Distinguishing Blau Syndrome from Systemic Sarcoidosis

The Etiologic Landscape of Lymphoproliferation in Childhood: Proposal for a Diagnostic Approach Exploring from Infections to Inborn Errors of Immunity and Metabolic Diseases

Lymphoproliferation is defined by lymphadenopathy, splenomegaly, hepatomegaly, or lymphocytic organ and tissue infiltration. The most common etiologies of lymphoproliferation are represented by infectious diseases and lymphoid malignancies. However, it is increasingly recognized that lymphoproliferative features can be the presenting sign of rare conditions, including inborn errors of immunity (IEI) and inborn errors of metabolism (IEM). Among IEI, lymphoproliferation is frequently observed in autoimmune lymphoproliferative syndrome (ALPS) and related disorders, common variable immunodeficiency (CVID), activated phosphoinositide 3-kinase δ syndrome, and Epstein-Barr virus (EBV)-related disorders. Gaucher disease and Niemann-Pick disease are the most common IEMs that can present with isolated lymphoproliferative features. Notably, other rare conditions, such as sarcoidosis, Castleman disease, systemic autoimmune diseases, and autoinflammatory disorders, should be considered in the differential diagnosis of patients with persistent lymphoproliferation when infectious and malignant diseases have been reasonably ruled out. The clinical features of lymphoproliferative diseases, as well as the associated clinical findings and data deriving from imaging and first-level laboratory investigations, could significantly help in providing the correct diagnostic suspicion for the underlying etiology. This paper reviews the most relevant diseases associated with lymphoproliferation, including infectious diseases, hematological malignancies, IEI, and IEM. Moreover, some practical indications to orient the initial diagnostic process are provided, and two diagnostic algorithms are proposed for the first-level assessment and the approach to persistent lymphoproliferation, respectively.

Insights into the diagnosis and management of sarcoid uveitis: A review

Sarcoidosis is a leading cause of non-infectious uveitis that commonly affects middle-aged individuals and has a female preponderance. The disease demonstrates age, sex and ethnic differences in clinical manifestations. A diagnosis of sarcoidosis is made based on a compatible clinical presentation, supporting investigations and histologic evidence of non-caseating granulomas, although biopsy is not always possible. Multimodal imaging with widefield fundus photography, optical coherence tomography and angiography can help in the diagnosis of sarcoid uveitis and in the monitoring of treatment response. Corticosteroid remains the mainstay of treatment; chronic inflammation requires steroid-sparing immunosuppression. Features on multimodal imaging such as vascular leakage may provide prognostic indicators of outcome. Female gender, prolonged and severe uveitis, and posterior involving uveitis are associated with poorer visual outcomes.

A clinical overview of paediatric sarcoidosis: Multicentre experience from Turkey

OBJECTIVES

We aimed to outline the demographic data, clinical spectrum, and treatment approach of sarcoidosis in a large group of patients and sought to figure out the variations of early-onset (EOS) and late-onset paediatric sarcoidosis (LOS).

METHODS

The study followed a retrospective-descriptive design, with the analysis of medical records of cases diagnosed as paediatric sarcoidosis.

RESULTS

Fifty-two patients were included in the study. The median age at disease onset and follow-up duration were 83 (28.2-119) and 24 (6-48) months, respectively. Ten (19.2%) cases had EOS (before 5th birthday) and 42 (80.7%) cases had LOS. The most common clinical findings at the time of the disease onset were ocular symptoms (40.4%) followed by joint manifestation (25%), dermatological symptoms (13.5%), and features related to multi-organ involvement (11.5%). Anterior uveitis was the most common (55%) one among ocular manifestations. Patients with EOS displayed joint, eye, and dermatological findings more commonly than patients with LOS. The recurrence rate of disease in patients with EOS (5.7%) and LOS (21.1%) were not statistically different (P = .7).

CONCLUSIONS

Patients with EOS and LOS may present with variable clinical features and studies addressing paediatric sarcoidosis cases in collaboration between disciplines will enhance the awareness of this rare disease among physicians and assist early diagnosis with lesser complications.

