Leucocyte migration inhibition with mitochondria in human autoimmune thyroid disorders.

Leucocyte migration inhibition tests (LMT) with rat and human liver mitochondria are reported in forty-nine thyroid patients and forty-seven healthy controls. Whereas normal subjects and colloid goitre cases were inactive in this test, patients with autoimmune thyroiditis and thyrotoxicosis gave positive mitochondrial reactions which paralleled the organ-specific thyroid microsomal LMT obtained in the same patients and were not species dependent. The active antigen may be in the inner membranes of the particles. As with thyroid microsomes, intense inhibition with mitochondria was seen in the hypercellular variant of Hashimoto goitre characterized serologically by low or absent thyroglobulin antibodies, and the lowest LMT values occurred in the rare cases showing poor response to thyroxine therapy. An inverse correlation was found between mitochondrial LMT and thyroglobulin antibody titres. Surprisingly, weak LMT was also found in four thyroid patients who happened to have mitochondrial antibodies in the serum in addition to the usual thyroidspecific reactivities. The mitochondrial LMT appears to be of widespread occurrence in autoimmune diseases and also develops following tissue injury. Its possible significance in relation to cellular immunity, cell destruction and the inflammatory response is discussed.