The Evaluation of IL-8 in the Serum of Pneumoconiotic patients

Ahn, Hyeong Sook; Kim, Ji Hong; Chang, Hwang Sin; Kim, Kyung Ah; Lim, Young

Abstract

Background
Many acute and chronic lung diseases including pneumoconiosis are characterized by the presence of increased numbers of activated macrophages. These macrophages generate several inflammatory cell chemoattractants, by which neutrophil migrate from vascular compartment to the alveolar space. Recruited neutrophils secrete toxic oxygen radicals or proteolytic enzymes and induce inflamatory response. Continuing inflammatory response results in alteration of the pulmonary structure and irreversible fibrosis. Recently, a polypeptide with specific neutrophil chemotactic activity, inlerleukin-8(IL-8), has been cloned and isolated from a number of cells including: monocytes, macrophages and fibroblasts. IL-1 and/or TNF-alpha preceded for the synthesis of IL-8, and we already observed high level of IL-1 and TNF- alpha in the pneumoconioses. So we hypothesized that IL-8 may be a central role in the pathogenesis of pneumoconiosis. In order to evaluate the clinical utility of IL-8 as a biomarker in the early diagnosis of pneumoconiosis, we investigated the increase of IL-8 in the pneumoconiotic patient and the correlation between IL-8 level and progression of pneumoconiosis Method: We measured IL-8 in the serum of 48 patients with pneumoconiosis and 16 persons without dust exposure history as a control group. Pneumoconiotic cases were divided into 3 groups according to ILO Classification: suspicious group(n=16), small opacity group(n=16) and large opacity group(n=16). IL-8 was measured by a sandwich enzyme immunoassay technique. All data were expressed as the mean +/- standard deviation.
Results
1) The mean value of age was higher in the small opacity and large opacity group than comparison group, but smoking history was even. Duration of dust exposure was not different among 3 pneumoconiosis groups. 2) IL-8 level was 70.50 +/-53.63 pg/ml in the suspicious group, 107.50+/-45.88 pg/ml in the small opacity group, 132.50+/-73.47 pg/ml in the large opacity group and 17.85+/- 33.85 pg/ml in the comparison group. IL-8 concentration in all pneumoconiosis group was significant higher than that in the comparison group(p<0.001). 3) IL-8 level tended to increase with the progression of pneumoconiosis. Multiple comparison test using Anova/Scheffe analysis showed a significant difference between suspicious group and large opacity group(p<0.05). 4) The level of IL-8 was correlated with the progression of pneumoconiosis(r=0.4199, p<0.05).
Conclusion
IL-8 is thought to be a good biomarker for the early diagnosis of pneumoconiosis.