Pediatric-Onset Mixed Connective Tissue Disease

Innovations in the care of childhood interstitial lung disease associated with connective tissue disease and immune-mediated disorders

Childhood interstitial lung disease (chILD) associated with connective tissue and immune mediated disorders is the second most common chILD diagnostic category. As knowledge of the molecular and genetic underpinnings of these rare disorders advances, the recognized clinical spectrum of associated pulmonary manifestations continues to expand. Pulmonary complications of these diseases, including ILD, confer increased risk for morbidity and mortality and contribute to increased complexity for providers tasked with managing the multiple organ systems that can be impacted in these systemic disorders. While pulmonologists play an important role in diagnosis and management of these conditions, thankfully they do not have to work alone. In collaboration with a multidisciplinary team of subspecialists, the pulmonary and other systemic manifestations of these conditions can be managed effectively together. The goal of this review is to familiarize the reader with the classic patterns of chILD and other pulmonary complications associated with primary immune-mediated disorders (monogenic inborn errors of immunity) and acquired systemic autoimmune and autoinflammatory diseases. In addition, this review will highlight current, emerging, and innovative therapeutic strategies and will underscore the important role of multidisciplinary management to improving outcomes for these patients.

Exploring clinical features and therapeutic outcomes in Indian children with mixed connective tissue disease: A multicenter study

INTRODUCTION

Mixed connective tissue disease (MCTD) is a rare entity in children. There is a paucity of studies on juvenile-onset MCTD (jMCTD) worldwide especially from Southeast Asia.

OBJECTIVES

To describe clinical and laboratory features of jMCTD diagnosed at pediatric rheumatology centers across India.

METHODS

A predesigned detailed case proforma in an excel format was prepared and was sent to all the Pediatric Rheumatology centers in India. Eleven centers provided the clinical and laboratory data of their jMCTD patients, which was then compiled and analyzed in detail.

RESULTS

Thirty-one jMCTD patients from 11 centers were included in the study. Our cohort had 27 females and four male patients over 12 months (August 2021 to July 2022). The median age at presentation was 12 years (range 5-18 years) and the median duration of symptoms was 24 months at diagnosis (range 2-96 months). The common features included arthritis (90%), malar rash (70.9%), and Raynaud's phenomenon (70.9%). At a mean follow-up of 43 months (range 1-168 months), 45% of them were in remission. There were two deaths reported, due to macrophage activation syndrome and sepsis respectively.

CONCLUSION

We present the largest multicenter experience on jMCTD from the Indian subcontinent. The study's findings serve as a crucial stepping stone toward unraveling the complexities of jMCTD and improving patient care and management strategies.

Childhood mixed connective tissue disease at disease onset: Evidence from a systematic review

OBJECTIVE

Childhood Mixed Connective Tissue Disease (cMCTD) is the rarest pediatric connective tissue disease that includes features of systemic lupus erythematosus, polymyositis/dermatomyositis, juvenile idiopathic arthritis, and systemic sclerosis, identified by Sharp in 1972 and whose diagnosis remains challenging. This systematic review aims to identify clinical features at the onset of cMCTD and manifestations not currently included into the available diagnostic criteria.

METHODS

A systematic literature review was performed in accordance with PRISMA guidelines 2020 using bibliographic databases: MEDLINE via PubMed and EMBASE.

ELIGIBILITY CRITERIA

patients diagnosed with MCTD with onset before 18 years.

STUDIES INCLUDED

registries, retrospective and prospective cohort studies, case series and reports with analysis of data on signs and symptoms of presentation.

RESULTS

39 articles were included (215 subjects, 82.5% female), mean age of 141 months (± 41 months DS, range 2.5-204). The most used criteria for the diagnosis of MCTD were the Kasukawa criteria (54.5%). The clinical manifestations described at onset were Raynaud's phenomenon (69.7%), arthritis (60.9%), muscular involvement (53.5%), dermatological signs (39.5%), swollen fingers or hands (29.3%), arthralgias (25.6%), fever (22.3%), lung involvement (14.4%), sclerodactily (13.5%), lymphadenopathy (10.7%) serositis (10.2%), esophageal involvement (6.9%), nervous system involvement (6.9%), xeroftalmia (3.7%), xerostomia (3.7%), hepatosplenomegaly (2.8%), cardiac involvement (2.8%), hepatitis (2.3%), parotiditis (2.3%), Hashimoto's thyroiditis (0.9%), ocular involvement (0.9%).

