OA25 Constitutional trisomy 8 mosaicism is associated with a paediatric incomplete Bechet’s-like phenotype

Abstract Introduction/Background Behcet’s disease is a rare paediatric diagnosis and to date there is no single confirmatory gold-standard test or approach. Instead, decisions are clinician-led based on experience, pattern recognition and categorisation according to international criteria. Diagnostic dilemmas arise when patients present at early ages with an incomplete or atypical phenotype. Such cases should prompt clinicians to consider Bechet-like mimics with emphasis of monogenetic and chromosomal causes in younger children. Description/Method A 5-year-old boy with constitutional Trisomy 8 mosaicism was referred to a Bechet’s disease National Centre of Excellence paediatric clinic with cyclical episodes of fever, mouth ulcers, pseudofolliculitis and headaches. During the initial outpatient assessment period (6-12 months) symptoms were reported every 2-3 months and would last for around 1-2 weeks at a time. Physical examination and a photo diary reveal oral ulcers and rashes. He had pre-existing skeletal dysmorphism with severe pectus carinatum, scoliosis and widespread limb contractures secondary to Trisomy 8. Serial blood testing around episodes showed an associated inflammatory response. Although his phenotype was incomplete; with evidence of recurrent autoinflammation a trial of immunosuppression with colchicine was commenced. He displayed a dose-dependent improvement as evidenced by reduction in the frequency and severity of episodes. His Behcet’s-like disease remains well controlled and to date there has been no amyloidosis, ocular, gastrointestinal or cardiovascular complications. Discussion/Results Behcet’s disease is a multisystem chronic vasculitis presenting with widespread mucosal involvement occurring in a relapsing-remitting fashion. Classic manifestations are recurrent sterile aphthous ulcers, genital ulcers, mucosal eye involvement and a positive Pethargy test. It usually presents with all of these classic features by the 3rd or 4th decade of life; children can be affected but usually present with paucity of symptoms not reaching diagnostic criteria. As such, the accumulation of symptoms during a follow-up period may lead to a diagnostic lag of around 3-5 years. The young age of this patient therefore raised clinical suspicion for an alternative diagnosis. The aetiology of Bechet’s disease has elucidated rheumatologists since the first description in 1937. An association with HLA-B51 antigen is well documented but not fully understood. The advent of widely available next-generation genetics provides important clues to its aetiology and helps delineate monogenic and chromosomal mimics. To date 21 genetic loci have been identified through genome-wide association studies and least 11 monogenic and chromosomal mimics been described in the literature. Constitutional Trisomy 8 mosaicism has been shown to be a chromosomal-driven mimic of Behcet disease. It is rare (1-25.000 to 1-50.000 live births) with a 5:1 male predilection; those affected present with a spectrum of abnormal facies, vertebral and limb anomalies including contractures. Interestingly a similar Bechet-like disease is also seen in patients who acquire Trisomy 8 mosaicism in cells affected by myeloid malignancies. Such cases are more numerous and predate those associated with the constitutional form. The final common pathogenesis is thought to be activation of the NF-κB pathway. Reports postulate overexpression of several cytokine genes, production of proinflammatory cytokines and reactive oxygen species. The exact pathogenesis is not fully understood, further research may reveal clues to understanding both Constitutional Trisomy 8 mosaicism and Behcet Disease. Key learning points/Conclusion Learning points: 1. Consider monogenic and chromosomal Behcet Disease mimics in those patients who present at young ages or at any time with atypical or incomplete features. 2. Our patient with Constitutional Trisomy 8 Mosaicism with Behcet-like disease showed a dose-dependent improvement with colchicine.

