Relationship of inflammatory cell cytokines to disease severity in individuals with occupational inorganic dust exposure

Abstract

The pneumoconioses due to chronic occupational exposure to asbestos, coal, or silica are characterized by an alveolar macrophage-dominated alveolitis with exaggerated spontaneous release of mediators: oxidants, chemotaxins for neutrophils, and fibroblast growth factors. Bronchoalveolar lavage was performed on 66 non-smoking inorganic dust-exposed individuals with a chest x-ray greater than or equal to 1/0 stratified by presence or absence of restrictive respiratory impairment, and 28 unexposed non-smoking controls. Both dust-exposed groups stratified by presence or not of impairment had increased numbers of total cells recovered by lavage compared to normals, and those with respiratory impairment (n = 40) had a significant increase in percent and number of neutrophils recovered. Similarly, only those with respiratory impairment had macrophages that spontaneously released significant amounts of the oxidants superoxide anion and hydrogen peroxide. There was a significant trend for the release of fibronectin by macrophages from controls to dust-exposed without impairment to those with impairment. Both dust-exposed groups also had increased release of alveolar macrophage-derived progression growth factor, but this was significantly less than macrophages from patients with idiopathic pulmonary fibrosis. Since occupational exposure was virtually identical in inorganic dust-exposed individuals with versus without respiratory impairment, the quantitative differences in the release of macrophage mediators may be due to factors in host susceptibility.

Toxicity of Fibers and Particles—report of the Workshop Held in Munich, Germany, 26–27 October 2000

“…It has been suggested that the 40% PMN level in bronchoalveolar lavage (BAL) fluid is a key level for cancer in rats. A lower, although statistically significant, increase in the percentage of PMNs has been reported in humans who were exposed to asbestos, coal, or silica and who had respiratory impairment (~4.5%, vs. 1.5% PMNs in controls) (Rom, 1991). This suggests that either the inflammation is also increased in the interstitium, or some other aspect of the inflammatory process is important, such as macrophage oxidants.…”

Understanding the Chemical Properties of Macerals and Minerals in Coal and its Potential Application for Occupational Lung Disease Prevention

“…It was shown that release of H 2 O 2 and O 2 -• is increased in AMs from coal workers with emphysema and pneumoconiosis (Rom, 1991(Rom, , 1990Wallaert et al, 1990). Plasma levels of lipid peroxidation end products, such as malondialdehyde, were higher in coal workers with early and low-grade CWP than in control subjects (Altin et al, 2004).…”

Alveolar macrophage cytokine and growth factor production in a rat model of crocidolite‐induced pulmonary inflammation and fibrosis

“…Fibronectin is chemotactic for fibroblasts and promotes fibroblast proliferation in vitro Bitterman et al, 1983). Further, increased production of fibronectin by AM has been demonstrated in interstitial lung diseases in humans Rom et al, 1987;Rom, 1991).…”