Significance of the interleukin-1 receptor antagonist/interleukin-1 beta ratio as a prognostic factor in patients with pulmonary sarcoidosis

Background: Various factors such as serum angiotensin-converting enzyme (sA CE) activity, bronchoalveolar lavage (BAL) fluid lymphocyte percent, CD4/CD 8 ratio, and shadows on chest radiograph have been identified as indexes of disease activity in patients with sarcoidosis. However, it remains to be c onfirmed whether these factors can predict clinical outcomes. Objective: To examine whether the interleukin-1 receptor antagonist (IL-1 ra >/ IL-1 bet a ratio can predict the clinical course, we prospec tively followed the cli nical courses of 30 patients with pulmonary sarcoidosis 4 years after measu rement of immunoreactive amounts of IL-1ra or IL-1 beta in the culture supe rnatants obtained from BAL fluid macrophages. Methods: Immunoreactive amoun ts of IL-1ra or IL-1 beta were measured using ELISA, Changes in pulmonary f unction, sACE activity, and shadows on chest radiographs during observation periods were evaluated as markers of changes in disease activity. Results: We found that the patients whose shadows on chest radiographs showed impro vement had a higher molar IL-1ra/ IL-1 beta ratio than the patients whose s hadows persistently remained 4 years after BAL examination (p < 0.05). The molar ratio was found to be positively correlated with improvement of perce nt vital capacity (p < 0.05) and negatively correlated with the ratio of sA CE activity at the time of the last observation to sACE activity at the tim e of BAL (sACE(LAST)/sACE(BAL), p < 0.01) The SACE(LAST)/SACE(BAL) ratio wa s significantly lower in patients whose shadows on chest radiographs decrea sed than in those whose shadows remained unchanged (p ( 0.005). Conclusion: The IL-1ra/IL-1 beta ratio in the BAL fluid macrophage culture supernatant s in patients with pulmonary sarcoidosis could be a useful marker in predic ting the persistence of granulomatous lesions (chronicity). Copyright(C)200 0S.KargerAG.Basel.