Serological and Molecular Characterization of Hepatitis C Virus-Related Cryoglobulinemic Vasculitis in Patients without Cryoprecipitate.

Prolonged B cells stimulation due to the Hepatitis C virus (HCV) can result in autoimmunity, stigmatized by rising levels of cryoglobulins (CGs), the rheumatoid factor (RF), and free light chains (FLC) of immunoglobulins (Ig) associated with a range of symptoms, from their absence to severe cryoglobulinemic vasculitis and lymphoma. Here, we aimed to identify an immunological signature for the earliest stages of vasculitis when cryoprecipitate is still not detectable. We firstly analyzed the IgG subclasses, FLC, and RF in 120 HCV-RNA-positive patients divided into four groups according to the type of cryoprecipitate and symptoms: 30 asymptomatic without cryoprecipitate (No Cryo), 30 with vasculitis symptoms but without CGs that we supposed were circulating but still not detectable (Circulating), 30 type II and 30 type III mixed cryoglobulinemia (Cryo II and Cryo III, respectively). Our results revealed that patients with supposed circulating CGs displayed a pattern of serological parameters that closely resembled Cryo II and Cryo III, with a stronger similarity to Cryo II. Accordingly, we analyzed the groups of Circulating and Cryo II for their immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) gene rearrangements, finding a similar mixed distribution of monoclonal, oligoclonal, and polyclonal responses compared to a control group of ten HCV-RNA-negative patients recovered from infection, who displayed a 100% polyclonal response. Our results strengthened the hypothesis that circulating CGs are the origin of symptoms in HCV-RNA-positive patients without cryoprecipitate and demonstrated that an analysis of clonal IGH and TCR rearrangements is the best option for the early diagnosis of extrahepatic complications.

Elevated Myl9 reflects the Myl9-containing microthrombi in SARS-CoV-2-induced lung exudative vasculitis and predicts COVID-19 severity.

The mortality of coronavirus disease 2019 (COVID-19) is strongly correlated with pulmonary vascular pathology accompanied by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-triggered immune dysregulation and aberrant activation of platelets. We combined histological analyses using field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy analyses of the lungs from autopsy samples and single-cell RNA sequencing of peripheral blood mononuclear cells to investigate the pathogenesis of vasculitis and immunothrombosis in COVID-19. We found that SARS-CoV-2 accumulated in the pulmonary vessels, causing exudative vasculitis accompanied by the emergence of thrombospondin-1-expressing noncanonical monocytes and the formation of myosin light chain 9 (Myl9)-containing microthrombi in the lung of COVID-19 patients with fatal disease. The amount of plasma Myl9 in COVID-19 was correlated with the clinical severity, and measuring plasma Myl9 together with other markers allowed us to predict the severity of the disease more accurately. This study provides detailed insight into the pathogenesis of vasculitis and immunothrombosis, which may lead to optimal medical treatment for COVID-19.

Autopsy-Based Pulmonary and Vascular Pathology: Pulmonary Endotheliitis and Multi-Organ Involvement in COVID-19 Associated Deaths.

BACKGROUND: Findings from autopsies have provided evidence on systemic microvascular damage as one of the underlying mechanisms of Coronavirus disease 2019 (CO-VID-19). The aim of this study was to correlate autopsy-based cause of death in SARS-CoV-2, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive patients with chest imaging and severity grade of pulmonary and systemic morphological vascular pathology. METHODS: Fifteen SARS-CoV-2 positive autopsies with clinically distinct presentations (age 22-89 years) were retrospectively analyzed with focus on vascular, thromboembolic, and ischemic changes in pulmonary and in extrapulmonary sites. Eight patients died due to COVID-19 associated respiratory failure with diffuse alveolar damage in various stages and/or multi-organ failure, whereas other reasons such as cardiac decompensation, complication of malignant tumors, or septic shock were the cause of death in 7 further patients. The severity of gross and histopathological changes was semi-quantitatively scored as 0 (absent), 1 (mild), and 3 (severe). Severity scores between the 2 groups were correlated with selected clinical parameters, initial chest imaging, autopsy-based cause of death, and compared using Pearson χ2 and Mann-Whitney U tests. RESULTS: Severe pulmonary endotheliitis (p = 0.031, p = 0.029) and multi-organ involvement (p = 0.026, p = 0.006) correlated significantly with COVID-19 associated death. Pulmonary microthrombi showed limited statistical correlation, while tissue necrosis, gross pulmonary embolism, and bacterial superinfection did not differentiate the 2 study groups. Chest imaging at hospital admission did not differ either. CONCLUSIONS: Extensive pulmonary endotheliitis and multi-organ involvement are characteristic autopsy features in fatal CO-VID-19 associated deaths. Thromboembolic and ischemic events and bacterial superinfections occur frequently in SARS-CoV-2 infection independently of outcome.

