Anti-endothelial Cell Antibodies Research Articles

Anti-tubulin-alpha-1c antibody as a marker of value in Behçet syndrome

BackgroundBehçet’s syndrome (BS) is a multi-systemic vasculitis characterized by recurrent oral ulcers, genital ulcers, ocular lesions, and other systemic manifestations. As there is no laboratory diagnostics of BS, the diagnosis is mainly clinical.ObjectiveTo investigate the utility of the autoantibody against tubulin-α-1c in diagnosis of BS and its clinical significance.MethodsSixty BS patients and sixty healthy controls were enrolled in this study. We assessed all patients by Behçet disease current activity form (BDCAF), routine laboratory investigations, and immunological markers (ANA, anti-DNA, ANCA). Anti-endothelial cell antibodies (AECA) and anti-tubulin-alpha-1c antibodies were performed for all participants.ResultsRegarding duration of illness, Birmingham Vasculitis Activity Score (BVAS), and BDCAF, the mean value was 4.77 ± 4.239, 19.80 ± 10.020, and 9.52 ± 5.476, respectively. On comparing laboratory investigations, there was only significant increase in anti-tubulin-alpha-1c antibody in BS patients compared to healthy controls. Regarding AECA, there was no any significant correlation except with CRP. Anti-tubulin-alpha-1c detected significant direct correlation with the presence of posterior uveitis, panuveitis, and venous thrombosis as well as BVAS, C4, and protein/creatinine ratio. Regarding diagnostic performance of both AECA and anti-tubulin-alpha-1c, the cutoff value of AECA for diagnosis was 27.250, with sensitivity and specificity of 93.3% and 96.7%, respectively. The cutoff value of the anti-tubulin-alpha-1c for diagnosis was 22.300, with sensitivity and specificity of 100% and 96.7% respectively.ConclusionAnti-tubulin-α-1c antibodies are of diagnostic value in BS and are indicative of activity with 100% sensitivity and 96.7% specificity.Key Points• There is lack of specific laboratory, radiological, or histological diagnostics for Behcet syndrome.• We aimed to evaluate the significance of tubulin-α-1c autoantibody in diagnosis of Behcet syndrome.• There is elevation of tubulin-α-1c autoantibody with sensitivity and specificity of 100% and 96.7%, respectively.

Значение инфекции в развитии фетальных нарушений сердечного ритма

Objective. To assess the impact of infection on the development of fetal arrhythmias. Patients and methods. The study included 84 pregnant women who were divided into two groups: the study group, which consisted of 44 patients aged 20–42 years (Me 31 ± 0.93 years) with fetal arrhythmia and/or minor heart defects at 21–41 weeks’ gestation (Me 37.41 ± 0.58 weeks), and the comparison group, which enrolled 40 pregnant women without fetal heart defects and with normal fetal heart rate to determine the significance of serological markers of myocarditis. Results. Significant titers of non-specific anti-myocardial antibodies to vascular smooth muscle and endothelium were detected in 14 (31.8%) and 7 (15.9%) fetuses, respectively. “Conditionally positive” titers for anti-smooth muscle antibodies were detected in 3 (6.8%) fetuses and for anti-endothelial cell antibodies in 4 (9%) fetuses. There was no significant increase in specific anti-heart antibody titers in both groups. Conclusion. Hypoxia should be considered as a trigger for fetal arrhythmias. The infectious and inflammatory processes are one of the links in the pathogenesis of fetal arrhythmias. Key words: fetal arrhythmia, intrauterine infection, minor heart defects

Vascular Remodeling in Pulmonary Arterial Hypertension: The Potential Involvement of Innate and Adaptive Immunity.

Pulmonary arterial hypertension (PAH) is a severe disease with high morbidity and mortality. Current therapies are mainly focused on vasodilative agents to improve prognosis. However, recent literature has shown the important interaction between immune cells and stromal vascular cells in the pathogenic modifications of the pulmonary vasculature. The immunological pathogenesis of PAH is known as a complex interplay between immune cells and vascular stromal cells, via direct contacts and/or their production of extra-cellular/diffusible factors such as cytokines, chemokines, and growth factors. These include, the B-cell—mast-cell axis, endothelium mediated fibroblast activation and subsequent M2 macrophage polarization, anti-endothelial cell antibodies and the versatile role of IL-6 on vascular cells. This review aims to outline the major pathophysiological changes in vascular cells caused by immunological mechanisms, leading to vascular remodeling, increased pulmonary vascular resistance and eventually PAH. Considering the underlying immunological mechanisms, these mechanisms may be key to halt progression of disease.

