Blau syndrome with good Reponses to Tocilizumab: A case report and focused literature review

[Monogenic autoinflammatory uveitis]

Monogenic autoinflammatory uveitis belongs to the spectrum of monogenic autoinflammatory diseases. When early-onset uveitis is associated with specific extra-ocular manifestations, particularly in a familial or geographical context, it guides the clinician towards a diagnosis of a monogenic autoinflammatory disease. The clinical presentation and mode of inheritance will help identify the underlying cause, and the detection of a pathogenic variant will confirm the diagnosis and guide the management approach. In this review, we outline the main monogenic autoinflammatory uveitis conditions that clinicians should be aware of: Blau syndrome, ROSAH syndrome, cryopyrin-associated periodic syndromes (CAPS), partial mevalonate kinase deficiency, A20 haploinsufficiency, and NEMO syndrome.

Long-Term Visual Outcome of Patients with Blau Syndrome

PURPOSE

To document the long-term visual outcomes in patients with Blau syndrome.

METHODS

A retrospective institutional cohort study was conducted, and 13 patients with genetically confirmed Blau syndrome were included. Demographic and clinical data were collected from standardised medical charts. Baseline was defined as the first detected uveitis and data were recorded onwards at intervals of 1, 3, 5, 10, 15 and 20 years.

RESULTS

Anterior uveitis was the most common classification at baseline (57.1%). Among patients with documented uveitis lasting 10 years or more, all of them developed panuveitis. Median logMAR visual acuity at baseline was 0 (range -0.5; 0.7), 0.19 (range 0; 1.5) at year 5, and 0.7 (range 0.1 - no perception of light) at year 20, as recorded in 13, 16, and 10 eyes, respectively. All patients received treatment with topical and oral steroids, and multiple systemic immunosuppressants including biologics. Disease control, defined as having cells <1+ in both eyes and using topical steroid eye drops less than twice daily, was achieved in 14.3% to 37.5% of patients at the different time points. Cataract surgery was performed in 12 eyes of 8 patients, 3 eyes of 3 patients necessitated glaucoma surgery, and 4 eyes of 4 patients required surgery for retinal detachment.

CONCLUSION

Uveitis associated with Blau syndrome commonly leads to severe, chronic panuveitis, requiring long-term systemic immunosuppression. Early diagnosis and timely initiation of biologics may prevent significant visual impairment.

Granulomatous Tubulointerstitial Nephritis in a Kidney Allograft: Treatment with Interleukin-6 Receptor Antagonist Stabilises Kidney Function

Granulomatous tubulointerstitial nephritis (GTIN) attributed to early onset sarcoidosis is an ultrarare finding in an allograft kidney biopsy. We present the case of a young man with allograft dysfunction who had GTIN upon biopsy. We performed a thorough case review based on recovered records from early childhood and reassessed genetic testing results. We revised his underlying diagnosis from cryopyrin-associated periodic syndrome to early-onset sarcoidosis with wild-type NOD2 and established a rationale to use the interleukin-6 (IL-6) receptor blocker tocilizumab (TCZ). This suppressed his inflammatory disease and stabilised kidney function. We performed a literature review related to the emerging role of IL-6 pathway blockade in kidney transplantation. We identified 18 reports with 417 unique patients treated with TCZ for indications including HLA-desensitisation, transplant immunosuppression induction, treatment of chronic antibody-mediated rejection, and treatment of subclinical rejection. Both TCZ and the direct IL-6 inhibitor clazakizumab are being studied in ongoing randomised control trials.

Blau Syndrome With Delayed Cutaneous Manifestations: A Case Report

ABSTRACT

Blau syndrome is a rare familial autoinflammatory disorder characterized by the triad of granulomatous dermatitis, polyarthritis, and uveitis. Blau syndrome exhibits an autosomal dominant inheritance pattern and can be caused by a gain-of-function mutation in nucleotide-binding oligomerization domain 2 (NOD2), a member of the NOD-like receptor family of pattern recognition receptors. Mutations in NOD2 cause upregulation of inflammatory cytokines and resultant autoinflammation. Because of the rarity of this condition and early onset of symptoms, Blau syndrome may be misdiagnosed as juvenile idiopathic arthritis. We present a case of a 37-year-old male patient with a long-documented history of juvenile idiopathic arthritis and uveitis, who developed an asymptomatic eruption of pink papules on the trunk and upper extremities. A biopsy demonstrated noncaseating, well-formed dermal granulomas with relatively sparse lymphocytic inflammation and Langerhans-type giant cells. Genetic testing confirmed a mutation in NOD2. Based on the patient's clinical history, histologic findings, genetic testing, the diagnosis of Blau syndrome was made.

