Lack of systemic anaphylaxis and aeroallergen-induced airway plasma extravasation in allergic immunoglobulin-deficient mice

Background: In Ig-deficient mice allergen challenge-induced pulmonary late phase inflammation is at least as pronounced as in wild-type animals. This study investigates immediate hypersensitivity responses in these mice. Meth ods: To examine the acute plasma extravasation response in airway tissue, i mmunized Ig-deficient and wild-type mice and sham-immunized wild-type contr ols were subjected to 15 min ovalbumin aerosol challenge. I-125-albumin was injected (i.v.) 1 min prior to challenge. Immediately after challenge I-13 1-albumin was injected and the experiment was terminated. Plasma and trache a were analyzed for I-125 and I-131, and the amount of extravasated plasma in the trachea was calculated. To study the development of systemic anaphyl axis immunized Ig-deficient and wild-type animals recieved intravenous alle rgen challenge followed by determination of mast cell responses and plasma histamine levels. Results:Allergen aerosol-exposed immunized wild-type mice exhibited marked plasma extravasation in the trachea (pd0.01 vs. wild-type controls), but in the corresponding Ig-deficient mice there was no increas ed extravasation. Immunized Ig-deficient mice receiving intravenous allerge n challenge were resistant to anaphylactic shock. By contrast, the wild-typ e animals developed systemic anaphylaxis, accompanied by plasma extravasati on, mast cell degranulation, elevated plasma histamine and rapid death. Con clusion:The present data are evidence that immunoglobulins are crucial for the development of immediate (type 1) responses. These findings together wi th our previous observations on late-phase pulmonary responses suggest that immediate hypersensitivity processes are unimportant for development of th e late phase inflammation in the respiratory tract of mice.