Susac syndrome: challenges in the diagnosis and treatment.

Susac syndrome is a disorder thought to be mediated by an autoimmune response towards endothelial cells, leading to a characteristic clinical triad of encephalopathy, visual disturbances due to branch arterial occlusions and sensorineural hearing impairment. Although it is a rare disease, three reasons make it important. First, given its variable presentation, Susac syndrome is underdiagnosed. Second, it is considered an important differential diagnosis in different neurological, psychiatric, ophthalmological and hearing disorders, and consequently is frequently misdiagnosed. Third, in many cases, Susac syndrome is diagnosed and treated late, with significant irreversible sequelae including dementia, blindness and hearing loss. Neuropathology findings derived from both Susac syndrome patient tissue and novel transgenic mouse models indicate cytotoxic CD8+ T cells adhere to microvessels, inducing endothelial cell swelling, vascular narrowing and occlusion, causing microinfarcts. Anti-endothelial cell antibodies are present in serum in 25% of Susac syndrome patients, but it is unclear whether they are aetiologically related to the disease, or an epiphenomenon. The clinical triad comprising encephalopathy, branch arterial occlusions, and sensorineural hearing impairment is considered pathognomonic, although great variability is found in presentation and natural course of disease. At first evaluation, only 13-30% of patients exhibit the full clinical triad, making diagnosis difficult. Retinal fluorescein angiography, optic coherence tomography, MRI and tonal audiometry are helpful methods for diagnosing and monitoring disease activity during treatment. By contrast, there are no reliable objective immune markers to monitor disease activity. Immunosuppression is the current treatment, with high-dose corticosteroid therapy as the mainstay, but additional therapies such as intravenous immunoglobulins, cyclophosphamide, rituximab and mycophenolate mofetil are often necessary, because the disease can be devastating, causing irreversible organ damage. Unfortunately, low rates of disease, variability in presentation and paucity of objective biomarkers make prospective controlled clinical trials for Susac syndrome treatment difficult. Current immunosuppressive treatments are therefore based on empirical evidence, mainly from retrospective case series and expert opinion. In this review, we draw attention to the need to take consider Susac syndrome in the differential diagnosis of different neurological, psychiatric, ophthalmological and hearing disorders. Furthermore, we summarize our current knowledge of this syndrome, in reference to its pathophysiology, diagnosis and management, emphasizing the need for prospective and controlled studies that allow a better therapeutic approach.

The correlation of anti-heart antibodies levels with clinical manifestations and outcomes in patients with COVID-19

