Gastrointestinal bleeding and pro-angiogenic shift in the angiopoietin axis with continuous flow left ventricular assist device implantation.

BACKGROUND: Gastrointestinal bleeding (GIB) affects up to 40% of continuous-flow left ventricular assist device (CF-LVAD) recipients. A higher risk of GIB is seen in CF-LVAD recipients with lower device pulsatility without a known mechanism. One hypothesis is that the novel hemodynamics in CF-LVAD recipients affect angiogenesis signaling. We aimed to (1) measure serum levels of angiopoietin (Ang)-1, Ang-2, and VEGF-A in CF-LVAD recipients with and without GIB and in healthy controls and (2) evaluate correlations of those levels with hemodynamics. METHODS: We recruited 12 patients with CF-LVADs (six who developed GIB after device implantation) along with 12 age-matched controls without heart failure or GIB and measured Ang-1, Ang-2, and VEGF-A levels in serum samples from each patient. RESULTS: CF-LVAD recipients had significantly higher Ang-2 and lower Ang-1 levels compared to controls with no difference in VEGF-A levels. CF-LVAD recipients with GIB had lower Ang-1 levels than those without GIB. There were trends for pulse pressure to be positively correlated with Ang-1 levels and negatively correlated with Ang-2 levels in CF-LVAD recipients with no correlation observed in healthy controls. CONCLUSION: CF-LVAD recipients demonstrated a shift toward a pro-angiogenic phenotype in the angiopoietin axis that is significantly associated with GIB and may be linked to low pulse pressure.

The relationship between nutrition, gut dysbiosis, and pediatric sickle cell pain outcomes: A pilot study.

BACKGROUND: Nutritional deficiencies are prevalent in sickle cell disease (SCD) and may be associated with worse pain outcomes. Gut dysbiosis has been reported in patients with SCD and may contribute to both nutritional deficiencies and pain. OBJECTIVES: We tested the association of nutrition, fat-soluble vitamin (FSV) deficiency, and gut microbiome composition on clinical outcomes in SCD. Second, we measured the association between diet and exocrine pancreatic function on FSV levels. METHODS: Using case control design, we enrolled children with SCD (n = 24) and matched healthy controls (HC; n = 17, age, sex, race/ethnicity). Descriptive statistics summarized demographic and clinical data. Wilcoxson-rank tests compared FSV levels between cohorts. Regression modeling tested the association between FSV levels and SCD status. Welch's t-test with Satterthwaite adjustment evaluated associations between microbiota profiles, SCD status, and pain outcomes. RESULTS: Vitamin A and D levels were significantly decreased in participants with HbSS as compared to HC (vitamin A, p = < .0001, vitamin D, p = .014) independent of nutritional status. FSV correlated with dietary intake in SCD and HC cohorts. Gut microbial diversity was reduced in hemoglobin SS (HbSS) compared to hemoglobin SC (HbSC) and HC, p = .037 and .059, respectively. The phyla Erysipelotrichaceae and Betaproteobacteria were higher in SCD children reporting the highest quality-of-life (QoL) scores (p = .008 and .049, respectively), while Clostridia were higher in those with lower QoL scores (p = .03). CONCLUSION: FSV deficiencies and gut dysbiosis are prevalent in children with SCA. Gut microbial composition is significantly different in children with SCD with low QoL scores.

Crohn's Disease Patients Uniquely Contain Inflammatory Responses to Flagellin in a CD4 Effector Memory Subset.

