Lymphocyte subsets in human adenoids and tonsils. Rosette formation, alpha-naphthyl acetate esterase cytochemistry, monoclonal antibodies and peanut lectin reactivity.

The distribution of mononuclear cell subsets has been studied in human adenoids, tonsils and peripheral blood (PB) by evaluating the presence of surface immunoglobulins, E-rosette formation, receptors for IgG Fc and for complement, alpha-naphthyl acetate esterase (ANAE) cytochemistry, reactivity with peanut lectin (PNA) and with monoclonal antibodies (McAb) (OK panel). Adenoids and tonsils, compared to PB, contain (1) fewer macrophages and T cells but more B cells; (2) higher proportions of ANAE negative, complement receptors and Ia-like antigens bearing T lymphocytes; (3) higher percentages of cells reacting with the McAbs OKT9 and OKT10 ("immature" lymphoid cells). In both adenoids and tonsils, clusters, formed by a central heavily ANAE stained interdigitating cell surrounded by lymphocytes with a sickle-shaped ANAE reaction, were found. Analogous clusters have been previously described in mice and human thymus. Two major hypotheses could be put forward: (1) adenoids and tonsils contain "immature" lymphoid cells undergoing education process, or (2) the above organs contain lymphocytes activated by a constant exposure to bacterial antigens or mitogens.