Fecal Microbiota Transplantation engraftment after budesonide or placebo in patients with active ulcerative colitis using pre-selected donors: a randomized pilot study.

BACKGROUND: Fecal microbiota transplantation (FMT) shows some efficacy in treating patients with ulcerative colitis (UC), although variability has been observed among donors and treatment regimens. We investigated the effect of FMT using rationally selected donors after pretreatment with budesonide or placebo in active UC. METHODS: Patients ≥ 18 years old with mild to moderate active UC were randomly assigned to three weeks budesonide (9 mg) or placebo followed by four weekly infusions of a donor feces suspension. Two donors were selected based on microbiota composition, Treg induction and SCFA production in mice. The primary endpoint was engraftment of donor microbiota after FMT. In addition, clinical efficacy was assessed. RESULTS: In total, 24 patients were enrolled. Pretreatment with budesonide did not increase donor microbiota engraftment (p=0.56) nor clinical response, and engraftment was not associated with clinical response. At week 14, 10/24 (42%) of patients achieved (partial) remission. Remarkably, patients treated with FMT suspensions from one donor were associated with clinical response (80% of responders, p<0.05) but had lower overall engraftment of donor microbiota. Furthermore, differences in the taxonomic composition of the donors and the engraftment of certain taxa were associated with clinical response. CONCLUSION: In this small study, pretreatment with budesonide did not significantly influence engraftment or clinical response after FMT. However, clinical response appeared donor-dependent. Response to FMT may be related to transfer of specific strains instead of overall engraftment, demonstrating the need to characterize mechanisms of actions of strains that maximize therapeutic benefit in ulcerative colitis.

Interobserver agreement of current and new proposed endoscopic scores for postoperative recurrence in Crohn's disease.

BACKGROUND AND AIMS: The modified Rutgeerts' score (mRS) is widely used for the assessment of endoscopic postoperative recurrence (ePOR) in Crohn's disease (CD) after ileocolic resection to guide therapeutic decisions. To improve the validity and prognostic value of this endoscopic assessment, two new scores have been proposed. This study assessed the interobserver agreement of the current (mRS) and new endoscopic scores for ePOR in CD. METHODS: Sixteen Dutch academic and non-academic IBD specialists assessed endoscopic videos (n=71) of postoperative CD patients (n=66) retrieved from nine Dutch centers. Each video was assessed for the degree of inflammation by four gastroenterologists using the mRS and the new proposed endoscopic score: REMIND score (separate score of anastomosis and neoterminal ileum) and updated Rutgeerts score (assessment of lesions at the anastomotic line, ileal inlet, ileal body and neoterminal ileum). In addition, lesions at the ileal body, ileal inlet, neoterminal ileum, colonic and/or ileal blind loop were separately assessed. Interobserver agreement was assessed using Fleiss' weighted kappa. RESULTS: Fleiss' weighted kappa for the mRS was 0.67 (95% confidence interval [CI] 0.59-0.74). The weighted kappa for the REMIND score was 0.73 (95% CI 0.65-0.80) for lesions in the neoterminal ileum and 0.46 (95% CI 0.35-0.58) for anastomotic lesions. The weighted kappa for the updated Rutgeerts' score was 0.69 (95% CI 0.62-0.77). The weighted kappa for lesions in the ileal body, ileal inlet, neoterminal ileum, colonic and ileal blind loop was 0.61 (95% CI 0.49-0.73), 0.63 (95% CI 0.54-0.72), 0.61 (95% CI 0.49-0.74), 0.83 (95% CI 0.62-1.00) and 0.68 (95% CI 0.46-0.89). CONCLUSION: The interobserver agreement of the mRS is substantial. Similarly, the interobserver agreement is substantial for the updated Rutgeerts' score. According to the REMIND score, the interobserver agreement was substantial for lesions in the neoterminal ileum, whereas only moderate for anastomotic lesions. Since therapeutic decisions in clinical practice are based on these assessments and these scores are used as outcome measure in clinical studies, further improvement of the interobserver agreement is essential.