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.

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.

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.

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.

Molecularly Targeted Therapies for Inflammatory Cutaneous Granulomatous Disorders: A Review of the Evidence and Implications for Understanding Disease Pathogenesis

Inflammatory cutaneous granulomatous diseases, including granuloma annulare, cutaneous sarcoidosis, and necrobiosis lipoidica, are distinct diseases unified by the hallmark of macrophage accumulation and activation in the skin. There are currently no Food and Drug Administration-approved therapies for these conditions except prednisone and repository corticotropin injection for pulmonary sarcoidosis. Treatment of these diseases has generally been guided by low-quality evidence and may involve broadly immunomodulatory medications. Development of new treatments has in part been limited by an incomplete understanding of disease pathogenesis. Recently, there has been substantial progress in better understanding the molecular pathogenesis of these disorders, opening the door for therapeutic innovation. Likewise, reported outcomes of treatment with immunologically targeted therapies may offer insights into disease pathogenesis. In this systematic review, we summarize progress in deciphering the pathomechanisms of these disorders and discuss this in the context of emerging evidence on the use of molecularly targeted therapies in treatment of these diseases.

Pathogenesis and current therapies for non-infectious uveitis

Non-infectious uveitis (NIU) is a disorder with various etiologies and is characterized by eye inflammation, mainly affecting people of working age. An accurate diagnosis of NIU is crucial for appropriate therapy. The aim of therapy is to improve vision, relieve ocular inflammation, prevent relapse, and avoid treatment side effects. At present, corticosteroids are the mainstay of topical or systemic therapy. However, repeated injections are required for the treatment of chronic NIU. Recently, new drug delivery systems that may ensure intraocular delivery of therapeutic drug levels have been highlighted. Furthermore, with the development of immunosuppressants and biologics, specific therapies can be selected based on the needs of each patient. Immunosuppressants used in the treatment of NIU include calcineurin inhibitors and antimetabolites. However, systemic immunosuppressive therapy itself is associated with adverse effects due to the inhibition of immune function. In patients with refractory NIU or those who cannot tolerate corticosteroids and immunosuppressors, biologics have emerged as alternative treatments. Thus, to improve the prognosis of patients with NIU, NIU should be managed with different drugs according to the response to treatment and possible side effects.

Blau syndrome with hypertension and hepatic granulomas: a case report and literature review

Background

Blau syndrome (BS) is a monogenic disorder caused by NOD2 gene variants characterized by the triad of granulomatous polyarthritis, rash, and uveitis. Atypical symptoms were recognized in one-third to one-half of individuals with BS. This study aims to describe the clinical features of BS patients with hypertension and digestive system involvement.

Methods

The complete clinical data of a BS patient complicated with hypertension and hepatic granulomas were collected and documented. We also performed a literature search to find all reported cases of BS with hypertension and digestive system involvement.

Results

We reported the case of a 19-year-old man who presented with early onset symmetric polyarthritis and hypertension at age 5 and hepatic granulomas and cirrhosis at age 19. He was diagnosed with BS by the finding of a variant of the NOD2 gene (R334W). Through the literature review, 24 patients with BS were found who were reported to have hypertension, and 38 patients were found who had different digestive system manifestations such as hepatic granulomas, hepatosplenomegaly, diverticulitis, and intestinal granuloma. Among the 38 BS patients with digestive system involvement, 14 had hepatic granulomas proven by liver biopsy.

Conclusions

Hypertension and digestive system involvement are rare manifestations of BS. Clinicians, especially rheumatologists, must be aware of atypical symptoms of BS.

Corneal Ulcers with NOD2 Mutations Presenting with Mixed Syndromic Phenotype

PURPOSE

To report a case of corneal ulcers in a patient with NOD2 mutations unique to but phenotypically resembling well-characterized syndromic phenotypes like Blau syndrome.

OBSERVATION

A 25-year-old female with a medical history of type I diabetes mellitus, Asperger syndrome, and neuropathy presented with bilateral corneal ulcers. Her visual acuity was 20/200 OU. Macular edema was identified OS, and posterior synechiae OS suggested a history of anterior uveitis.Genetic testing confirmed NOD2 mutations, and her tear film was positive for matrix metallopeptidase 9. Recent intravenous immunoglobulin therapy improved her neuropathy, and an aggressive regimen of erythromycin ointment and lubrication has improved her ophthalmic symptoms.

CONCLUSION AND IMPORTANCE

This case advances our understanding of NOD2's role in regulating inflammatory processes of the eye. In addition to precipitating uveitis, patients with these mutations may also be at increased risk of developing corneal pathology related to their reduced capacity to moderate inflammatory processes.

