The purpose of this paper is to analysis of therapeutic effect and immunological mechanism of low-dose IL-2 combined with rapamycin in the treatment of Sjogren's syndrome

A randomized, open clinical trial was designed. Patients will be randomly divided into three groups，including Ld-IL2 group, rapamycin group, Ld-IL2+rapamycin group. The improvement of clinical and laboratory indexes will be evaluated. Changes of immune cell subsets and cytokines will be monitored.

Inclusion Criteria:

1. Male or female, and aged 18-70 at the time of screening visit.
2. Patients with Sjogren's syndrome who meet the 2002 EULAR classification criteria.
3. If the standardized treatment is not effective or relapses, it is clinically necessary to give additional immunomodulatory treatment.
4. Disease activity: ESSDAI≥4 points.
5. The pregnancy test results of female subjects of childbearing age should be negative at screening and baseline.
6. The written informed consent form approved by the Ethics Committee of Peking University People's Hospital was signed and dated by the subject or legal representative.

Exclusion Criteria:

1. Severe chronic liver, kidney and heart dysfunction.
2. Severe drug-resistant bacterial infections, such as bacteremia and septicemia.
3. Patients with tumor and tumor history.
4. Chronic respiratory failure.
5. Patients who are ineffective in high-dose hormone pulse therapy.
6. Those who use rituximab or other biological agents within 3 months.
7. Patients with active tuberculosis infection or potential tuberculosis infection.
8. There are obstacles that can't cooperate or cause interference in completing this research: such as mental patients.