Advance in pathogenesis of sarcoidosis: Triggers and progression

Sarcoidosis, a multisystemic immune disease, significantly impacts patients' quality of life. The complexity and diversity of its pathogenesis, coupled with limited comprehensive research, had hampered both diagnosis and treatment, resulting in an unsatisfactory prognosis for many patients. In recent years, the research had made surprising progress in the triggers of sarcoidosis (genetic inheritance, infection and environmental factors) and the abnormal regulations on immunity during the formation of granuloma. This review consolidated the latest findings on sarcoidosis research, providing a systematic exploration of advanced studies on triggers, immune-related regulatory mechanisms, and clinical applications. By synthesizing previous discoveries, we aimed to offer valuable insights for future research directions and the development of clinical diagnosis and treatment strategies.

Cutaneous Sarcoidosis

Sarcoidosis is a multisystem disease that most commonly affects the lungs, lymphatic system, eyes, and skin but any organ may be involved. Cutaneous sarcoidosis most commonly presents as pink-red to red-brown papules and plaques that commonly affect the head and neck. With the skin being readily accessible for evaluation and biopsy, when sarcoidosis is suspected, dermatologic evaluation may be helpful for establishing a definitive diagnosis. Treatment strategy depends on the severity and distribution of skin lesions and should incorporate patient preference and treatment considerations for other organs that may be involved.

Phenotype of Takayasu-like vasculitis and cardiopathy in patients with Blau syndrome

OBJECTIVES

We aimed to determine the prevalence of cardiovascular involvement in our Blau syndrome (BS) cohort and provide detailed analysis of their cardiovascular manifestations and outcome. We also tried to find out the risk factors for developing cardiovascular involvement.

METHODS

Clinical manifestations, laboratory findings, and treatments were reviewed. Clinical features were compared between children with cardiovascular involvement and those without angiocardiopathy.

RESULTS

A total of 38 BS children were eligible for final analysis. Among them, 13 (34.2%) developed Takayasu-like vasculitis and/or cardiopathy. Compared with those without angiocardiopathy, recurrent fever was more frequent in BS patients with cardiovascular involvement (p < 0.001). What is more, tumor necrosis factor alpha antagonists (anti-TNF) were more urgently needed in children with cardiovascular involvement (p = 0.015). BS patients with cardiovascular involvement include 4 with Takayasu-like vasculitis and 9 with cardiopathy. The onset of cardiovascular manifestations ranged from 0.75 to 18.5 years of age, with most cases occurring before school period. Symptoms were elusive and lacked specificity, such as dizziness, short of breath, and edema. Some patients were even identified because of the unexpected hypertension during follow-up. Cardiopathy and vasculitis occurred in patients with different genotypes. Imaging changes were discovered before the presentation of the typical triad in 3/4 patients with Takayasu-like vasculitis. Three children developed left ventricular dysfunction with decreased left ventricular ejection fraction. Combination of glucocorticoids and methotrexate with anti-TNF agents is a common treatment option for these BS patients. In the cohort, BS-related cardiovascular involvement was controlled well, with cardiac structural and functional abnormalities completely recovered and slower progression of vasculitis lesions.

CONCLUSION

Cardiovascular manifestations is not rare in BS patients. Because of its insidious onset, a systematic and comprehensive assessment of cardiovascular involvement should be performed in newly diagnosed patients with BS. Aggressive initiation of anti-TNF agents may be beneficial to improve the prognosis. Key Points • About 34.2% patients with Blau syndrome developed Takayasu-like vasculitis and/or cardiopathy. • Compared with those without angiocardiopathy, recurrent fever and application of anti-TNF agents were more frequent in BS patients with cardiovascular involvement (p < 0.001, p = 0.015) • Regular assessment of cardiovascular involvement is extremely necessary because of its insidious onset.