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.

Biologic Therapies for the Management of Cutaneous Findings in Genodermatoses: A Review

Genodermatoses are genetically inherited dermatologic conditions. The management of cutaneous findings in genodermatoses is challenging, and first-line therapies, such as steroids and/or retinoids, are often inadequate. In recent years, research on the molecular basis of genodermatoses has led to the use of biologic therapies for intractable disease. Here, we review the evidence regarding the use of available biologic therapies for the management of dermatologic findings in genodermatoses. Biologic therapies appear to be promising therapeutic options for several recalcitrant genodermatoses, especially those with underlying immune dysregulation. However, not all genodermatoses are amenable to biologic therapies, and some have been shown to paradoxically worsen under treatment. Biologic therapies offer a novel avenue to target refractory genodermatoses. However, evidence supporting the use of biologic therapies in the management of genodermatoses is mostly limited to case reports and case series. Further studies are warranted to determine the safety and efficacy of biologic therapies for the management of cutaneous findings in genodermatoses.

Induced Pluripotent Stem Cell-Derived Monocytes/Macrophages in Autoinflammatory Diseases

The concept of autoinflammation, first proposed in 1999, refers to a seemingly unprovoked episode of sterile inflammation manifesting as unexplained fever, skin rashes, and arthralgia. Autoinflammatory diseases are caused mainly by hereditary abnormalities of innate immunity, without the production of autoantibodies or autoreactive T cells. The revolutionary discovery of induced pluripotent stem cells (iPSCs), whereby a patient’s somatic cells can be reprogrammed into an embryonic pluripotent state by forced expression of a defined set of transcription factors, has the transformative potential to enable in vitro disease modeling and drug candidate screening, as well as to provide a resource for cell replacement therapy. Recent reports demonstrate that recapitulating a disease phenotype in vitro is feasible for numerous monogenic diseases, including autoinflammatory diseases. In this review, we provide a comprehensive overview of current advances in research into autoinflammatory diseases involving iPSC-derived monocytes/macrophages. This review may aid in the planning of new studies of autoinflammatory diseases.

Clinical and immunological study of Tofacitinib and Baricitinib in refractory Blau syndrome: case report and literature review

Blau syndrome (BS) is an autoinflammatory disorder characterized by non-caseating granulomatous dermatitis, arthritis, and uveitis. We present a case of refractory and severe BS that was treated with the Janus kinase inhibitors (JAKINIBS), Tofacitinib (TOFA) and then Baricitinib (BARI). Our aim was to describe the clinical and immunological outcomes after treatment with JAKINIBS. Blood tests and serum samples were obtained during follow-up with TOFA and BARI. We assessed their effects on clinical outcomes, acute phase reactants, absolute lymphocyte counts (ALCs), lymphocyte subset counts, immunoglobulins, and cytokine levels. A review of the literature on the use of JAKINIBS for the treatment of uveitis and sarcoidosis was also conducted. TOFA led to a rapid and maintained disease control and a steroid-sparing effect. A decrease from baseline was observed in ALC, CD3+, CD4+, CD8+, and natural killer (NK) cell counts. B-cells were stable. Serum levels of interleukin (IL)-4 and tumor necrosis factor alpha (TNF-α) increased, whereas IL-2, IL-6, IL-10, and IL-17 maintained stable. TOFA was discontinued after 19 months due to significant lymphopenia. The initiation of BARI allowed maintaining adequate control of disease activity with an adequate safety profile. The literature review showed seven patients with uveitis and five with sarcoidosis treated with JAKINIBS. No cases of BS treated with JAKINIBS were found. We report the successful use of JAKINIBS in a patient with refractory and severe BS.

Ocular involvement in monogenic autoinflammatory disease

OBJECTIVE

Monogenic Autoinflammatory diseases (AIDs) are a broad spectrum of rare hereditary diseases whose ocular involvement has not been well characterized yet. This systematic review aims to provide an overview of the current knowledge about ocular findings in AIDs.

METHODS

A systematic literature review was conducted using 2 electronic databases, according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A combination of AIDs and ophthalmology-related search terms were used. All articles were screened by 2 independent reviewers for title, abstract and full text level. We included solely studies that investigated ocular findings in AIDs.

