The relationship between hyperthyroidism and the distribution of peripheral blood T, NK and B-lymphocytes in multinodular goiter.

Peripheral blood T, NK and B-cell subsets were analyzed in 18 patients with nontoxic multinodular goiter (NMG) and 11 patients with toxic multinodular goiter (TMG) in order to evaluate whether hyperthyroidism modifies the distribution of these cell populations. As a control group, 26 age and sex-matched healthy individuals were included in the study. Lymphoid subsets were analyzed with flow cytometry by double staining immunofluorescence techniques using a large panel of monoclonal antibodies. No differences were found in the absolute or relative numbers in any of the cell populations analyzed in both groups--NMG and TMG--, with the exception of a significant decrease in CD19+ cells in TMG. However, patients with multinodular goiter showed important abnormalities in the distribution of T, NK and B lymphocytes with respect to the control subjects. The pattern of abnormalities detected was characterized by a marked increase in the absolute and relative counts of activated T-lymphocytes (CD3+/HLA-DR+), cytotoxic T-cells (CD57+/CD8+) and of cells expressing NK-related antigens. None of these alterations were related to the serum levels of T3, T4 or TSH. Our results point to the existence of important abnormalities in the distribution of several lymphoid subsets in multinodular goiter, regardless of whether the subjects are euthyroid or hyperthyroid.