Are infections in children with juvenile idiopathic arthritis more frequent than in healthy children? A prospective multicenter observational study

An update on the safety of biologic therapies for the treatment of polyarticular juvenile idiopathic arthritis

INTRODUCTION

An increasing number of patients with polyarticular course juvenile idiopathic arthritis are treated with biologics with great efficacy. Consequently, the importance regarding safety data in general as well as especially serious infections, incident autoimmune processes, or malignancies rises. In children, this is crucial concerning occurrences that manifest rarely and only after a prolonged latency period.

AREAS COVERED

This study aims to analyze safety under therapy with the five most commonly used biologicals for the treatment of juvenile idiopathic arthritis in Germany: abatacept, adalimumab, etanercept, golimumab, and tocilizumab, and a control cohort, who received methotrexate. For this, data from the Biologics in Pediatric Rheumatology (BiKeR) Registry were analyzed with a focus on potential adverse drug reactions like serious infections, autoimmune processes or malignancies.

EXPERT OPINION

Besides JIA category-specific differences, investigating side effects like severe infections and the development of additional autoimmune processes due to therapy is crucial. Future clinical randomized double-blinded studies are essential for direct drug comparisons, enabling optimal individualized therapy considering comorbidities and individual risks. Large patient data over a (life-)long period beyond childhood are particularly important, especially concerning the risk of malignancy after prolonged latency.

Unveiling the differences: infection disorders associated with tumor necrosis factor α inhibitors in pediatric patients-a pharmacovigilance study (2004-2023)

The increasing use of tumor necrosis factor inhibitors (TNFi) in pediatric patients has raised concerns about their potential impact on the immune system and related adverse events. Infection-related adverse events (AEs) caused by TNFi have already raised widespread concerns in real-world settings. This study aims to comprehensively analyze and summarize the infection-related AEs associated with TNFi in pediatric patients. A retrospective pharmacovigilance study was conducted to identify cases of TNFi-related infections reported to the FDA Adverse Event Reporting System (FAERS) database between Q1 2004 and Q1 2023. TNFi reports were carefully reviewed to exclude confounding factors like other AEs, concomitant medications, and prescription indications. Proportionality analysis was conducted by comparing TNFi reports to the entire FAERS database to identify infection-related AEs significantly associated with TNFi use. Infection-related AEs accounted for 8.36% of all TNFi-related adverse event reports in the FAERS database. A total of 8050 cases of TNFi-associated infections were identified in the pediatric population, with 2.57% of reports resulting in fatalities. Infliximab and golimumab showed a stronger association with infection-related AEs compared to other TNFi. Notably, only adalimumab shows a lower risk of viral infections, while it exhibits an increased risk of bacterial and mycobacterial infections, similar to other TNFi.

CONCLUSIONS

This study identified a significant association between TNFi use and infection-related AEs in pediatric patients, providing the foothold for further research. However, due to its retrospective nature, further investigations are warranted to confirm these findings and identify potential risk factors in a controlled, prospective study setting.

WHAT IS KNOWN

• There is sufficient evidence to demonstrate the infection risk associated with TNFi in adult patients. • Pediatric patients, whose immune systems are still developing, are more vulnerable to certain infections.

WHAT IS NEW

• There is a significant association between TNFi use and infection-related adverse events in pediatric patients, and different TNFi have distinct infection profiles.

Patients with juvenile idiopathic arthritis have decreased clonal diversity in the CD8+ T cell repertoire response to influenza vaccination

Recurrent exposures to a pathogenic antigen remodel the CD8+ T cell compartment and generate a functional memory repertoire that is polyclonal and complex. At the clonotype level, the response to the conserved influenza antigen, M158-66 has been well characterized in healthy individuals, but not in patients receiving immunosuppressive therapy or with aberrant immunity, such as those with juvenile idiopathic arthritis (JIA). Here we show that patients with JIA have a reduced number of M158-66 specific RS/RA clonotypes, indicating decreased clonal richness and, as a result, have lower repertoire diversity. By using a rank-frequency approach to analyze the distribution of the repertoire, we found several characteristics of the JIA T cell repertoire to be akin to repertoires seen in healthy adults, including an amplified RS/RA-specific antigen response, representing greater clonal unevenness. Unlike mature repertoires, however, there is more fluctuation in clonotype distribution, less clonotype stability, and more variable IFNy response of the M158-66 specific RS/RA clonotypes in JIA. This indicates that functional clonal expansion is altered in patients with JIA on immunosuppressive therapies. We propose that the response to the influenza M158-66 epitope described here is a general phenomenon for JIA patients receiving immunosuppressive therapy, and that the changes in clonal richness and unevenness indicate a retarded and uneven generation of a mature immune response.