Deficits in geriatric assessment are important in relation to fatigue in older patients with Inflammatory Bowel Disease.

BACKGROUND: No previous study has investigated fatigue in older patients with Inflammatory Bowel Disease (IBD). AIMS: To describe the prevalence of fatigue in older patients and compare it to the prevalence in younger patients with IBD, and to determine factors associated with fatigue. METHODS: A prospective, multicenter cohort study, including older- (≥ 65 years) and younger patients with IBD (18-64 years). A geriatric assessment was performed in older patients to measure deficits in geriatric assessment (DiG). Fatigue was defined by one item from the short Inflammatory Bowel Disease Questionnaire. Active disease was defined as the presence of clinical or biochemical disease activity. RESULTS: Fatigue prevalence in the 405 older patients varied between 45.4% (71/155) in active disease to 23.6% (60/250) in remission. Fatigue prevalence in 155 younger patients was 59.5% (47/79) and 57.4% (89/155), respectively. Female sex, clinical disease activity, use of immunomodulators and presence of DiG were associated with fatigue in older patients with IBD. CONCLUSIONS: Fatigue prevalence is lower in older patients with IBD compared to younger patients with IBD, but increases when active disease is present. Clinicians should be aware that fatigue is a relevant symptom in older patients with IBD, as it is associated with DiG.

Preoperative screening and prehabilitation strategies prior to ileocolic resection in patients with Crohn's disease are not incorporated in routine care.

PURPOSE: Recently, recommendations on perioperative care have been published to optimize postoperative outcomes in preoperative patients with inflammatory bowel disease. This study evaluated the current use of preoperative screening and prehabilitation strategies (PS) prior to elective ileocolic resection (ICR) in patients with Crohn's disease (CD). METHODS: Patients with CD who underwent an elective ICR were identified from a Dutch prospective cohort study. Primary endpoint was to evaluate to what extent IBD-relevant PS were applied in patients with CD prior to ICR according to the current recommendations. RESULTS: In total, 109 CD patients were included. Screening of nutritional status was performed in 56% of the patients and revealed malnutrition in 46% of these patients. Of the malnourished patients, 46% was referred to a dietitian. Active smoking and alcohol consumption were reported in 20% and 28%; none of these patients were referred for a cessation program. A preoperative anemia was diagnosed in 61%, and ferritin levels were assessed in 26% of these patients. Iron therapy was started in 25% of the patients with an iron deficiency anemia. Exposure to corticosteroids at time of ICR was reported in 29% and weaned off in 3%. Consultation of a dietitian, psychologist, and physiotherapist was reported in 36%, 7%, and 3%. Physical fitness was assessed in none of the patients. CONCLUSION: PS are not routinely applied and not individually tailored in the preoperative setting prior to elective ICR in patients with CD. Prior to implementation, future research on the costs and effectiveness of PS on postoperative outcomes and quality of life is necessary.

Prophylactic Medication for the Prevention of Endoscopic Recurrence in Crohn's Disease: a Prospective Study Based on Clinical Risk Stratification.

BACKGROUND: To prevent recurrence after ileocolonic resection [ICR] in Crohn's disease [CD], postoperative prophylaxis based on risk stratification is recommended in international guidelines. This study aimed to evaluate postoperative CD recurrence after implementation of a clinical management algorithm and to determine the predictive value of clinical and histological risk factors [RFs]. METHODS: In this multicentre, prospective cohort study, CD patients [≥16 years] scheduled for ICR were included. The algorithm advised no postoperative medication for low-risk patients, and treatment with prophylaxis [immunosuppressant/biological] for high-risk patients [≥1 RF: active smoking, penetrating disease, prior ICR]. Clinical and histological RFs [active inflammation, granulomas, plexitis in resection margins] for endoscopic recurrence [Rutgeerts' score ≥i2b at 6 months] were assessed using logistic regression and ROC curves based on predicted probabilities. RESULTS: In total, 213 CD patients after ICR were included [age 34.5 years; 65% women] (93 [44%] low-risk; 120 [56%] high-risk: 45 [38%] smoking; 51 [43%] penetrating disease; 51 [43%] prior ICR). Adherence to the algorithm was 82% in low-risk [no prophylaxis] and 51% in high-risk patients [prophylaxis]. Endoscopic recurrence was higher in patients treated without prophylaxis than with prophylaxis in both low [45% vs 16%, p = 0.012] and high-risk patients [49% vs 26%, p = 0.019]. Clinical risk stratification including the prescription of prophylaxis corresponded to an area under the curve [AUC] of 0.70 (95% confidence interval [CI] 0.61-0.79). Clinical RFs combined with histological RFs increased the AUC to 0.73 [95% CI 0.64-0.81]. CONCLUSION: Adherence to this management algorithm is 65%. Prophylactic medication after ICR prevents endoscopic recurrence in low- and high-risk patients. Clinical risk stratification has an acceptable predictive value, but further refinement is needed.

