Prevalence of anti-endothelial cell antibodies in patients with Sneddon's syndrome

[Sneddon's syndrome]

Sneddon's syndrome is still raising some nosological and etiopathogenic questions. The occurrence of ischemic stroke in young adults especially in the presence of livedo racemosa should suggest the diagnosis and encourage to perform a skin biopsy, which could strengthen the diagnosis. Management begins with prevention of vascular risk factors and treatments based primarily on anti-thrombotic. Large series of studies over several years could provide clarification of the etiopathogenesis of this syndrome and pave the way for the development of diagnostic criteria and new effective therapies in order to prevent progression to irreversible cognitive impairment.

Recurrent macular edema and stroke syndrome in type 1 diabetes mellitus with potent endothelial cell inhibitory autoantibodies

OBJECTIVE

To describe a case of type 1 diabetes mellitus with recurrent macular edema and stroke in association with potent endothelial cell inhibitory autoantibodies.

METHODS

The clinical, radiologic, and biochemical data from the study patient are presented, as is the bioactivity in endothelial cells from the immunoglobulin G fraction of the patient's serum.

RESULTS

A 52-year-old man with a 15-year history of poorly controlled type 1 diabetes mellitus had diabetic autonomic neuropathy, gastroparesis, depression, macular edema, proliferative retinopathy, diabetic nephropathy, refractory hypertension, and transient ischemic attacks that progressed to recurrent strokes despite aspirin therapy. Magnetic resonance imaging of the brain showed multi-focal, bilateral ischemic infarcts consistent with recurrent stroke affecting small vessels. The patient's serum contained endothelial cell inhibitory autoantibodies; the titer doubled during a 2-year period when the patient required repeated focal laser to treat macular edema and experienced transient ischemic attacks. The IgG autoantibodies induced stress fiber formation and apoptosis in endothelial cells and inhibited neurite outgrowth in rat pheochromocytoma PC12 cells.

CONCLUSIONS

Low concentrations of purified autoantibodies (1-2 μg/mL) induce endothelial cell contraction in vitro, suggesting a role for autoantibodies in modulating endothelial cell permeability, which may affect multiple target organs. Potent IgG autoantibodies may be a useful marker (with a possible pathophysiologic role) in an unusual syndrome characterized by poorly controlled diabetes, hypertension, dementia, and recurrent small-vessel stroke.

Cutaneous Vasculitis Update: Neutrophilic Muscular Vessel and Eosinophilic, Granulomatous, and Lymphocytic Vasculitis Syndromes

Most biopsies of cutaneous vasculitis will exhibit a small vessel neutrophilic vasculitis [leukocytoclastic vasculitis (LCV)] that is associated with immune complexes on direct immunofluorescence examination or, less commonly, antineutrophilic cytoplasmic antibodies (ANCA) by indirect immunofluorescence testing. Is in uncommon for skin biopsy to reveal solely a neutrophilic arteritis signifying the presence of cutaneous polyarteritis nodosa or, if accompanied by significant lobular panniculitis, nodular vasculitis/erythema induratum. In other cases, cutaneous vascular damage (fibrinoid necrosis, muscular vessel wall disruption, or endarteritis obliterans) will be mediated by a nonneutrophilic inflammatory infiltrate. Eosinophilic vasculitis can be a primary (idiopathic) process that overlaps with hypereosinophilic syndrome, or it can be a secondary vasculitis associated with connective tissue disease or parasite infestation. Authentic cutaneous granulomatous vasculitis (versus vasculitis with extravascular granulomas) can represent a cutaneous manifestation of giant cell arteritis, an eruption secondary to systemic disease such as Crohn's disease or sarcoidosis, or a localized disorder, often a post-herpes zoster (HZ) phenomenon. Lymphocytic vasculitis is a histologic reaction pattern that correlates with broad clinical differential diagnosis, which includes connective tissue disease - mostly systemic lupus erythematosus (SLE), endothelial infection by Rickettsia and viruses, idiopathic lichenoid dermatoses such as perniosis or ulcerative necrotic Mucha-Habermann disease, and angiocentric cutaneous T-cell lymphomas. Skin biopsy extending into the subcutis, identifying the dominant inflammatory cell and caliber of vessels affected, extravascular histologic clues such as presence of lichenoid dermatitis or panniculitis, and correlation with clinical data allows for accurate diagnosis of these uncommon vasculitic entities.

