Cost-Effectiveness and Budget Impact Analyses of Selective Internal Radiation Therapy versus Atezolizumab Plus Bevacizumab from a German Statutory Health Insurance Perspective.

Purpose: To compare personalized dosimetry with yttrium-90 (90Y)-loaded glass microspheres (SIRT) vs atezolizumab and bevacizumab (A+B) in hepatocellular carcinoma (HCC) treatment in terms of cost-effectiveness and budget impact from a German statutory health insurance (SHI) perspective. Patients and Methods: Cost-effectiveness analysis (CEA) and budget impact analysis (BIA) models were developed in MS Excel. The available key studies (IMbrave150 and DOSISPHERE-01) suggest that both strategies are comparable in terms of progression-free survival and overall survival in HCC, but a difference in severe adverse events (SAE) in favor of SIRT was observed. Accordingly, the CEA model investigates the endpoints "cost per SAE avoided" and "cost per quality-adjusted life year (QALY) gained", whereas the BIA simulates the impact of a stepwise re-allocation of current market share to the option which emerges as more cost-effective from the CEA. Results: The model suite estimated a mean annual total per-patient costs of € 29,984 for SIRT, compared to € 75,725 for A+B. SIRT was associated with a lower number of SAE and a higher number of QALYs compared to A+B. Switching additionally 25% of the eligible patients (≈500) from systemic therapy to SIRT could generate annual savings of approximately € 22.6 million Euros to the SHI. Conclusion: SIRT was identified as dominant treatment strategy. SIRT use not only saves SHI expenditure compared to systemic immunotherapy but also yields extra QALYs. This positions SIRT as the dominant and more cost-effective treatment strategy for patients with HCC. The savings to the SHI system, derived from the BIA conducted, become increasingly significant with rising adoption rates of SIRT.

Is there a place for sigmoidoscopy in colorectal cancer screening? A systematic review and critical appraisal of cost-effectiveness models.

INTRODUCTION: Screening for colorectal cancer (CRC) is effective in reducing both incidence and mortality. Colonoscopy and stool tests are most frequently used for this purpose. Sigmoidoscopy is an alternative screening measure with a strong evidence base. Due to its distinct characteristics, it might be preferred by subgroups. The aim of this systematic review is to analyze the cost-effectiveness of sigmoidoscopy for CRC screening compared to other screening methods and to identify influencing parameters. METHODS: A systematic literature search for the time frame 01/2010-01/2023 was conducted using the databases MEDLINE, Embase, EconLit, Web of Science, NHS EED, as well as the Cost-Effectiveness Registry. Full economic analyses examining sigmoidoscopy as a screening measure for the general population at average risk for CRC were included. Incremental cost-effectiveness ratios were calculated. All included studies were critically assessed based on a questionnaire for modelling studies. RESULTS: Twenty-five studies are included in the review. Compared to no screening, sigmoidoscopy is a cost-effective screening strategy for CRC. When modelled as a single measure strategy, sigmoidoscopy is mostly dominated by colonoscopy or modern stool tests. When combined with annual stool testing, sigmoidoscopy in 5-year intervals is more effective and less costly than the respective strategies alone. The results of the studies are influenced by varying assumptions on adherence, costs, and test characteristics. CONCLUSION: The combination of sigmoidoscopy and stool testing represents a cost-effective screening strategy that has not received much attention in current guidelines. Further research is needed that goes beyond a narrow focus on screening technology and models different, preference-based participation behavior in subgroups.

Lifestyle interventions for patients with non-alcoholic steato-hepatitis-Design, rationale and protocol of the study "target group-specific optimisation of lifestyle interventions for behavior change in non-alcoholic steato-hepatitis (OPTI-NASH)".

