Cryptogenic organizing pneumonia (COP) after allogeneic hematopoietic stem cell transplantation (HSCT) is characterized by frequent recurrence. Few studies have examined onset and recurrence patterns of COP after HSCT. We investigated the clinical features of COP after HSCT in a single-center retrospective study including 165 consecutive patients who underwent allogeneic HSCT. Eighteen patients (11%) developed COP after HSCT. Hypoxemia and pleural effusion at the onset of COP were significantly associated with umbilical cord blood transplantation (P = 0.002 and P = 0.002, respectively). Recurrence of COP was observed in six patients and significantly associated with the presence of chronic graft-versus-host disease (cGVHD; P = 0.013) and stem cell sources other than umbilical cord blood (P = 0.038). Four patients with COP died of pulmonary failure after recurrence of COP. No patients who underwent umbilical cord blood transplantation experienced recurrence of COP. These findings suggest that the clinical features at the onset of COP may depend on stem cell sources. Moreover, both stem cell source and the absence or presence of cGVHD may affect COP recurrence, indicating the need to develop treatment strategies against COP according to stem cell source and risk of cGVHD.

中文翻译：

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异基因造血干细胞移植后隐源性组织性肺炎的发作和结局模式。

异基因造血干细胞移植（HSCT）后的隐源性组织性肺炎（COP）的特点是复发频繁。很少有研究检查HSCT后COP的发作和复发模式。我们在一项单中心回顾性研究中调查了HSCT后COP的临床特征，该研究包括165位连续接受异体HSCT的患者。HSCT后有18例患者（11％）发生了COP。COP发作时的低氧血症和胸腔积液与脐带血移植显着相关（分别为P = 0.002和P = 0.002）。在6例患者中观察到COP复发，并与慢性移植物抗宿主病（cGVHD； P = 0.013）和脐带血以外的干细胞来源（P = 0.038）显着相关。4例COP患者在COP复发后死于肺衰竭。没有进行过脐带血移植的患者出现了COP复发。这些发现表明，COP发作时的临床特征可能取决于干细胞来源。此外，干细胞来源和cGVHD的缺乏与否都可能影响COP复发，表明需要根据干细胞来源和cGVHD的风险制定针对COP的治疗策略。