PurposeTo evaluate the blood level of anti-heart antibodies (AHA) and its correlation with clinical outcomes in patients with severe and moderate COVID-19.MethodsThe study included 34 patients (11 females and 23 males, mean age 58.3±17.6 years, from 20 to 87 years) who underwent treatment for moderate and severe COVID-19 at the Sechenov University hospital in April-June 2020. The diagnosis was confirmed by 50% using nasopharyngeal smears. In other cases, the diagnosis of COVID-19 was based on the following criteria: contact with a serologically confirmed COVID-19 patient, persistent fever of at least 38 degrees Celsius, typical CT findings of viral pneumonia, typical changes in blood tests in the absence of evidence for other diseases. Besides standard medical examination the AHA blood levels by immunoassay were observed, including antinuclear antibodies (ANA), antiendothelial cell antibodies (AECA), anti-cardiomyocyte antibodies (AbC), anti-smooth muscle antibodies (ASMA) and cardiac conducting tissue antibodies (CCTA). Median hospital length of stay was 14 [13; 18] days.ResultsAHA levels were increased in 25 (73.5%) patients. The patients were divided into the five groups: 1.Patients with previous chronic myocarditis who had already been receiving immunosuppressive therapy at the admission (n=4). Moderate titer increase was noted only in one patient. 2.Patients with severe COVID-19 and high inflammatory activity, in whom the degree of AHA increase matched the general disease activity. 3. Patients with severe COVID-19 and high inflammatory activity without AHA increase. 4. Patients with moderate COVID-19, in whom high AHA titers may reflect chronic latent myocarditis not associated with SARS-Cov2. 5. Patients with moderate COVID-19 and nearly normal / normal AHA titers. Significant correlation (p<0.05) of AHA levels with cardiovascular manifestations (r=0.459) was found. AbC levels correlated significantly with pneumonia severity (r=0.472), respiratory failure (r=0.387), need for invasive ventilation (r=0.469), chest pain (r=0.374), low QRS voltage (r=0.415) and high levels of CRP (r=0.360) and LDH (r=0.360). ASMA levels were found to correlate significantly with atrial fibrillation (r=0.414, p<0.05). ANA and AbC levels correlated significantly with pericardial effusion (r=0.721 and r=0.745 respectively, p<0.05). The lethality rate was 8.8%. AbC and ASMA levels correlated significantly with lethality (r=0.363, and r=0.426 respectively, p<0.05) and were prognostically important.ConclusionElevated titres of AHA were found in 73.5% of patients. AHA correlated with lethality, in most cases reflecting the overall activity and severity of the disease and may be considered within the systemic immune and inflammatory response in COVID-19. At the same time, the correlation with signs of myocardial injury and pericardial effusion, confirms the direct role of AHA in the inflammatory heart disease (myopericarditis).FUNDunding AcknowledgementType of funding sources: None.

A descriptive analysis of non-human leukocyte antigens present in renal transplant donor-recipient pairs

IntroductionEnd stage renal disease (ESRD) is the irreversible deterioration of renal function requiring renal replacement therapy by dialysis or transplant. Human leucocyte antigens (HLA) have been well examined however research still is required into the non-HLA antibodies. Antibody mediated rejection (AMR) can be seen in the absence of HLA antibodies on biopsies of patients who have received identical transplants; anti-endothelial cell antibodies may explain this. Investigation into endothelial cell antigens on donor and recipient endothelium may elucidate and stratify the degree of risk of any given transplant and may guide towards the best matched donor. MethodsProtein array analysis was carried out on 8 patient pairs using nitro-cellulose membranes and biotinylated detection antibodies. The fluorescence emitted was captured by X-Ray film and results were recorded with ImageJ software. A fold increase of more than 2 was considered to be positive. Results11 proteins identified had a fold increase of increase ≥2 and were present in ≥2 patient pairs which may point to potential clinical utility. Nectin2/CD112 may be measured in order analyse graft survival time in transplant recipients. Prognosticating renal failure has clinical importance and potential markers that have been identified to aid which include MEPE, CRELD2, and TIMP-4. Novel pharmacological therapies for specific biomarkers identified in this study include JAM-A, E-Selectin, CD147, Galectin-3, JAM-C, PAR-1, and TNFR2. ConclusionProtein analysis showed differences in expression of antigens between patients with and without Chronic Kidney Disease (CKD). This information could be used at the matching stage of renal transplantation and also in the treatment of rejection episodes. The results highlight biomarkers that potentially prognosticate and pharmacological therapies that may ameliorate kidney disease and rejection in ESRD and transplant recipients.

Autoimmune biomarkers in porto-sinusoidal vascular disease: Potential role in its diagnosis and pathophysiology.

Porto-sinusoidal vascular disease (PSVD) is a rare disease that requires excluding cirrhosis and other causes of portal hypertension for its diagnosis because it lacks a specific diagnostical test. Although it has been occasionally associated with autoimmune diseases, the pathophysiology of PSVD remains unknown. The aim of this study was to evaluate the potential role of autoimmunity in the pathophysiology and diagnosis of PSVD. Thirty-seven consecutive patients with PSVD and 39 with cirrhosis matched by gender, signs of portal hypertension and liver function were included (training set). By using Indirect Immunofluorescence, ELISA and slot-blot methods data 22 autoantibodies were identified in patients with PSVD and cirrhosis. Presence of anti-endothelial cells antibodies (AECA) was assayed by a cell-based ELISA. Thirty-one PSVD, 40 cirrhosis patients, 15 patients with splenomegaly associated with haematological disease and 14 healthy donors were included in a validation set. The proportion of patients with at least one positive antibody was statistically significantly higher in patients with PSVD compared with cirrhosis (92% vs 56%; P<.01). Specifically, AECA were significantly more frequent in PSVD than in cirrhosis (38% vs 15%; P=.013). Results were confirmed in the validation set. In the overall population, presence of AECA had a 63% positive predictive value for diagnosing PSVD and a 71% negative predictive value, with a specificity of 94% when the 1/16 level is used as cut-off. AECA positive serum samples react with a 68-72kDa protein of human liver endothelial sinusoidal cells.

