OBJECTIVE: To clarify the diagnostic value of sputum in pulmonary alveolar proteinosis (PAP) through transmission electron microscopy (TEM) of sputum deposition (SD). METHODS: Eleven SD samples and 9 bronchoalveolar lavage (BAL) sediments from a PAP group including 11 patients were observed by TEM and compared with sputum direct smear, BAL cytology, and lung biopsy histopathology. Eleven healthy adults were chosen as controls. RESULTS: The 11 sputum smears from the PAP group showed no diagnostic component, but TEM of SD revealed 7 of 11 samples had many myelin-like lamellar bodies with degeneration in the cytoplasm of macrophages, alveolar epithelial cells, and extracellular spaces, which suggested PAP. Especially, 2 patients on whom lung biopsy could not be performed and who failed to be diagnosed by BAL fluid were finally diagnosed by TEM of SD. TEM of BAL sediments showed 7 of 9 cases had diagnostic myelin-like lamellar bodies. No statistical significance was found between BAL fluid and SD by TEM. The control group didn't show diagnostic components by cytology or TEM of SD. CONCLUSION: TEM of SD is an important noninvasive diagnostic method especially for patients against lung biopsy and BAL.
OBJECTIVE: To clarify the diagnostic value of sputum in pulmonary alveolar proteinosis (PAP) through transmission electron microscopy (TEM) of sputum deposition (SD). METHODS: Eleven SD samples and 9 bronchoalveolar lavage (BAL) sediments from a PAP group including 11 patients were observed by TEM and compared with sputum direct smear, BAL cytology, and lung biopsy histopathology. Eleven healthy adults were chosen as controls. RESULTS: The 11 sputum smears from the PAP group showed no diagnostic component, but TEM of SD revealed 7 of 11 samples had many myelin-like lamellar bodies with degeneration in the cytoplasm of macrophages, alveolar epithelial cells, and extracellular spaces, which suggested PAP. Especially, 2 patients on whom lung biopsy could not be performed and who failed to be diagnosed by BAL fluid were finally diagnosed by TEM of SD. TEM of BAL sediments showed 7 of 9 cases had diagnostic myelin-like lamellar bodies. No statistical significance was found between BAL fluid and SD by TEM. The control group didn't show diagnostic components by cytology or TEM of SD. CONCLUSION: TEM of SD is an important noninvasive diagnostic method especially for patients against lung biopsy and BAL.