Cryoglobulins: Identification, classification, and novel biomarkers of mysterious proteins.

Cryoglobulins consist of serum immunoglobulins that precipitate below 37°C and resolubilize upon warming. The clinical triad of cryoglobulinemia usually includes purpura, weakness, and arthralgia. Cryoglobulinemic syndrome, clinically defined as a systemic vasculitis, is associated with chronic infection with hepatitis C virus (HCV) and autoimmune disorders and can evolve into B-cell malignancies. While the current literature about HCV-associated cryoglobulinemia is not very limited, little is known about the immunologic and serologic profiles of affected patients. Therefore, comprehension of the pathogenetic mechanisms underlying cryoprecipitation could be very helpful. Due to the persistence of viral antigenic stimulation, biomarkers to use after the worsening progression of HCV infection to lymphoproliferative and/or autoimmune diseases are widely needed. Laboratory methods used to detect and characterize low concentrations of cryoprecipitates and immunotyping patterns could improve patient management. The most critical factor affecting cryoglobulin testing is that the pre-analytical phase is not fully completed at 37°C.

Vascular Inflammation Is Associated with Loss of Aquaporin 1 Expression on Endothelial Cells and Increased Fluid Leakage in SARS-CoV-2 Infected Golden Syrian Hamsters.

Vascular changes represent a characteristic feature of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection leading to a breakdown of the vascular barrier and subsequent edema formation. The aim of this study was to provide a detailed characterization of the vascular alterations during SARS-CoV-2 infection and to evaluate the impaired vascular integrity. Groups of ten golden Syrian hamsters were infected intranasally with SARS-CoV-2 or phosphate-buffered saline (mock infection). Necropsies were performed at 1, 3, 6, and 14 days post-infection (dpi). Lung samples were investigated using hematoxylin and eosin, alcian blue, immunohistochemistry targeting aquaporin 1, CD3, CD204, CD31, laminin, myeloperoxidase, SARS-CoV-2 nucleoprotein, and transmission electron microscopy. SARS-CoV-2 infected animals showed endothelial hypertrophy, endothelialitis, and vasculitis. Inflammation mainly consisted of macrophages and lower numbers of T-lymphocytes and neutrophils/heterophils infiltrating the vascular walls as well as the perivascular region at 3 and 6 dpi. Affected vessels showed edema formation in association with loss of aquaporin 1 on endothelial cells. In addition, an ultrastructural investigation revealed disruption of the endothelium. Summarized, the presented findings indicate that loss of aquaporin 1 entails the loss of intercellular junctions resulting in paracellular leakage of edema as a key pathogenic mechanism in SARS-CoV-2 triggered pulmonary lesions.

[Varicella-zoster meningoencephalitis and vasculitis after treatment with amenamevir to herpes zoster in the trigeminal nerve area].

A 78-year-old woman was diagnosed with herpes zoster in the first branch of the trigeminal nerve and was treated with amenamevir. Subsequently, she was hospitalized for postherpetic neuralgia. Fever and unconsciousness were observed, and a diagnosis of varicella-zoster virus meningoencephalitis and vasculitis was made. In addition to the antithrombotic therapy, she was treated with intravenous acyclovir and steroid pulse therapy; however, her unconsciousness persisted. Amenamevir was not transferrable to the spinal fluid and resulted in an incomplete treatment of herpes zoster in the cerebral nerve region, suggesting that this case may be related to the severe course of the disease.

Coronavirus disease-19: The multi-level, multi-faceted vasculopathy.

