Gil Y. Melmed

Genome-wide association identifies multiple ulcerative colitis susceptibility loci

Ulcerative colitis is a chronic, relapsing inflammatory condition of the gastrointestinal tract with a complex genetic and environmental etiology. In an effort to identify genetic variation underlying ulcerative colitis risk, we present two distinct genome-wide association studies of ulcerative colitis and their joint analysis with a previously published scan, comprising, in aggregate, 2,693 individuals with ulcerative colitis and 6,791 control subjects. Fifty-nine SNPs from 14 independent loci attained an association significance of P < 10−5. Seven of these loci exceeded genome-wide significance (P < 5 × 10−8). After testing an independent cohort of 2,009 cases of ulcerative colitis and 1,580 controls, we identified 13 loci that were significantly associated with ulcerative colitis (P < 5 × 10−8), including the immunoglobulin receptor gene FCGR2A, 5p15, 2p16 and ORMDL3 (orosomucoid1-like 3). We confirmed association with 14 previously identified ulcerative colitis susceptibility loci, and an analysis of acknowledged Crohns disease loci showed that roughly half of the known Crohns disease associations are shared with ulcerative colitis. These data implicate approximately 30 loci in ulcerative colitis, thereby providing insight into disease pathogenesis.

Human Intestinal Epithelial Cells Are Broadly Unresponsive to Toll-Like Receptor 2-Dependent Bacterial Ligands: Implications for Host-Microbial Interactions in the Gut

Intestinal epithelial cells (IEC) interact with a high density of Gram-positive bacteria and are active participants in mucosal immune responses. Recognition of Gram-positive organisms by Toll-like receptor (TLR)2 induces proinflammatory gene expression by diverse cells. We hypothesized that IEC are unresponsive to Gram-positive pathogen-associated molecular patterns and sought to characterize the functional responses of IEC to TLR2-specific ligands. Human colonic epithelial cells isolated by laser capture microscopy and IEC lines (Caco-2, T84, HT-29) were analyzed for expression of TLR2, TLR6, TLR1, and Toll inhibitory protein (Tollip) mRNA by RT-PCR and quantitative real-time PCR. Response to Gram-positive bacterial ligands was measured by NF-κB reporter gene activation and IL-8 secretion. TLR2 protein expression was analyzed by immunofluorescence and flow cytometry. Colonic epithelial cells and lamina propria cells from both uninflamed and inflamed tissue demonstrate low expression of TLR2 mRNA compared with THP-1 monocytes. IECs were unresponsive to TLR2 ligands including the staphylococcal-derived Ags phenol soluble modulin, peptidoglycan, and lipotechoic acid and the mycobacterial-derived Ag soluble tuberculosis factor. Transgenic expression of TLR2 and TLR6 restored responsiveness to phenol soluble modulin and peptidoglycan in IEC. In addition to low levels of TLR2 protein expression, IEC also express high levels of the inhibitory molecule Tollip. We conclude that IEC are broadly unresponsive to TLR2 ligands secondary to deficient expression of TLR2 and TLR6. The relative absence of TLR2 protein expression by IEC and high level of Tollip expression may be important in preventing chronic proinflammatory cytokine secretion in response to commensal Gram-positive bacteria in the gut.

Patients with Inflammatory Bowel Disease are at Risk for Vaccine-Preventable Illnesses

BACKGROUND:Patients with chronic, immune-mediated conditions such as inflammatory bowel disease (IBD) are often treated with long-term immunosuppressive therapies, potentially increasing their risk of developing an infection. Empiric data suggest that vaccines are underutilized in immunocompromised patients, despite published guidelines recommending their use. We aimed to assess exposure risk and immunization status among patients receiving care in an IBD specialty clinic.METHODS:Patients completed a self-administered, pretested, structured questionnaire during a routine visit for the management of IBD. Survey questions related to medical and immunization histories, and exposures to known risk factors for influenza, pneumococcus, viral hepatitis, and varicella. Additionally, in a subgroup of patients who agreed to donate a sample of blood, immune status to hepatitis A (HAV), hepatitis B (HBV), and varicella was determined.RESULTS:Two hundred four patients were asked to participate in the study; 169 completed surveys and comprised the study population. Mean age was 35 yr (range 13–75 yr). One hundred forty-six respondents (86%) reported current or prior use of immunosuppressive medications. Only 45% of respondents recalled tetanus immunization within the past 10 yr, 41 (28%) reported regularly receiving flu shots, and 13 (9%) reported having received pneumococcal vaccine. The most common reasons for nonimmunization with influenza included lack of awareness (49%) and concern for side effects (18%). Responses indicated that 75 (44%) patients were at risk for HBV but only 47 (28%) had been vaccinated against the infection; of patients with previous HBV vaccination, only three of nine (33%) had measurable antibodies against hepatitis B surface antigen.CONCLUSIONS:Immunization against selected vaccine-preventable illnesses was uncommon in patients with IBD, despite the presence of significant risk factors. Efforts to improve immunization status among patients with IBD and other chronic, immune-mediated conditions are needed.