Anti-heart antibodies levels and their correlation with clinical symptoms and outcomes in patients with confirmed or suspected diagnosis COVID-19.

The aim of this study is to evaluate the blood level of anti-heart antibodies (AHA) and its correlation with clinical outcomes in patients with severe and moderate coronavirus disease 2019 (COVID-19). The study included 34 patients (23 males; mean age 60.2 ± 16.6 years) with COVID-19 pneumonia. Besides standard medical examination, the AHA blood levels were observed, including antinuclear antibodies, antiendothelial cell antibodies, anti-cardiomyocyte antibodies (AbC), anti-smooth muscle antibodies (ASMA), and cardiac conducting tissue antibodies. Median hospital length of stay was 14 [13; 18] days. AHA levels were increased in 25 (73.5%) patients. Significant correlation (p < 0.05) of AHA levels with cardiovascular manifestations (r = 0.459) was found. AbC levels correlated with pneumonia severity (r = 0.472), respiratory failure (r = 0.387), need for invasive ventilation (r = 0.469), chest pain (r = 0.374), low QRS voltage (r = 0.415), and levels of C-reactive protein (r = 0.360) and lactate dehydrogenase (r = 0.360). ASMA levels were found to correlate with atrial fibrillation (r = 0.414, p < 0.05). Antinuclear antibodies and AbC levels correlated with pericardial effusion (r = 0.721 and r = 0.745, respectively, p < 0.05). The lethality rate was 8.8%. AbC and ASMA levels correlated significantly with lethality (r = 0.363 and r = 0.426, respectively, p < 0.05) and were prognostically important. AHA can be considered as part of the systemic immune and inflammatory response in COVID-19. Its possible role in the inflammatory heart disease requires further investigation.

Anticardiac antibodies in patients with severe and moderate COVID-19 (correlations with the clinical performance and prognosis)

The level and significance of anticardiac antibodies (ACA) in patients with COVID-19 infection have not yet been studied.Aim. To assess the level of various ACA in patients with severe and moderate COVID-19 infection and to identify the correlation of antibody profile with the clinical performance and prognosis.Material and methods. The study included 86 (38 women and 48 men) patients aged 20-90 years (60,2±16,6 years) who were hospitalized for moderate and severe COVID-19 infection in April-June 2020. Nasopharyngeal swab confirmed the disease in 59,3% of patients. In addition to the standard examination, electrocardiography and chest scan, level of antinuclear antibodies (ANA), antiendothelial cell antibodies (AECA), anti-cardiomyocyte antibodies, antibodies to anti-smooth muscles (ASMA) and cardiac conduction system fibers. Echocardiography was performed in 17 patients. Mean length of stay was 14 [12; 18] days. Death was considered as the primary endpoint.Results. Prevalence of heart disease and symptoms (including hypertension and coronary artery disease) was 45,3%. The manifestations of coronavirus heart damage include arrhythmias (supraventricular premature beats, 3,6%; atrial fibrillation, 9,3%), heart failure (9,3%), low QRS voltage (11,4%), repolarization abnormalities (41,9%), pericardial effusion (30%). An increase in troponin levels was observed in low number of patients. All types of cardiovascular disease correlated with the maximum D-dimer level (AUC, 0,752, p&lt;0,01). Titers of two or more types of ACA were increased by 3 or more times in 25 (73,5%) patients. Significant (p&lt;0,05) correlations of ANA level with cardiovascular symptoms/diseases in general (r=0,459), anti-cardiomyocyte antibodies — with the prevalence of pneumonia (r=0,472), shortness of breath severity (r=0,370), respiratory failure (r=0,387), oxygen therapy (r=0,388) and mechanical ventilation (r=0,469), as well as the presence of chest pain (r=0,374), QRS voltage decrease (r=0,415), maximum level of CRP (r=0,360) and LDH (r=0,360). ANA and anti-cardiomyocyte antibody levels strongly correlated with pericardial effusion (r=0,721 and r=0,745, respectively, p&lt;0,05). The mortality rate was 9,3%. Heart failure was one of the death causes in 37,5%. The level of anti-cardiomyocyte antibodies and ASMA correlated with mortality (r=0,363, and r=0,426, p&lt;0,05) and had a predictive value. Mortality in patients with cardiovascular disease was 17,9%, without — 2,2% (p&lt;0,05). The most powerful predictive model for COVID-19 adverse outcomes includes age, diabetes, oxygen therapy extent, maximum leukocyte, C-reactive protein and D-dimer levels. However, a model that includes only age, diabetes, and cardiovascular disease also has sufficient predictive power (correlation coefficient, 0,568, p&lt;0,001).Conclusion. An increase in ACA titers was detected in 73,5% of patients, correlated with mortality, in most cases reflects the general activity and severity of the disease and can be regarded as part of response in COVID-19. At the same time, a direct correlation with signs of myocardial damage, the presence and volume of pericardial effusion confirms the direct role of ACA in the development of myopericarditis.

