Systemic granulomatous arteritis associated with Epstein-Barr virus infection

Herpesvirus Infection of Endothelial Cells as a Systemic Pathological Axis in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

Understanding the pathophysiology of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is critical for advancing treatment options. This review explores the novel hypothesis that a herpesvirus infection of endothelial cells (ECs) may underlie ME/CFS symptomatology. We review evidence linking herpesviruses to persistent EC infection and the implications for endothelial dysfunction, encompassing blood flow regulation, coagulation, and cognitive impairment-symptoms consistent with ME/CFS and Long COVID. This paper provides a synthesis of current research on herpesvirus latency and reactivation, detailing the impact on ECs and subsequent systemic complications, including latent modulation and long-term maladaptation. We suggest that the chronicity of ME/CFS symptoms and the multisystemic nature of the disease may be partly attributable to herpesvirus-induced endothelial maladaptation. Our conclusions underscore the necessity for further investigation into the prevalence and load of herpesvirus infection within the ECs of ME/CFS patients. This review offers conceptual advances by proposing an endothelial infection model as a systemic mechanism contributing to ME/CFS, steering future research toward potentially unexplored avenues in understanding and treating this complex syndrome.

Environmental factors influencing the risk of ANCA-associated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of diseases characterized by inflammation and destruction of small and medium-sized blood vessels. Clinical disease phenotypes include microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA). The incidence of AAV has been on the rise in recent years with advances in ANCA testing. The etiology and pathogenesis of AAV are multifactorial and influenced by both genetic and environmental factors, as well as innate and adaptive immune system responses. Multiple case reports have shown that sustained exposure to silica in an occupational environment resulted in a significantly increased risk of ANCA positivity. A meta-analysis involving six case-control studies showed that silica exposure was positively associated with AAV incidence. Additionally, exposure to air pollutants, such as carbon monoxide (CO), is a risk factor for AAV. AAV has seasonal trends. Studies have shown that various environmental factors stimulate the body to activate neutrophils and expose their own antigens, resulting in the release of proteases and neutrophil extracellular traps, which damage vascular endothelial cells. Additionally, the activation of complement replacement pathways may exacerbate vascular inflammation. However, the role of environmental factors in the etiology of AAV remains unclear and has received little attention. In this review, we summarized the recent literature on the study of environmental factors, such as seasons, air pollution, latitude, silica, and microbial infection, in AAV with the aim of exploring the relationship between environmental factors and AAV and possible mechanisms of action to provide a scientific basis for the prevention and treatment of AAV.

Innate Immune Modulation Induced by EBV Lytic Infection Promotes Endothelial Cell Inflammation and Vascular Injury in Scleroderma

Microvascular injury is considered an initial event in the pathogenesis of scleroderma and endothelial cells are suspected of being the target of the autoimmune process seen in the disease. EBV has long been proposed as a trigger for autoimmune diseases, including scleroderma. Nevertheless, its contribution to the pathogenic process remains poorly understood. In this study, we report that EBV lytic antigens are detected in scleroderma dermal vessels, suggesting that endothelial cells might represent a target for EBV infection in scleroderma skin. We show that EBV DNA load is remarkably increased in peripheral blood, plasma and circulating monocytes from scleroderma patients compared to healthy EBV carriers, and that monocytes represent the prominent subsets of EBV-infected cells in scleroderma. Given that monocytes have the capacity to adhere to the endothelium, we then investigated whether monocyte-associated EBV could infect primary human endothelial cells. We demonstrated that endothelial cells are infectable by EBV, using human monocytes bound to recombinant EBV as a shuttle, even though cell-free virus failed to infect them. We show that EBV induces activation of TLR9 innate immune response and markers of vascular injury in infected endothelial cells and that up-regulation is associated with the expression of EBV lytic genes in infected cells. EBV innate immune modulation suggests a novel mechanism mediating inflammation, by which EBV triggers endothelial cell and vascular injury in scleroderma. In addition, our data point to up-regulation of EBV DNA loads as potential biomarker in developing vasculopathy in scleroderma. These findings provide the framework for the development of novel therapeutic interventions to shift the scleroderma treatment paradigm towards antiviral therapies.

Epstein-Barr virus-related cutaneous necrotizing vasculitis in a girl heterozygous for factor V Leiden

Background

Necrotizing vasculitides are basically characterized by vessel wall neutrophil infiltration and necrosis and they can occur as a primary process or secondary to an underlying disease. Although Henoch-Schönlein purpura (HSp) is the more frequent primary vasculitis in childhood, sometimes it has to be distinguished from other secondary vasculitides induced by infections, drugs, vaccines, or immune-mediated disorders.

Main observations

We report a case of a 14-year-old girl with cutaneous necrotizing vasculitis, appearing in the course of acute Epstein-Barr virus infection. Physical examination revealed highly aching erythematous-purple lesions with reticular edges localized on the back of feet. Pain was non-responsive to ibuprofen and required administration of tapentadol and pregabalin. The patient was also heterozygous for factor V Leiden that might have contributed to the development of cutaneous painful lesions.

