LGI1 antibody encephalitis: acute treatment comparisons and outcome

Abstract

ObjectiveTo compare acute treatment responses and long-term outcome in leucine-rich glioma-inactivated 1 (LGI1) antibody encephalitis.MethodsRetrospective case series of 118 patients with LGI1 antibody encephalitis evaluated at Mayo Clinic across all US sites from 1 May 2008 to 31 March 2019. Patient clinical data were identified and analysed through the neuroimmunology laboratory and electronic medical record. LGI1 antibody detection was by cell-based indirect immunofluorescence assay of serum, cerebrospinal fluid or both. Clinical outcomes were faciobrachial dystonic seizure (FBDS) resolution, modified Rankin Scale (mRS) score, Kokmen Short Test of Mental Status (STMS) score (0–38 point scale) and neuropsychometric testing results.ResultsCompared with intravenous immunoglobulin (IVIg) (n=21), patients treated with single-agent acute corticosteroids (intravenous, oral or both) (n=49) were more likely to experience resolution of FBDS (61% vs 7%, p=0.002) and improvements in mRS score (ΔmRS score 2 vs 0, p=0.008) and median Kokmen STMS scores (ΔKokmen STMS score 5 points vs 0 points, p=0.01). In 54 patients with long-term follow-up (≥2 years), the median mRS score was 1 (range 0–6) and the median Kokmen STMS score was 36 (range 24–38) after all combinations of immunotherapy. Neuropsychometric testing in 32 patients with long-term follow-up (≥2 years) demonstrated short-term memory impairments in 37%.ConclusionsCorticosteroids appeared more effective acutely than IVIg in improving LGI1 antibody encephalitis in this retrospective comparison of immunotherapies. While improvement with immunotherapy is typical and long-term outcome is favourable, short-term memory deficits are noted in approximately a third of the patients.

IgG4 Autoantibodies in Organ-Specific Autoimmunopathies: Reviewing Class Switching, Antibody-Producing Cells, and Specific Immunotherapies

“…in a recent study with LGI1 encephalitis patients. In this large retrospective case series of 118 patients with LGI1 encephalitis patients, the authors observed that IVIGs were less efficient in comparison with corticosteroid treatment ( 184 ). Nevertheless, IVIGs did have an effect and fared better than placebo in a small randomized placebo-controlled trial, in which patients with anti-LGI1 antibody-associated epilepsy (all with predominantly IgG4 autoantibodies) showed response in 6 out of 8 patients in the IVIG group, compared to zero response in the 6 patients in the placebo group ( 185 ).…”

The safety and efficacy of intravenous immunoglobulin in autoimmune encephalitis

“…In addition, the upfront use of steroid before the trial enrollment in some of the patients might have accelerated the recovery during the trial. Steroid might be more effective than IVIG in the acute treatment of LGI1 encephalitis, 25 and is still one of the cost‐effective treatments. Accordingly, future studies can investigate the optimal first‐line treatment protocols by comparing some of them, or enroll patients with steroid‐non responsiveness.…”

Thymoma-associated anti-LGI1 encephalitis and myasthenia gravis: A unique combination with autoantibodies

“…Accordingly, we performed the second mPSL pulse therapy to stabilize her general condition just before thymomectomy, followed by tapering down of oral prednisolone slowly. A recent retrospective study indicated that corticosteroids are more effective than intravenous immunoglobulin (IVIG) for treatment of LGI1 encephalitis in the acute phase [ 11 ]. Therefore, LGI1 encephalitis without a thymoma can be treated with corticosteroids.…”