[5, 6] Some authors have reported that autologous BM cell infusion therapy improved the clinical symptoms and biochemical data by activating the progenitor cell compartment and enhancing PLX4032 mouse hepatocyte proliferation in patients with decompensated liver cirrhosis (LC).[7, 8] Although HSC are a potential source of cells for liver repopulation, the mechanisms and kinetics of HSC mobilization in patients with chronic liver disease (CLD) are poorly understood.[9, 10] To clarify

whether the number of circulating HSC in CLD patients is higher or lower than that in healthy controls, we determined the numbers of CD34+ cells and colony-forming unit culture (CFU-C) using flow cytometry and colony assays, respectively, in peripheral blood (PB) samples from patients with hepatitis C virus (HCV)-associated CLD. We found that both of these factors decreased with the progression of liver disease unlike in previous reports.[9, 10] In humans, the spleen plays a principal role in blood formation 5-Fluoracil in vitro during fetal development, but this function rapidly diminishes after birth. Therefore, the spleen is not believed to contribute to hematopoiesis in healthy individuals.[11]

Recently, however, several reports have demonstrated that the spleen in adults contains a significant number of HSC.[12, 13] Splenectomy was reported to increase the number of platelets and leukocytes, and to reduce the number of long-lived memory B cells.[14-16] Splenectomy is performed to improve thrombocytopenia in cirrhotic HCV patients being treated with pegylated interferon (IFN)-α and ribavirin.[17] However, the effects of splenectomy on circulating HSC have not been determined. Therefore, in this study, we determined the number of circulating HSC before and after splenectomy in patients with LC, and confirmed that the number of HSC increased

significantly find more after splenectomy, an effect that persisted for a long time. Forty-eight patients (22 men, 26 women; mean ± standard deviation age, 56 ± 12 years) with HCV-associated CLD, who were followed up at the Mie University Hospital between February and December 2004, were included in this study to assess the association between the number of circulating HSC and CLD stage. The presence of HCV was confirmed by a positive reverse transcription polymerase chain reaction for HCV RNA at diagnosis. The patients were subdivided into the following four groups using a combination of laboratory tests, abdominal ultrasonography and computed tomography: (i) nine patients with an asymptomatic carrier state (ASC); (ii) nine patients with chronic active hepatitis (CAH); (iii) 15 patients with LC; and (iv) 15 patients with LC and hepatocellular carcinoma (LC + HCC).