Selective apheresis of C-reactive protein: a new therapeutic option in myocardial infarction?

C-Reactive Protein: An Important Inflammatory Marker of Coronary Atherosclerotic Disease

Cardiovascular disease (CVD) is the most common cause of death worldwide, with coronary atherosclerotic heart disease (CHD) accounting for the majority of events. Evidence demonstrates that inflammation plays a vital role in the development of CHD. The association between C-reactive protein (CRP), a representative inflammatory biomarker, and atherosclerosis (AS), CHD, and inflammation has attracted attention. Therefore, we conducted an extensive search on PubMed using the aforementioned terms as search criteria and identified a total of 1246 articles published from January 2000 to April 2024. Both review and research-based articles consistently indicate CRP as a risk enhancer for CVD, contributing to the refinement of risk stratification and early identification of apparently healthy at-risk populations. Additionally, CRP reflects disease progression and predicts the prognosis of recurrent cardiovascular events. Anti-inflammatory therapeutic strategies targeting CRP also provide new treatment options for patients. This review focuses on the link between CRP and CHD, highlighting how CRP is involved in the pathological progression of AS and its potential value for clinical applications.

Cardioprotective Strategies After Ischemia-Reperfusion Injury

Acute myocardial infarction (AMI) is associated with high morbidity and mortality worldwide. Although early reperfusion is the most effective strategy to salvage ischemic myocardium, reperfusion injury can develop with the restoration of blood flow. Therefore, it is important to identify protection mechanisms and strategies for the heart after myocardial infarction. Recent studies have shown that multiple intracellular molecules and signaling pathways are involved in cardioprotection. Meanwhile, device-based cardioprotective modalities such as cardiac left ventricular unloading, hypothermia, coronary sinus intervention, supersaturated oxygen (SSO2), and remote ischemic conditioning (RIC) have become important areas of research. Herein, we review the molecular mechanisms of cardioprotection and cardioprotective modalities after ischemia-reperfusion injury (IRI) to identify potential approaches to reduce mortality and improve prognosis in patients with AMI.

Recent advances in the diagnosis and management of acute myocardial infarction

With the discovery of new biomarkers for the early detection of acute myocardial infarction (AMI), advancements in valid medication, and percutaneous coronary intervention (PCI), the overall prognosis of AMI has improved remarkably. Nevertheless, challenges remain which require more difficult work to overcome. Novel diagnostic and therapeutic techniques include new AMI biomarkers, hypothermia therapy, supersaturated oxygen (SSO 2 ) therapy, targeted anti-inflammatory therapy, targeted angiogenesis therapy, and stem cell therapy. With these novel methods, we believe that the infarction size after AMI will decrease, and myocardial injury-associated ventricular remodeling may be avoided. This review focuses on novel advances in the diagnosis and management of AMI.

Being Eaten Alive: How Energy-Deprived Cells Are Disposed of, Mediated by C-Reactive Protein-Including a Treatment Option

In medicine, C-reactive protein (CRP) has become established primarily as a biomarker, predicting patient prognosis in many indications. Recently, however, there has been mounting evidence that it causes inflammatory injury. As early as 1999, CRP was shown to induce cell death after acute myocardial infarction (AMI) in rats and this was found to be dependent on complement. The pathological effect of CRP was subsequently confirmed in further animal species such as rabbit, mouse and pig. A conceptual gap was recently closed when it was demonstrated that ischemia in AMI or ischemia/hypoxia in the severe course of COVID-19 causes a drastic lack of energy in involved cells, resulting in an apoptotic presentation because these cells cannot repair/flip-flop altered lipids. The deprivation of energy leads to extensive expression on the cell membranes of the CRP ligand lysophosphatidylcholine. Upon attachment of CRP to this ligand, the classical complement pathway is triggered leading to the swift elimination of viable cells with the appearance of an apoptotic cell by phagocytes. They are being eaten alive. This, consequently, results in substantial fibrotic remodeling within the involved tissue. Inhibiting this pathomechanism via CRP-targeting therapy has been shown to be beneficial in different indications.

C-reactive protein: a target for therapy to reduce inflammation

C-reactive protein (CRP) is well-recognized as a sensitive biomarker of inflammation. Association of elevations in plasma/serum CRP level with disease state has received considerable attention, even though CRP is not a specific indicator of a single disease state. Circulating CRP levels have been monitored with a varying degree of success to gauge disease severity or to predict disease progression and outcome. Elevations in CRP level have been implicated as a useful marker to identify patients at risk for cardiovascular disease and certain cancers, and to guide therapy in a context-dependent manner. Since even strong associations do not establish causality, the pathogenic role of CRP has often been over-interpreted. CRP functions as an important modulator of host defense against bacterial infection, tissue injury and autoimmunity. CRP exists in conformationally distinct forms, which exhibit distinct functional properties and help explaining the diverse, often contradictory effects attributed to CRP. In particular, dissociation of native pentameric CRP into its subunits, monomeric CRP, unmasks "hidden" pro-inflammatory activities in pentameric CRP. Here, we review recent advances in CRP targeting strategies, therapeutic lowering of circulating CRP level and development of CRP antagonists, and a conformation change inhibitor in particular. We will also discuss their therapeutic potential in mitigating the deleterious actions attributed to CRP under various pathologies, including cardiovascular, pulmonary and autoimmune diseases and cancer.

