RESUMEN
Recent reports suggested dendritic cells (DCs) to be important players in the pathogenesis of autoimmune thyroid processes in humans. However, there are virtually no data addressing the influence of thyroid autoaggression-associated disturbances of thyrometabolic conditions on DCs biology. The aim of the study was to evaluate the influence of L-thyroxine supplementation on conventional and plasmacytoid peripheral blood DCs subtypes in patients with hypothyroidism due to Hashimoto's thyroiditis (HT). Eighteen patients with newly diagnosed hypothyroidism due to HT were included into the study. All patients received L-thyroxine treatment with doses adjusted to reach euthyroidism. Peripheral blood DC subtypes structure and immunoregulatory phenotype were analyzed by flow cytometry in the same patient prospectively at two time points: (i) before and (ii) 3 months after beginning of L-thyroxine treatment (hypothyroidism vs. euthyroidism, respectively). Percentage of plasmacytoid DCs in peripheral blood mononuclear cells fraction was significantly decreased in the course of L-thyroxine treatment (0.27 ± 0.19 vs. 0.11 ± 0.08; p < 0.05), whereas we did not observe any changes in the number of conventional DCs. However, the phenotypic analysis showed a significant increase of conventional DCs expressing CD86 and CD91 (64.25 ± 21.6% vs. 86.3 ± 11%; p < 0.05 and 30.75 ± 11.66% vs. 44.5 ± 13.3%; p < 0.05; respectively) in euthyroid patients. Standard L-thyroxine supplementation in HT patients exerted significant immunoregulatory effects, associated with quantitative and phenotypic changes of peripheral blood DC subpopulations.
Asunto(s)
Células Dendríticas/efectos de los fármacos , Enfermedad de Hashimoto/tratamiento farmacológico , Hipotiroidismo/tratamiento farmacológico , Tiroxina/farmacología , Adulto , Antígeno B7-2/genética , Antígeno B7-2/metabolismo , Células Dendríticas/metabolismo , Enfermedad de Hashimoto/complicaciones , Humanos , Hipotiroidismo/etiología , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/genética , Proteína 1 Relacionada con Receptor de Lipoproteína de Baja Densidad/metabolismo , Persona de Mediana Edad , Estudios Prospectivos , Tiroxina/uso terapéuticoRESUMEN
Dendritic cells (DCs), considered as one of the crucial immune regulatory populations, are implicated in the immune pathology of various disorders. Also in the thyroid gland, DCs were shown to be involved in early and chronic phases of various types of autoimmunity - including Hashimoto's thyroiditis and Graves' disease. In thyroid malignant processes, DCs are suggested as an important element of both tumour defence and tumour immune evasion mechanisms. Recent findings emphasize a crucial role of interactions between particular DC subsets and other regulatory cell populations (e.g. FoxP3+ regulatory T cells) in thyroid pathology. Additionally, an increasing attention has been paid to the control of DC function by thyrometabolic conditions.