected in 4(14.3%)anti-NMDAR patients and plasma cells were detected in 4(14.3%)anti-NMDAR patients.A comparative analysis of 28 patients who underwent both routine CSF and cytological examination showed that the cytological positive rate of CSF(11/28)was higher than that of routine CSF examination(8/28)(P=0.03).4.Treatment and prognosis:Most patients with anti-NMDAR and LGIR encephalitis have a good prognosis.Amid them,Most patients can improve their symptoms after hormone and immunoglobulin treatment.Antiepileptic drugs can help to improve the symptoms of epilepsy and convulsions.Patients with anti-GABA_βR and anti-GADR had poor prognosis.2 patients with anti-GABAβR encephalitis died of lung cancer,2 patients were found to have lung occupying after discharge,and 1patient with anti-GADR showed no improvement after hormone therapy,and has now passed away.Conclusion:1.The clinical characteristics are different in different types of AE patients.Clinical manifestations:NMDA:the most common initial manifestations are mental behavior abnormalities,epileptic seizures,consciousness disorders,cognitive,memory and language disorders,half of them have a history of fever and headache,some of them are complicated with autonomic nervous dysfunction,central hypopnea,etc.LGI1:In our study,LGI1 accounted for the highest proportion,and the most common first manifestation was epileptic seizure,also including conscious impairment,cognition,memory,language impairment,involuntary movement,etc.,and half of the patients were complicated with intractable hyponatremia and hyponachloremia.GABA:All patients start with epileptic status and may have cognitive decline in the later stage.GAD:Abnormal mental behavior and memory problems.Blood,imaging and electroencephalogram are not specific,but other diseases such as rheumatism,tumor and infectious diseases can be excluded with them.Most of the patients with hormone shock combined with immunoglobulin can have a better effect,some of the patients with recurrence of immunosuppressant can reduce the recurrence.Patients with anti-LGI1R and anti-NMDAR had better prognosis,patients with anti-GABAR and anti-GADR had poor prognosis.2.CSF examination characteristics are different in different types of AE patients.CSF leukocyte positive rate and degree of inflammation are higher in patients with anti-NMDAR,and CSF leukocyte can be normal or slightly increased in patients with anti-LGI1R,anti-GABAR and anti-GADR.In addition,CSF cytology has a higher positive rate than CSF routine examination,and CSF cytology can be a candidate method when CSF routine examination fails to detect inflammatory response.CSF cytology can be recommended as a routine CSF examination in patients with AE.