Molecular heterogeneity of a Graves' thyroid-infiltrating T cell population rich in CD8+ and gamma delta+ T cells

High Frequency of Thyroid Disorders in Patients Presenting With Neutropenia to an Outpatient Hematology Clinic STROBE-Compliant Article

Granulopoiesis abnormalities have been described in association with thyroid disorders (TD). However, data regarding systematic evaluation of adult neutropenia and concurrent or prior TD are scarce. To investigate the frequency of TD among patients presenting with neutropenia, and the immunophenotypic and immunologic profile of neutropenic patients with concomitant thyroidopathy. Two hundred eighteen consecutive neutropenic patients were prospectively evaluated in our outpatient Hematology Clinic, with a detailed laboratory screen, including thyroid function tests, antineutrophil antibodies, blood lymphocytes immunophenotyping, and detection of T-cell clonality by PCR. Among 218 patients with neutropenia, 95 (43.6%) had TD, 65 chronic immunologic neutropenia, 20 clonal proliferation of T-large granular lymphocytes (T-LGL), 5 autoimmune disorders, and 33 other diagnoses. TD-patients had an increased frequency of recurrent infections compared with other patients (P = 0.045). The following correlations were found: negative correlation between FT3 and absolute neutrophil count (ANC) (r² = -0.274, P = 0.007), negative correlation between TPO-Abs/TG-Abs and C4 (r² = -0.16, P = 0.045; r² = -0.266, P = 0.001), and CD4⁺ counts were inversely correlated to T4 and positively to TSH (r² = -0.274, P = 0.024; r² = 0.16, P = 0.045). In addition, TD-patients had significantly higher percentages of CD4⁺ lymphocytes (P = 0.003). Among TD-patients, 23.4% had Hashimoto thyroiditis (HT), 4.1%, Graves disease (GD), 8.2% nontoxic multinodular goiter (NTMG), 5% subclinical hypothyroidism, and 2.8% had undergone total thyroidectomy associated with nodules (TTM). Thirteen TD-patients displayed T-LGL. Patients with autoimmune thyroidopathy had an increased frequency of concomitant autoimmune manifestations (P = 0.03). Significant differences between the different thyroidopathies included: HT-patients had higher percentages of B-lymphocytes, while the opposite was evident for the TTM-subgroup (P = 0.009, 0.02); GD-patients showed an increase of the proportion of NK cells and a decrease in the percentage of TCRγδ+ lymphocytes (P = 0.001, 0.045); and NTMG-patients had significantly higher ANC (P = 0.004) compared to other thyroidopathies. Antineutrophil antibodies were found in 37.2% of TD-patients tested. Anti-TPO titers were significantly higher in patients with positive antineutrophil antibodies (P = 0.04). The frequency of TD among neutropenic patients may be higher than previously reported. The existence of antineutrophil antibodies, as well as the different distribution of lymphocyte subsets among patients with different TD, suggests both humoral and cellular mechanisms in the pathophysiology of thyroid disease-associated neutropenia.

Analysis of circulating T gamma/delta lymphocytes and CD16/56 cell populations in children and adolescents with Graves' disease

The aim of the present study was to determine the proportion of gamma/delta T-lymphocytes and CD16/CD56 (CD3- and CD3+) cells in the peripheral blood of children and adolescents with Graves' disease (GD; n = 27; mean age, 15.5 +/- 5.1 y) and nontoxic nodular goiter (NTNG; n = 25; mean age, 15.2 +/- 5.7 y), in comparison with sex- and age-matched healthy control subjects (n = 25; mean age, 15.9 +/- 2.4 y). In addition, in patients with GD, we investigated the effect of methimazole therapy on the proportion of these cells. We also looked for associations among the parameters investigated. The percentages of gamma/delta TCR+CD3+ lymphocytes and CD3+, CD16/56+CD3+, and natural killer (NK) cells were analyzed by the three-color flow cytometry using a Coulter EPICS XL cytometer. In patients with untreated GD, we observed a significant decrease in gamma/delta T (CD3+) (p < 0.002), CD16/56(CD3+) (p < 0.001), and NK (p < 0.001) cells in comparison with the healthy control subjects. After 2-6 mo of methimazole therapy, the percentages of gamma/delta TCR+CD3+ and CD16/56(CD3+) cells in peripheral blood of hyperthyroid patients returned to the normal values, whereas the percentages of NK cells normalized after 18-24 mo of therapy. These abnormalities were absent in children and adolescents with NTNG. Furthermore, there was no difference in the percentage of CD3+ lymphocytes in all of the groups. In the patients with untreated GD, we found a negative correlation between free thyroxine concentration in blood serum and the percentages of CD16/56 (CD3-) and gamma delta T cells (r = -0.5, p < 0.035; r = -0.4, p < 0.02). No such correlation was detected in patients with NTNG. We conclude that the abnormal distribution of CD16/CD56 (CD3- and CD3+) cells and gamma/delta T lymphocytes in the peripheral blood in children and adolescents with untreated GD suggests their role in the development of autoimmunity.

Infiltrating gamma/delta T-cell receptor-positive lymphocytes in Hashimoto's thyroiditis, Graves' disease and papillary thyroid cancer

In the present study we have evaluated the expression of different molecular forms of the antigen receptor (TcR) on lymphocytes derived from thyroid tissue of patients with Graves' disease, Hashimoto thyroiditis and papillary cancer both in situ by APAAP technique and on isolated lymphocytes by indirect immunofluorescence. A panel of monoclonal antibodies (mAbs) recognizing alpha/beta and gamma/delta TcR-positive subsets was used. The results showed that the large majority of T-cells in thyroid infiltrates were alpha/beta TcR+, gamma/delta TcR+ ones being very rare or nearly absent, whatever the disease (autoimmune or neoplastic). No difference between gamma/delta TcR+ T-cell subsets (V delta 1+ or V delta 2+) was observed. Thus, neither in autoimmune thyroid diseases nor in papillary cancer gamma/delta TcR+ cells are likely to be a major effector-T cell population.