Whole-genome sequencing of African Americans implicates differential genetic architecture in inflammatory bowel disease.

Whether or not populations diverge with respect to the genetic contribution to risk of specific complex diseases is relevant to understanding the evolution of susceptibility and origins of health disparities. Here, we describe a large-scale whole-genome sequencing study of inflammatory bowel disease encompassing 1,774 affected individuals and 1,644 healthy control Americans with African ancestry (African Americans). Although no new loci for inflammatory bowel disease are discovered at genome-wide significance levels, we identify numerous instances of differential effect sizes in combination with divergent allele frequencies. For example, the major effect at PTGER4 fine maps to a single credible interval of 22 SNPs corresponding to one of four independent associations at the locus in European ancestry individuals but with an elevated odds ratio for Crohn disease in African Americans. A rare variant aggregate analysis implicates Ca2+-binding neuro-immunomodulator CALB2 in ulcerative colitis. Highly significant overall overlap of common variant risk for inflammatory bowel disease susceptibility between individuals with African and European ancestries was observed, with 41 of 241 previously known lead variants replicated and overall correlations in effect sizes of 0.68 for combined inflammatory bowel disease. Nevertheless, subtle differences influence the performance of polygenic risk scores, and we show that ancestry-appropriate weights significantly improve polygenic prediction in the highest percentiles of risk. The median amount of variance explained per locus remains the same in African and European cohorts, providing evidence for compensation of effect sizes as allele frequencies diverge, as expected under a highly polygenic model of disease.

Improving Adherence to Clinical Practice Guidelines for Managing Gastric Intestinal Metaplasia Among Gastroenterologists at a US Academic Institution.

BACKGROUND: Clinical guidelines reserve endoscopic surveillance after a gastric intestinal metaplasia (GIM) diagnosis for high-risk patients. However, it is unclear how closely guidelines are followed in clinical practice. We examined the effectiveness of a standardized protocol for the management of GIM among gastroenterologists at a US hospital. METHODS: This was a preintervention and postintervention study, which included developing a protocol and education of gastroenterologists on GIM management. For the preintervention study, 50 patients with GIM were randomly selected from a histopathology database at the Houston VA Hospital between January 2016 and December 2019. For the postintervention study, we assessed change in GIM management in a cohort of 50 patients with GIM between April 2020 and January 2021 and surveyed 10 gastroenterologists. The durability of the intervention was assessed in a cohort of 50 GIM patients diagnosed between April 2021 and July 2021. RESULTS: In the preintervention cohort, GIM location was specified (antrum and corpus separated) in 11 patients (22%), and Helicobacter pylori testing was recommended in 11 of 26 patients (42%) without previous testing. Gastric mapping biopsies were recommended in 14% and surveillance endoscopy in 2%. In the postintervention cohort, gastric biopsy location was specified in 45 patients (90%, P <0.001) and H. pylori testing was recommended in 26 of 27 patients without prior testing (96%, P <0.001). Because gastric biopsy location was known in 90% of patients ( P <0.001), gastric mapping was not necessary, and surveillance endoscopy was recommended in 42% ( P <0.001). One year after the intervention, all metrics remained elevated compared with the preintervention cohort. CONCLUSIONS: GIM management guidelines are not consistently followed. A protocol for GIM management and education of gastroenterologists increased adherence to H. pylori testing and GIM surveillance recommendations.

Using Natural Language Processing to Automatically Identify Dysplasia in Pathology Reports for Patients With Barrett's Esophagus.

BACKGROUND & AIMS: Identifying dysplasia of Barrett's esophagus (BE) in the electronic medical record (EMR) requires manual abstraction of unstructured data. Natural language processing (NLP) creates structure to unstructured free text. We aimed to develop and validate an NLP algorithm to identify dysplasia in BE patients on histopathology reports with varying report formats in a large integrated EMR system. METHODS: We randomly selected 600 pathology reports for NLP development and 400 reports for validation from patients with suspected BE in the national Veterans Affairs databases. BE and dysplasia were verified by manual review of the pathology reports. We used NLP software (Clinical Language Annotation, Modeling, and Processing Toolkit; Melax Tech, Houston, TX) to develop an algorithm to identify dysplasia using findings. The algorithm performance characteristics were calculated as recall, precision, accuracy, and F-measure. RESULTS: In the development set of 600 patients, 457 patients had confirmed BE (60 with dysplasia). The NLP identified dysplasia with 98.0% accuracy, 91.7% recall, and 93.2% precision, with an F-measure of 92.4%. All 7 patients with confirmed high-grade dysplasia were classified by the algorithm as having dysplasia. Among the 400 patients in the validation cohort, 230 had confirmed BE (39 with dysplasia). Compared with manual review, the NLP algorithm identified dysplasia with 98.7% accuracy, 92.3% recall, and 100.0% precision, with an F-measure of 96.0%. CONCLUSIONS: NLP yielded a high degree of sensitivity and accuracy for identifying dysplasia from diverse types of pathology reports for patients with BE. The application of this algorithm would facilitate research and clinical care in an EMR system with text reports in large data repositories.