C-reactive protein and uric acid roles in distinguishing ST-segment elevation myocardial infarction from non-ST-elevation acute coronary syndrome

Acute coronary syndrome (ACS) is defined as a range of conditions which the blood flow to the heart was reduced or stopped. This disorder is correlated to a systemic inflammatory response and some biochemical factors. Therefore, the aim of this study was investigations of serum C-reactive protein (CRP) and uric acid levels in ST-segment elevation myocardial infarction (STEMI) and non-ST-elevation ACS (NSTE ACS), as common subtypes of ACS. Patients with ACS (n = 140) were assessed with coronary arteriography and divided into STEMI and NSTE ACS groups. The serum levels of hs-CRP and uric acid were investigated using a routine clinical chemistry analyzer. Patients with STEMI showed a significant increase in uric acid level compared to those with NSTE ACS (P < .0001). Other data indicated that hs-CRP level in patients with STEMI was significantly higher than individuals with NSTE ACS (P < .0001). Modeling analysis revealed that the increased levels of acid uric and hs-CRP in patients with STEMI were independent of the effects of age, gender, background diseases, and familial history (P < .001). The current study provides further evidence to indicate that hs-CRP and uric acid may be considered as biofactors for comparing STEMI from NSTE ACS and determining disease outcome.

Therapeutic hypothermia can cause non-infective C-reactive protein elevating

Objective

To analyze the relationship between therapeutic hypothermia (TH) and whole blood high-sensitivity C-reactive protein (hs-CRP) in neonates with hypoxic-ischemic encephalopathy (HIE).

Method

Retrospective analysis was made on the clinical data of hospitalized infants diagnosed with asphyxia in our neonatal intensive care unit from January 2014 to June 2021. According to whether TH was performed, they were divided into two groups, the control group (missed the time in other hospitals and did not receive TH) and the treatment group (TH group). In their first ten days, analysis was made on the hs-CRP, white blood cell (WBC) count, neutrophil percentage, platelet count (PLT), and brain MRI. The correlation analysis was carried out based on the severity of brain injury displayed by the brain MRI and the time of hs-CRP elevation to summarize the relationship between TH and the time of hs-CRP elevation and the severity of HIE.

Results

83 infants were included, 28 in the control group and 55 in the TH group. After birth, 33 infants (60.0%) in the TH group and 2 patients (7.1%) in the control group had elevated hs-CRP, which was statistically significant (P < 0.05). The time window for CRP elevation after TH was 72-96 h after the end of treatment; The results of the brain MRI showed 23 in the TH group and 11in the control group with moderate and severe HIE. 21 infants (all in the TH group) had elevated hs-CRP. MRI showed that the number of infants with mild injury or regular infants whose hs-CRP raised in the TH group was 12, and the rate of hs-CRP elevation was 37.5%; in the control group, the rate was 11.8%. The difference was significant. TH can decrease PLT and WBC, but no significance in the two groups. Blood and sputum cultures were negative in all infants, and there were no signs of infection.

Conclusions

TH can increase the blood hs-CRP of HIE neonates, and the probability of its occurrence is related to the severity of HIE. The heavier the HIE, the higher the risk of hs-CRP elevation after TH; The hs-CRP elevation has little to do with infection, and it doesn't recommend using antibiotics actively.

A novel phosphocholine-mimetic inhibits a pro-inflammatory conformational change in C-reactive protein

C-reactive protein (CRP) is an early-stage acute phase protein and highly upregulated in response to inflammatory reactions. We recently identified a novel mechanism that leads to a conformational change from the native, functionally relatively inert, pentameric CRP (pCRP) structure to a pentameric CRP intermediate (pCRP*) and ultimately to the monomeric CRP (mCRP) form, both exhibiting highly pro-inflammatory effects. This transition in the inflammatory profile of CRP is mediated by binding of pCRP to activated/damaged cell membranes via exposed phosphocholine lipid head groups. We designed a tool compound as a low molecular weight CRP inhibitor using the structure of phosphocholine as a template. X-ray crystallography revealed specific binding to the phosphocholine binding pockets of pCRP. We provide in vitro and in vivo proof-of-concept data demonstrating that the low molecular weight tool compound inhibits CRP-driven exacerbation of local inflammatory responses, while potentially preserving pathogen-defense functions of CRP. The inhibition of the conformational change generating pro-inflammatory CRP isoforms via phosphocholine-mimicking compounds represents a promising, potentially broadly applicable anti-inflammatory therapy.

