Cytofluorometric analysis of lymphocyte subsets in thyroid aspirates from patients with autonomously functioning nodules

Different cytokine mRNA profiles in Graves' disease, Hashimoto's thyroiditis, and nonautoimmune thyroid disorders determined by quantitative reverse transcriptase polymerase chain reaction (RT-PCR)

Intrathyroidal lymphocytes are a source of cytokines thought to stimulate or maintain the immune process within the thyroid in Graves' disease (GD) and Hashimoto's thyroiditis (HT). Quantitative assessment of the cytokine profile may provide important clues as to the Th1/Th2 balance prevailing in these diseases. We analyzed cytokine mRNA expression levels in thyroid tissue samples from 13 patients with GD, 2 with HT, 5 with nontoxic multinodular goiter (NTG), and 4 with thyroid autonomy (nodular = TAnod and perinodular = TAperi tissue) using multispecific competitor fragments with primer sequences for IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, IFN-gamma, CD25, and CD3 delta-chain mRNA. Patients with GD were subdivided into two groups according to their serum levels of antibodies to thyroperoxidase (anti-TPO; GDhigh > 4000 U/mL, GDlow < or = 200 U/mL). These levels correlated positively with the CD3 delta-chain mRNA levels (r = 0.83) and with the T cell infiltration (r = 0.71) as determined by immunohistochemistry. Patients with GDhigh demonstrated 2- to 4-fold higher IL-4 mRNA levels (as compared to all other investigated groups) and significantly higher IL-10 mRNA levels as compared to HT, GDlow, and TAnod patients. Patients with GDhigh also had significantly higher levels of IFN-gamma, IL-1 beta, IL-8, and CD25 mRNA as compared to GDlow. The highest IFN-gamma, IL-2, and CD25 mRNA levels were found in HT. The lowest mRNA levels of all the investigated groups were detected in TAnod. No significant differences in IL-6 and IL-8 mRNA levels were found between most of the patient groups. In summary, patients with GDhigh showed a shift to a more Th2-driven cytokine pattern. In contrast, the increase mRNA levels of Th1-related cytokines found in HT indicate predominantly T cell-mediated cytotoxic processes.

[Anti-thyroid peroxidase in non-neoplastic thyroid pathology]

Anti-thyroid peroxidase antibodies were prospectively assayed and compared with anti-microsome and anti-thyroglobulin antibodies in 203 patients (188 women, 15 men; mean age 42 +/- 14 years). These patients consulted for hyperthyroidism (n = 42, including 18 with Graves' disease), fumary hypothyroidism (n = 50, including 20 at the diagnosis stage), euthyroid diffuse or nodular goitre (n = 81) or benign euthyroid nodule (n = 14). Sixteen patients examined for fatigue, gynecomastia, menstrual disorders or overweight had normal thyroid function. Anti-thyroid peroxidase, anti-microsome and anti-thyroglobulin antibodies were assayed by radioimmunology or indirect immunofluorescence. Anti-thyroid peroxidase antibodies were most frequently present in patients with autoimmune thyroid diseases, such as Graves' disease (72%) or primary hypothyroidism (70%), and correlated with anti-microsome antibody levels (r = 0.87; p less than 0.001). Anti-thyroid peroxidase antibodies were absent in patients with benign euthyroid nodule; they were present in 22% of patients with euthyroid goitre and in 12% of control patients; their level decreased during replacement therapy for hypothyroidism. It is concluded that radioimmunological assays of anti-thyroid peroxidase antibodies should replace anti-microsome and anti-thyroglobulin antibodies in thyroid evaluation.