Systemic and local immunity in juvenile autoimmune thyroiditis

Abstract

The relative and absolute numbers of circulating and thyroidal T and B lymphocytes were studied in 16 euthyroid patients with juvenile autoimmune thyroiditis (JAIT). The same cell populations were tested for cell-mediated immunity (CMI) to thyroid antigen in the leukocyte migration test (LMT). The diagnostic criteria of JAIT were a firm goitre, circulating thyroid antibodies and lymphocytic infiltration of the thyroid gland. The relative and absolute numbers of circulating T and B cells were normal (73 and 19%, respectively). Of the thyroidal lymphocytes 49% were B and 42% T cells. In LMT, half of the patients were positive when tested with circulating leukocytes, but negative when tested with thyroidal cells. Thus, in JAIT, antigen-sensitive thyroidal T cells are absent or inactive.