Evaluation and prediction of relapse risk after glucocorticoid or immunosuppressant withdrawal in patients with stable IgG4 related disease: a prospective cohort study from china.

IgG4-related disease (IgG4-RD) is a chronic autoimmune disease with a relapsing-remitting course. For patients in remission, glucocorticoid (GC) and immunosuppressant are used to be maintained for a long time in fear of disease flare. Long-term GC and immunosuppressant could bring a lot of side-effects and economic burden. Whether and when patients with stable disease should withdraw GC or immunosuppressant? How about the relapse risk respectively? What are the risk factors for disease flare? All the above remain unclear. The aim of this study is to explore the relapse risk after GC or immunosuppressant withdrawal in IgG4-RD patients with stable disease and to establish a predictive model for risk stratification. Meanwhile the investigators aim to testify the effects of immunosuppressant in preventing IgG4-RD relapse. This study is a prospective cohort clinical trial.

Inclusion Criteria:

1. All patients must meet the following diagnostic criteria of IgG4RD (2011): 1)Swelling, sclerosing and inflammatory involvement of one or more organ, including sclerosing pancreatitis, sialadenitis (Mikulicz disease), sclerosing cholangitis, inflammatory pseudotumors, retroperitoneal or mediastinal fibrosis, interstitial nephritis, hypophysitis, sclerosing dacryoadenitis, inflammatory aortic aneurysm, lymphadenopathy, or other inflammatory conditions; 2)Elevated serum IgG4 (>1.35 g/L); 3)Histopathologic features of fibrosis and/or lymphocytic and polyclonal plasma cell infiltration (and IgG4+ plasma cells on immunohistology when performed). Patients fulfill 1)+2)+3) are diagnosed as definite IgD4RD, 1)+2): possible IgG4RD; 1)+3): probable IgG4RD. exclusion of other diseases.
2. Disease stabilized more than one year (Responder Index < 2 points)
3. Dose of Glucocorticoid(GC): prednisone (or equivalent) ≤ 7.5mg/d for more than 6 months
4. Immunosuppressant: one of the following drugs, the same dose maintain at least 3 months (Mycophenolate mate <= 1g/d or Leflunomide <=20mg/d or Methotrexate <=12.5mg/w or Azathioprine <=100mg/d).

Exclusion Criteria:

1. Patient was diagnosed other connective tissue diseases
2. Patient with tumor
3. Women during pregnancy or planning pregnancy
4. Patient with active infections, including HIV, HCV, HBV, TB, etc.
5. Patient with severe irreversible organ damage
6. Active IgG4-RD, responder index >= 2 points
7. Stable condition less than one year.
8. Patient with two or more immunosuppressive agents.
9. Biological agents (such as CD20 monoclonal antibody and TNF-a inhibitor) have been used for half a year before admission.
10. Patient with IgG4-RD recurrence during hormone reduction in the past.