BACKGROUND: Non-alcoholic steato-hepatitis (NASH) is the inflammatory, progressive form of non-alcoholic fatty liver disease (NAFLD). A delayed diagnose interval is typical for the majority of the patients because of the asymptomatic natural course. However, serious sequelae may develop such as cirrhosis or hepatocellular carcinoma. NASH is also associated with an increased risk of metabolic diseases. Obesity developed due to a lack of exercise or a disadvantageous diet often leads to NAFLD or NASH, thereby interventions including enhanced physical activity and calorie reduction form the actual gold standard of treatment. To date, patients rarely use these. The project aims to model lifestyle interventions based on the preferences of the NASH patients. METHODS: Based on a systematic review and focus group discussions, two discrete choice experiments (DCE) will be designed, one on aspects influencing successful uptake of lifestyle interventions and one to analyses parameters contributing to long-term participation. An online survey will be used to elicit patient's preferences on program design and on motivational aspects in a cross-sectional design. The recruitment will take place in nine certified specialist practices and hospital outpatient clinics aiming to reach a sample size of n = 500 which is also required for the DCE design. DISCUSSION: The results will provide an overview of the NASH patient's preferences regarding the successful uptake and long-term implementation of lifestyle interventions. Recommendations for optimized lifestyle change programs will be derived and an intervention manual will be developed to facilitate target group-specific inclusion in programs in practice.

Real-world experience for the outcomes and costs of treating hepatitis C patients: Results from the German Hepatitis C-Registry (DHC-R).

BACKGROUND & AIMS: With long-term consequences like the development of liver cirrhosis and hepatocellular carcinoma, chronic hepatitis C virus (HCV) infection is associated with a significant health burden. Information on HCV treatment outcomes and costs in routine care is still rare, especially for subgroups. The aim of this study was to analyse the treatment outcomes and costs of subgroups in routine care and to compare them over time with previous analyses. METHODS: Data were derived from a noninterventional study including a subset of 10298 patients receiving DAAs with genotypes 1 and 3. Sociodemographic, clinical parameters and costs were collected using a web-based data recording system. The total sample was subdivided according to treatment regimen, cirrhosis status as well as present HIV infection and opioid substitution treatment (OST). RESULTS: 95% of all patients achieved SVR. Currently used DAA showed higher SVR-rates and less adverse events (AE) compared to former treatments. Concerning subgroups, cirrhotic patients, HIV-coinfected patients and OST patients showed lower but still high SVR-rates. In comparison, cirrhotic had considerably longer treatment duration and more frequent (serious) AE. Overall, average treatment costs were €48470 and costs per SVR were €51129; for currently used DAAs costs amounted to €30330 and costs per SVR to €31692. After the end of treatment, physical health is similar to the general population in all patients except cirrhotic. Mental health remains far behind in all subgroups, even for currently used DAA. CONCLUSIONS: Over time, some relevant factors developed positively (SVR-rates, costs, treatment duration, adverse events, health-related quality of life (HRQoL)). Further research on HRQoL, especially on mental health, is necessary to evaluate the differences between subgroups and HRQoL over time and to identify influencing factors.

Non-Invasive Reliable Methods to Objectify the Positive Influence of Hepatitis C Virus Treatment on Liver Stiffness.

BACKGROUND: Chronic active hepatitis C virus (HCV) infection is a major public health problem and causes liver fibrosis (LF) up to liver cirrhosis (LC). LF can be estimated by non-invasive, easy handling methods. With implementation of new HCV therapies, elimination rates of HCV are near 100%, resulting in less clinical complications and costs. The aim of our study was to evaluate the positive influence of HCV treatment on liver stiffness by non-invasive assessments of LF. METHODS: Sixty-two patients with HCV were treated with antiviral drug regimes. Serological fibrosis scores and ultrasound elastography (acoustic radiation force impulse and shear wave elasticity imaging (ARFI-SWEI)) were used for LF assessment on day 0 and 6 months after therapy. RESULTS: Antiviral treatment was successful in all cases. ARFI-SWEI measurements showed an improvement of all LF stages. Results of serological markers and scores were heterogeneous. Significant positive effects of treatment were seen for aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 (FIB-4) scores, only. Further Pearson's coefficient showed moderate till very high correlations for ARFI-SWEI and FIB-4/APRI scores. CONCLUSION: Today HCV therapy is able to cure HCV. Positive influences are improvement of LF stages. ARFI-SWEI, APRI and FIB-4 score are useful, easy handling tools to verify positive influence of HCV treatment on LF alone or in combination.