Molecular Foundations of Inflammatory Diseases: Insights into Inflammation and Inflammasomes

Inflammatory diseases are a global health problem affecting millions of people with a wide range of conditions. These diseases, including inflammatory bowel disease (IBD), rheumatoid arthritis (RA), osteoarthritis (OA), gout, and diabetes, impose a significant burden on patients and healthcare systems. A complicated interaction between genetic variables, environmental stimuli, and dysregulated immune responses shows the complex biological foundation of various diseases. This review focuses on the molecular mechanisms underlying inflammatory diseases, including the function of inflammasomes and inflammation. We investigate the impact of environmental and genetic factors on the progression of inflammatory diseases, explore the connection between inflammation and inflammasome activation, and examine the incidence of various inflammatory diseases in relation to inflammasomes.

Management of Blau syndrome: review and proposal of a treatment algorithm

Blau syndrome is a rare genetic granulomatosis affecting children. It could be responsible for vision-threatening complications and articular deformation. Due to the rarity of this disease, there are no standardized guidelines for its management. This work aimed to provide an updated overview of the different therapeutic options for Blau syndrome. We conducted research in the PubMed database for the different treatments used in Blau syndrome patients, and we proposed a therapeutic algorithm for disease management. High doses of corticosteroids are considered as a bridging therapy in Blau syndrome. Methotrexate should be initiated if the patient has articular or ocular involvement. An anti-tumor necrosis factor α should be added for patients with uveitis or residual arthritis. If the patient remains symptomatic, a switch to another anti-tumor necrosis factor α is the best option. In non-responders to the first- and second-line biotherapies, a switch to an anti-interleukin 1, an anti-interleukin 6, or tofacitinib is necessary.

CONCLUSION

This article suggested an algorithm for the treatment of Blau syndrome. Other studies are necessary to confirm the efficacy of these treatments.

WHAT IS KNOWN

• Blau syndrome is a rare but severe granulomatosis that could be responsible for vision-threatening complications and articular deformation. • Blau syndrome seems to be refractory to treatments.

WHAT IS NEW

• High doses of corticosteroids are usually insufficient and should be considered only as a bridging therapy. • Blau syndrome could be considered as a poor factor for uveitis, thus, an anti-tumor necrosis factor α should be initiated for patients with uveitis or with residual arthritis.

Imaging Features of Pediatric Sarcoidosis

Sarcoidosis is a granulomatous inflammatory disease of uncertain cause. It occurs most commonly in young and middle-aged adults and less frequently in children; therefore, few data on pediatric sarcoidosis exist in the literature. The diagnosis and management of sarcoidosis remain challenging because of diverse and often nonspecific clinical and imaging findings. In addition, the clinical picture varies widely by age. Prepubertal and adolescent patients often present with adult-like pulmonary disease; however, early-onset sarcoidosis is typically characterized by the triad of arthritis, uveitis, and skin rash. Sarcoidosis is mostly a diagnosis of exclusion made by demonstrating noncaseating granulomas at histopathologic examination in patients with compatible clinical and radiologic findings. Although sarcoidosis often affects the lungs and thoracic lymph nodes, it can involve almost any organ in the body. The most common radiologic manifestation is pulmonary involvement, characterized by mediastinal and bilateral symmetric hilar lymphadenopathies with perilymphatic micronodules. Abdominal involvement is also common in children and often manifests as hepatomegaly, splenomegaly, and abdominal lymph node enlargement. Although neurosarcoidosis and cardiac sarcoidosis are rare, imaging is essential to the diagnosis of central nervous system and cardiac involvement because of the risky biopsy procedure and its low diagnostic yield due to focal involvement. Being familiar with the spectrum of imaging findings of sarcoidosis may aid in appropriate diagnosis and management. ©RSNA, 2023 Test Your Knowledge questions are available in the supplemental material.

Uveitis Associated with Monogenic Autoinflammatory Syndromes in Children

Monogenic autoinflammatory syndromes (MAISs), are caused by pathogenic genetic variants in the innate immune system, leading to dysregulation and aberrant inflammasome activation spontaneously or with minimal triggering. The diagnosis and treatment of MAISs can be intricate, relying on an increased recognition of potential differential diagnoses. This review examines the clinical features of MAIS, with a special focus on uveitis. It also evaluates treatment options and assesses the effects of activating molecular and cytokine pathways.

