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

Previous researches have found the common colonization of Pneumocystis jirovecii (Pj) in the airways of people with chronic obstructive pulmonary disease (COPD). And this colonization may exacerbate airway inflammation and increase the frequency of acute exacerbation in people with COPD. The goal of this clinical trial is to study if "decolonization treatment" (that is, removing these colonizing Pj) works to improve the prognosis of COPD colonized by Pj in adults. The main question it aims to answer is: * Does the Trimethoprim-Sulfamethoxazole (TMP-SMX, an antibiotics) decolonization treatment reduce the frequency of acute exacerbation in participants with COPD colonized by Pj who have a high risk of acute exacerbation. Researchers will compare TMP-SMX to a placebo (a look-alike substance that contains no drug) to see if TMP-SMX works to reduce the frequency of acute exacerbation of COPD. Participants will: * Take drug TMP-SMX or a placebo 2 tablet every day for 4 weeks. * Visit the clinic after 2 weeks, 1 month, 3 months, 6 months and 12 months for survey questions, checkups and tests. * Keep a diary of their symptoms and the number of times they experience acute exacerbations

NCT Number	NCT07665359
Lead Sponsor	Second Affiliated Hospital, School of Medicine, Zhejiang University Collaborators: First Affiliated Hospital of Zhejiang University, Zhejiang Rongjun Hospital, Zhejiang Quhua Hospital, West China Hospital, Shanghai Pulmonary Hospital, Shanghai, China, Second Affiliated Hospital of Nanchang University, Shanghai Tongji Hospital, Tongji University School of Medicine, Huzhou Central Hospital, Shaoxing People's Hospital, Affiliated Hospital of Jiaxing University, Red Cross Hospital, Hangzhou, China, Taizhou Hospital, Taizhou Hospital of Zhejiang Province affiliated to Wenzhou Medical University, The First Affiliated Hospital of Guangzhou Medical University, First Affiliated Hospital of Wenzhou Medical University, Zhejiang Hospital, Sir Run Run Shaw Hospital, The Fifth Affiliated Hospital of Wenzhou Medical University & Lishui Central Hospital, Tongji Hospital, The Sixth Affiliated Hospital of Wenzhou Medical University
Conditions	Chronic Obstructive Pulmonary Disease (COPD)
Enrollment	630 participants
Start Date	2026-07-01
Primary Completion	2029-05-01 (estimated)
Study Completion	2029-05-01 (estimated)
Updated on ClinicalTrials.gov	2026-06-24