Abstract
We present 3 cases of broncho-pulmonary diseases, lung cancer, bronchial asthma and pulmonary abscess, which revealed selectively deficient serum IgA. Serum levels of IgA in these cases were definitely below normal. IgA levels in bronchial washing, sputum and saliva decreased in one case, but there were no abnormalities in IgA levels in external secretions in two other cases. In the bronchial asthma, deficiency of IgA might be induced by glucocorticosteroid or gold salt treatment.
The precise mechanisms of IgA deficiency have not yet been determined and it may be that some immunological abnormalities exist in these cases. Several mechanisms of IgA deficiency were discussed.
