Preventing tuberculosis in children receiving anti-TNF treatment

Tuberculosis and TNF-α inhibitors in children: how to manage a fine balance

Since the introduction of biologic response modifiers (BRMs) in the management of children affected by the immune-mediated inflammatory disease, these patients substantially improved their quality of life. BRMs are generally well tolerated and effective in most children and adolescents refractory to conventional immunosuppressive therapy. On the other hand, patients receiving BRMs, especially TNF-α inhibitors, display an increased risk of primary infections or reactivations, i.e. due to Mycobacterium tuberculosis. M. tuberculosis can cause severe disease with consequent short- and long-term morbidity in children on anti-TNF-α treatment. The present paper analyses the increased risk of reactivation of latent tuberculosis infection (LTBI) or de novo TB infection in children treated with TNF-α inhibitors, with the purpose to provide recommendations for screening strategies and safety monitoring of paediatric patients. Special attention is also given to the currently available TB screening tools (IGRAs and TST) and their utility in the diagnosis of LTBI before starting the biologic therapy and during the treatment. Finally, the paper analyses the suggested TB-preventing therapies to adopt in these children and the correct timing to overlap anti-TB and anti-TNF-a treatment.

The necessity, efficacy and safety of biologics in juvenile idiopathic arthritis

OBJECTIVE:

Juvenile idiopathic arthritis (JIA) is the most common cause of chronic arthritis in children. Biologics have changed the faith of children with rheumatic diseases. The main objective of this study was to demonstrate the rate of usage, efficacy and safety of biologics in JIA subtypes.

METHODS:

This retrospective observational cohort study was conducted between May 2010 and September 2017. All children with the diagnosis of JIA and children under a biological agent treatment were recorded into the local registry system. Age, gender, JIA subtype, medications used, the clinical status of the patient, tuberculosis screening results, and side effects observed under biologics were retrieved from the registry.

RESULTS:

There were 405 patients with the diagnosis of JIA in the cohort. Biologics were used in 123 (30.3%) JIA patients. Subtype frequencies of JIA patients were as follows: persistent oligoarticular JIA (33.6%), enthesitis-related arthritis (29.2%), systemic JIA (13%), rheumatoid factor (RF)-negative polyarticular JIA (13%), extended oligoarticular JIA (4.2%), RF-positive polyarticular JIA (3.4%), psoriatic arthritis (1.8%) and unclassified arthritis (1.8%). The rate of biologic use was high in extended oligoarticular JIA (64.7% of the cases), RF-positive polyarticular JIA (57.1%), psoriatic arthritis (57.1%), RF-negative polyarticular JIA (41.5%), and in systemic JIA (39.6%). Enthesitis-related arthritis (27.1%), persistent oligoarticular JIA (17.6%) and unclassified arthritis (16.6%) patients were the cases that needed a biologic agent in the last order. At the last control, 78.9% of the cases were in remission, while 21.1% of them were active despite biologic treatment. Isoniazid prophylaxis was used in 30.8% of the patients. None of the patients developed active tuberculosis infection under prophylaxis. Adverse events were observed in 18.6% of patients under biologics as recurrent uncomplicated upper respiratory tract infections being the most common.

CONCLUSION:

Biologics are safe and effective treatment options in children with JIA. Most of the JIA patients with polyarticular involvement require biologics earlier in the disease course. The risk of tuberculosis infection seems not to be increased after appropriate screening and prophylaxis.

Treatment of latent tuberculosis in patients with juvenile rheumatic diseases: a systematic review

INTRODUCTION

Children and adolescents with rheumatic diseases receiving TNF blockers are at risk for the activation of latent Mycobacterium tuberculosis infection (LTBI). Although LTBI treatment is indicated in this group, there are different therapeutic regimens in the literature, without a definite consensus.

OBJECTIVES

To review in the literature therapeutic schemes used and indicated for the treatment of LTBI in these patients.

METHODS

Systematic review of the literature, using health databases, selecting studies that addressed the treatment of LTBI in patients with juvenile rheumatic diseases using TNF blockers, from 1990 to 2015. All study designs were considered.

RESULTS

A total of 162 studies were identified through the electronic databases and one was found through a manual search by the author, totaling 163 articles. We excluded studies that did not meet the mentioned inclusion criteria, and included a retrospective cohort study and two prospective cohort studies. The three studies addressed treatment with isoniazid (INH) for 9 months and one of them also addressed INH treatment associated with rifampicin for 3 months.

CONCLUSIONS

Only one case of LTBI activation was observed; there was good treatment adherence and absence of complications during follow-up. More studies are necessary to evaluate the response to the other available therapeutic regimens, with better tolerability assessment and a larger sample. However, the results showed that INH therapy for 9 months and INH therapy plus rifampicin for 3 months had a low rate of LTBI activation and complications.

