Evidence for acute release of thyroid peroxidase during subtotal thyroidectomy.

An immediate reduction of thyroglobulin autoantibodies during subtotal thyroidectomy of thyroglobulin antibody positive patients has previously been shown to indicate an acute release of thyroglobulin into the circulation peroperatively. The aim of the present study was to investigate whether thyroid peroxidase was also released by measuring anti-thyroid peroxidase antibodies by a quantitative and antigen specific method both pre- and postoperatively in patients positive for anti-thyroid peroxidase antibodies. Twelve anti-thyroid peroxidase positive patients (11 females, 1 male) referred for surgery of toxic goitre were studied. Median age was 43 years (range 24-64) and median goitre size 86 g (25-165). All patients had been pretreated with antithyroid drugs and were euthyroid at the time of operation. Anti-thyroid peroxidase was measured before operation, 1-8 h, 10 days, 1-3 months, and 12 months postoperatively by a commercial method (DYNO-test, Henning, Berlin). The median anti-thyroid peroxidase level before operation was 1048 kU/l (range 68-10 517 kU/l) and fell during operation to 0.63 (range 0.37-1.28) (p less than 0.01) of initial concentration without further decrease during the next 1-8 h. The comparative decrease in thyroglobulin antibodies was 0.19 (0-0.88). The anti-thyroid peroxidase level was increasing after 10 days, but did not reach initial level until between 3 and 12 months after surgery. However, in 3 of 10 patients anti-thyroid peroxidase had disappeared after 12 months, all of whom had low levels before operation, whereas anti-thyroid peroxidase was 2-4 times higher than preoperatively in 3 other patients.(ABSTRACT TRUNCATED AT 250 WORDS)