LIFE AFTER RADICAL PROSTATECTOMY: A LONGITUDINAL STUDY

PURPOSE We investigate the longitudinal recovery of quality of life after radical prostatectomy in men with localized prostate cancer. MATERIALS AND METHODS We assessed the self-reported health related quality of life in 247 men undergoing radical prostatectomy for prostate cancer. Patients were assessed at baseline before surgery and postoperatively every 3 months for 1 year and then every 6 months for up to 48 months (median 30). We measured general and prostate specific health related quality of life with the RAND 36-Item Health Survey 1.0 SF-36 and University of California, Los Angeles Prostate Cancer Index. The Cox proportional hazards regression model was used to determine whether some patients were more likely than others to have a successful return to baseline functioning after treatment. RESULTS In the SF-36 60% of patients reached baseline in all domains by 3 months. By 12 months, greater than 90% of patients reached baseline in all domains. Mean recovery time for these domains was about 4(1/2) months. The recovery of urinary function to baseline was 21% at 3, 56% at 12 and 63% at 30 months, respectively. About 80% of patients recovered to baseline urinary bother. In the urinary domains patients who recovered did so at an average of 7 to 8 months, and there was little additional recovery after 18 months. By 1 year postoperatively, approximately a third of patients reached baseline sexual function and about half recovered to baseline sexual bother. At 2 years postoperatively, sexual function and bother returned to baseline in 40% and 60% of patients, respectively. Mean recovery time was about 11 months for sexual function and about 9 months for sexual bother. There was little additional recovery in the sexual domains after 18 to 24 months. In the bowel domains more than two thirds of patients returned to baseline by 3 months, and greater than 90% recovered by 12 months, with a mean recovery of 4.8 months. Unmarried men were more likely than those married to regain baseline sexual function (p = 0.03) and urinary function (p = 0.07). Patients who were 65 years and older were more likely than those younger to return to baseline sexual bother (p = 0.03). There were trends that showed patients with higher incomes as well as those who were white were more likely to recover baseline scores for urinary function and the physical component summary. Another trend suggested that men with a higher education were less likely to regain urinary function (p = 0.08). CONCLUSIONS Most quality of life recovery occurs early after radical prostatectomy, except in several domains, including urinary and sexual, which continue to improve even beyond 2 years postoperatively. Patients should be encouraged that recovery may continue for months or years after surgery.

Comparative Effectiveness of Immunosuppressants and Biologics for Inducing and Maintaining Remission in Crohn's Disease: A Network Meta-analysis

BACKGROUND & AIMS There is controversy regarding the best treatment for patients with Crohns disease because of the lack of direct comparative trials. We compared therapies for induction and maintenance of remission in patients with Crohns disease, based on direct and indirect evidence. METHODS We performed systematic reviews of MEDLINE, EMBASE, and Cochrane Central databases, through June 2014. We identified randomized controlled trials (N = 39) comparing methotrexate, azathioprine/6-mercaptopurine, infliximab, adalimumab, certolizumab, vedolizumab, or combined therapies with placebo or an active agent for induction and maintenance of remission in adult patients with Crohns disease. Pairwise treatment effects were estimated through a Bayesian random-effects network meta-analysis and reported as odds ratios (OR) with a 95% credible interval (CrI). RESULTS Infliximab, the combination of infliximab and azathioprine (infliximab + azathioprine), adalimumab, and vedolizumab were superior to placebo for induction of remission. In pair-wise comparisons of anti-tumor necrosis factor agents, infliximab + azathioprine (OR, 3.1; 95% CrI, 1.4-7.7) and adalimumab (OR, 2.1; 95% CrI, 1.0-4.6) were superior to certolizumab for induction of remission. All treatments were superior to placebo for maintaining remission, except for the combination of infliximab and methotrexate. Adalimumab, infliximab, and infliximab + azathioprine were superior to azathioprine/6-mercaptopurine: adalimumab (OR, 2.9; 95% CrI, 1.6-5.1), infliximab (OR, 1.6; 95% CrI, 1.0-2.5), infliximab + azathioprine (OR, 3.0; 95% CrI, 1.7-5.5) for maintenance of remission. Adalimumab and infliximab + azathioprine were superior to certolizumab: adalimumab (OR, 2.5; 95% CrI, 1.4-4.6) and infliximab + azathioprine (OR, 2.6; 95% CrI, 1.3-6.0). Adalimumab was superior to vedolizumab (OR, 2.4; 95% CrI, 1.2-4.6). CONCLUSIONS Based on a network meta-analysis, adalimumab and infliximab + azathioprine are the most effective therapies for induction and maintenance of remission of Crohns disease.