Anemia and Iron Deficiency in Outpatients with Inflammatory Bowel Disease: Ubiquitous Yet Suboptimally Managed.

Background: Iron deficiency (ID) and anemia in patients with Inflammatory Bowel Disease (IBD) are associated with a reduced quality of life. We assessed the prevalence of ID and anemia in Dutch outpatients with IBD and compared routine ID(A) management among medical professionals to the European Crohn's and Colitis Organisation (ECCO) treatment guidelines. Methods: Between January and November 2021, consecutive adult outpatients with IBD were included in this study across 16 Dutch hospitals. Clinical and biochemical data were extracted from medical records. Additionally, medical professionals filled out questionnaires regarding routine ID(A) management. Results: In total, 2197 patients (1271 Crohn's Disease, 849 Ulcerative Colitis, and 77 IBD-unclassified) were included. Iron parameters were available in 59.3% of cases. The overall prevalence of anemia, ID, and IDA was: 18.0%, 43.4%, and 12.2%, respectively. The prevalence of all three conditions did not differ between IBD subtypes. ID(A) was observed more frequently in patients with biochemically active IBD than in quiescent IBD (ID: 70.8% versus 23.9%; p < 0.001). Contrary to the guidelines, most respondents prescribed standard doses of intravenous or oral iron regardless of biochemical parameters or inflammation. Lastly, 25% of respondents reported not treating non-anemic ID. Conclusions: One in five patients with IBD suffers from anemia that­despite inconsistently measured iron parameters­is primarily caused by ID. Most medical professionals treat IDA with oral iron or standard doses of intravenous iron regardless of biochemical inflammation; however, non-anemic ID is often overlooked. Raising awareness about the management of ID(A) is needed to optimize and personalize routine care.

Real-world experience of switching from intravenous to subcutaneous vedolizumab maintenance treatment for inflammatory bowel diseases.

BACKGROUND: Subcutaneous (SC) vedolizumab is effective in inflammatory bowel diseases (IBD) when administered after induction with two infusions. AIM: To assess the effectiveness, safety and pharmacokinetics of a switch from intravenous (IV) to SC maintenance vedolizumab in patients with IBD METHODS: In this prospective cohort study, patients with IBD who had ≥4 months IV vedolizumab were switched to SC vedolizumab. We studied the time to discontinuation of SC vedolizumab, adverse events (AEs), changes in clinical and biochemical outcomes and vedolizumab concentrations at baseline, and weeks 12 and 24. RESULTS: We included 82 patients with Crohn's disease (CD) and 53 with ulcerative colitis (UC). Eleven (13.4%) patients with CD and five (9.4%) with UC discontinued SC vedolizumab after a median of 18 (IQR 8-22) and 6 weeks (IQR 5-10), respectively. Four patients with CD switched to a different drug due to loss of response, nine switched back to IV vedolizumab due to adverse events, and three due to needle fear. Common AEs were injection site reactions (n = 15) and headache (n = 6). Median clinical and biochemical disease activity remained stable after the switch. Median serum vedolizumab concentrations increased from 19 µg/ml at the time of the switch to 31 µg/ml 12 weeks after the switch (p < 0.005). CONCLUSIONS: Switching from IV to SC vedolizumab maintenance treatment is effective in patients with CD or UC. However, 9% of patients were switched back to IV vedolizumab due to adverse events or fear of needles.

