Maneesh Dave

Hepatic Injury in Nonalcoholic Steatohepatitis Contributes to Altered Intestinal Permeability.

Background & Aims Emerging data suggest that changes in intestinal permeability and increased gut microbial translocation contribute to the inflammatory pathway involved in nonalcoholic steatohepatitis (NASH) development. Numerous studies have investigated the association between increased intestinal permeability and NASH. Our meta-analysis of this association investigates the underlying mechanism. Methods A meta-analysis was performed to compare the rates of increased intestinal permeability in patients with NASH and healthy controls. To further address the underlying mechanism of action, we studied changes in intestinal permeability in a diet-induced (methionine-and-choline-deficient; MCD) murine model of NASH. In vitro studies were also performed to investigate the effect of MCD culture medium at the cellular level on hepatocytes, Kupffer cells, and intestinal epithelial cells. Results Nonalcoholic fatty liver disease (NAFLD) patients, and in particular those with NASH, are more likely to have increased intestinal permeability compared with healthy controls. We correlate this clinical observation with in vivo data showing mice fed an MCD diet develop intestinal permeability changes after an initial phase of liver injury and tumor necrosis factor-α (TNFα) induction. In vitro studies reveal that MCD medium induces hepatic injury and TNFα production yet has no direct effect on intestinal epithelial cells. Although these data suggest a role for hepatic TNFα in altering intestinal permeability, we found that mice genetically resistant to TNFα-myosin light chain kinase (MLCK)–induced intestinal permeability changes fed an MCD diet still develop increased permeability and liver injury. Conclusions Our clinical and experimental results strengthen the association between intestinal permeability increases and NASH and also suggest that an early phase of hepatic injury and inflammation contributes to altered intestinal permeability in a fashion independent of TNFα and MLCK.

Mesenchymal stem cell therapy for inflammatory bowel disease: A systematic review and meta-analysis

Abstract:Recent advances in inflammatory bowel disease (IBD) therapeutics include novel medical, surgical, and endoscopic treatments. Among these, stem cell therapy is still in its infancy, although multiple studies suggest that the immunomodulatory effect of stem cell therapy may reduce inflammation and tissue injury in patients with IBD. This review discusses the novel avenue of stem cell therapy and its potential role in the management of ulcerative colitis and Crohns disease. We conducted a comprehensive literature search to identify studies examining the role of stem cell therapy (without conditioning and immunomodulatory regimens) in IBD. Taken together, these studies suggest a promising role for stem cell therapy in IBD although the substantial challenges, such as cost and inadequate/incomplete characterization of effect, limit their current use in clinical practice.

Autologous Mesenchymal Stem Cells, Applied in a Bioabsorbable Matrix, for Treatment of Perianal Fistulas in Patients With Crohn's Disease

In patients with Crohns disease, perianal fistulas recur frequently, causing substantial morbidity. We performed a 12-patient, 6-month, phase 1 trial to determine whether autologous mesenchymal stem cells, applied in a bioabsorbable matrix, can heal the fistula. Fistula repair was not associated with any serious adverse events related to mesenchymal stem cells or plug placement. At 6 months, 10 of 12 patients (83%) had complete clinical healing and radiographic markers of response. We found placement of mesenchymal stem cell-coated matrix fistula plugs in 12 patients with chronic perianal fistulas to be safe and lead to clinical healing and radiographic response in 10 patients. ClinicalTrials.gov Identifier: NCT01915927.

Mesenchymal stem/stromal cell therapy for inflammatory bowel disease: an updated review with maintenance of remission

Purpose of review There is a need for novel therapies for inflammatory bowel diseases (IBDs) that are well tolerated and effective. Currently, mesenchymal stem/stromal cells (MSCs) are being investigated in clinical trials for treatment of IBD. In this review, we update the recently published studies with an emphasis on the long-term efficacy of MSC therapy for IBD. Recent findings A cumulative body of data, including a recent phase III randomized controlled trial demonstrated excellent fistula healing in patients with refractory Crohns perianal fistulae treated via local injections of MSCs and with a good safety profile. Follow-up studies suggest long-term efficacy of MSC therapy for complex perianal Crohns disease fistulae; however, the efficacy decreases over time and may necessitate repeat treatment. Systemic (intravenous) therapy for luminal IBD offers a relatively well tolerated alternative but its efficacy remains unclear. Summary Recent studies demonstrate that MSCs are well tolerated and have an excellent short-term efficacy for the management of refractory fistulizing perianal Crohns disease. The current data suggest that its influence may ‘wear off’ over time. More data on larger number of patients with longer duration of follow-up in the setting of a randomized placebo controlled trial are needed to confirm these promising results. For luminal IBD, there is a need for more mechanistic studies in representative preclinical murine models, and the results of an ongoing phase III randomized controlled trial are eagerly awaited.

