Tofacitinib in the Treatment of Rheumatoid Arthritis-related Interstitial Lung Disease.

Inclusion Criteria:

1. Patients must fulfill ACR/EULAR 2010 RA classification criteria.
2. Patients must have an interstitial lung disease confirmed by a high-resolutioncomputed tomography scan or a surgical lung biopsy. Nonspecific interstitialpneumonia, usual interstitial pneumonia, lymphocytic pneumonia, and organizedpneumonia, either by HRCT or surgical biopsy, will be included.
3. Patients must be 18 years of age or older.
4. There is no evidence of active, latent, or inadequately treated infection withMycobacterium tuberculosis (TB).
5. Patients must discontinue using the non-permitted medications: leflunomide,azathioprine, cyclosporine, tacrolimus, cyclophosphamide, and any biologicdisease-modifying drug (bDMDARDs) such as anti-TNF therapy, rituximab, tocilizumab,etc. Patients must have a stable prednisone dose of ≤ 10 mg/ PO/day for at least threemonths.
6. All patients must have stable doses of prednisone during the last three months offollow-up, and the prednisone dose must be ≤ 10 mg/day. Patients without a prednisonehistory in the previous three months may also be included in the protocol.

Exclusion Criteria:

1. Seropositivity for the following infections: HIV, HBV, and HCV.
2. Absolute neutrophil count ≤ 1,200/L
3. Absolute platelet count ≤ 100,000 /L
4. Severe renal damage with GFR < 30 ml/min based on CKD-EPI formula.
5. AST or ALT greater than 1.5 times the upper limit of normal AST and ALT levels
6. Severe hepatic, hematologic, gastrointestinal, cardiac, and neurological disease mayput the patient´s life at risk regardless of ILD severity.
7. Severe active infections at baseline evaluation, such as pneumonia, urinary tractinfections, meningitis.

8 History of drug abuse or alcoholism. 9. History of any malignancy 10. Patients with anFVC < 40% of what is expected will be excluded from the study.