Steroid-refractory GVHD: T-cell attack within a vulnerable endothelial system.
Department of Medicine V, University of Heidelberg, Heidelberg, Germany;
Acute graft-versus-host disease (GVHD) is a major complication of allogeneic stem cell transplantation (SCT) and can be readily controlled by systemic high-dose steroids in many patients. However, patients whose GVHD is refractory to this therapy have a poor prognosis. Refractory patients have ongoing end-organ damage despite effective immunosuppression with second-line regimens, suggesting pathomechanisms independent from the initiating T-cell attack. To explore whether endothelial damage might contribute to GVHD refractoriness and to study the role of angiopoietin-2 (ANG2) in this process, we have compared kinetics of T-cell activation markers and markers of endothelial dysfunction in the serum of patients with sensitive (n = 23) and refractory GVHD (n = 25). Longitudinal measurements of soluble FAS ligand along with other immune markers demonstrate that refractory patients are not exposed to an overwhelming or unresponsive T-cell attack. However, in contrast to sensitive GVHD, refractory GVHD was associated with rising thrombomodulin levels and high ANG2/ vascular endothelial-derived growth factor ratios. Patients with refractory GVHD showed significantly increased ANG2 levels already before SCT. These results suggest that endothelial cell vulnerability and dysfunction, rather than refractory T-cell activity, drives treatment refractoriness of GVHD and opens new avenues for prediction and control of this devastating condition.
Serum biomarkers of cell death for monitoring therapy response of gastrointestinal carcinomas.
Brandt D, Volkmann X, Anstätt M, Länger F, Manns MP, Schulze-Osthoff K, Bantel H.
Eur J Cancer. 2010 Mar 2. [Epub ahead of print]
Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany.
PURPOSE: Antitumour treatments are thought to exert their therapeutic efficacy mainly by induction of apoptosis in tumour cells. In epithelial cells, caspases, the key enzymes of apoptosis, cleave the intermediate filament protein cytokeratin (CK)-18 into specific fragments that are released into circulating blood and can be detected by a specific ELISA.
EXPERIMENTAL DESIGN: To investigate the use of CK-18 fragments as a potential biomarker for the treatment response, we examined the association of serum CK-18 levels and clinical response in 35 patients with gastrointestinal cancers. RESULTS: While both cleaved and total CK-18 levels were intrinsically elevated in tumour patients, they were further increased during 5-fluorouracil (5-FU)-based therapy. Importantly, the increased levels of CK-18 could discriminate between patients with different clinical response. Cancer patients with a partial response or stable disease revealed a significantly higher increase of cleaved CK-18 during chemotherapy as compared to patients with progressive disease.
CONCLUSIONS: Our results suggest that detection of circulating caspase-cleaved CK-18 might be a useful serum biomarker for monitoring treatment response and should merit further evaluation in larger patient groups.
Cancer Biol Ther. 2010 Apr 20;9(8). [Epub ahead of print]
Conatumumab, a fully human agonist antibody to death receptor 5, induces apoptosis via caspase activation in multiple tumor types.
Kaplan-Lefko PJ, Graves JD, Zoog SJ, Pan Y, Wall J, Branstetter DG, Moriguchi J, Coxon A, Huard JN, Xu R, Peach ML, Juan G, Kaufman S, Chen Q, Bianchi A, Kordich JJ, Ma M, Foltz IN, Gliniak BC.
Amgen Inc., Thousand Oaks, CA, USA. pkaplan@amgen.com.
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) binds to death receptors 4 and 5 (DR4, DR5) to transduce apoptotic signals. Conatumumab (AMG 655) is an investigational, fully human monoclonal agonist antibody (IgG(1)) to human DR5, which induces apoptosis via caspase activation. In this study, we demonstrate that conatumumab binds to DR5, activating intracellular caspases in vitro in the presence of a cross-linker. We also show that conatumumab has activity in vivo and inhibits tumor growth in colon (Colo205 and HCT-15), lung (H2122) and pancreatic (MiaPaCa2/T2) xenograft models. Conatumumab also enhances the anti-tumor activity of chemotherapeutics in vivo. Caspase activation in Colo205 tumors is dose-dependent and correlated with serum concentrations of conatumumab. We demonstrate for the first time that increases in serum caspase-3/7 activity and levels of M30 (neoepitope of caspase-cleaved cytokeratin-18) are linked to activation of the extrinsic apoptotic pathway using conatumumab in a preclinical model. These data suggest that conatumumab has potential as a therapeutic agent for treating patients with multiple tumor types, and that serum caspase-3/7 and M30 levels may serve as biomarkers of conatumumab activity.
