Elevated LGI1-IgG CSF index predicts worse neurological outcome

Avi Gadoth; Anastasia Zekeridou; Christopher J Klein; Colton J Thoreson; Masoud Majed; Divyanshu Dubey; Eoin P Flanagan; Andrew McKeon; Sarah M Jenkins; Vanda A Lennon; Sean J Pittock

doi:10.1002/acn3.561

Elevated LGI1-IgG CSF index predicts worse neurological outcome

Ann Clin Transl Neurol. 2018 Apr 2;5(5):646-650. doi: 10.1002/acn3.561. eCollection 2018 May.

Authors

Avi Gadoth^{1

2}, Anastasia Zekeridou^{1

2}, Christopher J Klein^{1

2}, Colton J Thoreson², Masoud Majed², Divyanshu Dubey^{1

2}, Eoin P Flanagan^{1

2}, Andrew McKeon^{1

2}, Sarah M Jenkins³, Vanda A Lennon^{1

2

4}, Sean J Pittock^{1

2}

Affiliations

¹ Department of Neurology Mayo Clinic Rochester Minnesota.
² Laboratory Medicine and Pathology Mayo Clinic Rochester Minnesota.
³ Department of Health Sciences Research Mayo Clinic Rochester Minnesota.
⁴ Department of Immunology Mayo Clinic Rochester Minnesota.

Abstract

To determine whether CSF leucine-rich glioma-inactivated 1(LGI1)-IgG titer, index or IgG subclass has prognostic significance, we tested serum and CSF specimens collected concomitantly from 39 seropositive patients. LGI1-IgG index was elevated (>1) in 21 patients (54%), suggesting intrathecal synthesis. Patients with worse outcome at last follow-up (modified Rankin Scale >2) had significantly higher index (median 6.57 vs. 0.5, P = 0.048) compared to those with better outcome. Higher CSF LGI1-IgG4 subclass-specific titer and index correlated with worse outcome (P < 0.005 for both). These data suggest that evidence of intrathecal LGI1-IgG synthesis may correlate with neuronal injury and warrant consideration of aggressive immunotherapy.