Paracoccidioidomycosis in the region of Botucatu (state of São Paulo, Brazil). Evaluation of serum thyroxine (T4) and triiodothyronine (T3) levels and of the response to thyrotropin releasing hormone (TRH)

T4, T3 and TSH serum levels were measured in 25 patients with paracoccidioidomycosis. Thyroid T3 reserves were measured on the basis of the increase in T3 (delta T3) 2 h after intravenous injection of 200 micrograms TRH, and pituitary TSH reserves were measured on the basis of TSH increase (delta TSH) 20 min after the same injection. Twenty healthy volunteers with no history of thyroid disease were used as controls. When the two groups were compared, the following results were obtained: (a) there was no significant difference in mean T4, T3, delta TSH between groups; (b) reduced T3 levels were detected more frequently in patients with paracoccidioidomycosis, especially among those with the acute form of the disease or with the severely disseminated chronic form. The results suggest the occurrence of a reduction in peripheral conversion of T4 to T3, but do not indicate the occurrence of hypothyroidism in any of its forms (thyroid, pituitary or hypothalamic).

Immunological disturbances in toxic multinodular goitre and active Graves' disease

Cell-mediated and humoral immunity were studied in seventeen patients with toxic multinodular goitre, ten with active Graves' disease and fourteen healthy controls. The study included determination of sheep erythrocyte and complement rosette-forming cells in the peripheral blood, immunoglobulin levels, titres of microsomal antibodies and migration inhibition test using thyroid extract and phytohaemagglutinin. When compared with controls the patients showed a positive response to thyroid antigen in the leucocyte migration inhibition test. Microsomal antibodies were detected in seven out of ten active Graves' disease patients against two out of seventeen of those with toxic multinodular goitre. Significantly increased IgG and IgA and deceased IgM levels were found only in the toxic multinodular group. These data provide further evidence for immunological disturbances in toxic multinodular goitre.

Humoral and cell-mediated immunity in large non-toxic multinodular goitre

Humoral and cell-mediated immunity was investigated in fourteen patients with non-toxic multinodular goitre and ten healthy controls by in vitro methods. These included determination of sheep erythrocyte and complement rosette-forming cells in the peripheral blood, immunoglobulin levels, titres of thyroglobulin and microsomal antibodies and migration inhibition test using thyroid extract and phytohemagglutinin. When compared with controls the patients showed high IgA levels and positive response to thyroid antigen in the leucocyte migration inhibition test. There was no correlation between the leucocyte migration results and the presence of auto-antibodies. These findings indicate a possible role of cell-mediated immunity in non-toxic multinodular goitre.

3,3',5'-triiodothyronine, thyroxine, triiodothyronine, and thyrotropin levels in maternal and cord blood sera from endemic goiter regions of Brazil

T4, T3, rT3, and TSH were measured in cord blood of infants born in mild to severe endemic goiter areas and nonendemic urban areas in South and North America. A significantly high rT3 concentration was found in newborns living in the urban area of South America as compared to a Canadian newborn population. There were no differences among the various thyroid parameters in the groups of newborns studied. Blood from goitrous mothers showed significantly higher concentrations of T3 and TSH than nongoitrous mothers. However, these changes did not affect the concentrations of thyroid hormones, rT3, or TSH in the fetal circulation.