Diagnosis and Treatment of Latent Tuberculosis Infection in Patients with Inflammatory Bowel Diseases due to Initiation of Anti-Tumor Necrosis Factor Therapy

Risk of tuberculosis with anti-TNF therapy in Indian patients with inflammatory bowel disease despite negative screening

BACKGROUND AND STUDY AIMS

Tuberculosis (TB) is a well-recognized adverse effect associated with using biological therapy to manage various autoimmune conditions. There is a dearth of information about the development of TB after using anti-TNF agents in patients with inflammatory bowel disease (IBD) from TB-endemic countries like India. This study aimed to estimate the risk of TB and its predictors after treatment with anti-TNF agents in patients with IBD.

PATIENTS AND METHODS

The present study is a retrospective analysis of data of patients with IBD from two tertiary care centers in India receiving anti-TNF therapy. Patients who had undergone chest X-ray, high-resolution computed tomography of the chest, and tuberculin skin test, with a follow-up duration of at least 6 months, were included in the analysis.

RESULTS

In this multi-center study, 95 patients on anti-TNF agents for IBD (Median age of onset: 27 years, 62.1 % males) were followed up for a median duration of 9 (6-142) months. Among patients with IBD, 79 (83.2 %) had Crohn's disease, and 16 (16.8 %) had ulcerative colitis. Infliximab was the commonest biological, used in 82.1 % of cases, followed by adalimumab (17.9 %). On follow-up, 8.4 % (8/95) of the patients developed TB, among which the majority had extrapulmonary tuberculosis (5/8). On multivariate analysis, the duration of biological (Odds ratio: 1.047, 95 % confidence interval 1.020-1.075; p = 0.001) use was the only independent predictor of the development of TB with biologicals.

CONCLUSION

Among Indian patients with IBD, there is a high risk of TB with anti-TNF agents, which increases with the duration of therapy. The current methods for latent TB screening in Indians are ineffective, and predicting TB after initiating biological therapy is difficult.

Tumor Necrosis Alpha (TNF-α) Antagonists Used in Chronic Inflammatory Rheumatic Diseases: Risks and their Minimization Measures

Tumor necrosis factor alpha (TNF- α) inhibitors are widely employed for the management of chronic inflammatory rheumatism. However, their usage carries significant risks, including site and infusion reactions, serious infections, malignancy, heart failure autoimmune and demyelinating disorders. These risks are comprehensively outlined in risk management plans (RMPs) associated with these molecules. RMP provides information on the safety profile of a medicinal product as well as the measures that will be taken to minimize risks; these are known as risk minimization measures. These measures are divided into routine measures related to elements, such as the summary of product characteristics, labeling, pack size, package leaflet, or legal supply status of the product, while additional measures may include educational programs, including tools for healthcare providers and patients, controlled access or pregnancy prevention programs, among others. Additional measures can consist of one or more interventions that need to be implemented in a sustainable way in a defined target group, while respecting the timing and frequency of any intervention and procedures to reach the target population. An evaluation of the effectiveness of these measures is required to determine whether or not an intervention has been effective. This comprehensive review offers an in-depth exploration of the current treatment, uses, and associated risks of TNF-α inhibitors. Additionally, it provides a detailed account of risk minimization measures and risk management practices while shedding light on their real-world implementation and effectiveness.

Screening of latent tuberculosis infection among patients with diabetes mellitus from a high-burden area in Brazil

