BACKGROUND AND OBJECTIVE Recently the term "interstitial pneumonia with autoimmune features" (IPAF) has been proposed to identify patients with interstitial lung disease and autoimmune characteristics, not fulfilling the criteria for specific connective tissue diseases (CTD). Only few data are available about the clinical and serological features of IPAF patients, their survival and the possible evolution in a CTD. The aims of the study were to investigate the demographic and clinico-serologic features of patients with IPAF, their relationship to survival, and the possible evolution in a definite CTD. PATIENTS AND METHODS Fifty-two patients were consecutively enrolled and prospectively followed for 45 ± 31.6 months. Data about disease onset, serological, clinical and therapeutic features, pulmonary function tests and high-resolution computed tomography were periodically repeated. The survival of patients with IPAF was compared with that of 104 patients with idiopathic pulmonary fibrosis (IPF). RESULTS The clinical domain for IPAF was satisfied in 44 patients, serological domain in 49 and the morphological domain in 29 patients. During the follow-up, a definite CTD was diagnosed in 7 patients, in particular Sjogren's syndrome in 4 patients, rheumatoid arthritis in 2, and polymyositis in the last. The estimated 5-year survival of IPAF patients 69.5 ± 7.8%, significantly higher than survival observed in IPF patients, and the baseline value of FVC and DLCO were the only factors associated to death. CONCLUSIONS IPAF seems to a distinct entity, with a low tendency to evolve in a definite CTD. Nevertheless, further studies are needed to better define the clinical evolution and the outcome of IPAF.

中文翻译：

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具有自身免疫特征的间质性肺炎：单中心前瞻性随访研究。

背景和目的近来，已经提出了术语“具有自身免疫特征的间质性肺炎”（IPAF）来鉴定患有间质性肺疾病和自身免疫特征的患者，其不满足特定结缔组织疾病（CTD）的标准。关于IPAF患者的临床和血清学特征，他们的生存以及CTD中可能的演变，只有很少的数据。这项研究的目的是调查IPAF患者的人口统计学和临床​​血清学特征，其与生存的关系以及在确定的CTD中可能的演变。患者与方法连续入组52例患者，前瞻性随访45±31.6个月。有关疾病发作，血清学，临床和治疗特征的数据，定期重复进行肺功能检查和高分辨率计算机断层扫描。将IPAF患者的生存与104例特发性肺纤维化（IPF）患者的生存进行了比较。结果IPAF的临床领域为44例，血清领域为49例，形态学领域为29例。在随访期间，确诊7例CTD，特别是干燥综合征4例，类风湿关节炎2例，多发性肌炎。IPAF患者的5年生存率估计为69.5±7.8％，明显高于IPF患者的生存率，而FVC和DLCO的基线值是唯一与死亡相关的因素。结论IPAF似乎是一个独立的实体，在确定的CTD中发展的趋势很低。尽管如此，