RESULTS

198 papers of 4268 records were retained. Data about 1353 patients with a diagnosis of autoinflammatory disease and ocular involvement were collected (680 CAPS, 211 FMF, 138 TRAPS, 238 Blau, 32 MKD, 21 SIFD, 7 Aicardi Goutières, 3 CANDLE, 8 DADA2, 9 HA20, 6 APLAID). Conjunctivitis was significantly more frequent in CAPS (p < 0.00001), uveitis in Blau, MKD, HA20 and CANDLE (p < 0.00001), papillitis/papilledema in CAPS (p < 0.00001), optic neuritis in Aicardi and DADA2 (p < 0.008), retinal vasculitis in FMF (p < 0.00001), progressive reduction in choroidal thickness in FMF and DADA2 (p < 0.00001), periorbital oedema in TRAPS (p < 0.00001) and retinitis in SIFD (p < 0.00001). Among AIDs with uveitis, granulomatous inflammation was more common in Blau syndrome (p < 0.00001).

CONCLUSION

This systematic literature review characterized the ocular involvement of several AIDs, and the present data may encourage to consider a timely ophthalmological screening program for these rare diseases.

Anti-TNF treatment corrects IFN-γ-dependent proinflammatory signatures in Blau syndrome patient-derived macrophages

BACKGROUND

Blau syndrome (BS) is an autoinflammatory disease associated with mutations in nucleotide-binding oligomerization domain 2. Although treatments with anti-TNF agents have been reported to be effective, the underlying molecular mechanisms remain unclear.

OBJECTIVE

We aimed to elucidate the mechanisms of autoinflammation in patients with BS and to clarify how anti-TNF treatment controls the disease phenotype at the cellular level in clinical samples.

METHODS

Macrophages were differentiated from monocytes of 7 BS patients, and global transcriptional profiles of 5 patients were analyzed with or without IFN-γ stimulation. Macrophages were also generated from BS-specific induced pluripotent stem cells (iPSCs), and their transcriptome was examined for comparison.

RESULTS

Aberrant inflammatory responses were observed upon IFN-γ stimulation in macrophages from untreated BS patients, but not in those from patients treated with anti-TNF. iPSC-derived macrophages carrying a disease-associated mutation also showed IFN-γ-dependent accelerated inflammatory responses. Comparisons of peripheral blood- and iPSC-derived macrophages revealed the upregulation of nuclear factor kappa-light-chain enhancer of activated B cells (NF-κB) targets in unstimulated macrophages as a common feature.

CONCLUSIONS

IFN-γ stimulation is one of the key signals driving aberrant inflammatory responses in BS-associated macrophages. However, long-term treatment with anti-TNF agents ameliorates such abnormalities even in the presence of IFN-γ stimulation. Our data thus suggest that preexposure to TNF or functionally similar cytokines inducing NF-κB-driven proinflammatory signaling during macrophage development is a prerequisite for accelerated inflammatory responses upon IFN-γ stimulation in BS.

Blau syndrome with pulmonary nodule in a child

Blau syndrome (BS) is a rare monogenic disease caused by mutation of NOD2/CARD15 gene. A case of Blau syndrome in a 4-year-old Chinese boy c.1001G > A(p.R334Q) mutation in the NOD2 genes reported. Imaging revealed a nodule at the tip of the right lung.

First report of liver transplantation in Blau syndrome: The challenges faced in this rare granulomatous liver disease

Blau syndrome is a rare autoinflammatory granulomatous disease caused by variants in the NOD2 gene, classically presenting in childhood. Hepatic manifestations are recognized including cholestasis and granulomatous liver disease. We describe a novel NOD2 gene variant c.1471A > C, p.(Met491Leu) in an adult who developed cirrhotic complications despite selective immunotherapy, including recurrent esophageal bleeding and spontaneous bacterial peritonitis which resulted in liver transplantation. He required a second liver transplant as his first graft failed due to ischemic cholangiopathy. Disease recurrence has been observed (hitherto unreported). Of 84 patients with Blau syndrome treated with antibody therapy, five hepatic cases responded to anti-TNF therapy, with promising results if instigated before decompensation occurs. We report the first case of liver transplantation for Blau syndrome in an adult with a novel NOD2 variant. Blau related liver disease can reoccur post transplantation and is an important consideration for any future graft. LAY SUMMARY: Blau syndrome is a rare immune disease which presents in childhood. We describe the first liver transplant for this condition following development of progressive liver disease in adulthood. The patient had a newly described variant in the Blau gene (NOD2). We discuss the effectiveness of antibody therapy currently being used to control the disease, and the role of liver transplantation in Blau syndrome.

Distinguishing Blau Syndrome from Systemic Sarcoidosis

PURPOSE OF REVIEW

The purpose of this review is to provide a framework to distinguish Blau syndrome/Early Onset Sarcoidosis and Sarcoidosis clinically. We also discuss relevant differences in genetics, pathogenesis, and management of these diseases.