Although several cohort studies have raised the important association between diabetes mellitus (DM) and latent tuberculosis infection (LTBI), evidences are limited and controversial. Furthermore, it is well documented that the poor glycemic control may exacerbate the risk for active TB. Thus, the monitoring of diabetic patients living in high-incidence areas for TB is an important concern in views of available diagnostic tests for LTBI. In this cross-sectional study, we estimate the association of DM and LTBI among diabetic patients classified as type-1 DM (T1D) or type-2 DM (T2D) living in Rio de Janeiro, RJ, Brazil - considered a high TB burden region of these country. Non-DM volunteers were included as endemic area healthy controls. All participants were screened for DM using glycosylated-hemoglobin (HbA_1c) and for LTBI using the QuantiFERON-TB Gold in Tube (QFT-GIT). Demographic, socioeconomic, clinical and laboratorial data were also assessed. Among 553 included participants, 88 (15.9%) had QFT-GIT positive test, of which 18 (20.5%) were non-DM, 30 (34.1%) T1D and 40 (45.4%) T2D. After adjustments for potential baseline confounders, age, self-reported non-white skin color and an active TB case in the family were significantly associated with LTBI among the studied population by using a hierarchical multivariate logistic regression analysis. Additionally, we verified that T2D patients were able to produce significant increased interferon-gamma (IFN-γ) plasma levels in response to Mycobacterium tuberculosis-specific antigens, when compared to non-DM individuals. Altogether, our data showed an increased prevalence of LTBI among DM patients, albeit non-statistically significant, and point out to important independent factors associated with LTBI, which deserve attention in monitoring patients with DM. Moreover, QFT-GIT test seems to be a good tool to screening LTBI in this population, even in a high TB burden area.

Risk and characteristics of tuberculosis after anti-tumor necrosis factor therapy for inflammatory bowel disease: a hospital-based cohort study from Korea

BACKGROUND

Anti-tumor necrosis factor (TNF) treatment for inflammatory bowel disease (IBD) increases the risk of tuberculosis (TB) infection. In the present study, we analyzed the clinical characteristics and risks of TB in Korean patients with IBD who received anti-TNF treatment.

METHODS

The study included patients with IBD who were treated using anti-TNF agents between January 2001 and June 2018 at the Asan Medical Center. Overall, 1434 patients with ulcerative colitis or Crohn's disease were enrolled. We calculated the incidence of active TB infection after anti-TNF treatment and compared the clinical characteristics of the TB group with those of the non-TB group.

RESULTS

Twenty-one patients (1.46%) developed active TB infection, and the incidence rate of active TB was 366.73 per 100,000 person-years. In total, 198 patients (14.9%) were positive for latent tuberculosis infection (LTBI), of whom only eight (4%) did not complete LTBI treatment. The age at which the anti-TNF therapy was started was significantly higher in the TB group than in the non-TB group (HR 1.041, 95% CI 1.014-1.069, p = 0.002), and as age increased, so did the incidence rate of active TB infection (linearity p < 0.001). There was no significant difference in the incidence rate of LTBI between the TB and non-TB groups (HR 0.896, 95% CI 0.262-3.066, p = 0.862).

CONCLUSIONS

In patients with IBD, the incidence rate of TB increased with age at anti-TNF therapy initiation. Active treatment of LTBI may lower the incidence of TB in patients with IBD who are to undergo anti-TNF therapy.

Pulmonary Tuberculosis After Therapy with Anti-Tumor Necrosis Factor (TNF) for Crohn Disease: A Case Report

Patient: Male, 38-year-old

Final Diagnosis: Crohn’s disease • pulmonary tuberculosis

Symptoms: Abdominal pain • bloody bowel movements • diarrhea • dry cough • fever • hyporexia • malaise • weight loss

Medication: —

Clinical Procedure: —

Specialty: Gastroenterology and Hepatology

Comparison of Interferon-Gamma Release Assay and Tuberculin Skin Test for the Screening of Latent Tuberculosis in Inflammatory Bowel Disease Patients: Indian Scenario

Background

In a country like India, where the prevalence of tuberculosis is very high, the role of screening tools for detection of latent tuberculosis infection (LTBI) like TST and IGRA is still unclear, especially in inflammatory bowel disease (IBD) patients. Our study is aimed at comparing the interferon-gamma release assay (IGRA) and tuberculin skin test (TST) to determine the prevalence of LTBI in IBD patients in the Indian subset of the population.

