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Updated: Nov 9, 2025
Immunoglobulin Gene Sequence Analysis In Chronic Lymphocytic Leukemia: From Patient Material To Sequence Interpretation
Published on: November 26, 2018
Clinical and Prognostic Value of Immunogenetic Characteristics in Anti-LGI1 Encephalitis
Sergio Muñiz-Castrillo1, Julie Haesebaert1, Laure Thomas1
1From the French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis (S.M.-C., L.T., A.V., A.-L.P., G.P., C.B., L.-D.D., B.J., V.R., J. Honnorat), Hospices Civils de Lyon, Hôpital Neurologique, Bron, France; SynatAc Team (S.M.-C., L.T., A.V., A.-L.P., G.P., C.B., L.-D.D., B.J., V.R., J. Honnorat), Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, France; Clinic Research and Epidemiology Department (J. Haesebaert), Hospices Civils de Lyon, Lyon, France, HESPER Team, EA 7425, Medicine School, Université Claude Bernard Lyon 1, France; Neurology Department 2-Mazarin (G.B., D.P., A. Alentorn), Hôpitaux Universitaires La Pitié Salpêtrière-Charles Foix, APHP; Brain and Spinal Cord Institute (G.B., D.P., A. Alentorn), INSERM U1127/CNRS UMR 7255, Université Pierre-et-Marie-Curie, Universités Sorbonnes, Paris, France; HLA Laboratory (V.D.), French Blood Service, EFS Auvergne-Rhône-Alpes, Lyon, France; Stanford University Center for Sleep Sciences and Medicine (A. Ambati, E.M.), Palo Alto, CA; and Department of Psychiatry (R.T.), Hôpitaux Universitaires Henri Mondor, Créteil, France, Mondor Institute for Biomedical Research, INSERM U955, Université de Paris-Est-Créteil, France.
Objective:
Antibodies against leucine-rich glioma-inactivated 1 (LGI1-Abs) characterize a limbic encephalitis (LE) strongly associated with HLA-DRB1*07:01, although some patients lack LGI1-Abs in CSF or do not carry this allele. Whether they represent a different subtype of disease or have different prognoses is unclear.
Methods:
Retrospective analysis of clinical features, IgG isotypes, and outcome according to LGI1-Ab CSF positivity and DRB1*07:01 in a cohort of anti-LGI1 LE patients.
Results:
Patients with LGI1-Abs detected in both CSF and serum (105/134, 78%) were compared with those who were CSF negative (29/134, 22%). Both groups had similar clinical features and serum levels, but CSF-positive patients had shorter diagnostic delay, more frequently hyponatremia, inflammatory CSF, and abnormal MRI (p < 0.05). Human leukocyte antigen (HLA) genotyping was performed in 72/134 (54%) patients and 63/72 (88%) carried DRB1*07:01. Noncarriers (9/72, 12%) were younger, more commonly women, and had less frequently psychiatric and frontal symptoms (p < 0.05). No difference in IgG isotypes according to CSF positivity or HLA was found (p > 0.05). HLA and IgG isotypes were not associated with poor outcome (mRS >2 at last follow-up) in univariate analyses; CSF positivity was only identified as a poor outcome predictor in the multivariate analysis including the complete follow-up, whereas age and female sex also remained when just the first year was considered.
Conclusions:
LE without CSF LGI1-Abs is clinically indistinguishable and likely reflects just a lesser LGI1-Ab production. HLA association is sex and age biased and presents clinical particularities, suggesting subtle differences in the immune response. Long-term outcome depends mostly on demographic characteristics and the intensity of the intrathecal synthesis.
