Childhood- versus Adult-Onset Polyarteritis Nodosa Results from the French Vasculitis Study Group Registry

Adenosine Deaminase 2 Deficiency Caused by Biallele Variants Including Splicing Variant: The First Case in Korea

Deficiency of adenosine deaminase 2 (DADA2) is an autoinflammatory disease caused by pathogenic variants of the ADA2 gene and has similar clinical features to polyarteritis nodosa (PAN). We, herein, report a case of DADA2 in Korea that was diagnosed in a patient with childhood-onset PAN. The patient had a truncal ataxia and facial palsy caused by thalamic infarction at 34 months of age. Livedo reticularis with Raynaud phenomenon and abdominal pain with fever were followed. Radiologic examination showed multiple infarctions in brain and kidney. She was diagnosed with PAN using skin biopsy and angiography. She had severe hemorrhagic strokes despite medical treatments. Her disease activity was controlled after adding a tumor necrosis factor-α inhibitor. Molecular analysis revealed compound heterozygous pathogenic variants of ADA2 gene. This is the first case of DADA2 in Korea. Genetic analysis for ADA2 gene should be considered in patients with childhood-onset PAN.

Mycophenolate mofetil in the treatment of childhood systemic polyarteritis nodosa

Polyarteritis nodosa (PAN) is a medium vessel vasculitis with necrotising vascular changes along with multisystemic involvement. Due to variable initial presentations, diagnosis of systemic PAN in children requires a comprehensive work up. In addition, systemic PAN needs an aggressive therapy. Mycophenolate mofetil is an emerging newer alternative for the treatment of PAN. We report a case of childhood systemic PAN who initially presented with subtle signs like reduced sensation over lateral foot, non-deforming arthritis and multiform rashes. After comprehensive aetiological work up, nerve biopsy and supporting evidence clinched the diagnosis. Vasculitis in children presenting with benign subtle signs is sometimes a diagnostic challenge to clinicians. Our case highlights the importance of lateral thinking while dealing with non-specific multisystemic signs. Evidence of successful treatment of PAN with mycophenolate mofetil is gradually being built up. It is also described to result lower relapse and increased treatment free survival rate.

[Primary vasculitides in childhood and adulthood]

Primary systemic vasculitides can be observed at any age. Some vasculitides occur preferentially in childhood, such as Kawasaki syndrome or immunoglobulin A (IgA) vasculitis, whereas others, such as giant cell arteritis, occur beyond the age of 50 years. Vasculitides occurring in childhood or adolescence and adulthood may have different phenotypes, different disease courses and outcomes depending on the age of manifestation. For example, those with Takayasu arteritis beginning in adolescence have different vascular involvement, a higher degree of systemic inflammation and a more aggressive course of disease than those with adult-onset disease. In contrast, IgA vasculitis is more severe in adults than in children. The causes for the age predilections and different age-dependent disease manifestations have not yet been clarified. The therapeutic principles are similar for vasculitides occurring in children or adolescents and adults. The first international evidence-based treatment recommendations are now available for juvenile vasculitides, although the evidence for certain forms of treatment is still very limited. The treatment of adult vasculitides can be guided by numerous national and international guidelines and recommendations. Many vasculitides carry a high risk of morbidity and mortality and the timely detection and treatment are therefore necessary. In this article, similarities and differences in the clinical presentations, treatment, courses and prognosis of vasculitides in children or adolescents and adults are discussed.

Polyarteritis Nodosa: State of the art

Polyarteritis nodosa (PAN) is a systemic necrotizing vasculitis that preferentially affects medium-sized vessels. The idiopathic form has become rare. Its treatment relies on corticosteroid therapy and is combined with cyclophosphamide infusions for severe forms. Secondary PANs were mainly associated with hepatitis B virus infection; they were treated with plasma exchange and antivirals in combination with short-term corticosteroid therapy. Other secondary forms of PAN are now becoming more common, such as those due to blood disorders. More recently, a monogenic form linked to adenosine deaminase-2 mutations has been identified. It requires treatment with TNF inhibitors to decrease the occurrence of ischemic central nervous system complications, which make it serious. Once remission is obtained, relapses are typically rare during PAN and affect 28% of idiopathic PANs, within an average of 26 months from the diagnosis. The prognosis has improved considerably, with 5- and 10-year survival rates of 83% and 74%.

Clinical Characteristics and Outcomes of Mexican Patients With Polyarteritis Nodosa: A Single-Center Study Over 40 Years

METHODS

We conducted a medical records review study (1975-2018) that included patients with childhood- and adult-onset PAN. Demographics, organ involvement, phenotype, treatment, and outcomes were assessed and compared against previously published cohorts.

RESULTS

Thirty-one patients were included, 20 (64.5%) female, with a median age at diagnosis of 28 years (interquartile range [IQR], 16-42). Seven (23%) were classified as cutaneous; 23 (74%), systemic; and 1 (3%), progressive systemic phenotype. Eleven patients (35%) had childhood-onset PAN. Most common manifestations were musculoskeletal (71%), cutaneous (68%), constitutional (61%), peripheral neuropathy (39%), and gastrointestinal (29%). The median Birmingham Vasculitis Activity Score and Five-Factor Score at diagnosis were 9 (IQR, 4-13) and 1 (IQR, 0-1), respectively. Most patients were treated with glucocorticoids (94%). Twenty-four (80%) achieved complete and 6 (20%) partial remission at a median follow-up time of 30 months (8-192 months). The median Vasculitis Damage Index at last follow-up was 1 (IQR, 0-1). Nineteen (66%) experienced relapses. Patients with childhood-onset PAN more frequently had central nervous system and gastrointestinal involvement (36% vs 5%, p = 0.04 and 64% vs 10%, p = 0.003, respectively), microaneurysms (100% vs 38%, p = 0.02), and lower levels of C-reactive protein (0.3 vs 15.4 mg/dL, p = 0.03), compared with adult-onset PAN patients.