Latent tuberculosis infection screening in juvenile idiopathic arthritis patients preceding anti-TNF therapy in a tuberculosis high-risk country

OBJECTIVES

To evaluate, in an endemic country, the long-term efficacy of latent tuberculosis infection (LTBI) screening and primary prophylaxis in patients with JIA receiving TNF blockers.

METHODS

This was a retrospective cohort that included JIA patients eligible to anti-TNF therapy. Patients were screened for LTBI prior to anti-TNF using tuberculin skin test (TST), chest X-ray and history of exposure to TB. Subjects were regularly followed at 2-month intervals.

RESULTS

Sixty-nine JIA patients with current age of 17.4±5.8 years, mean disease duration of 5.0±4.9 years were included. Forty-seven patients received a single anti-TNF, while 22 patients switched to another anti-TNF once or twice: 57 were treated with etanercepte, 33 patients with adalimumab and 3 infliximab. LTBI screening was positive in three patients: one had TST-positive and history of TB exposure and two had solely TST-positive. No active TB was diagnosed during the study period (median of follow-up was 3.8 years).

CONCLUSION

Long-term evaluation revealed that LTBI screening and primary prophylaxis before anti-TNF treatment was effective in a high-risk country and TST was the most sensitive parameter to identify these patients.

Infectious Complications With the Use of Biologic Response Modifiers in Infants and Children

Biologic response modifiers (BRMs) are substances that interact with and modify the host immune system. BRMs that dampen the immune system are used to treat conditions such as juvenile idiopathic arthritis, psoriatic arthritis, or inflammatory bowel disease and often in combination with other immunosuppressive agents, such as methotrexate and corticosteroids. Cytokines that are targeted include tumor necrosis factor α; interleukins (ILs) 6, 12, and 23; and the receptors for IL-1α (IL-1A) and IL-1β (IL-1B) as well as other molecules. Although the risk varies with the class of BRM, patients receiving immune-dampening BRMs generally are at increased risk of infection or reactivation with mycobacterial infections (Mycobacterium tuberculosis and nontuberculous mycobacteria), some viral (herpes simplex virus, varicella-zoster virus, Epstein-Barr virus, hepatitis B) and fungal (histoplasmosis, coccidioidomycosis) infections, as well as other opportunistic infections. The use of BRMs warrants careful determination of infectious risk on the basis of history (including exposure, residence, and travel and immunization history) and selected baseline screening test results. Routine immunizations should be given at least 2 weeks (inactivated or subunit vaccines) or 4 weeks (live vaccines) before initiation of BRMs whenever feasible, and inactivated influenza vaccine should be given annually. Inactivated and subunit vaccines should be given when needed while taking BRMs, but live vaccines should be avoided unless under special circumstances in consultation with an infectious diseases specialist. If the patient develops a febrile or serious respiratory illness during BRM therapy, consideration should be given to stopping the BRM while actively searching for and treating possible infectious causes.

Tuberculosis in pediatric patients treated with anti-TNFα drugs: a cohort study

BACKGROUND

Adult patients receiving anti-TNFα drugs are at increased risk of tuberculosis (TB), but studies in pediatric populations are limited, and the best strategy for latent tuberculosis infection (LTBI) screening in this population remains controversial. We describe the prevalence of LTBI prior to anti-TNFα therapy and the long-term follow-up after biological treatment initiation in a cohort of children and adolescents.

METHODS

Cohort observational study in children and adolescents receiving anti-TNFα agents in a tertiary-care pediatric hospital. LTBI was ruled out prior to the implementation of anti-TNFα drugs by tuberculin skin test (TST), and, from March 2012 on, QuantiFERON Gold-In Tube test (QTF-G). During anti-TNFα treatment, patients were evaluated every 6 months for TB with history and physical examination. TST/QTF-G were not repeated unless signs or symptoms consistent with TB arose or there was proven TB contact.

RESULTS

The final cohort consisted of 221 patients (56.1% female; 261 treatments), of whom 51.7%/30.0%/17.3% were treated with etanercept/adalimumab/infliximab, respectively, for a variety of rheumatic diseases (75.6%), inflammatory bowel disease (20.8%), and inflammatory eye diseases (3.6%). The median (IQR) age at diagnosis of the primary condition was 6.8 years (2.7-11.0) and the duration of the disease before implementing the anti-TNFα agent was 1.8 years (0.6-4.2). LTBI was diagnosed in 3 adolescent girls (prevalence rate: 1.4%; 95% CI: 0.4-4.2) affected with juvenile idiopathic arthritis: TST tested positive in only 1, while QTF-G was positive in all cases (including 2 patients already on etanercept). They all received antiTB chemoprophylaxis and were later (re)treated with etanercept for 24-29 months, without incidences. No incident cases of TB disease were observed during the follow-up period under anti-TNFα treatment of 641 patients-year, with a median (IQR) time per patient of 2.3 years (1.4-4.3).

