風濕性疾病患者之需要機械通氣的肺囊蟲肺炎的預後與相關因素之探討

Outcomes and Prognostic Factors related to Pneumocystis Pneumonia Requiring Mechanical Ventilation in Patients with Rheumatic Diseases

目的：探討風濕性疾病患者之需要機械通氣的肺囊蟲肺炎的臨床特徵、預後與相關因素。方法：我們針對西元2015年10月至2018年10月之間，發生於一間醫學中心的風濕性疾病患者之需要機械通氣的肺囊蟲肺炎進行病歷回顧。肺囊蟲肺炎的診斷需要陽性的Pneumocystis jirovecii PCR痰液檢體、肺囊蟲肺炎的臨床症狀和影像學發現。我們評估了臨床表現、原本的風濕性疾病、共病症、免疫抑制劑與預後，並使用Cox proportional-hazards model進行預後的相關因素分析。結果：在研究期間有27位需要機械通氣的肺囊蟲肺炎的風濕性疾病患者，平均年齡為57.4歲，有13位（48%）是女性。原本的風濕性疾病主要有全身性紅斑狼瘡（26%）、類風濕性關節炎（22%）、抗磷脂質症候群（15%）及特發性發炎性肌肉病變（15%）。有19位（70%）患者在住院中死亡，並依其死亡結果分成存活組和非存活組進行分析。非存活組有比較短的原本的風濕性疾病病程（4 vs. 124個月，p＝0.049）、比較高的輔助性類固醇劑量（50.0 vs. 33.8 mg／day，p＝0.012）及比較高的比率有使用過Cyclophosphamide（63％vs. 13%，p＝0.033）。使用多變項的Cox proportional-hazards regression分析，有使用過Cyclophosphamide是住院中死亡的獨立相關因子（hazard ratio, 2.77；95％confidence interval＝1.02 to 7.54；p＝0.045）。結論：風濕性疾病患者之需要機械通氣的肺囊蟲肺炎的住院中死亡，與有使用過Cyclophosphamide相關。

Objective: To investigate the clinical features, outcomes, and prognostic factors related to Pneumocystis pneumonia (PCP) requiring mechanical ventilation in patients with rheumatic diseases. Methods: We reviewed the medical records of all subjects with rheumatic diseases and PCP requiring mechanical ventilation between October 2015 and October 2018 at a tertiary referral center. PCP was diagnosed via a positive sputum Pneumocystis jirovecii polymerase chain reaction test, clinical symptoms, and radiographic findings. Clinical manifestations, underlying rheumatic diseases, comorbidities, use of immunosuppressants, and outcomes were evaluated. The Cox proportional-hazards model was used to identify prognostic factors related to mortality. Results: During the study period, 27 patients [mean age, 57.4 years; 13 (48%) females] with rheumatic diseases and PCP requiring mechanical ventilation were enrolled. The most common underlying rheumatic diseases included systemic lupus erythematosus (26%), rheumatoid arthritis (22%), antiphospholipid syndrome (15%), and idiopathic inflammatory myopathies (15%). All subjects were categorized into survivors and non-survivors, with 19 (70%) patients ultimately expiring during hospitalization. Non-survivors had a shorter underlying rheumatic disease duration (4 vs. 124 months; p = 0.049), higher adjunctive glucocorticoid dose (50.0 vs. 33.8 mg/day; p = 0.012), and higher rate of previous cyclophosphamide exposure (63% vs. 13%; p = 0.033) compared to survivors. Multivariate Cox proportional-hazards regression analysis identified previous cyclophosphamide exposure to be an independent factor associated with in-hospital mortality (hazard ratio, 2.77; 95% confidence interval, 1.02 to 7.54; p = 0.045). Conclusions: Previous cyclophosphamide exposure was associated with in-hospital mortality among patients with rheumatic diseases and PCP requiring mechanical ventilation.