Comparative Effectiveness of Surveillance Colonoscopy Intervals on Colorectal Cancer Outcomes in a National Cohort of Patients with Inflammatory Bowel Disease.

BACKGROUND & AIMS: Surveillance colonoscopy is recommended to reduce colorectal cancer (CRC)-related morbidity and mortality in patients with inflammatory bowel disease (IBD). The comparative effectiveness of varying colonoscopy intervals on CRC outcomes among patients with IBD is unknown. METHODS: We performed a retrospective cohort study of patients with confirmed CRC within a cohort of 77,824 patients with IBD during 2000 to 2015 in the National Veterans Health Administration. We examined the association between colonoscopy surveillance intervals on CRC stage, treatment, or all-cause and cancer-specific mortality. The interval of colonoscopy prior to CRC diagnosis was categorized as those performed within <1 year, 1 to 3 years, 3 to 5 years, or none within 5 years. RESULTS: Among 566 patients with CRC-IBD, most (69.4%) did not have colonoscopy within 5 years prior to CRC diagnosis, whereas 9.7% had colonoscopy within 1 year prior to diagnosis, 17.7% within 1 to 3 years, and 3.1% between 3 and 5 years. Compared with no surveillance, colonoscopy within 1 year (adjusted odds ratio, 0.40; 95% confidence interval [CI], 0.20-0.82), and 1 to 3 years (adjusted odds ratio, 0.56; 95% CI, 0.32-0.98) were less likely to be diagnosed at late stage. Regardless of IBD type and duration, colonoscopy within 1 year was associated with a lower all-cause mortality (adjusted hazard ratio, 0.56; 95% CI, 0.36-0.88). CONCLUSIONS: In a national cohort of patients with CRC-IBD, colonoscopy within 3 years prior to CRC diagnosis was associated with early tumor stage at diagnosis, and colonoscopy within 1 year was associated with a reduced all-cause mortality compared with no colonoscopy. Our findings support colonoscopy intervals of 1 to 3 years in patients with IBD to reduce late-stage CRC and all-cause mortality.

Quality of Care Program Reduces Unplanned Health Care Utilization in Patients With Inflammatory Bowel Disease.

INTRODUCTION: There is significant variation in processes and outcomes of care for patients with inflammatory bowel disease (IBD), suggesting opportunities to improve quality of care. We aimed to determine whether a structured quality of care program can improve IBD outcomes, including the need for unplanned health care utilization. METHODS: We used a structured approach to improve adult IBD care in 27 community-based gastroenterology practices and academic medical centers. Patient-reported outcomes (PRO) and health care utilization were collected at clinical visits. Outcomes were monitored monthly using statistical process control charts; improvement was defined by special cause (nonrandom) variation over time. Multivariable logistic regression was applied to patient-level data. Nineteen process changes were offered to improve unplanned health care utilization. Ten outcomes were assessed, including disease activity, remission status, urgent care need, recent emergency department use, hospitalizations, computed tomography scans, health confidence, corticosteroid or opioid use, and clinic phone calls. RESULTS: We collected data prospectively from 20,382 discrete IBD visits. During the 15-month project period, improvement was noted across multiple measures, including need for urgent care, hospitalization, steroid use, and opioid utilization. Adjusted multivariable modeling showed significant improvements over time across multiple outcomes including urgent care need, health confidence, emergency department utilization, hospitalization, corticosteroid use, and opioid use. Attendance at monthly coached webinars was associated with improvement. DISCUSSION: Outcomes of IBD care were improved using a structured quality improvement program that facilitates small process changes, sharing of best practices, and ongoing feedback. Spread of these interventions may facilitate broad improvement in IBD care when applied to a large population.

Health Economic Impact of a Multicenter Quality-of-Care Initiative for Reducing Unplanned Healthcare Utilization Among Patients With Inflammatory Bowel Disease.

