Airways microbiota: Hidden Trojan horses in asbestos exposed individuals?

Malignant pleura mesothelioma (MPM) is a rare type of cancer with devastating prognosis, which develops in the pleural cavity from transformed mesothelium. MPM has been directly associated with asbestos exposure however there are aspects of the pathophysiology involved in the translocation of asbestos fibers in the pleura that remain unclear. Here, we propose and discuss that certain proteins secreted by airways symbiotic microbiota create membrane pores to the airway epithelial cells, through which asbestos fibers can penetrate the lung parenchyma and reach the sub-pleural areas. We evaluate this hypothesis using data from the published literature regarding the airways microbiota toxins such as cholesterol-dependent cytolysins (CDCs).

Extrapleural pneumonectomy for pyothorax-associated lymphoma.

Pyothorax-associated lymphoma (PAL) is a non-Hodgkin's lymphoma that occurs in the pleural cavity of patients with a long-standing history of pyothorax. Here, we report a left pleuropneumonectomy performed for PAL in a 76-year-old male patient with a 60-year history of pyothorax due to tuberculosis.

Co-existent cutaneous cryptococcosis of the forearm and cutaneous alternariosis of the leg in patient with metastatic thymoma.

BACKGROUND: Cryptococcosis and alternariosis are rare opportunistic infections often observed in immunocompromised patients. Because Cryptococcus and Alternaria are ubiquitous fungi found in soil, the presence of fungi in the dermis has to be observed on histological examination to confirm a real cutaneous, invasive, infection. PATIENT: We report the first case of concomitant cutaneous cryptococcosis and cutaneous alternariosis, in an immunocompromised patient treated for a metastatic thymoma. CONCLUSION: This observation underlines the fact that the possible co-existence of several rare infections in immunocompromised patients should take into consideration pathogen identification in order to adapt the therapy to individual patient requirements.

Simian virus 40-like DNA sequences in human pleural mesothelioma.

Mesotheliomas are pleural, pericardial, or peritoneal neoplasms frequently associated with asbestos exposure, and it is estimated that over the next twenty years up to 80,000 new cases are expected in the USA alone. We found simian virus 40-like DNA sequences in 29 of 48 mesotheliomas studied (60%) and demonstrated simian virus large-T antigen expression in 13 of 16 specimens. The matching lung samples did not contain simian virus 40-like sequences; however, they contained asbestos. These findings are to our knowledge the first demonstration of a physical link between DNA virus-like sequences and human mesothelioma. We suggest that a simian virus 40-like virus may act independently or as a co-carcinogen with asbestos. Moreover, the selective large T antigen expression by mesothelioma and not by the surrounding pulmonary parenchyma may have both diagnostic and therapeutic implications.

Epstein-Barr virus in pyothorax-associated pleural lymphoma.

Pleural B-cell lymphoma was found in five patients with a history of pyothorax that was the sequelae of tuberculosis 35 to 47 years previously. Epstein-Barr virus (EBV) DNA was detected in all five pleural tumors by polymerase chain reaction and Southern blot hybridization. The lymphoma cells were shown to express the latent membrane protein-1 and the EBV-encoded nuclear antigen-2 by immunocytochemistry and EBV-encoded small RNA by in situ hybridization. Three cases were shown to be EBV subtype A, whereas the remaining two were subtype B, as determined by differences in the EBV-encoded nuclear antigen-2 nucleotide sequence. The patients also had high titers of antibodies against EBV. These findings suggest that EBV is causally associated with the pleural lymphomas that originate at the site of chronic inflammation and fibrosis with a latent period of more than 40 years.