Blau syndrome: Lessons learned in a tertiary care centre at Chandigarh, North India

Blau Syndrome: Challenging Molecular Genetic Diagnostics of Autoinflammatory Disease

The aim of this study was to describe the clinical and molecular genetic findings in seven individuals from three unrelated families with Blau syndrome. A complex ophthalmic and general health examination including diagnostic imaging was performed. The NOD2 mutational hot spot located in exon 4 was Sanger sequenced in all three probands. Two individuals also underwent autoinflammatory disorder gene panel screening, and in one subject, exome sequencing was performed. Blau syndrome presenting as uveitis, skin rush or arthritis was diagnosed in four cases from three families. In two individuals from one family, only camptodactyly was noted, while another member had camptodactyly in combination with non-active uveitis and angioid streaks. One proband developed two attacks of meningoencephalitis attributed to presumed neurosarcoidosis, which is a rare finding in Blau syndrome. The probands from families 1 and 2 carried pathogenic variants in NOD2 (NM_022162.3): c.1001G>A p.(Arg334Gln) and c.1000C>T p.(Arg334Trp), respectively. In family 3, two variants of unknown significance in a heterozygous state were found: c.1412G>T p.(Arg471Leu) in NOD2 and c.928C>T p.(Arg310*) in NLRC4 (NM_001199139.1). In conclusion, Blau syndrome is a phenotypically highly variable, and there is a need to raise awareness about all clinical manifestations, including neurosarcoidosis. Variants of unknown significance pose a significant challenge regarding their contribution to etiopathogenesis of autoinflammatory diseases.

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.

Update on ocular manifestations of the main monogenic and polygenic autoinflammatory diseases

Autoinflammatory diseases include disorders with a genetic cause and also complex syndromes associated to polygenic or multifactorial factors. Eye involvement is present in many of them, with different extent and severity. The present review covers ophthalmological lesions in the most prevalent monogenic autoinflammatory diseases, including FMF (familial Mediterranean fever), TRAPS (TNF receptor-associated periodic syndrome), CAPS (cryopyrin-associated periodic syndromes), Blau syndrome, DADA2 (deficiency of adenosine deaminase 2), DITRA (deficiency of the interleukin-36 receptor antagonist), other monogenic disorders, including several ubiquitinopathies, interferonopathies, and the recently described ROSAH (retinal dystrophy, optic nerve edema, splenomegaly, anhidrosis, and headache) syndrome, and VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome. Among polygenic autoinflammatory diseases, ocular manifestations have been reviewed in Behçet's disease, PFAPA (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) syndrome, Still's disease and autoinflammatory bone diseases, which encompass CRMO (chronic recurrent multifocal osteomyelitis) and SAPHO (synovitis, acne, pustulosis, hyperostosis and osteitis) syndrome.

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.

Distinct NOD2 mutations reported in three families with Blau syndrome (BS) from a single center in India - Case series and review of literature

OBJECTIVE

Blau syndrome (BS), considered a rare pediatric autoinflammatory disease, is characterised by a triad of granulomatous arthritis, dermatitis and uveitis. Here we present a tale of three families visited in our outpatient department in the last two years (2020-2022) where more than one member was affected with either skin, ophthalmological and joint involvement with either biopsy-proven granuloma or genetic mutation at NOD2 gene suggesting the diagnosis of BS.

CASE SERIES

The first family had three affected members where the mother and her two children had skin changes, polyarthritis and a pathogenic mutation in NOD2 gene (exon 4, c.1000C > T, p.Arg334Trp) suggesting BS. The second family had two affected members where both mother and her son had uveitis, skin changes with NOD2 mutation at exon 4 with c.1147G > A (p Glu 383 Lys) variant. The son also had polyarthritis and his skin biopsy was suggestive of granulomatous inflammation. In the third family with two affected members, we found a mutation in NOD2 on exon 4 (c 1324C > T, p.Lys 442 Phe) which was described as pathogenic with only one report published till date.

CONCLUSION

These three cases presented to us within the last two years and led to a diagnosis of BS in three other family members with discrete mutations (commonest to rarest) on the NOD2 gene in the three families.

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.