Ashwin Dhanda

Basiliximab Does Not Increase Efficacy of Corticosteroids in Patients With Steroid-Refractory Ulcerative Colitis

BACKGROUND & AIMS Basiliximab is a chimeric monoclonal antibody that binds CD25 and thereby inhibits interleukin (IL)-2-mediated proliferation of lymphocytes. IL-2 might contribute to the resistance of T cells to corticosteroids. We investigated the efficacy and safety of basiliximab as a corticosteroid-sensitizing agent in patients with corticosteroid-refractory ulcerative colitis (UC). METHODS We studied 149 patients with moderate to severe UC (Mayo score ≥6 and endoscopic subscore ≥2) despite treatment for at least 14 days with oral prednisone (40-50 mg/day). Subjects were randomly assigned to groups that were given 20 mg (n = 46) or 40 mg (n = 52) basiliximab or placebo (n = 51) at weeks 0, 2, and 4. All subjects received 30 mg/day prednisone through week 2; the dose was reduced by 5 mg each week to 20 mg/day, which was maintained until week 8. At week 8, we compared the rates of clinical remission (Mayo score ≤2, no subscore >1) for patients given basiliximab with the rate for patients given placebo. RESULTS Twenty-eight percent of patients given placebo, 29% of those given the 40-mg dose of basiliximab, and 26% of those given the 20-mg dose of basiliximab achieved clinical remission (P = 1.00 vs placebo for each dose). Basiliximab was generally well tolerated. Six subjects who received basiliximab had serious adverse events (6.1%) compared with 2 who received placebo (3.9%; P = .72). In subjects given basiliximab, incomplete saturation of CD25 (<50%) on peripheral T cells was associated with the presence of anti-basiliximab antibodies (odds ratio, 21; 95% confidence interval, 2.4-184). CONCLUSIONS Basiliximab does not increase the effect of corticosteroids in the induction of remission in outpatients with corticosteroid-resistant moderate to severe UC.

Glucocorticoid-resistant Th17 cells are selectively attenuated by cyclosporine A.

Significance Cyclosporine A was one of the first drugs used in clinical practice to successfully rescue glucocorticoid-resistant inflammatory diseases. In this article we extend the characterization of glucocorticoid-resistant human Th17 cells, and demonstrate that this effector memory T-cell subset is reciprocally attenuated by cyclosporine A. This therapeutic paradigm was confirmed in a murine model of autoimmunity, refining our understanding of cyclosporine A’s effect on the adaptive immune response. These data support the rationale for Th17-targeting therapies in the treatment of glucocorticoid-resistant inflammation. Glucocorticoids remain the cornerstone of treatment for inflammatory conditions, but their utility is limited by a plethora of side effects. One of the key goals of immunotherapy across medical disciplines is to minimize patients’ glucocorticoid use. Increasing evidence suggests that variations in the adaptive immune response play a critical role in defining the dose of glucocorticoids required to control an individual’s disease, and Th17 cells are strong candidate drivers for nonresponsiveness [also called steroid resistance (SR)]. Here we use gene-expression profiling to further characterize the SR phenotype in T cells and show that Th17 cells generated from both SR and steroid-sensitive individuals exhibit restricted genome-wide responses to glucocorticoids in vitro, and that this is independent of glucocorticoid receptor translocation or isoform expression. In addition, we demonstrate, both in transgenic murine T cells in vitro and in an in vivo murine model of autoimmunity, that Th17 cells are reciprocally sensitive to suppression with the calcineurin inhibitor, cyclosporine A. This result was replicated in human Th17 cells in vitro, which were found to have a conversely large genome-wide shift in response to cyclosporine A. These observations suggest that the clinical efficacy of cyclosporine A in the treatment of SR diseases may be because of its selective attenuation of Th17 cells, and also that novel therapeutics, which target either Th17 cells themselves or the effector memory T-helper cell population from which they are derived, would be strong candidates for drug development in the context of SR inflammation.

