DETECTION OF CIRCULATING ANTICOMPLEMENTARY FACTORS IN CHRONIC LUNG-DISEASES

  • 1 January 1978
    • journal article
    • research article
    • Vol. 31  (2) , 237-243
Abstract
An anticomplementary technique, based upon the ability of circulating immune complexes to bind added exogenous C1 [complement component 1] after inactivation of bound endogenous C1 by heating, was used to detect anticomplementary factors in the sera of patients with bronchiectasis (chronic bronchial suppuration), chronic bronchitis and bronchial asthma. The validity of the method was determined using artificial immune complexes (rat serum albumin-anti-rat serum albumin) and the limit of detection estimated to be on the order of 200 ng complexed antigen/ml. Because heat inactivation of endogenous C1 is an essential part of the procedure, the anticomplementary activity of normal sera as a function of time of heating at 56.degree. C was examined. Wide variations in anticomplementary activity were demonstrated in these sera, which did not entirely correlate with the Ig[immunoglobulin]G levels. Comparison of the anticomplementary activity of control (n = 11) and pathological sera (n = 19) at 2 arbitrarily chosen time intervals (30 and 60 min) disclosed significant differences, which were greatest after the longer heating time. These differences were consolidated when the series was extended to include larger numbers of sera (107 pathological; 43 normal) and indicate that the frequency and/or level of anticomplementary factors in pathological sera is greater than those in controls. Qualitative changes in IgG as a result of heat aggregation or the presence of immune complexes could account for part of the anticomplementary activity of normal and pathological sera. The quantitative differences between the 2 groups indicate the presence of anticomplementary factors associated with the various disease states.