Cardiovascular disease biomarkers across autoimmune diseases

Endothelial cell activation and glycocalyx shedding - potential as biomarkers in patients with lupus nephritis

Lupus nephritis (LN) is a common and severe manifestation of systemic lupus erythematosus and an important cause of acute and chronic kidney injury. Early diagnosis of LN and preventing relapses are key to preserving renal reserve. However, due to the complexity and heterogeneity of the disease, clinical management remains challenging. Kidney biopsy remains the gold standard for confirming the diagnosis of LN and subsequent assessment of kidney histopathology, but it is invasive and cannot be repeated frequently. Current clinical indicators of kidney function such as proteinuria and serum creatinine level are non-specific and do not accurately reflect histopathological changes, while anti-dsDNA antibody and C3 levels reflect immunological status but not kidney injury. Identification of novel and specific biomarkers for LN is prerequisite to improve management. Renal function deterioration is associated with changes in the endothelial glycocalyx, a delicate gel-like layer located at the interface between the endothelium and bloodstream. Inflammation induces endothelial cell activation and shedding of glycocalyx constituents into the circulation. This review discusses the potential role of soluble glycocalyx components as biomarkers of active LN, especially in patients in whom conventional serological and biochemical markers do not appear helpful.

Pre-Existing Autoimmune Disease Increases the Risk of Cardiovascular and Noncardiovascular Events After Immunotherapy

Background

The use of immune checkpoint inhibitors (ICI) is associated with cardiovascular (CV) events, and patients with pre-existing autoimmune disease are at increased CV risk.

Objectives

The aim of this study was to characterize the risk for CV events in patients with pre-existing autoimmune disease post-ICI.

Methods

This was a retrospective study of 6,683 patients treated with ICIs within an academic network. Autoimmune disease prior to ICI was confirmed by chart review. Baseline characteristics and risk for CV and non-CV immune-related adverse events were compared with a matched control group (1:1 ratio) of ICI patients without autoimmune disease. Matching was based on age, sex, history of coronary artery disease, history of heart failure, and diabetes mellitus. CV events were a composite of myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft, stroke, transient ischemic attack, deep venous thrombosis, pulmonary embolism, or myocarditis. Univariable and multivariable Cox proportional hazards models were used to determine the association between autoimmune disease and CV events.

Results

Among 502 patients treated with ICIs, 251 patients with and 251 patients without autoimmune disease were studied. During a median follow-up period of 205 days, there were 45 CV events among patients with autoimmune disease and 22 CV events among control subjects (adjusted HR: 1.77; 95% CI: 1.04-3.03; P = 0.0364). Of the non-CV immune-related adverse events, there were increased rates of psoriasis (11.2% vs 0.4%; P < 0.001) and colitis (24.3% vs 16.7%; P = 0.045) in patients with autoimmune disease.

Conclusions

Patients with autoimmune disease have an increased risk for CV and non-CV events post-ICI.

DBA/1 mice display equivalent cardiac function to C57BL/6J mice

NEW FINDINGS

What is the central question of this study? Do normal adult DBA/1 mice have cardiac function and performance equal to those of C57BL/6J mice? What is the main finding and its importance? Male adult DBA/1 mice show equivalent cardiac function to C57BL/6J mice up to 8 months old. Therefore, cardiac dysfunction could be investigated in an autoimmune diseases model established with DBA/1 mice.

ABSTRACT

Cardiovascular mortality has been increasing, and in particular, cardiovascular damage caused by some chronic autoimmune diseases accounts for a large proportion of this. C57BL/6J mice have been used mostly in studies of cardiovascular diseases. However, for purposes of modelling, this strain of mouse has a very low incidence of some chronic immune diseases such as rheumatoid arthritis, to which instead DBA/1 mice are more susceptible. Basic cardiac function differs between mice with different genetic backgrounds. Therefore, we monitored cardiac function and structure of normal male C57BL/6J and DBA/1 mice for six consecutive months. Echocardiography was used to monitor cardiac functions once a month and cardiac systolic function was measured upon isoproterenol challenge at the end of observation. The Excitation-contraction coupling-related proteins were measured by western blotting. Heart tissue sections were subject to haematoxylin-eosin, TUNEL and Alizarin red staining. The results demonstrated that systolic and diastolic function did not vary significantly and both strains were indistinguishable in appearance and structure of hearts. DBA/1 mice showed a good cardiac β-adrenergic response comparable to C57BL/6J mice with isoproterenol treatment. The phosphorylation of phospholamban at either its protein kinase A or its Ca²⁺ /calmodulin-dependent protein kinase II site, as well as the activation of troponin I showed no significant difference between strains. These findings suggested that there was no obvious difference in the heart structure and function of normal male DBA/1 mice compared with C57BL/6J mice. The DBA/1 mouse is a strain applicable to investigating autoimmune disease-induced heart dysfunction and exploring potential interventions.