CONCLUSIONS

The data from this systematic review suggest great heterogeneity of the clinical presentation of cMCTD for which there are no validated diagnostic criteria that may suggest a new diagnostic approach to allow earlier or more accurate diagnosis in the future.

Longitudinal follow-up of mixed connective tissue disease and overlapping autoimmune diseases of childhood onset in the Afro-descendant population of the French West Indies

INTRODUCTION

Overlap autoimmune syndromes (OAS) and mixed connective tissue disease (MCTD) are rare in children. We performed a retrospective, longitudinal and descriptive study of Afro-Caribbean patients from the French West Indies followed for MCTD and OAS to describe their characteristics and outcomes during childhood.

METHODS

Retrospective study from January 2000 to 2023. Listings of patients were obtained from multiple sources: computerized hospital archives and national hospital-based surveillance system, registry of pediatricians and adult specialists in internal medicine and the national registry for rare diseases. MCTD was defined according to Kasukawa's criteria. OAS was defined as overlapping features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and dermatomyositis/autoimmune myositis (DM/AM).

RESULTS

Sixteen patients were included over a 23-year period (10 MCTD and 6 OAS). The incidence was 0.23 per 100,000 children-years. The mean age at diagnosis was 11.9 years old (2.4-17) with median follow up of 7.9 years (2.1-19.6). SLE phenotype was present in the highest, followed by SSc and DM/AM. Patients had an average of three flares during childhood (1-7). A quarter (25%) had symptomatic pulmonary arterial hypertension (PAH). Ninety-four percent received steroids during follow-up and 88% required a corticosteroid-sparing therapy. Three patients (19%) developed SLE after more than 10y of follow-up. There were no death and no chronic organ failure.

CONCLUSION

This is the largest pediatric cohort of MCTD and OAS in Afro-descendant patients treated in a country with a high standard of care. The clinical evolution did not differ between MCTD and OAS. The main complication was PAH, more frequent in our cohort.

Childhood rheumatic diseases: bites not only the joint, but also the heart

Cardiovascular involvement in juvenile rheumatic diseases is the primary manifestation in paediatric vasculitis and a major organ manifestation in paediatric connective tissue diseases. Though coronary vasculitis is the prototypical manifestation of Kawasaki disease, it can also be seen in patients with polyarteritis nodosa. Pericarditis is the most common manifestation seen in juvenile rheumatic diseases like systemic onset JIA, and lupus. Cardiac tamponade, valvular insufficiency, aortic root dilatation and arrhythmias are seen rarely. Cardiac involvement is often recognized late in children. The development of cardiac disease in juvenile systemic sclerosis is associated with a poor outcome. In long term, childhood onset of rheumatic diseases predisposes to diastolic dysfunction and premature atherosclerosis during adulthood. Key Points • Pericarditis is the most common cardiac manifestation in SLE and can lead to tamponade. • Conduction defects are common in juvenile mixed connective tissue disease and systemic sclerosis. • Pulmonary hypertension is a significant contributor to mortality in juvenile systemic sclerosis. • In Kawasaki disease, early treatment can reduce risk of coronary artery aneurysms.

Pediatric mixed connective tissue disease versus other overlap syndromes: a retrospective multicenter cohort study

