Hughes-Stovin syndrome (HSS): current status and future perspectives

Arterial and venous thrombosis in systemic and monogenic vasculitis

Systemic vasculitis, common forms of which include anti-neutrophil cytoplasmic antibody-associated small-vessel vasculitis, large-vessel vasculitis and Behçet syndrome, are frequently complicated by arterial or venous thrombotic events (AVTEs). Newly identified entities such as DADA2 (deficiency of adenosine deaminase 2) and VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome, which are driven by genetic mutations, also exhibit vasculitic features and are associated with a high risk of AVTEs. AVTEs in systemic vasculitis, including monogenic forms of vasculitis, are due to the complex interaction of inflammation and coagulation. New insights into the pathogenetic mechanisms implicate endothelial dysfunction, immune complex deposition and the interplay of pro-inflammatory cytokines with prothrombotic factors, which collectively promote thrombus formation. AVTEs impose a substantial disease burden, complicate diagnosis and negatively affect prognosis by increasing the risk of morbidity and mortality. Early diagnosis and treatment are crucial to prevent lasting damage. Management strategies should target both thrombosis and underlying inflammation. Antithrombotic therapies, including low-dose aspirin, or oral anticoagulants should be used on the basis of individual thrombotic risk assessment. Immunosuppressive therapy is the cornerstone of treatment for arterial and venous thrombosis, particularly in Behçet syndrome, in which vascular inflammation has a crucial role in thrombotic complications.

Beyond the ordinary: TNF-alpha inhibitor as a rescue therapy in relapsing Hughes-Stovin syndrome with intracardiac thrombosis-a case report and literature review

Background

Hughes-Stovin syndrome (HSS) is a rare vasculitis characterized by the association of thrombophlebitis with pulmonary artery aneurysms (PAAs). Because it is rarely reported, there are currently no established diagnostic criteria or standardized treatment guidelines for HSS. While conventional immunosuppressants are generally effective as first-line treatment, relapsing and refractory cases urge the need to investigate alternative therapies, such as TNF-alpha inhibitors. However, with only five cases published in the literature, knowledge of their efficacy in HSS is very limited.

Case summary

A 28-year-old man, with no past medical history, presented with haemoptysis, chest pain, and dyspnoea on exertion. Physical examination found bilateral leg swelling, with no associated lesions. CT angiography showed multiple bilateral PAA, proximal pulmonary artery thrombosis (PAT), and deep venous thrombosis (DVT) in the superior mesenteric vein and spleno-mesaraic confluence. Echocardiography was performed, identifying right intracardiac thrombosis (ICT). Initial management included high-dose corticosteroids and monthly cyclophosphamide cycles, followed by maintenance treatment with oral azathioprine. Eighteen months later, the patient presented with haemoptysis revealing a relapse of ICT and two new PAA. Infliximab was initiated, allowing complete and sustained remission after one year of follow-up.

Discussion

We report the challenging case of an HSS patient presenting with multiple PAA, proximal PAT, right ICT, and extended abdominal DVT. The positive response of our patient to infliximab, following a relapse under conventional immunosuppressants, supports the efficacy of TNF-alpha inhibitors as second-line treatment in relapsing/refractory HSS.

[Hughes-Stovin syndrome: a life-threatening manifestation of Behçet's syndrome]

Hughes-Stovin syndrome (HSS) is a systemic inflammatory condition of unknown origin that is considered to be part of the Behçet's syndrome (BS) spectrum. Recurrent venous thrombosis and superficial thrombophlebitis in combination with bilateral pulmonary artery aneurysms (PAA) represent the hallmark of HSS. The diagnostic evaluation includes computed tomography pulmonary angiography to detect signs of pulmonary vasculitis. The management of HSS is based on the European Alliance of Associations for Rheumatology (EULAR) recommendations for BS and mainly comprises immunosuppressive therapy with glucocorticoids and cyclophosphamide. In addition to drug therapy, PAA should be evaluated for interventional treatment. Spontaneous PAA rupture due to fragile vessel architecture can occur even in cases of remission and/or PAA regression.

