2021. gadā aizstāvētie promocijas darbi un kopsavilkumi

Permanent URI for this collection

http://hdl.handle.net/123456789/4164

Browse

Browsing 2021. gadā aizstāvētie promocijas darbi un kopsavilkumi by Author "Groma, Valērija"

Now showing 1 - 3 of 3
  • No Thumbnail Available
    Item
    Thyroid Autoimmunity: Exploring the Role of Th17-associated Cytokines and Pathomorphological Mechanisms Involved in the Pathogenesis of Hashimoto’s Thyroiditis and Graves’ Disease. Doctoral Thesis
    (Rīga Stradiņš University, 2021) Zaķe, Tatjana; Groma, Valērija; Konrāde, Ilze
    The prevalence and incidence of autoimmune thyroid diseases (AITD), presenting as Graves’ disease (GD) or Hashimoto’s thyroiditis (HT), has increased significantly in recent decades. It is crucial to identify immunological and pathomorphological factors involved in thyroid autoimmunity. Classically, HT has long been considered as a T helper (Th)1-mediated disease, while a Th2-driven autoimmune response is dominant for GD. Recently, Th17 cells have been established to play a role in the pathogenesis of AITD, however, their contribution to the initiation and progression of AITD remains unclear. Furthermore, selenium deficiency can impair the differentiation of Th cells, leading to dysfunction of cellular and humoral response. The aim of this thesis was to explore the role of Th17 cells in the pathogenesis of HT and GD by the use of different morphology methods and xMAP technology, and correlating these data with the selenium status. The initial study included 29 adult patients with AITD who underwent thyroidectomy, whereas subsequent clinical research project involved 52 patients with newly diagnosed, treatment-naïve AITD, as well as 26 healthy subjects served as controls. The plasma levels of Th17-associated cytokines – interleukin (IL)-17, IL-22, IL-23, IL-6, and IL-10 and the distribution and levels of immunoexpression IL-17, IL-23, and IL-1β within thyroid tissue were measured to characterize Th17 immune response in AITD. The integrity of the thyroid follicle by studying immunoexpression of cellular tight junctions – zonula occludens-1 and claudin-1 proteins, coupled to IL-17 and CD68, was explored. In addition, the selenium status was assessed. No significant differences in the plasma levels of Th17-associated cytokines were found among the patients with AITD and control subjects. However, the expression level of IL-17 in the thyrocytes was significantly higher in the HT and GD patients than in controls, simultaneously correlating with IL-23 and IL-1β immunopositivity in the HT group. Plasma Th17-associated cytokines’ levels were positively correlated with the severity of hyperthyroidism, independent of autoantibody levels, thus suggesting their possible role in GD pathogenesis. The changes in molecules of thyrocyte junctional complexes highlighting impairment of the integrity of thyroid follicle in HT were observed, but no significant association with IL-17 was found. Although no difference in selenium levels was observed between the AITD patients and controls, the results of the given research suggest the selenium status of the Latvian patients with newly diagnosed GD or HT is at a suboptimal level. Plasma selenium levels were negatively correlated with anti-thyroperoxidase (TPO) autoantibody titres in the HT patients, thus supporting the immunomodulatory role of selenium in AITD. Moreover, HT patients with higher anti-TPO autoantibody levels had lower levels of selenium, suggesting that these patients might benefit from selenium supplementation. Essential information deepening our knowledge about thyroid autoimmunity was obtained conducting this research, however, further experimental studies exploring the role and regulatory effects of Th17-related cytokines in the pathogenesis of AITD are required. More data from clinical studies are needed for a better understanding of the relationship between selenium supplementation and immune response.