BACKGROUND: Specific microbial antigens stimulate production of antibodies indicative of the aberrant immune response in Crohn's disease (CD). We tested for T cell reactivity linkage to B cell responses and now report on the prevalence, functionality, and phenotypic differences of flagellin-specific T cells among CD patients, ulcerative colitis (UC) patients, and control subjects and association with clinical features and flagellin seropositivity within CD patients. METHODS: Sera from non-inflammatory bowel disease control subjects, CD patients, and UC patients were probed for antibody reactivity to gut bacterial recombinant flagellin antigens. Peripheral blood mononuclear cells were measured for flagellin antigen (CBir1, A4 Fla2, FlaX) or control (Candida albicans, and CytoStim) reactivity analyzed by flow cytometry for CD154 and cytokine expression on CD4+ T cells. Supernatants from post-flagellin-stimulated and unstimulated cells were used to measure effects on epithelial barrier function. RESULTS: CD patients had a significantly higher percentage of flagellin-specific CD154+ CD4+ cells that have an effector memory T helper 1 and T helper 17 phenotype compared with UC patients and healthy control subjects. There was a positive correlation between the frequency of flagellin-specific CD154+ CD4+ effector memory T cells and serum levels of anti-flagellin immunoglobulin G in the CD patients. In addition, A4 Fla2-reactive T cells from active CD patients produced cytokines that can decrease barrier function in a gut epithelium. CONCLUSIONS: These findings demonstrate a Crohn's-associated flagellin-reactive CD4 cell subset distinct from UC patients and control subjects. There is a link between these cells and flagellin seropositivity. This CD4 cell subset could reflect a particular endophenotype of CD, leading to novel insight into its pathology and treatment.

Crohn's disease patients display inflammatory cytokine responses to flagellin antigens in an expanded effector memory CD4 subset that is not seen in ulcerative colitis or non­inflammatory bowel disease control subjects. These cells correlate with levels of the specific cognate anti-flagellin antibodies.

Celiac disease and the surgeon.

BACKGROUND: Celiac disease (CD), a disorder characterized by intestinal inflammation and villus atrophy, has protean manifestations. CD is being diagnosed more frequently but is often undiagnosed when encountered by surgeons. Our aim was to review aspects of CD that are relevant to the surgeon. METHODS: A PubMed database search was performed for articles published between January 2000 and December 2021 related to surgical issues in CD. RESULTS: CD is associated with a variety of conditions throughout the gastrointestinal tract. There is an increased risk of a variety of malignancies, including small intestinal tumors. Patients with CD are at an increased risk for operations for common problems such as appendicitis. Patients with undiagnosed CD undergoing operation may develop symptoms leading to diagnosis postoperatively. CONCLUSION: Surgeons should be aware of CD associated conditions, the risk of malignancy and confounding symptoms. Undiagnosed CD should be suspected if malabsorptive symptoms develop following operation.

Human Microbiota Flagellins Drive Adaptive Immune Responses in Crohn's Disease.

BACKGROUND AND AIMS: Crohn's disease and ulcerative colitis are characterized by dysregulated adaptive immune responses to the microbiota in genetically susceptible individuals, but the specificity of these responses remains largely undefined. Therefore, we developed a microbiota antigen microarray to characterize microbial antibody reactivity, particularly to human-derived microbiota flagellins, in inflammatory bowel disease. METHODS: Sera from healthy volunteers (n = 87) at the University of Alabama at Birmingham and from patients recruited from the Kirklin Clinic of University of Alabama at Birmingham Hospital, including patients with Crohn's disease (n = 152) and ulcerative colitis (n = 170), were individually probed against microbiota bacterial flagellins of both mouse and human origin and analyzed for IgG and IgA antibody responses. Circulating flagellin-reactive T effector (CD4+CD154+) and T regulatory (CD4+CD137+) cells were isolated and evaluated in selected patients. Resulting adaptive immune responses were compared with corresponding clinical data to determine relevancy to disease behavior. RESULTS: We show that patients with IBD express selective patterns of antibody reactivity to microbiota flagellins. Patients with Crohn's disease, but not patients with ulcerative colitis, display augmented serum IgG to human ileal-localized Lachnospiraceae flagellins, with a subset of patients having high responses to more than 10 flagellins. Elevated responses to CBir1, a mouse Lachnospiraceae flagellin used clinically to diagnose CD, correlated with multi-Lachnospiraceae flagellin reactivity. In this subset of patients with CD, multi-flagellin reactivity was associated with elevated flagellin-specific CD154+CD45RA- T memory cells, a reduced ratio of flagellin-reactive CD4+ T regulatory to T effector cells, and a high frequency of disease complications. CONCLUSIONS: Patients with Crohn's disease display strong adaptive immune response to human-derived Lachnospiraceae flagellins, which may be targeted for prognosis and future personalized therapies.

