Cytokines are early diagnostic biomarkers of graft-versus-host disease in liver recipients

BACKGROUND： Graft-versus-host disease （GVHD） is associated with high mortality. Early diagnosis is essential to start treatment and to improve outcomes. Because of the inflammatory nature, we hypothesis that cytokine profile of patients with GVHD may serve as diagnostic markers. The present study was to evaluate the role of cytokine profile in the diagnosis of GVHD. METHODS： An immunoassay was used to detect 29 cytokines simultaneously in the serum; the measuring sensitivity of all cytokines was pg/mL. Healthy subjects undergoing annual routine physical examinations served as negative controls; 23 patients with hepatocellular carcinoma （HCC） who had undergone liver transplantation （the LT group） comprised the test subjects. A total of 22 kidney recipients with biopsyconfirmed GVHD （the RT group） were included for comparison. HCC patients with radical surgery （the HCC group, n=22） served as positive control. The liver contents of the three cytokines, IL-2, IL-18, and IFN-γ, were detected with immunohistochemistry. Serum granzyme B and perforin were measured by flow cytometry.RESULTS： Of the 29 cytokines, the levels of IL-2 and IL-18 were increased significantly in liver recipients with GVHD compared with healthy controls （P〈0.05）. The serum levels of these three cytokines in the healthy, HCC, LT, and RT groups were IL-2： 0.90±0.02, 4.14±0.61, 5.10±0.89, and 1.48±0.09 pg/mL; IL-18： 80.61±9.35, 109.51±10.93, 230.11±12.92, and 61.98±7.88 pg/mL; IFN-γ： 24.06±3.88, 24.84±3.21, 40.37±5.88, and 15.33±4.72 pg/mL, respectively. Immunohistochemistry showed that these 3 cytokines expressions in the liver were parallel to the serum cytokine. After standard anti-GVHD treatment, the expressions of IL-2, IL-18, and IFN-y were de- creased in the liver （P〈0.05）. Serum granzyme B and perforin were significantly increased in GVHD patients （P〈0.05）. CONCLUSIONS： IL-2, IL-18 and IFN-γ were from liver and might serve as biomarkers for monitoring GVHD develop- ment and the effects of anti-GVHD treatment. Granzyme B and perforin may play a role in increasing IL-2, IL-18, and IFN-y levels in GVHD patients.