CD14++CD16+ monocytes are enriched by glucocorticoid treatment and are functionally attenuated in driving effector T cell responses

Human peripheral monocytes have been categorized into three subsets based on differential expression levels of CD14 and CD16. However, the factors that influence the distribution of monocyte subsets and the roles that each subset plays in autoimmunity are not well studied. In this study, we show that circulating monocytes from patients with autoimmune uveitis exhibit a skewed phenotype toward intermediate CD14++CD16+ cells, and that this is associated with glucocorticoid therapy. We further demonstrate that CD14++CD16+ monocytes from patients and healthy control donors share a similar cell-surface marker and gene expression profile. Comparison of the effects of intermediate CD14++CD16+ monocytes with classical CD14++CD16− and nonclassical CD14+CD16++ monocytes revealed that the intermediate CD14++CD16+ subset had an attenuated capacity to promote both naive CD4+ T cell proliferation and polarization into a Th1 phenotype, and memory CD4+ T cell proliferation and IL-17 expression. Furthermore, CD14++CD16+ cells inhibit CD4+ T cell proliferation induced by other monocyte subsets and enhance CD4+ T regulatory cell IL-10 expression. These data demonstrate the impact of glucocorticoids on monocyte phenotype in the context of autoimmune disease and the differential effects of monocyte subsets on effector T cell responses.

Can endoscopy be avoided in the assessment of ulcerative colitis in clinical trials

Background: There is no gold standard index in the measurement of ulcerative colitis (UC) disease activity in clinical trials. Mucosal healing has been described as an important clinical endpoint requiring endoscopic assessment, which is unpleasant for the patient and may hamper recruitment to trials. The aim of this study was to determine whether endoscopy is necessary in the assessment of UC disease activity and whether a noninvasive disease activity index (partial Mayo score) could be used to predict the Mayo score. Methods: In all, 149 subjects with moderate to severe UC enrolled in a clinical trial were assessed using total and partial Mayo scores. Histologic assessment of biopsies was performed. A regression model was constructed to predict total Mayo score from the partial Mayo score and histology score from the Mayo score. A Bland–Altman test of agreement was performed. Results: The partial Mayo score correlated closely with the total Mayo score at week 4 (rho = 0.97) and week 8 (rho = 0.98). The model to predict total from partial Mayo score showed excellent correlation (rho = 0.97) and good agreement with the total Mayo score at week 4 and the week 8 validation set (rho = 0.97) and accurately classified disease severity (kappa = 0.82). The model to predict histology score from the Mayo score correlated only moderately with the actual histology score at week 4 (rho = 0.59) and week 8 (rho = 0.36). Conclusions: The Mayo score can be accurately predicted from the partial Mayo score. A noninvasive index can replace the Mayo score in future clinical trials. (Inflamm Bowel Dis 2012;)

Is liver biopsy necessary in the management of alcoholic hepatitis

Acute alcoholic hepatitis (AAH) is characterised by deep jaundice in patients with a history of heavy alcohol use, which can progress to liver failure. A clinical diagnosis of AAH can be challenging to make in patients without a clear alcohol history or in the presence of risk factors for other causes of acute liver failure. Other causes of acute on chronic liver failure such as sepsis or variceal haemorrhage should be considered. Liver biopsy remains the only reliable method to make an accurate diagnosis. However, there is controversy surrounding the use of liver biopsy in patients with AAH because of the risks of performing a percutaneous biopsy and limitations in access to transjugular biopsy. We review the existing literature and find there are few studies directly comparing clinical and histological diagnosis of AAH. In the small number of studies that have been conducted the correlation between a clinical and histological diagnosis of AAH is poor. Due to this lack of agreement together with difficulties in accessing transjugular liver biopsy outside tertiary referral centres and research institutions, we cannot advocate universal biopsy for AAH but there remains a definite role for liver biopsy where there is clinical diagnostic doubt or dual pathology. It also adds value in a clinical trial context to ensure a homogeneous trial population and to further our understanding of the disease pathology. Further prospective studies are required to determine whether non-invasive markers can be used to accurately diagnose AAH.