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.

Flagellin-Specific CD4 Cytokine Production in Crohn Disease and Controls Is Limited to a Small Subset of Antigen-Induced CD40L+ T Cells.

Flagellin is an immunodominant Ag in Crohn disease, with many patients showing anti-flagellin Abs. To study the clonality of flagellin-reactive CD4 cells in Crohn patients, we used a common CD154-based enrichment method following short-term Ag exposure to identify Ag-reactive CD4 cells. CD154 expression and cytokine production following Ag exposure compared with negative control responses (no Ag exposure) revealed that only a small fraction of CD154-enriched cells could be defined by Ag-reactive cytokine responses. This was especially true for low-frequency flagellin-reactive CD4 cells compared with polyclonal stimulation or Candida albicans Ag exposure. Moreover, we found that culture conditions used for the assay contributed to background CD40L (CD154) expression in the CD154-enriched CD4 cells. Using a cut-off rule based on flow cytometry results of the negative control CD154-enriched CD4 cells, we could reliably find the fraction of Ag-reactive cells in the CD154-enriched population. Ag-reactive CD4 cytokine production was restricted to CD4 cells with an effector memory phenotype and the highest levels of induced CD154 expression. This has important implications for identifying Ag-specific T cells of interest for single cell cloning, phenotyping, and transcriptomics.

Mucosa-Associated Microbiota in Barrett's Esophagus, Dysplasia, and Esophageal Adenocarcinoma Differ Similarly Compared With Healthy Controls.

INTRODUCTION: Alterations in the composition of the human gut microbiome and its metabolites have been linked to gut epithelial neoplasia. We hypothesized that differences in mucosa-adherent Barrett's microbiota could link to risk factors, providing risk of progression to neoplasia. METHODS: Paired biopsies from both diseased and nonaffected esophagus (as well as gastric cardia and gastric juice for comparison) from patients with intestinal metaplasia (n = 10), low grade dysplasia (n = 10), high grade dysplasia (n = 10), esophageal adenocarcinoma (n = 12), and controls (n = 10) were processed for mucosa-associated bacteria and analyzed by 16S ribosomal ribonucleic acid V4 gene DNA sequencing. Taxa composition was tested using a generalized linear model based on the negative binomial distribution and the log link functions of the R Bioconductor package edgeR. RESULTS: The microbe composition of paired samples (disease vs nondisease) comparing normal esophagus with intestinal metaplasia, low grade dysplasia, high grade dysplasia, and adenocarcinoma showed significant decreases in the phylum Planctomycetes and the archaean phylum Crenarchaeota (P < 0.05, false discovery rate corrected) in diseased tissue compared with healthy controls and intrasample controls (gastric juice and unaffected mucosa). Genera Siphonobacter, Balneola, Nitrosopumilus, and Planctomyces were significantly decreased (P < 0.05, false discovery rate corrected), representing <10% of the entire genus community. These changes were unaffected by age, tobacco use, or sex for Crenarcha. DISCUSSSION: There are similar significant changes in bacterial genera in Barrett's esophageal mucosa, dysplasia, and adenocarcinoma compared with controls and intrapatient unaffected esophagus. Further work will establish the biologic plausibility of these specific microbes' contributions to protection from or induction of esophageal epithelial dysplasia.

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.

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.

Helicobacter pylori infection inhibits phagocyte clearance of apoptotic gastric epithelial cells.

