Investigators have developed a new Composite Physiologic Index (CPI) that more effectively shows the structural extent of pulmonary fibrosis in patients and provides a more accurate prognostic indicator for interstitial pneumonia. British investigators devised a formula to fit pulmonary function test results against disease extent as measured by computed tomography (CT) in 212 patients. They divided the group into two sections of 106 each, and developed the formula in one group, then tested it in the other. During the development of pulmonary fibrosis, as a byproduct of certain diseases or agents, white blood cells and protein-rich fluid accumulate in the air sacs (alveoli) of the lungs, causing inflammation. If the inflammation persists, the fluid may solidify. Then scarring or fibrosis replaces lung tissue. The developers of the index said that the new CPI correlates with the extent of pulmonary fibrosis on CT more strongly and is linked to mortality more closely than individual pulmonary function indices. The researchers added that the CPI quantifies the functional deficits attributable to pulmonary fibrosis while excluding those attributable to emphysema. This latter illness was present in over 20 percent of the patients, and confounds other methods of quantifying disease extent. The CPI also turned out to be an excellent prognostic indicator in 36 patients with interstitial pneumonia. The study is published in the first issue of April 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
STEM CELLS MAY BE POSSIBLE FUTURE TREATMENT FOR ACUTE LUNG INJURY
One approach to future treatment of acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome (ARDS), could be stem cells to replace dying lung cells, according to a summary report from a panel of experts looking at future research directions in acute lung injury. ALI and ARDS are syndromes with a spectrum of increasing severity associated with lung injury. Usually constituting a very serious medical emergency, ARDS is a type of lung failure that results from disorders causing pulmonary edema or fluid accumulation in the lungs. There is a 30 to 40 percent chance of death associated with ARDS. In the bone marrow, all blood cells originate from a single type of cell called a stem cell. Stem cells divide and take different developmental pathways that result in different types of blood cells and platelets. While the experts point out that a better understanding of stem cell release, targeting, proliferation, and differentiation in lung tissue is needed, intravenous infusion of donor bone-marrow derived stem cells might be useful in ALI/ARDS in the future. The panelists said that newly implanted endothelial cells could help restore the lung capillary network after ALI; although they felt considerable work would be needed to develop approaches for the delivery of viable cells to injured areas of the lungs. The report with all its recommendations is published in the first issue for April 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
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Journal
American Journal of Respiratory and Critical Care Medicine