Comment on Szczubelek et al. Effectiveness of Crohn's Disease Exclusion Diet for Induction of Remission in Crohn's Disease Adult Patients. Nutrients 2021, 13, 4112.

We read with interest the manuscript by Szczubelek et al. [...].

Deficits in Geriatric Assessment Associate With Disease Activity and Burden in Older Patients With Inflammatory Bowel Disease.

BACKGROUND & AIMS: We aimed to perform geriatric assessment in older patients with inflammatory bowel disease (IBD) to evaluate which IBD characteristics associate with deficits in geriatric assessment and the impact of deficits on disease burden (health-related quality of life). METHODS: A prospective multicenter cohort study including 405 consecutive outpatient patients with IBD aged ≥65 years. Somatic domain (comorbidity, polypharmacy, malnutrition), impairments in (instrumental) activities of daily living, physical capacity (handgrip strength, gait speed), and mental (depressive symptoms, cognitive impairment) and social domain (life-partner) were assessed. Deficits in geriatric assessment were defined as ≥2 abnormal domains; 2-3 moderate deficits and 4-5 severe deficits. Clinical (Harvey Bradshaw Index >4/partial Mayo Score >2) and biochemical (C-reactive protein ≥10 mg/L and/or fecal calprotectin ≥250 µg/g) disease activity and disease burden (short Inflammatory Bowel Disease Questionnaire) were assessed. RESULTS: Somatic domain (51.6%) and activities of daily living (43.0%) were most frequently impaired. A total of 160 (39.5%) patients had moderate deficits in their geriatric assessment; 32 (7.9%) severe. Clinical and biochemical disease activity associated with deficits (clinical: adjusted odds ratio, 2.191; 95% confidence interval, 1.284-3.743; P = .004; biochemical: adjusted odds ratio, 3.358; 95% confidence interval, 1.936-5.825; P < .001). Deficits in geriatric assessment independently associate with lower health-related quality of life. CONCLUSION: Deficits in geriatric assessment are highly prevalent in older patients with IBD. Patients with active disease are more prone to deficits, and deficits associate with lower health-related quality of life, indicating higher disease burden. Prospective data validating impact of frailty and geriatric assessment on outcomes are warranted to further improve treatment strategies.

Ustekinuma b for Crohn's Disease: Two-Year Results of the Initiative on Crohn and Colitis (ICC) Registry, a Nationwide Prospective Observational Cohort Study.

AIMS: Ustekinumab is a monoclonal antibody that selectively targets p40, a shared subunit of the cytokines interleukin [IL]-12 and IL-23. It is registered for the treatment of inflammatory bowel diseases. We assessed the 2-year effectiveness and safety of ustekinumab in a real world, prospective cohort of patients with Crohn's disease [CD]. METHODS: Patients who started ustekinumab were prospectively enrolled in the nationwide Initiative on Crohn and Colitis [ICC] Registry. At weeks 0, 12, 24, 52 and 104, clinical remission Harvey Bradshaw Index≤ 4 points], biochemical remission (faecal calprotectin ≤ 200 µg/g and/or C-reactive protein ≤5 mg/L], perianal fistula remission, extra-intestinal manifestations, ustekinumab dosage and safety outcomes were determined. The primary outcome was corticosteroid-free clinical remission at week 104. RESULTS: In total, 252 CD patients with at least 2 years of follow-up were included. Of all included patients, the proportion of patients in corticosteroid-free clinical remission was 32.3% [81/251], 41.4% [104/251], 39% [97/249] and 34.0% [84/247] at weeks 12, 24, 52 and 104, respectively. In patients with combined clinical and biochemical disease activity at baseline [n = 122], the corticosteroid-free clinical remission rates were 23.8% [29/122], 35.2% [43/122], 40.0% [48/120] and 32.8% [39/119] at weeks 12, 24, 52 and 104, respectively. The probability of remaining on ustekinumab treatment after 52 and 104 weeks in all patients was 64.3% and 54.8%, respectively. The main reason for discontinuing treatment after 52 weeks was loss of response [66.7%]. No new safety issues were observed. CONCLUSION: After 104 weeks of ustekinumab treatment, one-third of CD patients were in corticosteroid-free clinical remission.

