Analysis Of T-Cell Cytokines Among Patients With Oral Chronic Graft-Versus-Host-Disease After Allogeneic Hematopoietic Stem Cell Transplantation

Objectives:To investigate the levels of T-cell cytokines[Thl(IFN-γ, IL-12), Th2 (IL-4, IL-6, IL-10), Th17 (IL-17A, IL-23), Treg (TGF-β)] among patients with oral chronic graft-versus-host-disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (Allo-HSCT), and to assess the influence of T-cell cytokine levels on oral manifestations, and on the pathophysiological mechanism of oral cGVHD.Methods:Ninety patients undergone Allo-HSCT were recruited as transplantation group, including 44 (3-thalassemia major patients (thalassemia group) and 46 patients (leukemia group), of which 21 patients were diagnosed with oral cGVHD respectively. All patients were required to answer the provided questionnaire for collection of essential informations, and were subjected to oral examinations. In oral cGVHD patients, score of oral manifestations were recorded according to the criteria by National Institutes of Health (NIH) 2014 guidelines, and pain score by visual analogous scale (VAS) criteria. Similarly, blood samples of all the participants were collected. No saliva samples could be collected from thalassemia group because of the difficulties in patient compliance. Thus, only 18 saliva samples were collected from leukemia group of oral cGVHD patients. Eighteen healthy volunteers, matched by age and gender based on the oral cGVHD patients of leukemia group, were selected as healthy controls (HC), both blood and saliva samples were collected from them as well. T-cell cytokines [Th1 (IFN-y, IL-12), Th2 (IL-4, IL-6, IL-10), Th17 (IL-17A, IL-23), Treg (TGF-β)] levels of both groups were detected by cytometric bead array (CBA) or enzyme-linked immunosorbent assay (ELISA), and then described by median and inter-quartile range (IQR), while, the scores of oral manifestations and VAS by performing mean and standard deviation calculations. Comparisons among T-cell cytokines were analyzed by Mann-Whitney U test, and further correlations among cytokines, scores of oral manifestations and VAS were assessed by Spearman rank correlation or logistic regression analysis.Results:1. Oral manifestations of cGVHD patients:The prevalences of oral cGVHD in thalassemia and leukemia groups were 47.73% and 45.65% respectively. Xerostomia and pain were major complaints. Hyperkeratotic white lines were observed in all patients. Ulcer, erosion and erythema-like lesion were the most common oral manifestations, however, vesicle, atrophy of lingual papilla, herpetic stomatitis, rhagades of lip, pseudomembrane and trismus could be found away on certain patients. In cGVHD patients of the two groups, the mean scores of oral manifestations were 3.95±1.77 (thalassemia group) and 3.52±2.32 (leukemia group), while the mean scores of VAS were 2.90±2.30 (thalassemia group) and 3.43±1.81 (leukemia group), respectively, and no statistical difference was found. Similarly, there was no significant correlation between scores of manifestations and VAS.2. The levels of T-cell cytokines in serum of patients with or without oral cGVHD:In thalassemia and leukemia groups, among oral cGVHD patients, serous IL-4, IL-6, IL-10 and IL-23 levels were higher, while the level of TGF-β was lower than those of non-oral cGVHD patients. The levels of IL-6, IL-23 were negatively related to that of TGF-β. The scores of oral manifestations were positively related to IL-6, IL-23 levels, while, negatively related to TGF-β level. By logistic regression analysis, oral cGVHD was positively related to IL-23 level, negatively related to TGF-β level.3. The levels of T-cell cytokines in serum and saliva of oral cGVHD in leukemia group and HC:Serous IL-4, IL-6, IL-10 levels of oral cGVHD patients were higher than those of HC, while levels of salivary IL-6, IL-10 were higher. The scores of oral manifestations were positively related to salivary IL-6 level.Conclusions:According to our study, Th2, Th17 and Treg cytokines (IL-4, IL-6, IL-10, IL-23, TGF-β) might play a significant role in pathogenesis of oral cGVHD. High level of IL-23 might be a risk factor, while TGF-β might be a protective factor of oral cGVHD.