title: [The ultrastructural features of sputum deposition and its value in the diagnosis of pulmonary alveolar proteinosis].
abstract: OBJECTIVE
  To investigate the ultrastructural features of sputum deposition (SD) and its value in the diagnosis of pulmonary alveolar proteinosis (PAP).
  
  
  METHODS
  Seven patients with PAP diagnosed by lung biopsy and cytology were enrolled in this study. The patients consisted of 5 men and 2 women, whose median age was 48 years (range 36 to 73). SD and bronchoalveolar lavage fluid (BALF) sediment were made into ultrathin sections and observed under transmission electron microscope (TEM), respectively. Seven cases of control group composed of 4 men and 3 women whose median age was 49 years (range 39 to 68) including 3 cases of bacterial pneumonia, two cases of COPD and 2 cases of exudative pulmonary tuberculosis. Each SD was made into ultrathin section, and compared with the experimental group.
  
  
  RESULTS
  In PAP group, Periodic acid-schiff (PAS) staining was performed on 7 sputum smears and none of them was tested positive for any components with diagnostic interest. Four cases from the 7 paraffin-embed sections of BALF sediment by microscopic examination suggested PAP. Under TEM, BALF sediment showed that many lamellar bodies existed in and outside alveolar epithelial cells, and 5 specimens were consistent with PAP diagnosis. Compared with BALF sediment, SD had apparent degeneration with more myelin phagosomes in the cytoplasm of macrophages, more lamellar bodies in alveolar epithelial cells, and lots of lamellar bodies in the shape of concentric circle in the extracellular spaces. Four from the 7 SD samples were consistent with the diagnosis of PAP. No significant difference was found between SD and BALF in the diagnosis of PAP by electronic examination (P > 0.05). In the 7 cases of control group no drifting osmiophilic lamellar bodies in extracellular space were detected.
  
  
  CONCLUSIONS
  The osmiophilic lamellar bodies with diagnostic value were found in SD and BALF of patients with PAP. TEM of SD in combination with clinical manifestations and radiologic findings can make a definitive diagnosis of PAP, especially for those patients who have contraindications to lung biopsy and lung lavage.
authors: Department of Special Examination, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai 200433, China.
authors: Ben-fang
authors: BF
authors: Luo
authors: Hui-ping
authors: HP
authors: Li
authors: Xiang-hua
authors: XH
authors: Yi
authors: Ju-wei
authors: JW
authors: Tao
authors: Han-jing
authors: HJ
authors: Lü
authors: Xia
authors: X
authors: Fang
authors: Zong-mei
authors: ZM
authors: Zhang
authors: Long
authors: L
authors: Zhang
authors: Sheng-xiang
authors: SX
authors: Ren
authors: Hai-qing
authors: HQ
authors: Chu
authors: Xia
authors: X
authors: Li
authors: Yu
authors: Y
authors: Zeng
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D001992:Bronchoalveolar Lavage Fluid; D016022:Case-Control Studies; D003581:Cytodiagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011649:Pulmonary Alveolar Proteinosis / Q000175:diagnosis* / Q000473:pathology*; D013183:Sputum / Q000737:chemistry*