Updates in therapeutic drug monitoring in inflammatory bowel disease

Biologics and immunomodulators (IMM) are generally considered the most effective therapies for the treatment of ulcerative colitis and Crohn’s disease. However, despite the efficacy of these therapies, many patients either have a primary lack of response or a secondary loss of response to these medications. Therapeutic drug monitoring (TDM) is a systematic approach to managing such patients. In this review, we summarize the latest data on TDM, including reactive and proactive TDM, in patients with inflammatory bowel disease on biologics and/or IMM.     

Real world data on effectiveness,safety and therapeutic drug monitoring of vedolizumab in patients with inflammatory bowel disease. A single center cohort

Background and aims: The efficacy of vedolizumab (VDZ) has been demonstrated in clinical trials. The aim of this report is to evaluate the long-term effectiveness and safety of VDZ in a real-world cohort and to explore possible associations between concentration measurements of VDZ and treatment effectiveness.

Methods: This is a prospective clinical follow-up including all adult patients with ulcerative colitis (UC) and Crohn’s disease (CD) treated with VDZ from October 2014 until September 2017 at a single center in Norway. The patients were followed for at least 14 weeks or until termination of treatment. Clinical and biochemical activity were obtained at every infusion throughout follow-up. Plasma measurements of VDZ (p-VDZ) were performed before every infusion during maintenance therapy.

Results: In total, 71 patients received VDZ. Improvement of CRP and hemoglobin was observed in CD but not in UC, whereas Partial Mayo Score improved in UC while no change in Harvey Bradshaw Index was revealed in CD. Furthermore, CRP at baseline was negatively correlated with p-VDZ at week 14 in CD but not in UC patients.

Conclusion: Improvement of biochemical markers of inflammation was observed in CD while clinical activity scores improved in UC patients. For CD, baseline CRP was correlated with lower concentrations of p-VDZ at week 14.     

Idiopathic acute pancreatitis in patients with inflammatory bowel disease: A multicenter cohort study

BackgroundIdiopathic acute pancreatitis (IAP) in patients with inflammatory bowel disease (IBD) is not well characterized. Our purpose was to better understand this condition and its natural history.MethodsRetrospective cohort study conducted at nine Spanish IBD referral centers. Patients with IBD and a first episode of acute pancreatitis (AP) between 1998 and 2018 were included. Patients with a previous episode of AP or a diagnosis of chronic pancreatitis were excluded. IAP and non-IAP were compared by multivariate logistic regression and survival analysis.ResultsWe identified 185 patients with IBD (68.7% Crohn’s disease) and a first episode of AP. Thirty-eight of those 185 (20.6%) fulfilled criteria for IAP. There were no severe cases of IAP. On multivariate analysis, AP before IBD diagnosis (21.1% vs. 3.4%, p = 0.04) and ulcerative colitis (52.6% vs. 23.1%, p = 0.002) were significantly more common in IAP. Further work-up was performed in 16/38 (42%) IAP patients, and a cause was identified in 6/16 (37.5%). Median time from AP to the end of follow-up was 6.3 years (3.1–10). Five-year risk of AP recurrence was significantly higher in IAP group (28% vs. 5.1%, log-rank p = 0.001), with a median time to first recurrence of 4.4 months (2.9–12.2).ConclusionsIAP represents the second cause of AP in patients with IBD. It is more frequent in ulcerative colitis, and presents a high risk of recurrence. Additional imaging work-up after a first episode of IAP in IBD patients is highly advisable, as it identifies a cause in more than one-third of cases.     

Declining use of combination infliximab and immunomodulator for inflammatory bowel disease in the community setting