Guidelines for the appropriate use of non-steroidal anti-inflammatory drugs, cyclo-oxygenase-2-specific inhibitors and proton pump inhibitors in patients requiring chronic anti-inflammatory therapy

Aim : To rationalize decision making around the use of different non‐steroidal anti‐inflammatory drug (NSAID) treatment strategies in patients with varying degrees of gastrointestinal and cardiovascular risk.

Immunosuppression Impairs Response to Pneumococcal Polysaccharide Vaccination in Patients With Inflammatory Bowel Disease

OBJECTIVES:The treatment of inflammatory bowel disease (IBD) often includes immunosuppressive medications, which may increase the risk of vaccine-preventable illnesses. We aimed to assess the impact of immunosuppression on immune responses to pneumococcal vaccination in patients with IBD.METHODS:The study design consists of a prospective controlled clinical trial. This study was carried out at a tertiary-care IBD clinic. The subjects for the study belonged to one of the following three groups: adult patients with IBD on combination TNF-blockers and immunomodulators (Group A), those without immunosuppressive therapy (Group B), and age-matched healthy controls (Group C). The treatment consisted of immunization with 23-valent pneumococcal polysaccharide vaccines (PSVs). The main outcome was immune response for five serotypes defined as a twofold or greater increase from pre-vaccination titers and ⩾1 μg post-vaccination titer.RESULTS:Sixty-four subjects participated in the study: 20 in Group A, 25 in Group B, and 19 in Group C. Pre-vaccination titers were similar among the three groups. Vaccine responses were lower in Group A than in Group B (P⩽0.01 for four out of five antigens) and Group C (P<0.01 for all five antigens). Overall vaccine response was seen in 45, 80, and 85% of Groups A, B, and C (P=0.01), respectively.CONCLUSIONS:Immune response to PSV-23 is impaired in Crohns disease (CD) patients on combination immunosuppressive therapy but is normal among non-immunosuppressed patients. Given the unpredictable likelihood for immunosuppressive therapy, newly diagnosed patients with IBD should undergo vaccination before the initiation of immunosuppressive therapy.

Genetic Predictors of Medically Refractory Ulcerative Colitis

Background: Acute severe ulcerative colitis (UC) remains a significant clinical challenge and the ability to predict, at an early stage, those individuals at risk of colectomy for medically refractory UC (MR‐UC) would be a major clinical advance. The aim of this study was to use a genome‐wide association study (GWAS) in a well‐characterized cohort of UC patients to identify genetic variation that contributes to MR‐UC. Methods: A GWAS comparing 324 MR‐UC patients with 537 non‐MR‐UC patients was analyzed using logistic regression and Cox proportional hazards methods. In addition, the MR‐UC patients were compared with 2601 healthy controls. Results: MR‐UC was associated with more extensive disease (P = 2.7 × 10−6) and a positive family history of UC (P = 0.004). A risk score based on the combination of 46 single nucleotide polymorphisms (SNPs) associated with MR‐UC explained 48% of the variance for colectomy risk in our cohort. Risk scores divided into quarters showed the risk of colectomy to be 0%, 17%, 74%, and 100% in the four groups. Comparison of the MR‐UC subjects with healthy controls confirmed the contribution of the major histocompatibility complex to severe UC (peak association: rs17207986, P = 1.4 × 10−16) and provided genome‐wide suggestive association at the TNFSF15 (TL1A) locus (peak association: rs11554257, P = 1.4 × 10−6). Conclusions: A SNP‐based risk scoring system, identified here by GWAS analyses, may provide a useful adjunct to clinical parameters for predicting the natural history of UC. Furthermore, discovery of genetic processes underlying disease severity may help to identify pathways for novel therapeutic intervention in severe UC. (Inflamm Bowel Dis 2010)

