Association of Serum IL-۳۵ and TGF-β Levels with the Incidence, Severity, and Treatment Response in Iraqi Patients with Graves’ Disease

Background & Objective: Graves’ disease (GD) is a common autoimmune thyroid disorder characterized by thyroid hormone hypersecretion and autoantibody formation against the thyrotropin receptor (TRAb). Interleukin-۳۵ (IL-۳۵), a novel immunosuppressive cytokine of the IL-۱۲ family secreted primarily by regulatory T and B cells, has been implicated in the modulation of autoimmune responses. Transforming growth factor β (TGF-β) is a cytokine with immunoregulatory properties that plays a central role in T-regulatory cell differentiation. This study aimed to investigate serum IL-۳۵ and TGF-β levels in Iraqi patients with GD and assess their association with disease severity, clinical manifestations, and response to carbimazole therapy.Methods: A total of ۱۰۳ participants were enrolled, including ۶۶ patients with GD (mean age, ۴۱.۶ [SD, ۱۳.۹۵] years) and ۳۷ healthy controls (mean age, ۳۷.۴۳ [SD, ۱۰.۲۵] years). Serum IL-۳۵ and TGF-β concentrations were measured using enzyme-linked immunosorbent assay (ELISA).Results: IL-۳۵ levels were significantly reduced in untreated GD patients compared with healthy controls and partially increased after carbimazole therapy (P < .۰۰۱). TGF-β levels were highest in untreated patients and declined after treatment (P < .۰۰۱). IL-۳۵ showed no correlation with FT۳, FT۴, or TRAb but was elevated in patients with disease duration longer than ۵ years (P = .۰۴۶) and in those with severe exophthalmos (P = .۰۳). TGF-β levels were inversely correlated with FT۳, FT۴, and TRAb (P < .۰۵) and were higher in carbimazole nonresponders and in patients with severe exophthalmos (P < .۰۵).Conclusion: IL-۳۵ may serve as a promising biomarker for monitoring disease activity, prognosis, and therapeutic response in patients with GD.

کلیدواژه ها:

Graves’ disease ، IL-۳۵ ، TGF-β ، thyrotropin receptor antibody ، carbimazole