INTRODUCTION: A multicenter adult inflammatory bowel disease learning health system (IBD Qorus) implemented clinical care process changes for reducing unplanned emergency department visits and hospitalizations using a Breakthrough Series Collaborative approach. METHODS: Using Markov decision models, we determined the health economic impact of participating in the Collaborative from the third-party payer perspective. RESULTS: Across all 23 sites, participation in the Collaborative was associated with lower annual costs by an average of $2,528 ± $233 per patient when compared with the baseline period. DISCUSSION: Implementing clinical care process changes using a Collaborative approach was associated with overall cost savings. Future work should examine which specific interventions are most effective and whether such cost savings are sustainable.

Recommendations for Successful Transition of Adolescents With Inflammatory Bowel Diseases to Adult Care.

Adolescents and young adults diagnosed with inflammatory bowel diseases (IBDs) in pediatric care are vulnerable during their transition to adult care. There are 6 core elements of transition from pediatric to adult IBD care. We identified gaps in this transition and make recommendations for clinical practice and research. There have been few studies of transition policy (core element 1) or studies that tracked and monitored patients through the transition (core element 2). Several studies have assessed transition readiness (core element 3), but instruments for assessment were not validated using important outcomes such as disease control, health care use, adherence, quality of life, or continuity of care. There have been no studies of best practices for transition planning (core element 4), including how to best educate patients and facilitate gradual shifts in responsibility. A small number of longitudinal studies have investigated transfer of care (core element 5), but these were conducted outside of the United States; these studies found mixed results in short- and intermediate-term outcomes after transition completion (core element 6). We discuss what is known about the transition from pediatric to adult care for IBD, make recommendations to improve this process, and identify areas for additional research.

Association Between Inflammatory Bowel Disease and Colorectal Cancer Stage of Disease and Survival.

BACKGROUND: Inflammatory bowel disease (IBD) is associated with an increased risk of colorectal cancer (CRC). However, there are few data comparing outcomes between IBD and non-IBD-associated CRC. METHODS: Retrospective cohort study of patients with CRC identified from the Veteran Affairs (VA) Central Cancer Registry from 1998 to 2012 linked to national VA administrative claims to identify patients with IBD using a previously validated algorithm. The association between IBD status and stage of disease and overall risk of death were evaluated using multivariable logistic and Cox regression, respectively. RESULTS: Among 34,570 CRC patients, 217 had IBD. IBD patients were significantly younger for both colon and rectal cancer. IBD patients who developed rectal cancer were significantly more likely to present with locally advanced or metastatic disease (P = 0.007), but there was no difference in stage among patients with colon cancer. This difference persisted after multivariable adjustment (overall-odds ratio [OR] 1.40, 95% confidence interval [1.03-1.90]; colon-OR 1.22 [0.84-1.78]; rectum-OR 2.04 [1.22-3.40]). Total colectomy was more commonly performed among IBD patients. Overall, IBD was associated with a 52% increased risk of death (hazard ratio 1.52 [1.21-1.91]). CONCLUSIONS: Although IBD is associated with more advanced stage at diagnosis for rectal cancer, it is associated with a worse survival primarily in patients with colon cancer. Further work is needed to better understand the reason for these observed differences between IBD and non-IBD patients and to better delineate the impact of endoscopic surveillance on CRC care and outcomes in IBD patients.

Villin-1 and Gelsolin Regulate Changes in Actin Dynamics That Affect Cell Survival Signaling Pathways and Intestinal Inflammation.

