Unlocking unknown mutations to understand causal relationships in cardiovascular science: paving the path to personalized cardiovascular care

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Multiple disorders are characterized by dysregulated inflammation, many of which entail genetic background. Genome-wide sequencing has provided the means to define the molecular basis of examples that may be rare or even unique. Importantly, such genetically determined autoinflammatory disorders provide proof of principle of molecular pathways in humans and may point the way to treating more common inflammatory conditions. Recent research has shed light on a previously unrecognized autoinflammatory condition arising from a mutation in the interleukin-1 receptor 1 (IL-1R1) gene, termed ‘Loss of IL-1R1 Sensitivity to IL-1Ra’ (LIRSA). This novel discovery, highlighted in the study by Wang et al. published in Immunity,1 offers crucial insights into the pathophysiology of autoinflammatory conditions and unveils promising avenues for targeted therapy (Figure 1). The image showcases the molecular normal condition, the efficacy of canakinumab, and the development of a novel drug, Rilabnacept. (A) The authors designated the condition as Loss of IL-1R1 Sensitivity to IL-1Ra (LIRSA). The patient with LIRSA responded well to canakinumab, indicating hyperactivation of the IL-1β pathway due to a defect in IL-1Ra inhibition as the cause of bone and systemic inflammation. (B) The authors show that one allele of mutant IL-1R1 is sufficient to cause constitutive activation of the IL-1β pathway. Elevated IL-1Ra levels in IL-1-mediated diseases highlight the need to minimize IL-1Ra neutralization for improved efficacy of IL-1 Trap. (C) The authors developed a new IL-1 Trap, Rilabnacept, targeting IL-1α and IL-1β without interfering with endogenous IL-1Ra. Adapted from Wang et al.1 The authors found that a genetic mutation associated with LIRSA involves the substitution of a basic, polar amino acid at residue 131 with an acidic amino acid (p.Lys131Glu) within the IL-1R1 protein. Functionally, this genetic alteration disrupts the normal interaction between IL-1R1 and its regulatory counterpart, IL-1Ra, critical for controlling the IL-1 signalling pathways. In detail, IL-1Ra is a secreted anti-inflammatory cytokine which competes with active IL-1 and blocks binding to their common activating receptor, IL-1R1. IL-1R1 plays a pivotal role as a cell surface receptor, mediating the biological effects of IL-1α and IL-1β, essential cytokines that regulate numerous immune and inflammatory responses.2 The disruption caused by the p.Lys131Glu mutation impairs the inhibitory function of IL-1Ra, leading to uncontrolled activation in response to IL-1α or IL-1β stimulation. This mutation manifests in mice as systemic inflammation, corroborating the clinical symptoms observed in patients diagnosed with LIRSA. The study’s foundation lies in a patient with a previously diagnosed inflammatory disorder, who exhibited marked clinical improvement in response to canakinumab, a monoclonal antibody targeting IL-1β. Canakinumab treatment resulted in rapid alleviation of pain, improved physical performance, reduced inflammatory markers, and enhanced bone health. This case emphasizes the pivotal role of IL-1β in driving the pathogenesis of autoinflammatory disorders and, particularly, in disrupting bone homeostasis. The study’s implications extend beyond the scope of autoinflammatory disorders and into the realm of cardiovascular research. The cytokine IL-1β, a pivotal player in autoinflammatory diseases, has been implicated in cardiovascular pathologies.3 Chronic inflammation, particularly driven by IL-1β, contributes significantly to the progression of cardiovascular diseases.4 Notably, IL-1β has been implicated in atherosclerosis, where IL-1 signalling plays a crucial role in the inflammatory process underlying this condition. The findings in this study highlight the potential for IL-1-targeted therapies, like canakinumab and the proposed modified IL-1Trap, termed Rilabnacept, in mitigating cardiovascular risk associated with chronic inflammation. The Canakinumab Anti-inflammatory Thrombosis Outcomes Study (CANTOS5) presented evidence showing that blocking IL-1β reduced cardiovascular events among patients with a prior history of myocardial infarction and raised C-reactive protein levels. However, the development of Rilabnacept opens a further avenue for managing cardiovascular diseases by targeting IL-1α as well as IL-1β without disrupting the regulatory function of IL-1Ra. The insights garnered from the study’s molecular mechanisms provide a foundation for novel therapeutic interventions in these conditions, potentially broadening the scope of cardiovascular disease management, potentially at early stages aiming at prevention. In this context, further studies assessing its socioeconomic feasibility will need to be performed, given the low cost of other innovations in the field, such as colchicine.6 In addition to targeted therapies, broad-spectrum anti-inflammatory agents like colchicine have been investigated for their potential to reduce cardiovascular events. Colchicine is currently an FDA-approved drug against atherosclerotic cardiovascular disease because of its anti-inflammatory properties that make it a candidate for preventing cardiovascular events. Studies such as the Colchicine Cardiovascular Outcomes Trial have shown that colchicine can reduce the risk of recurrent cardiovascular events by modulating inflammatory pathways. Additionally, the Cardiovascular Inflammation Reduction Trial (CIRT) aimed to evaluate whether low-dose methotrexate, an anti-inflammatory agent commonly used in rheumatoid arthritis, could reduce cardiovascular events in patients with a history of myocardial infarction or multivessel coronary artery disease and either type 2 diabetes or metabolic syndrome. However, CIRT did not show a reduction in cardiovascular events, highlighting the complexity of inflammation pathways and the need for more targeted approaches like those involving IL-1β inhibition. While broad-spectrum anti-inflammatory agents like colchicine offer promising avenues due to their broad action and affordability, targeted therapies based on genetic and inflammatory profiles, as highlighted by the differences between CIRT and CANTOS, may provide more effective and personalized treatment options in the future. The present study’s elucidation of a novel functional IL-1R1 mutation and its impact on the IL-1 signalling pathway has implications for autoimmune and inflammatory conditions beyond autoinflammatory disorders. IL-1R1 polymorphisms have been linked to several inflammatory diseases, including rheumatoid arthritis, Crohn’s disease, and psoriasis. The study underscores the critical role of IL-1 in inflammatory bone diseases, such as chronic recurrent multifocal osteomyelitis (CRMO7). The identified IL-1R1 mutation resulting in LIRSA has provided valuable insights into the mechanisms of bone inflammation. To design more effective clinical trials for cardiovascular outcomes, a genetic approach can be instrumental. Identifying genetic markers and inflammatory profiles in patients allows for more precise targeting of therapies. For example, selecting patients with specific genetic mutations or elevated levels of particular inflammatory cytokines can help tailor treatments that are more likely to be effective. This precision medicine approach could improve the success rates of clinical trials and lead to more personalized and effective treatments for cardiovascular diseases and other inflammatory conditions. Overall, while this study focuses on a single patient and would ideally need further validation in larger cohorts, the comprehensive elucidation of the genetic basis of LIRSA opens new avenues for precision medicine. Identifying specific genetic mutations and tailoring treatments accordingly holds potential not only for patients with LIRSA but also for other IL-1-driven autoinflammatory disorders and the associated cardiovascular implications. In conclusion, the study by Wang et al. marks a sig

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