Lymphoid tissues and the immune system in mastocytosis.

The association of mast cells and lymphoid tissues may reflect either regional overproduction of growth factors for mast cells or a predisposition for mast cells at certain sites within the body, particularly the liver, lymph nodes, and spleen. The significant increase in mast cell number associated with mastocytosis is not sufficient to generate a change in either T-cell or B-cell functions, as evaluated by analyzing cytokine phenotype or immunoglobulin production, respectively, nor to expose these patients to infections or allergic diseases. Mast cells in mastocytosis cannot be said with certainty to be "normal" in all respects, however, and the failure to identify an effect of mast cells on either B-cell Ig production or T-cell cytokine profiles cannot be taken as absolute evidence that mast cell products have no influence on lymphocyte function, particularly at the local tissue level.