Cancer Biomark. 2009;5(3):117-25.
Specific demonstration of drug-induced tumour cell apoptosis in human xenografts models using a plasma biomarker.
Olofsson MH, Cummings J, Fayad W, Brnjic S, Herrmann R, Berndtsson M, Hodgkinson C, Dean E, Odedra R, Wilkinson RW, Mundt KE, Busk M, Dive C, Linder S.
Cancer Center Karolinska, Department of Oncology and Pathology, Karolinska Institute and Hospital, Stockholm, Sweden.
Pharmacodynamic (PD) assays should be used before advancing new drugs to clinical trials. Most PD assays measure the response to drugs in tissue, a procedure which requires tissue biopsies. The M30-Apoptosense ELISA is a PD biomarker assay for the quantitative determination of caspase-cleaved cytokeratin 18 (CK18) released from apoptotic carcinoma cells into blood. We here demonstrate that whereas the M30-Apoptosense ELISA assay detects human caspase-cleaved CK18, the mouse and rat CK18 caspase cleavage products are detected with low affinity. The M30-Apoptosense ELISA therefore facilitates the determination of drug-induced apoptosis in human tumour xenografts in rodents using plasma samples, largely independently from host toxicity. Increases of caspase-cleaved CK18 were observed in plasma from different carcinoma xenograft models in response to anticancer drugs. The appearance caspase-cleaved CK18 in plasma was found to reflect formation of the caspase-cleaved epitope in FaDu head-neck carcinomas and in cultured cells. The M30-Apoptosense assay allows determination of tumour response in blood from xenograft models and from patients, providing a powerful tool for translational studies of anticancer drugs.
J Clin Gastroenterol. 2010 Jan 25. [Epub ahead of print]
Serum Fragmented Cytokeratin 18 Levels Reflect the Histologic Activity Score of Nonalcoholic Fatty Liver Disease More Accurately Than Serum Alanine Aminotransferase Levels.
Tsutsui M, Tanaka N, Kawakubo M, Sheena Y, Horiuchi A, Komatsu M, Nagaya T, Joshita S, Umemura T, Ichijo T, Matsumoto A, Yoshizawa K, Aoyama T, Tanaka E, Sano K.
Departments of *Molecular Oncology daggerMetabolic Regulation, Institute on Aging and Adaptation, Shinshu University Graduate School of Medicine double daggerDepartment of Gastroenterology, Shinshu University School of Medicine section signDepartment of Laboratory Medicine, Shinshu University Hospital parallelDepartment of Economics, Shinshu University paragraph signDepartment of Gastroenterology, Showa Inan General Hospital, Japan.
Abstract
BACKGROUND AND GOALS: Reliable noninvasive biomarkers to assess the histologic activity of nonalcoholic fatty liver disease (NAFLD) have not been established. As the frequency of Mallory bodies is known to be closely associated with the disease severity, we hypothesized that serum levels of Mallory body-related proteins were correlated with NAFLD histologic activity and evaluated this possibility. STUDY: Serum levels of total and fragmented cytokeratin (CK) 18, heat shock protein (Hsp) 70, Hsp90alpha, ubiquitin+1, and p38alpha at the time of liver biopsy were measured in 118 NAFLD patients and their association with histologic findings and NAFLD histologic activity score (NAS) was investigated. RESULTS: Serum levels of both forms of CK18 and Hsp90alpha were markedly higher in patients having nonalcoholic steatohepatitis (NASH) compared with non-NASH ones. Both forms of CK18 significantly correlated with degree of steatosis, lobular inflammation, and ballooning, and showed stronger positive correlations with NAS than serum aspartate and alanine aminotransferase (AST and ALT). Multiple regression analysis further revealed that fragmented CK18 and AST were effective predictors of NAS, with the former being the more definitive of the two (P<0.001 vs. 0.005). In 20 NAFLD patients who received a follow-up biopsy, changes in fragmented CK18 levels, but not AST or ALT levels, closely paralleled those in NAS. CONCLUSIONS: These results establish the usefulness of fragmented CK18 measurement for assessing and monitoring the histologic activity of NAFLD.
Hepatology. 2009 Oct;50(4):1072-8.
Cytokeratin-18 fragment levels as noninvasive biomarkers for nonalcoholic steatohepatitis: a multicenter validation study.
