Autoantibody In Emphysema Induced By Smoke And An Model Of Emphysema By Anti-elastin Immunization In Guinea Pig

Objective:To ascertain if autoimmunity is involved in the pathogenesis of emphysema, and the possible role of elastin as one of the autoantigens. To study whether the immunization induced by hypodermic injection of human elastin fragments can result in emphysema in guinea pigs.Methords:Guinea pigs were randomly divided into 3 groups, with two model groups treated separately by cigarette inhalation or hypodermic injection with compound of human elastin fragments and adjuvant, and the control group given no treatment。All those animals were bred for 12 weeks. Lung tissue slices were stained by hematoxylin-eosin, and the pathologic changes of lungs and alveolar radii were determined. IgG deposition in lung tissues was detected by immunohistochemistry. Anti-elastin IgG antibody in serum were detected by enzyme-linked immunosorbent assay. The data were statistically analyzed.Results:1. The lungs of smoking group and elastin-immunized group showed enlarged lung alveolar airspaces with increased alveolar radii when compared with the control group(P<0.001, P<0.001), while the increase of alveolar radii in smoking group was greater than that in elastin-immunized group (P< 0.01);2. IgG deposition in lungs was detected in seven of ten (70%) animals in smoking group and five of eight (62.5%) in elastin-immunized group, but in none of the normal lungs, and smoking group showed greater stain intensity than elastin-immunized ones (P<0.01);3. Anti-elastin IgG antibodies in serum were detected in three groups, with higher level in two model groups when compared with the control (P<0.05, P<0.05), but there was no significant difference between two models (P>0.05)Conclusion:1. Autoantibodies with avidity against lungs are prevalent in guinea pigs with emphysema induced by cigarette exposure, and autoimmunity may be involved in the pathopoiesis of emphysema. Elastin fragment may be one of the autoantigens.2. Human elastin fragments hypodermic injection can induce anti-elastin immunization and anti-elastin antibody production, and result in emphysema in guinea pigs.