Methods

It was a prospective observational analysis. A total of 257 participants were included in the study. Both TST and IGRA were performed in consecutive patients diagnosed with IBD (131 patients) and in 126 healthy individuals. Both tests were performed on the same day. LTBI diagnosis was considered if any one of TST or IGRA was found to be positive.

Results

Out of 131 IBD patients, 121 patients had ulcerative colitis and 10 patients had Crohn's disease. 29% of the IBD patients and 22% of the control subjects had LTBI. The study demonstrated concordance between TST and IGRA. Agreement test kappa value for IBD patients was 0.656 (CI 0.50-0.81), with a p value of <0.001, suggestive of a fair agreement. Mean IFN-γ release was lower in the immunosuppressed group as compared to non-immunosuppressed individuals (0.26 ± 0.17 vs. 0.45 ± 0.07, p = 0.02). Cohen's kappa coefficient values in IBD cases and control subjects were 0.66 and 0.79, respectively. TST was found to be negatively correlated to BMI.

Conclusion

Agreement between TST and IGRA was fair in IBD patients. For LTBI screening in IBD patients, TST and IGRA are complementary methods.

Risk stratification and management of QuantiFERON-positive solid-organ living donors

PURPOSE OF REVIEW

Donor-derived disease with Mycobacterium tuberculosis (MTB) is likely to become more common as donor pools expand due to increasing transplant volume coupled with patterns of migration and global mobility. Our article reviews the current literature and provides a rational approach for clinicians managing the scenario of a living donor who has epidemiologic risk factors for tuberculosis exposure.

RECENT FINDINGS

Tuberculous bacilli, formerly thought to exist latently only in pulmonary granulomas, are now known reside dormant in nonpulmonary organs. Kidney and liver grafts are thus vectors for donor transmitted MTB disease. Donors with elevated risk for latent MTB disease can be identified with tuberculin skin testing or IFN-γ release assay screening in combination with a thorough history to identify risk factors for latent disease.

SUMMARY

Living donors with an elevated risk for prior MTB exposure provide an opportunity to treat latent disease prior to organ procurement and reduce the risk of donor transmitted disease and secondary morbidity. Improved identification of these high-risk donors can reduce both the incidence of posttransplant MTB disease and the risk of allograft compromise associated with treatment of latent and active disease in posttransplant recipients.

Asian Organization for Crohn's and Colitis and Asia Pacific Association of Gastroenterology consensus on tuberculosis infection in patients with inflammatory bowel disease receiving anti-tumor necrosis factor treatment. Part 1: risk assessment

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection and prevention of latent TB infection, and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from 9 Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 1 of the statements comprised 2 parts: risk of TB infection Recommendaduring anti-TNF therapy, and screening for TB infection prior to commencing anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment.

Asian Organization for Crohn's and Colitis and Asia Pacific Association of Gastroenterology consensus on tuberculosis infection in patients with inflammatory bowel disease receiving anti-tumor necrosis factor treatment. Part 2: management

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection and prevention of latent TB infection, and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from 9 Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 2 of the statements comprised 3 parts: management of latent TB in preparation for anti-TNF therapy, monitoring during anti-TNF therapy, and management of an active TB infection after anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment.

Asian Organization for Crohn's and Colitis and Asian Pacific Association of Gastroenterology consensus on tuberculosis infection in patients with inflammatory bowel disease receiving anti-tumor necrosis factor treatment. Part 1: Risk assessment

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asian Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection, and prevention of latent TB infection and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from nine Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 1 of the statements comprised two parts: (i) risk of TB infection during anti-TNF therapy and (ii) screening for TB infection prior to commencing anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment.