Conclusions

To our knowledge this is the first documented pediatric case of necrotizing vasculitis associated with acute EBV infection in a girl heterozygous for factor V Leiden. In this patient the severity of skin manifestations might have been influenced by the concomitant factor V Leiden, which gave rise to hypercoagulability and occlusive vasculopathy with markedly severe pain, a symptom rather infrequent in other childhood vasculitides.

Lymphocytic Arteritis in Epstein-Barr Virus Vulvar Ulceration (Lipschütz Disease): A Report of 7 Cases

Epstein-Barr virus (EBV) infection can rarely present as painful genital ulcers, mostly in young female adolescents. Typically diagnosed by clinical findings, EBV vulvar ulceration (EBVVU) is rarely biopsied. Herein, the authors report the histopathology in 8 biopsies from 7 EBVVU patients, all serologically confirmed for acute (4/7) or reactivated-chronic (3/7) EBV infection. The 7 women all presented with 1 or more painful, punched-out vulvar ulcers. Only patients with acute EBV infection showed other clinical findings: fever and/or atypical lymphocytosis affected 75% (3/4); lymphadenopathy in 50%; and malaise/fatigue, dysuria and/or hepatomegaly in 25%. All reactivated-chronic EBVVU had a solitary ulcer, and 2 had history of a similar episode of vulvar ulceration (aphthosis). Histopathologically, lymphocytic arteritis was identified in 88% (7/8); a submucosal scar was found in the eighth specimen. Other histopathologies included venulitis (62%), endarteritis obliterans (38%), thrombosis (25%), neutrophilic sebaceous adenitis (25%), and mucosal lymphoid hyperplasia (12%). Dense angiocentric CD3 CD4 T-cell lymphocyte-predominant infiltrates were found, regionally or diffusely. In 2 specimens, neutrophils compromised half of the infiltrate. Minor components of CD8, CD20, and CD30 lymphocytes, CD123 plasmacytoid monocytes, CD68 macrophages, and plasma cells were present. Small-vessel endothelium and smooth muscle adjacent to the ulcers faintly expressed cytoplasmic EBV latent membrane protein-1 (LMP1). In situ hybridization for early EBV mRNA (EBER) identified rare solitary or scattered clustered positive lymphocytes in 38%. Polymerase chain reaction for EBV DNA was positive in one EBER positive biopsy. EBV infection has been documented in muscular vessel vasculitis. Based on the aforementioned, EBVVU appears to be the consequence of localized lymphocytic arteritis.

Vasculitis related to viral and other microbial agents

Vasculitis due to infection may occur as a consequence of the inflammation of vessel walls due to direct or contiguous infection, type II or immune complex-mediated reaction, cell-mediated hypersensitivity, or inflammation due to immune dysregulation triggered by bacterial toxin and/or superantigen production. As immunosuppressive therapy administered in the absence of antimicrobial therapy may increase morbidity and fail to effect the resolution of infection-associated vascular inflammation, it is important to consider infectious entities as potential inciting factors in vasculitis syndromes. The causality between infection and vasculitis has been established in hepatitis B-associated polyarteritis nodosa (HBV-PAN) and hepatitis C-associated (cryoglobulinemic) vasculitis (HCV-CV). The review summarizes the recent literature on the pathophysiological mechanisms and the approaches to the management of HBV-PAN and HCV-CV. Roles of other viral and microbial infections, which either manifest as vasculitic syndromes or are implicated in the pathogenesis of primary vasculitides, are also discussed.

Anti-neutrophil cytoplasmic antibody-associated vasculitis associated with infectious mononucleosis due to primary Epstein-Barr virus infection: report of three cases

Although the aetiology of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis remains unclear, it is generally believed that environmental factors such as infections contribute to its development of ANCA-associated vasculitis. Prior Epstein–Barr virus (EBV) infection is reported to be a trigger of systemic vasculitis. We herein report three cases of ANCA-associated vasculitis presenting with infectious mononucleosis due to primary EBV infection. The causal link between the two pathologies could not be proved, but primary EBV infection may play a role in the initiation or exacerbation of ANCA-associated vasculitis. Future studies are necessary to determine the interaction between these diseases conditions.

The role of infectious agents in the pathogenesis of vasculitis

Numerous human studies and animal models have implicated various infectious agents in the pathogenesis of vasculitis in susceptible hosts. However, the link between infection and vasculitis is very complex and only incompletely understood. In fact, different agents can induce the same type of vasculitis, as the case of leukocytoclastic vasculitis exemplifies. Conversely, the same agent can give rise to a panoply of host responses ranging from a clinically silent infection or localized organ involvement to devastating, widespread vasculitis.

[Systemic granulomatosis of infectious origin]

PURPOSE

Granulomatous diseases are defined by specific histological features, following the local recruitment of macrophages and lymphocytes. Many infections can lead to the development of granuloma.

