Immunomodulation of vascular diseases: atherosclerosis and autoimmunity

Colchicine for the primary prevention of cardiovascular events

BACKGROUND

Atherosclerotic cardiovascular diseases (ACVDs), a condition characterised by lipid accumulation in arterial walls, which is often exacerbated by chronic inflammation disorders, is the major cause of mortality and morbidity worldwide. Colchicine, with its first medicinal use in ancient Egypt, is an inexpensive drug with anti-inflammatory properties. However, its role in primary prevention of ACVDs in the general population remains unknown.

OBJECTIVES

To assess the clinical benefits and harms of colchicine as primary prevention of cardiovascular outcomes in the general population.

SEARCH METHODS

We searched the Cochrane Heart Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Ovid MEDLINE (including In-Process & Other Non-Indexed Citations), Ovid Embase, Web of Science, and LILACS. We searched ClinicalTrials.gov and WHO ICTRP for ongoing and unpublished studies. We also scanned the reference lists of relevant included studies, reviews, meta-analyses, and health technology reports to identify additional studies. There were no limitations on language, date of publication, or study setting. The search results were updated on 31 May 2023.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in any setting, recruiting adults without pre-existing cardiovascular disease. We included trials that compared colchicine versus placebo, non-steroidal anti-inflammatory drugs, corticosteroids, immunomodulating drugs, or usual care. Our primary outcomes were all-cause mortality, non-fatal myocardial infarction, stroke, and adverse events.

DATA COLLECTION AND ANALYSIS

Two or more review authors independently selected studies, extracted data, and performed risk of bias and GRADE assessments.

MAIN RESULTS

We identified 15 RCTs (1721 participants randomised; 1412 participants analysed) with follow-up periods ranging from 4 to 728 weeks. The intervention was oral colchicine compared with placebo, immunomodulating drugs, or usual care or no treatment. Due to biases and imprecision, the evidence was very uncertain for all outcomes. All trials but one had a high risk of bias. Five out of seven meta-analyses included fewer than six trials (71.4%). The objectives of the review were to assess cardiovascular outcomes in the general population, but many of the included trials focused on liver disease. Colchicine compared to placebo Colchicine may reduce all-cause mortality compared to placebo in primary prevention, but the evidence is very uncertain (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.51 to 0.91; 6 studies, 463 participants; very low-certainty evidence; number needed to treat for an additional beneficial outcome (NNTB) 11, 95% CI 6 to 67). Colchicine may result in little to no difference in non-fatal myocardial infarction, but the evidence is very uncertain (RR 0.87, 95% CI 0.41 to 1.82; 1 study, 100 participants; very low-certainty evidence). Colchicine may not reduce the incidence of stroke, but the evidence is very uncertain (RR 2.43, 95% CI 0.67 to 8.86; 1 study, 100 participants; very low-certainty evidence). Regarding adverse events, colchicine may increase the incidence of diarrhoea (RR 3.99, 95% CI 1.44 to 11.06; 8 studies, 605 participants; very low-certainty evidence; number needed to treat for an additional harmful outcome (NNTH) 10, 95% CI 6 to 17), and may have little to no effect on neurological outcomes such as seizure or mental confusion (RR 0.72, 95% CI 0.31 to 1.66; 2 studies, 155 participants; very low-certainty evidence), but the evidence is very uncertain. The effect of colchicine on cardiovascular mortality is also very uncertain (RR 1.27, 95% CI 0.03 to 62.43; 2 studies, 160 participants; very low-certainty evidence). Colchicine may not reduce post-cardiac procedure atrial fibrillation, but the evidence is very uncertain (RR 0.74, 95% CI 0.25 to 2.19; 1 study, 100 participants). We found no trials reporting on pericardial effusion, peripheral artery disease, heart failure, or unstable angina. Colchicine compared to methotrexate (immunomodulating drug) Colchicine may result in little to no difference in all-cause mortality compared to methotrexate, but the evidence is very uncertain (RR 0.42, 95% CI 0.12 to 1.51; 1 study, 85 participants; very low-certainty evidence). We found no trials reporting other cardiovascular outcomes or adverse events for this comparison. Colchicine compared to usual care or no treatment The evidence is very uncertain about the effect of colchicine compared with usual care on all-cause mortality in primary prevention (RR 1.07, 95% CI 0.90 to 1.27; 2 studies, 729 participants; very low-certainty evidence). Regarding adverse events, colchicine may increase the incidence of diarrhoea compared to usual care, but the evidence is very uncertain (RR 3.32, 95% CI 1.56 to 7.03; 2 studies, 729 participants; very low-certainty evidence; NNTH 18, 95% CI 12 to 42). No trials reported other cardiovascular outcomes for this comparison.

