Tanvi Dhere

A Novel Microbiome Therapeutic Increases Gut Microbial Diversity and Prevents Recurrent Clostridium difficile Infection

BACKGROUND Patients with recurrent Clostridium difficile infection (CDI) have a ≥60% risk of relapse, as conventional therapies do not address the underlying gastrointestinal dysbiosis. This exploratory study evaluated the safety and efficacy of bacterial spores for preventing recurrent CDI. METHODS Stool specimens from healthy donors were treated with ethanol to eliminate pathogens. The resulting spores were fractionated and encapsulated for oral delivery as SER-109. Following their response to standard-of-care antibiotics, patients in cohort 1 were treated with SER-109 on 2 consecutive days (geometric mean dose, 1.7 × 10(9) spores), and those in cohort 2 were treated on 1 day (geometric mean dose, 1.1 × 10(8) spores). The primary efficacy end point was absence of C. difficile-positive diarrhea during an 8-week follow-up period. Microbiome alterations were assessed. RESULTS Thirty patients (median age, 66.5 years; 67% female) were enrolled, and 26 (86.7%) met the primary efficacy end point. Three patients with early, self-limiting C. difficile-positive diarrhea did not require antibiotics and tested negative for C. difficile at 8 weeks; thus, 96.7% (29 of 30) achieved clinical resolution. In parallel, gut microbiota rapidly diversified, with durable engraftment of spores and no outgrowth of non-spore-forming bacteria found after SER-109 treatment. Adverse events included mild diarrhea, abdominal pain, and nausea. CONCLUSIONS SER-109 successfully prevented CDI and had a favorable safety profile, supporting a novel microbiome-based intervention as a potential therapy for recurrent CDI.

Genome wide association (GWA) predictors of anti-TNFα therapeutic responsiveness in pediatric inflammatory bowel disease

Background: Interindividual variation in response to anti‐TNF&agr; therapy may be explained by genetic variability in disease pathogenesis or mechanism of action. Recent genome‐wide association studies (GWAS) in inflammatory bowel disease (IBD) have increased our understanding of the genetic susceptibility to IBD. The aim was to test associations of known IBD susceptibility loci and novel “pharmacogenetic” GWAS identified loci with primary nonresponse to anti‐TNF&agr; in pediatric IBD patients and develop a predictive model of primary nonresponse. Methods: Primary nonresponse was defined using the Harvey Bradshaw Index (HBI) for Crohns disease (CD) and partial Mayo score for ulcerative colitis (UC). Genotyping was performed using the Illumina Infinium platform. Chi‐square analysis tested associations of phenotype and genotype with primary nonresponse. Genetic associations were identified by testing known IBD susceptibility loci and by performing a GWAS for primary nonresponse. Stepwise multiple logistic regression was performed to build predictive models. Results: Nonresponse occurred in 22 of 94 subjects. Six known susceptibility loci were associated with primary nonresponse (P < 0.05). Only the 21q22.2/BRWDI loci remained significant in the predictive model. The most predictive model included 3 novel “pharmacogenetic” GWAS loci, the previously identified BRWD1, pANCA, and a UC diagnosis (R2 = 0.82 and area under the curve [AUC] = 0.98%). The relative risk of nonresponse increased 15‐fold when number of risk factors increased from 0–2 to ≥3. Conclusions: The combination of phenotype and genotype is most predictive of primary nonresponse to anti‐TNF&agr; in pediatric IBD. Defining predictors of response to anti‐TNF&agr; may allow the identification of patients who will not benefit from this class of therapy. Inflamm Bowel Dis 2010

