Serum Concentrations of Th1, Th2 and Treg‐Associated Cytokines in Patients With Ocular Toxoplasmosis

Ocular toxoplasmosis (OT) is a common cause of posterior uveitis worldwide, primarily caused by Toxoplasma gondii . The immune response plays a crucial role in OT pathogenesis. However, a study using aqueous humour samples has limited applicability due to the invasive procedure. This study used peripheral blood samples to compare the concentrations and ratios of cytokines involved in Th1, Th17 and Treg immune responses between OT patients and seropositive individuals without ocular lesions (SP) who met the inclusion criteria. The ELISA method was used to measure cytokine concentrations, and the cytokine ratio was determined by comparing the concentration of two cytokines. This study revealed the differences in the concentrations of IL‐17 ( p = 0.015), IFN‐α ( p = 0.015) and IL‐6 ( p = < 0.001) between OT and SP groups, as well as the ratio of IFN‐α/TGF‐β ( p = 0.012), IFN‐β/TGF‐β ( p = 0.020), IL‐17/TGF‐β ( p = 0.018), TNF‐α/TGF‐β ( p = 0.015), IL‐17/IL‐6 ( p = 0.003), IL‐6/IFN‐γ ( p = < 0.001) and IL‐6/TNF‐α ( p = < 0.001). Among the variables, the IFN‐α concentrations and IL‐6/TNF‐α ratio were the most significant factors influencing the risk of OT. The novel findings of this study regarding the involvement of IFN‐α in the pathogenesis of OT are considered important and have the potential to reveal a predictive factor for the occurrence of OT in humans.