Pediatric mixed connective tissue disease (MCTD) is a subgroup of overlap syndromes. We aimed to compare the characteristics and outcomes in children with MCTD and other overlap syndromes. All MCTD patients met either Kasukawa or Alarcon-Segovia and Villareal criteria. The patients with other overlap syndromes had the features of ≥ 2 autoimmune rheumatic diseases but did not meet MCTD diagnostic criteria. Thirty MCTD (F/M = 28/2) and thirty (F/M = 29/1) overlap patients were included (disease onset < 18 years). The most prominent phenotype at disease onset and the last visit was systemic lupus erythematosus (SLE) in the MCTD group; juvenile idiopathic arthritis and dermatomyositis/polymyositis, respectively, in the overlap group. At the last visit, systemic sclerosis (SSc) phenotype was more frequent among MCTD than overlap patients (60% vs. 33.3%; p = 0.038). The frequency of the predominant SLE phenotype had decreased (60% to 36.7%), while predominant SSc phenotype had increased (13.3% to 33.3%) during follow-up in MCTD patients. Weight loss (36.7% vs. 13.3%), digital ulcers (20% vs. 0), swollen hands (60% vs. 20%), Raynaud phenomenon (86.7% vs. 46.7%), hematologic involvement (70% vs. 26.7%), and anti-Sm positivity (29% vs. 3.3%) were more common, while Gottron papules (16.7% vs. 40%) were less frequent among MCTD than overlap patients (p < 0.05). A higher percentage of overlap patients achieved complete remission than MCTD patients (51.7% vs. 24.1%; p = 0.047). The disease phenotype and outcome differ between pediatric MCTD and other overlap syndromes where MCTD may be regarded as a more severe disease. Analyzing these patients could pave the way for early and effective treatment.

Capillaroscopy as a diagnostic tool in the diagnosis of mixed connective tissue disease (MCTD): a case report

BACKGROUND

The concept of mixed connective tissue disease (MCTD) as a unique connective tissue disease has endured for half a century. Disease onset can be in adulthood (MCTD) or of juvenile onset (jMCTD) and is characterized by overlapping features of systemic lupus erythematosus (SLE), polymyositis or dermatomyositis (PM/DM) and systemic sclerosis (SSc). No universally accepted classification criteria for MCTD exists, however agreed upon overlapping disease features include the presence of high titers of U1 small nuclear ribonucleoprotein particle antibodies (U1snRNP) in the peripheral blood, Raynaud's phenomenon, synovitis, myositis and swollen hands or fingers. Characteristic capillaroscopy findings are commonly seen in MCTD and jMCTD, which may represent a crucial and key clue for classification as well as prognosis in these patients.

CASE PRESENTATION

We present a young male patient, with symptom onset as early as age 13, who was diagnosed with MCTD at age 16 and found to have high titers of anti-U1snRNP antibodies, Raynaud's phenomenon, synovitis, and swollen hands and fingers. Most interestingly, his video capillaroscopy at diagnosis was abnormal and revealed an active SSc-like pattern. His presentation and course are described.

CONCLUSIONS

We conclude that based on existing data, and as highlighted by this case presentation, nailfold video capillaroscopy should be included as an early screening tool for the detection of microangiopathy in patients with the diagnosis MCTD and jMCTD. Additionally, given its prevalence in this population at disease diagnosis, we recommend consideration be given to nailfold video capillaroscopy as a potentially important classification criteria and prognostic tool for jMCTD and MCTD.

Pulmonary Manifestations of Rheumatic Diseases in Children

Children with rheumatic disease have rare pulmonary manifestations that may cause significant morbidity and mortality. These children are often clinically asymptomatic until disease has significantly progressed, so they should be screened for pulmonary involvement. There has been recent recognition of a high mortality-related lung disease in systemic-onset juvenile idiopathic arthritis; risk factors include onset of juvenile idiopathic arthritis less than 2 years of age, history of macrophage activation syndrome, presence of trisomy 21, and history of anaphylactic reaction to biologic therapy. Early recognition and treatment of lung disease in children with rheumatic diseases may improve outcomes.

Increased Endothelial Activation in Patients with Mixed Connective Tissue Disease

OBJECTIVE

Juvenile-onset mixed connective tissue disease (JMCTD) is a chronic inflammatory disease. We have previously demonstrated preclinical atherosclerosis in these patients, now exploring this further by assessing markers of endothelial dysfunction.

METHODS

Thirty-three patients with JMCTD and 33 age-and sex-matched controls were included. Soluble intercellular adhesion molecule-1 (sICAM-1), Il-6 and, von Willenbrand factor (vWF) were assayed from blood taken at the time of carotid ultrasound.

RESULTS

Our major findings were: (1) Levels of sICAM-1 (P < .001), IL-6 (P = .004), and vWF (P = .001) were higher, whereas (2) high density lipoprotein cholesterol (<.01) and apolipoprotein A1 (P < .01) were lower in the patient group compared to controls.

CONCLUSIONS

Patients with JMCTD had significantly increased levels of markers of endothelial dysfunction.