CONCLUSIONS

Our cohort of PAN patients showed predominantly a systemic phenotype. Outcomes were generally good, with most patients achieving complete remission. Childhood-onset differed from adult-onset PAN in terms of clinical and serological characteristics, whereas clinical manifestations and outcomes may be different than the ones reported in other cohorts.

Systematic review of childhood-onset polyarteritis nodosa and DADA2

BACKGROUND

Diagnosis of childhood polyarteritis nodosa (PAN) has become challenging after the definition of deficiency of adenosine deaminase 2 (DADA2). We aimed to define the differential features of pediatric PAN and DADA2 patients in our center and in the literature.

METHODS

The charts of pediatric PAN and DADA2 patients followed at the Pediatric Rheumatology Unit of Hacettepe University between 2010-2020 were analyzed. A systematic literature review was conducted for articles regarding pediatric PAN or DADA2.

RESULTS

Thirty-four pediatric PAN and 18 pediatric DADA2 patients were included. The age at onset was younger, parental consanguinity, livedo reticularis, neurologic involvement (especially strokes), lymphopenia, and hypogammaglobulinemia were more frequent, while thrombocytosis and panniculitis were less frequent in DADA2 patients. The primary treatment was anti-tumor necrosis factor (anti-TNF) in DADA2. For induction treatment, all systemic PAN patients received corticosteroids, and cyclophosphamide (n=11) or mycophenolate mofetil (MMF) (n = 3). Cyclophosphamide was replaced with MMF in nine once remission was confirmed with PVAS. In the literature, 28 articles describing 613 pediatric PAN patients and 26 articles describing 207 pediatric DADA2 patients were identified. Neurologic, gastrointestinal, and cardiac involvements were more frequent in DADA2, while constitutional symptoms and testis involvement were more common in PAN.

CONCLUSION

In a child with PAN-like phenotype, DADA2 should be considered in the presence of young age at disease onset, parental consanguinity, strokes, lymphopenia, and lack of thrombocytosis during active disease. Anti-TNF treatment is indicated for vasculitic DADA2. Cyclophosphamide could be switched to MMF when remission is confirmed with PVAS in severe PAN.

Biologic drugs in the treatment of polyarteritis nodosa and deficit of adenosine deaminase 2: A narrative review

Polyarteritis nodosa (PAN) is a medium vessels vasculitis variously involving different organs and systems, sometimes with an aggressive course, leading to death or disability in a significant number of cases. First-line treatment usually relies on steroids and classical immunosuppressants, but a growing number of case reports and small case series shows the potential role of biologic drugs, mostly anti-tumor necrosis factor (TNF)-α agents, in inducing and maintaining remission in patients affected by PAN. Similarly, the recently described autoinflammatory disease named deficit of adenosine deaminase 2 (DADA2), considered by several experts as a more precocious and aggressive variant of PAN, seems to respond to a prompt treatment with TNF-α inhibitors. The aim of this review is to collect all existing evidences about the use of biologic drugs in PAN and DADA2. Fifty-one articles published during the last 15 years were retrieved, including 58 and 76 patients affected by PAN and DADA2, respectively, and treated with biologic drugs. The majority of subjects was treated with TNF-α inhibitors, whose effectiveness was reported in the treatment of such difficult-to-manage diseases, particularly in DADA2. Among the other biologic drugs, Tocilizumab was successfully employed in some subjects affected by PAN who did not respond to TNF-α inhibitors, while Rituximab did not give substantial benefits neither in PAN nor in DADA2. Only few data exist about the role of Janus-kinase inhibitors and anti-IL1 agents. This study provides the first comprehensive assessment of biologic agents in both PAN and DADA2, with encouraging results especially in the context of TNF-α inhibitors. Nevertheless, due to the lack of prospective, randomized, case control studies, further efforts should be made in order to fully elucidate the role of these drugs in such rare and life-threatening conditions.

Cutaneous polyarteritis nodosa in a 7-year-old boy: difficulties in diagnosis

Vasculitides are a diverse group of diseases. The potential diversity of their clinical symptoms requires the exclusion of other systemic connective tissue diseases, infectious diseases or malignancies. Due to similar clinical manifestations, comprehensive differential diagnosis is needed. This paper presents the case of a boy in whom polyarteritis nodosa, early stage of Behçet's disease or autoimmune/autoinflammatory syndrome induced by adjuvants was suspected following initial diagnostics. He was ultimately diagnosed with cutaneous polyarteritis nodosa.

Childhood- Versus Adult-Onset Primary Vasculitides: Are They Part of the Same Clinical Spectrum?

PURPOSE OF THE REVIEW

Most of the primary vasculitis in children and adults has different clinical manifestations for the same disease, which suggests that they might not be part of the same clinical spectrum and requires a different approach in order to reduce the morbidity and mortality of these patients. In this work, we review the most recent literature and the most important studies that describe and compare adult and children primary vasculitides pathogenesis, clinical presentation, and treatment approach. Accordingly, we discuss recent research involving clinical trials, comparison studies, and pathogeny for these vasculitides.

RECENT FINDINGS

Clinical manifestations in the different primary vasculitis change in predominance from adults to children. There is a female sex predominance for the ANCA vasculitides in children compared with adults, but the same treatment works in most cases for both groups. Identifying the diverse clinical spectrum in both adults and children primary vasculitides will reduce the need to extrapolate the diagnostic criteria from one group to another and individualize it, which will allow the clinician to establish a better approach.