AUTHORS' CONCLUSIONS

This Cochrane review evaluated the clinical benefits and harms of using colchicine for the primary prevention of cardiovascular events in the general population. Comparisons were made against placebo, immunomodulating medications, or usual care or no treatment. However, the certainty of the evidence for the predefined outcomes was very low, highlighting the pressing need for high-quality, rigorous studies to ascertain colchicine's clinical impact definitively. We identified numerous biases and inaccuracies in the included studies, limiting their generalisability and precluding a conclusive determination of colchicine's efficacy in preventing cardiovascular events. The existing evidence regarding colchicine's potential cardiovascular benefits or harms for primary prevention is inconclusive owing to the limitations inherent in the current studies. More robust clinical trials are needed to bridge this evidence gap effectively.

Autoimmune Responses and Therapeutic Interventions for Systemic Lupus Erythematosus: A Comprehensive Review

Systemic Lupus Erythematosus (SLE) or Lupus is a multifactorial autoimmune disease of multiorgan malfunctioning of extremely heterogeneous and unclear etiology that affects multiple organs and physiological systems. Some racial groups and women of childbearing age are more susceptible to SLE pathogenesis. Impressive progress has been made towards a better understanding of different immune components contributing to SLE pathogenesis. Recent investigations have uncovered the detailed mechanisms of inflammatory responses and organ damage. Various environmental factors, pathogens, and toxicants, including ultraviolet light, drugs, viral pathogens, gut microbiome metabolites, and sex hormones trigger the onset of SLE pathogenesis in genetically susceptible individuals and result in the disruption of immune homeostasis of cytokines, macrophages, T cells, and B cells. Diagnosis and clinical investigations of SLE remain challenging due to its clinical heterogeneity and hitherto only a few approved antimalarials, glucocorticoids, immunosuppressants, and some nonsteroidal anti-inflammatory drugs (NSAIDs) are available for treatment. However, the adverse effects of renal and neuropsychiatric lupus and late diagnosis make therapy challenging. Additionally, SLE is also linked to an increased risk of cardiovascular diseases due to inflammatory responses and the risk of infection from immunosuppressive treatment. Due to the diversity of symptoms and treatment-resistant diseases, SLE management remains a challenging issue. Nevertheless, the use of next-generation therapeutics with stem cell and gene therapy may bring better outcomes to SLE treatment in the future. This review highlights the autoimmune responses as well as potential therapeutic interventions for SLE particularly focusing on the recent therapeutic advancements and challenges.

Sex differences in inflammation during atherosclerosis

Atherosclerosis is the leading cause of death in the United States and worldwide, yet more men die from atherosclerosis than women, and at a younger age. Women, on the other hand, mainly develop atherosclerosis following menopause, and particularly if they have one or more autoimmune diseases, suggesting that the immune mechanisms that increase disease in men are different from those in women. The key processes in the pathogenesis of atherosclerosis are vascular inflammation, lipid accumulation, intimal thickening and fibrosis, remodeling, and plaque rupture or erosion leading to myocardial infarction and ischemia. Evidence indicates that sex hormones alter the immune response during atherosclerosis, resulting in different disease phenotypes according to sex. Women, for example, respond to infection and damage with increased antibody and autoantibody responses, while men have elevated innate immune activation. This review describes current knowledge regarding sex differences in the inflammatory immune response during atherosclerosis. Understanding sex differences is critical for improving individualized medicine.

Attenuation of early atherosclerotic lesions by immunotolerance with β2 glycoprotein I and the immunomodulatory effectors interleukin 2 and 10 in a murine model

OBJECTIVE

This study assessed the effect of cellular and humoral autoimmune response inhibition after immunization with β2-glycoprotein I (β2-GPI) and the effect of immunomodulation with interleukin (IL)-2 and IL-10 in the development of early atherosclerotic vascular lesion in a murine model. Atherosclerosis is increasingly considered a chronic inflammatory disease with pathogenic autoimmune processes. Regulatory T cells, and their cytokines, have been implicated in the inhibition of the development of atherosclerotic lesions and involved in the immunologic tolerance induction.