Crohn’s Disease in an African-American Population

Objective:African-Americans have been underrepresented in most large Crohns disease (CD) trials. This study was undertaken to assess the course and character of CD in African-Americans in comparison with whites. Methods:We retrospectively compared the course and character of CD in African-American and white patients at 3 Atlanta hospitals. Ninety-nine patients (55 African-American, 44 whites) were enrolled. Telephone interviews and chart reviews were used to identify disease location, presence of fistulae and perirectal disease, surgical history, and medication use. Patients with ulcerative colitis or indeterminant colitis, and all non-African-Americans or whites, were excluded. Results:The numbers of male and female patients were similar (50 and 49). Overall, men comprised 54% of white patients and 47% of African-American patients. There were no significant differences in the setting in which CD were diagnosed, number of flares per year, or duration of symptoms before diagnosis. White patients were more likely to seek care for their CD in a clinic setting, both their primary care physicians (1.31 versus 0.21 visits/yr, P < 0.001) and their gastroenterologists (3.2 versus 2.3 visits/yr, P = 0.03). Small bowel (SB) disease was present more frequently in white patients, 84% versus 65% (P = 0.03), and SB resection was more common in this group, 59% versus 16% (P < 0.01). Colonic disease was more common in African-American patients, 89% versus 63% (P = 0.002). Perirectal fistulae were more frequent in African-American patients, 58% versus 22% (P < 0.001) white patients were more likely to report complete compliance with medical therapy, 77% versus 49% (P = 0.004). African-American patients more frequently discontinued medical therapy because they “felt better” (27% versus 9%, P = 0.02). Medication usage, including immunosuppressants, was similar in both groups, except that white patients were more likely to receive multiple doses of infliximab (34% versus 11%, P = 0.005). Both groups felt equally informed about CD, but white patients felt that their disease was under good control a greater percentage of the time, 71% versus 58% (P = 0.04). Conclusions:These data lend credence to the suggestion that the nature of CD may be different in African-Americans compared with whites. However, despite this apparent difference in disease manifestation, the contribution of socioeconomic factors, access to health care, and understanding of the disease likely play a role as well.

Fecal transplant is as effective and safe in immunocompromised as non-immunocompromised patients for Clostridium difficile

Dear Editor: Clostridium difficile infection (CDI) is a leading cause of nosocomial infection and is associated with significant morbidity andmortality. Immunocompromised (IC) patients are particularly at higher risk. Recurrence rates of up to 60 % have been reported after the third episode despite treatment with antibiotics. Recent published reports of fecalmicrobiota transplantation (FMT) in the IC population have shed light that the procedure proves to be effective and safe. No studies that compare the efficacy and adverse event rate of FMT between IC and non-IC patients currently exist. The aim of our study is to compare the response and serious adverse event (SAE) rates of FMT for recurrent or refractory CDI (RCDI) between IC patients and non-IC patients. We performed a single-center retrospective study on patients who received FMT for RCDI in a single tertiary care center. Donor stool was obtained from a universal donor, friend, or relative. We used a standardized protocol for preparation of stool used for FMT. Patients received FMT through the upper gastrointestinal route or by colonoscopy. Those who failed initial FMTwere eligible to receive additional FMT. Patients were considered IC as a result of one or more of the following: HIV infection (any CD4 count), AIDS-defining diagnosis or CD4<200/mm, inherited or primary immune disorders, active malignancy, and immunodeficient or immunosuppressed from a medical condition/medication including current or recent (<3 months) treatment with anti-neoplastic agent or immunosuppressant medications. Immunosuppressant medications included but were not limited tomonoclonal antibodies to B and T cells, anti-tumor necrosis factor agents, glucocorticoids, antimetabolites (azathioprine, 6-mercaptopurine, methotrexate), calcineurin inhibitors (tacrolimus and cyclosporine), and mycophenolate mofetil. Outcomes compared between the two populations included rates of overall and primary 12-week CDI response post-FMT and percentage of patients who experienced SAEs within 12 weeks of FMT. Overall response was defined as lack of relapse with diarrhea associated with a positive C difficile PCR within 12 weeks of the last FMT (patients were eligible to have up to three FMT prior to being considered as a FMT non-responder). Primary response was defined as lack of relapse with diarrhea associated with a positive C. difficile PCR testing within 12 weeks post single FMT. SAEs were defined as any death, life-threatening experience, hospitalization, or important medical event such as infection of inflammatory bowel disease flare within 12 weeks post-FMT. Patients were excluded from efficacy analysis if they did not have a minimum of 12 weeks post-FMT follow up. Data was collected from a total of 122 FMTs performed on 107 patients. Six patients were excluded due to loss of follow up during the post-FMT follow up period. Six were excluded from the efficacy analysis due to * Tanvi Dhere tdhere@emory.edu

Vitamin D status and bone mineral density in African American children with Crohn disease.