AIM To describe trends of combination therapy (CT) of infliximab (IFX) and immunomodulator (IMM) for inflammatory bowel disease(IBD) in the community setting. METHODS A retrospective study was conducted of all IBD patients referred for IFX infusion to our community infusion center between 04/01/01 and 12/31/14. CT was defined as use of IFX with either azathioprine, 6-mercaptopurine, or methotrexate. We analyzed trends of CT usage overall, for Crohn's disease (CD) and ulcerative colitis (UC), and for the subgroups of induction patients. We also analyzed the trends of CT use in these groups over the study period, and compared the rates of CT use prior to and after publication of the landmark SONIC trial.RESULTS Of 258 IBD patients identified during the 12 year study period, 60 (23.3%) received CT, including 35 of 133(26.3%) induction patients. Based on the CochranArmitage trend test, we observed decreasing CT use for IBD patients overall(P 0.0001) and IBD induction patients,(P = 0.0024). Of 154 CD patients, 37(24.68%) had CT, including 20 of 77 (26%) induction patients.The Cochran Armitage test showed a trend towards decreasing CT use for CD overall(P 0.0001) and CD induction,(P = 0.0024). Overall, 43.8% of CD patients received CT pre-SONIC vs 7.4% post-SONIC (P 0.0001). For CD induction, 40.0% received CT preSONIC vs 10.8% post-SONIC(P = 0.0035). Among the 93 patients with UC, 19 (20.4%) received CT. Of 50 induction patients, 14 (28.0%) received CT. The trend test of the 49 patients with a known year of induction again failed to demonstrate any significant trends in the use of CT(P = 0.6). CONCLUSION We observed a trend away from CT use in IBD. A disconnect appears to exist between expert opinion and evidence favoring CT with IFX and IMM, and evolving community practice.     

Impact of the COVID-19 pandemic on inflammatory bowel disease patients: A review of the current evidence

Since the initial coronavirus disease 2019 (COVID-19) outbreak in China in December 2019, the infection has now become the biggest medical issue of modern medicine. Two major contributors that amplified the impact of the disease and subsequently increased the burden on health care systems were high mortality among patients with multiple co-morbidities and overcapacity of intensive care units. Within the gastroenterology-related community, particular concern was raised with respect to patients with inflammatory bowel disease (IBD), as those patients are prone to opportunistic infections mainly owing to their immunosuppressive-based therapies. Hence, we sought to summarize current knowledge regarding COVID-19 infection in patients with IBD. Overall, it seems that IBD is not a comorbidity that poses an increased risk for COVID-19 acquisition, except in patients treated with 5-aminosalicylates. Furthermore, outcomes of the infected patients are largely dependent on therapeutic modality by which they are treated, as some worsen the clinical course of COVID-19 infection, whereas others seem to dampen the detrimental effects of COVID-19. Finally, we discussed the present and the future impact of COVID-19 pandemic and concomitantly increased health care burden on IBD-management.     

Obesity and novel management of inflammatory bowel disease

Obesity is prevalent within the inflammatory bowel disease(IBD) population,particularly in newly developed countries.Several epidemiological studies have suggested that 15%-40% of IBD patients are obese,and there is a potential role of obesity in the pathogenesis of IBD.The dysfunction of mesenteric fat worsens the inflammatory course of Crohn’s disease and may induce formation of strictures or fistulas.Furthermore,obesity may affect the disease course or treatment response of IBD.Given the incr...     

Increased end-stage renal disease risk in patients with inflammatory bowel disease:A nationwide populationbased study

AIM To estimate the risk of end-stage renal disease(ESRD)in patients with inflammatory bowel disease(IBD).METHODS From January 2010 to December 2013, patients with Crohn's disease(CD) and ulcerative colitis(UC) were identified, based on both the International Classification of Diseases, 10 th revision(ICD-10) and the rare,intractable disease registration program codes from the National Health Insurance(NHI) database in South Korea. We compared 38812 patients with IBD to ageand sex-matched non-IBD controls with a ratio of 1:3.Patients newly diagnosed with ESRD were identified with the ICD-10 code.RESULTS During a mean follow-up of 4.9 years, ESRD was detected in 79(0.2%) patients with IBD and 166(0.1%)controls. The incidence of ESRD in patients with IBD was0.42 per 1000 person-years. Patients with IBD had a significantly higher risk of ESRD than controls [adjusted hazard ratio(HR) = 3.03; 95% confidence interval(CI):1.77-5.20; P 0.001]. The incidences(per 1000 personyears)of ESRD were 0.51 in patients with CD and 0.13 in controls, respectively(adjusted HR = 6.33; 95%CI:2.75-14.56; P 0.001). In contrast, the incidence of ESRD was similar between the UC and control groups(0.37 vs 0.37 per 1000 person-years; adjusted HR = 2.01;95%CI: 0.90-4.51; P = 0.089).CONCLUSION The risk of ESRD was elevated in patients with CD, but not UC. Patients with CD should be monitored carefully for signs of renal insufficiency.     

