Autoantibodies to IL-1α in sera from rapidly progressive idiopathic pulmonary fibrosis

To clarify the clinical significance of autoantibodies to interleukin-1α (IL-1α autoantibodies) in rapidly progressive idiopathic pulmonary fibrosis ( IPF ), we measured the level of IL-1α autoantibodies in serum of 11 patients on the first hospital day, when patients were admitted due to severe symptoms, and on the 21st hospital day. IL-1α autoantibodies in serum were measured using radioimmunoassay, and the limitation of this assay for IL-1α autoantibodies was 5 ng/ml. These antibodies were detected in 5 of 11 patients on the first hospital day. On the 21st hospital day, these antibodies were detected in all patients, and its level was increased compared with that on the first hospital day. IL-1α autoantibodies that appeared in patients corresponded to that of IgG. The half life of exogeneous autoantibodies was investigated following administration of autoantibody rich plasma obtained from healthy blood donors to 6 control patients (CP) and 6 progressive IPF patients. These autoantibody levels in their serum were less than 5 ng/ml before administration. Serum was obtained at the indicated time after administration of IL-1α autoantibodies and the level of these autoantibodies in serum was measured, then the half life was calculated. Half life of exogeneous IL-1α autoantibodies in progressive IPF patients was significantly shorter than that in CP (71.3±31.8 hr vs 352.0±98.3 hr, p<0.01).These findings suggested that IL-1α autoantibodies were generated in response to the inflammatory process of rapidly progressive IPF and may act as a regulatory factor for IL-1α.

データ元 : http://medical.med.tokushima-u.ac.jp/jmi/