Mobilization of hematopoietic progenitor cells in patients with liver cirrhosis.

AIM: To test the hypothesis that liver cirrhosis is associated with mobilization of hematopoietic progenitor cells. METHODS: Peripheral blood samples from 72 patients with liver cirrhosis of varying etiology were analyzed by flow cytometry. Identified progenitor cell subsets were immunoselected and used for functional assays in vitro. Plasma levels of stromal cell-derived factor-1 (SDF-1) were measured using an enzyme linked immunosorbent assay. RESULTS: Progenitor cells with a CD133(+)/CD45(+)/CD14(+) phenotype were observed in 61% of the patients. Between 1% and 26% of the peripheral blood mononuclear cells (MNCs) displayed this phenotype. Furthermore, a distinct population of c-kit(+) progenitor cells (between 1% and 38% of the MNCs) could be detected in 91% of the patients. Additionally, 18% of the patients showed a population of progenitor cells (between 1% and 68% of the MNCs) that was characterized by expression of breast cancer resistance protein-1. Further phenotypic analysis disclosed that the circulating precursors expressed CXC chemokine receptor 4, the receptor for SDF-1. In line with this finding, elevated plasma levels of SDF-1 were present in all patients and were found to correlate with the number of mobilized CD133(+) progenitor cells. CONCLUSION: These data indicate that in humans, liver cirrhosis leads to recruitment of various populations of hematopoietic progenitor cells that display markers of intrahepatic progenitor cells.

Biochemical and histological effects of 26 weeks of glycyrrhizin treatment in chronic hepatitis C: a randomized phase II trial.

BACKGROUND/AIMS: Phase I/II studies of 4 weeks duration have confirmed the ALT lowering effect of glycyrrhizin in Western chronic hepatitis C patients. Our aim was to determine the dose frequency of glycyrrhizin required to maintain the ALT response beyond 4 weeks and evaluate its effect on liver histology and quality of life. METHODS: HCV-RNA-positive patients with elevated ALT and marked fibrosis or necro-inflammation who were not eligible for interferon therapy were treated for 4 weeks with six infusions weekly of glycyrrhizin. Patients with an ALT response at week 4 were randomized to continue treatment for 22 weeks in three dose frequency groups: 6x, 3x or once weekly. RESULTS: 72/121 (60%) patients were randomized. At the end of treatment the ALT response was maintained in 60%, 24% and 9% of patients in the 6x, 3x, and once weekly groups, respectively (p<0.001). In ALT responders the necro-inflammation score improved non-significantly compared to ALT non-responders. Quality of life assessed by SF-36 increased in patients treated with the study drug, albeit unrelated to the occurrence of ALT response. CONCLUSIONS: ALT responses induced by 4 weeks glycyrrhizin therapy can be maintained in a subset of chronic hepatitis C patients receiving at least three injections weekly. The observed ALT response did not translate in a significant histological improvement after 6 months treatment.

Partial hepatectomy induces mobilization of a unique population of haematopoietic progenitor cells in human healthy liver donors.

BACKGROUND/AIMS: Recent studies indicate that after transplantation, circulating bone marrow-derived stem cells migrate into the liver and contribute to liver regeneration. Whether such cells are actively recruited from the bone marrow for liver repair remains to be determined. In this regard, we investigated whether liver resection leads to a release of stem cell marker-positive (+) cells into the peripheral circulation. METHODS: Peripheral blood samples from 11 living liver donors were analyzed by flow cytometry one day before and 12h after partial hepatectomy (PH) using antibodies against CD133, CD34, CD45, CD14, c-kit, bcrp-1. Immunomagnetic separation was performed to select CD133+ cells for functional assays in vitro. RESULTS: A significant increase in the percentage of CD133+ cells could be demonstrated in all donors studied. Unexpectedly, virtually all CD133+ cells coexpressed CD45 and CD14, whereas only a small subset expressed CD34. No significant staining was observed for c-kit and bcrp-1. In culture, immunoselected CD133+ cells displayed characteristics of myelomonocytic precursors. In addition, enriched CD133+ generated an adherent cell population that expressed CK8, alpha-fetoprotein, and human albumin. CONCLUSIONS: PH induces mobilization of a distinct population of myelomonocytic progenitor cells, which have hepatic differentiation potential in vitro, and might play a role in liver regeneration after PH in humans.

Synthesis and biological evaluation of 1,2,4-triazinylphenylalkylthiazolecarboxylic acid esters as cytokine-inhibiting antedrugs with strong bronchodilating effects in an animal model of asthma.