Comorbidity, not patient age, is associated with impaired safety outcomes in vedolizumab- and ustekinumab-treated patients with inflammatory bowel disease-a prospective multicentre cohort study.

BACKGROUND: Few data are available on the effects of age and comorbidity on treatment outcomes of vedolizumab and ustekinumab in inflammatory bowel disease (IBD). AIMS: To evaluate the association between age and comorbidity with safety and effectiveness outcomes of vedolizumab and ustekinumab in IBD. METHODS: IBD patients initiating vedolizumab or ustekinumab in regular care were enrolled prospectively. Comorbidity prevalence was assessed using the Charlson Comorbidity Index (CCI). Association between age and CCI, both continuously assessed, with safety outcomes (any infection, hospitalisation, adverse events) during treatment, and effectiveness outcomes (clinical response and remission, corticosteroid-free remission, clinical remission combined with biochemical remission) after 52 weeks of treatment were evaluated. Multivariable logistic regression was used to adjust for confounders. RESULTS: We included 203 vedolizumab- and 207 ustekinumab-treated IBD patients, mean age 42.2 (SD 16.0) and 41.6 (SD 14.4). Median treatment duration 54.0 (IQR 19.9-104.0) and 48.4 (IQR 24.4-55.1) weeks, median follow-up time 104.0 (IQR 103.1-104.0) and 52.0 weeks (IQR 49.3-100.4). On vedolizumab, CCI associated independently with any infection (OR 1.387, 95% CI 1.022-1.883, P = 0.036) and hospitalisation (OR 1.586, 95% CI 1.127-2.231, P = 0.008). On ustekinumab, CCI associated independently with hospitalisation (OR 1.621, 95% CI 1.034-2.541, P = 0.035). CCI was not associated with effectiveness, and age was not associated with any outcomes. CONCLUSIONS: Comorbidity - but not age - is associated with an increased risk of hospitalisations on either treatment, and with any infection on vedolizumab. This underlines the importance of comorbidity assessment and safety monitoring of IBD patients.

Ustekinumab for Crohn's Disease: Results of the ICC Registry, a Nationwide Prospective Observational Cohort Study.

BACKGROUND AND AIMS: Ustekinumab is approved for the treatment of Crohn's disease [CD]. Systematically registered prospective real-world data are scarce. We therefore aimed to study the effectiveness, safety and usage of ustekinumab for CD in everyday practice. METHODS: We prospectively enrolled CD patients initiating ustekinumab in regular care between December 2016 and January 2019. Clinical (Harvey Bradshaw Index [HBI]), biochemical (C-reactive protein [CRP] and faecal calprotectin [FCP]), extra-intestinal manifestations and, peri-anal fistula activity, ustekinumab dosage, concomitant medication use, and adverse events were documented at weeks 0, 12, 24, and 52. The primary outcome was corticosteroid-free clinical remission. RESULTS: In total, 221 CD patients were included (98.6% anti-tumour necrosis factor [TNF] and 46.6% vedolizumab exposed) with a median follow-up of 52.0 weeks [interquartile range 49.3-58.4]. Corticosteroid-free clinical remission rates at weeks 24 and 52 were 38.2% and 37.1%, respectively. An initial dosing schedule of 8 weeks, compared to 12 weeks, correlated with a lower discontinuation rate [20.0% vs 42.6%, p = 0.01], but comparable corticosteroid-free clinical remission at week 52 (46.3% [q8w] vs 34.6% [q12w], p = 0.20). There was no clinical benefit of combination therapy after 52 weeks when compared to ustekinumab monotherapy [combi 40.6% vs mono 36.0%, p = 0.64]. At baseline, 28 patients had active peri-anal fistula, of whom 35.7% showed complete clinical resolution after 24 weeks. During follow-up we encountered six severe infections [3.5 per 100 patient-years], with all patients being on concomitant immunosuppressant therapies. Ustekinumab treatment discontinuation was observed in 75 [33.9%] patients mainly due to lack of response. CONCLUSION: Ustekinumab is a relatively safe and effective treatment option for CD patients with prior failure of anti-TNF and anti-integrin therapies.

