Lung Involvement in Systemic Juvenile Idiopathic Arthritis: A Narrative Review

Clinical characteristics and prognosis of interstitial lung disease in systemic juvenile idiopathic arthritis: a two-center retrospective observational cohort study

BACKGROUND

Interstitial lung disease (ILD) is a serious complication in systemic juvenile idiopathic arthritis (SJIA). This study aimed to identify the clinical characteristics and prognosis of SJIA-ILD.

METHODS

A two-center retrospective cohort study was conducted on patients newly diagnosed with SJIA in China from October 2010 to December 2021. Clinical characteristics, laboratory parameters, outcomes, and relapse rates were compared between ILD and non-ILD groups.

RESULTS

A total of 176 children with SJIA were included, including 35 in ILD group and 141 in non-ILD group. The median age at onset of SJIA was 5.8 years (range 4.4-9.5) in patients with SJIA-ILD. It exhibited higher incidences of cervical spine (28.6%) and hip involvement (40.0%) in ILD group (P = 0.031 and P = 0.029, respectively). The incidence of macrophage activation syndrome (MAS) in ILD group reached up to 40%, significantly elevated than that in non-ILD group (P = 0.047). Children with ILD demonstrated a stronger inflammatory response and were more prone to developing lymphopenia (P = 0.009), requiring more combination therapy (P = 0.006) to control disease activity. 54.3% of patients received biologic therapies, with only three patient receiving biologics (one with IL-6 blockade, two with TNF inhibitor) prior to ILD onset and none receiving IL-1 blockade. The median follow-up duration was 6.0 years (range 3.9-9.5). The proportions of patients with SJIA-ILD achieving clinical inactive disease without glucocorticoids within 6 to 12 months of the treatment were significantly lower than control group (45.7% vs. 70.2%, P = 0.006). In ILD group, only 54.3% of patients achieved complete remission, and 17.1% were in a non-remission state, among whom two deaths from respiratory failure. There was no significant difference in disease relapse rates between the two groups (P > 0.05).

CONCLUSIONS

Patients with SJIA-ILD exhibited heightened inflammation, increased hip joint and cervical spine involvement, and were more susceptible to developing lymphopenia and MAS, suggesting a relatively poor prognosis. They required a prolonged time to control inflammation and more aggressive treatment strategies to achieve inactive status. The unsatisfactory rate of complete remission highlighted an urgent need for focused clinical strategies.

Initial Respiratory System Involvement in Juvenile Idiopathic Arthritis with Systemic Onset Is a Marker of Interstitial Lung Disease: The Results of Retrospective Cohort Study Analysis

Background: Pulmonary involvement in systemic juvenile idiopathic arthritis (SJIA) is a rare but dangerous complication. The main risk factors are already known, such as macrophage activation syndrome, a refractory course of systemic juvenile arthritis, infusion reaction to interleukin 1 and/or interleukin 6 blockers, trisomy 21, and eosinophilia. However, information about respiratory system involvement (RSI) at the onset of SJIA is scarce. Our study aimed to evaluate the specific features of children with SJIA with RSI and their outcomes. Methods: In a single-center retrospective cohort study, we compared the information from the medical records of 200 children with SJIA according to ILAR criteria or SJIA-like disease (probable/possible SJIA) with and without signs of RSI (dyspnea, shortness of breath, pleurisy, acute respiratory distress syndrome, and interstitial lung disease (ILD)) at the disease onset and evaluated their outcomes (remission, development of chronic ILD, clubbing, and pulmonary arterial hypertension). Results: A quarter (25%) of the SJIA patients had signs of the RSI at onset and they more often had rash; hepato- and splenomegaly; heart (pericarditis, myocarditis), central nervous system, and kidney involvement; hemorrhagic syndrome; macrophage activation syndrome (MAS, 44.4% vs. 9.0%, p = 0.0000001); and, rarely, arthritis with fewer active joints, compared to patients without RSI. Five patients (10% from the group having RSI at the onset of SJIA and 2.5% from the whole SJIA cohort) developed fibrosing ILD. All of them had a severe relapsed/chronic course of MAS; 80% of them had a tocilizumab infusion reaction and further switched to canakinumab. Unfortunately, one patient with Down's syndrome had gone. Conclusion: Patients with any signs of RSI at the onset of the SJIA are required to be closely monitored due to the high risk of the following fibrosing ILD development. They required prompt control of MAS, monitoring eosinophilia, and routine checks of night oxygen saturation for the prevention/early detection of chronic ILD.

Pediatric systemic juvenile idiopathic arthritis-related lung disease: Description of clinical cohort and review of management

CONTEXT

Since the early 2010s, there has been an increased awareness of interstitial lung disease in systemic juvenile idiopathic arthritis (sJIA-LD) in pediatric patients. Despite the increase in prevalence of sJIA-LD, little is known about this disease process and effective therapeutic management.

OBJECTIVES

To identify and characterize the disease process and management of interstitial lung disease related to systemic juvenile idiopathic arthritis.

STUDY DESIGN

In this single-center, retrospective case series of 9 patients, we analyze demographic, clinical, radiographic, and laboratory data to corroborate common clinical characteristics and describe an approach for diagnosis and monitoring of sJIA-LD.

DATA EXTRACTION

All data was extracted through electronic medical records and individually reviewed by two pediatric pulmonologists and two pediatric rheumatologists.

