Abstract
A significant reduction of the percentage of J‐chain‐positive intra‐ and extra‐follicular IgA immunocytes was found in inflamed palatine tonsils. There was a tendency to similar alterations in hypertrophied adenoids. Tonsillar disease apparently enhances local maturation of the B‐cell system, perhaps on the basis of intensified proliferation of memory clones. Alternatively, there may be a disease‐associated defect in the mechanism(s) that normally induces switchover to the IgA isotype early in clonal development. It is speculated that, by decreasing the J‐chain expression during local B‐cell differentiation, tonsillar disease may jeopardize the potential of the tonsils as a putative precursor source for the secretory immune system of the upper aero‐digestive tract.