OBJECTIVE: Myasthenia gravis (MG) is an autoimmune disease characterized by disrupted neuromuscular synaptic transmission. Efgartigimod, a human Fc receptor antagonist, has been approved for patients with MG. Its potential use for other IgG-mediated neurological autoimmune diseases is unclear. This study aimed to retrospectively evaluate the efficacy and safety of efgartigimod in patients with neurological autoimmune diseases. METHODS: This retrospective study investigated patients with neurological autoimmune diseases who were treated with efgartigimod in the Henan Provincial People's Hospital. The efficacy of the medication was analyzed using the quality-of-life improvement score and the IgG level pre- and post-efgartigimod treatment. The safety of the medication was assessed by considering adverse events and blood parameters. The blood parameters, including routine blood parameters, coagulation, liver, kidney, and immune function. RESULTS: Seventeen patients received efgartigimod in the Henan Provincial People's Hospital from September 1, 2023, to January 31, 2024. In MG patients, myasthenia gravis activities of daily living (MG-ADL) reduced after efgartigimod treatment for 4 weeks compared with baseline (P <
0.05). Autoimmune encephalitis (AE) is a group of inflammatory disease with antibodies against neuronal synaptic and cell surface antigens. Similarly, patients with AE had a statistically significant reduction in modified Rankin scale (mRS) after efgartigimod treatment for 4 weeks compared with baseline (P <
0.05). Guillain Barre syndrome (GBS) is an immune-mediated disease of the peripheral nerves and nerve roots. However, the inflammatory neuropathy cause and treatment (INCAT) scale score didn't statistically differ in GBS patients before and after efgartigimod treatment (P >
0.05). The IgG levels significantly reduced after the first infusion and gradually decreased after multiple infusions (P <
0.05). Most subjects did not have increased IgG serum levels before treatment. IgA, IgM, and complement levels didn't differ significantly with efgartigimod treatment (P >
0.05). There were no changes in blood parameters during the treatment (P >
0.05). CONCLUSIONS: Efgartigimod was effective and safe in neurological IgG-mediated autoimmune diseases, even in patients without increased IgG serum levels.