Key learning points/Conclusion: RP is a rare condition characterized by recurrent inflammation and destruction of cartilaginous structures. RP can present with various clinical findings which can lead to a delay in diagnosis and management The diagnostic criteria includes: McAdam et al.: (1) Recurrent chondritis of both auricles, (2) Nonerosive inflammatory polyarthritis, (3) Chondritis of nasal cartilages, (4) Inflammation of ocular structures, (5) Chondritis of respiratory tract, (6) Cochlear and/or vestibular damage (Requirement-three out of six criteria) Damiani and Levine: (1)  Airway involvement in RP requires prompt corticosteroids/immunosuppression and if severe may lead to stenosis requiring emergency tracheostomy. The treatment should be tailored according to individual patient's organ involvement and complications, although no guidelines exist to date. Awareness of early airway involvement in RP is essential for prompt diagnosis and allows treatment to prevent life-threatening airway collapse. It is essential to examine the auricle, nose and joints in patients presenting with atypical asthma not responding to conventional therapy. Introduction/Background: Behcet's disease is a rare paediatric diagnosis and to date there is no single confirmatory gold-standard test or approach. Instead, decisions are clinician-led based on experience, pattern recognition and categorisation according to international criteria. Diagnostic dilemmas arise when patients present at early ages with an incomplete or atypical phenotype. Such cases should prompt clinicians to consider Bechet-like mimics with emphasis of monogenetic and chromosomal causes in younger children. Description/Method: A 5-year-old boy with constitutional Trisomy 8 mosaicism was referred to a Bechet's disease National Centre of Excellence paediatric clinic with cyclical episodes of fever, mouth ulcers, pseudofolliculitis and headaches. During the initial outpatient assessment period (6-12 months) symptoms were reported every 2-3 months and would last for around 1-2 weeks at a time. Physical examination and a photo diary reveal oral ulcers and rashes. He had pre-existing skeletal dysmorphism with severe pectus carinatum, scoliosis and widespread limb contractures secondary to Trisomy 8. Serial blood testing around episodes showed an associated inflammatory response. Although his phenotype was incomplete; with evidence of recurrent autoinflammation a trial of immunosuppression with colchicine was commenced. He displayed a dose-dependent improvement as evidenced by reduction in the frequency and severity of episodes. His Behcet's-like disease remains well controlled and to date there has been no amyloidosis, ocular, gastrointestinal or cardiovascular complications. Discussion/Results: Behcet's disease is a multisystem chronic vasculitis presenting with widespread mucosal involvement occurring in a relapsing-remitting fashion. Classic manifestations are recurrent sterile aphthous ulcers, genital ulcers, mucosal eye involvement and a positive Pethargy test. It usually presents with all of these classic features by the 3rd or 4th decade of life; children can be affected but usually present with paucity of symptoms not reaching diagnostic criteria. As such, the accumulation of symptoms during a follow-up period may lead to a diagnostic lag of around 3-5 years. The young age of this patient therefore raised clinical suspicion for an alternative diagnosis. The aetiology of Bechet's disease has elucidated rheumatologists since the first description in 1937. An association with HLA-B51 antigen is well documented but not fully understood. The advent of widely available next-generation genetics provides important clues to its aetiology and helps delineate monogenic and chromosomal mimics. To date 21 genetic loci have been identified through genome-wide association studies and least 11 monogenic and chromosomal mimics been described in the literature.
Constitutional Trisomy 8 mosaicism has been shown to be a chromosomal-driven mimic of Behcet disease. It is rare (1-25.000 to 1-50.000 live births) with a 5:1 male predilection; those affected present with a spectrum of abnormal facies, vertebral and limb anomalies including contractures. Interestingly a similar Bechet-like disease is also seen in patients who acquire Trisomy 8 mosaicism in cells affected by myeloid malignancies. Such cases are more numerous and predate those associated with the constitutional form. The final common pathogenesis is thought to be activation of the NF-jB pathway. Reports postulate overexpression of several cytokine genes, production of proinflammatory cytokines and reactive oxygen species. The exact pathogenesis is not fully understood, further research may reveal clues to understanding both Constitutional Trisomy 8 mosaicism and Behcet Disease. Key learning points/Conclusion: Learning points: There is debate about whether WCD is a distinct disease entity or is part of a wider disease spectrum of other disorders. This case highlights the diagnostic conundrum of WCD, its differential diagnosis and subsequent management. It also raises the need to recognise the potential multi-system involvement of WCD. Description/Method: A 3-year-old girl presented with weight loss, rash affecting the lower limbs and joint pains associated with morning stiffness. Past history included speech and language delay, pulmonary stenosis and fibroepithelial hyperplasia of the hard palate. Examination revealed an ejection systolic murmur, hepatosplenomegaly, muscle wasting of left buttock, facial redness, restriction of wrist movements with swelling and right knee swelling. Areas of lipo-hypertrophy were seen overlying both legs, lower back and arm regions. Initial investigations included ESR 30 (mm/hr), CRP 17 (mg/L) with a normal FBC, iron profile, U&E, LFT, rheumatoid factor, CK, immunoglobulins and LDH. Virology and bacteriology screening panels were negative. Autoantibody screen (anti-ds DNA, ENA, ANA, mitochondrial, smooth muscle) was also negative. CXR, XR wrists, ultrasound of abdomen and right knee were normal. Differential diagnosis included panniculitis, malignancy and autoimmune disorders including scleroderma. A biopsy was taken from the right calf, finding evidence of lymphocytic lobular panniculitis. A diagnosis of Weber Christian disease was subsequently made by the paediatric rheumatology team. The patient was commenced on chloroquine, prednisolone and omeprazole. A genetics referral was completed due to concerns with aphasia and presence of a broad face. Microarray revealed a deletion of chromosome 10 (q21.2 -q22.2). Over the next decade, the panniculitis settled on a combination of low dose prednisolone and chloroquine. However, a gradual deterioration in renal function was observed. Renal biopsy found evidence of focal segmental glomerulosclerosis eventually requiring haemodialysis and a subsequent successful renal transplant. Other issues included alopecia (treated with topical steroids), arthritis (managed with corticosteroid injections with limited success) and a large abdominal lipoma (resected by plastic surgery). The patient is now 19 years old with much resolution of the panniculitis and is managed on low dose prednisolone, hydroxychloroquine and omeprazole with mycophenolate, tacrolimus and amlodipine given for renal transplant management. Discussion/Results: Once other disorders were excluded following diagnostic work-up and biopsy, a diagnosis of panniculitis was made.
