Elemental analysis of lung tissue particles and intracellular iron content of alveolar macrophages in pulmonary alveolar proteinosis
Elemental analysis of lung tissue particles and intracellular iron content of alveolar macrophages in pulmonary alveolar proteinosis
复制标题
肺泡蛋白沉积症肺组织颗粒元素分析及肺泡巨噬细胞胞内铁含量
作者：
Y. Shimizu;S. Matsuzaki;K. Dobashi;N. Yanagitani;T. Satoh;M. Koka;A. Yokoyama;T. Ohkubo;Y. Ishii;T. Kamiya;M. Mori
肺泡蛋白沉积症（pulmonary alveolar proteinosis，PAP）是一种罕见的疾病，可由自身免疫性疾病或吸入性疾病引起.空气中微粒诱导X射线发射（空气中微PIXE）系统通过质子微束照射对材料进行元素分析，并允许以非常低的背景噪声对各种元素的空间分布和定量进行可视化。本研究的目的是评估继发性PAP由于吸入有害颗粒，采用在空气中的微粒和细胞内铁的石蜡包埋的肺组织标本从PAP患者与正常肺组织从非PAP患者相比，在PIXE分析。结果空气中微量PIXE分析可确定肺泡巨噬细胞内铁颗粒的组成元素及其位置，包括镁（Mg）、铝（Al）、硅（Si）、磷（P）、硫（S）、钪（Sc）、钾（K）、钙（Ca）、钛（Ti）、检测铬（Cr）、铜（Cu）、锰（Mn）、铁（Fe）和锌（Zn）。Si是颗粒的主要成分。柏林蓝染色的连续切片显示吞噬颗粒的铁巨噬细胞蓄积。空气中微量PIXE分析和柏林蓝染色结果显示，PAP肺泡巨噬细胞表面富铁区细胞内铁含量均高于对照肺正常组织。通过对石蜡包埋肺组织切片同时进行二维和元素分析来确定单细胞的细胞内铁含量。结果表明，继发性PAP与暴露于吸入颗粒物和肺泡巨噬细胞中铁的积累有关。
BackgroundPulmonary alveolar proteinosis (PAP) is a rare disease occurred by idiopathic (autoimmune) or secondary to particle inhalation. The in-air microparticle induced X-ray emission (in-air micro-PIXE) system performs elemental analysis of materials by irradiation with a proton microbeam, and allows visualization of the spatial distribution and quantitation of various elements with very low background noise. The aim of this study was to assess the secondary PAP due to inhalation of harmful particles by employing in-air micro-PIXE analysis for particles and intracellular iron in parafin-embedded lung tissue specimens obtained from a PAP patient comparing with normal lung tissue from a non-PAP patient. The iron inside alveolar macrophages was stained with Berlin blue, and its distribution was compared with that on micro-PIXE images.ResultsThe elements composing particles and their locations in the PAP specimens could be identified by in-air micro-PIXE analysis, with magnesium (Mg), aluminum (Al), silicon (Si), phosphorus (P), sulfur (S), scandium (Sc), potassium (K), calcium (Ca), titanium (Ti), chromium (Cr), copper (Cu), manganase (Mn), iron (Fe), and zinc (Zn) being detected. Si was the major component of the particles. Serial sections stained by Berlin blue revealed accumulation of sideromacrophages that had phagocytosed the particles. The intracellular iron content of alveolar macrophage from the surfactant-rich area in PAP was higher than normal lung tissue in control lung by both in-air micro-PIXE analysis and Berlin blue staining.ConclusionThe present study demonstrated the efficacy of in-air micro-PIXE for analyzing the distribution and composition of lung particles. The intracellular iron content of single cells was determined by simultaneous two-dimensional and elemental analysis of paraffin-embedded lung tissue sections. The results suggest that secondary PAP is associated with exposure to inhaled particles and accumulation of iron in alveolar macrophages.