Background: Vitamin D deficiency and low bone mineral density (BMD) are complications of inflammatory bowel disease. Vitamin D deficiency is more prevalent among African Americans compared with whites. There are little data comparing differences in serum 25-hydroxyvitamin D (25OHD) concentrations and BMD between African American and white children with Crohn disease (CD). Methods: We compared serum 25OHD concentrations of African American children with CD (n = 52) to white children with CD (n = 64) and healthy African American controls (n = 40). We also analyzed BMD using dual-energy x-ray absorptiometry results from our pediatric CD population. Results: African American children with CD had lower serum 25OHD concentrations (16.1 [95% confidence interval, CI 14.5–17.9] ng/mL) than whites with CD (22.3 [95% CI 20.2–24.6] ng/mL; P < 0.001). African Americans with CD and controls exhibited similar serum 25OHD concentration (16.1 [95% CI 14.5–17.9] vs 16.3 [95% CI 14.4–18.4] ng/mL; NS). African Americans with CD exhibited no difference in serum 25OHD concentration when controlling for seasonality, disease severity, and surgical history, although serum 25OHD concentration was significantly decreased in overweight children (body mass index ≥85%, P = 0.003). Multiple regression analysis demonstrated that obese African American girls with CD had the lowest serum 25OHD concentrations (9.6 [95% CI 6.8–13.5] ng/mL). BMD was comparable between African American and white children with CD (z score −0.4 ± 0.9 vs −0.7 ± 1.2; NS). Conclusions: African American children with CD are more likely to have vitamin D deficiency compared with white children with CD, but have similar BMD. CD disease severity and history of surgery do not affect serum 25OHD concentrations among African American children with CD. African American children have low serum 25OHD concentrations, independent of CD, compared with white children. Future research should focus on how race affects vitamin D status and BMD in children with CD.

Successful treatment of chronic Pouchitis utilizing fecal microbiota transplantation (FMT): a case report.

Dear Editor: Ulcerative colitis (UC) is a chronic debilitating inflammatory condition medically treated with corticosteroids, aminosalicylates, immunomodulators, and biologics. Almost one third of UC patients ultimately require surgical interventions because of fulminant colitis, dysplasia, cancer, or medical refractory diseases. Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the current standard surgical intervention for severe chronic ulcerative colitis with failed medical treatment. Anastomotic leak, pouch failure, pelvic sepsis, and pouch ischemia can occur after the procedure. The most common long-term complication is pouchitis, an idiopathic inflammatory condition involving the ileal reservoir. Common presentations of pouchitis include increased stool frequency, urgency, incontinence, bloody stools, abdominal or pelvic discomfort, fatigue, malaise, and fever. The prevalence of pouchitis ranges from 23 to 46 %, with an annual incidence up to 40%. Though the majority of initial cases of pouchitis can be easily managed with a short course of antibiotics, in about 5 % of patients, inflammation of the pouch becomes chronic and a challenging problem tomanage. Fecal microbiota transplantation (FMT) is a novel therapy to transfer normal intestinal flora from a healthy donor to a patient with a medical condition potentially caused by disrupted homeostasis of intestinal microbiota or dysbiosis. FMT has been widely used in refractory Clostridium difficile infection (CDI) and recently it has gained popularity for treatment of inflammatory bowel disease (IBD). Previous studies suggested that manipulating the composition of intestinal flora through antibiotics, probiotics, and prebiotic achieved significant results for treating acute episodes of UC-associated pouchitis. However, currently there is no established effective treatment for chronic antibioticdependent or refractory pouchitis. In this report, we described a case of chronic antibiotic refractory pouchitis successfully treated with FMT through pouchoscopy. The effect has been sustainable at 6 months post-FMT.

Common NOD2 risk variants in African Americans with Crohn's disease are due exclusively to recent Caucasian admixture†