RECENT FINDINGS

Blau syndrome and Sarcoidosis share the characteristic histologic finding of noncaseating granulomas as well as some similar clinical characteristics; nevertheless, they are distinct entities with important differences between them. Blau syndrome and Early Onset Sarcoidosis are due to one of numerous possible gain-of-function mutations in NOD2, commonly presenting before age 5 with a triad of skin rash, arthritis, and uveitis. However, as more cases are reported, expanded clinical manifestations have been described. In systemic Sarcoidosis, there are numerous susceptibility genes that have been identified, and disease is thought to result from an environmental exposure in a genetically susceptible host. It most often presents with constitutional symptoms and pulmonary involvement and typically affects adolescents and adults. This paper reviews the similarities and differences between Blau syndrome and Sarcoidosis. We also discuss the importance of distinguishing between them, particularly with regard to prognosis and outcomes.

Ocular manifestations of Blau syndrome

PURPOSE OF REVIEW

This article summarizes the systemic and ocular manifestations of Blau syndrome, its genetic basis, and reviews recently published literature.

RECENT FINDINGS

A large multicenter prospective case series is underway, with 3-year preliminary results indicating the prevalence of uveitis, clinical characteristics and early data on its visual prognosis. Case reports have demonstrated the successful use of newer biologic agents.

SUMMARY

Blau syndrome is an exceedingly rare autoinflammatory disorder with skin, joint and eye manifestations. It is caused by autosomal dominant mutations of the NOD2 protein. Eye involvement is typically a chronic bilateral granulomatous iridocyclitis, often with multifocal choroiditis in the posterior segment. Treatment starts with topical and systemic steroids and often requires antimetabolites or biologic agents.

Whole-exome sequencing in three children with sporadic Blau syndrome, one of them co-presenting with recurrent polyserositis

Blau syndrome (BS) is a rare, chronic autoinflammatory disease with onset before age 4 and mainly characterised by granulomatous arthritis, recurrent uveitis, and skin rash. Sporadic (also known as early-onset sarcoidosis) or familial BS is caused by gain-of-function mutations in the NOD2 gene, which encodes for a multi-task protein that plays a crucial role in the innate immune defense. We report on three Mexican patients clinically diagnosed with BS who exhibited a likely pathogenic variant in NOD2 as revealed by whole-exome sequencing (WES) and Sanger sequencing: two variants (c.1000 C > T/p.Arg334Trp and c.1538 T > C/p.Met513Thr) lie in the ATP/Mg2+ binding site, whereas the other (c.3019dupC/p.Leu1007ProfsTer2) introduces a premature stop codon disrupting the last LRR domain (LRR9) formation; all three variants are consistent with gain-of-function changes. Interestingly, all these patients presented concomitant likely pathogenic variants in other inflammatory disease-related genes, i.e. TLR10, PRR12, MEFV and/or SLC22A5. Although the clinical presentation in these patients included the BS diagnostic triad, overall it was rather heterogeneous. It is plausible that this clinical variability depends partly on the patients' genetic background as suggested by our WES results. After this molecular diagnosis and given the absence of NOD2 mutations (demonstrated in two trios) and related symptoms in the respective parents (confirmed in all trios), patients 1 and 2 were considered to have sporadic BS, while patient 3, a sporadic BS-recurrent polyserositis compound phenotype. Altogether, our observations and findings underscore the overlapping among inflammatory diseases and the importance of determining the underlying genetic cause by high-throughput methods. Likewise, this study further reinforces a pathogenic link between the here found NOD2 variants and BS and envisages potential additive effects from other loci in these, and probably other patients.

Ophthalmological treatment of early-onset sarcoidosis/Blau syndrome in a Colombian child: A case report

Purpose

To report the ophthalmological approach of a patient with Blau syndrome (BS) in Colombia.

Observations

We describe a 9-year-old Colombian boy with sporadic BS due to a de novo nucleotide-binding oligomerization domain containing 2 (NOD2) mutation, who presented with joint and dermatologic symptoms. He was referred to the uveitis service with a single functional eye, due to retinal detachment in the other eye. Despite treatment with corticosteroids, methotrexate, and adalimumab, the patient continued to exhibit progressive disease.

Conclusion

BS-related uveitis is characterized by severe ocular morbidity. Appropriate interdisciplinary treatment is necessary for the correct identification and management of the disease, considering the inherent difficulty in its diagnosis due to its diverse clinical manifestations. The severity of BS-related uveitis in this report highlights the need for more effective therapies.

