[Clinical analysis of autoimmune diseases associated with interstitial lung diseases initially presented with idiopathic pulmonary fibrosis].

Objectives: To describe the clinical characteristics of patients with autoimmune diseases associated interstitial lung diseases (AID-ILD) initially presented with idiopathic pulmonary fibrosis (IPF) in a tertiary Chinese hospital. Methods: We conducted a retrospective analysis of 14 patients diagnosed with AID-ILD during the IPF follow-up between January 2016 and December 2021. Among the 14 enrolled AID-ILD cases, there were 13 males and 1 female, (69.71±9.07) years old (range from 55 y to 87 y). Results: Detailed clinical consultation and further laboratory analysis were performed during the follow-up when the IPF patients showed exaggerated dyspnea (7 cases), fever of unknown causes (6 cases), microscopic hematuria (5 cases), arthralgia and swelling (4 cases), arthralgia (2 cases), morning stiffness (2 cases) and renal failure (2 cases). Finally, 6 patients showed positive MPO-ANCA, one patient showed positive PR3-ANCA and 7 patients showed positive anti-CCP. During the IPF periods, 7 patients had received antifibrotic agents and 5 patients had been prescribed with N-acetylcysteine, and 1 patient had received antifibrotic agents after N-acetylcysteine. Among them, no medication was prescribed for one IPF patient. After they were diagnosed with AID-ILD, glucocorticoids and/or immunosuppressants were added for 13 of them. Thirteen of cases improved or stable after these treatments, but one didn't show significant changes. Conclusions: AID-UIP, especially ANCA-UIP, AAV-UIP or RA-UIP should be considered when the IPF patients showed fever of unknown origin, microscopic hematuria and/or arthritis related symptoms. They might benefit from the add-on glucocorticoids and/or immunosuppressants.目的： 总结以特发性肺纤维化（IPF）起病的自身免疫性疾病相关性间质性肺疾病（AID-ILD）患者的临床特征，提高临床医生对此类疾病的认识。 方法： 回顾性纳入2016年1月至2021年12月北京协和医院就诊的、以IPF起病的14例AID-ILD患者，分析其临床资料，其中男13例，女1例，年龄55~87（69.7±9.1）岁。总结诊疗过程以及疗效。 结果： 所有患者均在确诊IPF后规律随访，因出现以下临床表现进一步筛查发现AID：气短加重7例、发热6例，镜下血尿5例，关节肿痛4例，关节痛、晨僵、肾功能不全2例。最终诊断髓过氧化物酶抗体（MPO）-中性粒细胞胞质抗体（ANCA）阳性6例，抗蛋白酶3抗体（PR-3）-ANCA阳性1例，抗环瓜氨酸肽阳性7例。在最初诊断为IPF阶段，7例接受抗纤维化药物治疗，5例使用N-乙酰半胱氨酸，1例使用N-乙酰半胱氨酸后加用抗纤维化药物，1例患者未接受药物治疗。诊断AID-ILD后，1例继续吡非尼酮治疗，其余均加用了激素和（或）免疫抑制剂；调整治疗方案后，13例患者病情均好转或稳定。 结论： IPF患者出现发热、镜下血尿以及关节炎的相关表现时，需要警惕AID-ILD可能，尤其是ANCA相关性寻常型间质性肺炎（UIP）、ANCA相关性血管炎-UIP和类风湿关节炎相关性-UIP；加用激素和（或）免疫抑制剂治疗可能使其获益。.