Salivary, nasal wash, and sputum IgA concentrations in atopic and nonatopic individuals

IgA and IgG levels were quantitated in parotid and nasal secretions of atopic and nonatopic children and young adults by single radial diffusion and electroimmunodifsion on the hypothesis that exocrine IgA deficiencies in atopic individuals might facilitate absorption of common “natural” inhalant allergens across respiratory tract mucosal tissues. Mean salivary and nasal wash IgA and nasal wash IgG levels were similar in both groups when expressed as per cent total protein or as IgA/ albumin ratios. Salivary IgA levels varied in individual subjects on repeated weekly, daily, or hourly analysis, but a relationship between IgA and albumin was noted in repeated samples from the same individual. Nasal wash IgA and IgG levels varied markedly among all subjects irrespective of atopic status, whether expressed in absolute values, per cent total protein, or per cent albumin. These findings suggest that a theoretical heightened mucosal absorption of inhalant allergens by atopic individuals cannot be accounted for on the basis of a local “protective” exocrine IgA deficiency per se.