The Influence of Immunosuppressive Acidic Protein on the Activity of Peripheral K-Lymphocytes in Subacute Thyroiditis

We previously reported that immunosuppressive acidic protein (IAP), an α1-acid glycoprotein, is increased during the acute phase of subacute thyroiditis (SAT). In this study we measured the percentage and absolute number of peripheral K-cells using a plaque-forming cell technique to investigate immunological abnormalities associated with SAT. Additionally, we investigated the relationship between IAP and peripheral K-cell activity. In normal controls, a sex-related difference in the percentage of K-cells among total lymphocytes was present; the percentage was significantly lower in women (mean ± SD, 5.0 ± 2.0%; n = 12; P < 0.01) than in men (8.4 ± 2.9%; n = 13). However, there was no difference (0.153 ± 0.073 × 109/L in five females; 0.173 ± 0.054 × 109/L in seven males) in the absolute number of peripheral K-cells. During the acute phase of SAT, the percentage (2.4 ± 1.9% in 16 females; 2.7 ± 1.0% in 3 males) and absolute number (0.058 ± 0.048 × 109/L in 11 females) of K-cells were significantly lower th...