CURRENT KNOWLEDGE AND KEY POINTS

Microorganisms responsible for granuloma include mainly mycobacteria, many viral and fungal species, as well as schistosoma in endemic areas. Nevertheless, almost all microorganisms can lead to granuloma, especially if their clearance needs macrophages pathway. New immunosuppressive drugs such as tumor necrosis factor antagonists are associated with a high risk of infectious granulomatous complications. All patients with granuloma must be carefully screened to find a potential underlying infection, since an immunosuppressive therapy could be otherwise considered. We here review the general diagnostic process with a specific glance to the main organs.

FUTURE PROSPECTS AND PROJECTS

Without clinical or epidemiological clue, diagnosis can be very tedious. New molecular tools now assist classical microbiological and histological techniques. Their specificity and sensitivity have recently been better characterized, and their use will probably increase in the near future for the diagnosis of infectious granuloma. They may also lead to discover new infectious aetiologies of granulomatous diseases formerly considered as idiopathic. We describe here the main microorganisms that can be responsible for granuloma, with a specific focus on the use of new diagnostic tools.

Systemic granulomatous necrotizing vasculitis in a MPO-ANCA-positive patient

We present a case of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis that demonstrated a systemic granulomatous lesion at autopsy. The patient initially showed anorexia, general malaise and anemia. Colon fiber was examined to detect the bleeding site, which revealed ischemic mucosal damage associated with venous fibrin thrombus. Because a high titer of MPO-ANCA was found, ANCA-associated vasculitis was suspected and the patient was started on steroid pulse therapy. However, anemia, renal failure and respiratory failure worsened and the patient died of sudden cardiac failure 2 days after the start of the therapy. An autopsy revealed systemic arteritis in multiple organs including the kidneys, liver, spleen, gastrointestinal system and genital organs that indicated fibrinoid necrosis accompanied by granulomatous reaction with multinucleated giant cells; the granulomatous reaction further extended along the splenic capsule. Glomerulonephritis and diffuse pulmonary damage, which are common in MPO-ANCA-associated vasculitis, were almost absent but parapleural fibrosis was present. The direct cause of death was presumed to be hemorrhagic shock due to rupture of an aneurysm in the gastric subserosa. As far as we know, this is the first case of a systemic granulomatous reaction in MPO-ANCA-positive vasculitis, although the cause of the granulomatous lesion is unknown.

A case of Epstein-Barr Virus (EBV)-associated thymic carcinoid and investigation of existence of EBV-infected cells in thymus and thymic tumors

We describe the first case of Epstein-Barr virus (EBV)-associated thymic carcinoid tumor found by in situ hybridization (ISH) on paraffin-embedded sections. ISH revealed that both tumor cells and infiltrated lymphocytes were EBV positive, while a few EBV-infected lymphocytes were detected in 2 of 11 thymuses and 1 of 11 thymomas.

Identification of candidate microbial sequences from inflammatory lesion of giant cell arteritis

Giant cell arteritis (GCA) is a granulomatous inflammatory disease of medium and large arteries which is prevalent in the elderly population. The etiology of GCA is unknown, although the immunologic features suggest the possible presence of a microorganism. Our group has examined whether microbial DNA fragments were present at GCA lesions and whether such microbial fragments could be associated with disease pathogenesis. Initial identification of microbial sequences was performed using genomic representational difference analysis (RDA). Laser dissecting microscopy was used to isolate cells from GCA lesions and adjacent uninvolved temporal artery. Using genomic RDA, we isolated 10 gene fragments; three of these sequences had high homology with prokaryotic genes and were considered high-priority candidates for further study. An examination of serum from GCA(+) individuals (in contrast to healthy age-matched controls) showed the presence of IgG which recognized in vitro translated proteins from these clones.

Lymphocytic vasculitis in X-linked lymphoproliferative disease

Systemic vasculitis is an uncommon manifestation of X-linked lymphoproliferative disease (XLP), a disorder in which there is a selective immune deficiency to Epstein-Barr virus (EBV). The molecular basis for XLP has recently been ascribed to mutations within SLAM-associated protein (SAP), an SH2 domain-containing protein expressed primarily in T cells. The authors describe a patient who died as a result of chronic systemic vasculitis and fulfilled clinical criteria for the diagnosis of XLP. Sequencing of this patient's SAP gene uncovered a novel point mutation affecting the SH2 domain. The patient presented with virus-associated hemophagocytic syndrome (VAHS) and later had chorioretinitis, bronchiectasis, and hypogammaglobulinemia develop. He further developed mononeuritis and fatal respiratory failure. Evidence of widespread small and medium vessel vasculitis was noted at autopsy with involvement of retinal, cerebral, and coronary arteries as well as the segmental vessels of the kidneys, testes, and pancreas. Immunohistochemical analysis using antibodies to CD20, CD45RO, and CD8 revealed that the vessel wall infiltrates consisted primarily of CD8(+) T cells, implying a cytotoxic T-lymphocyte response to antigen. EBV DNA was detected by polymerase chain reaction (PCR) in arterial wall tissue microdissected from infiltrated vessels further suggesting that the CD8(+) T cells were targeting EBV antigens within the endothelium. The authors propose that functional inactivation of the SAP protein can impair the immunologic response to EBV, resulting in systemic vasculitis.