Diagnostic Approach to Recurrent Intracardiac Masses That Present With Systemic Symptoms

Cardiac masses are difficult to diagnose in the pediatric population, especially in the setting of systemic symptoms. Although multiple imaging modalities are available to characterize cardiac masses, it is important to consider a different diagnostic approach in the setting of recurrent cardiac masses and nonspecific systemic symptoms. We present a case involving a previously healthy adolescent with multiple hospitalizations because of persistent fevers, cachexia, and recurrent cardiac masses. Echocardiography and cardiac computed tomography imaging suggested endocarditis, but the patient failed to respond to multiple intravenous antibiotic treatments. He developed recurrent cardiac masses in the right atrium and right ventricle that were debulked and biopsied. The biopsy did not yield a conclusive diagnosis. The patient returned to the hospital with hemoptysis and large pulmonary pseudoaneurysms that had to be occluded during cardiac catheterization. Given his constellation of symptoms and improvement with steroids during surgical procedures, he was ultimately diagnosed with a variant of Behcet's disease known as Hughes-Stovin syndrome. His symptoms resolved completely with steroids and immunosuppression therapy. Our report reveals the limitations of the standard diagnostic approach toward cardiac masses and the importance of considering response to treatment as a clue to the etiology of an unusual cardiac mass.

Frail Silk: Is the Hughes-Stovin Syndrome a Behçet Syndrome Subtype with Aneurysm-Involved Gene Variants?

Hughes-Stovin syndrome is a rare disease characterized by thrombophlebitis and multiple pulmonary and/or bronchial aneurysms. The etiology and pathogenesis of HSS are incompletely known. The current consensus is that vasculitis underlies the pathogenic process, and pulmonary thrombosis follows arterial wall inflammation. As such, Hughes-Stovin syndrome may belong to the vascular cluster with lung involvement of Behçet syndrome, although oral aphtae, arthritis, and uveitis are rarely found. Behçet syndrome is a multifactorial polygenic disease with genetic, epigenetic, environmental, and mostly immunological contributors. The different Behçet syndrome phenotypes are presumably based upon different genetic determinants involving more than one pathogenic pathway. Hughes-Stovin syndrome may have common pathways with fibromuscular dysplasias and other diseases evolving with vascular aneurysms. We describe a Hughes-Stovin syndrome case fulfilling the Behçet syndrome criteria. A MYLK variant of unknown significance was detected, along with other heterozygous mutations in genes that may impact angiogenesis pathways. We discuss the possible involvement of these genetic findings, as well as other potential common determinants of Behçet/Hughes-Stovin syndrome and aneurysms in vascular Behçet syndrome. Recent advances in diagnostic techniques, including genetic testing, could help diagnose a specific Behçet syndrome subtype and other associated conditions to personalize the disease management.

Hughes-Stovin Syndrome: An Experience of Management of 3 Cases From a Tertiary Health Care Centre

Three young males with Hugh-Stovin's syndrome presented with cough, haemoptysis, fever, raised inflammatory markers, and pulmonary artery aneurysm. Only one had recurrent oral ulcers suggestive of Behcet's disease, and none were HLA B51 positive. All responded well to immunosuppression but eventually needed either an endovascular procedure or surgery.

Paediatric Behçet's Disease: A Comprehensive Review with an Emphasis on Monogenic Mimics

Behçet's disease (BD) is a polygenic condition with a complex immunopathogenetic background and challenging diagnostic and therapeutic concepts. Advances in genomic medicine have provided intriguing insights into disease pathogenesis over the last decade, especially into monogenic mimics of BD. Although a rare condition, paediatric BD should be considered an important differential diagnosis, especially in cases with similar phenotypes. Emerging reports of monogenic mimics have indicated the importance of genetic testing, particularly for those with early-onset, atypical features and familial aggregation. Treatment options ought to be evaluated in a multidisciplinary setting, given the complexity and diverse organ involvement. Owing to the rarity of the condition, there is a paucity of paediatric trials; thus, international collaboration is warranted to provide consensus recommendations for the management of children and young people. Herein, we summarise the current knowledge of the clinical presentation, immunopathogenetic associations and disease mechanisms in patients with paediatric BD and BD-related phenotypes, with particular emphasis on recently identified monogenic mimics.