Combination of chronic myocarditis and progressive coronary artery disease: differential diagnosis and stepwise treatment

Aim. To assess the differential diagnosis in a patient with a combination of coronary artery disease and myocarditis and the results of stepwise treatment (including immunosuppressive therapy (IST), and coronary stenting).Material and methods. A 56-year-old female patient with hypertension, obesity (body mass index, 31,6 kg/m2), diabetes and psoriasis developed shortness of breath after a respiratory viral infection. Primary echocardiography revealed left heart dilatation, ejection fraction (EF) of 21%. Coronary angiography revealed anterior descending artery stenosis of 75%, circumflex artery — 80%, right coronary artery (RCA) — 70%. RCA stenting was performed and cardiovascular and diuretic therapy was started. However, shortness of breath and low exercise tolerance persisted.Results. In the blood test, anti-endothelial cell antibodies were 1:320, anticardiomyocyte and anti-smooth muscle antibodies — 1:80, anti-cardiac conduction system fibers — 1:320 (N≤1:40). During myocardial perfusion scintigraphy with computed tomography, an uneven distribution of the indicator was noted. Signs of myocardial scarring and indications for further revascularization were not revealed. Cardiac magnetic resonance imaging confirmed a decrease in left ventricular (LV) contractility (LVEF 37%) and moderate dilatation. Biopsy was not performed due to dual antiplatelet therapy. The condition is regarded as infectious-immune myocarditis. IST was started with azathioprine 150 mg/day. We noted dyspnea relief and a stable increase in LVEF to 50-52%. The clinical course was complicated by sick sinus syndrome with pauses up to 6 seconds and presyncope; a pacemaker was implanted. After 5 years from the onset of IST, dyspnea episodes reappeared without exacerbation of myocarditis. As their cause, ischemia was diagnosed due to the progression of coronary atherosclerosis. Symptoms regressed after repeated coronary stenting.Conclusion. The presence of moderate coronary atherosclerosis without signs of ischemia and myocardial infarction should not be considered as the only cause of severe systolic myocardial dysfunction. Diagnosis and treatment of myocarditis in combination with coronary artery disease is carried out according to the standard principles and can improve LV systolic function and control the heart failure symptoms.

Pre-Transplant Angiotensin II Type 1 Receptor Antibodies and Anti-Endothelial Cell Antibodies Predict Graft Function and Allograft Rejection in a Low-Risk Kidney Transplantation Setting.