BACKGROUND & AIMS: Cell stress signaling pathways result in phosphorylation of the eukaryotic translation initiation factor 2 subunit alpha (EIF2S1 or EIF2A), which affects regulation of protein translation. Translation reprogramming mitigates stress by activating pathways that result in autophagy and cell death, to eliminate damaged cells. Actin is modified during stress and EIF2A is dephosphorylated to restore homeostasis. It is not clear how actin affects EIF2A signaling. We studied the actin-binding proteins villin 1 (VIL1) and gelsolin (GSN) in intestinal epithelial cells (IECs) to determine whether they respond to cell stress response and affect signaling pathways. METHODS: We performed studies with mice with disruptions in Vil1 and Gsn (double-knockout mice). Wild-type (WT) mice either were or were not (controls) exposed to cell stressors such as tumor necrosis factor and adherent-invasive Escherichia coli. Distal ileum tissues were collected from mice; IECs and enteroids were cultured and analyzed by histology, immunoblots, phalloidin staining, immunohistochemistry, electron microscopy, and flow cytometry. HT-29 cells were incubated with cell stressors such as DTT, IFN, and adherent-invasive E coli or control agents; cells were analyzed by immunoblots and quantitative polymerase chain reaction. Green fluorescent protein and green fluorescent protein tagged mutant EIF2A were expressed from a lentiviral vector. The mouse immunity-related GTPase (IRGM1) was overexpressed in embryonic fibroblasts from dynamin1 like (DNM1L) protein-knockout mice or their WT littermates. IRGM1 was overexpressed in embryonic fibroblasts from receptor interacting serine/threonine kinase 1-knockout mice or their WT littermates. Human IRGM was overexpressed in human epithelial cell lines incubated with the DNM1L-specific inhibitor Mdivi-1. Mitochondria were analyzed by semi-quantitative confocal imaging. We performed immunohistochemical analyses of distal ileum tissues from 6-8 patients with Crohn's disease (CD) and 6-8 individuals without CD (controls). RESULTS: In IECs exposed to cell stressors, EIF2A signaling reduced expression of VIL1 and GSN. However, VIL1 and GSN were required for dephosphorylation of EIF2A and recovery from cell stress. In mouse and human IECs, prolonged, unresolved stress was accompanied by continued down-regulation of VIL1 and GSN, resulting in constitutive phosphorylation of EIF2A and overexpression of IRGM1 (or IRGM), which regulates autophagy. Overexpression of IRGM1 (or IRGM) induced cell death by necroptosis, accompanied by release of damage-associated molecular patterns (DAMPs). In double-knockout mice, constitutive phosphorylation of EIF2A and over-expression of IRGM1 resulted in spontaneous ileitis that resembled human CD in symptoms and histology. Distal ileum tissues from patients with CD had lower levels of VIL1 and GSN, increased phosphorylation of EIF2A, increased levels of IRGM and necroptosis, and increased release of nuclear DAMPs compared with controls. CONCLUSIONS: In studies of intestinal epithelial tissues from patients with CD and embryonic fibroblasts from mice, along with enteroids and human IEC lines, we found that induction of cell stress alters the cytoskeleton in IECs via changes in the actin-binding proteins VIL1 and GSN. Acute changes in actin dynamics increase IEC survival, whereas long-term changes in actin dynamics lead to IEC death and intestinal inflammation. IRGM regulates necroptosis and release of DAMPs to induce gastrointestinal inflammation, linking IRGM activity with CD.

Improving Anemia in Inflammatory Bowel Disease: Impact of the Anemia Care Pathway.

BACKGROUND: Anemia is a common complication of inflammatory bowel disease (IBD). Despite existing guidelines for anemia in IBD, it is frequently under-treated and the prevalence of anemia has remained high. To address this gap, the Crohn's and Colitis Foundation developed the Anemia Care Pathway (ACP). AIMS: To implement the ACP in a managed care setting and identify where it improves practice habits and where barriers remain. METHODS: The ACP was implemented from July 2016 through June 2017 and retrospectively studied. Run charts were used to identify shifts in iron deficiency screening and treatment as well as anemia prevalence. Results were compared to those of other providers in the same center not using the ACP. RESULTS: 640 IBD encounters were studied. In the ACP clinic (n = 213), anemics received iron therapy in only 30% of encounters at baseline but improved to 80%. Concurrently, anemia prevalence decreased from 48 to 25%. Screening for iron deficiency, however, did not improve. No shifts were seen in the non-ACP clinics (n = 427) across the same period despite awareness of the ACP and other guidelines. CONCLUSIONS: Across 1 year, we observed gaps in the screening and treatment of anemia in IBD. Although screening rates did not improve, the ACP appeared to reduce missed opportunities for iron therapy by about half. Most importantly, this was associated with an overall decrease in anemia prevalence. Future refinements to the ACP should be focused on enhanced screening and follow-up.

Caregiver Burden in Adults With Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic condition that has a relapsing and remitting disease course. There is high degree of inpatient and outpatient health care utilization by IBD patients along with a great deal of psychosocial stress associated with the condition. Patients frequently rely on family, friends, and other informal caregivers to provide medical, instrumental, and emotional support. The role of caregiving for adult IBD patients can lead to significant caregiver burden. At present, there are limited data on the existence of caregiver burden in adult IBD patients. Moreover, there are no specific measures for evaluating caregiver burden and there are no interventions targeting caregiver burden in adults with IBD. This review outlines the limited available data on caregiver burden in IBD, explores caregiver burden in other chronic conditions, and proposes applications of these data for creating screening and assessment tools and interventions for caregiver burden in IBD.

Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease.

BACKGROUND & AIMS: The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. METHODS: We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10-8 in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance. RESULTS: We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10-6): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B,PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles. CONCLUSIONS: We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry.

Hepatitis B Virus Screening and Reactivation in a National VA Cohort of Patients with Inflammatory Bowel Disease Treated with Tumor Necrosis Factor Antagonists.

BACKGROUND: Practice guidelines recommend screening for hepatitis B virus (HBV) infection prior to initiating treatment of inflammatory bowel disease (IBD) with anti-tumor necrosis factor (anti-TNF) therapy. However, the adherence to these screening guidelines and the clinical outcomes of HBV reactivation following anti-TNF use are not well known. METHODS: This is a retrospective cohort study using the Veterans Health Administration datasets for IBD patients with filled prescriptions for anti-TNFs from 2003 to 2011. Laboratory testing was used to define HBV screening status in the 12 months preceding anti-TNF initiation. Logistic regression models were used to identify predictors of HBV screening. Cases of potential HBV reactivation were identified using ICD-9 codes for HBV infection or acute liver failure or by medications used for HBV infection treatment, and manually reviewed for verification. RESULTS: We identified 3357 IBD patients with filled prescriptions for anti-TNF medications. The HBV testing prior to anti-TNF initiation was 8.1% in 2003 and increased to 43.2% by 2011, with an overall rate of 23.7%. In multivariate analysis, African-American race, facilities with a higher volume of IBD patients, and facilities with an academic affiliation were associated with a higher probability of HBV screening. We did not identify a single case of confirmed clinically relevant HBV reactivation after anti-TNF initiation during 7210 patient-years of medication use. CONCLUSIONS: HBV screening rates prior to anti-TNF initiation are low among IBD patients, but have increased over time. Despite low rates of screening, clinically significant HBV reactivation after anti-TNF initiation in this US cohort was nonexistent.

Determinants of Healthcare Utilization Among Veterans with Inflammatory Bowel Disease.

BACKGROUND: Identifying patient-level and disease-specific predictors of healthcare utilization in inflammatory bowel disease (IBD) may allow targeted interventions to reduce costs and improve outcomes. AIM: To identify demographic and clinical predictors of healthcare utilization among veterans with IBD. METHODS: We conducted a single-center cross-sectional study of veterans with IBD from 1998 to 2010. Demographics and disease characteristics were abstracted by manual chart review. Annual number of IBD-related visits was estimated by dividing total number of IBD-related inpatient and outpatient encounters by duration of IBD care. Associations between predictors of utilization were determined using stepwise multivariable linear regression. RESULTS: Overall, 676 patients (56% ulcerative colitis (UC), 42% Crohn's disease (CD), and 2% IBD unclassified (IBDU)) had mean 3.08 IBD-related encounters annually. CD patients had 3.59 encounters compared to 2.73 in UC (p < 0.01). In the multivariable model, Hispanics had less visits compared to Caucasians and African-Americans (2.09 vs. 3.09 vs. 3.42), current smokers had more visits than never smokers (3.54 vs. 2.43, p = 0.05), and first IBD visit at age <40 had more visits than age >65 (3.84 vs. 1.75, p = 0.04). UC pancolitis was associated with more visits than proctitis (3.47 vs. 2.15, p = 0.04). CD penetrating phenotype was associated with more encounters than inflammatory type (4.68 vs. 4.15, p = 0.04). CONCLUSIONS: We found that current tobacco use, age <40 at first IBD visit, UC pancolitis, and CD fistuilizing phenotype in addition to Caucasian and African-American race were independent predictors of increased healthcare utilization. Interventions should be targeted at these groups to decrease healthcare utilization and costs.

Accurate Identification of Fatty Liver Disease in Data Warehouse Utilizing Natural Language Processing.

INTRODUCTION: Natural language processing is a powerful technique of machine learning capable of maximizing data extraction from complex electronic medical records. METHODS: We utilized this technique to develop algorithms capable of "reading" full-text radiology reports to accurately identify the presence of fatty liver disease. Abdominal ultrasound, computerized tomography, and magnetic resonance imaging reports were retrieved from the Veterans Affairs Corporate Data Warehouse from a random national sample of 652 patients. Radiographic fatty liver disease was determined by manual review by two physicians and verified with an expert radiologist. A split validation method was utilized for algorithm development. RESULTS: For all three imaging modalities, the algorithms could identify fatty liver disease with >90% recall and precision, with F-measures >90%. DISCUSSION: These algorithms could be used to rapidly screen patient records to establish a large cohort to facilitate epidemiological and clinical studies and examine the clinic course and outcomes of patients with radiographic hepatic steatosis.