Receptor Interacting Ser/Thr-Protein Kinase 2 as a New Therapeutic Target

Receptor interacting serine/threonine protein kinase 2 (RIPK2) is a downstream signaling molecule essential for the activation of several innate immune receptors, including the NOD-like receptors (NOD1 and NOD2). Recognition of pathogen-associated molecular pattern proteins by NOD1/2 leads to their interaction with RIPK2, which induces release of pro-inflammatory cytokines through the activation of NF-κB and MAPK pathways, among others. Thus, RIPK2 has emerged as a key mediator of intracellular signal transduction and represents a new potential therapeutic target for the treatment of various conditions, including inflammatory diseases and cancer. In this Perspective, first, an overview of the mechanisms that underlie RIPK2 function will be presented along with its role in several diseases. Then, the existing inhibitors that target RIPK2 and different therapeutic strategies will be reviewed, followed by a discussion on current challenges and outlook.

NF-κB and Related Autoimmune and Autoinflammatory Diseases

The NF-κB pathway is a cardinal signaling pathway that has been implicated in the development of a diverse range of clinical diseases. Numerous cellular processes converge on this pathway, which results in cell proliferation and survival. Defects in this pathway and in its upstream regulators have been described as causing immunodeficiency. However, there is a growing body of literature connecting autoimmune and autoinflammatory conditions to NF-κB pathway dysfunction. This review serves as a current appraisal of the literature of these disorders.

Case Report: Methotrexate and hydroxychloroquine in combination for the treatment of NOD2-mutation-associated Blau syndrome

Mutations in nucleotide binding oligomerization domain containing 2 receptor (NOD2) are associated with Blau syndrome (also known as early-onset sarcoidosis)-a rare autosomal dominant, chronic granulomatous disease that typically presents before 5 years of age. Blau syndrome is characterized by the clinical triad of arthritis, granulomatous dermatitis, and recurrent uveitis. Here, we report a case of NOD2-mutation-associated early-onset sarcoidosis in which a combination of methotrexate and hydroxychloroquine was used to achieve improvement in arthritis, granulomatous dermatitis, and uveitis. A 13-month-old boy presented with a sudden-onset cutaneous eruption affecting the face, trunk, and extremities that initially mimicked papular atopic dermatitis but progressively worsened despite topical steroid therapy. The patient had no other known medical comorbidities or abnormalities except for heterochromia of the right eye. However, prior to presentation to dermatology, the patient began experiencing frequent falls, conjunctival injection, and apparent eye and joint pain. Skin biopsy from the right shoulder demonstrated rounded aggregates of epithelioid histiocytes and multinucleated giant cells without a significant lymphocytic component ("naked granulomas"), consistent with sarcoidal granulomatous dermatitis. Given the concern for Blau syndrome, the patient was sent for evaluation by ophthalmology and was found to have bilateral subconjunctival nodules. Our patient underwent genetic testing and was found to have a mutation in codon 1000 C > T (protein R334W) in the NOD2 gene. The patient responded to oral prednisolone 2 mg/kg/day for 8 weeks, but quickly relapsed, requiring a second 8-week course with taper upon starting methotrexate 7.5 mg subcutaneously weekly with 1 mg folic acid orally daily. After 8 weeks on methotrexate, due to persistent arthritis, conjunctival injection, and pruritus, and in consultation with rheumatology, the patient was started on hydroxychloroquine 75 mg orally daily along with continuation of 7.5 mg methotrexate subcutaneously weekly for 8 weeks, achieving significant reduction in arthritis, pruritus, and uveitis. After 8 weeks of this combination therapy, due to concerns of long-term macular toxicity, hydroxychloroquine was discontinued in favor of continuing methotrexate alone. The patient has remained free of significant side effects and stable with good disease control on 7.5 mg methotrexate weekly injected subcutaneously.