BACKGROUND AND AIMS: The new coronavirus disease (COVID-19) is a systemic disease. Mounting evidence depict signs and symptoms involving multiple organs, most of which supported by pathological data. A plausible link to these manifestations is vascular and endothelial dysfunction/damage. However, much of the current knowledge relies on opinion and incipient evidence. We aim to objectively appraise current evidence on the association between COVID-19 and vascular disease, specifically endotheliitis and vasculitis. METHODS: Two researchers independently entered the search terms COVID-19 OR SARS-CoV-2 AND vasculitis, endotheliitis OR endothelium in the following online platforms: MedRxiv and LitCovid (PubMed). The search period was set from November 1, 2019 to August 28, 2020. Manuscripts with unavailable full texts, not in English, mainly on pre-clinical data, presenting only study designs or not directly related to the topics of this review were excluded. Retrospective and prospective studies, especially longitudinal ones, were given priority to the purpose of this review. Since there was paucity of prospective controlled evidence, case reports/series were also considered. RESULTS: A total of 318 manuscripts were initially found. Sixty-seven (21%) were excluded: 59 (18.5%) met exclusion criteria and 8 (2.5%) were duplicates. One hundred and forty-two manuscripts (44,6%) did not provide original data and were also excluded: 35 (11%) were comments, 108 (33.9%) reviews; 1 (0.3%) position paper. One hundred and seven (33.6%) studies were considered for the present scoping review: 81 (25,5%) case reports/series; 18 (5.7%) prospective; 8 (2.5%) retrospective. Viral inclusions in endothelial cells, mononuclear cell infiltrates in the intima of small vessels and markers of endothelial cell apoptosis were demonstrated. Specificities of COVID-19 may lead to diverse vascular manifestations in different levels of the vascular bed. CONCLUSIONS: Evidence indicates that COVID-19 targets vasculature and endothelium. However, high quality data is still lacking and studies with prospective designs and appropriately matched controls are needed.

Skin manifestations in COVID-19 patients, state of the art. A systematic review.

INTRODUCTION: Since COVID-19 has become a pandemic, extensive literature has been produced. The commonest symptoms of COVID-19 disease are fever, cough, anosmia, and lymphocytopenia. However, other apparently less common clinical symptoms have been described, including skin lesions. We conducted a systematic review to evaluate skin involvement in COVID-19. METHODS: The authors performed a systematic review of literature, in accordance with the Preferred Reporting Items for Systematic and Meta-Analysis (PRISMA). The search was reiterated until May 06, 2020. RESULTS: Overall, 1593 patients (M/F ratio: 1 : 9) with suspect of COVID-19 were examined. The mean age was 37.8 (range 0-91) years. Among the analyzed patients, 84 (5.3%) were pediatrics (<18 years). Chilblains are very common among skin lesions and represent almost half of all skin lesions reported (46%); in 75% of patients with cutaneous manifestation, the latter presented before other typical clinical manifestation of COVID-19. Vasculitis or thrombosis was identified in almost 70% of patients who suffered from skin manifestations. CONCLUSION: The present study highlights the importance of skin involvement in COVID-19. Limbs should be examined to eventually foresee the onset of further typical symptoms. Chilblains can be considered typical features. Studies with higher scientific evidence are required.

Hepatitis C virus-related vasculitis.

Cryoglobulinemic vasculitis (CryoVas) is a small-to-medium vessel systemic vasculitis caused by the deposition of mixed cryoglobulins and immune complexes. Clinical spectrum of CryoVas ranges from mild symptoms to vasculitis involving multiple organs that may progress to more life-threatening ilness. Hepatitis C virus (HCV) chronic infection is the most frequent condition to be assessed in patients with CryoVas. The mortality rate among patients with HCV-associated CryoVas is 3× that of the general population, with a 63% 10-year survival rate. The recent advent of interferon-free direct-acting antivirals (DAAs), which have the potential to induce sustained virological response rates greater than 95%, has dramatically changed the management of chronic HCV infection and HCV-related CryoVas. B-cell depleting strategies, mainly with rituximab, are the main therapeutic option in severe and refractory cases of HCV-associated CryoVas. Despite the progress in the last years on the management of chronic HCV infection, there are still unmet needs regarding therapeutic management of severe and refractory HCV-associated CryoVas.

Vascular neutrophilic inflammation and immunothrombosis distinguish severe COVID-19 from influenza pneumonia.

