Can Serum and Saliva Inflammatory Cytokines Be Considered a Reliable Marker in Chronic Oral Graft-Versus-Host Disease Patients?

<b>Background/Objectives:</b> Chronic graft-versus-host disease (cGVHD) and oral lichen planus (LPO) are chronic inflammatory conditions with similar oral manifestations. This study aimed to assess whether serum and salivary cytokines (IL-1α, IL-6, IL-17) could serve as reliable biomarkers for cGVHD. <b>Methods:</b> A prospective cohort study was conducted involving cGVHD patients, LPO patients, and healthy controls. Cytokine levels in serum and saliva were measured by ELISA and compared across the groups using the Kruskal-Wallis test. <b>Results:</b> IL-17 levels were significantly elevated in the serum of cGVHD patients compared to LPO patients and controls (<i>p</i> < 0.05). However, IL-6 and IL-1α did not show significant differences among the groups. A comparison of salivary samples between the three groups did not reach statistical significance (<i>p</i> > 0.05). <b>Conclusions:</b> This study suggests that IL-17 could be a potential biomarker for cGVHD-related inflammation, warranting further investigation. Salivary samples do not seem to be a reliable biological marker for the diagnosis of cGVHD. The findings underline the need for larger studies to validate these preliminary results.