Molecular targets in the treatment of alcoholic hepatitis

Alcohol related costs to health and society are high. One of the most serious complications of alcohol misuse to the individual is the development of alcoholic hepatitis (AH), a clinical syndrome of jaundice and progressive inflammatory liver injury in patients with a history of recent heavy alcohol use. It has a poor outcome and few existing successful therapies. The use of glucocorticoids in patients with severe AH is still controversial and there remains a group of patients with glucocorticoid-resistant disease. However, as our understanding of the pathogenesis of the condition improves there are opportunities to develop new targeted therapies with specific actions to control liver inflammation without having a detrimental effect on the immune system as a whole. In this article we review the molecular mechanisms of AH concentrating on the activation of the innate and adaptive immune response. We consider existing treatments including glucocorticoids, anti-tumor necrosis factor therapy and pentoxifylline and their limitations. Using our knowledge of the disease pathogenesis we discuss possible novel therapeutic approaches. New targets include pro-inflammatory cytokines such as interleukin (IL)-17, chemokines and their receptors (for example IL-8, CXCL9 and CXCR3) and augmentation of anti-inflammatory molecules such as IL-10 and IL-22. And there is also future potential to consider combination therapy to selectively modulate the immune response and gain control of disease.

UK wide survey on the prevention of post-ERCP pancreatitis

Objective In 2010, the European Society of Gastrointestinal Endoscopy delivered guidelines on the prophylaxis of postendoscopic retrograde cholangiopancreatography (post-ERCP) pancreatitis (PEP). These included Grade A recommendations advising the use of prophylactic pancreatic stent (PPS) and non-steroidal anti-inflammatory drugs (NSAIDs) in high-risk cases. Our study aim was to capture the current practice of UK biliary endoscopists in the prevention of PEP. Design In summer 2012, an anonymous online 15-item survey was emailed to 373 UK consultant gastroenterologists, gastrointestinal surgeons and radiologists identified to perform ERCP. Results The response rate was 59.5% (222/373). Of the respondents, 52.5% considered ever using PPS for the prevention of PEP. PPS users always attempted insertion for the following procedural risk factors: pancreatic sphincterotomy (48.9%), suspected sphincter of Oddi dysfunction (46.5%), pancreatic duct instrumentation (35.9%), previous PEP (25.2%), precut sphincterotomy (8.5%) and pancreatic duct injection (7.8%). Prophylactic NSAID use was significantly associated with attempts at PPS placement (p<0.001). 64.1% of non-PPS users cited a lack of conviction in their benefit as the main reason for their decision. Self-reported pharmacological use rates for PEP prevention were: NSAIDs (34.6%), antibiotics (20.6%), rapid intravenous fluids (13.2%) and octreotide (1.6%). 6% routinely measured amylase post-ERCP. Conclusions Despite strong evidence-based guidelines for prevention of PEP, less than 53% of ERCP practitioners use pancreatic stenting or NSAIDs. This suggests a need for the development of British Society of Gastroenterology guidelines to increase awareness in the UK. Even among stent users, PPS are being underused for most high-risk cases. Prophylactic pharmacological measures were rarely used as was routine post-ERCP serum amylase measurement.

Immune dysfunction in acute alcoholic hepatitis

Acute alcoholic hepatitis (AAH) is a serious complication of alcohol misuse and has high short term mortality. It is a clinical syndrome characterised by jaundice and coagulopathy in a patient with a history of recent heavy alcohol use and is associated with profound immune dysfunction with a primed but ineffective immune response against pathogens. Here, we review the current knowledge of the pathogenesis and immune defects of AAH and identify areas requiring further study. Alcohol activates the immune system primarily through the disruption of gut tight junction integrity allowing the escape of pathogen-associated molecular particles (PAMPs) into the portal venous system. PAMPs stimulate cells expressing toll-like receptors (mainly myeloid derived cells) and initiate a network of intercellular signalling by secretion of many soluble mediators including cytokines and chemokines. The latter coordinates the infiltration of neutrophils, monocytes and T cells and results in hepatic stellate cell activation, cellular damage and hepatocyte death by necrosis or apoptosis. On the converse of this immune activation is the growing evidence of impaired microbial defence. Neutrophils have reduced phagocytic capacity and oxidative burst and there is recent evidence that T cell exhaustion plays a role in this.