CONCLUSIONS

In our study, the prevalence of LTBI (1.4%) was similar to that reported in population screening studies in Spain; no incident cases of TB disease were observed. In low-burden TB settings, initial screening for TB in children prior to anti-TNFα treatment should include both TST and an IGRA test, but systematic repetition of LTBI immunodiagnostic tests seems unnecessary in the absence of symptoms or known TB contact.

Assessment of tuberculosis infection during treatment with biologic agents in a BCG-vaccinated pediatric population

Biologic therapies, such as tumor necrosis factor-alpha (TNF-α) blockers, are commonly used to treat rheumatological diseases in childhood. Screening patients for tuberculosis (TB) is highly recommended before starting therapy with TNF-α blockers. Despite appropriate screening, TB still remains a problem in patients receiving anti-TNF therapy in countries where TB is not endemic. TB in anti-TNF-treated patients is often diagnosed late due to altered presentation, and this delay results in high morbidity and mortality with a high proportion of extrapulmonary and disseminated disease. The aim of this study is to show the course of TB disease in children who are on biologic therapy, in an era where many of the children are BCG-vaccinated and TB is intermediately endemic. We recruited 71 patients with several types of inflammatory diseases. Six of them had a positive test result during TB screening and began taking isoniazid (INH) prophylactically. During the 3 years of follow-up, none of these patients developed TB disease. Biologic agents can be safely used in a BCG-vaccinated pediatric population, as long as patients are closely monitored to ensure that any cases of TB will be detected early.

Role of adalimumab in the management of children and adolescents with juvenile idiopathic arthritis and other rheumatic conditions

Treatment of children and adolescents with juvenile idiopathic arthritis and other pediatric rheumatic diseases has evolved. Where once there was only a limited arsenal of medications, with significant side effects and inadequate efficacy, today, with an increased understanding of the pathogenesis of these diseases, there is a wider variety of more targeted and effective treatments. TNF-α is a cytokine involved in a number of inflammatory pathways in pediatric rheumatic diseases. The emergence of biologic modifiers that target TNF-α has been pivotal in providing the ability to deliver early and aggressive treatment. Adalimumab, a recombinant monoclonal antibody to TNF-α, is an important therapeutic option, which affords children and adolescents with chronic illnesses an improved quality of life.

Is it safe to use anti-TNF-α agents for tuberculosis in children suffering with chronic rheumatic disease?

To determine the incidence of latent tuberculosis infection and evaluate the follow-up protocol of the patients diagnosed with juvenile idiopathic arthritis (JIA) and other chronic rheumatologic diseases treated with anti-TNF-α treatment (etanercept, infliximab, adalimumab) in Turkey, 144 patients were evaluated retrospectively for the development of tuberculosis. Patients were evaluated every 6 months for tuberculosis using history, physical examination, tuberculin skin test (TST), chest radiographs, and, when required, examination of sputum/early morning gastric aspirates for acid-fast bacilli and chest tomography. A tuberculin skin test over 10 mm induration was interpreted as positive. Patients were diagnosed with JIA (n = 132), enthesitis-related arthritis (ERA; n = 14), juvenile psoriatic arthritis (JPsA; n = 4), chronic idiopathic uveitis (n = 4), and chronic arthritis related to FMF (n = 8). Mean age was 12.25 ± 3.96 years (4.08-19.41 years), mean duration of illness was 5.86 ± 3.77 years (0.66-15 years), and the mean duration of anti-TNF-α treatment was 2.41 ± 1.47 years (0.6-7 years). Anti-TNF-α agents prescribed were etanercept (n = 133), infliximab (n = 30), and adalimumab (n = 6). When unresponsive to one anti-TNF-α therapy, patients were switched to another. There was no history of contact with individuals having tuberculosis. During follow-up, seven patients (4.8%) with positive TST were given INH prophylaxis. One oligoarticular JIA patient (0.69%) diagnosed with secondary uveitis who had been followed for 5 years and had been using infliximab for 2 years, developed a positive Quantiferon-TB test while on INH prophylaxis. He was started on an anti-tuberculosis drug regimen. In conclusion, anti-TNF-α treatment in children with chronic inflammatory disease is safe. Follow-up every 6 months of children on anti-TNF-α treatment with respect to tuberculosis by the pediatric infectious disease department is important to prevent possible complications.

[Biological therapy in pediatrics]

In the late 1980s, the murine monoclonal antibody muromonab was used in children undergoing organ transplantation. Since then, dozens of new molecules have been developed to modulate the immune response, block growth factors, or prevent infections on the basis of the antigen-antibody-specific response. In pediatrics, most biological therapies are used off-label, although they are effective and well tolerated and are used as first-line therapy in some severe genetic diseases. Biologicals allow specific targeting and can be engineered against any antigen. The safety of these treatments varies depending on the molecule and precise knowledge of side effects is essential for clinicians. The development of these promising agents requires clinical trials in children to validate their effectiveness and safety in the medium and long term.