Towards a Food Pharmacy: Immunologic Modulation through Diet.

Patients frequently wonder whether their dietary pattern influences the course of inflammatory bowel disease (IBD). Many patients even avoid certain foods that aggravate their symptoms. Although interest in nutritional interventions is rising among physicians, the current application of nutritional interventions in the IBD population is limited due to the lack of scientific evidence from clinical trials. Several studies, however, have identified associations between diet, gut microbiota, intestinal epithelial integrity, and mucosal immune responses. In patients consuming predominantly a Western diet high in n-6 poly-unsaturated fatty acids (PUFAs), sugars, and meat, and low in fruits and vegetables, an impaired gut epithelial barrier and disturbances in the intestinal microbiota have been observed, resulting in a chronic mucosal inflammation. An anti-inflammatory diet may restore this disbalance. In this review, we discuss the effects of diet on the composition of the microbiota, the gut epithelial barrier function, and the mucosal immune system.

European Crohn's and Colitis Organisation Topical Review on Complementary Medicine and Psychotherapy in Inflammatory Bowel Disease.

Patients with inflammatory bowel disease [IBD] increasingly use alternative and complementary therapies, for which appropriate evidence is often lacking. It is estimated that up to half of all patients with IBD use various forms of complementary and alternative medicine during some point in their disease course. Considering the frequent use of such therapies, it is crucial that physicians and patients are informed about their efficacy and safety in order to provide guidance and evidence-based advice. Additionally, increasing evidence suggests that some psychotherapies and mind-body interventions may be beneficial in the management of IBD, but their best use remains a matter of research. Herein, we provide a comprehensive review of some of the most commonly used complementary, alternative and psychotherapy interventions in IBD.

Mir-142-3p target sequences reduce transgene-directed immunogenicity following intramuscular adeno-associated virus 1 vector-mediated gene delivery.

BACKGROUND: Muscle represents an important tissue target for adeno-associated virus (AAV) vector-mediated gene transfer in muscular, metabolic or blood-related genetic disorders. However, several studies have demonstrated the appearance of immune responses against the transgene product after intramuscular AAV vector delivery that resulted in a limited efficacy of the treatment. Use of microRNAs that are specifically expressed in antigen-presenting cells (APCs) is a promising approach for avoiding those immune responses. Cellular mir-142-3p, which is APC-specific, is able to repress the translation of its target cellular transcripts by binding to a specific target sequences. METHODS: In the present study, we explored the potential of mir-142-3p specific target sequences with respect to reducing or abolishing immune responses directed against ovalbumin (OVA), a highly immunogenic protein, expressed as transgene and delivered by AAV1 vector administered intramuscularly. RESULTS: The occurrence of immune responses against OVA transgene following intramuscular delivery by AAV have been described previously and resulted in the loss of OVA protein expression. In the present study, we demonstrate that OVA protein expression was maintained when mir-142-3pT sequences were incorporated into the expression cassette. The sustained expression of OVA protein over time correlated with a reduced increase in anti-OVA antibody levels. Furthermore, no cellular infiltrates were observed in the muscle tissue when AAV1 vectors containing four or eight repeats of mir-142-3p target sequences after the OVA sequence were used. CONCLUSIONS: The rising humoral and cellular immune responses against OVA protein after intramuscular delivery can be efficiently reduced by the use of mir-142-3p target sequences.

Murine CD4⁺CD25⁻ cells activated in vitro with PMA/ionomycin and anti-CD3 acquire regulatory function and ameliorate experimental colitis in vivo.

