Cytokine expression in spleen affects progression of liver cirrhosis through liver-spleen cross-talk

AimIt is unclear whether the spleen affects the progression of liver cirrhosis (LC) through liver-spleen cross-talk. Transforming growth factor-1 (TGF-1) is reported to be the most potent cytokine of liver fibrosis, and interleukin-6 (IL-6) is an important factor of liver regeneration. In this study, we investigated the expression of cytokines in the spleens of LC patients in order to attempt to prove the existence of liver-spleen cross-talk. MethodsThe study enrolled 22 patients who underwent splenectomy at our institute between 2004 and 2010. TGF-1 expression in the resected spleen was measured using immunohistochemical staining. Two-color immunofluorescent staining for CD68 and TGF-1 in the spleen was performed to detect sources of TGF-1. IL-6 expression in the spleen was measured by reverse transcription polymerase chain reaction. ResultsTGF-1 expression was significantly higher in the spleens of LC patients than in those of patients with normal livers (P<0.05). Coexpression of CD68 and TGF-1 was confirmed. The expression of IL-6 in the spleens of LC patients was significantly lower than that in patients with normal livers (P<0.05). ConclusionTGF-1 produced by macrophages and cytokines such as IL-6 could affect the progression of liver fibrosis and regeneration in patients with LC via liver-spleen cross-talk.