Effect on Cardiac Function of Longstanding Juvenile-onset Mixed Connective Tissue Disease: A Controlled Study

OBJECTIVE

To assess cardiac function in patients with juvenile mixed connective tissue disease (JMCTD) compared to matched controls, and to investigate possible associations between cardiac impairment and disease variables and cardiovascular risk factors.

METHODS

Fifty JMCTD patients (86% female) examined median 14.9 (6.6-23.0) years after disease onset were compared with 50 age- and sex-matched controls. Electrocardiogram and echocardiography [including e' as a marker for diastolic dysfunction and long-axis strain (LAS) and left ventricular (LV) ejection fraction (EF) as markers of systolic function] were performed. LV dysfunction (LVD) was defined as low EF, low LAS, or low e'. Right ventricular function was assessed with tricuspid annular plane systolic excursion (TAPSE). Cardiovascular risk factors and disease variables were assessed.

RESULTS

LVD was found in 16% of patients and 4% of controls (p = 0.035). EF and LAS were lower in patients compared to controls (6% lower, p < 0.001, and 4% lower, p = 0.044, respectively). TAPSE was 8% lower in patients versus controls (p = 0.008). No patients had signs of pulmonary hypertension. Patients had longer corrected QT time than controls (p = 0.012). LVD was associated with higher levels of apolipoprotein B, higher disease activity measured by physician's global assessment, longer prednisolone treatment, and more organ damage assessed with the Myositis Damage Index.

CONCLUSION

Patients with JMCTD had impaired left and right ventricular function compared to matched controls after median 15 years disease duration. High disease activity and longer treatment with prednisolone were factors associated with LVD.

Preclinical Carotid Atherosclerosis in Patients With Juvenile-Onset Mixed Connective Tissue Disease

BACKGROUND

This study investigated preclinical atherosclerosis in patients with juvenile mixed connective tissue disease (JMCTD), which is a chronic inflammatory disease with a varied phenotype. Mixed connective tissue disease (MCTD) has well known associations with other autoimmune diseases known to have increased risk of cardiovascular disease. However, the cardiovascular risk for patients with the juvenile form remains unclear.

MATERIALS AND METHODS

Forty-nine patients with JMCTD and 45 age-and sex-matched controls took part in this study. They underwent blood tests, clinical examination, and ultrasound measurement of the carotid arteries.

RESULTS

We found that patients had significantly higher average carotid intima-media thickness (IMT) as compared to controls (mean 0.57 ± 0.09 versus 0.53 ± 0.06, P = .03). IMT also increased with both increasing disease duration (years from diagnosis), and severity as assessed by the physicians global assessment score, after adjustment for age.

CONCLUSIONS

This is the first study to demonstrate increased preclinical atherosclerosis in juvenile MCTD. Our findings suggest that the atherosclerotic burden in this patient group, which was independent of traditional cardiovascular risk factors, might be secondary to the underlying connective tissue disease.

Clinical features and outcome of mixed connective tissue disease in developmental age - observational study from one center

Objectives

Mixed connective tissue disease is a rare systemic connective tissue disease of developmental age and it includes the features of arthritis, polymyositis/dermatomyositis, systemic lupus erythematosus and systemic sclerosis, with presence of anti-ribonucleoprotein antibodies (anti-RNP) in serum. Early diagnosis of the disease is difficult but essential in preventing development of systemic complications, which are often irreversible. International literature does not report many studies on large cohorts of children with this disease. The aim of this retrospective study was to define clinical characteristics and long-term results of treatment of the disease in 60 children with mixed connective tissue disease hospitalized in the period between 1978 and 2018. The diagnosis was established on the basis of Kasukawa’s criteria.

Material and methods

It was a group of 60 children (46 girls and 16 boys) aged 10.5 on average (4–16.5). When assessing general symptoms at the onset of the disease according to Kasukawa’s criteria, the highest number, over 80% of children, demonstrated symptoms suggesting SLE, about 40% suggesting DM and about 25% suggesting SSC. In the period of observation the number of children with clinical symptoms suggesting SSC increased. The most common clinical symptoms included Raynaud syndrome, arthritis and myositis and the most common irregularities in the test results included presence of anti-RNP antibodies and rheumatoid factor and hematological symptoms such as leukopenia/thrombocytopenia. Restrictive lung function impairment was demonstrated by 20% of children. Treatment most often included combined therapy (glucocorticosteroids + methotrexate/azathioprine).