Feldstein AE, Wieckowska A, Lopez AR, Liu YC, Zein NN, McCullough AJ.
Department of Pediatric Gastroenterology, Cleveland Clinic, Cleveland, OH 44195, USA. feldsta@ccf.org
Liver biopsy remains the gold standard for diagnosing nonalcoholic steatohepatitis (NASH). We have recently demonstrated that plasma cytokeratin 18 (CK-18) fragment levels correlate with the magnitude of hepatocyte apoptosis and independently predict the presence of NASH. The goal of this study was to validate the use of this biomarker for NASH diagnosis. The study was an ancillary study of the NASH Clinical Research Network (NASH CRN). Our cohort consisted of 139 patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) from eight CRN participant centers across the United States and 150 age-matched healthy controls. CK-18 fragments were measured using a specific enzyme-linked immunosorbent assay. Histology was assessed centrally by study pathologists. CK-18 fragments were markedly increased in patients with NASH versus those without NASH and borderline diagnosis (median [25th, 75th percentile], 335 [196, 511], 194 [151, 270], 200 [148, 284], respectively; P < 0.001). Moreover, the odds of having fibrosis on liver biopsy increased with increasing plasma CK-18 fragment levels (P < 0.001). On multivariate regression analysis, CK-18 fragments remained an independent predictor of NASH after adjusting for variables associated with CK-18 fragments or NASH on univariate analysis (fibrosis, alanine aminotransferase, aspartate aminotransferase, age, biopsy length). The area under the receiver operating characteristic curve for NASH diagnosis was estimated to be 0.83 (0.75, 0.91).
CONCLUSION: Determination of CK-18 fragments in the blood predicts histological NASH and severity of disease in a large, diverse population of patients with biopsy-proven NAFLD, supporting the potential usefulness of this test in clinical practice.
Crit Care. 2009;13(3):R93. Epub 2009 Jun 18.
Cell death serum biomarkers are early predictors for survival in severe septic patients with hepatic dysfunction.
Hofer S, Brenner T, Bopp C, Steppan J, Lichtenstern C, Weitz J, Bruckner T, Martin E, Hoffmann U, Weigand MA.
Department of Anaesthesiology, University of Heidelberg, Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany. Stefan.Hofer@med.uni-heidelberg.de
INTRODUCTION: Severe sepsis, septic shock, and resulting organ failure represent the most common cause of death in intensive care medicine, with mortality ranging from 40% to 70%. It is still unclear whether necrosis or apoptosis plays the predominant role in severe sepsis. Determining the prevalent mode of cell death would be valuable, as new therapeutic agents (eg, antiapoptotic drugs such as caspase inhibitors) may improve unsatisfactory outcomes in patients with severe sepsis. Furthermore, the prognostic value of newly developed cell death serum biomarkers is of great interest.
METHODS: In total, 147 patients (101 patients with severe sepsis, 28 postoperative patients after major abdominal surgery, 18 healthy volunteers) were enrolled. Baseline and clinical data were evaluated. Blood samples from patients with severe sepsis were collected at the time of sepsis diagnosis, and 48 and 120 hours later; samples from healthy volunteers were collected once, and from postoperative patients, once immediately after surgery. We measured caspase-cleaved and uncleaved cytokeratin-18 (CK-18, intermediate filament protein) as a marker of cell death, isolated CK-18 fragments as a marker of apoptosis, as well as IL-6, soluble vascular cell adhesion molecule, and soluble intercellular adhesion molecule.
RESULTS: Age and sex of patients with severe sepsis and postoperative patients were comparable, whereas healthy volunteers were significantly younger. In healthy volunteers, the mode of cellular turnover was primarily apoptotic cell death. Postoperative patients showed comparable levels of apoptotic activity, but necrotic cell death was markedly increased, probably due to surgical tissue injury. In contrast, patients with severe sepsis, and especially non-survivors of the septic group showed increased levels of markers for both apoptotic and necrotic cell death. In severe septic patients with liver dysfunction, necrosis is increased relative to severe septic patients with intact hepatic function. For severe septic patients with liver dysfunction, a cut-off value for caspase-cleaved and uncleaved cytokeratin-18 could be calculated, in order to identify patients at high risk for death due to severe sepsis.
CONCLUSIONS: The measurement of caspase-cleaved and uncleaved cytokeratin-18 appears to be an early predictor for survival in severe septic patients with hepatic dysfunction. Furthermore, the loss of parenchymal cells due to necrosis may be the primary mode of cell death in these patients. This may limit possible therapeutic options.