OBJECTIVE: Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can lead to severe pneumonia, but also thrombotic complications and non-pulmonary organ failure. Recent studies suggest intravascular neutrophil activation and subsequent immune cell-triggered immunothrombosis as a central pathomechanism linking the heterogenous clinical picture of coronavirus disease 2019 (COVID-19). We sought to study whether immunothrombosis is a pathognomonic factor in COVID-19 or a general feature of (viral) pneumonia, as well as to better understand its upstream regulation. APPROACH AND RESULTS: By comparing histopathological specimens of SARS-CoV-2 with influenza-affected lungs, we show that vascular neutrophil recruitment, NETosis, and subsequent immunothrombosis are typical features of severe COVID-19, but less prominent in influenza pneumonia. Activated neutrophils were typically found in physical association with monocytes. To explore this further, we combined clinical data of COVID-19 cases with comprehensive immune cell phenotyping and bronchoalveolar lavage fluid scRNA-seq data. We show that a HLADRlow CD9low monocyte population expands in severe COVID-19, which releases neutrophil chemokines in the lungs, and might in turn explain neutrophil expansion and pulmonary recruitment in the late stages of severe COVID-19. CONCLUSIONS: Our data underline an innate immune cell axis causing vascular inflammation and immunothrombosis in severe SARS-CoV-2 infection.

The coagulopathy, endotheliopathy, and vasculitis of COVID-19.

BACKGROUND: COVID-19-associated coagulopathy (CAC) characterized by the elevated D-dimer without remarkable changes of other global coagulation markers is associated with various thrombotic complications and disease severity. The purpose of this review is to elucidate the pathophysiology of this unique coagulopathy. METHODS: The authors performed online search of published medical literature through PubMed using the MeSH (Medical Subject Headings) term "COVID-19," "SARS-CoV-2," "coronavirus," "coagulopathy," and "thrombus." Then, selected 51 articles that closely relevant to coagulopathy in COVID-19. RESULTS: The primary targets of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are the pneumocytes, immune cells, and vascular endothelial cells. The alveolar damage and the pulmonary microvascular thrombosis are the major causes of acute lung injury in COVID-19. The endotheliopathy that occurs is due to direct SARS-CoV-2 infection and activation of other pathways that include the immune system and thromboinflammatory responses leading to what is termed CAC. As a result, both microvascular and macrovascular thrombotic events occur in arterial, capillary, venule, and large vein vascular beds to produce multiorgan dysfunction and thrombotic complications. In addition to the endothelial damage, SARS-CoV-2 also can cause vasculitis and presents as a systemic inflammatory vascular disease. Clinical management of COVID-19 includes anticoagulation but novel therapies for endotheliopathy, hypercoagulability, and vasculitis are needed. CONCLUSION: The endotheliopathy due to direct endothelial infection with SARS-COV-2 and the indirect damage caused by inflammation play the predominant role in the development of CAC. The intensive control of thromboinflammation is necessary to improve the outcome of this highly detrimental contagious disease.

Herpes simplex virus 2 vasculitis as cause of ischemic stroke in a young immunocompromised patient.

Herpes simplex virus 2 (HSV-2) is a very rare cause of central nervous system (CNS) infections. We report a case of a young woman with a left middle cerebral artery (MCA) ischemic stroke. The patient had history of HIV-1 infection, with periods of therapeutic non-compliance. Initial computed tomography (CT) imaging studies showed stenosis of the M1 segment of the left MCA, and magnetic resonance imaging (MRI) confirmed infarction of the MCA territory. Serial transcranial Doppler ultrasound revealed progressive occlusion of the MCA and stenosis of the left anterior cerebral artery. Systemic investigation for other causes of stroke was normal. Lumbar puncture revealed a mildly inflammatory cerebrospinal fluid, and HSV-2 DNA was identified by PCR, with a positive viral load in favor of active replication. No other viral or microbiological infections were identified. MRI angiography confirmed a vasculitic process involving the left carotid artery, and a HSV-2 vasculitis diagnosis was assumed. The patient started acyclovir with improvement of clinical features and imaging abnormalities. In the HIV-infected patient, stroke is a multifactorial common cause of morbidity. The physician should take into account a broad differential diagnosis including rare causes and atypical presentations of common etiologies, including HSV-1 and HSV-2 CNS infection.

Three Cases of Pediatric Multisystem Inflammatory Syndrome Associated with COVID-19 Due to SARS-CoV-2.

BACKGROUND Coronavirus disease 2019 (COVID-19) infection commonly presents as fever, cough, and shortness of breath in adults. Children are thought to have milder respiratory symptoms and to recover more quickly. We describe a new presentation of COVID-19 infection in children consisting of multisystem inflammation with decreased left ventricular function and evidence of lung disease. CASE REPORT Three children presented with fever, conjunctivitis, dry and cracked lips, rash, and/or cervical lymphadenopathy for at least 5 days. Two of these children required mechanical ventilation, and 1 of the 2 needed extracorporeal membrane oxygenation (ECMO) to support cardiorespiratory function. All of these children had moderate to severe hyponatremia and lymphopenia, which is usually seen in COVID-19. They were treated with intravenous immunoglobulin and high-dose aspirin. All of the children recovered. CONCLUSIONS Early recognition of children with multisystem inflammation is important because they are at increased risk for deterioration. Treatment with intravenous immunoglobulin and aspirin was used because this regimen has been shown to be beneficial in vasculitis of Kawasaki disease. The development of shock due to cardiac involvement may require ECMO.