Increased apoptotic death of gastric epithelial cells is a hallmark of Helicobacter pylori infection, and altered epithelial cell turnover is an important contributor to gastric carcinogenesis. To address the fate of apoptotic gastric epithelial cells and their role in H. pylori mucosal disease, we investigated phagocyte clearance of apoptotic gastric epithelial cells in H. pylori infection. Human gastric mononuclear phagocytes were analyzed for their ability to take up apoptotic epithelial cells (AECs) in vivo using immunofluorescence analysis. We then used primary human gastric epithelial cells induced to undergo apoptosis by exposure to live H. pylori to study apoptotic cell uptake by autologous monocyte-derived macrophages. We show that HLA-DR(+) mononuclear phagocytes in human gastric mucosa contain cytokeratin-positive and TUNEL-positive AEC material, indicating that gastric phagocytes are involved in AEC clearance. We further show that H. pylori both increased apoptosis in primary gastric epithelial cells and decreased phagocytosis of the AECs by autologous monocyte-derived macrophages. Reduced macrophage clearance of apoptotic cells was mediated in part by H. pylori-induced macrophage TNF-α, which was expressed at higher levels in H. pylori-infected, compared with uninfected, gastric mucosa. Importantly, we show that H. pylori-infected gastric mucosa contained significantly higher numbers of AECs and higher levels of nonphagocytosed TUNEL-positive apoptotic material, consistent with a defect in apoptotic cell clearance. Thus, as shown in other autoimmune and chronic inflammatory diseases, insufficient phagocyte clearance may contribute to the chronic and self-perpetuating inflammation in human H. pylori infection.

Extracorporeal photopheresis (ECP) in patients with steroid-dependent Crohn's disease: an open-label, multicenter, prospective trial.

BACKGROUND: Extracorporeal photopheresis (ECP) involves ex vivo leukocyte treatment with methoxsalen and UVA light to generate a tolerogenic response. A previous trial demonstrated that ECP permits corticosteroid withdrawal in steroid-dependent Crohn's disease (CD) patients who were in clinical remission. We studied the effect of ECP on steroid withdrawal in steroid-dependent CD. METHODS: Patients with CD for ≥ 6 months, in remission at baseline while on steroids, but who had failed at ≥ 1 steroid withdrawal were included. Patients received two ECP treatments every 2 weeks for the 24-week steroid tapering period and underwent steroid-tapering. Patients completing steroid tapering could receive maintenance ECP (two treatments/week) every month for 24 weeks. RESULTS: Thirty-one patients (Crohn's Disease Activity Index [CDAI] score 91; Inflammatory Bowel Disease Questionnaire [IBDQ] 172.5) were enrolled (baseline corticosteroid dose, 20 mg/day); 65% were refractory to/intolerant of anti-tumor necrosis factor (TNF) agents or immunosuppressants. After 24 weeks of ECP, 7 of 31 (22.6%) patients discontinued steroids while maintaining a CDAI of <150. At week 24, the steroid dose for the remaining patients on corticosteroids was 10 mg (P < 0.003 vs. baseline) with a CDAI of 110 and an IBDQ of 179. Following maintenance treatment, three patients remained in steroid-free remission. The 10 patients in the study and receiving ECP at week 48 had a steroid dose of 3.5 mg with a CDAI of 40 and an IBDQ of 188. CONCLUSIONS: ECP permitted discontinuation or reduction of steroids in a population of refractory steroid-dependent CD patients. ECP may be useful in permitting steroid withdrawal in selected steroid-dependent CD patients. Ideally, these results need to be confirmed in a "sham-controlled clinical trial.

Inflammatory bowel diseases: emerging therapies and promising molecular targets.

An enormous amount of pathoetiologic information continues to accrue from animal models of inflammatory bowel disease and study of the gut microbiome that is providing expanded insight into the causes and mechanisms of inflammatory bowel diseases. This knowledge is being translated into new therapeutics that are being tested in Crohn's and ulcerative colitis patients with an aim to enhance treatment responses by moving away from immunosuppression and toward immunomodulation. In the last decade, the frontier of emerging IBD therapy has been dominated by biological agents that specifically target pro-inflammatory cytokines most notably tumor necrosis factor-alpha. However, it is clear that the gaps in therapy (primary and secondary non-response and the potential for drug side effects and intolerances) continue. To fill these gaps, various approaches are being employed to develop novel strategies, from inhibiting additional pro-inflammatory cytokines to focusing on blocking inflammatory cell trafficking, decreasing inflammatory cell mass, enhancing regulatory cell function and reinforcing epithelial barrier function. To these ends, aggressive and innovative research is being pursued to develop more robust treatment strategies and identify key molecular targets.

Remestemcel-L: human mesenchymal stem cells as an emerging therapy for Crohn's disease.

