The purpose of this study was to evaluate the efficacy and safety of low-dose IL-2 in the treatment of immunorelated ALS syndrome.

This is a single-center, open-label, self-controlled clinical study with a sample size of 10 patients for 48 weeks, including 24 weeks of administration, and 24 weeks of follow-up. During the administration period, medication was given for 2 weeks and rest for 2 weeks, as a course of treatment, with a total of 6 courses for 24 weeks. During the administration period, the drug was given on alternate days, and IL-2 1mIU was subcutaneously injected the next day for 7 times, and then rested for 2 weeks, and the cycle was repeated for 6 times. The primary outcome index was the change in the rate of ALSFRS-R score between administration period and follow-up period. Secondary outcome measures included changes in the rate of ALSAQ-40 score, ROADS score, MRC score, survival time, FVC%, Treg and CD4+ T cell subsets, inflammatory factors, serum and cerebrospinal fluid NFL during follow-up versus administration , changes in the inhibition function of Treg; Exploratory outcome indicators included the change degree of compound muscle action potential (CMAP) amplitude, quantitative analysis of corneal nerve morphologic changes by corneal confocal microscopy (CCM), Treg single-cell sequencing transcriptome analysis. The related safety indexes were also evaluated.

Inclusion Criteria:

• 18-70 years old;
• Clinically diagnosed with ALS syndrome, i.e., with ALS -like manifestations, consisting of a combination of upper and/or lower motor neuron damage;
• significant abnormalities with rheumatoid immune-related indicators, or diagnoses of immune-mediated ALS syndrome, including but not limited to multifocal motor neuropathy (MMN), Lewis-Sumner syndrome, and other ALS-like syndromes with an immune background that cannot be clearly classified;
• Poor treatment with conventional hormones or gamma globulin;
• Permitted concomitant treatment: oral prednisone or equivalent doses of other glucocorticoids (≤1.0mg/kg/d); Oral routine dose of immunosuppressants or immunomodulators, such as cyclophosphamide, tacrolimus, etc.; Routine oral doses such as too much force; Doses and types of accompanying therapeutic drugs should not be changed from the trial enrollment to the end of follow-up.
• For women of reproductive age, contraception for at least 2 weeks at the time of enrolment and negative urine HCG;
• Reasonable and effective contraceptive measures should be taken by subjects of childbearing age from the time of trial enrollment to the end of follow-up;
• Signed informed consent.

Exclusion Criteria:

• Allergic or intolerance to IL2;
• Receive non-standard treatment or use of excessive dose of glucocorticoids or gamma globulin intravenously within 2 months before enrollment;
• Vaccination within 6 months before enrolment or between enrolment and the end of follow-up;
• Peripheral venous white blood cells < 2000/mm3, lymphocytes < 600/mm3, platelets < 80,000 /mm3;
• Complicated with severe infection or inflammation, such as bacteremia, sepsis, etc.;
• Complicated blood system diseases, infectious diseases (hepatitis, HIV, tuberculosis, etc.), mental diseases, dementia, severe hypotension, substance abuse history, malignant tumor history, organ transplantation history, etc.;
• Severe liver, kidney, lung or heart dysfunction: heart failure (≥NYHA grade III), renal insufficiency (creatinine clearance ≤30ml/min), abnormal liver function (3 times the upper limit of normal >);
• Pregnant and lactating women;
• Currently participating in other clinical studies or using other investigational drugs.