Evaluation of the expression of T helper lymphocytes markers associated with Th1, Th2, Th17 and Treg cells in primary pterygium biopsies Evaluación de la expresión de marcadores asociados a linfocitos T cooperadores del tipo Th1, Th2, Th17 y Treg en biopsias de pterigión primario

© 2017 Sociedad Mexicana de Oftalmología. Introduction: Various pro-inflammatory cytokines and growth factors have been implicated in the pathogenesis of pterygium (Pt); however, the effect of cytokines produced by helper T lymphocytes (Th) has been poorly studied. To date, only interleukin 4 (IL-4) from Th lymphocytes has been linked to Pt recurrence. Therefore, this study aimed to evaluate the expression of Th cytokines and Th transcription factors in primary Pt. Methods: Pt biopsies were obtained from 28 eyes of 28 Mexican patients undergoing primary excision of Pt with conjunctival autograft. Conjunctival biopsies of 8 patients undergoing cataract surgery were used as the control group. Gene expression of Th cytokines - interferon gamma (IFN-¿), IL-13, IL-17, IL-10-, as well as gene expression of Th transcription factors T-bet, GATA3, Foxp3 and ROR¿t, was analyzed by real-time RT-PCR. results: We found decreased expression of markers T-bet, GATA3, ROR¿t, IFN- ¿, IL-13 and IL-10 in Pt. We found a sixfold increase in the expression of IL-17 and Foxp3 in Pt compared to healthy conjunctiva (p < 0.0001); this increase was dependent on Pt size. Conclusions: The increased expression of IL-17 and Foxp3 in Pt samples suggests the presence of IL-17+ Foxp3+ Th lymphocytes, a subset of the Th population with the ability to suppress T cell proliferation and promote tumor progression. Therefore, IL17+ Foxp3+ Th cells may be involved in the occurrence and growth of Pt.

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