Ocular sarcoidosis in adults and children: update on clinical manifestation and diagnosis

Sarcoidosis-associated uveitis, is the predominant ocular sarcoidosis presentation, which affects both adults and children. For adults, international ocular sarcoidosis criteria (IWOS) and sarcoidosis-associated uveitis criteria (SUN) are defined. However, for children they are not yet established internationally. Due to the specificity of pediatric manifestations of sarcoidosis, this task is even more challenging. In children, sarcoidosis is subdivided into Blau syndrome and early-onset sarcoidosis (BS/EOS) affecting younger children (< 5 years) and the one affecting older children with clinical presentation resembling adults. Differential diagnosis, clinical work-up as well as diagnostic criteria should be adapted to each age group. In this article, we review the clinical manifestation of sarcoidosis-associated uveitis in adults and children and the sensitivity and specificity of various ocular sarcoidosis diagnostic modalities, including chest X-ray and CT, FDG PET-CT, gallium-67 scintigraphy, bronchoalveolar lavage fluid, genetic testing for NOD2 mutations and serum biomarkers, such as ACE, lysozyme and IL2R.

Off-label use of canakinumab in pediatric rheumatology and rare diseases

Since the first success of interleukin-1 blockade in cryopyrin-associated periodic syndrome, the use of interleukin-1 inhibitors has expanded to other disorders, including off-label indications. In particular, canakinumab has been employed in an off-label fashion in several diseases such as rare monogenic autoinflammatory diseases and multifactorial autoinflammatory diseases, disclosing an excellent efficacy and good safety profile in pediatric patients unresponsive to standards of care. In addition, hyperferritinemic syndromes and complex disorders, as well as Kawasaki disease, uveitis, and other pediatric rare disorders, represent additional areas where canakinumab efficacy is worth exploring. Altogether, the results summarized below are of paramount importance in pediatric patients where a considerable proportion of treatments are prescribed off-label. This review focuses on the off-label use of canakinumab in pediatric patients affected by systemic immune-mediated diseases.

Incomplete penetrance of NOD2 C483W mutation underlining Blau syndrome

BACKGROUND

Blau syndrome (BS) is a rare autoinflammatory disorder with NOD2 gain-of-function mutation and characterized by autoactivation of the NFκB pathway. Classically considered a disease of high penetrance, reports on NOD2 mutations underlining BS with incomplete penetrance is limited.

CASE PRESENTATION

The proband is a 9-year-old girl presented with brownish annular infiltrative plaques and symmetric boggy polyarthritis over bilateral wrists and ankles. Her skin biopsy revealed noncaseating granulomas inflammation with multinucleated giant cells. A novel C483W NOD2 mutation was identify in the proband and her asymptomatic father. Functional examinations including autoactivation of the NFκB pathway demonstrated by in vitro HEK293T NOD2 overexpression test as well as intracellular staining of phosphorylated-NFκB in patient's CD11b⁺ cells were consistent with BS.

CONCLUSIONS

We reported a novel C483W NOD2 mutation underlining BS with incomplete penetrance. Moreover, a phosphorylated-NFκB intracellular staining assay of CD11b⁺ was proposed to assist functional evaluation of NFκB autoactivation in patient with BS.

The influence of age and sex in sarcoidosis

PURPOSE OF REVIEW

This review aims to describe how the clinical manifestations of sarcoidosis may be shaped by the effects of sex hormones and by age dependent changes in immune functions and physiology This review is intended to highlight the need to consider the effects of sex and sex in future studies of sarcoidosis.

RECENT FINDINGS

The clinical manifestations of sarcoidosis differ based on sex and gender There is emerging evidence that female and male hormones and X-linked genes are important determinants of immune responses to environmental antigens, which has important implications for granuloma formation in the context of sarcoidosis Furthermore, sex hormone levels predictably change throughout adolescence and adulthood, and this occurs in parallel with the onset immune senescence and changes in physiology with advanced age.

SUMMARY

Recent studies indicate that sex and age are important variables shaping the immune response of humans to environmental antigens We posit herein that sex and age are important determinants of sarcoidosis clinical phenotypes Many gaps in our understanding of the roles played by sex and gender in sarcoidosis, and these need to be considered in future studies.

