Parameters of respiratory burst and arachidonic acid metabolism in polymorphonuclear granulocytes from patients with various thyroid diseases

Abstract

The oxidative processes (oxygen consumption, Superoxid anion generation, arachidonic acid cascade) of human polymorphonuclear granulocytes (PMNs) obtained from patients suffering from thyroid disorders of autoimmune origin (Graves' disease and Hashimoto's thyroiditis), and non autoimmune origin (toxic adenoma ) were investigated. All Graves' and toxic adenoma patients were hyper thyroid. Hashimoto's thyroiditis patients were euthyroid. Healthy age and sex matched volunteers served as controls. The results are as follows: 1) In PMNs from both hyperthyroid groups (Graves' disease and toxic adenoma), independently from the autoimmune origin of the disease, a significantly increased Antimycin A sensitive mitochondrial oxygen consumption and a slightly increased superoxide anion generation were detected. 2) In both autoimmune thyroid disease groups (Graves' disease and Hashimoto's thyroiditis) — depending on the functional state of the thyroid gland — a significantly altered intracellular killing activity was measured. 3) An increased arachidonic acid cascade — triggered by opsonized zymozan (OZ) — was detected in both autoimmune thyroid diseases. The increased arachidonic acid cascade was sensitive to phospholipase A₂ inhibiting Mepacrin treatment. 4) The PMNs from both autoimmune thyroid diseases produced large amount of leukotriens (LTs) — LTC₄ and LTB₄ — after stimulation through their Fc receptors but the synthesis of prostagalandins (PGs) has not changed. There are no data indicating local, specific effects of circulating leukotriens in the thyroid gland itself, but based on authors' data, their general, regulating role on both the endocrine — as well as on the immune system -seems to be plausible.