NFκB and glucocorticoid receptor activity in steroid resistance

Resistance to the anti-inflammatory and immunosuppressive effects of steroids is an important clinical problem that complicates the treatment of approximately 30% of patients with conditions for which steroids are normally first-line therapy. Previous studies have shown that steroid-resistant (SR) patients have more severe disease and higher levels of inflammatory cytokine production than steroid-sensitive (SS) patients, but the molecular mechanisms for this remain poorly understood. Peripheral blood mononuclear cells from healthy volunteers were tested for steroid resistance by their in vitro response to the anti-proliferative effects of dexamethasone. The SR cohort had high baseline levels of NFκB DNA binding activity, equivalent to that in phytohemagglutinin (PHA)-stimulated SS cells. In SR cells, dexamethasone exposure, but not PHA, increased binding of the p65 NFκB subunit to the κB promoter element. Glucocorticoid receptor (GR) was not detected at either the κB promoter element or the glucocorticoid response element (GRE), suggesting that it does not translocate to the nucleus in these cells. Conversely, in SS cells, baseline p65 DNA binding activity was low and significantly increased by PHA, but not by dexamethasone. Unlike in SR cells, GR was detected at the κB element and at the GRE. These findings suggest that in SR patients, steroids may be harmful by increasing NFκB activity which would exacerbate disease by increasing transcription of inflammatory cytokines.

Long‐term outcome in patients with severe alcoholic hepatitis can be reliably determined using an in vitro measure of steroid sensitivity

Severe alcoholic hepatitis (SAH) has an overall mortality of 40% and is widely treated with steroids. However, a proportion of patients are steroid resistant and ultimately die from liver failure. Currently, the only existing model to predict response to steroids relies on laboratory parameters at baseline and after 7 days of steroid treatment and has 75% sensitivity in predicting death at 6 months. We have previously reported on a 48-hour in vitro measure of steroid sensitivity (known as the dexamethasone inhibition of lymphocyte proliferation assay [DILPA]) that predicts 6-month survival with 78% sensitivity. Here, we present results of a validation study performed in an independent cohort of 26 patients with SAH. Consecutive patients with SAH (defined as recent-onset jaundice with a bilirubin level >80 mmol/L and coagulopathy in patients heavily consuming alcohol with a Maddrey discriminant function [DF] >32) were recruited. All patients were treated with 4 weeks of prednisolone 40 mg daily (other therapies, including pentoxifylline and N-acetylcisteine, were not used). The DILPA was performed as previously described as soon as possible after admission and before prednisolone treatment. The maximum suppression of proliferation (Imax) was determined and a threshold of less than 60% was set to define steroid resistance, as previously described. Twenty-six patients were recruited between February 2010 and September 2012 (median age: 46; 23% female; median baseline DF: 49.7; 72% had ascites and 23% had overt hepatic encephalopathy) and followed up for at least 1 year (median time: 889 days). The accuracy of the DILPA in predicting 6-month survival, assessed by area under the receiver operating characteristic (AUROC), was 0.86. Combining this recent cohort with our previously published data set resulted in an AUROC of 0.84 for prediction of both 6and 12-month survival, which exceeds the AUROC for the Lille score of 0.73 and 0.71 at 6 months and 1 year, respectively. An Imax >60% had a 91% sensitivity in predicting 6-month survival (Fig. 1). Six-month and 1-year mortality in patients with Imax <60% was 74% versus 9% in those with Imax >60% (hazard ratio: 6.5). Overall 6-month mortality was 43% (14% at 28 days). The few subjects with outlying DILPA values did not have any specific clinical characteristics to explain their results and should be considered false positives and negatives. These results confirm that in vitro steroid sensitivity is a good measure of clinical steroid responsiveness and demonstrate the potential value of the DILPA as a rapid bioassay that can be performed at an early stage to accurately determine long-term outcome of patients with SAH, in particular to identify patients with a poor prognosis where alternative treatment strategies may be indicated.