Asian Organization for Crohn's and Colitis and Asia Pacific Association of Gastroenterology consensus on tuberculosis infection in patients with inflammatory bowel disease receiving anti-tumor necrosis factor treatment. Part 2: Management

Because anti-tumor necrosis factor (anti-TNF) therapy has become increasingly popular in many Asian countries, the risk of developing active tuberculosis (TB) among anti-TNF users may raise serious health problems in this region. Thus, the Asian Organization for Crohn's and Colitis and the Asia Pacific Association of Gastroenterology have developed a set of consensus statements about risk assessment, detection and prevention of latent TB infection, and management of active TB infection in patients with inflammatory bowel disease (IBD) receiving anti-TNF treatment. Twenty-three consensus statements were initially drafted and then discussed by the committee members. The quality of evidence and the strength of recommendations were assessed by using the Grading of Recommendations Assessment, Development, and Evaluation methodology. Web-based consensus voting was performed by 211 IBD specialists from nine Asian countries concerning each statement. A consensus statement was accepted if at least 75% of the participants agreed. Part 2 of the statements comprised three parts: (3) management of latent TB in preparation for anti-TNF therapy, (4) monitoring during anti-TNF therapy, and (5) management of an active TB infection after anti-TNF therapy. These consensus statements will help clinicians optimize patient outcomes by reducing the morbidity and mortality related to TB infections in patients with IBD receiving anti-TNF treatment.

Serial Tuberculosis Screening in Inflammatory Bowel Disease Patients Receiving Anti-TNFα Therapy

BACKGROUND AND AIMS

One of the adverse effects of the tumour necrosis factor alpha [[TNFα] monoclonal antibodies for the treatment of immune-mediated inflammatory diseases is a higher propensity for tuberculosis development. The aim of this study was to explore the utility and sensitivity of serial tuberculosis screening during anti-TNFα treatment.

METHODS

A cohort of 46 inflammatory bowel disease patients receiving infliximab was prospectively recruited and followed for 26 months. During this period of time, a tuberculosis skin test and two different interferon ϒ release assays [QFT-GIT and T-SPOT.TB] were applied at 4-6-month intervals.

RESULTS

Overall, 16 patients were diagnosed with latent tuberculosis infection after having at least one test conversion: 12 patients had a positive tuberculosis skin test, seven patients had a positive T-SPOT.TB, and two patients had a positive QFT-GIT. Active tuberculosis was excluded in all; 15 were treated with isoniazid. A comparison between tests showed a moderate accuracy [72% to 85%] but low kappa values [0.063 to 0.377]. Concerning association with demographic and clinical characteristics, test conversion was more common among the male gender and those with a longer disease duration.

CONCLUSIONS

Tuberculosis tests conversions were common in inflammatory bowel disease patients treated with infliximab alone or in association with immunomodulators. In these immunosuppressed individuals, the classical tuberculosis skin test seems to have a higher sensitivity than the modern tests based on the release of interferonϒ.

Decreased CD8+CD28+/CD8+CD28- T cell ratio can sensitively predict poor outcome for patients with complicated Crohn disease

Crohn disease (CD) with complications such as penetrating, stricturing, and perianal disease is called complicated CD. The aim of this study is to test the efficiency with which the CD8CD28/CD8CD28 cell balance can predict a subsequent active stage in patients with newly diagnosed complicated CD.Seventeen patients with complicated CD and 48 CD patients with no complications were enrolled. Blood CD8 T cells were tested from all of the 65 newly diagnosed CD patients upon enrollment. The potential risk factors were compared between the 2 groups. A 30-week follow-up was performed, and the efficiency of the CD8 cell balance at predicting active CD was analyzed using receiver-operating characteristic curves. The cumulative remission lasting rates (CRLRs) were analyzed using the Kaplan-Meier method.Compared with the control CD group, patients with complicated CD were predominantly male and younger in age; they also had lower body mass indices (BMIs), higher Crohn disease activity indices (CDAIs), higher immunosuppressant and steroid prescription rates, and significantly higher surgical rates. The CD8CD28/CD8CD28 balance was associated with BMI, CDAI, steroids, and surgery. The CD8CD28/CD8CD28 ratios were significantly lower at week 0 and on the 6th, 22nd, and 30th week during follow-up with a shorter lasting time of remission for the complicated CD patients. The CD8CD28/CD8CD28 ratio could accurately predict the active stage for the patients with complicated CD, and the highest sensitivity (89.2%) and specificity (85.3%) were found when the ratio was 1.03. Treatment with steroids and surgery, along with a significantly lower CD8CD28/CD8CD28 ratio and lower CRLRs, was closely related to a worse outcome for the patients with complicated CD.Patients requiring steroids and surgery experience more severe disease activity and thus a disequilibrated immunological balance, which could be the main reason for a decreased CD8CD28/CD8CD28 ratio. This ratio can sensitively predict the active stage for patients with complicated CD, and more care should be taken when this ratio is <1.03.

