Thymic Alymphoplasia With Immunoglobulin Synthesis

THE DEMONSTRATION that immunoglobulin production was normal or minimally impaired in neonatally thymectomized animals^1-3 has led to the speculation that man may have two distinct types of peripheral lymphoid tissue, each dependent upon a different primordial gut-associated lymphoid tissue ("central lymphoid tissue") for its development.⁴ The peripheral lymphoid tissue considered dependent on the thymus as the central lymphoid tissue ("thymic-dependent tissue") is the small lymphocyte which has an important role in delayed hypersensitivity and homograft rejection.^3,5,6 The other peripheral lymphoid tissue consists of the large pyroninophilic lymphocytes and plasma cells which produce the immunoglobulins⁷ and is referred to as the immunoglobulin-producing system. The central lymphoid tissue of the immunoglobulin-producing system, has been definitely identified only in the chicken where the bursa of Fabricius, a hindgut lymphoid organ, is this central lymphoid tissue.^3,8

These considerations have led to the suggestion that some of the immune-deficiency diseases