DETECTION OF TRANSFORMING GROWTH-FACTOR-BETA IN SPUTUM FROM PATIENTS WITH BRONCHIAL-ASTHMA BY EOSINOPHIL SURVIVAL ASSAY AND ENZYME-LINKED-IMMUNOSORBENT-ASSAY

Background We have shown that interleukin-5 (IL-5) and granulocyte-mac rophage colony-stimulating factor (GM-CSF) are present in sputum from patients experiencing acute asthma attacks, by eosinophil survival ass ay. The viability of guinea-pig eosinophils was significantly increase d in the presence of such sputum extracts after 3 days' culture, and i t was inhibited by the addition of anti-IL-5 and anti-GM-CSF antibodie s. However, the contribution of IL-5 to the increase in eosinophil via bility was less than expected from the values of IL-5 measured by enzy me-linked immuno-sorbent assay (ELISA). Therefore, we speculated that something in sputum inhibited the function of IL-5. Objective Transfor ming growth factor-beta (TGF-beta) was the only cytokine we tested tha t inhibited the prolongation of survival of guinea-pig eosinophils ind uced by IL-5. The objective of this study is to detect TGF-beta in the same sputum. Methods Guinea-pig eosinophils were cultured with or wit hout anti-TGF-beta antibody in the presence of sputum extracts, and th e eosinophil viability was counted after 3 days. Measurement of TGF-be ta(1) in sputum was performed by ELISA. Results Eosinophil viabilities with and without anti-TGF-beta antibody were 79.7+/-2.9% and 69.0+/-2 .7%, respectively, and the difference between them was statistically s ignificant (P < 0.05, n = 9). The concentration of TGF-beta(1) in the sputum was 21.7+/-3.3 ng/mL (n = 9). Conclusion These observations sug gest that TGF-beta is present in sputum from patients with bronchial a sthma.