BackgroundNon-HLA antibodies, anti-angiotensin II type 1 receptor antibodies (anti-AT1R) and anti-endothelial cell antibodies (AECA), are known to play a role in allograft rejection. We evaluated the role of both antibodies in predicting post-transplant outcomes in low-risk living donor kidney transplantation (LDKT) recipients.MethodsIn 94 consecutive LDKT recipients who were ABO compatible and negative for pre-transplant HLA donor-specific antibodies, we determined the levels of anti-AT1Rs using an enzyme-linked immunosorbent assay and the presence of AECAs using a flow cytometric endothelial cell crossmatch (ECXM) assay with pre-transplant sera. Hazard ratio (HR) was calculated to predict post-transplant outcomes.ResultsPre-transplant anti-AT1Rs (≥11.5 U/mL) and AECAs were observed in 36 (38.3%) and 22 recipients (23.4%), respectively; 11 recipients had both. Pre-transplant anti-AT1Rs were a significant risk factor for the development of acute rejection (AR) (HR 2.09; P=0.018), while a positive AECA status was associated with AR or microvascular inflammation only (HR 2.47; P=0.004) throughout the follow-up period. In particular, AECA (+) recipients with ≥11.5 U/mL anti-AT1Rs exhibited a significant effect on creatinine and estimated glomerular filtration rate (P<0.001; P=0.028), although the risk of AR was not significant.ConclusionsPre-transplant anti-AT1Rs and AECAs have independent negative effects on post-transplant outcomes in low-risk LDKT recipients. Assessment of both antibodies would be helpful in stratifying the pre-transplant immunological risk, even in low-risk LDKT recipients.

Differences in anti-endothelial and anti-retinal antibody titers: implications for the pathohysiology of acute and chronic central serous chorioretinopathy.

The aim of the study was to evaluate the prevalence of serum anti-retinal (ARAs) and anti-endothelial cell antibodies (ACEAs) in patients with acute and chronic central serous chorioretinopathy (CSC). We enrolled 28 patients with acute CSC, 42 patients with chronic CSC, and 40 healthy controls. The presence of ARAs was determined by indirect immunofluorescence using monkey retina as an antigen substrate, while the presence of AECAs was determined using cultivated human umbilical vein endothelial cells (HUVECs) and primate skeletal muscle according to the manufacturer's instructions (Euroimmun AG). There were no differences in the prevalence of antibodies against rods, cones, cytoplasmic components of retinal nuclear layer cells, and retinal vessels between the acute and chronic CSC groups and the control group (P = 0.27, P = 0.16, P = 0.71, and P = 0.06, respectively). However, AECAs reactive with HUVECs were observed in 46% of patients with acute CSC, 45% of those with chronic CSC, and 22% of controls, whereas AECAs reactive with the skeletal muscle were present in 46%, 45%, and 15%, respectively (difference between groups: P = 0.045 for HUVECs and P = 0.005 for the skeletal muscle). Furthermore, AECA titers were higher in CSC patients than in controls (P = 0.004). This study provides evidence for the possible involvement of an autoimmune process directed against vessel antigens in the pathogenesis of CSC. AECAs may be more important than ARAs in this disease and may be involved in endothelial damage in the choroidal vessels and choriocapillaris, leading to hyperpermeability, which is central to the pathophysiology of CSC.

Single-cell analysis of autoreactive B cells in patients with systemic sclerosis revealed that responses to therapy are determined by effector and regulatory B cell balance

Abstract Objective Systemic sclerosis (SSc) is a connective tissue disease with poor prognosis. Although the standard treatment for skin and lung fibrosis is cyclophosphamide (CYC), there are not a few non-responders to the treatment. Recent studies showed that autoreactive B cells play a critical role in SSc. We hypothesized that these B cells determine the effectiveness of CYC treatment. We focused on cytokine profiles of single autoreactive B cells in patients with SSc. Methods We simulated the interaction of B cells and endothelial cells in microfluidic cell culture systems. We cultured endothelial cells in a microchannel. Then, we loaded B cells of patients with SSc. We collected single B cells which adhere to endothelial cells by trypsin treatment. We stimulated these B cells, with PMA and ionomycin, and measured the levels of produced interleukin (IL)-10 and IL-6 to detect the percentages of regulatory and effector B cells, by our original micro fluidic-ELISA system. Results In SSc patients, the number of B cells adhering to endothelial cells significantly increased compared with healthy controls. Most of these B cells produced anti-endothelial cells antibodies. The frequencies of IL-10-producing regulatory B cells after the CYC treatment increased in responders and decresed in non-responders. Those of IL-6-producing effector B cells after the treatment decreased in responders and increased in non-responders. Conclusions The effectiveness of CYC treatment to SSc patients is associated with cytokine profiles of B cells, which interact with endothelial cells. Checking the profiles of these B cells, after the first few months on from initiation of CYC therapy, may help to decide whether or not we should continue the treatment.

