Peripheral K lymphocytes in patients with subacute thyroiditis

Abstract

In a previous study, we showed that immunosuppressive acidic protein (IAP) was markedly increased in the acute phase in patients with subacute thyroiditis (SAT). In order to investigate the immunological abnormalities in SAT, peripheral K lymphocytes in SAT and hyperthyroidism were measured by the plaque-forming technique using sheep-red-blood cells as a target. The effect of the patients' serum on K-cells in normal lymphocytes was also investigated. The percentages of K-cells in 5 patients with SAT in the acute and recovery phases were 2.3 +/- 1.9 (mean +/- S.D.) and 5.3 +/- 2.2%, respectively. The former was significantly lower than the latter (p less than 0.05). Furthermore, the value in the acute phase showed a significant decrease against that of the normal controls (7.3 +/- 3.4, n = 14, p less than 0.01). The percentage of K-cells in 16 patients with hyperthyroidism was 2.8 +/- 2.2%, which was also significantly lower than that of the normal controls (p less than 0.05). The degree of inhibition of K-cells in normal lymphocytes by sera from 12 SAT in the acute and recovery phases was 69 +/- 21% and 35 +/- 22%, respectively, which was significantly higher (p less than 0.01 and p less than 0.05, respectively) than that in 12 normal sera (15 +/- 20%). Furthermore, the inhibition was markedly higher in the acute phase than in the recovery (p less than 0.01). The sera from 10 patients with hyperthyroidism also inhibited K-cells of normal lymphocytes (p less than 0.01). It was suggested that in the sera of SAT and hyperthyroidism there is some factor which inhibits K-cells.