ExtractPeripheral blood leukocytes from eleven normal individuals and five boys with Bruton-type agammaglobulinemia were cultured in vitro with Candida albicans antigen. The lymphocyte response in vitro was measured by morphologic transformation into blast cells and by incorporation of tritiated thymidine into DNA. Delayed hypersensitivity was measured by the standard skin test, and circulating antibody titers were estimated by agglutination of heat-killed Candida.A response to Candida antigen was demonstrated in cultures of lymphocytes taken from six normal individuals (table I) and from four patients with agammaglobulinemia (table II). The in vitro lymphocyte response correlated with the results of skin tests but not with titers of circulating antibody.The results with agammaglobulinemic lymphocytes support the view that the in vitro lymphocyte response is a correlate of delayed hypersensitivity.
SpeculationBoth humoral antibody formation and delayed hypersensitivity reactions originate in lymphoid tissues. From these tissues, small lymphocytes circulate to peripheral blood. Investigations of peripheral blood lymphocytes from patients with Bruton-type agammaglobulinemia are of interest because these patients have normal delayed hypersensitivity reactions despite an inability to synthesize more than trace amounts of circulating antibody. As a result, these patients may be considered a source of lymphocytes with immunologic capacity limited almost entirely to delayed hypersensitivity.