BACKGROUND: Induced regulatory T (iTreg) lymphocytes show promise for application in the treatment of allergic, autoimmune and inflammatory disorders. iTreg cells demonstrate advantages over natural Treg (nTreg) cells in terms of increased number of starting population and greater potential to proliferate. Different activation methods to generate iTreg cells result in iTreg cells that are heterogeneous in phenotype and mechanisms of suppression. Therefore it is of interest to explore new techniques to generate iTreg cells and to determine their physiological relevance. METHODS: Using phorbol myristate acetate (PMA)/ionomycin and anti-CD3 activation of CD4⁺CD25⁻ cells we generated in vitro functional CD4⁺CD25⁻ iTreg (TregPMA) cells. Functionality of the generated TregPMA cells was tested in vivo in a mouse model of inflammatory bowel disease (IBD) - CD45RB transfer colitis model. RESULTS: TregPMA cells expressed regulatory markers and proved to ameliorate the disease phenotype in murine CD45RB transfer colitis model. The body weight loss and disease activity scores for TregPMA treated mice were reduced when compared to diseased control group. Histological assessment of colon sections confirmed amelioration of the disease phenotype. Additionally, cytokine analysis showed decreased levels of proinflammatory colonic and plasma IL-6, colonic IL-1 ß and higher levels of colonic IL-17 when compared to diseased control group. CONCLUSIONS: This study identifies a new method to generate in vitro iTreg cells (TregPMA cells) which physiological efficacy has been demonstrated in vivo.

Teaching tolerance: New approaches to enzyme replacement therapy for Pompe disease.

Babies born with Pompe disease require life-long treatment with enzyme-replacement therapy (ERT). Despite the human origin of the therapy, recombinant human lysosomal acid α glucosidase (GAA, rhGAA), ERT unfortunately leads to the development of high titers of anti-rhGAA antibody, decreased effectiveness of ERT, and a fatal outcome for a significant number of children who have Pompe disease. The severity of disease, anti-drug antibody (ADA) development, and the consequences thereof are directly related to the degree of the enzyme deficiency. Babies born with a complete deficiency GAA are said to have cross-reactive immunologic material (CRIM)-negative Pompe disease and are highly likely to develop GAA ADA. Less frequently, GAA ADA develop in CRIM-positive individuals. Currently, GAA-ADA sero-positive babies are treated with a combination of immunosuppressive drugs to induce immunological tolerance to ERT, but the long-term effect of these regimens is unknown. Alternative approaches that might redirect the immune response toward antigen-specific tolerance without immunosuppressive agents are needed. Methods leading to the induction of antigen-specific regulatory T cells (Tregs), using peptides such as Tregitopes (T regulatory cell epitopes) are under consideration for the future treatment of CRIM-negative Pompe disease. Tregitopes are natural T cell epitopes derived from immunoglobulin G (IgG) that cause the expansion and activation of regulatory T cells (Treg). Teaching the immune system to tolerate GAA by co-delivering GAA with Tregitope peptides might dramatically improve the lives of CRIM-negative babies and could be applied to other enzyme replacement therapies to which ADA have been induced.

Adeno-associated virus mediated delivery of Tregitope 167 ameliorates experimental colitis.

