皮肌炎/多发性肌炎并发肺孢子虫肺炎的临床诊治

摘要

目的:总结皮肌炎/多发性肌炎(DM/PM)患者并发肺孢子虫肺炎(PCP)的诊治经过,提高对该病的认识.方法:对8例DM/PM患者(其中DM 6例、PM 2例)进行回顾性分析其并发PCP的危险因素、临床表现、影像学改变、治疗和转归.结果:8例患者中6例合并肺间质病变,均联合应用大剂量糖皮质激素和免疫抑制剂治疗.多数(6/8)诊断为DM/PM的患者在6个月内发生PCP,临床表现为发热、咳嗽和进行性呼吸困难;平均动脉血氧分压为44(40.7-66)mmHg(1 mmHg=0.133kPa);胸部影像学示双肺间质磨玻璃或多发弥漫斑片影.平均外周血淋巴细胞计数为0.46(0.16-0.76)×10(9)/L,平均CD4+T细胞计数为0.14(0.05-0.25)×10(9)/L.3例患者痰中、4例患者支气管肺泡灌洗液中找到肺孢子虫,3例患者痰中肺孢子虫聚合酶链反应(PCR)阳性;4例患者合并其他病原体感染.8例患者均应用复方磺胺异嗯唑和糖皮质激素治疗,死亡6例.结论:PCP为DM/PM患者少见,但其致命性、机会性感染在临床诊治时需提高警惕.%Objective To determine the clinical features and the prognosis of pneumocystis pneumonia (PCP) in human immunodeficiency virus ( HIV ) -free patients with dermatomyositis/polymyositis ( DM/PM ). Methods Retrospective analysis was used to investigate the clinical features and the outcome of PCP patients with DM/PM in single hospital. Results A total of 8 cases of PCP in patients with DM/PM were studied ( dermatomyositis, n = 6; polymyositis, n - 2 ). The majority of patients ( 6/8 patients, 75 % ) presented PCP during the first 6 months following the diagnosis of DM/PM. At the time of diagnosis of PCP, all patients were receiving corticosteroids plus immunosuppressive agents ( methotrexate, n = 8; cyclophosphamide, n -1; azathiopurine, n = 1; cyclosporine, n = 1). All patients were lymphocytopenic at the onset of PCP: the mean circulating lymphocytes count was 0. 46 (0. 16 ~0. 76) x 109/L, mean CD4+ lymphocyte count was 0. 14 (0. 05 ~0. 25) x 109/L The mean duration of prodromal symptoms was 10 days. Seventy-five percent patients required intensive care for respiratory failure. Mortality was high (6/8 patients, 75%). Conclusions PCP is an uncommon, but fatal opportunistic infection in patients with DM/PM. It must be considered in patients with DM/PM complicated with interstitial lung disease and receiving cytotoxic agents and corticosteroids, particularly if they have lymphocytopenia and/or CD4 +lymphocyte count less than 0.25 x 109/L Thus, induced sputum or bronchoalveolar lavage should be performed in patients with DM/PM when presenting with fever, pulmonary infiltrates, hypoxemia and lymphopenia.