Pathogenic mechanisms of anti-endothelial cell antibodies (AECA): their prevalence and clinical relevance

Anti‐endothelial cell antibodies (AECA) represent a heterogeneous family of autoantibodies directed against structural endothelial proteins, as well as antigens adhering to endothelial cells. Although AECA immunoassays still show a high‐interlaboratory variability, several findings suggest a pathogenic role of these autoantibodies in diseases characterized by endothelial damage. In this chapter, we analyze the knowledge about AECA prevalence, clinical relevance, and their pathogenic role in autoimmune diseases focusing in particular on systemic lupus erythematosus, antiphospholipid syndrome, systemic sclerosis (SSc), and systemic vasculitis.

Cutaneous Vasculitis Update: Diagnostic Criteria, Classification, Epidemiology, Etiology, Pathogenesis, Evaluation and Prognosis

Vasculitis, inflammation of the vessel wall, can result in mural destruction with hemorrhage, aneurysm formation, and infarction, or intimal-medial hyperplasia and subsequent stenosis leading to tissue ischemia. The skin, in part due to its large vascular bed, exposure to cold temperatures, and frequent presence of stasis, is involved in many distinct as well as un-named vasculitic syndromes that vary from localized and self-limited to generalized and life-threatening with multi-organ disease. To exclude mimics of vasculitis, diagnosis of cutaneous vasculitis requires biopsy confirmation where its acute signs (fibrinoid necrosis), chronic signs (endarteritis obliterans), or past signs (acellular scar of healed arteritis) must be recognized and presence of extravascular findings such as patterned fibrosis or collagenolytic granulomas noted. Although vasculitis can be classified by etiology, many cases have no identifiable cause, and a single etiologic agent can elicit several distinct clinicopathologic expressions of vasculitis. Therefore, the classification of cutaneous vasculitis is best approached morphologically by determining vessel size and principal inflammatory response. These histologic patterns roughly correlate with pathogenic mechanisms that, when coupled with direct immunofluorescent examination, anti-neutrophil cytoplasmic antibody (ANCA) status, and findings from work-up for systemic disease, allow for specific diagnosis, and ultimately, more effective therapy. Herein, we review cutaneous vasculitis focusing on diagnostic criteria, classification, epidemiology, etiology, pathogenesis, and evaluation of the cutaneous vasculitis patient.

The mystery of Sneddon syndrome: relationship with antiphospholipid syndrome and systemic lupus erythematosus

Since its description in 1965, Sneddon syndrome (SNS) is usually characterized by the association of an ischemic cerebrovascular disease and a widespread livedo reticularis. The presence of many other manifestations suggests that it is a systemic syndrome. The prevalence of anti-phospholipid antibodies (aPL) is highly variable, 41% in our experience. Comparison of patients with or without aPL showed that the fishnet of the livedo was clearly larger in aPL-negative patients who nevertheless, did not develop thrombocytopenia. Seizures and clinically audible mitral regurgitation were more frequently observed in aPL-positive patients. These data lead to consider that SNS is not a unique entity. As patients with primary anti-phospholipid syndrome (APS) and SNS did not differ from those with livedo reticularis, ischemic cerebral events and APS within systemic lupus erythematosus (SLE), there is no reason today to exclude patients with SLE. On one hand, SNS might cover a continuum spectrum joining diverse clinico-biological entities ranging from aPL-negative to SLE-related cases, with primary APS-SNS standing amidst. On the other hand, one might speculate that SNS should be regarded as a nearly similar clinical expression of two distinct disorders, i.e. a peculiar form of APS characterized by preferential arteriolar involvement or on the opposite a primary non-aPL related small artery disease mainly involving brain and skin vessels.