Department of Pathology and Molecular Medicine, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic.
Prague Lung Transplant Program, 3rd Department of Surgery, 1st Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic.
Pathol Res Pract. 2022 Sep;237:154060. doi: 10.1016/j.prp.2022.154060. Epub 2022 Aug 5.
It has been postulated that platelets are produced by fragmentation of the megakaryocytes within the pulmonary circulation rather than budding of their cytoplasm within the bone marrow. Although literature is scarce depicting the levels of the megakaryocytes within the lungs from previously healthy individuals, there are several studies describing the presence of these cells in human necropsy specimens, and it has been hypothesized that their rearrangements could contribute to the pathogenesis of chronic pulmonary vascular disorders. The objective of this study was to describe the characteristics, distribution and total count of megakaryocytes in explants from lung transplant (LTx) recipients based on the final clinicopathological diagnosis, as well as in samples from LTx donors without previously known pulmonary disease. Using the immunohistochemical marker CD61 we quantified and characterized such cells in 20 biopsy samples from LTx donors and in 30 biopsy samples from LTx recipients with different pathologic conditions: vascular disorders of the lungs, obstructive pulmonary disorders and fibrotic lung diseases. Patients suffering from idiopathic pulmonary arterial hypertension (IPAH) showed morphological differences and strikingly higher numbers of the lungs megakaryocytes (264.5 cells/cm) compared to all the other groups (the average count among donors was 33.55 megakaryocytes/cm). Such finding could contribute to the understanding of the origin of vasoconstriction, thrombosis and vascular remodeling of the pulmonary circulation - all the basic mechanisms leading to the development of IPAH, as for there is an increasing evidence of several products of platelets and megakaryocytes to be capable of triggering such processes.
有人假设血小板是由肺循环中的巨核细胞碎裂产生的，而不是由骨髓中的细胞质芽生产生的。尽管文献中很少有描述来自以前健康个体的肺部巨核细胞水平的资料，但有几项研究描述了这些细胞在人体尸检标本中的存在，并假设它们的重排可能有助于慢性肺血管疾病的发病机制。本研究的目的是描述基于最终临床病理诊断的肺移植（LTx）受者肺移植标本中巨核细胞的特征、分布和总数，以及来自无先前已知肺部疾病的 LTx 供体的标本。使用免疫组织化学标志物 CD61，我们对 20 例 LTx 供体活检样本和 30 例具有不同病理状况的 LTx 受者活检样本中的这些细胞进行了定量和特征描述：肺部血管疾病、阻塞性肺疾病和纤维化性肺部疾病。患有特发性肺动脉高压（IPAH）的患者表现出形态学差异，并且肺部巨核细胞数量明显更高（264.5 个细胞/cm），与所有其他组相比（供体的平均计数为 33.55 个巨核细胞/cm）。这种发现有助于理解肺血管收缩、血栓形成和血管重塑的起源——所有导致 IPAH 发展的基本机制，因为越来越多的证据表明血小板和巨核细胞的几种产物能够触发这些过程。