Elimination of hepatitis C virus in Germany: modelling the cost-effectiveness of HCV screening strategies.

BACKGROUND: Chronic hepatitis C is a major public health burden. With new interferon-free direct-acting agents (showing sustained viral response rates of more than 98%), elimination of HCV seems feasible for the first time. However, as HCV infection often remains undiagnosed, screening is crucial for improving health outcomes of HCV-patients. Our aim was to assess the long-term cost-effectiveness of a nationwide screening strategy in Germany. METHODS: We used a Markov cohort model to simulate disease progression and examine long-term population outcomes, HCV associated costs and cost-effectiveness of HCV screening. The model divides the total population into three subpopulations: general population (GEP), people who inject drugs (PWID) and HIV-infected men who have sex with men (MSM), with total infection numbers being highest in GEP, but new infections occurring only in PWIDs and MSM. The model compares four alternative screening strategies (no/basic/advanced/total screening) differing in participation and treatment rates. RESULTS: Total number of HCV-infected patients declined from 275,000 in 2015 to between 125,000 (no screening) and 14,000 (total screening) in 2040. Similarly, lost quality adjusted life years (QALYs) were 320,000 QALYs lower, while costs were 2.4 billion EUR higher in total screening compared to no screening. While incremental cost-effectiveness ratio (ICER) increased sharply in GEP and MSM with more comprehensive strategies (30,000 EUR per QALY for total vs. advanced screening), ICER decreased in PWIDs (30 EUR per QALY for total vs. advanced screening). CONCLUSIONS: Screening is key to have an efficient decline of the HCV-infected population in Germany. Recommendation for an overall population screening is to screen the total PWID subpopulation, and to apply less comprehensive advanced screening for MSM and GEP.

Outcomes and costs of treating hepatitis C patients with second-generation direct-acting antivirals: results from the German Hepatitis C-Registry.

OBJECTIVE: Chronic hepatitis C virus infection is associated with a significant health burden. Long-term consequences are the development of liver cirrhosis and hepatocellular carcinoma. The introduction of direct-acting antivirals (DAA) has led to an increase in sustained virologic response rates (SVR), but is accompanied by higher treatment costs. The aim of this study was to assess the outcomes and costs of treating hepatitis C virus infected patients with DAAs in clinical practice in Germany. PATIENTS AND METHODS: Data were derived from a noninterventional study including a pharmacoeconomic subset of 2673 patients with genotypes 1 and 3 who initiated and completed treatment between February 2014 and February 2017. Sociodemographic and clinical parameters as well as resource utilization were collected using a web-based data recording system. Costs were calculated using official remuneration schemes. RESULTS: The mean age of the patients was 54.6 years; 48% were men. 93.5% of all patients achieved an SVR. The average total treatment costs were &OV0556;67 979 (&OV0556;67 131 medication costs, &OV0556;824 ambulatory care, &OV0556;24 hospital costs). The average costs per SVR of &OV0556;72 705 were calculated. Differences in SVR and costs according to genotype, treatment regimen, treatment experience, and cirrhosis were observed. Quality-of-life data showed no or a minimal decrease during treatment. CONCLUSION: This analysis confirms high SVR rates for newly introduced DAAs in a real-world setting. Costs per SVR estimated are comparable to first-generation DAA. Given the fact that the costs for the currently used treatment regimens have declined, it can be assumed that the costs per SVR have also decreased. Our insight into real-world outcomes and costs can serve as a basis for a comparison with the mentioned newly introduced treatment regimens.

Cost-Effectiveness of Treating Hepatitis C with Sofosbuvir/Ledipasvir in Germany.