  • No Thumbnail Available
    Item
    Thyroid Autoimmunity: Exploring the Role of Th17-associated Cytokines and Pathomorphological Mechanisms Involved in the Pathogenesis of Hashimoto’s Thyroiditis and Graves’ Disease. Summary of the Doctoral Thesis
    (Rīga Stradiņš University, 2021) Zaķe, Tatjana; Groma, Valērija; Konrāde, Ilze
    The prevalence and incidence of autoimmune thyroid diseases (AITD), presenting as Graves’ disease (GD) or Hashimoto’s thyroiditis (HT), has increased significantly in recent decades. It is crucial to identify immunological and pathomorphological factors involved in thyroid autoimmunity. Classically, HT has long been considered as a T helper (Th)1-mediated disease, while a Th2-driven autoimmune response is dominant for GD. Recently, Th17 cells have been established to play a role in the pathogenesis of AITD, however, their contribution to the initiation and progression of AITD remains unclear. Furthermore, selenium deficiency can impair the differentiation of Th cells, leading to dysfunction of cellular and humoral response. The aim of this thesis was to explore the role of Th17 cells in the pathogenesis of HT and GD by the use of different morphology methods and xMAP technology, and correlating these data with the selenium status. The initial study included 29 adult patients with AITD who underwent thyroidectomy, whereas subsequent clinical research project involved 52 patients with newly diagnosed, treatment-naïve AITD, as well as 26 healthy subjects served as controls. The plasma levels of Th17-associated cytokines – interleukin (IL)-17, IL-22, IL-23, IL-6, and IL-10 and the distribution and levels of immunoexpression IL-17, IL-23, and IL-1β within thyroid tissue were measured to characterize Th17 immune response in AITD. The integrity of the thyroid follicle by studying immunoexpression of cellular tight junctions – zonula occludens-1 and claudin-1 proteins, coupled to IL-17 and CD68, was explored. In addition, the selenium status was assessed. No significant differences in the plasma levels of Th17-associated cytokines were found among the patients with AITD and control subjects. However, the expression level of IL-17 in the thyrocytes was significantly higher in the HT and GD patients than in controls, simultaneously correlating with IL-23 and IL-1β immunopositivity in the HT group. Plasma Th17-associated cytokines’ levels were positively correlated with the severity of hyperthyroidism, independent of autoantibody levels, thus suggesting their possible role in GD pathogenesis. The changes in molecules of thyrocyte junctional complexes highlighting impairment of the integrity of thyroid follicle in HT were observed, but no significant association with IL-17 was found. Although no difference in selenium levels was observed between the AITD patients and controls, the results of the given research suggest the selenium status of the Latvian patients with newly diagnosed GD or HT is at a suboptimal level. Plasma selenium levels were negatively correlated with anti-thyroperoxidase (TPO) autoantibody titres in the HT patients, thus supporting the immunomodulatory role of selenium in AITD. Moreover, HT patients with higher anti-TPO autoantibody levels had lower levels of selenium, suggesting that these patients might benefit from selenium supplementation. Essential information deepening our knowledge about thyroid autoimmunity was obtained conducting this research, however, further experimental studies exploring the role and regulatory effects of Th17-related cytokines in the pathogenesis of AITD are required. More data from clinical studies are needed for a better understanding of the relationship between selenium supplementation and immune response.
  • No Thumbnail Available
    Item
    Vairogdziedzera autoimunitāte: ar Th17-asociēto citokīnu un patomorfoloģisko mehānismu izpēte Hašimoto tireoidīta un Greivsa slimības patoģenēzē. Promocijas darba kopsavilkums