Growth Differentiation Factor-15 as a Potent Predictor of Long-Term Mortality among Subjects with Osteoarthritis

Background: Subjects with osteoarthritis (OA) are at increased risk for cardiovascular (CV) and all-cause mortality. Whether biomarkers improve outcome prediction in these patients remains to be elucidated. We investigated the association between growth differentiation factor 15 (GDF-15), a novel stress-responsive cytokine, and long-term all-cause mortality among OA patients. Methods: Within the Ulm Osteoarthritis Study, GDF-15 has been measured in the serum of 636 subjects, who underwent hip or knee arthroplasty between 1995 and 1996 (median age 65 years). Results: During a median follow-up of 19.7 years, a total of 402 deaths occurred. GDF-15 was inversely associated with walking distance. Compared to the bottom quartile (Q), subjects within the top quartile of GDF-15 demonstrated a 2.69-fold increased risk of dying (hazard ratio (HR) (95% confidence interval (CI)) 2.69 (1.82–3.96) adjusted for age, sex, BMI, smoking status, localization of OA, diabetes, maximum walking distance, total cholesterol, and cystatin C. Further adjustment for NT-proBNP, troponin I, and hs-C-reactive protein did not change the results appreciably (HR (95%CI) 1.56 (1.07–2.28); 1.75 (1.21–2.55); 2.32 (1.55–3.47) for Q2, Q3, and Q4 respectively, p for trend < 0.001). Conclusions: In subjects with OA, GDF-15 represents a potent predictor of decreased survival over >20 years, independently of conventional CV risk factors, renal, cardiac, and inflammatory biomarkers as well as walking disability, previously associated with increased mortality and lower extremity OA.

Global expression and CpG methylation analysis of primary endothelial cells before and after TNFa stimulation reveals gene modules enriched in inflammatory and infectious diseases and associated DMRs

Endothelial cells are a primary site of leukocyte recruitment during inflammation. An increase in tumor necrosis factor-alpha (TNFa) levels as a result of infection or some autoimmune diseases can trigger this process. Several autoimmune diseases are now treated with TNFa inhibitors. However, genomic alterations that occur as a result of TNF-mediated inflammation are not well understood. To investigate molecular targets and networks resulting from increased TNFa, we measured DNA methylation and gene expression in 40 human umbilical vein endothelial cell primary cell lines before and 24 hours after stimulation with TNFa via microarray. Weighted gene co-expression network analysis identified 15 gene groups (modules) with similar expression correlation patterns; four modules showed a strong association with TNFa treatment. Genes in the top TNFa-associated module were all up-regulated, had the highest proportion of hypomethylated regions, and were associated with 136 Disease Ontology terms, including autoimmune/inflammatory, infectious and cardiovascular diseases, and cancers. They included chemokines CXCL1, CXCL10 and CXCL8, and genes associated with autoimmune diseases including HLA-C, DDX58, IL4, NFKBIA and TNFAIP3. Cardiovascular and metabolic disease genes, including APOC1, ACLY, ELOVL6, FASN and SCD, were overrepresented in a module that was not associated with TNFa treatment. Of 223 hypomethylated regions identified, several were in promoters of autoimmune disease GWAS loci (ARID5B, CD69, HDAC9, IL7R, TNIP1 and TRAF1). Results reveal specific gene groups acting in concert in endothelial cells, delineate those driven by TNFa, and establish their relationship to DNA methylation changes, which has strong implications for understanding disease etiology and precision medicine approaches.