BACKGROUND: Infections with the hepatitis C virus (HCV) are a global public health problem. Long-term consequences are the development of liver cirrhosis and hepatocellular carcinoma. Newly introduced direct acting antivirals, especially interferon-free regimens, have improved rates of sustained viral response above 90% in most patient groups and allow treating patients who were ineligible for treatment in the past. These new regimens have replaced former treatment and are recommended by current guidelines. However, there is an ongoing discussion on high pharmaceutical prices. Our aim was to assess the long-term cost-effectiveness of treating hepatitis C genotype 1 patients with sofosbuvir/ledipasvir (SOF/LDV) treatment in Germany. MATERIAL AND METHODS: We used a Markov cohort model to simulate disease progression and assess cost-effectiveness. The model calculates lifetime costs and outcomes (quality-adjusted life years, QALYs) of SOF/LDV and other strategies. Patients were stratified by treatment status (treatment-naive and treatment-experienced) and absence/presence of cirrhosis. Different treatment strategies were compared to prior standard of care. Sensitivity analyses were performed to evaluate model robustness. RESULTS: Base-case analyses results show that in treatment-naive non-cirrhotic patients treatment with SOF/LDV dominates the prior standard of care (is more effective and less costly). In cirrhotic patients an incremental cost-effectiveness ratio (ICER) of 3,383 €/QALY was estimated. In treatment-experienced patients ICERs were 26,426 €/QALY and 1,397 €/QALY for treatment-naive and treatment-experienced patients, respectively. Robustness of results was confirmed in sensitivity analyses. CONCLUSIONS: Our analysis shows that treatment with SOF/LDV is cost-effective compared to prior standard of care in all patient groups considering international costs per QALY thresholds.

Ultrasound Elastography Used for Preventive Non-Invasive Screening in Early Detection of Liver Fibrosis.

BACKGROUND: Early discovery of liver fibrosis is becoming more popular because of enhanced incidence of hepatocellular carcinoma. Ultrasound-based liver elastography is a method used to approve suspected liver fibrosis or cirrhosis. We assessed the clinical usefulness of acoustic radiation force impulse shear wave elasticity imaging (ARFI-SWEI) as a preventive screening method to uncover fibrosis. METHODS: We screened 382 patients by native routine sonography for abnormal liver results and divided them into six groups: group 1: normal liver, groups 2-4: fatty liver grade I-III, group 5: liver cirrhosis, and group 6: inhomogenic liver tissue. Then ARFI-SWEI was performed and the results were compared with published shear wave velocity cut-off values that were predictive of each fibrosis stage (F0-4). A control group consisted of 20 healthy volunteers. RESULTS: The part of liver fibrosis ≥ F2 was in groups 1-4: 20-32%, group 5: 100%, and group 6: 91%. Main causes for fibrosis stage ≥ F2 were (non)-alcoholic steatohepatitis, chronic viral or autoimmune hepatitis and chronic heart failure. CONCLUSIONS: Screening of the liver tissue in b-mode ultrasound can underestimate possible liver fibrosis; by using ARFI-SWEI, liver fibrosis can be uncovered early. It is a suitable preventive method comparable to colonoscopy for colon cancer.

Outcomes, costs and cost-effectiveness of treating hepatitis C with direct acting antivirals.

Hepatitis C is a global public health burden. Long-term consequences are the development of liver cirrhosis and hepatocellular carcinoma. Introduction of different direct acting antivirals targeting the hepatitis C proteins has considerably increased rates of sustained viral response. First active substances introduced in 2011 were NS3/4A protease inhibitors telaprevir and boceprevir. In 2013/2014 the second generation of direct acting antivirals sofosbuvir, simeprevir, daclatasvir, ledipasvir and 3D therapy containing ombitasvir/paritaprevir/ritonavir and dasabuvir followed. This review focuses on treatment outcomes and costs of introduced direct acting antivirals. We provide an overview on SVR-rates in clinical trials and clinical practice, treatment costs in different countries as well as results of cost-effectiveness analyses for different treatment strategies.

[Rare cause of recurrent subileus]. / Seltene Genese eines rezidivierenden Subileus.