Identification of two major autoantigens negatively regulating endothelial activation in Takayasu arteritis

The presence of antiendothelial cell antibodies (AECAs) has been documented in Takayasu arteritis (TAK), a chronic granulomatous vasculitis. Here, we identify cell-surface autoantigens using an expression cloning system. A cDNA library of endothelial cells is retrovirally transfected into a rat myeloma cell line from which AECA-positive clones are sorted with flow cytometry. Four distinct AECA-positive clones are isolated, and endothelial protein C receptor (EPCR) and scavenger receptor class B type 1 (SR-BI) are identified as endothelial autoantigens. Autoantibodies against EPCR and SR-BI are detected in 34.6% and 36.5% of cases, respectively, with minimal overlap (3.8%). Autoantibodies against EPCR are also detected in ulcerative colitis, the frequent comorbidity of TAK. In mechanistic studies, EPCR and SR-BI function as negative regulators of endothelial activation. EPCR has also an effect on human T cells and impair Th17 differentiation. Autoantibodies against EPCR and SR-BI block the functions of their targets, thereby promoting pro-inflammatory phenotype.

P4494Renal insufficiency mitigates the protective effects of elevated anti endothelial cell antibodies on survival in patients undergoing coronary angiography

Abstract Background We previously demonstrated that elevated levels of antiendothelial cell antibodies are associated with improved survival of patients undergoing coronary angiography. However, renal insufficiency, which is associated with decreased survival, leads to increased level of the antiendothelial cell antibodies. The purpose of this study was to evaluate the correlation of the levels of these antibodies with survival in patients with normal versus reduced renal function. Patients and methods This was a single center prospective study. Eight hundred thirty eight consecutive patients undergoing coronary angiography with detectable antibody levels were enrolled. The levels of antiendothelial antibodies were determined by ELISA and measured in optical density units. Renal insufficiency was defined as adjusted GFR&lt;60 ml/min. The mean follow up was 30 months. Results Of total 838 patients, 481 (57%) had normal and 357 (42.6%) had reduced renal function. Total mortality was 13.6%, being significantly higher in patients with reduced (23.2%) versus normal (6.4%) renal function (p&lt;0.0001). Antiendothelial cell antibody levels were higher in patients with normal versus reduced renal function (4.76±7.05 versus 3.84±6.09 OD units, p=0.042). Antiendothelial cell antibody levels were significantly higher in survived versus deceased patients (4.56±6.82 versus 3.14±5.50 OD units, p=0.014). This association with survival was even more pronounced in patients with normal renal function (4.98±7.19 versus 11.69±3.29 OD units, p&lt;0.0001). In patients with reduced renal function, there was no significant difference between survived and deceased patients (3.89±6.12 versus 3.68±6.05 OD units, p=0.788). Conclusions Renal insufficiency leads to mild decrease in the antiendothelial cell antibodies' levels. Higher levels of antiendothelial cell antibodies are associated with improved survival in patients undergoing coronary angiography. This association is significant in patients with normal but not reduced renal function. Thus, the effect of the higher levels of these antibodies on survival cannot be explained by its association with renal dysfunction.

2018年系统性红斑狼疮研究新进展

To help to understand recent progresses in studies on systemic lupus erythematosus (SLE), the essence of the Fifth International Conference on SLE that was successfully held at Cancun, Mexico on April, 1998 is reviewed. Among more than 400 papers, most highlighted topics were (1) relationship between hyperprolactinemia and SLE, (2) molecular mechanisms of antiphospholipid syndrome, (3) roles of anti-endothelial cell antibodies, (4) apoptosis in pathogenesis, (5) autoimmunity against nucleosomes, (6) penetration of autoantibodies into living cells, and so on. Clinical studies on adverse effects of current therapies, pioneer cases of autologous stem cell transplantation for refractory SLE, and other numerous cases that were full of suggestiveness were also reported by physicians from many countries.

Expression of Concern: Circulating Anti-endothelial Cell Antibodies Are Associated with Poor Outcome in Renal Allograft Recipients with Acute Rejection.