炎症性肠病相关性肝病的研究进展

炎症性肠病(inflammatory bowel disease,IBD)是一种累及回肠、结肠、直肠的特发性炎症性疾病,本病主要包括溃疡性结肠炎(ulcerative colitis,UC)和克罗恩病(Crohn’s disease,CD)。除常见的消化道症状外,研究发现IBD合并肝脏疾病较为常见,是IBD常见的肠外表现之一,其严重影响IBD的预后与转归。本文就IBD相关性肝病的分类和总结作一概述,以期为IBD及其肝脏病变的临床诊疗提供参考。     

Impact of a medical interview on the decision to switch from originator infliximab to its biosimilar in patients with inflammatory bowel disease

BackgroundTo lighten the burden on health-care spending, switching from the infliximab originator to a biosimilar in patients with inflammatory bowel disease (IBD) is advocated. However, the uptake of biosimilars lacks initiatives aimed at educating patients.AimsTo explore the impact of a gastroenterologist’s interview on IBD patients’ acceptance for switching from infliximab bio-originator Remicade® to its biosimilar CT-P13 Inflectra®.MethodsAfter the interview of 138 included patients, 120 properly responded to a self-administered questionnaire to collect consent about the switch and relevant data. French national IBD patients’ association (Association François Aupetit) provided an information sheet on biosimilars.Results93 (67.0%) out of 138 and 82 (68.3%) out of 120 patients switched treatment. 114 (79.8%) had never heard about biosimilars. Paradoxically, having heard about biosimilars was associated with a poorer chance to switch (Odds Ratio OR [95% CI] = 0.13 [0.02–0.72]). On the contrary, the more satisfied about generics, the more patients accepted the switch (OR [95% CI] = 1.31 [1.01–1.69]). There were 1.47 (Relative Risk RR [95% CI] = 1.47 [1.07–2.01]) times more chance to agree to the switch if the interview modified the patient’s opinion on biosimilars.ConclusionThis study confirms that an organized information provided to the patient is a contributive way to enhance patient’s acceptance of biosimilars in IBD.     

Real-world treatment patterns and disease control over one year in patients with inflammatory bowel disease in Brazil

BACKGROUNDCrohn’s disease (CD) and ulcerative colitis (UC) are inflammatory bowel diseases (IBDs) with a remission-relapsing presentation and symptomatic exacerbations that have detrimental impacts on patient quality of life and are associated with a high cost burden, especially in patients with moderate-to-severe disease. The Real-world Data of Moderate-to-Severe Inflammatory Bowel Disease in Brazil (RISE BR) study was a noninterventional study designed to evaluate disease control, treatment patterns, disease burden and health-related quality of life in patients with moderate-to-severe active IBD. We report findings from the prospective follow-up phase of the RISE BR study in patients with active UC or CD.AIMTo describe the 12-mo disease evolution and treatment patterns among patients with active moderate-to-severe IBD in Brazil.METHODSThis was a prospective, noninterventional study of adult patients with active Crohn’s disease (CD: Harvey-Bradshaw Index ≥ 8, CD Activity Index ≥ 220), inadequate CD control (i.e., calprotectin > 200 µg/g or colonoscopy previous results), or active ulcerative colitis (UC: Partial Mayo score ≥ 5). Enrollment occurred in 14 centers from October 2016 to February 2017. The proportion of active IBD patients after 9-12 mo of follow-up, Kaplan-Meier estimates of the time to mild or no activity and a summary of treatment initiation, discontinuation and dose changes were examined.RESULTSThe study included 118 CD and 36 UC patients, with mean ± SD ages of 43.3 ± 12.6 and 44.9 ± 16.5 years, respectively. The most frequent drug classes at index were biologics for CD (62.7%) and 5-aminosalicylate derivates for UC patients (91.7%). During follow-up, 65.3% of CD and 86.1% of UC patients initiated a new treatment at least once. Discontinuations/dose changes occurred in 68.1% of CD patients [median 2.0 (IQR: 2-5)] and 94.3% of UC patients [median 4.0 (IQR: 3-7)]. On average, CD and UC patients had 4.4 ± 2.6 and 5.0 ± 3.3 outpatient visits, respectively. The median time to first mild or no activity was 319 (IQR: 239-358) d for CD and 320 (IQR: 288-358) d for UC patients. At 9-12 mo, 22.0% of CD and 20.0% of UC patients had active disease.CONCLUSIONAlthough a marked proportion of active IBD patients achieved disease control within one year, the considerable time to achieve this outcome represents an unmet medical need of the current standard of care in a Brazilian real-world setting.     

