The migration of the asbestos fibers out of the alveoli is a function of the small size of the fibers. This allows them to pierce the cell walls and migrate between cell boundaries into the mesothelial lining of the pleural cavity or even into the intrapleural space after asbestos exposure occurs. There, they sometimes penetrate the diaphragm and make their way into the abdomen or the testes.
Mesothelioma Development through the Inflammatory Response
Whenever these fibers migrate, they leave a trail of damaged or compromised cells behind. The inflammatory response includes the migration of both macrophages and mesothelial cells to the affected area. It has now been described that these cells secrete substances which contribute to cell survival and permit cell division rather than programmed cell death as is the case when damaged cells are detected by the body’s natural surveillance system. These damaged cells now acquire a survival advantage and can transform into malignant mesothelioma.
The response to this damage varies by individual and invariably involves the immune system. Evidence for the response is found in the irritation and destruction of cells and the creation of scar tissue at the site of the injury, resulting from exposure to asbestos. This process can be quite significant in the case of heavy asbestos exposure and can lead to major impairment of the lungs as a crust or plaque of fibrous scar tissue forms over the affected areas. Microscopic examination of this material has often found asbestos fibers entombed in the nodules and layers of tissue and has been used as prima fascia evidence for the asbestos connection as a cause of mesothelioma.
For more information on the development of mesothelioma, read the following articles:
Differential effects of malignant mesothelioma cells on THP-1 monocytes and macrophages.
Acute injury and regeneration of the mesothelium in response to asbestos fibers.