Differences in Clinical Manifestations according to the Positivity of Interferon-γ Assay in Patients with Intestinal Tuberculosis

Intestinal tuberculosis (ITB) remains prevalent in Asia. An interferon-γ assay (QuantiFERON-TB gold test [QFT]) is considered to be an effective supplementary tool for diagnosing ITB. We retrospectively analyzed the clinical features of ITB patients based on the initial results of QFT. A total of 109 patients with ITB were enrolled, and 82 patients (75.2%) showed positive QFT results. In the QFT-positive group, the mean age (44.1±12.0 years) was significantly higher than that in the QFT-negative group (37.0±14.8, p=0.0096). Abdominal pain (p=0.006) and diarrhea (p=0.030) were more frequent in the QFT-negative group. Further, C-reactive protein (CRP) levels were significantly higher in the QFT-negative group (6.4±9.9 mg/dL) than in the QFT-positive group (1.3±2.3, p<0.001). Multivariate analysis confirmed that younger age (p=0.016), diarrhea (p=0.042), and high levels of CRP (p=0.029) were independent predictors of QFT-negative results in patients with ITB. These results suggest that prior exposure to TB, reflected by QFT positivity, may cause mild inflammation in patients with ITB.

[Second Korean Guideline for the Management of Ulcerative Colitis]

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder characterized by a relapsing and remitting course. The direct and indirect costs of the treatment of UC are high, and the quality of life of patients is reduced, especially during exacerbation of the disease. The incidence and prevalence of UC in Korea are still lower than those of Western countries, but have been rapidly increasing during the past decades. Various medical and surgical therapies, including biologics, are currently used for the management of UC. However, many challenging issues exist, which sometimes lead to differences in practice between clinicians. Therefore, the Inflammatory Bowel Disease Study Group of the Korean Association for the Study of Intestinal Diseases established the first Korean guideline for the management of UC in 2012. This is an update of the first guideline. It was generally made by the adaptation of several foreign guidelines as was the first edition, and encompasses treatment of active colitis, maintenance of remission, and indication of surgery for UC. The specific recommendations are presented with the quality of evidence and classification of recommendations.

Second Korean guidelines for the management of ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by a relapsing and remitting course. The direct and indirect costs of the treatment of UC are high, and the quality of life of patients is reduced, especially during exacerbation of the disease. The incidence and prevalence of UC in Korea are still lower than those of Western countries, but have been rapidly increasing during the past decades. Various medical and surgical therapies, including biologics, are currently used for the management of UC. However, many challenging issues exist, which sometimes lead to differences in practice between clinicians. Therefore, the IBD study group of the Korean Association for the Study of Intestinal Diseases established the first Korean guidelines for the management of UC in 2012. This is an update of the first guidelines. It was generally made by the adaptation of several foreign guidelines as was the first edition, and encompasses treatment of active colitis, maintenance of remission, and indication of surgery for UC. The specific recommendations are presented with the quality of evidence and classification of recommendations.

Efficacy and Safety of Infliximab Therapy and Predictors of Response in Korean Patients with Crohn's Disease: A Nationwide, Multicenter Study

PURPOSE

Infliximab is currently used for the treatment of active Crohn's disease (CD). We aimed to assess the efficacy and safety of infliximab therapy and to determine the predictors of response in Korean patients with CD.

