Differential distribution of lymphatic clearance between upper and lower regions of the lung
Article first published online: 25 JAN 2013
© 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology
Volume 18, Issue 2, pages 348–353, February 2013
How to Cite
EGASHIRA, R., TANAKA, T., IMAIZUMI, T., SENDA, K., DOKI, Y., KUDO, S. and FUKUOKA, J. (2013), Differential distribution of lymphatic clearance between upper and lower regions of the lung. Respirology, 18: 348–353. doi: 10.1111/resp.12006
- Issue published online: 25 JAN 2013
- Article first published online: 25 JAN 2013
- Accepted manuscript online: 2 NOV 2012 07:09AM EST
- Manuscript Accepted: 13 AUG 2012
- Manuscript Revised: 13 JUN 2012
- Manuscript Received: 24 JAN 2012
- Ministry of Health, Labor and Welfare, Japan
- diffuse lung disease;
- pulmonary fibrosis;
- pulmonary lymphatic;
- secondary lobule
Background and objective
Many lung diseases arise as the consequence of inhalational injury. When pathogenic materials are inhaled, it is possible that their clearance routes become the main focus of injury in the lung. Lymphatic clearance is important in the removal from the lung of small inhaled particles. The leak of toxic agents from the lymphatic flow potentially explains the topographic distribution of diffuse lung diseases triggered by inhaled materials, for example asbestosis. The aim of this study was to evaluate the differences in lymphatic distribution across various craniocaudal levels of the lung by using carbon dust deposition (CDD) as a tracing marker.
We evaluated 61 HE-stained slides of the normal lung area from 61 lobectomy specimens. The intensity of CDD was scored into five degrees (0–4) in bronchiolovascular (BV) areas and subpleural/septal (SP) areas per slide. The distribution was highlighted by subtraction scores of SP areas from those of bronchiolovascular areas.
The subtraction scores of the upper lung area were significantly greater than those in the lower area, whereas there was no significant difference in scores by pulmonary lobes.
Our results indicated that the main lymphatic clearance routes vary according to the craniocaudal levels, and are predominant in BV areas of the upper areas and in SP areas of the lower areas of the lung. This may explain the histological variations in anatomical distribution observed in the biopsy specimens of some diffuse lung diseases.