Characterization of genetic loci that affect susceptibility to inflammatory bowel diseases in African Americans.

BACKGROUND & AIMS: Inflammatory bowel disease (IBD) has familial aggregation in African Americans (AAs), but little is known about the molecular genetic susceptibility. Mapping studies using the Immunochip genotyping array expand the number of susceptibility loci for IBD in Caucasians to 163, but the contribution of the 163 loci and European admixture to IBD risk in AAs is unclear. We performed a genetic mapping study using the Immunochip to determine whether IBD susceptibility loci in Caucasians also affect risk in AAs and identify new associated loci. METHODS: We recruited AAs with IBD and without IBD (controls) from 34 IBD centers in the United States; additional controls were collected from 4 other Immunochip studies. Association and admixture loci were mapped for 1088 patients with Crohn's disease, 361 with ulcerative colitis, 62 with IBD type unknown, and 1797 controls; 130,241 autosomal single-nucleotide polymorphisms (SNPs) were analyzed. RESULTS: The strongest associations were observed between ulcerative colitis and HLA rs9271366 (P = 7.5 × 10(-6)), Crohn's disease and 5p13.1 rs4286721 (P = 3.5 × 10(-6)), and IBD and KAT2A rs730086 (P = 2.3 × 10(-6)). Additional suggestive associations (P < 4.2 × 10(-5)) were observed between Crohn's disease and IBD and African-specific SNPs in STAT5A and STAT3; between IBD and SNPs in IL23R, IL12B, and C2orf43; and between ulcerative colitis and SNPs near HDAC11 and near LINC00994. The latter 3 loci have not been previously associated with IBD, but require replication. Established Caucasian associations were replicated in AAs (P < 3.1 × 10(-4)) at NOD2, IL23R, 5p15.3, and IKZF3. Significant admixture (P < 3.9 × 10(-4)) was observed for 17q12-17q21.31 (IZKF3 through STAT3), 10q11.23-10q21.2, 15q22.2-15q23, and 16p12.2-16p12.1. Network analyses showed significant enrichment (false discovery rate <1 × 10(-5)) in genes that encode members of the JAK-STAT, cytokine, and chemokine signaling pathways, as well those involved in pathogenesis of measles. CONCLUSIONS: In a genetic analysis of 3308 AA IBD cases and controls, we found that many variants associated with IBD in Caucasians also showed association evidence with these diseases in AAs; we also found evidence for variants and loci not previously associated with IBD. The complex genetic factors that determine risk for or protection against IBD in different populations require further study.

Time Trends, Clinical Characteristics, and Risk Factors of Chronic Anal Fissure Among a National Cohort of Patients with Inflammatory Bowel Disease.

BACKGROUND: Chronic anal fissure (CAF) is a common problem that causes significant morbidity. Little is known about the risk factors of CAF among patients with inflammatory bowel disease (IBD). AIM: To study the clinical characteristics and prevalence of CAF among a cohort of IBD patients. METHODS: We performed a population-based study on IBD patients from the National Veterans Affairs administrative datasets from 1998 to 2011. IBD and AF were identified by ICD-9 diagnosis codes. RESULTS: We identified 60,376 patients with IBD between the ages of 18-90 years, 94% males, 59% diagnosed with ulcerative colitis (UC), and 88% were Caucasians. The overall prevalence of CAF was 4% for both males and females. African Americans (AA) were two times more likely to have CAF compared to Caucasians (8 vs. 4%; OR 2.0, 95% CI 1.6-20.2, p = 0.0001) or Hispanics (8 vs. 4.8%; OR 2.1, 95% CI 1.4-25.2, p = 0.0001). The prevalence of CAF significantly dropped with age from 7% at age group 20-50 to 1.5% at 60-90 (p = 0.0001). CD patients were two times more likely to have CAF than UC patients (6 vs. 3%; OR 1.9, 95% CI 1.5-18.2, p = 0.0001). The initial diagnosis of CAF occurred within 14 years after the initial diagnosis of IBD in 74.5% patients. CONCLUSIONS: CAF is more prevalent among IBD than what is reported in the general population and diagnosed after the diagnosis of IBD. CAF is more prevalent among patients with CD, younger patients, and AA. The current results lay the groundwork for further outcome studies relate to anal fissure such as utilization, hospitalization, and cost.