Expression of Concern: Circulating Anti-endothelial Cell Antibodies Are Associated with Poor Outcome in Renal Allograft Recipients with Acute Rejection.

Susac syndrome with negative anti-endothelial cell antibody: a case report

本文报道血清抗内皮细胞抗体（AECA）阴性SUSAC综合征一例。患者男，29岁，因头痛、恶心、呕吐、反应迟钝、嗜睡、言语不流利，走路不稳就诊。颅脑MRI检查示双侧半卵圆中心、胼胝体多发小斑点、斑片状长T1、长T2异常信号灶，液体衰减反转恢复（FLAIR）序列T2WI呈高信号，矢状面T2WI图像示胼胝体病灶呈轮辐放射状分布。眼底荧光造影示双眼视网膜分支动静脉不同程度充盈缺损、双眼视野部分缺失。电测听示双耳感音神经性听力下降。

Anti-endothelial cell antibodies are associated with apoptotic endothelial microparticles, endothelial sloughing and decrease in angiogenic progenitors in systemic sclerosis.

IntroductionEvidence has accumulated for the role of endothelial damage in systemic sclerosis (SSc) and the anti-endothelial cell antibodies (AECAs) might underlie vascular injury.AimSince endothelial microparticles (EMPs) and circulating endothelial cells (CECs) reflect endothelial damage, we aimed to investigate their possible relationship with AECAs in SSc. We examined whether AECAs could affect endothelial repair based on the number of endothelial progenitor cells (EPCs).Material and methodsForty-seven SSc patients were screened. The AECAs were identified in serum by indirect immunofluorescence. EPCs and CECs were isolated from the peripheral blood using anti-CD34-based immunomagnetic separation, whereas EMPs were analyzed in plasma. Flow cytometry was used to quantify EMPs, CECs and EPCs.ResultsAECAs were found in 21 (44.7%) SSc patients and were significantly associated with higher levels of total as well as apoptotic (AnnV+ and CD51+) EMPs, whereas activated (CD62E+/AnnV–) EMPs did not differ between groups. Patients with AECAs had significantly elevated total CECs as well as activated CD105+ CECs. Total endothelial progenitors did not differ between patients with or without AECAs; however AECAs was negatively associated with the population of EPCs that express VEGFR2 or Tie2 receptors.ConclusionsWe found an association between AECAs and the severity of endothelial damage in SSc based on higher levels of total EMPs and CECs. In our study, AECAs were associated with apoptosis of ECs rather than their activation. We also identified a possible role of AECAs in the impairment of vascular repair in SSc as evidenced by significantly fewer angiogenic EPCs.

Non-HLA Antibodies as a Cause for Biopsy Negative Rejection: Is It Worth Testing for Them?

Purpose Biopsy negative rejection (BNR) after heart transplantation is not uncommon. BNR is diagnosed when there is an acute reduction in cardiac function along with symptoms of heart failure. As the endomyocardial biopsy shows no rejection, a search for other causes is pursued. Non-HLA antibodies may not demonstrate C4d deposition in the heart biopsy therefore remains a possible cause of this form of rejection. It is not clear if non-HLA antigens are detected during these cases. Therefore, we reviewed our experience with BNR and detection of non-HLA antibodies. Methods Between 2000 and 2017 we performed 1391 heart transplants and identified 96 cases of BNR (6.9%). Non-HLA antibodies were obtained at the time of BNR and included angiotensin type 1 receptor (AT1R), major-histocompatibility-complex (MHC) class I-related chain A (MICA) and anti-endothelial cell antibodies. All patients with BNR were treated with various anti-rejection regimens including high dose corticosteroids, immune globulin (IVIG), anti-lymphocyte globulin (ATG) and/or plasmapheresis. Results BNR was detected in 96 patients. The following non-HLA antibodies were detected: AT1R (15 patients), MICA (7 patients), and anti-endothelial cell antibodies (3 patients). This constituted 26% of BNR patients. 24% percent of patients recovered with initial anti-humoral therapy. The percent of BNR with anti-HLA antibodies was 12.0% percent. Conclusion BNR is not uncommon after heart transplantation. Non-HLA antibodies are observed in approximately 26.0% percent of patients with BNR, thus, non-HLA testing is worthwhile to initiate appropriate anti-rejection therapy.