Secretory and humoral immunologic response of atopic and non‐atopic individuals to intranasally administered antigen

Abstract
Groups of twelve asymptomatic atopic and fourteen non-atopic individuals were immunized with tetanus toxoid 7.5 Lf units X 2 by means of nasal droplets. Serum and nasal secretion samples were collected on days 1, 15 and 36. Protein content of dialysed secretions was determined by the Lowry method and 1.0 mg/ml samples used for specific antibody assays by passive haemagglutination (PHA) and radioimmunosorption (RISA) employing cyanogen bromide activated Sephadex G-25. IgG, IgA, IgM, and IgD were quantitated by single radial diffusion (SRD), and IgE by the RISA technique. Mean PHA secretion titres rose significantly in both groups during the course of the study. Serum and nasal secretion RISA IgA anti-toxoid levels were higher in the non-atopic group throughout the course of immunization but both groups showed a significant increase in mean levels following immunization (P less than 0.05). Conversely nasal secretion IgE-anti-toxoid levels were significantly higher in the atopic group throughout the course of immunization although no quantitative increase in levels was noted. Total IgG, IgD, IgE, and IgM levels in serum and secretions did not rise during the course of immunization but nasal wash IgA levels rose in both groups. IgD levels were significantly higher in serum and nasal secretions of the atopic group. Our results suggest that atopic and non-atopic individuals differ quantitatively in Ig class specific antibody production following topical mucous membrane immunization.