The expanding pathways of autoinflammation: a lesson from the first 100 genes related to autoinflammatory manifestations

AutoInflammatory Diseases (AIDs) are a group of innate immune system disorders characterized by sterile inflammation without evidence of pathogenic autoantibodies or auto-reactive T lymphocytes. An expanding spectrum of genes and molecular pathways are associated with AIDs. Inflammasomopathies are secondary to dysregulation of multi-protein complexes, called inflammasomes, leading to an excessive maturation and secretion of IL1β and IL18. Patients present with persistent or recurrent systemic inflammation, abdominal and chest pain, skin rashes and are sensible to IL1 inhibitors. Unfolded proteins response causes a small number of AIDs that we propose to call immuno-proteinopathies, characterized by recurrent fevers and deep tissues inflammation. Other inflammatory conditions can occur in case of abnormalities of actin polymerization and the term of immuno-actinopathies is proposed. Generalized pustular psoriasis is a marker of autoinflammation mainly affecting the keratinocytes. Specific treatment targeting the p40 subunit of IL12 and IL23 or IL-17 are usually effective. Granulomatous inflammation characterizes AIDs related to NOD2 signaling defects. Defects in the ubiquitin-proteasome system cause a group of relopathies and some interferonopathies related to defect of the proteasome function (CANDLE syndrome). Gain of function of proteins regulating the production of type I interferons lead to severe inflammatory conditions, called interferonopathies. The JAK/STAT inhibitors are usually effective in these latter conditions. In conclusions, the identification of the main intracellular pathways involved in rare monogenic AIDs allows not only the proper classification of different conditions, but also highlight a pivotal role of possible novel therapeutic targets for the future.

Clinical and genetic features of Chinese adult patients with tumour necrosis factor receptor-associated periodic fever syndrome

Objectives

TNF receptor-associated periodic fever syndrome (TRAPS) is an autosomal dominant systemic autoinflammatory disease caused by mutations of TNF receptor superfamily member 1 A (TNFRSF1A) gene. TRAPS has hardly been reported in the Chinese population. We aimed to characterize the clinical and genetic features of Chinese adult patients with TRAPS.

Methods

Nine adult patients (≥16 years) were diagnosed during April 2015 to June 2019, at the Department of Rheumatology, Peking Union Medical College Hospital. Clinical and genetic features of these patients were evaluated and compared with those from Japan and Europe.

Results

The median age of disease onset was 3 (0.5–38.5) years old, and adult-onset was observed in two (22.2%) patients. The median time of diagnosis delay was 16.5 (1.5–50.5) years. One patient had a family history of TRAPS. The frequent symptoms were fever (nine, 100%), rash (seven, 77.8%), arthralgia/arthritis (five, 55.6%) and abdominal pain (five, 55.6%). Only two (22.2%) patients had periorbital oedema. Nine TNFRSF1A gene variants were detected, including C58R, G65E, F89L, C99G, V202G, V202D, c.769-23T&gt;C, S290I and c.*64T&gt;C. Rash was more frequently seen in Chinese than in Japanese and European patients, while chest pain and amyloidosis occurred less frequently.

Conclusion

This is the first and largest case series of TRAPS in Chinese adult patients. Two novel TNFRSF1A variants, S290I and V202G, have been identified. The different clinical manifestations of our patients compared with those from Japan and Europe might be related to their TNFRSF1A variants.

Effective treatment of TNFα inhibitors in Chinese patients with Blau syndrome

Objectives

Blau syndrome (BS) is a rare dominantly inherited autoinflammatory disorder associated with mutations in the nucleotide-binding oligomerization domain containing 2 (NOD2) gene. Biologic therapy of BS yielded diverse results. We aimed to evaluate clinical features and outcomes of Chinese patients with BS who were treated with tumor necrosis factor (TNF)α inhibitors.

Methods

A total of four patients with BS were diagnosed and treated with infliximab (IFX) at the Peking Union Medical College Hospital during 2015 to 2018 and were followed up for 18 months. All patients were systematically studied for treatment outcomes including the clinical manifestations and inflammatory markers. We also conducted a comprehensive literature review about TNFα inhibitor therapy in BS.

Results

Four BS patients were all Chinese Han, and three were women. The mean age of disease onset was 4 ± 3.5 years, and the mean time of diagnosis delay was 19 ± 11 years. All patients received IFX plus methotrexate, and all achieved clinical remission of skin lesions and polyarthritis rapidly, as well as normalization of erythrocyte sedimentation rate and C-reactive protein and improvements in inflammatory cytokines, patient visual analogue scale, physician global assessment, and Short Form (SF)-36, at the first follow-up of 6 months. The disease relapsed in two patients after they lengthened the interval of IFX and discontinued methotrexate. According to the 38 English-language publications, 62 patients with BS were reported who underwent TNFα inhibitor therapy, including IFX used in 31, adalimumab in 24, and etanercept in 7. IFX was well tolerated in 27 patients, while 2 still had uveitis, and the other 2 experienced an adverse drug reaction.