Protective Role for TWEAK/Fn14 in Regulating Acute Intestinal Inflammation and Colitis-Associated Tumorigenesis

Inflammatory bowel disease causes chronic, relapsing intestinal inflammation that can lead to the development of colorectal cancer. Members of the TNF superfamily are key regulators of intestinal inflammation. In particular, TNF-like weak inducer of apoptosis (TWEAK) and its receptor, Fn14, are involved in normal and pathologic intestinal tissue remodeling. In this study, we show that the TWEAK/Fn14 signaling complex plays a protective role during the acute stage of intestinal inflammation and contributes to the prevention of colitis-associated cancer during chronic inflammation through its proapoptotic effects. Colitis was induced in Fn14-/- and Fn14+/+ wild-type littermates by administering 3% dextran sodium sulfate (DSS) for 7 days followed by 2-week recovery; azoxymethane (AOM) administration followed by two cycles of DSS/recovery was used to induce tumors. Reciprocal bone marrow chimeric mice were generated to compare hematopoietic and nonhematopoietic-specific effector tissues. Fn14-/- mice had enhanced susceptibility to colitis compared with Fn14+/+ controls as assessed by endoscopic and histologic inflammatory scores, daily weight loss, and mortality rates during recovery after DSS administration. Bone marrow transfer experiments showed that both hematopoietic and nonhematopoietic components are involved in protection against colitis. Tumor lesions were found in the colons of most Fn14-/- mice, but not Fn14+/+ controls. AOM/DSS administration enhanced susceptibility to tumorigenesis in Fn14-/- mice. Overall, these findings show that Fn14 plays a protective role during the acute stages of intestinal inflammation, and its absence promotes the development of colitis-associated cancer. Cancer Res; 76(22); 6533-42. ©2016 AACR.

No risk of malignancy with biologics in inflammatory bowel disease: is the debate over?

infections was to limit treatment to patients with advanced liver fibrosis and to treat with a combination of pegylated interferon plus RBV Presently, the second-generation DAAs cause fewer adverse events and provide higher efficacy than pegylated interferon plus RBV. Furthermore, the secondgeneration DAAs do not interact with other drugs. However, it is unclear whether reversal of liver fibrosis after the eradication of HCV infection is a reality. Calvaruso et al performed computer-assisted digital image analyses of histologic liver sections of samples from recipients of HCV-positive LT patients. They demonstrated that the proportion of liver collagen areas correlated with the severity of portal hypertension (J Gastroenterol Hepatol 2012;27: 1227–1232). Furthermore, Kim et al demonstrated that the clinical stage and grade of portal hypertension were correlated strictly with the Laennec fibrosis score (J Hepatol 2011;55:1004–1009). Patients with thin fibrotic septa associatedwith largenodules probably have a formof liverfibrosis that can regress after an efficacious antiviral treatment versus patients with broad fibrotic septa associated with small nodules. These histologic conditions are completely different. In the latter condition, regression of fibrosis after a sustained virologic response is not the norm.We studied a population of patients with very advanced liver cirrhosis who showed benefit in terms of viral eradication, but not for complications related to cirrhosis andsurvival. Atpresent, it is notpossible to accept that patientswith LTandHCV infection coulddie owing to a complication of liver cirrhosis after viral eradication. Cicero, in the process of defending Sextus Roscius, who was accused of patricide, declared “Cui Bono?” (Who benefits?). This is the question that, in the era of second-generationDAAs, we are obligated to answer.

Understanding the Cautions and Contraindications of Immunomodulator and Biologic Therapies for Use in Inflammatory Bowel Disease

Abstract: Ulcerative colitis and Crohns disease are chronic inflammatory bowel diseases for which there are no cures. These diseases are immunopathogenic, and medical treatment is centered on the temperance of a dysregulated immune response to allow mucosal healing and prevent the sequelae of fistulation and stenosis. Accordingly, the armamentarium of medications, which has expanded immensely in recent history, is not without significant infectious and neoplastic risks. Many of these untoward effects can be mitigated by screening and avoidance of contraindicated medications. This review seeks to highlight the cautions for use of immunomodulators, anticytokine, and &agr;4-integrin antagonists. The potential adverse events are further complicated by substantial heterogeneity in disease phenotype in the inflammatory bowel disease population. Large patient registries and databases provide considerable experience and knowledge to calculate the incidence of safety outcomes. To identify rarer outcomes after prolonged therapy, more prospective studies and continued adverse event reporting will aid safe application and minimize potential harms.

