Study on the Impact of Decolonization Treatment of Pneumocystis Jirovecii on the Frequency of Acute Exacerbation in COPD

Inclusion criteria

• Age 40 and above，male or female；
• COPD who meet the diagnostic criteria of the Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2026 ( post-bronchodilator FEV1/forced vital capacity [FVC] ratio < 0.7 and post-bronchodilator FEV1% predicted ≥ 30%), and have documented history of high exacerbation risk (Group E, defined as exacerbation history of ≥ 1 moderate or severe acute exacerbation within 12 months prior to inclusion)；
• Background triple therapy (ICS + LABA + LAMA) for 3 months prior to randomization with a stable dose of medication for ≥1 month prior to inclusion; Double therapy (LABA + LAMA) allowed if ICS is contraindicated；
• PCR detection of Pneumocystis jirovecii in induced sputum is positive；
• Informed consent

Exclusion criteria

• Allergic to TMP, SMX or sulfonamide drugs；
• There are pneumonia or other infections that require long-term use of antibacterial drugs (such as tuberculosis, NTM, other fungi, etc.)；
• Having used antibiotics within the previous 4 weeks prior to screening；
• Experience of AECOPD events within the previous 4 weeks prior to screening;
• Having a definite immunodeficiency disorder or receiving immunosuppressive therapy (such as HIV, agranulocytosis, solid organ or hematopoietic stem cell transplantation, malignant tumors, using long-term high-dose hormones > 20mg/day prednisone equivalent for more than 4 weeks)；
• Severe liver and kidney dysfunction (ALT/AST > 3 times the upper limit of normal value, eGFR < 60 mL/min/1.73m²)；
• Pregnant, lactating women or those planning to become pregnant;
• Folic acid deficiency-induced microcytic anemia;
• Currently using coumarin, phenytoin, pioglitazone, repaglinide, rosiglitazone, glipizide or glibenclamide;
• Currently participating in other interventional clinical studies；