A novel mutation in early-onset sarcoidosis/Blau syndrome: an association with Propionibacterium acnes

Pulmonary granulomas confirmed in Blau syndrome using TBLC specimens: Case report

Blau syndrome (BS), is an autoinflammatory granulomatosis disease characterized by a distinct triad of skin, joint, and eye disorders similar to those of sarcoidosis, but the lung involvement frequently observed in sarcoidosis are rare. Granulomas from patients with BS displayed a distinct morphology indicating an exuberant chronic inflammatory response. Patients with BS may have granulomatous lung lesions, which require early diagnosis. To determine whether therapeutic intervention is needed for lung lesions, examining transbronchial lung cryobiopsy specimens and accumulating cases of BS with lung involvement could be contributed to improving BS management in the future.

Intravitreal Fluocinolone Acetonide 0.19 mg Implant in a Patient with Resistant Blau Syndrome: A Case Report

Introduction

Blau syndrome is a progressive disease with an unknown etiology and pathogenesis. It can cause severe damage, especially in the eye with severe involvement.

Case Presentation

A six-year-old female was referred to us complaining about blurry vision and floaters in both eyes for 1 year. She had been diagnosed with Blau syndrome and Blau syndrome-associated anterior uveitis. Her best-corrected visual acuity in the right and left eyes was 20/70 and 20/80, respectively. Slit-lamp exam revealed faint bilateral band keratopathy along with 1+ anterior chamber cells and posterior synechia 360° in both eyes. During dilated fundoscopy, 2+ haze in the media was observed, along with swollen and hyperemic disc OU. Based on changes in optical coherence tomography, fluorescein angiography, and indocyanine green angiography, she was diagnosed with panuveitis and retinal vasculitis. Given her complicated history, we decided to proceed with an intravitreal fluocinolone acetonide 0.19 mg implant implantation in both eyes. During the 1-month follow-up visit, vitreous haze, retinal vasculitis, and active choroiditis were resolved. At 6-month follow-up visit, no changes were observed compared to the 1-month follow-up visit.

Conclusion

In cases of Blau syndrome that display resistance to systemic immunomodulatory therapies, the inclusion of local treatments, such as the intravitreal fluocinolone acetonide 0.19 mg implant, should be considered as an adjunctive therapeutic option.

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.

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.

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.

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.

Updates in cutaneous manifestations of systemic vasculitis

PURPOSE OF REVIEW

The main purpose of this review is to present newly reported cutaneous manifestations of systemic vasculitis, updates in investigations to verify systemic involvement in cases with cutaneous vasculitis and new therapeutic guidelines. The spectrum of COVID-19-related vasculitis is also covered.

RECENT FINDINGS

Only a few reports highlighted new cutaneous presentations or associations with some systemic vasculitic entities. For example, the association of inflammatory disorders with Takayasu arteritis, the importance of considering Kawasaki disease in febrile children with erythema nodosum, the development of necrotic ulcers on fingers and toes in Behçet's disease and the possible presence of polyarteritis nodosa-like pathological features in vulvar ulcers of Behçet's disease. New attempts to classify cutaneous manifestations of giant cell arteritis (GCA) and antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and the diagnostic investigations for cutaneous vasculitis cases to verify systemic involvement are discussed. Treatment of systemic vasculitis with cutaneous vasculitis should be tailored according to disease status. A plethora of reports in the past 2 years focused on the broad spectrum of COVID-19 vasculitic manifestations.

SUMMARY

Although newly reported cutaneous manifestations of systemic vasculitis are relatively uncommon, the plethora of reports in the past 2 years on COVID-19 vasculitis necessitates the expansion of the classification of vasculitis associated with probable cause to include severe acute respiratory syndrome coronavirus-2 (SARS-Cov-2) vasculitis.