METHODS

Eight-week-old male C57BL6 LDL-receptor deficient (LDLR(-/-)) mice were fed a cholesterol-rich (2.8%), high-saturated-fat (82%) diet for a week and divided in five groups. The groups received the following intravenous immunizations: group I (control group): one dose of 5 μg β2-GPI; group II: 5 μg β2-GPI I and 1 μg IL-2; group III: 5 μg β2-GPI and 0.75 μg of IL-10; and group IV: 5 μg β2-GPI, 1 μg IL-2, and 0.75 μg IL-10. The aortas of the mice were assessed 8 weeks after inoculation to determine the aortic lesion size and composition in all groups.

RESULTS

β2-GPI immunization attenuated the early atherosclerotic lesions development compared with the control group (P = .001). Macroscopic and histologic aortic atherosclerotic lesions were significantly decreased in the IL-2 and IL-10-treated groups in β2-GPI-tolerant mice compared with the β2-GPI-tolerant group without cytokine injection (P = .001). The association of both cytokines did not provoke a major inhibition in the atherosclerosis development when compared with groups injected with the two cytokines separately.

CONCLUSIONS

The immunotolerance induction against β2-GPI attenuates the development of atherosclerosis lesions in an animal model, enhanced by downregulation of the cellular and humoral autoimmune response provoked by IL-2 and IL-10.

Chronic exposure to oral pathogens and autoimmune reactivity in acute coronary atherothrombosis

Background. It has been hypothesized that various infective agents may activate immune reactions as part of the atherosclerotic process. We aimed to investigate the interrelationship between chronic exposure to oral pathogens and immune-inflammatory response in patients with acute coronary atherothrombosis. Patients and Methods. The study included 200 participants from Serbia: 100 patients with acute myocardial infarction (MI), and 100 age- and sex-matched controls. Antibodies to oral anaerobes and aerobes were determined as well as autoantibodies to endothelial cells, beta-2 glycoprotein I, platelet glycoprotein IIb/IIIa and anticardiolipin. Interleukin-6 (IL-6) and C-reactive protein (CRP) were measured. Results. The mean serum antibodies to oral anaerobes tended to be higher among subjects with MI (0.876 ± 0.303 versus 0.685 ± 0.172 OD, P < 0.001). Similarly, antibody levels against oral aerobes in patients were significantly different from controls. Antibodies against endothelial cell, beta-2 glycoprotein I, platelet glycoprotein IIb/IIIa, anticardiolipin along with CRP and IL-6 were highly elevated in patients. The levels of antibodies to oral bacteria showed linear correlation with tissue antibodies, CRP and IL-6. Conclusion. Antibody response to chronic oral bacterial infections and host immune response against them may be responsible for the elevation of tissue antibodies and biomarkers of inflammation which are involved in acute coronary thrombosis development.

Autoimmune heart disease: role of sex hormones and autoantibodies in disease pathogenesis

Cardiovascular disease (CVD) and autoimmune diseases (ADs) are the first and third highest causes of death in the USA, respectively. Men have an increased incidence of the majority of CVDs, including atherosclerosis, myocarditis, dilated cardiomyopathy and heart failure. By contrast, nearly 80% of all ADs occur in women. However, in one category of ADs, rheumatic diseases, CVD is the main cause of death. Factors that link rheumatic ADs to CVD are inflammation and the presence of autoantibodies. In this review we will examine recent findings regarding sex differences in the immunopathogenesis of CVD and ADs, explore possible reasons for the increased occurrence of CVD within rheumatic ADs and discuss whether autoantibodies, including rheumatoid factor, could be involved in disease pathogenesis.