INTRODUCTION: Human mesenchymal stem cells (Prochymal brand of remestemcel-L) have been developed for experimental use in Crohn's disease and other conditions. Mesenchymal stems cells (MSCs) have been shown to inhibit inflammatory responses of innate and adaptive immune cells as well as have reparative effects on inflamed tissues. Promising preliminary therapeutic results of MSCs on gastrointestinal graft-versus-host disease have lead to Phase III trials for active Crohn's disease. AREAS COVERED: This review examines the discovery and characterization of mesenchymal stem cells, their immune effects, their use in animal models of disease, the production and administration of remestemcel-L and the published results of trials of remestemcel-L and alternative MSCs in Crohn's disease. EXPERT OPINION: The Prochymal brand of remestemcel-L represents the successful pharmaceutical development of mesenchymal stem cells for potential therapy in human disease. While preliminary results show promise of this therapy in terms of efficacy and safety, robust trials confirming efficacy results, explanation of the mechanism of response and estimates of effect compared to other biologics and immunosuppressants will be needed before this is an approved and widely accepted therapy.

Lack of compartmentalization of HIV-1 quasispecies between the gut and peripheral blood compartments.

Compartmental differences in human immunodeficiency virus type 1 (HIV-1) between the gut and peripheral blood and within the gut were examined. Biopsy specimens from the colon and ileum and peripheral blood samples were collected from chronically HIV-1-infected individuals. HIV-1 envelope sequences were examined from cell-associated DNA and RNA and virion RNA. Phylogenetic analysis revealed no evidence of compartmentalization of HIV-1 between the gut and peripheral blood and within the gut (colon and ileum). HIV-1 sequences detected in the gut were transcriptionally active and were also found in peripheral blood from matching time points, providing evidence of ongoing virus production in the gut and equilibrium of HIV-1 between the gut and peripheral blood compartments.

Multiple endoscopic biopsies in research subjects: safety results from a National Institutes of Health series.

BACKGROUND: Routine endoscopic mucosal biopsies are generally considered safe. However, the outcomes of performing large numbers of biopsies in subjects enrolled in research protocols have not been reported. OBJECTIVE: Our purpose was to assess the safety of taking numerous mucosal biopsy specimens during endoscopic procedures (eg, >20/endoscopic procedure) in research subjects. DESIGN: Single-center retrospective chart review. SETTING: Research hospital: National Institutes of Health (NIH) Clinical Center. PATIENTS: Volunteers who underwent research protocol endoscopies with large numbers of biopsies during 2001 to 2008 at the NIH. MAIN OUTCOME MEASUREMENTS: Charts were reviewed for the occurrence of procedure-related major/minor complications. RESULTS: A total of 253 research endoscopies were performed on 133 patients: 169 colonoscopies, 64 sigmoidoscopies, and 20 upper endoscopies. A total of 9,661 biopsy specimens were obtained for research and histopathologic examination (mean 38.2 +/- 15.6 per procedure). No major complications were identified. Minor complications occurred with 13 (5.1%) lower endoscopic procedures and included self-limited bleeding (4), pain (5), or both (4). There was no statistically significant association between the number of biopsies, type of procedure, location of research biopsies, operator, polypectomy, or the use of nonsteroidal anti-inflammatory drugs and the risk of complications. LIMITATIONS: Retrospective design, modest sample size. CONCLUSIONS: This is the first report on the safety of performing large numbers of endoscopic biopsies in research subjects. This practice is well tolerated and appears to have no more than minimal risk without appreciably increasing the risk of otherwise routine endoscopy.

Extracorporeal photopheresis for the treatment of refractory Crohn's disease: results of an open-label pilot study.

