Combined immunodeficiency disease associated with adenosine deaminase deficiency. Report on a workshop held in Albany, New York, October 1, 1973

Restoration of in-vitro lymphocyte responses with exogenous adenosine deaminase in a patient with severe combined immunodeficiency

Deficiency of adenosine deaminase (A.D.A.) occurs in an autosomal recessive form of severe combined immunodeficiency (S.C.I.D.). The role of this enzyme deficiency in the pathogenesis of the immune defects is not clear. A patient with A.D.A. S.C.I.D., studied during the first six weeks of life, was found to have B and T lymphocytes as well as 25% of normal lymphocyte responses to mitogens. This patient subsequently became severely lymphopenic with loss of mitogen responsiveness. Addition of calf-intestinal A.D.A. or human-erythrocyte A.D.A. to cultures of this patient's lymphocytes restored their ability to proliferate when stimulated with mitogens. These data indicate that A.D.A. deficiency is causally related to the cellular immune defects observed in A.D.A. S.C.I.D. and suggests a possible role for enzyme replacement in the therapy of this disorder.

Demonstration of an intrathymic defect in a case of severe combined immunodeficiency disease

An in vitro system has been developed to elucidate the nature of the cellular defect in primary immunodeficiency diseases. Incubation, on human thymic epithelial monolayer cultures, of peripheral blood lymphocytes and bone-marrow cells from a child with documented severe combined immunodeficiency disease resulted in the appearance of a population of cells that formed rosettes with sheep erythrocytes. The same cell preparation permitted the synthesis of antigen-specific, complement-dependent antibodies after in vitro education, as demonstrated in a plaque assay system. In addition, thymic tissue from the same child gave morphologic and functional evidence of maturation when cultured in vitro. The experimental results suggest that in this case, lymphoid precursor cells were present in the bone marrow but failed to differentiate to functional maturity due to a defect in maturation of thymic tissue.

[Incomplete, combined hereditary immunodeficiency with generalized tuberculosis after BCG-vaccination from bacille Calmette Guérin (author's transl)]

A case of hereditary incomplete, combined immunodeficiency is reported. The patient, a 20-week-old boy, suffered from severe, generalized tuberculosis after BCG-vaccination. A conspicuous discrepancy was found between the normal number of lymphocytes in the peripheral blood and the severe morphological changes in the organs of the lymphoreticular system (deficient development of thymic structures; absence of lymphocytes in the thymus and the thymus-dependent areas of the periphery as well as in the bursa-dependent structures). A partial primary defect of the stem cells and a secondary insufficiency of the functions with incomplete differentiation due to an insufficiency of the primary lymphatic organs are discussed as possible causative factors. The inability to develop epitheloid cells in connection with the tuberculous infection is interpreted in part as a sequence of a T-cell insufficiency.

Inhibition of mitogen mediated lymphocyte blastogenesis by adenosine

The effect of adenosine on the proliferative response of human peripheral circulating lymphocytes to stimulation by concanavalin A, phytohemagglutinin and pokeweed mitogen was evaluated. Increasing concentrations of adenosine substantially inhibited mitogen mediated lymphocyte blastogenesis. Erythro-9(2-hydroxyl-3-nonyl) adenine. HCl enhanced the inhibitory effect of adenosine. Inosine, the deamination product of adenosine, had an inhibitory effect which was less than that of adenosine. Inhibition by adenosine may be relevant to the normal regulation of immune function and may account in part for the pathophysiological relationship between severe combined immunodeficiency disease and adenosine deaminase deficiency.