Non-Fas(CD95/APO1)-mediated apoptosis of activated T cells inhibits the development of atherosclerosis

Atherosclerosis is a chronic systemic inflammatory disease. The innate and adaptive immune response might be involved in atherogenesis. Methotrexate (MTX) induces apoptosis of activated T cells by a CD95-independent pathway. The aim of this study was to analyse the effect of immunomodulation by MTX in the development of early atherosclerotic vascular lesions in an animal model. Four-week old male C57BL6 LDL-receptor-deficient mice were fed a diet rich in saturated fat (82%) and cholesterol (2.8%). Thirty animals were given a weekly intramuscular injection of MTX, establishing three subgroups: 10, 30 and 50 mg/kg. Ten further mice were used as an immunocompetent control group. Aortic thickening was significantly inhibited in all MTX-treated groups compared with the control group at 30 days (0.46 ± 0.003 mm(2) in the control group vs 0.31 ± 0.002, 0.14 ± 0.009 and 0.16 ± 0.006 mm(2) in the low-, intermediate- and high-dose group, respectively; P = 0.01) and at 60 days. The aortic lumen/total area ratio was also increased in the MTX-treated groups (0.82 ± 0.06 in the control group vs 0.88 ± 0.07, 0.86 ± 0.05 and 0.88 ± 0.04, respectively; P = 0.02). Immunosuppression by MTX inhibits the development of atherosclerotic lesions in arterial vessels in mice, which highlights the crucial role of the immune system in atherogenesis.

The relation between atherosclerosis and the occurrence of postoperative delirium in vascular surgery patients

Old and frail patients undergoing vascular surgery seem at great risk of developing postoperative delirium (POD). The aim of this review was to identify risk factors for the development of POD in vascular surgery patients. Different aetiological factors have been identified, such as increased age, excessive blood transfusion, preoperative cognitive impairment and depression. Mounting evidence supports a role for inflammation and tobacco exposure in the development of POD. Vascular surgery patients differ from the general surgical population because they suffer from both loco-regional and systemic atherosclerosis. Although current scientific evidence cannot fully link both entities, evidence is growing that suggests a relationship between systemic and cerebrovascular atherosclerosis and the development of POD.

The potential role of preventing atherosclerosis by induction of neonatal tolerance to VLDL

Induction of immune tolerance to ox-LDL could reduce atherosclerosis by modulation immune response. We suppose that very low density lipoprotein (VLDL) may have a similar role to ox-LDL in autoimmune response of atherosclerosis. In this study, neonatal rats were injected with ox-LDL, VLDL, or equal-volume saline, respectively. Vaccination with ox-LDL reduced the level of specific antibody, T cells proliferation response, and the level of endothelins. The method also had a tendency of reducing blood lipids. Vaccination with VLDL obviously reduced the level of specific antibody and T cells proliferation. Though there was also a tendency of reducing blood lipids and endothelins, the effect was less prominent than that with ox-LDL. We conclude that, although the effect was less obvious, vaccination with VLDL to induce neonatal tolerance had an effect on modulating immune response, protecting endothelial cells, and reducing blood lipids.

The effect of balneotherapy on antioxidant, inflammatory, and metabolic indices in patients with cardiovascular risk factors (hypertension and obesity)--a randomised, controlled, follow-up study

INTRODUCTION

The primary objective of our study was to explore the changes of antioxidant, inflammatory, and metabolic parameters in obese and hypertension people patients during balneotherapy and to evaluate the safety of balneotherapy in these participants.

METHODS

Following randomisation, 22 obese and 20 hypertensive patients underwent balneotherapy with thermal water of 38°C temperature, in 15 sessions of 30 minutes. An additional 22 obese and 20 hypertensive patients served as controls. Antioxidant, inflammatory, and metabolic parameters were determined at baseline, as well as post-treatment and at the end of follow-up (at 15 weeks).

RESULTS

As regards changes observed in hypertensive patients subjected to balneotherapy, differences could be detected between baseline and post-treatment albumin and haemoglobin A(1c) levels only; however, these were no longer significant after 3 months. Although the difference between transferrin levels determined at the end of balneotherapy and 3 months later was significant, it remained within the physiological range, as well as it was accompanied by normal serum iron level and therefore, it was considered irrelevant. C-reactive protein levels of balneotherapy patients decreased significantly after treatment. In obese patients, haemoglobin A(1c) level decreased after balneotherapy, but this difference was not observed either after 3 months. Similarly, both transferrin and C-reactive protein levels changed from baseline, but not between groups.

CONCLUSIONS

This study contributes important information regarding the safety of balneotherapy in hypertensive and obese diabetics by showing no alterations of antioxidant, inflammatory, or metabolic indices. The findings of this study confirm that balneotherapy is not contraindicated for hypertensive or obese patients.