Results

In 70% of the patients stable improvement was observed. Remission concerned 7% of the patients, frequent exacerbations were found in almost 20% of patients, and 2 children (3.5%) died.

Conclusions

The long term observations of patients in developementeal age with mixed connective tissue disease revealed that the majority of them had domination of SLE symptoms, only in 7% achieved remission and 70% remained in stable improvement. Serious infections with septic state were the cause of death in two cases.

Pulmonary Manifestations and Progression of Lung Disease in Juvenile-onset Mixed Connective Tissue Disease

OBJECTIVE

To assess the occurrence and extent of interstitial lung disease (ILD) in patients with juvenile mixed connective tissue disease (JMCTD), compare pulmonary function in patients and matched controls, study associations between ILD and disease-related variables, and examine progression of pulmonary manifestations over time.

METHODS

A cohort of 52 patients with JMCTD were examined in a cross-sectional study after a mean 16.2 (SD 10.3) years of disease duration with high-resolution computed tomography (HRCT) and pulmonary function tests (PFT) comprising spirometry, DLCO, and total lung capacity (TLC). Matched controls were examined with PFT. Previous HRCT and PFT were available in 37 and 38 patients (mean 8.8 and 10.3 yrs before study inclusion), respectively.

RESULTS

Compared to controls, patients with JMCTD had lower forced vital capacity (FVC), DLCO, and TLC (p < 0.01). The most frequent abnormal PFT was DLCO in 67% of patients versus 17% of controls (p < 0.001). Fourteen patients (27%) had ILD on HRCT. Most had ILD in < 10% of their lungs. ILD was associated with low values for FVC and TLC, but not with DLCO. HRCT findings did not progress significantly over time, but FVC declined (p < 0.01).

CONCLUSION

Compared to controls, patients with JMCTD had impaired pulmonary function. ILD was present in 27% of patients after a mean 16 years of disease duration, mostly as mild disease, and did not progress. ILD seems to be less common in juvenile-onset than in adult-onset MCTD, and ILD in JMCTD seems mostly mild and stable over time.

Systemic Lupus Erythematosus, Sjögren Syndrome, and Mixed Connective Tissue Disease in Children and Adolescents

Juvenile systemic lupus erythematosus (jSLE), mixed connective tissue disease (jMCTD), and Sjögren syndrome (jSS) are systemic autoimmune and inflammatory disorders with distinct patterns of organ involvement. All are characterized by autoantibody formation, with antinuclear (ANA) and anti-double-stranded DNA common in jSLE, ANA with high-titer ribonucleoprotein antibody in jMCTD, and Sjögren syndrome A and Sjögren syndrome B antibodies + ANA in jSS. Recognition, monitoring, and management for primary care providers are discussed, focusing on the role of primary physicians in recognizing and helping maintain optimal health in children with these potentially life-threatening diseases.

Pediatric Mixed Connective Tissue Disease

Pediatric-onset mixed connective tissue disease is among the rare disease entities in pediatric rheumatology and includes features of arthritis, polymyositis/dermatomyositis, systemic lupus erythematosus, and systemic sclerosis. Accurate recognition and diagnosis of the disease is paramount to prevent long-term morbidity. Advances in the genetic and immunologic understanding of the factors involved in the etiopathogenesis provide an opportunity for improvements in prognostication and targeted therapy. The development of a multinational cohort of patients with mixed connective tissue disease would be invaluable to provide more updated data regarding the clinical presentation, to develop a standardized treatment approach, disease activity and outcome tools, and to provide data on long-term outcomes and comorbidities.

Long-term outcome in juvenile-onset mixed connective tissue disease: a nationwide Norwegian study

OBJECTIVES

To describe the characteristics, outcome and predictive factors of juvenile mixed connective tissue disease (JMCTD) in a nationwide cohort of patients.

METHODS

We examined 55 patients with JMCTD after a mean disease duration of 16.2 years (SD 10.0). Patients were registered according to Kasukawa's criteria. Remission criteria were defined according to those for juvenile idiopathic arthritis, plus absence of cytopenia, myositis, progressive sclerodactyly, lung and oesophageal manifestations. Organ damage was assessed with the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology (ACR) Damage Index and the Juvenile Arthritis Damage Index (JADI). Medical records were reviewed for early predictors for outcome, which were assessed by multivariate logistic regression analyses.