Inclusion body myositis: clinical features and pathogenesis

Inclusion body myositis (IBM) is often viewed as an enigmatic disease with uncertain pathogenic mechanisms and confusion around diagnosis, classification and prospects for treatment. Its clinical features (finger flexor and quadriceps weakness) and pathological features (invasion of myofibres by cytotoxic T cells) are unique among muscle diseases. Although IBM T cell autoimmunity has long been recognized, enormous attention has been focused for decades on several biomarkers of myofibre protein aggregates, which are present in <1% of myofibres in patients with IBM. This focus has given rise, together with the relative treatment refractoriness of IBM, to a competing view that IBM is not an autoimmune disease. Findings from the past decade that implicate autoimmunity in IBM include the identification of a circulating autoantibody (anti-cN1A); the absence of any statistically significant genetic risk factor other than the common autoimmune disease 8.1 MHC haplotype in whole-genome sequencing studies; the presence of a marked cytotoxic T cell signature in gene expression studies; and the identification in muscle and blood of large populations of clonal highly differentiated cytotoxic CD8⁺ T cells that are resistant to many immunotherapies. Mounting evidence that IBM is an autoimmune T cell-mediated disease provides hope that future therapies directed towards depleting these cells could be effective.

Inflammation in atherosclerotic cardiovascular disease

Atherosclerotic cardiovascular disease is a leading cause of death and morbidity globally. Over the past several years, arterial inflammation has been implicated in the pathophysiology of athero-thrombosis, substantially confirming what pathologist Rudolf Virchow had observed in the 19th century. Lipid lowering, lifestyle changes, and modification of other risk factors have reduced cardiovascular complications of athero-thrombosis, but a substantial residual risk remains. In view of the pathogenic role of inflammation in athero-thrombosis, directly targeting inflammation has emerged as an additional potential therapeutic option; and some early promising results have been suggested by the Canakinumab Anti-inflammatory Thrombosis Outcome Study (CANTOS), in which canakinumab, a fully human monoclonal antibody targeting the pro-inflammatory and pro-atherogenic cytokine interleukin 1 beta, was shown to reduce cardiovascular events.

Oxidative stress markers in patients with hereditary angioedema

INTRODUCTION

Hereditary angioedema due to C1-INH deficiency (C1-INH-HAE) or with normal C1-INH is characterized by recurrent swellings due to uncontrolled production of vasoactive mediators, among which bradykinin (BK) is crucial. Through the binding and activation of the two human BK-receptors, kinins may have dual beneficial and deleterious effects in vascular and inflammation physiopathology by inducing oxidative stress. We aimed to assess the serum concentrations of advanced glycation end products (AGEs) and advanced oxidation protein products (AOPPs) in patients affected by HAE.

MATERIAL AND METHODS

Blood samples were collected to measure the serum concentrations of AGEs and AOPPs by spectrofluorimetric and spectrophotometric methods in patients affected by C1-INH-HAE and FXII-HAE during the remission state.

RESULTS

We showed that the circulating levels of AOPPs observed on control group (0.94 (0.36) nmol/mg) were significantly lower than those observed on the C1-INH-HAE group (1.68 (0.47) nmol/mg; p = 0.002) and FXII-HAE (1.50 (0.27) nmol/mg; p = 0.001). Moreover, the circulating levels of AGEs were significantly higher in C1-INH-HAE group (211.58 (151.05) AU/g; p = 0.02) than the FXII group (141.48 (89.59) AU/g), thus demonstrating a state of heightened oxidative stress.

CONCLUSIONS

Our observations show additional underlying events involved in HAE and are of central importance for further investigations of differences in bradykinin receptors signaling among the two disease subgroups.

Health care costs and comorbidities for patients with inclusion body myositis

OBJECTIVE

This study identifies the health care costs and utilization, as well as comorbidities, in a Medicare population of inclusion body myositis (IBM) patients.

METHODS

Medicare patients aged ≥65 years with a diagnosis claim for IBM were identified and matched to a cohort of non-IBM patients based on age, sex, race, calendar year and census region. Generalized linear models were used to estimate health care costs and utilization during the follow-up period.

RESULTS

The prevalence of IBM in this population, aged ≥65 years, was 83.7 cases per 1 million patients. Mean 1 year costs for the IBM cohort (N = 361) were $44,838 compared to $10,182 for the matched non-IBM cohort (N = 1805), an excess of $34,656. IBM was significantly associated with multiple unsuspected comorbidities, including hypertension (66% vs. 22%), hyperlipidemia (47% vs. 18%) and myocardial infarction (13% vs. 2%) (all p < .0001).

