[Evaluation of the usefulness of using western immunoblotting for testing humoral immune response to Mycoplasma pneumoniae antigens during natural infection in humans].

One hundred and twenty serum specimens from 80 subject were tested for the presence of IgA, IgG and Ig M antibodies to polypeptides of M. pneumoniae with a molecular weight of 170 (P1 protein), 120, 110, 89, 66, 55, 43, 38, 33 KDa in an immunoblot assay. For most of the polypeptides, there was an increase in the frequency of band detection when the CF titres were higher. Sera with the diagnostically significant titre in the CF test (titre > or = 60) were positive for anti - P1 IgA antibodies in 68.3%, for IgG antibodies in 87.8% and for Ig M antibodies in 70%. Particular attention in this study was given to the blotting pattern of paired serum specimens from 17 patients who exhibited a four-fold or greater rise of antibody titre by the CF test. In acute phase sera, collected in the first week of disease, the frequency of the occurrence of antibodies against P protein did not exceed 18%. Two - three weeks later, Ig A antibodies were detectable in 82.4%, Ig M antibodies in 76.5% and Ig G antibodies in all convalescent phase sera. The study demonstrated that immunoblot assay which is characterized by very high sensitivity and specificity may be successfully used in examination of humoral response to M. pneumoniae antigens.