MATERIALS AND METHODS

A total of 317 patients who received at least one infliximab infusion for active luminal CD (n=198) and fistulizing CD (n=86) or both (n=33) were reviewed retrospectively in 29 Korean referral centers. Clinical outcomes of induction and maintenance therapy with infliximab, predictors of response, and adverse events were evaluated.

RESULTS

In patients with luminal CD, the rates of clinical response and remission at week 14 were 89.2% and 60.0%, respectively. Male gender and isolated colonic disease were associated with higher remission rates at week 14. In week-14 responders, the probabilities of sustained response and remission were 96.2% and 93.3% at week 30 and 88.0% and 77.0% at week 54, respectively. In patients with fistulizing CD, clinical response and remission were observed in 85.0% and 56.2% of patients, respectively, at week 14. In week-14 responders, the probabilities of sustained response and remission were 94.0% and 97.1%, respectively, at both week 30 and week 54. Thirty-nine patients (12.3%) experienced adverse events related to infliximab. Serious adverse events developed in 19 (6.0%) patients including seven cases of active pulmonary tuberculosis.

CONCLUSION

Infliximab induction and maintenance therapy are effective and well tolerable in Korean patients with luminal and fistulizing CD. However, clinicians must be aware of the risk of rare yet critical adverse events.

Rectal tuberculosis after infliximab therapy despite negative screening for latent tuberculosis in a patient with ulcerative colitis

Tumor necrosis factor-α inhibitors are now considered as standard therapy for patients with severe inflammatory bowel disease who do not respond to corticosteroids, but they carry a definite risk of reactivation of tuberculosis. We present a case in which a patient with inflammatory bowel disease developed a de novo tuberculosis infection after the start of anti-tumor necrosis factor-α treatment despite showing negative results in tuberculosis screening. Although there are many case reports of pleural, lymph nodal and disseminated tuberculosis following infliximab therapy, we present the first case report of rectal tuberculosis following infliximab therapy.

Clinical features of active tuberculosis that developed during anti-tumor necrosis factor therapy in patients with inflammatory bowel disease

Background/Aims

Anti-tumor necrosis factor (TNF) therapy for active ulcerative colitis (UC) and Crohn's disease (CD) is associated with increased risks of tuberculosis (TB) infection. We analyzed the incidence and clinical features of Korean patients with inflammatory bowel disease (IBD) who developed active TB during anti-TNF therapy.

Methods

Ten cases of active TB developed in patients treated with infliximab (n=592) or adalimumab (n=229) for UC (n=160) or CD (n=661) were reviewed. We analyzed demographics, interval between start of anti-TNF therapy and active TB development, tests for latent TB infection (LTBI), concomitant medications, and the details of diagnosis and treatments for TB.

Results

The incidence of active TB was 1.2% (10/821): 1.5% (9/592) and 0.4% (1/229) in patients receiving infliximab and adalimumab, respectively. The median time to the development of active TB after initiation of anti-TNF therapy was three months (range: 2–36). Three patients had past histories of treatment for TB. Positive findings in a TB skin test (TST) and/or interferon gamma releasing assay (IGRA) were observed in three patients, and two of them received anti-TB prophylaxis. Two patients were negative by both TST and IGRA. The most common site of active TB was the lungs, and the active TB was cured in all patients.

Conclusions

Active TB can develop during anti-TNF therapy in IBD patients without LTBI, and even in those with histories of TB treatment or LTBI prophylaxis. Physicians should be aware of the potential for TB development during anti-TNF therapy, especially in countries with a high prevalence of TB.

Reactivation tuberculosis: role of surveillance

The incidence and death rates from tuberculosis (TB) have declined through concerted efforts in the diagnosis and treatment of active disease. Despite this, 9.6 million new cases and 1.1 million deaths in 2014 are unacceptably high. To decrease the rates of TB further, the huge number of persons with latent TB infection (LTBI) from whom new cases will arise has to be addressed with a sense of priority. Identifying the highest risk groups and providing effective treatment has been shown to decrease active TB. Further research to refine the predictors of reactivation and shorter effective treatments are urgently needed. Implementing intensified case finding, testing and treatment for LTBI will require continued investment in health care capacity at multiple levels.

