Specific antibodies bound to secretory IgA in the sera of patients with intestinal infections]

Specific IgA and sIgA antibodies were studied in the sera of patients suffering from various intestinal diseases (dysentery, salmonellosis, typhoid fever, chronic typhoid carrier state) and in the sera of healthy persons immunized by parenteral route with typhoid alcohol vaccine. The nature of antibodies was identified in Coombs' test, using monospecific antisera to alpha-chain and to the secretory component. IgA and sIgA antibodies were revealed most frequently in the sera of dysentery patients and of chronic typhoid carriers. No sIgA antibodies were found in the sera of subcutaneously immunized persons. The presence of specific sIgA antibodies in the serum reflects the participation of local immune mechanisms in the formation of systemic immunity in the intestinal infections.