RESULTS

Our results were similar to other described cases of sJIA-LD as patients in our cohort were more likely to be younger, have a history of macrophage activation syndrome and prior use of biologic therapies. In contrast to prior studies, they did not present with peripheral lymphadenopathy and hepatosplenomegaly.

LIMITATIONS

The cohort size was small and data is reflective of one center's approach to management of a rare lung disease process.

CONCLUSION

Interstitial lung disease due to sJIA is rare and management can be difficult in these complex patients.More research is necessary to understand the increased incidence and treatment of sJIA-LD in pediatric population.

Janus Kinase Inhibitors and Interstitial Lung Disease Associated With Pediatric Rheumatic Diseases: An Unexplored Field

Rheumatic diseases are often complicated by lung disease, commonly presenting as interstitial lung disease (ILD), with potentially detrimental consequences for patient survival. Although less frequent in pediatric patients, pulmonary involvement may be observed in almost all childhood-onset rheumatic conditions. The development of biological disease-modifying anti-rheumatic drugs has significantly improved clinical outcomes. However, disease remission is not always complete or long-lasting, and treatment may need to be discontinued due to adverse effects. A novel class of drugs, namely Janus kinase inhibitors (JAKis), has been proposed to provide a significant survival benefit for patients with rheumatic diseases. Despite the ample literature on the efficacy and safety of JAKis in rheumatic disease, only a few studies have investigated the effectiveness of these drugs in patients with pulmonary involvement, and only two case reports have presented results in pediatric patients. We provide an overview of the rationale for using JAKis in ILDs associated with rheumatic disease and summarize the main studies evaluating their efficacy in both adult and pediatric patients. The present review highlights the need for controlled long-term studies to assess the efficacy and safety of JAKis in pediatric rheumatic disease complicated by lung disease.

Systemic juvenile idiopathic arthritis: The Great Ormond Street Hospital experience (2005-2021)

Systemic juvenile idiopathic arthritis (sJIA) is a complex, systemic inflammatory disorder driven by both innate and adaptive immunity. Improved understanding of sJIA pathophysiology has led to recent therapeutic advances including a growing evidence base for the earlier use of IL-1 or IL-6 blockade as first-line treatment. We conducted a retrospective case notes review of patients diagnosed with sJIA over a 16-year period (October 2005-October 2021) at Great Ormond Street Hospital for Children. We describe the clinical presentation, therapeutic interventions, complications, and remission rates at different timepoints over the disease course. We examined our data, which spanned a period of changing therapeutic landscape, to try and identify potential therapeutic signals in patients who received biologic treatment early in the disease course compared to those who did not. A total of 76-children (female n = 40, 53%) were diagnosed with sJIA, median age 4.5 years (range 0.6-14.1); 36% (27/76) presented with suspected or confirmed macrophage activation syndrome. A biologic disease-modifying anti-rheumatic drug (bDMARD) alone was commenced as first-line treatment in 28% (n = 21/76) of the cohort; however, at last review, 84% (n = 64/76) had received treatment with a bDMARD. Clinically inactive disease (CID) was achieved by 88% (n = 67/76) of the cohort at last review; however, only 32% (24/76) achieved treatment-free CID. At 1-year follow-up, CID was achieved in a significantly greater proportion of children who received treatment with a bDMARD within 3 months of diagnosis compared to those who did not (90% vs. 53%, p = 0.002). Based on an ever-increasing evidence base for the earlier use of bDMARD in sJIA and our experience of the largest UK single-centre case series described to date, we now propose a new therapeutic pathway for children diagnosed with sJIA in the UK based on early use of bDMARDs. Reappraisal of the current National Health Service commissioning pathway for sJIA is now urgently required.

Systemic Juvenile Idiopathic Arthritis and Secondary Macrophage Activation Syndrome in Latvia from 2009 to 2020: A Nationwide Retrospective Study

Background and Objectives: Systemic juvenile idiopathic arthritis (sJIA) is a distinctive JIA subtype with mostly nonspecific systemic clinical features, which can be a diagnostic challenge. This study aimed to analyze our experience with sJIA in Latvia for twelve years: assessing clinical and epidemiological characteristics, the efficacy of therapy, and disease outcomes, including the development of macrophage activation syndrome (MAS). Materials and methods: This is a descriptive study in which we conducted a retrospective case review of all patients with sJIA diagnosis admitted to the only pediatric tertiary centre in Latvia during the period 2009-2020. Results: sJIA was diagnosed in 35 patients with a mean annual incidence rate of 0.85 patients per 100,000 children. Major clinical signs at the first visit were: fever, rash, arthritis, and lymphadenopathy. Almost half of the patients, 48.5%, had a monocyclic disease course, and only 20% of patients had persistent disease. MAS developed in 28.6% of patients. Biological therapy was administered to 48.6% of patients, mostly by tocilizumab, which induced remission in 75% after one year, and in 81.2% after two years without any serious therapy-related complications. In our study, none of the patients had interstitial lung disease, drug reaction with eosinophilia and systemic symptoms (DRESS)-like syndrome, or fatal disease. Conclusions: The incidence and clinical characteristics of sJIA correlate with the literature findings, although MAS was more common than described in other studies. There is a tendency for the persistent disease to decrease with the use of biological therapy. Tocilizumab is an efficient choice of treatment with a good safety profile.