Plasma polymorphonuclear elastase in patients with hyperthyroidism.

We studied plasma polymorphonuclear elastase (PMNE) levels before and during methimazole treatment in patients with hyperthyroidism. Plasma PMNE levels in patients with hyperthyroidism were significantly higher than those of normal subjects and patients with thyroid adenoma. Plasma PMNE levels in patients with Graves' disease were significantly reduced when their thyroid functions after methimazole treatment were normal, compared with the levels of the patients before treatment. In patients with hyperthyroidism there was a significant positive correlation between plasma PMNE and serum FT3, but no correlation between plasma PMNE and serum TRAb. The results suggested that PMNE was secreted from blood neutrophil in hyperthyroid state patients with Graves' disease and that it was beneficial for helping determining peripheral thyroid function.