AIM: To explore the anti-inflammatory potential of adeno-associated virus-mediated delivery of Tregitope 167 in an experimental colitis model. METHODS: The trinitrobenzene sulfonate (TNBS) model of induced colitis was used in Balb/c mice. Subsequently after intravenous adeno-associated virus-mediated regulatory T-cell epitopes (Tregitope) delivery, acute colitis was initiated by intra-rectal administration of 1.5 mg TNBS in 40% ethanol followed by a second treatment with TNBS (0.75 mg in 20% ethanol) 8 d later. Control groups included mice not treated with TNBS (healthy control group) and mice treated by TNBS only (diseased group). At the time of sacrifice colon weight, the disease activity index and histology damage score were determined. Immunohistochemical staining of the colonic tissues was performed to asses the cellular infiltrate and the presence of transcription factor forkhead Box-P3 (Foxp3). Thymus, mesenteric lymph nodes, liver and spleen tissue were collected and the corresponding lymphocyte populations were further assessed by flow cytometry analysis for the expression of CD4+ T cell and regulatory T cell associated markers. RESULTS: The Tregitope 167 treated mice gained an average of 4% over their initial body weight at the time of sacrifice. In contrast, the mice treated with TNBS alone (no Tregitope) developed colitis, and lost 4% of their initial body weight at the time of sacrifice (P < 0.01). The body weight increase that had been observed in the mice pre-treated with Tregitope 167 was substantiated by a lower disease activity index and a decreased colon weight as compared to the diseased control group (P < 0.01 and P < 0.001, respectively). Immunohistochemical staining of the colonic tissues for CD4+ showed that inflammatory cell infiltrates were present in TNBS treated mice with or without administration with tregitope 167 and that these cellular infiltrates consisted mainly of CD4+ cells. For both TNBS treated groups CD4+ T cell infiltrates were observed in the sub-epithelial layer and the lamina propria. CD4+ T cell infiltrates were also present in the muscularis mucosa layer of the diseased control mice, but were absent in the Tregitope 167 treated group. Numerous Foxp3 positive cells were detected in the lamina propria and sub-epithelium of the colon sections from mice treated with Tregitope 167. Furthermore, the Foxp3 and glycoprotein A repetitions predominant markers were significantly increased in the CD4+ T lymphocyte population in the thymus of the mice pre-treated with adeno-associated virus serotype 5 (cytomegalovirus promoter-Tregitope 167), as cytomegalovirus promoter compared to lymphocyte populations in the thymus of diseased and the healthy control mice (P < 0.05 and P < 0.001, respectively). CONCLUSION: This study identifies adeno-associated virus-mediated delivery of regulatory T-cell epitope 167 as a novel anti-inflammatory approach with the capacity to decrease intestinal inflammation and induce long-term remission in inflammatory bowel disease.

Gene and cell therapy based treatment strategies for inflammatory bowel diseases.

Inflammatory bowel diseases (IBD) are a group of chronic inflammatory disorders most commonly affecting young adults. Currently available therapies can result in induction and maintenance of remission, but are not curative and have sometimes important side effects. Advances in basic research in IBD have provided new therapeutic opportunities to target the inflammatory process involved. Gene and cell therapy approaches are suitable to prevent inflammation in the gastrointestinal tract and show therefore potential in the treatment of IBD. In this review, we present the current progress in the field of both gene and cell therapy and future prospects in the context of IBD. Regarding gene therapy, we focus on viral vectors and their applications in preclinical models. The focus for cell therapy is on regulatory T lymphocytes and mesenchymal stromal cells, their potential for the treatment of IBD and the progress made in both preclinical models and clinical trials.

Neutralizing antibodies against adeno-associated viruses in inflammatory bowel disease patients: implications for gene therapy.

BACKGROUND: Inflammatory bowel diseases (IBDs) are comprised of two major disorders: Crohn's disease (CD) and ulcerative colitis (UC). No curative treatment options are available, but gene therapy may offer an alternative therapeutic approach. For this a safe and reliable vector is needed. The adeno-associated viruses (AAV) have attracted considerable interest as gene therapy vectors. However, neutralizing antibodies (nAb's) made in response to wildtype AAV have been associated with a partial to complete block of transduction in case of reexposure. Therefore, and in order to define AAV vector candidates to treat IBD patients, we characterized preexisting humoral responses to AAV in this population. METHODS: We measured circulating antibodies against AAV serotypes 1, 2, 3, 4, 5, 6, and 8 using a previously established virus neutralization assay. In all, 100 healthy donors and 200 IBD patient's serum samples (101 CD and 99 UC) were analyzed. RESULTS: A significant difference was detected in the prevalence of nAb's for AAV types 1, 5, 6, and 8 between the healthy donors and the patient population. Furthermore, various disease phenotypic characteristics correlated with the prevalence of nAb's to all the serotypes studied. CONCLUSIONS: Our study establishes a foundation for the development of an AAV-based gene therapy approach as a novel treatment for IBD. Furthermore, we show a relationship between disease phenotype in IBD patients and the humoral immune response to AAV.