Hepatitis B Virus-related Vasculitic Neuropathy in an Inactive Virus Carrier Treated with Intravenous Immunoglobulin.

We herein report a 33-year-old woman who was an asymptomatic hepatitis B virus (HBV) carrier and presented with distal muscle weakness in the legs and asymmetrical paresthesia in the distal extremities. A nerve biopsy specimen revealed fibrinoid necrosis associated with inflammatory infiltration in the perineural space, and deposition of hepatitis B core antigen and C4d complement was detected in the vascular endothelial cells as well as around the vessels. She was diagnosed with HBV-related vasculitic neuropathy and treated with intravenous immunoglobulin (IVIG). Her symptoms completely subsided after eight weeks. Vasculitic neuropathy rarely develops in the chronic inactive stages of HBV infection. This is the first report of an HBV-inactive carrier with vasculitic neuropathy successfully treated with IVIG.

COVID-19-associated vasculitis and vasculopathy.

The COVID-19 pandemic now totaling 13,000,000 cases and over 571,000 deaths has continued to teach the medical, scientific and lay communities about viral infectious disease in the modern era. Among the many lessons learned for the medical community is the potential for transmissibility and host infectivity of the SARS-CoV-2 virus. Moreover, it has become clear that the virus can affect any organ including the circulatory system, directly via either tissue tropism or indirectly stemming from inflammatory responses in the form of innate immunity, leukocyte debris such as cell-free DNA and histones and RNA viral particles. The following review considers COVID-19-associated vasculitis and vasculopathy as a defining feature of a virus-induced systemic disease with acute, subacute and potential chronic health implications.

SARS-CoV-2 endothelial infection causes COVID-19 chilblains: histopathological, immunohistochemical and ultrastructural study of seven paediatric cases.

BACKGROUND: Chilblains ('COVID toes') are being seen with increasing frequency in children and young adults during the COVID-19 pandemic. Detailed histopathological descriptions of COVID-19 chilblains have not been reported, and causality of SARS-CoV-2 has not yet been established. OBJECTIVES: To describe the histopathological features of COVID-19 chilblains and to explore the presence of SARS-CoV-2 in the tissue. METHODS: We examined skin biopsies from seven paediatric patients presenting with chilblains during the COVID-19 pandemic. Immunohistochemistry for SARS-CoV-2 was performed in all cases and electron microscopy in one. RESULTS: Histopathology showed variable degrees of lymphocytic vasculitis ranging from endothelial swelling and endotheliitis to fibrinoid necrosis and thrombosis. Purpura, superficial and deep perivascular lymphocytic inflammation with perieccrine accentuation, oedema, and mild vacuolar interface damage were also seen. SARS-CoV-2 immunohistochemistry was positive in endothelial cells and epithelial cells of eccrine glands. Coronavirus particles were found in the cytoplasm of endothelial cells on electron microscopy. CONCLUSIONS: Although the clinical and histopathological features were similar to other forms of chilblains, the presence of viral particles in the endothelium and the histological evidence of vascular damage support a causal relation of the lesions with SARS-CoV-2. Endothelial damage induced by the virus could be the key mechanism in the pathogenesis of COVID-19 chilblains and perhaps also in a group of patients severely affected by COVID-19 presenting with features of microangiopathic damage. What is already known about this topic? Despite the high number of cases of chilblains seen during the COVID-19 pandemic, a definite causative role for SARS-CoV-2 has not yet been proven. Different pathogenetic hypotheses have been proposed, including coagulation anomalies, interferon release and external factors. What does this study add? The demonstration of SARS-CoV-2 in endothelial cells of skin biopsies by immunohistochemistry and electron microscopy confirms that these lesions are part of the spectrum of COVID-19. Virus-induced vascular damage and secondary ischaemia could explain the pathophysiology of COVID-19 chilblains. Our findings support the hypothesis that widespread endothelial infection by SARS-CoV-2 could have a pathogenetic role in the severe forms of COVID-19. Linked Comment: Wetter. Br J Dermatol 2020; 183:611.