[Circulating monocyte (macrophage)-specific antibodies in patients with autoimmune thyroid diseases]

We investigated the presence of circulating monocyte-specific antibodies (monocytotoxic activities) by cytotoxicity tests and also the relationships between these monocytotoxic activities and the clinical data in autoimmune thyroid diseases. Subjects of this investigation include 16 patients with Graves' disease, 20 patients with Hashimoto's thyroiditis and 10 normal controls. To obtain monocyte-rich population, peripheral blood mononuclear cells of type 0 healthy donor were incubated on culture dishes for 12 hours and dish adherent cells were separated by pipetting. These monocyte-rich population were incubated with sample sera which were previously absorbed by lymphocytes of many different kinds of HLA types to eliminate anti-lymphocyte antibodies, and thereafter cytotoxicity tests were performed by adding rabbit complements. The monocytotoxic activities were expressed by %cytotoxicities and the value of %cytotoxicity over 3.9% (mean + 4SD of %cytotoxicities of normal controls) was considered to be positive in monocytotoxic activity. The results indicate that; 1) 8 patients (50%) of Graves' disease and 10 patients (50%) of Hashimoto's thyroiditis had positive values of monocytotoxic activity. 2) These positive values of monocytotoxic activity were markedly decreased after absorption of sample sera by monocytes, and these patients who had positive values of monocytotoxic activities to allogenic monocytes also had positive values of monocytotoxic activities to autologous monocytes. 3) Patients who had positive monocytotoxic activities also had high levels of TSH receptor antibody (TRAb) and anti-microsomal antibody, besides, monocytotoxic activity was significantly correlated with levels of TRAb in Graves' disease.(ABSTRACT TRUNCATED AT 250 WORDS)