HISTORY AND CLINICAL FINDINGS: An 85-years-old woman with percutaneous endoscopic gastrostomy (PEG) presented at our emergency unit with repeating abdominal pain and changes in the consistency of the stool. The PEG was placed during a treatment of an oropharynxcarcinoma in the past, was replaced repeatedly and is still in use. INVESTIGATIONS: The initial clinical results were unobtrusive; the ultrasound of the abdomen showed mild distended loops of the small intestine, the x-ray of the abdomen was unsuspicious with diagnosis of subileus by constipation. The esophagogastroduodenoscopy was also without pathological findings and showed correct position of the PEG and normal aspect of the gastric tissue. An additional computerized tomography (ct-scan) of the abdomen demonstrated a foreign body nearly 2.5 cm in diameter in the distal part of the small intestine, the terminal ileum, differentiated as PEG retaining plate, also seen retrospectively in the initial x-ray. TREATMENT AND COURSE: Because the endoscopic salvage failed, the foreign body had to be removed surgically. The retaining plate was the cause for subtotal occlusion and also for the perforation of the small intestine. It was found nearly 15 cm before ileo-terminal valve. After operation the patient recovered soon. CONCLUSION: The history gave no hints of accidentally broken PEG-tube; presumably the retaining plate was cut off while the PEG was changed and let go on natural way. The aim of gastroenterologists should be removing PEG under endoscopic control.

Cost of treating hepatitis C in Germany: a retrospective multicenter analysis.

BACKGROUND: Viral hepatitis is major a public health problem affecting millions of people worldwide. Estimates assume 400 000-500 000 people chronically infected with hepatitis C virus (HCV) in Germany. Long-term consequences are the development of liver cirrhosis and hepatocellular carcinoma. The aim of the study was to assess the costs for treating patients with chronic HCV in Germany. METHODS: We conducted a retrospective multicenter observational study. The design was approved by an ethics committee, and patients were asked for their informed consent. Patients were grouped in four different health states. Healthcare utilization data were extracted from doctor files of six medical centers in Germany. RESULTS: Data of 315 patients with chronic HCV were analyzed. The mean age was 49.4 years, 57.5% were male and 67.9% had a genotype 1 infection. The most common routes of transmission were injection drug use (39.0%) and infection through blood products (15.9%). The average total cost was €19 147 including ambulatory care and diagnostics (€1686), pharmaceuticals (€14 875), inpatient care (€1293), and sick leave (€1293). For patients in stable health states (mild and moderate HCV, compensated cirrhosis), costs did not differ significantly and were mainly influenced by antiviral treatment. For patients with decompensated cirrhosis, inpatient care accounted for the largest part of the costs. CONCLUSION: Treatment of HCV patients involves high costs, mainly associated with the length of antiviral therapy. Viral eradication can prevent severe disease stages, which are associated with high costs. It is necessary to follow current guidelines and monitor patients closely to avoid unnecessary costs.

Cost-effectiveness of Triple Therapy with Telaprevir for Chronic Hepatitis C Virus Patients in Germany.

Background: About 400,000-500,000 people are infected with hepatitis C in Germany. Long-term consequences are the development of liver cirrhosis and hepatocellular carcinoma. The introduction of first generation protease inhibitors has significantly improved the treatment of hepatitis C genotype 1 patients. The aim of the study was to assess the cost-effectiveness of triple therapy with telaprevir in Germany. Methods: We used a Markov model on disease progression and natural history to assess the cost-effectiveness of triple therapy with telaprevir compared to standard treatment with pegylated interferon and ribavirin. Model structure and inputs were discussed with clinical experts. Deterministic and probabilistic sensitivity analyses were performed to verify the robustness of results. Results: The base-case analyses shows that triple therapy results in higher costs (untreated patients: €48,446 vs. €30,691; previously treated patients: €63,228 vs. €48,603) and better outcomes (untreated patients: 16.85 qualily of life years [QALYs] vs. 15.97 QALYs; previously treated patients: 14.16 QALYs vs. 12.89 QALYs). The incremental cost-effectiveness ratio (ICER) was €20,131 per QALY and €30,567 per life year gained (LYG) for previously untreated patients. ICER in treatment experienced patients was €7,664 per QALY for relapse patients, €12,506 per QALY for partial responders and €28,429 per QALY for null responders. Results were robust in sensitivity analyses. Conclusion: Although triple therapy with telaprevir leads to additional costs, there is a high probability of being cost-effective for different thresholds. This health economic analysis makes an important contribution to current debates on cost savings and efficient resource allocation in the German healthcare sector.