Conclusions

Early recognition and effective treatment of BS are very important to avoid irreversible organ damage. TNFα inhibitors such as IFX may be a promising approach for BS patients who have unsatisfactory response to corticosteroids and traditional disease-modifying antirheumatic drugs.

Blau Syndrome and Early-Onset Sarcoidosis: A Six Case Series and Review of the Literature

Objectives

This study aims to discuss the clinical, laboratory and genetic findings, and treatment options for six patients who were diagnosed with Blau syndrome (BS)/early-onset sarcoidosis (EOS).

Patients and methods

The study included four patients (2 males,2 females; mean age 7 years; range 4 to 10 years) with EOS and two siblings (1 male, 1 female; mean age 10 years; range, 9 to 11 years) with BS. Age, age of initial symptoms, age of diagnosis; articular involvement, presence of uveitis, dermatitis, or fever, other organ involvement, laboratory findings, results of metabolic tests for mucopolysaccharidosis and mucolipidosis, results of genetic, pathologic, and immunologic tests, radiologic findings to evaluate skeletal dysplasia, and treatment options were collected.

Results

The median age at diagnosis of all patients was 6 years (range, 1 to 10 years). Five patients had camptodactyly and bilateral boggy synovitis in the wrists and ankles, one had granulomatous inflammatory changes in the liver and kidney biopsy, and one had attacks of fever and granulomatous dermatitis. None had uveitis. The detected mutations in nucleotide-binding oligomerization domain containing 2 (NOD2) were P268S (rs2066842), M513T (rs104895473), R702W (rs2066844), V955I (rs5743291), H343Y (rs199858111), and M491L (16:50745293). The treatments of patients included corticosteroids, non-steroid anti-inflammatory drugs, methotrexate, infliximab, adalimumab, anakinra, and canacinumab.

Conclusion

Camptodactyly and boggy synovitis are important signs of BS/EOS. Methotrexate and tumor necrosis factor blockers are more effective in patients with predominantly articular symptoms. In patients 5 and 6 and their mother, we determined a novel M491L mutation in the NOD2 gene. Currently, this work is in progress towards identifying the pathogenesis and treatment options for this disease.

Autoinflammatory Disorders: A Review and Update on Pathogenesis and Treatment

The autoinflammatory diseases comprise a broad spectrum of disorders characterized by unchecked activation of the innate immune system. Whereas aberrations in adaptive immunity have long been identified in 'autoimmune' disorders, the concept of 'autoinflammation' emerged relatively recently, first describing a group of clinical disorders characterized by spontaneous episodes of systemic inflammation without manifestations typical of autoimmune disorders. Improved knowledge of innate immune mechanisms, coupled with remarkable progress in genomics and an expanding number of clinical cases, has since led to an increasing number of disorders classified as autoinflammatory or containing an autoinflammatory component. Biologic therapies targeting specific components of the innate immune system have provided immense clinical benefit, and have further elucidated the role of innate immunity in autoinflammatory disorders. This article reviews the basic mechanisms of autoinflammation, followed by an update on the pathophysiology and treatment of the monogenic and multifactorial autoinflammatory diseases, and the common dermatologic conditions in which autoinflammation plays a major role.

Autoinflammatory disease with focus on NOD2-associated disease in the era of genomic medicine

Systemic autoinflammatory diseases (SAIDs) represent a spectrum of genetically heterogeneous inflammatory disorders. Some SAID-associated genes are located in chromosome 16, including familial Mediterranean fever gene (MEFV) and nucleotide-binding oligomerization domain 2 [NOD2] gene that are linked to Crohn's disease, Blau syndrome, and Yao syndrome. These disorders share overlapping clinical phenotypes, and genotyping is diagnostically helpful and distinctive. Using next generation sequencing in SAIDs, digenic variants or combinations of more genetic variants in different genes can be detected, and they may be related to the MEFV and NOD2 genes. These variants may contribute to heterogeneous phenotypes in an individual, complicating the diagnosis and therapy. An awareness of the clinical significance of the digenic or combined gene variants is important in the era of genomic medicine.

Biologics for the treatment of noninfectious uveitis: current concepts and emerging therapeutics

PURPOSE OF REVIEW

There is mounting evidence supporting the use of biologic therapeutics for the management of noninfectious uveitis (NIU). This review highlights: biologics with documented efficacy in NIU; agents with ongoing evaluation for efficacy in uveitis; and therapeutics for which investigation for efficacy in NIU is warranted.