Anemia at the time of diagnosis of inflammatory bowel disease: Prevalence and associated factors in adolescent and adult patients

BackgroundThe prevalence, characteristic and determinants of anemia, at the time of inflammatory bowel disease (IBD) diagnosis have yet to be fully elucidated.MethodsRetrospective cross-sectional study. Analytical data and disease characteristics obtained upon diagnosis of 1278 IBD patients [Crohn’s disease/ulcerative colitis (CD/UC): 718/560] were collected.ResultsAnemia was present in 41.2% of patients at diagnosis (47% and 33.8% of CD and UC patients, respectively; p < 0.001), being severe in 5.5%. Iron deficiency anemia represented 69.6% of cases, with no differences between CD and UC. Female sex was the strongest risk factor for anemia in both CD and UC (OR 7.11; 95%CI 4.18–12.10 and 6.55; 95%CI 3.39–12.63, respectively), followed by elevated (≥2 mg/dL) C-reactive protein (OR 4.08; 95%CI 2.39–6.97 and 4.58; 95%CI 2.26–9.27, respectively). Current smoking was a risk factor for anemia in CD (OR 2.23; 95%CI 1.24–4.02), but a protective one in UC (OR 0.36; 95%CI 0.14–0.92). A penetrating CD behavior increased the risk of anemia (OR 3.34; 95%CI 1.36–8.21); in UC, anemia increased with disease extension (E2 + E3) (OR 1.80; 95%CI 1.13–2.86).ConclusionsFemale sex and disease activity are major determinants of anemia at IBD diagnosis. Anemia is associated with disease behavior in CD and with disease extension in UC.     

Inflammatory bowel disease patients are frequently nonadherent to scheduled induction and maintenance infliximab therapy: A Canadian cohort study

BACKGROUND:

Adherence to maintenance medication regimens in inflammatory bowel disease patients has traditionally been poor. Although infliximab has demonstrated efficacy in inducing and maintaining disease remission, adherence to regularly scheduled infliximab infusions is required to maintain therapeutic trough drug levels and prevent the development of anti-infliximab antibodies.

OBJECTIVES:

To characterize patient adherence to regularly scheduled induction and maintenance infliximab infusions.

METHODS:

A retrospective cohort study was conducted evaluating adult outpatients with Crohn disease or ulcerative colitis on an induction or maintenance regimen of regularly scheduled infliximab from 2008 to 2010 at the University of Alberta (Edmonton, Alberta). Nonadherence was defined by a discrepancy of >72 h between the scheduled date of infusion and the actual date of administration. Patients were defined as nonadherent if they received <80% of their infliximab infusions per schedule.

RESULTS:

A total of 215 patients (173 Crohn disease, 42 ulcerative colitis) met the inclusion criteria. Patients received a median of 12.0 infliximab infusions (interquartile range 7.0 to 13.0) during the study period; 412 induction and 1837 maintenance infliximab infusions were administered. Of 140 patients, 109 (77.9%) were adherent to their infliximab induction regimen, while 68 of 215 (31.6%) were adherent to their infliximab maintenance regimen. One hundred ninety-eight of 215 (92.1%) patients received at least one delayed maintenance infliximab infusion and 20 (10.1%) received maintenance infusions, on average, >1 week late.

CONCLUSIONS:

While three-quarters of patients are adherent to infliximab induction therapy, fewer than one-third remained adherent to their scheduled maintenance infliximab regimen.     

Predicting(side) effects for patients with inflammatory bowel disease: The promise of pharmacogenetics

Inflammatory bowel disease (IBD) is a chronic and heterogeneous intestinal inflammatory disorder. The medical management of IBD aims for long-lasting disease remission to prevent complications and disease progression. Early introduction of immunosuppression forms the mainstay of medical IBD management. Large inter-individual variability in drug responses, in terms of both efficacy and toxicity, leads to high rates of therapeutic failure in the management of IBD. Better patient stratification is needed to maximize patient benefit and minimize the harm caused by adverse events. Pre-treatment pharmacogenetic testing has the potential to optimize drug selection and dose, and to minimize harm caused by adverse drug reactions. In addition, optimizing the use of cheap conventional drugs, and avoiding expensive ineffective drugs, will lead to a significant reduction in costs. Genetic variation in both TPMT and NUDT15, genes involved in thiopurine metabolism, is associated to an increased risk of thiopurine-induced myelosuppression. Moreover, specific HLA haplotypes confer risk to thiopurine-induced pancreatitis and to immunogenicity to tumor necrosis factor-antagonists, respectively. Falling costs and increased availability of genetic tests allow for the incorporation of pre-treatment genetic tests into clinical IBD management guidelines. In this paper, we review clinically useful pharmacogenetic associations for individualized treatment of patients with IBD and discuss the path from identification of a predictive pharmacogenetic marker to implementation into IBD clinical care.     