Family History and Serology Predict Crohn’s Disease after Ileal Pouch-Anal Anastomosis for Ulcerative Colitis

PurposeApproximately 5 to 10 percent of patients undergoing ileal pouch-anal anastomosis with a diagnosis of ulcerative colitis are subsequently diagnosed with Crohn’s disease. Preoperative predictors for Crohn’s disease post-ileal pouch-anal anastomosis have not been prospectively defined.MethodsA total of 238 consecutive patients with ulcerative colitis or indeterminate colitis undergoing ileal pouch-anal anastomosis were prospectively enrolled into a longitudinal database. Clinical factors were assessed perioperatively. Serum drawn preoperatively was assayed for anti-Saccharomyces cerevisiae, antiouter membrane porin-C, anti-CBir1, and perinuclear antineutrophil cytoplasmic antibody using enzyme-linked immunosorbent assay. Crohn’s disease was defined by small bowel inflammation proximal to the ileal pouch or a perianal fistula identified at least three months after ileostomy closure. Predictors were assessed in a multivariate Cox proportional hazards model to predict the rate of Crohn’s disease after ileostomy closure.ResultsSixteen patients (7 percent) were diagnosed with Crohn’s disease; median time to Crohn’s disease was 19 (range, 1–41) months. Significant factors for postoperative Crohn’s disease after ileal pouch-anal anastomosis included family history of Crohn’s disease (hazard ratio, 8.4; 95 percent confidence interval, 2.96–24.1; P < 0.0001) and anti-Saccharomyces cerevisiae immunoglobulin-A seropositivity (hazard ratio, 3.14; 95 percent confidence interval, 1.1–9.81; P = 0.04). Crohn’s disease developed in only 8 of 198 patients (4 percent) without these predictors vs. 8 of 40 patients (20 percent) in those with at least one of these factors (P = 0.002). The cumulative risk of Crohn’s disease among patients with two risk factors (67 percent) was higher than in patients with either risk factor (18 percent) or neither risk factor (4 percent, P < 0.001).ConclusionsPatients with ulcerative colitis and indeterminate colitis with a family history of Crohn’s disease or preoperative anti-Saccharomyces cerevisiae immunoglobulin-A seropositivity are more likely to be diagnosed with Crohn’s disease after ileal pouch-anal anastomosis.

Biomarkers and Health-Related Quality of Life in End-Stage Renal Disease: A Systematic Review

BACKGROUND AND OBJECTIVES Health-related quality of life (HRQOL) predicts mortality in ESRD, yet adoption of HRQOL monitoring is not widespread, and regulatory authorities remain predominantly concerned with monitoring traditional biologic parameters. To assist with future efforts to adopt HRQOL monitoring while acknowledging the importance of biomarkers, this study sought to establish which domains of HRQOL are most affected by ESRD and to measure the strength of evidence linking common biomarkers to HRQOL in ESRD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS A systematic review was performed to identify studies that measured HRQOL in ESRD. Data were abstracted according to a conceptual model regarding the measurement of HRQOL differences, and HRQOL data were converted to weighted mean effect sizes and correlation coefficients. RESULTS The impact of ESRD was largest in the Short Form 36 domains of physical functioning (e.g., role-physical, vitality) and smallest in mental functioning (e.g., mental health, role-emotional). Dialysis adequacy, as measured by Kt/V, was a poor correlate for Short Form 36 scores. Similarly, mineral metabolism (e.g., calcium x phosphorous, parathyroid hormone) and inflammatory (e.g., C-reactive protein, TNF) biomarkers had small effect sizes and correlations with HRQOL. In contrast, hematocrit demonstrated small to moderate relationships with mental and physical HRQOL, and nutritional biomarkers (e.g., albumin, creatinine, body mass index) demonstrated moderate to large relationships. CONCLUSIONS HRQOL in ESRD is most affected in the physical domains, and nutritional biomarkers are most closely associated with these domains. In contrast, Kt/V, mineral metabolism indices, and inflammatory markers are poor HRQOL correlates.