CONCLUSIONS

IBM patients utilize more health care resources and incur higher health care costs than patients without IBM. Furthermore, IBM patients were more likely to have multiple comorbidities, including cardiovascular risk factors and events, muscle and joint pain, and pulmonary complications compared to those without IBM.

LIMITATIONS

The presence of a diagnosis code for a condition on a medical claim does not necessarily indicate the presence of the disease condition because the diagnosis code could be incorrectly entered in the database. Clinical and disease-specific parameters were not available in the claims data. Additionally, due to the observational study design, the analysis may be affected by unobserved differences between patients.

The pulse-mass index as a predictor of cardiovascular events in women with systemic lupus erythematosus

BACKGROUND

Patients with systemic lupus erythematosus (SLE) have 3times the risk of death compared to the rest of the population, with cardiovascular events (CVD) being one of the main causes. Índices such as waist-height (W-Ht I), waist-hip (W-Hp I) and pulse-mass (PMI) predict CVD, though the behaviour is unknown in patients with SLE. The aim of this study was to determine the prognostic value of PMI in the development of CVD in premenopausal women with SLE.

METHODOLOGY

Cohort study. Included were premenopausal women with SLE without prior CVD; excluded were those patients with antiphospholipid syndrome (APS), pregnancy, thyroid disease, recent liposuction, and chronic kidney disease. Exposure variables were: PMI, W-Ht I, W-Hp I and metabolic syndrome at onset of the cohort. Considered confounding variables were time of evolution, disease activity, cumulative damage and treatment. Through semi-annual appointments, accident and emergency admittance and hospitalisation records the CVD were screened. Analysis was performed with Cox for proportional hazards and survival with Kaplan Meier.

RESULTS

We included 238 women with a median age of 31 (18-52) years, with a follow-up of 8years. We identified 22 (9.6%) cases of CVD. In the Cox proportional hazards analysis, the prognostic variables were: PMI with HR=8.1 (95% CI: 1.1-65), metabolic syndrome with 2.4 (95% CI: 1-5.8), cumulative damage with HR=1.5 (95% CI: 1.1-2.2) and body fat percentage HR=2.8 (95% CI: 1.1-6.9) CONCLUSIONS: The PMI is a better predictor factor of CVD in women with SLE.

[New populations at increased cardiovascular risk: Cardiovascular disease in dermatological diseases]

The increased cardiovascular risk in some dermatological diseases has been demonstrated in recent decades. Diseases such as psoriasis and systemic lupus erythematosus are currently included in the guidelines for prevention of cardiovascular disease. Other diseases such as androgenic alopecia, polycystic ovary syndrome, hidradenitis suppurativa or lichen planus have numerous studies that point to an increased risk, however, they have not been included in these guidelines. In this article we review the evidence supporting this association, in order to alert the clinician to the need for greater control in cardiovascular risk factors in these patients.

The Prevalence of Atherosclerosis in Those with Inflammatory Connective Tissue Disease by Race, Age, and Traditional Risk Factors

Systemic inflammation promotes cardiovascular disease. Inflammatory connective tissue diseases (CTD) like lupus and rheumatoid arthritis associate with cardiovascular risk, but it is unknown whether particular groups of patients have enhanced propensity for atherosclerotic cardiovascular disease (ASCVD) associated with their CTD. Analysis of aggregate health record data at a large U.S. academic center identified CTD and ASCVD status for 287,467 African American and white adults. ASCVD prevalence in those with CTD was 29.7% for African Americans and 14.7% for white patients with prevalence ratios, compared to those without CTD, of 3.1 and 1.8, respectively. When different types of CTD were analyzed individually (rheumatoid arthritis; lupus; scleroderma; Sjögren Syndrome; dermatomyositis/polymyositis; unspecified/mixed CTD; other inflammatory arthropathy), increased ASCVD rates were found in nearly all subsets, always with higher prevalence ratios in African Americans. The prevalence ratio of ASCVD was particularly high in young African Americans. Furthermore, individuals lacking traditional cardiovascular risk factors had more ASCVD if they had CTD (prevalence ratio 2.9). Multivariate analysis confirmed a positive interaction between CTD and African-American race and a negative interaction between CTD and age. The factors driving the observed disproportionate CTD-associated ASCVD in African Americans, young adults, and those without traditional risk factors warrant further study.