Background: Crohns disease (CD) is highly heritable. NOD2 has emerged as the main susceptibility gene among individuals of European ancestry; however, NOD2 does not appear to contribute to CD susceptibility among many non‐European populations. Todays African American (AA) population represents an admixture of West African (80%) and European (20%) ancestry. Since genotype‐based tools are becoming increasingly available for CD, it is important that we validate the risk variants in different populations, such as admixed AAs. Methods: We analyzed the NOD2 variants among admixed AAs (n = 321, 240 with CD and 111 healthy controls [HCs]) and nonadmixed West Africans (n = 40) by genotyping four known disease‐causing NOD variants. We extracted the publicly available 1000 Genomes data on NOD2 variants from 500 subjects of West African origin. Association with disease was evaluated by logistic regression. Results: An association with CD was found for the classical single nucleotide polymorphism (SNP) 1007fs (2.6% CD, 0% HC, P = 0.012); there was no association when the genotypic and allelic frequencies of the risk alleles were compared for SNPs R702W and G908R. No known NOD2 risk alleles were seen in either the West African cohort or in subjects of African ancestry from the 1000 Genomes project. Conclusions: The NOD2 gene is a risk for CD in AAs, although the allele frequencies and the attributable risk are much lower compared with Caucasians. The risk alleles are not seen in the West African population, suggesting that the risk for CD contributed by NOD2 among AAs is due exclusively to recent European admixture. (Inflamm Bowel Dis 2012;)

Ulcerative Colitis: Update on Medical Management

Ulcerative colitis (UC) is a chronic inflammatory bowel disease whose pathogenesis is multifactorial and includes influences from genes, the environment, and the gut microbiome. Recent advances in diagnosis and treatment have led to significant improvement in managing the disease. Disease monitoring with the use of therapeutic drug monitoring, stool markers, and assessment of mucosal healing have garnered much attention. The recent approval of vedolizumab for treatment of moderate to severe UC has been a welcome addition. Newer biologics, including those targeting the Janus tyrosine kinase (JAK) pathway, are on the horizon to add to the current armamentarium of anti-TNF alpha and anti-integrin therapies. The recent publication of the SCENIC consensus statement on surveillance and management of dysplasia in UC patients supports the use of chromoendoscopy over random biopsies in detecting dysplasia. This review highlights these recent advances along with others that have been made with ulcerative colitis.

Diverticulitis after fecal microbiota transplant for C. difficile infection.

and further molecular analysis. Follow-up at 4 years showed a normal psychomotor, social and intellectual development, scoliosis of the thoracic part of the backbone, and no facial or hand and feet dysmorphism. Using the comparative genomic hybridization technique we revealed deletions of 7q11.1–7q11.2, 16p11.2–16p13.2, 16p13.3, 16q11.2–16q12.2 and 19p13.1–19p13.3 chromosomal regions in the esophagus ( Figure 1 ) and no chromosomal aberrations in blood ( Figure 2 ) in the same patient resulting in somatic mosaicism. No other tissues were analyzed. We validated 19p13 deletion using quantitative real-time PCR and MLPA. Recent scientifi c reports suggest that in the process of cell diff erentiation genome rearrangements may occur ( 5–7 ). Th is somatic cell mosaicism can be formed aft er fertilization in the early stages of embryonic development, being one of the mechanisms for the diff erentiation of various tissues ( 8 ). More and more reports in the literature describe somatic mosaicism as well as the cause of various diseases ( 9 ). Th e chromosome deletions described by us in this paper are large DNA losses and may be pathogenic alterations with signifi cance in the etiology of this developmental defect. We suspect that 7q11.1–7q11.2, 16p11.2– 16p13.2, 16p13.3, 16q11.2–16q12.2 and 19p13.1–19p13.3 chromosomal regions may contain key genes, regulatory seque nces, or other genetic elements playing an important role in esophagus development. For example, the 19p13 chromosomal region contains the LDLR gene, which is involved in cholesterol metabolism. Cholesterol acts in the proper functioning of the Sonic Hedgehog signaling pathway, which is instrumental in patterning of the early embryo and is essential to foregut development ( 10 ). We hypothesize that genetic mosaicism may be the cause of the EA and this readily explains the diffi culty in identifying pathogenic mutations in patients with isolated EA.

Laboratory Testing of Donors and Stool Samples for Fecal Microbiota Transplantation for Recurrent Clostridium difficile Infection

ABSTRACT Fecal microbiota transplantation is an efficacious and inexpensive therapy for recurrent Clostridium difficile infection, yet its safety is thought to depend on appropriate fecal donor screening. FDA guidance for regulation of this procedure is in flux, but screening and manufacture of fecal material from asymptomatic donors present many challenges to clinical laboratories. This minireview summarizes FDA regulatory changes, principles of donor selection, and recommended laboratory screening practices for fecal microbiota transplantation.