The influx of leukocytes (eosinophils, lymphocytes, and monocytes) into the airways and their production of proinflammatory cytokines contribute to the severity of allergic asthma. We describe here the synthesis and pharmacological evaluation of a series of triazinylphenylalkylthiazolecarboxylic acid esters that were designed to act as lung-specific antedrugs and inhibitors of the production of interleukin (IL)-5, a primary eosinophil-activating and proinflammatory cytokine. Closer examination of the hydroxypropyl ester, 15, indicated its high metabolic stability (t(1/2) > 240 min) in human lung S9 fraction but rapid conversion (t(1/2) = 15 min) into the pharmacologically inactive carboxylic acid by human liver preparations. In stimulated human whole blood cultures, 15 reduced not only the production of IL-5 (IC(50) = 78 nM) but also the biosynthesis of the monocyte chemotactic proteins MCP-1 (IC(50) = 220 nM), MCP-2 (IC(50) = 580 nM), and MCP-3 (IC(50) = 80 nM). In vivo, intratracheal administration of 15 (6 mg/animal) to allergic sheep, either before (-4 h) or after (+1.5 h) the pulmonary allergen challenge, completely abrogated the late-phase airway response and reduced the bronchial hyperreactivity to inhaled carbachol.

Recurrent deep-vein thrombosis based on homozygous factor V Leiden mutation acquired after liver transplantation.

Several genetic liver diseases can be treated by liver transplantation (LT). However, some genetic defects also may be acquired by this procedure. We describe a patient who developed recurrent deep-vein thromboses after LT for hepatitis C virus-associated hepatocellular carcinoma on the basis of a homozygous Leiden mutation of the factor V gene in the donor liver. Liver donors with a history of venous thrombosis should be screened for the presence of activated protein C (APC) resistance. In addition, we recommend looking for APC resistance in liver recipients who develop venous thromboembolic disease in the post-LT course. Molecular analysis of donor tissue may be necessary to make a definite diagnosis of factor V Leiden mutation in these patients. As a consequence, intensified postoperative thromboprophylaxis or lifelong anticoagulant therapy may be necessary if this thrombophilic gene defect is detected.

Granzyme expression in fine-needle aspirates from liver allografts is increased during acute rejection.

We investigated whether determination in fine-needle aspiration biopsy (FNAB) specimens of cells expressing granzymes (Grs) and Fas ligand would provide a reliable, easy, and quantitative measure of rejection activity in the transplanted liver. Retrospectively, 13 FNAB specimens obtained during clinical acute rejection, 10 FNAB specimens obtained during subclinical rejection, 12 FNAB specimens obtained during cytomegalovirus (CMV) infection, and 26 FNAB specimens obtained in the absence of rejection or infection were included on the study. Cytospin preparations of FNAB and peripheral-blood specimens were immunocytochemically stained for Fas-ligand and Gr, and increments in the liver were calculated by subtracting frequencies of positive cells in blood from those in FNAB specimens. Only sporadically Fas ligand-expressing, but many Gr-expressing, cells were detected in FNAB specimens. Increments in Gr-positive (Gr(+)) cells were significantly greater in FNAB specimens obtained during clinical rejection (median, 70 Gr(+) cells; range, 0 to 312 Gr(+) cells; P = .006) and tended to be greater in FNAB specimens obtained during subclinical rejection (median, 62 Gr(+) cells; range, 5 to 113 Gr(+) cells; P = .09) compared with those obtained in the absence of rejection (median, 16 Gr(+) cells; range, 0 to 103 Gr(+) cells). Increments obtained during clinical or subclinical rejection did not differ from those obtained during CMV infection (median, 27 Gr(+) cells; range, 6 to 212 Gr(+) cells). With the exclusion of specimens obtained during CMV infection, the sensitivity of Gr determination in FNAB specimens for the diagnosis of acute rejection (either clinical or subclinical) was 70%, and specificity, 69%. In FNAB specimens obtained during clinical and subclinical acute rejection episodes after liver transplantation, increased numbers of Gr-expressing cells were present; in the absence of CMV infection, their quantification provides a measure for rejection activity with moderate accuracy.

Synthesis and anti-angiogenic activity of 6-(1,2,4-thiadiazol-5-yl)-3-amino pyridazine derivatives.

General screening for inhibitors of microvessel growth in vitro in the rat aortic ring assay led to the discovery of a novel series of thiadiazole pyridazine compounds with potential anti-angiogenic activity. Chemical optimization produced orally active compounds with potent in vitro and in vivo anti-angiogenesis and anti-tumor activities.