RECENT FINDINGS

The tumor necrosis factor-alpha (TNF-α) inhibitor adalimumab has recently gained approval by the Food and Drug Administration for the treatment of noninfectious intermediate, posterior, and panuveitis. There is mounting evidence supporting the use of tocilizumab and rituximab in NIU. There is developing interest in evaluating the interleukin (IL)-23 inhibitors for efficacy in NIU.

SUMMARY

The TNF-α inhibitors adalimumab and infliximab have the greatest body of data supporting their use in NIU. These agents are considered second-line therapy for most forms of NIU but may be considered first-line therapy for uveitis associated with Behçet's disease and juvenile idiopathic arthritis. The B-cell inhibitor rituximab and the IL-6 inhibitor tocilizumab also have documented efficacy in NIU. Tocilizumab and interferon therapy may be particularly efficacious in the management of uveitic macular edema. The IL-23 inhibitors and janus kinase inhibitors are agents whose efficacy in NIU will likely be determined in the near future.

Giant Cell Tumor of Tendon Sheath and Tendinopathy as Early Features of Early Onset Sarcoidosis

Giant cell tumor of tendon sheath (GCTTS) is characterized by diffuse proliferation of synovial-like cells and multinucleated giant cells along tendon sheaths. This benign tumor typically presents in the third to fourth decade of life and is exceeding rare in children. Here we describe a case of a 10-years-old girl with a history of soft tissue swelling involving the third digit of left hand, bilateral wrists and ankles. Pathology of the finger mass revealed abundant multinucleated giant cells consistent with GCTTS. Resection of the tendinous masses from the ankles also showed multinucleated giant cells along with chronic bursitis. She began to show features of polyarticular arthritis by age 7. Due to progression of arthritis, whole exome sequencing was performed and found a de novo heterozygous mutation in NOD2 (p. R334Q). This variant is the most common mutation responsible for early onset sarcoidosis (EOS)/Blau syndrome, an autoinflammatory disease characterized by granulomatous inflammation of joints, skin and eyes. The early onset of symptoms and presence of multinucleated giant cells and granuloma in this case are in keeping with a diagnosis of EOS/Blau syndrome. The patient responded well to treatment with methotrexate and etanercept. This case extends the clinical spectrum of EOS/Blau syndrome, which should be considered for GCTTS and other unusual presentations of tendon inflammation in children, even in the absence of the characteristic triad of arthritis, dermatitis and uveitis.

New autoinflammatory diseases

PURPOSE OF REVIEW

Advances in sequencing techniques and systematic cohort-analysis of patients with autoinflammatory phenotypes have enabled a burst in the recognition of new autoinflammatory diseases and contributed to the description of the mechanisms involved in autoinflammation. This review focuses on new genetic and mechanistic discoveries that have broadened the definition of autoinflammatory diseases in the context of the established landscape, providing new therapeutic opportunities and avenues for further discoveries.

RECENT FINDINGS

Mechanistic insights of inflammatory diseases open opportunities for new targeted therapies. Advances in high-throughput screening of small-molecule inhibitors accelerate the discovery of new and more specific therapeutic options. Recent evidence establishes IL-18 as a driver of macrophage activation, emerging as a new biomarker and therapeutic target. Finally, the identification of escape of nonsense-mediated decay as the genetic mechanism resulting in a monogenic immune-dysregulatory disease, unveils a possibility for future discoveries.

SUMMARY

Recent mechanistic findings in autoinflammatory diseases as well as the identification of specific biomarkers and discovery of new diseases, continue to pave the way for ever more specific targeted approaches. These therapies are not only applicable to monogenic autoinflammatory syndromes but also for other diseases in which the same pathways are dysregulated.

The Two-Faced Cytokine IL-6 in Host Defense and Diseases

Interleukein-6 (IL-6), is produced locally from infectious or injured lesions and is delivered to the whole body via the blood stream, promptly activating the host defense system to perform diverse functions. However, excessive or sustained production of IL-6 is involved in various diseases. In diseases, the IL-6 inhibitory strategy begins with the development of the anti-IL-6 receptor antibody, tocilizumab (TCZ). This antibody has shown remarkable effects on Castleman disease, rheumatoid arthritis and juvenile idiopathic arthritis. In 2017, TCZ was proven to work effectively against giant cell arteritis, Takayasu arteritis and cytokine releasing syndrome, initiating a new era for the treatment of these diseases. In this study, the defensive functions of IL-6 and various pathological conditions are compared. Further, the diseases of which TCZ has been approved for treatment are summarized, the updated results of increasing off-label use of TCZ for various diseases are reviewed and the conditions for which IL-6 inhibition might have a beneficial role are discussed. Given the involvement of IL-6 in many pathologies, the diseases that can be improved by IL-6 inhibition will expand. However, the important role of IL-6 in host defense should always be kept in mind in clinical practice.