Risk of inflammatory bowel disease in patients with chronic obstructive pulmonary disease: A nationwide,population-based study

BACKGROUND There is a growing evidence regarding an increased risk of inflammatory bowel disease(IBD) among patients with airway diseases.AIM To investigate the influence of chronic obstructive pulmonary disease(COPD) on the risk of IBD.METHODS A nationwide, population-based study was conducted using data from the National Health Insurance Service database. A total of 1303021 patients with COPD and 6515105 non-COPD controls were identified. The COPD group was divided into the severe and the mild COPD group according to diagnostic criteria. The risk of IBD in patients with COPD compared to controls was analyzed by Cox proportional hazard regression models. The cumulativeincidences of IBD were compared between the groups.RESULTS The COPD group had higher incidences of IBD compared to non-COPD controls(incidence rate, 9.98 vs 7.18 per 100000 person-years, P 0.001). The risk of IBD in the COPD group was increased by 1.38(adjusted hazard ratio(HR); 95%CI: 1.25-1.52). The incidence rate of IBD was higher in the severe COPD group than in the mild COPD group(12.39 vs 9.77 per 100000 person-year, P 0.001). The severity of COPD was associated with an increased risk of IBD(adjusted HR 1.70 in severe COPD, 95%CI: 1.27-2.21 and adjusted HR 1.35 in mild COPD, 95%CI: 1.22-1.49)CONCLUSION The incidences of IBD were significantly increased in COPD patients in South Korea and the risk of developing IBD also increased as the severity of COPD increased.     

Epidemiology of inflammatory bowel disease in South America: A systematic review

BACKGROUND The worldwide epidemiology of inflammatory bowel disease(IBD) is rapidly changing. Increasing Crohn's disease(CD) and ulcerative colitis(UC) incidence and prevalence have been recorded in developing regions such as Asia, Africa and Eastern Europe where it was previously thought to be uncommon. Whether this is also the case in South America is not well known. Demonstration that developing regions worldwide have increasing IBD incidence would indicate that environmental change plays a significant role in the development of IBD.AIM To report the incidence, prevalence and disease characteristics of CD and UC within the South American continent.METHODS A systematic review was conducted by searching published studies in major international and regional databases(MEDLINE, EMBASE and Scopus) between January 1990 and December 2018. Outcomes considered were incidence,prevalence, phenotype, environmental and genetic factors, ethnicity and gender.A pair of independent reviewers screened and reviewed all identified articles.RESULTS One hundred and sixty two citations were initially retrieved with 18 studies included in this systematic review. The majority of included studies were from Brazil(n =13, 72%). The incidence of UC ranged from 4.3-5.3/100000 personyears whilst the incidence of CD ranged from 0.74-3.5/100000 person-years.Prevalence ranged from 15.0-24.1/100000 inhabitants for UC and from 2.4-14.1/100000 inhabitants for CD. The incidence and prevalence of both UC and CD has increased significantly in Brazil over the past 21 years. Pancolitis was the most common disease distribution in patients with UC whilst colonic involvement was the most common distribution in CD. People residing in urbanareas were at higher risk of developing both CD and UC.CONCLUSION The IBD burden in South America is increasing at a rate possibly even greater than other developing regions around the world. There is a paucity of highquality epidemiological studies and further robust and representative data are required to further explore modifiable risk factors and disease phenotypes.     

Emerging therapeutic options in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disease that requires chronic treatment throughout the evolution of the disease, with a complex physiopathology that entails great challenges for the development of new and specific treatments for ulcerative colitis and Crohn´s disease. The anti-tumor necrosis factor alpha therapy has impacted the clinical course of IBD in those patients who do not respond to conventional treatment, so there is a need to develop new therapies and markers of treatment response. Various pathways involved in the development of the disease are known and the new therapies have focused on blocking the inflammatory process at the gastrointestinal level by oral, intravenous, subcutaneous, and topical route. All these new therapies can lead to more personalized treatments with higher success rates and fewer relapses. These treatments have not only focused on clinical remission, but also on achieving macroscopic changes at the endoscopic level and microscopic changes by achieving mucosal healing. These treatments are mainly based on modifying signaling pathways, by blocking receptors or ligands, reducing cell migration and maintaining the integrity of the epithelial barrier. Therefore, this review presents the efficacy and safety of the new treatments that are currently under study and the advances that have been made in this area in recent years.     