Inflammatory Bowel Disease: An Overview of Immune Mechanisms and Biological Treatments

Inflammatory bowel diseases (IBD) are characterized by chronic inflammation of the intestinal tract associated with an imbalance of the intestinal microbiota. Crohn's disease (CD) and ulcerative colitis (UC) are the most widely known types of IBD and have been the focus of attention due to their increasing incidence. Recent studies have pointed out genes associated with IBD susceptibility that, together with environment factors, may contribute to the outcome of the disease. In ulcerative colitis, there are several therapies available, depending on the stage of the disease. Aminosalicylates, corticosteroids, and cyclosporine are used to treat mild, moderate, and severe disease, respectively. In Crohn's disease, drug choices are dependent on both location and behavior of the disease. Nowadays, advances in treatments for IBD have included biological therapies, based mainly on monoclonal antibodies or fusion proteins, such as anti-TNF drugs. Notwithstanding the high cost involved, these biological therapies show a high index of remission, enabling a significant reduction in cases of surgery and hospitalization. Furthermore, migration inhibitors and new cytokine blockers are also a promising alternative for treating patients with IBD. In this review, an analysis of literature data on biological treatments for IBD is approached, with the main focus on therapies based on emerging recombinant biomolecules.

Inflammatory Bowel Disease Cohort Studies in Korea: Present and Future

Inflammatory bowel disease (IBD) is defined as a chronic and relapsing inflammatory disorder of the intestine. Intestinal inflammation in IBD has been proposed to be attributable to the interplay between microbial, genetic, environmental, and immunological factors. The incidence and prevalence rates of IBD are rapidly increasing apparently in other parts of the world, with dramatic increases especially in East Asia. Generally, cohort studies are useful for estimating the incidence, prevalence, natural course, prognosis, and risk factors of diseases. In particular, cohort studies performed in Western countries have well described the prevalence, risk factors, and natural course of IBD and investigated its genetic pathophysiology. However, the outcomes of IBD cohort studies performed in Korea are not as persuasive as those of Western studies because of the relatively low prevalence of IBD and short follow-up periods of the cohorts in Korea. Despite this critical limitation, members of the Korean Association for the Study of Intestinal Diseases have demonstrated outstanding results. Some unique features of IBD patients in Korea are well demonstrated, such as thiopurine-induced leukopenia or risks of opportunistic tuberculosis infection in patients receiving tumor necrosis factor-α inhibitors. In this review, the present authors summarized the key points of the results of the cohort studies performed in Korea and explored future perspectives.

Diagnosis and Treatment of Latent Tuberculosis Infection due to Initiation of Anti-TNF Therapy

Patients with immune-mediated inflammatory diseases (IMIDs) are increasingly being treated with anti-tumor necrosis factor (TNF) agents and are at increased risk of developing tuberculosis (TB). Therefore, diagnosis and treatment of latent TB infection (LTBI) is recommended in these patients due to the initiation of anti-TNF therapy. Traditionally, LTBI has been diagnosed on the basis of clinical factors and a tuberculin skin test. Recently, interferon-gamma releasing assays (IGRAs) that can detect TB infection have become available. Considering the high-risk of developing TB in patients on anti-TNF therapy, the use of both a tuberculin skin test and an IGRA should be considered to detect and treat LTBI in patients with IMIDs. The traditional LTBI treatment regimen consisted of isoniazid monotherapy for 9 months. However, shorter regimens such as 4 months of rifampicin or 3 months of isoniazid/rifampicin are increasingly being used to improve treatment completion rates. In this review, the screening methods for diagnosing latent and active TB before anti-TNF therapy in patients with IMIDs will be briefly described, as well as the current LTBI treatment regimens, the recommendations for managing TB that develops during anti-TNF therapy, the necessity of regular monitoring to detect new TB infection, and the re-initiation of anti-TNF therapy in patients who develop TB.