BACKGROUND: Extracorporeal photopheresis (ECP) is effective in immune-mediated disorders. A prospective, uncontrolled pilot study was conducted to evaluate the safety and efficacy of ECP in patients with active Crohn's disease (CD) who were refractory to or intolerant of immunosuppressants and/or anti-TNF therapies. METHODS: Patients with moderate-to-severely active CD (Crohn's Disease Activity Index [CDAI] 220-450 points) underwent 12 weeks of ECP treatment (Weeks 1-4: twice weekly, every week; Weeks 5-12: twice weekly, every other week). Clinical response was defined as a decrease in the CDAI of >or=100 points or remission (CDAI <150 points) at Week 12. Patients who responded at Week 12 could receive an additional 12 weeks of ECP treatment (twice weekly, every other week) in an extension study. RESULTS: Twenty-eight patients were enrolled with a mean baseline CDAI score of 314 (range 207-457). At Week 12, 14 patients (50%) responded; 13 patients responded within 6 weeks. Seven patients (25%) attained remission by Week 12. Three of 5 patients with open fistulae at baseline had fistula closure. Response was similar among patients naïve to anti-TNF agents and patients who had previously been refractory or intolerant to anti-TNF agents. Of the 12 patients who entered the extension study, 9 (75%) maintained their response at Week 24. CONCLUSIONS: In patients with moderate-to-severely active CD who were refractory to or intolerant of immunosuppressants and/or anti-TNF agents, ECP was well tolerated and induced clinical response (50%) and remission (25%) in patients. Most patients were able to maintain a response with continued treatments.

Persistence of HIV in gut-associated lymphoid tissue despite long-term antiretroviral therapy.

Human immunodeficiency virus (HIV) persists in peripheral blood mononuclear cells despite sustained, undetectable plasma viremia resulting from long-term antiretroviral therapy. However, the source of persistent HIV in such infected individuals remains unclear. Given recent data suggesting high levels of viral replication and profound depletion of CD4(+) T cells in gut-associated lymphoid tissue (GALT) of animals infected with simian immunodeficiency virus and HIV-infected humans, we sought to determine the level of CD4(+) T cell depletion as well as the degree and extent of HIV persistence in the GALT of infected individuals who had been receiving effective antiviral therapy for prolonged periods of time. We demonstrate incomplete recoveries of CD4(+) T cells in the GALT of aviremic, HIV-infected individuals who had received up to 9.9 years of effective antiretroviral therapy. In addition, we demonstrate higher frequencies of HIV infection in GALT, compared with PBMCs, in these aviremic individuals and provide evidence for cross-infection between these 2 cellular compartments. Together, these data provide a possible mechanism for the maintenance of viral reservoirs revolving around the GALT of HIV-infected individuals despite long-term viral suppression and suggest that the GALT may play a major role in the persistence of HIV in such individuals.

Excess IL-12 but not IL-23 accompanies the inflammatory bowel disease associated with common variable immunodeficiency.

BACKGROUND & AIMS: Common variable immunodeficiency (CVID) patients can develop an idiopathic inflammatory bowel disease resulting in chronic diarrhea and life-threatening malabsorption. This study was designed to assess the status of the gastrointestinal tract and to define the mucosal immune abnormalities in patients with and without symptomatic gut inflammatory disease. METHODS: CVID patients underwent tests of gut absorption, peripheral blood mononuclear cell phenotyping, and upper and lower endoscopy for histology and lamina propria mononuclear cell (LPMC) cytokine production. RESULTS: CVID patients with gastrointestinal symptoms differed from asymptomatic CVID patients by having significantly longer duration of disease and lower body mass index, D-xylose absorption, serum albumin, CD4/CD45RA cells, CD3/CD25 cells, and natural killer cells. Symptomatic CVID patients showed diffuse histologic inflammatory changes in the duodenal and colonic mucosa including villus blunting, increased lamina propria and intraepithelial lymphocytes, and epithelial apoptosis, less frequently seen in asymptomatic patients. LPMCs from symptomatic CVID patients produced significantly higher T-helper (Th) 1 cytokines, interleukin-12, and interferon-gamma. Compared with the Th1 cytokines produced by LPMCs from Crohn's disease, CVID patients did not produce excess amounts of interleukin-23, interleukin-17, or tumor necrosis factor-alpha. CONCLUSIONS: The idiopathic inflammatory bowel disease associated with gastrointestinal symptoms in CVID is a unique combination of diverse histologic findings accompanied by excessive Th1 cytokine production, distinct from that in Crohn's disease. These data show that human gut mucosal inflammatory disease can occur with excess interleukin-12 and interferon-gamma production alone and provide a rationale for developing targeted therapies for this complication of CVID.