Urotensin II levels in patients with inflammatory bowel disease

BACKGROUNDPatients with inflammatory bowel disease (IBD) are associated with increased cardiovascular risk and have increased overall cardiovascular burden. On the other hand, urotensin II (UII) is one of the most potent vascular constrictors with immunomodulatory effect that is connected with a number of different cardiometabolic disorders as well. Furthermore, patients with ulcerative colitis have shown increased expression of urotensin II receptor in comparison to healthy controls. Since the features of IBD includes chronic inflammation and endothelial dysfunction as well, it is plausible to assume that there is connection between increased cardiac risk in IBD and UII.AIMTo determine serum UII levels in patients with IBD and to compare them to control subjects, as well as investigate possible associations with relevant clinical and biochemical parameters.METHODSThis cross sectional study consecutively enrolled 50 adult IBD patients (26 with Crohn’s disease and 24 with ulcerative colitis) and 50 age and gender matched controls. Clinical assessment was performed by the same experienced gastroenterologist according to the latest guidelines. Ulcerative Colitis Endoscopic Index of Severity and Simple Endoscopic Score for Crohn’s Disease were used for endoscopic evaluation. Serum levels of UII were determined using the enzyme immunoassay kit for human UII, according to the manufacturer’s instructions.RESULTSIBD patients have significantly higher concentrations of UII when compared to control subjects (7.57 ± 1.41 vs 1.98 ± 0.69 ng/mL, P < 0.001), while there were no significant differences between Crohn’s disease and ulcerative colitis patients (7.49 ± 1.42 vs 7.65 ± 1.41 ng/mL, P = 0.689). There was a significant positive correlation between serum UII levels and high sensitivity C reactive peptide levels (r = 0.491, P < 0.001) and a significant negative correlation between serum UII levels and total proteins (r = -0.306, P = 0.032). Additionally, there was a significant positive correlation between serum UII levels with both systolic (r = 0.387, P = 0.005) and diastolic (r = 0.352, P = 0.012) blood pressure. Moreover, serum UII levels had a significant positive correlation with Ulcerative Colitis Endoscopic Index of Severity (r = 0.425, P = 0.048) and Simple Endoscopic Score for Crohn’s Disease (r = 0.466, P = 0.028) scores. Multiple linear regression analysis showed that serum UII levels retained significant association with high sensitivity C reactive peptide (β ± standard error, 0.262 ± 0.076, P < 0.001) and systolic blood pressure (0.040 ± 0.017, P = 0.030).CONCLUSIONIt is possible that UII is involved in the complex pathophysiology of cardiovascular complications in IBD patients, and its purpose should be investigated in further studies.     

Anti-pancreatic antibody in Turkish patients with inflammatory bowel disease and first-degree relatives

AIM: To identify the role of anti-pancreatic antibody (PAB) in the diagnosis of inflammatory bowel diseases (IBD) among Turkish patients, and its frequency in firstdegree relatives.METHODS: PAB and anti-Saccharomyces cerevisiae (ASCA) were examined in serum samples of 214 subjects including patients with Crohn’s disease (CD, n = 64), ulcerative colitis (UC, n = 63), first-degree relatives of patients with CD (n = 25), first-degree relatives of patients with UC (n = 28),and a control group with gastrointestinal symptoms other than (IBD) (n = 34) by indirect immunofluorescence Positivity of PAB and ASCA was compared in terms of Vienna classification, disease activity and medications used.RESULTS: In terms of PAB positivity, no difference was found between patients with CD (14.1%) and UC (7.9%) however, significant difference was observed between patients with CD and subjects in the control group (P < 0.05). No difference was found between patients with CD and their relatives in terms of ASCA positivity, whereas a significant difference was found between other groups (P < 0.001). Compared to ASCA, the sensitivity of the PAB was 19% (7/37), its specificity was 93% (25/27), positive predictive value was 77% (7/9) and negative predictive value was 45% (25/55). ASCA was found with significantly higher prevalence in patients with CD activity index > 150 (P < 0.05).CONCLUSION: PAB is valuable in the diagnosis of IBD rather than CD, but cannot be used alone for diagnostic purposes. PAB is not superior to ASCA in CD diagnosis and in detecting CD among relatives of patients with CD.