Identification of PSME3 as a novel serum tumor marker for colorectal cancer by combining two-dimensional polyacrylamide gel electrophoresis with a strictly mass spectrometry-based approach for data analysis.

The purpose of this study was to identify and validate novel serological protein biomarkers of human colorectal cancer (CRC). Proteins from matched CRC and adjacent normal tissue samples were resolved by two-dimensional gel electrophoresis. From each gel all spots were excised, and enveloped proteins were identified by MS. By comparison of the resulting protein profiles, dysregulated proteins can be identified. A list of all identified proteins and validation of five exemplarily selected proteins, elevated in CRC was reported previously (Roessler, M., Rollinger, W., Palme, S., Hagmann, M. L., Berndt, P., Engel, A. M., Schneidinger, B., Pfeffer, M., Andres, H., Karl, J., Bodenmuller, H., Ruschoff, J., Henkel, T., Rohr, G., Rossol, S., Rosch, W., Langen, H., Zolg, W., and Tacke, M. (2005) Identification of nicotinamide N-methyltransferase as a novel serum tumor marker for colorectal cancer. Clin. Cancer Res. 11, 6550-6557). Here we describe identification and initial validation of another potential marker protein for CRC. Comparison of tissue protein profiles revealed strong elevation of proteasome activator complex subunit 3 (PSME3) expression in CRC tissue. This dysregulation was not detectable based on the spot pattern. The PSME3-containing spot on tumor gels showed no visible difference to the corresponding spot on matched control gels. MS analysis revealed the presence of two proteins, PSME3 and annexin 4 (ANXA4) in one and the same spot on tumor gels, whereas the matched spot contained only one protein, ANXA4, on control gels. Therefore, dysregulation of PSME3 was masked by ANXA4 and could only be recognized by MS-based analysis but not by image analysis. To validate this finding, antibody to PSME3 was developed, and up-regulation in CRC was confirmed by Western blot analysis and immunohistochemistry. Finally by developing a highly sensitive immunoassay, PSME3 could be detected in human sera and was significantly elevated in CRC patients compared with healthy donors and patients with benign bowel disease. We propose that PSME3 be considered a novel serum tumor marker for CRC that may have significance in the detection and in the management of patients with this disease. Further studies are needed to fully assess the potential clinical value of this marker candidate.

Identification of nicotinamide N-methyltransferase as a novel serum tumor marker for colorectal cancer.

PURPOSE: The goal of this study was to identify and validate novel serum markers of human colorectal cancer as potential candidates for noninvasive detection of early colorectal neoplasm. EXPERIMENTAL DESIGN: Employing two-dimensional gel electrophoresis and mass spectrometry, we analyzed 16 matched colorectal cancer and adjacent normal tissue samples. Proteins found to be elevated in cancer tissue were further validated by generating antibodies which were used for immunoblotting of tissue samples and for the development of highly sensitive immunoassays for assessment of serum samples. RESULTS: In total, 735 different proteins were identified in colon tissue. Strong elevation in colorectal cancer for five proteins was confirmed by immunoblot analysis: transforming growth factor-beta induced protein ig-h3 (betaIG-H3), nicotinamide N-methyltransferase (NNMT), nucleoside diphosphate kinase A (nm23-H1), purine nucleoside phosphorylase (PNPH), and mannose-6-phosphate receptor binding protein 1 (M6P1). Elevated levels of NNMT, which is not predicted to be secreted but is known as a cytoplasmic protein, were found in serum from patients with colorectal cancer. Employing a receiver-operating characteristic curve based on the measurement of 109 patients with colorectal cancer and 317 healthy controls, we obtained an area under the curve of 0.84 for NNMT, which was superior to the established tumor marker carcinoembryogenic antigen with an area under the curve of 0.78. CONCLUSIONS: It is proposed that NNMT serum levels may have significance in the early detection and in the management of patients with colorectal cancer.

