[Local immunity in pathology of the IgA system (IgA subclasses in the saliva of patients with A-paraproteinemia)].

: In 39 patients with A-paraproteinemia, the local immunity status was estimated according to the level of IgA subclasses in the saliva and antibody activity of secretory IgA to E. coli and S. Sonnei. Local production of normal IgA was undisturbed only in 12 patients with A-paraproteinemia, since in the saliva of those patients, there was a normal correlation of IgA subclasses and the level of antimicrobial IgA antibodies was the same as in healthy persons. The overwhelming majority of the patients with A-paraproteinemia and all the patients suffering from heavy alpha-chain disease manifested deficiency of local production of normal IgA, which consisted in the impairment of the normal correlation of IgA subclasses in the saliva and in the reduction of sIgA function. A-paraprotein was detected in many samples of the saliva using agar electrophoresis followed by immunoblotting. Secretion was shown to be mainly penetrated by the polymeric forms of A-paraprotein.