    (Rīgas Stradiņa universitāte, 2021) Zaķe, Tatjana; Groma, Valērija; Konrāde, Ilze
    Pēdējo dekāžu laikā ievērojami pieaugusi tādu autoimūno vairogdziedzera slimību (AIVS) kā Greivsa slimība (GS) un Hašimoto tireoidīts (HT) saslimstība un izplatība. Ir būtiski identificēt imunoloģiskos un patomorfoloģiskos faktorus, kas iesaistīti vairogdziedzera autoimunitātes izcelsmē. Lai gan 1. un 2. tipa T līdzētājšūnu (Th) izmainīta aktivitāte AIVS patoģenēzē uzskatāma par pierādītu, nesen veiktie pētījumi liecina arī par iespējamu Th17 šūnu lomu AIVS attīstībā. Turklāt Th šūnu diferenciāciju var ietekmēt selēna deficīts, veicinot šūnu un humorālās imūnatbildes disfunkciju. Šī promocijas darba mērķis bija izpētīt Th17 šūnu nozīmi HT un GS patoģenēzē, lietojot dažādas morfoloģiskās diagnostikas metodes un xMAP tehnoloģiju, kā arī korelēt iegūtos datus ar selēna statusu. Sākotnēji pētījumā tika iekļauti 29 pieauguši pacienti ar AIVS, kuriem veikta tireoīdektomija, savukārt pētījuma klīniskā daļa ietvēra 52 pacientus ar pirmreizēji diagnosticētu, iepriekš neārstētu AIVS, kā arī 26 klīniski veselas pētāmās personas, kuras iekļautas kontroles grupā. Lai izvērtētu ar Th17 saistītu imūnatbildi AIVS ietvaros, tika mērīts ar Th17 saistīto citokīnu – interleikīna (IL)-17, IL-22, IL-23, IL-6 un IL-10 – līmenis plazmā, kā arī IL-17, IL-23 un IL-1β imūnekspresijas izplatība un līmenis vairogdziedzera audos. Vairogdziedzera folikulu integritāte tika pētīta, analizējot blīvo šūnu savienojumu jeb slēgjūgļu proteīnu zonula occludens-1 un klaudīna-1 imūnekspresiju un korelējot iegūtos datus ar IL-17 un CD68 ekspresiju. Papildus tam tika noteikts selēna statuss plazmā. Starp AIVS un kontroles grupas pacientiem statistiski ticamas ar Th17 saistīto citokīnu plazmas līmeņa atšķirības netika konstatētas. Tomēr IL-17 ekspresijas līmenis tireocītos bija ievērojami augstāks pacientiem ar HT un GS nekā kontroles grupas pētāmajām personām, vienlaicīgi korelējot ar IL-23 un IL-1β imūnpozitivitāti HT grupā. Tika noteikta statistiski nozīmīga pozitīva korelācija starp ar Th17 saistīto citokīnu līmeni plazmā un hipertireozes smaguma pakāpi, kas bija neatkarīga no autoantivielu līmeņa, tādējādi norādot uz to iespējamo lomu GS patoģenēzē. HT pacientu vairogdziedzera audos tika novērotas tireocītu slēgjūgļu molekulārās pārmaiņas, uzsverot vairogdziedzera folikulu integritātes bojājumu, taču to saistība ar IL-17 netika konstatēta. Nozīmīgai vairogdziedzera enzīmu daļai, kura nodrošina gan antioksidatīvo un pretiekaisuma funkciju, gan aktivē vairogdziedzera hormonus mērķa audos, funkcionālai aktivitātei nepieciešams pietiekams daudzums selēna, tādēļ selēna deficīts tiek saistīts ar AIVS patoģenēzi un pat terapiju. Lai gan mūsu pētījumā starp AIVS pacientiem un kontroles grupu netika noteiktas statistiski nozīmīgas atšķirības plazmas selēna līmenī, rezultāti pierāda, ka selēna statuss plazmā pirmreizēji diagnosticētiem GS un HT pacientiem Latvijā ir suboptimāls. Analizējot selēna līmeni plazmā HT pacientiem, iegūta statistiska nozīmīga negatīva asociācija ar autoantivielu pret tireoperoksidāzi (TPO) titru, tādējādi liecinot par selēna imūnmodulējošo lomu AIVS patoģenēzē. Turklāt HT pacientiem ar augstāku autoantivielu pret TPO līmeni tika novērots zemāks selēna līmenis plazmā, kas liek domāt, ka selēna papildterapija šiem pacientiem var sniegt ieguvumus. Veicot šo pētījumu, tika iegūta nozīmīga informācija, kas padziļina mūsu zināšanas par vairogdziedzera autoimunitātes patoģenēzi, kā arī ar Th17 saistīto citokīnu lomu un regulatoro ietekmi, tomēr būtu nepieciešami turpmāki pētījumi, lai vēl precīzāk izpētītu Th17 šūnu lomu AIVS patoģenēzē. Pētījums apstiprina arī nepietiekamu selēna līmeni plazmā AVS pacientiem, tomēr, lai izprastu saistību starp selēna papildterapiju un imūnatbildes reakciju, nepieciešams iegūt vairāk klīnisko pētījumu datu.