RESULTS

Three patients developed systemic lupus erythematosus (SLE). Fifty-two patients had continuous JMCTD; the most common manifestations were: Raynaud (100%), arthritis (94%), puffy hands (77%) and pulmonary manifestations (58%). SLE-like, systemic sclerosis (SSc)-like and polymyositis (PM)-like findings were found in 98%, 77% and 48%, respectively. Over time, SLE-like and PM-like manifestations decreased, and SSc-like findings increased. At follow-up, 35 patients (67%) had active disease and 17 (33%) were in remission. In 34 patients (65%), SLICC or JADI≥1 assessments indicated organ damage. Active disease was associated with higher anti-ribonucleoprotein antibody titres at follow-up and positive rheumatoid factor (RF) at diagnosis and follow-up.

CONCLUSIONS

Most patients with JMCTD had active disease and organ damage after a mean follow-up of 16.2 years. Active disease was associated with higher anti-ribonucleoprotein antibody levels and positive RF. The presence of RF at diagnosis predicted persistent disease activity.

Rapid progression to pulmonary arterial hypertension crisis associated with mixed connective tissue disease in an 11-year-old girl

Mixed connective tissue disease (MCTD) is rare in pediatric rheumatic diseases. Pulmonary arterial hypertension (PAH) associated with MCTD usually progresses gradually and is difficult to note at the asymptomatic phase. We report a 11-year-old girl with MCTD complicated with rapidly progressive PAH. Although PAH was not detected by echocardiogram or chest CT scan at the initial examination, it became clear in 1 year and suddenly came to cardiac arrest during an invasive procedure. She was successfully treated with extracorporeal assist and both vasodilative and immunosuppressive medication. A combination of echocardiogram and plasma BNP levels could be a useful marker for the follow-up of such cases. PAH could develop early in the course of pediatric MCTD and needs attention to unexpected acute exacerbation, especially under emotional stress.

Diffuse and interstitial lung disease and childhood rheumatologic disorders

PURPOSE OF REVIEW

Advances in genetics and clinical diagnostics, along with recently described clinical entities and refined classification schemes, have improved our understanding of diffuse and interstitial lung diseases in children. This review presents recent updates in these disorders in the context of systemic inflammatory conditions.

RECENT FINDINGS

Classification of childhood diffuse lung disease (DLD) using adult paradigms is not useful. Distinct clinical-pathologic entities exist in children. Infants are more likely to present with genetic and developmental disorders, and older children with inflammatory and immune-mediated conditions. A combination of clinical evaluation, high-resolution computed tomography scanning, pulmonary function testing and serology, with bronchoscopy and surgical lung biopsy in selected cases, is most useful in the evaluation of DLD in the context of rheumatologic conditions. Common causes of DLD, such as infection, especially in the setting of immunodeficiency, must be ruled out. Optimal therapy for specific disorders will require careful analysis of data from national registries. Emerging use of biomarkers and high-throughput molecular analysis will yield novel insight into these disorders.

SUMMARY

In the setting of known or suspected rheumatologic disorders, diagnosis and management of DLD are challenging, and require close collaboration among rheumatologists, pulmonologists, and other specialists.

Pulmonary complications of childhood rheumatic disease

The array of paediatric pulmonary complications of the various rheumatologic disorders illustrates both the complexities and challenges of the underlying disorders and the continuing lack of detailed knowledge of the pathophysiology and optimal treatment paradigms in children. While the vertical transfer of information has made much progress from adult studies, such as with the diagnosis and management of pulmonary arterial hypertension, in many instances underlying disorders may differ between children and adults in important and fundamental respects. Recognition of pulmonary complications of rheumatic disorders in children is often more difficult and requires anticipation and a high index of suspicion. Further progress in understanding and treating the various paediatric disorders is hampered by the lack of paediatric-specific information. Crucial to further progress are the expansion of orphan childhood disease databases and research networks. In this way a comprehensive approach to determining basic natural history, risks and outcomes, and defining the next generation of therapies in a disease-specific and age-specific manner can be achieved.