Increased circulating T alpha lymphocyte population in bronchogenic and colonic carcinoma.

The proportion of T lymphocytes bearing membrane receptors for IgA (T alpha cells) was markedly increased in the peripheral blood of patients suffering from cancers of the colon and bronchus compared to an age-matched normal population and to age-matched control patients being treated for non-malignant chronic inflammatory conditions of the intestine and lung. By contrast, the percentage of the T lymphocyte population having Fc-IgG receptors (T gamma cells) and Fc-IgM receptors (T mu cells) in mucosal malignancy was similar to that found in the two control populations. It is suggested that the increased percentage of T alpha cells found in colonic and bronchogenic carcinoma patients may reflect an as yet unknown regulatory function for this subset.