CELLULAR SITES OF IMMUNOGLOBULINS

The proportions of IgG‐, IgA‐, IgM‐ and their k and Λ light polypeptide chain‐containing cells were determined in non‐hypertrophied relatively normal and in recurrently inflamed hypertrophied tonsils by staining with two contrast‐labelled fluorochromes and directly counting such cells in a single tissue section. Their defence mechanisms were also discussed. Human palatine tonsils, like the lamina propria of the gastrointestinal tract, are very rich in plasma cells containing immunoglobulins. In the gastrointestinal tract such cells predominantly contain IgA and those IgA cells were counted above 80% of the population of all immunoglobulin containing cells. In the present study of palatine tonsils, the IgA‐con‐taining cells were fewer than in the lamina propria of the gastrointestinal tract but much more than in the spleen or lymph nodes. Fluorescent immunoglobulin‐containing cells under the submucosa of crypts and superficial portions of lymphoid tissues of non‐hypertrophied tonsils were fewer than 10 per high power field (×400) and relatively rich in IgA. In recurrently inflamed hypertrophied tonsils such immuno‐globulin‐containing cells increased to 20 or more cells per high power field (×400) and migrating IgG‐ and IgA‐ containing cells were present among the non‐reactive epithelial cells. In the areas of severe inflammation with superficial exudate, IgG‐ containing cells predominated, and there were no IgM cells.