Features of local and systemic production of major immune response cytokines in epithelial lacrimal gland tumors

Investigation of the cytokine profile in tear fluid (TF) as a local environment, as well as in blood serum (BS), which reflects systemic immune status, may provide valuable information on the pathogenetic features and biological behavior of epithelial lacrimal gland tumors (LGTs). Objective. The study aimed to investigate changes in the levels of key cytokines associated with the immune response (IL-6, TNF-α, IL-2, IFN-γ, IL-17A, IL-4, IL-10) in TF and BS of patients with epithelial LGTs. Material and methods. The study examined 21 participants, including 10 healthy volunteers and 11 patients with epithelial LGTs (pleomorphic adenoma (PA) was diagnosed in 6 cases and lacrimal gland cancer (LGC) — in 5 cases). Cytokine levels in test samples were determined by multiplex analysis (CBA platform) using a flow cytometer. The analysis accounted for both the concentration of immunomediators and the frequency of their detection in the tested material. Results. Patients with PA and LGC showed changes in both the qualitative and quantitative composition of proinflammatory and anti-inflammatory mediators. In TF of patients with LGC, the highest concentrations of IL-6, TNF-α, IL-17A, and IL-10 were observed, mainly on the affected side. Patients with PA also showed elevated levels of IL-6, TNF-α, and IL-17A compared with the corresponding control values, but cytokine activation was less pronounced than in LGC. The analysis showed that assessment of TNF-α levels in TF is the most promising diagnostic marker of LGC: elevated concentrations of this cytokine were detected on the tumor side in all patients and were almost 20-fold higher than in PA (p<0.05 when comparing LGC patients with controls and the tumor side in LGC with PA). In BS the differences between the groups were less pronounced and not indicative. Conclusion. The obtained data allow the local cytokine profile to be considered as an additional noninvasive tool for differential diagnosis between benign and malignant epithelial LGTs.