Responsiveness of intestinal epithelial cell lines to lipopolysaccharide is correlated with Toll-like receptor 4 but not Toll-like receptor 2 or CD14 expression.

BACKGROUND AND AIMS: Luminal bacteria have been implicated in the pathogenesis of inflammatory bowel diseases. Exposure of intestinal epithelial cells (IEC) to bacterial components potentially initiates intestinal inflammation by release of chemokines and recruitment of inflammatory cells. We analyzed receptor expression and signaling pathways involved in activation of human primary IEC and carcinoma-derived cell lines by lipopolysaccharide (LPS). MATERIALS AND METHODS: HT-29/p, HT-29/MTX, and Caco-2 cells were stimulated by LPS. IL-8 content in supernatants was analyzed by ELISA, and expression of CD14, Toll-like receptor (TLR) 2 and TLR 4 was determined by RT-PCR. Presence of TLR 4 protein was assessed by western blot analysis. LPS response was modulated by sCD14, LPS-binding protein, neutralization of CD14, and inhibitors of early signal activation. RESULTS: LPS dose-dependently induced secretion of IL-8 in undifferentiated HT-29/p cells while Caco-2 and permanently differentiated HT-29/MTX cells were unresponsive. Differently to HT-29/MTX, both HT-29/p and Caco-2 cells constitutively expressed transcripts for CD14. However, CD14 was not required for LPS-mediated induction of IL-8 in HT-29/p cells since neutralizing anti-CD14 antibodies left IL-8 levels unchanged. Unresponsiveness of Caco-2 and HT-29/MTX cells to LPS persisted in the presence of sCD14 and/or LPS-binding protein. Neither cell line expressed TLR 2 transcripts while only responsive HT-29/p cells expressed TLR 4 mRNA and TLR 4 protein. Butyrate down-regulated TLR 4 expression and significantly diminished LPS-dependent IL-8 secretion. Inhibition of G protein dependent kinase activation reduced IL-8 levels to 50%; the phosphatidyl-inositol-3'-kinase inhibitor LY294002 abrogated the response. CONCLUSION: Responsiveness of IEC lines to LPS is positively correlated with TLR 4 expression. Strategies targeting TLR 4 expression or TLR 4 mediated signaling may antagonize IEC activation by LPS.

Enhanced production of IL-18 in butyrate-treated intestinal epithelium by stimulation of the proximal promoter region.

Expression of IL-18 in intestinal epithelial cells (IEC) has been implicated in Th1 cell-mediated chronic intestinal inflammation and anti-tumor immunity. However, physiological regulatory factors have not been identified. Besides their effects on proliferation and restitution, immunomodulatory functions have been attributed to short chain fatty acids (SCFA). We investigated the effect of SCFA (butyrate, propionate, acetate) on expression of IL-18 in IEC in vitro and in vivo. Expression of IL-18 mRNA and protein in human carcinoma-derived HT-29 and Caco-2 cells was analyzed by reverse transcription-PCR and Western blot. Transcriptional regulation of IL-18 gene expression was determined by transient transfection of wild-type and mutated IL-18 promoter. Further, in vivo expression of IL-18 in the intestine from butyrate-treated and untreated mice was assessed by immunohistochemistry. IL-18 mRNA and the IL-18 protein were expressed in IEC, while IL-18 secretion was not observed. Butyrate and acetate increased intracellular IL-18 content in a time- and dose-dependent fashion. In contrast to proinflammatory stimuli butyrate potently activated the IL-18 promoter, indicating that IL-18 is regulated at the transcriptional level by SCFA. Furthermore, a 108-bp sequence in the proximal region was identified to be essential for IL-18 promoter activation by butyrate. As proof of principle butyrate effects were confirmed in vivo by demonstration of increased IL-18 protein expression in IEC from butyrate-treated mice. In conclusion, SCFA up-regulate IL-18 protein expression in IEC, suggesting a potential regulatory contribution of these luminal constituents to T cell mediated inflammatory and neoplastic intestinal conditions.