WCD was the proposed working diagnosis given the clinical features and examination findings. The patient was subsequently successfully managed on immunosuppression including prednisolone, chloroquine which was later replaced by hydroxychloroquine. By monitoring urine dipstick at clinic appointments, microscopic proteinuria and haematuria was detected signifying renal involvement later resulting in a renal transplant. Unusual features of this case include the young age of the patient at diagnosis (3 years old), the severity of renal disease involvement, the rarity of focal segmental glomerulosclerosis at the age of 8 years old and the lack of systemic features (fever) in this presentation of WCD. The identification of a chromosomal deletion is particularly relevant as it raises the question of the significance of this deletion on disease presentation, causation and severity. Expert clinical genetic opinion has suggested that the deletion is highly likely to be significant in relation to the speech delay of our patient and as a possible contributing cause of the patient's panniculitis. Owing to the rarity of this condition and the genetic findings in our patient, the management was based upon a small evidence base of literature and multi-speciality involvement.
Review of the literature on WCD discusses whether WCD is a distinct disease entity or not and argues it should be considered as part of a wider disease spectrum of other related disorders.
Key learning points/Conclusion: This case highlighted the importance of multi-speciality involvement particularly in complex and unusual disorders. Often, these disorders do not follow a textbook description and require an open mind to consider the wider differential diagnosis and subsequent management. Early explanation with the patient's parents about the rarity of the disorder and the complexities of its management was essential. Identifying the most suitable pharmacological agent to manage panniculitis in WCD is based upon a limited evidence base and in our case was achieved with prednisolone, chloroquine and later hydroxychloroquine. Further exploration on suitable treatments for WCD is important along with further discussion on the multi system involvement of this rare disorder.
Abstract citation ID: rkac066.027 OA27 GROWTH OF THE UK AND IRELAND PAEDIATRIC Leeds, United Kingdom, and ldren NHS Foundation Trust Hospital and NIHR BRC, London, United Kingdom Introduction/Background: The Paediatric Rheumatology Clinical Nurse Specialist often has to manage a large caseload of children and young people. Paediatric Rheumatology is an umbrella term of over 80 conditions, most of which are long-term chronic illnesses which can be challenging for families to manage. The Clinical Nurse Specialist is therefore the first point of contact for families who want answers and guidance in caring for their child/young person. The UK and Ireland Paediatric Rheumatology Nurses Group, in turn, provides peer support to these nurses. This abstract will present the growth of this network, particularly over the last two years. Description/Method: Over two decades ago, a UK Paediatric Rheumatology Nurses group was established. Since the group's formation, membership has grown from 20 to over 100 nurses, and has expanded into the Republic of Ireland. All nurses work in paediatrics and most are working solely in Rheumatology as Clinical Nurse Specialists (various titles exist). However, the group also contains nurses who may not solely focus on Rheumatology, but who also manage a number of specialities (one being Rheumatology), and those who have developed their own specialist interest in Rheumatology, often derived from providing clinical support to weekly Rheumatology clinics. The group's Lead Nurse has also encouraged Clinical Research Nurses supporting Paediatric Rheumatology studies to join, as the shared learning is useful to support their clinical practice too. Currently we only have one Paediatric Rheumatology Senior Clinical Research Nurse, but we do have some nurses who manage Paediatric Rheumatology studies as part of their wider clinical roles. Members are located across 37 different centres in the UK and Ireland. Four of these centres have joined in the last month, with nurses hearing about the group and approaching the steering committee about their participation. The centres range from district general hospitals through to specialist regional Children's hospitals. The seniority of our members ranges from band 5 through to band 8b, with three members managing Rheumatology services in a matron capacity. In fifteen of these centres, there is only one Paediatric Rheumatology Nurse within that centre,