Tumor-necrosis factor α-rich environment alters type-I interferon response to viral stimuli in patients with juvenile idiopathic arthritis by altering myeloid dendritic cell phenotype

The balance between the tumor-necrosis factor α (TNFα) and type-I interferon (T1IFN) pathways is crucial for proper immune function. Dysregulation of either pathway can contribute to autoimmune diseases development. Even though TNFα blockade has shown promising results in various autoimmune diseases, the effect on the balance between TNFα and T1IFN is elusive. We used targeted anti-TNFα therapies in juvenile idiopathic arthritis (JIA) as an experimental approach to study the cross-regulation between TNFα and type-I IFN. We found that TNFα-rich environment affected viral defense through the attenuation of T1IFN responses and affected the phenotype and distribution of myeloid dendritic cells, which are engaged in early viral infections. Anti-TNFα therapy normalized the observed deviations in JIA patients. We hypothesize that the inadequate immune response caused by a high TNFα environment could be projected to more frequent or lengthy viral infections and possibly play a role in the process of JIA disease development.

Position statement on infection screening, prophylaxis, and vaccination of pediatric patients with rheumatic diseases and immunosuppressive therapies, part 3: precautions in situations of surgery, fever, and opportunistic infections

The objective of this study is to provide practical recommendations on the management of pediatric patients with immune-mediated rheumatic diseases receiving immunosuppressive therapies. The recommendations specifically address the cases of surgery, fever, and opportunistic infections (varicella, herpes-zoster, tuberculosis, invasive fungal disease). A qualitative approach was applied. A narrative literature review was performed via Medline. Primary searches were conducted using MeSH terms and free text to identify publications on infections and vaccinations in pediatric patients with immune-mediated rheumatic diseases receiving immunosuppressive therapies. The results were presented and discussed in a nominal group meeting, comprising a committee of 12 pediatric rheumatologists from the Infection Prevention and Treatment Working Group of the Spanish Society of Pediatric Rheumatology. Several recommendations were generated. A consensus procedure was implemented via a Delphi process; this was extended to members of the Spanish Society of Pediatric Rheumatology and Spanish Society of Pediatric Infectious Disease of the Spanish Association of Pediatrics. Participants produced a score ranging from 0 (totally disagree) to 10 (totally agree). Agreement was defined as a vote ≥ 7 by at least 70% of participants. The literature review included more than 400 articles. Overall, 63 recommendations (19 on surgery, fever, and opportunistic infections) were generated and voted by 59 pediatric rheumatologists and other pediatric specialists. Agreement was reached for all 63 recommendations. The recommendations on special situations cover management in cases of surgery, fever, and opportunistic infections (varicella, herpes-zoster, tuberculosis, and invasive fungal disease).  Conclusions: Hereby, we provided consensus and updated of recommendations about the management of special situations such as surgery, fever, and opportunistic in children with immune-mediated rheumatic diseases receiving immunosuppressive therapies. Several of the recommendations depend largely on clinical judgement and specific balance between risk and benefit for each individual and situation. To assess this risk, the clinician should have knowledge of the drugs, the patient's previous situation as well as the current infectious disease, in addition to experience. What is Known: • Infectious diseases and related complications are a major cause of morbidity and mortality in patients with immune-mediated rheumatic diseases. • Information on how to manage the treatment in situations of fever, opportunistic infections, and surgery in children is limited, and guidelines for action are often extrapolated from adults. What is New: • In the absence of strong evidence, a literature review and a Delphi survey were conducted to establish a series of expert recommendations that could support the clinical practice, providing a practical and simple day-to-day approach to be used by pediatric rheumatologists.