Potential Benefits of TNF Targeting Therapy in Blau Syndrome, a NOD2-Associated Systemic Autoinflammatory Granulomatosis

Blau syndrome is a systemic autoinflammatory granulomatous disease caused by mutations in the nucleotide-binding oligomerization domain 2 (NOD2) gene. NOD2 is an intracellular pathogen recognition receptor. Upon binding to muramyl dipeptide (MDP), NOD2 activates the NF-κB pathway, leading to the upregulation of proinflammatory cytokines. Clinical manifestations of Blau syndrome appear in patients before the age of four. Skin manifestations resolve spontaneously in some cases; however, joint and eye manifestations are progressive, and lead to serious complications, such as joint contracture and blindness. Currently, there is no specific curative treatment for the disease. Administration of high-dose oral steroids can improve clinical manifestations; however, treatments is difficult to maintain due to the severity of the side effects, especially in children. While several new therapies have been reported, including JAK inhibitors, anti-IL-6 and anti-IL-1 therapies, anti-TNF therapy plays a central role in the treatment of Blau syndrome. We recently performed an ex vivo study, using peripheral blood and induced pluripotent stem cells from patients. This study demonstrated that abnormal cytokine expression in macrophages from untreated patients requires IFNγ stimulation, and that anti-TNF treatment corrects the abnormalities associated with Blau syndrome, even in the presence of IFNγ. Therefore, although the molecular mechanisms by which the genetic mutations in NOD2 lead to granuloma formation remain unclear, it is possible that prior exposure to TNFα combined with IFNγ stimulation may provide the impetus for the clinical manifestations of Blau syndrome.

Pediatric sarcoidosis with diagnostic and therapeutical insights

PURPOSE OF REVIEW

Sarcoidosis is a chronic granulomatous disorder involving multiple systems and organs of undefined etiology. Although most of the morbidity relies upon lung disease, the function of several systems and organs can be affected. The natural history of lung disease consists of pulmonary involvement. An exaggerated and abnormal inflammatory response accompanies this aspect. There are noncaseating confluent epithelioid granulomas and, potentially, a progressive airway obstruction ab externo. As the disease is multisystemic, there is an increased likelihood of complications that may be serious and even fatal.

RECENT FINDINGS

The American Thoracic Society (ATS) Core Curriculum updates clinicians annually in adult and pediatric lung disease, critical medical care, and sleep medicine. In late 2020, the ATS targeted sarcoidosis. Also, in 2019, the French Sarcoidosis Group thoroughly revised the literature on pediatric sarcoidosis. Currently, staging is based on chest radiograph findings, and the most commonly used system is the Scadding classification, which has been applied to both children and adults alike. Treatment may consist of oral or pulsed intravenous corticosteroids, but it should be implemented in union with a rheumatologist, as there are no randomized controlled studies in children.

SUMMARY

Sarcoidosis is rare in childhood. Diagnosis is complex and relies on multiple diagnostic modalities with both staging and therapy progressively mirroring the sarcoidosis, which affects adults. In the majority of patients, spontaneous resolution will occur and observation is justified above treatment. Nevertheless, in case treatment is needed corticosteroids remain the mainstay of the treatment in some pediatric patients. Relapses are not uncommon and a long-term follow-up is essential.

Multimodal imaging in pediatric uveitis

Pediatric uveitis accounts for up to 10% of all uveitis cases, so special attention must be paid to ensure early diagnosis as well as treatment and follow-up of these young patients in order to decrease the risk of possible ocular complications and consequently vision loss. Multimodal imaging has been an effective and important adjunct in the diagnoses and management of uveitis, especially in children. Reviewed here are the currently utilized modalities, advances, as well as their applications in juvenile idiopathic arthritis-associated uveitis, pars planitis, retinal vasculitis, tubulointerstitial nephritis and uveitis syndrome, Behçet disease, Blau syndrome, and Vogt-Koyanagi-Harada syndrome.