自體免疫風濕病患者罹患肺囊蟲肺炎的危險因子：台灣全民健保資料庫的配對病例對照研究

Risk Factors for Pneumocystis Jirovecii Pneumonia in Patients Diagnosed with Autoimmune Rheumatic Diseases: A Matched Case-control Study from the Taiwan National Health Insurance Database

目的：研究自體免疫風濕病患者(ARDs)患者罹患肺囊蟲肺炎(PJP)的危險因子。
方法：依據台灣全民健康保險資料庫(NHIRD)的數據，這項回顧性病例對照研究分析了82,744名ARDs患者，包括全身性紅斑狼瘡(SLE)、類風濕性關節炎(RA)、修格蘭氏症(SS)、多發性肌炎和皮肌炎(PM/DM)患者。根據年齡和性別，PJP患者與1681名非PJP患者匹配，比例為1:40（PJP，n=41；非PJP，n=1,640）。採用傾向性分數匹配(PSM)以減少偏差，最終選擇了120名患者（PJP，n=40；非PJP，n=80）。分析了臨床特徵以及藥物使用狀況，以確認PJP的危險因子。
結果：在PSM之前，PJP患者表現出較低的收入和較長的住院時間(p<0.05)。藥物使用，包括滅殺除癌(MTX)、環孢靈(Cyclosporin)、癌德星(CYC)和睦體康(MMF)，與增加PJP風險存在顯著關聯(p<0.05)。在PSM匹配之後，在藥物類別變相方面，可以看到MTX和MMF的使用明顯增加了PJP的風險(p<0.05)。而在藥物連續變相方面，MTX和類固醇的使用的增加與PJP風險較高顯著相關(p<0.05)。
結論：本研究顯示，特定藥物，尤其是MTX、MMF和類固醇，與ARDs患者中PJP感染風險有較高的相關姓。但這是一項回顧性病例對照研究，樣本大小相對較小，且僅依賴PSM可能無法完全減輕樣本選擇中的偏差，RA病人使用MTX也可能被併用的類固醇所影響，因此需要後續更多的研究。

Introduction: Pneumocystis jirovecii pneumonia (PJP) is a significant opportunistic fungal infection affecting the lungs, particularly in immunocompromised individuals. While much research has focused on PJP in contexts such as HIV infection and organ transplantation, there are few studies in the available literature regarding its association with autoimmune rheumatic diseases (ARD). This study aims to investigate the risk factors for PJP in ARD patients, with the specific focus being on immunosuppressive medications, so as to provide better insight into the necessary preventive strategies.
Materials and Methods: Using data taken from Taiwan's National Health Insurance Research Database (NHIRD), this retrospective case-control study analyzed 82,744 ARD patients, including those with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjogren's syndrome (SS), polymyositis and dermatomyositis (PM/DM). PJP patients were matched with 1,681 non-PJP patients based upon age and gender at a ratio of 1:40 (PJP, n=41; Non-PJP, n=1,640). Propensity score matching (PSM) at a ratio of 1:2 was employed to reduce bias, with an eventual 120 patients ultimately being selected (PJP, n=40; Non-PJP, n=80). Demographic and clinical characteristics, as well as medication usage, were all analyzed in order to identify risk factors for PJP.
Results: Prior to performing PSM, patients with PJP had exhibited lower incomes and longer hospitalization durations (p<0.05). Medication use, including methotrexate (MTX), cyclosporin, cyclophosphamide (CYC) and mycophenolate mofetil (MMF) revealed that there was a significant association with an increased risk of PJP (p<0.05). After PSM, the use of MTX and MMF significantly increased the risk of PJP (p<0.05). Regarding continuous variables for drugs, an increased usage of MTX and steroids was significantly associated with a higher risk of PJP (p<0.05) after adjusting for confounding factors.
Conclusion: This study demonstrated that certain medications, particularly MTX, MMF and steroids, were each associated with a higher risk of PJP infection in ARD patients.