In-patient outcomes of Hematopoietic Stem Cell Transplantation in Patients with Immune Mediated Inflammatory Diseases: A Nationwide Study

The impact of underlying immune-mediated inflammatory diseases (IMID) in patients undergoing hematopoietic stem cell transplant (HSCT) is unclear. Hematopoietic cell transplantation co-morbidity index (HCT-CI) is gaining acceptance as a reliable clinical method to score pre-transplant co-morbidities. Higher HCT-CI from a co-morbid IMID implies higher NRM. However, HCT-CI integrates many IMIDs with different pathogenesis and treatment together which may lead to spurious results. We performed a cross-sectional study using Nationwide Inpatient Sample dataset from 1998 to 2011 to compare the outcomes of HSCT in patients with different co-morbid IMIDs with patients without any co-morbid IMIDs. In both our multivariate and stringent matched-pair analysis, ulcerative colitis (UC) was associated with increased mortality while rheumatoid arthritis and psoriasis were associated with lower mortality as compared to no IMID group. Furthermore, in allogeneic HSCT subgroup, UC was associated with higher mortality and psoriasis was associated with lower mortality. In conclusion, we found that depending on the type of HSCT, each IMID has a different impact on outcomes of HSCT. Furthermore, UC patients had increased mortality if they had primary sclerosing cholangitis and had a higher risk of opportunistic infections like tuberculosis and cytomegalovirus suggesting the need for increased vigilance in this cohort.

Loss of Response to Anti-Tumor Necrosis Factor Alpha Therapy in Crohn’s Disease Is Not Associated with Emergence of Novel Inflammatory Pathways

BackgroundWhile monoclonal antibodies against tumor necrosis factor-α (TNFα) are effective in treating Crohn’s disease (CD), approximately one-third of patients lose response. The mechanisms underlying this loss of response remain elusive.AimWe sought to determine if novel biological pathways, including TNFα-independent inflammatory pathways, emerge in those with loss of response to anti-TNFα.MethodsUsing RNA microarray technology in 28 patients with CD, we examined the colonic gene expression differences between those with active inflammation in the setting of loss of response to TNFα-antagonist therapy (“loss of responders”) compared to anti-TNFα naïve patients with active inflammation and those on anti-TNF therapy in disease remission. Pathway enrichment analyses were performed.ResultsWe found that colonic expression of chemokines known to drive inflammation (CXCL20, CXCL9, and CXCL10) was elevated in those with loss of response compared to those in remission. Expression of genes critical to modulating oxidative stress burden (DUOX2, DUOXA2, and NOS2) was also elevated. Additionally, MMP3, MMP1, and MMP12 were elevated in those with continued inflammation. Gene enrichment analysis revealed that loss of responders exhibited dysregulation in the cysteine and methionine metabolism pathway, suggesting alteration in oxidative stress burden. There were no differences in genes or pathways between loss of responders and those who were TNFα-naïve. However, loss of response occurred despite the ability of anti-TNFα therapy to normalize APO gene expression.ConclusionOur analyses suggest that loss of response to anti-TNFα is not driven by the emergence of pathways that bypass the action or induce resistance to anti-TNFα therapy.

Ultrasound-guided intracardiac injection of human mesenchymal stem cells to increase homing to the intestine for use in murine models of experimental inflammatory bowel diseases

Crohns disease (CD) is a common chronic inflammatory disease of the small and large intestines. Murine and human mesenchymal stem cells (MSCs) have immunosuppressive potential and have been shown to suppress inflammation in mouse models of intestinal inflammation, even though the route of administration can limit their homing and effectiveness 1,3,4,5. Local application of MSCs to colonic injury models has shown greater efficacy at ameliorating inflammation in the colon. However, there is paucity of data on techniques to enhance the localization of human bone marrow-derived MSCs (hMSCs) to the small intestine, the site of inflammation in the SAMP-1/YitFc (SAMP) model of experimental Crohns disease. This work describes a novel technique for the ultrasound-guided intracardiac injection of hMSCs in SAMP mice, a well-characterized spontaneous model of chronic intestinal inflammation. Sex- and age-matched, inflammation-free AKR/J (AKR) mice were used as controls. To analyze the biodistribution and the localization, hMSCs were transduced with a lentivirus containing a triple reporter. The triple reporter consisted of firefly luciferase (fl), for bioluminescent imaging; monomeric red fluorescent protein (mrfp), for cell sorting; and truncated herpes simplex virus thymidine kinase (ttk), for positron emission tomography (PET) imaging. The results of this study show that 24 h after the intracardiac administration, hMSCs localize in the small intestine of SAMP mice as opposed to inflammation-free AKR mice. This novel, ultrasound-guided injection of hMSCs in the left ventricle of SAMP mice ensures a high success rate of cell delivery, allowing for the rapid recovery of mice with minimal morbidity and mortality. This technique could be a useful method for the enhanced localization of MSCs in other models of small-intestinal inflammation, such as TNFΔRE6. Future studies will determine if the increased localization of hMSCs by intra-arterial delivery can lead to increased therapeutic efficacy.