Efficacy and Safety of Prophylactic Treatment for Pneumocystis Jirovecii Pneumonia in Patients With Autoimmune Inflammatory Rheumatic Disease

Inclusion Criteria: 1. The patient was diagnosed with AIIRD according to the International Classification of Diseases and had received steroids or immunosuppressive therapy; 2. The patient had not received standard PJP treatment before enrollment, including the first-line treatment drug TMP/SMZ, or other second-line treatment drugs (including Pentamidine, Atorvastatin, Caspofungin, etc.); 3. The patient was at least 18 years old at the time of enrollment; Exclusion Criteria: 1. Serious health problems or diseases, including (but not limited to) the following: severe liver damage (ALT, AST elevated above normal value by more than 5 times), severe renal insufficiency (GFR \< 30mL/min or Scr \> 445umol/L), severe myelosuppression (Hb \< 65g/L, PLT \< 25×10\^9/L or neutrophils \< 0.5×10\^9/L); 2. Screening test indicates infection with human immunodeficiency virus (HIV), history of lymphomatous hyperplasia of the lymphatic tissue or any malignant tumor of any organ system within the past 5 years, or history of organ transplantation; 3. Participants with a history of allergy to sulfonamide drugs, megaloblastic anemia due to folate deficiency; 4. Pregnant and lactating women; 5. Any medical or psychological condition that the investigator believes would interfere with the participant's ability to comply with the protocol or complete the study; 6. Patients who refuse to comply with the requirements of this study and complete the study; 7. Any other situation that the investigator considers unsuitable for participation in the study (for reasons including but not limited to management reasons).