Guillain-barre syndrome (GBS) is an acute immune-mediated polyneuropathy. Intravenous Gamma globulin is an effective therapy.Although high doses of gamma globulin are clinically effective, the patient's recovery and clinical prognosis vary. The establishment of a cohort study on the therapeutic effect of gamma globulin in Guillain-barre Syndrome is beneficial to the diagnosis of the disease and to the understanding of the natural course of the disease and the efficacy of drug treatment.

Inclusion Criteria:

1. Meet the Brighton Guillain-Barre Syndrome diagnosis criteria in 2014;
2. Age ≥18;
3. Patients with AIDP, AMAN and AMSAN;

5. IVIG was treated within 2 weeks of onset; 6. GBS disability scale>2; 6. Cooperate with patients who were followed up for 180 days and sign the informed consent;

Exclusion criteria:

1. Age <18;
2. Pregnant or nursing women;
3. Patients with Chronic inflammatory demyelinating multiple peripheral neuropathy;
4. Combined with other types of immune system diseases;
5. Accept drugs that affect the function of the immune system within 5 or 3 months;
6. Concomitant neoplastic diseases.
7. The patient or guardian refused to sign the informed consent.

Patients with GBS after standard IVIg treatment in relation to slow clinical course or worse outcome