Novel therapeutic strategies to reduce reperfusion injury after acute myocardial infarction

For almost 30 years, urgent revascularization termed primary percutaneous coronary intervention (pPCI) has been a cornerstone of modern care for acute myocardial infarction (AMI). It lowers mortality and improved cardiovascular outcome compared to conservative therapy including thrombolysis. Reperfusion injury, which occurs after successful re-opening of the formerly occluded coronary artery, had been exploited as a potential therapeutic target. When revascularisation became faster and pPCI was successfully performed within 60-90 minutes of symptom onset, the interest in a potential additive effect of targeting reperfusion injury vanished. More recently, several meta-analyses indicated that limiting reperfusion injury prevents microvascular obstruction and reduces final infarct size, thereby lowering the probability of heart failure events and improving quality of life in AMI survivors. Here, we describe the current strategies to limit reperfusion injury and to improve post-AMI outcomes such as systemic or intracoronary hypothermia, left-ventricular unloading, intracoronary infusion of super-saturated oxygen, intermittent coronary sinus occlusion, and C-reactive protein apharesis.

[CRP apheresis in acute myocardial infarction and COVID-19]

C‑reactive protein (CRP) is the best-known acute phase protein. In humans, inflammation and infection are usually accompanied by an increase in CRP levels in the blood, which is why CRP is an important biomarker in daily clinical routine. CRP can mediate the initiation of phagocytosis by labeling damaged cells. This labeling leads to activation of the classical complement pathway (up to C4) and ends in the elimination of pathogens or reversibly damaged or dead cells. This seems to make sense in case of an external wound of the body. However, in the case of "internal wounds" (e.g., myocardial infarction, stroke), CRP induces tissue damage to potentially regenerable tissue by cell labeling, which has corresponding deleterious effects on cardiac and brain tissue or function. The described labeling of ischemic but potentially regenerable cells by CRP apparently also occurs in coronavirus disease 2019 (COVID-19). Parts of the lung become ischemic due to intra-alveolar edema and hemorrhage, and this is accompanied by a dramatic increase in CRP. Use of selective immunoadsorption of CRP from blood plasma ("CRP apheresis") to rapidly and efficiently lower the fulminant CRP load in the body fills this pharmacotherapeutic gap. With CRP apheresis, it is possible for the first time to remove this pathological molecule quickly and efficiently in clinical practice.

Seven COVID-19 Patients Treated with C-Reactive Protein (CRP) Apheresis

Background: The fulminant course of COVID-19, triggered by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), presents with a high mortality rate and still lacks a causative treatment. C-reactive protein (CRP) has been shown to increase dramatically during the disease progression and correlates with deleterious outcomes. Selective CRP apheresis can reduce circulating CRP levels fast and effective. Methods: Seven hospitalized patients with documented severe COVID-19 progression, elevated CRP plasma levels (>100 mg/L) and signs of respiratory failure were treated with CRP apheresis. Two to twelve CRP apheresis sessions were performed generally in 24 h time intervals and depending on CRP plasma levels. Results: All patients had comorbidities. CRP apheresis reduced CRP plasma levels by up to 84% within a few hours, without exhibiting side effects in any patient. Despite signs of severe lung infiltration in all patients, only one patient died. The other patients showed improvements within the chest X-ray after CRP apheresis and were able to recover regardless of intubation and/or ECMO (4 patients). All remaining six patients were discharged from the hospital in good clinical condition. Conclusions: This case series presents a mortality rate of only 14%, which is dramatically lower than expected from the presented CRP levels as well as comorbidities and ventilation requirements. Our clinical observations regarding the here presented seven patients support the hypothesis that CRP is a candidate to be therapeutically targeted in the early stage of severe COVID-19.

Targeting C-Reactive Protein by Selective Apheresis in Humans: Pros and Cons

C-reactive protein (CRP), the prototype human acute phase protein, may be causally involved in various human diseases. As CRP has appeared much earlier in evolution than antibodies and nonetheless partly utilizes the same biological structures, it is likely that CRP has been the first antibody-like molecule in the evolution of the immune system. Like antibodies, CRP may cause autoimmune reactions in a variety of human pathologies. Consequently, therapeutic targeting of CRP may be of utmost interest in human medicine. Over the past two decades, however, pharmacological targeting of CRP has turned out to be extremely difficult. Currently, the easiest, most effective and clinically safest method to target CRP in humans may be the specific extracorporeal removal of CRP by selective apheresis. The latter has recently shown promising therapeutic effects, especially in acute myocardial infarction and COVID-19 pneumonia. This review summarizes the pros and cons of applying this novel technology to patients suffering from various diseases, with a focus on its use in cardiovascular medicine.

Cardiac Glycosides Lower C-Reactive Protein Plasma Levels in Patients with Decompensated Heart Failure: Results from the Single-Center C-Reactive Protein-Digoxin Observational Study (C-DOS)

Recent randomized controlled multi-center trials JUPITER, CANTOS and COLCOT impressively demonstrated the effect of anti-inflammatory therapy on secondary prevention of cardiovascular events. These studies also rapidly re-vitalized the question of whether the C-reactive protein (CRP), the prototype human acute phase protein, is actively involved in atherosclerosis and its sequelae. Direct CRP inhibition may indeed improve the specificity and effectiveness of anti-inflammatory intervention. In the present paper, we report on the final results of our single-center C-reactive protein-Digoxin Observational Study (C-DOS). Methods and Results: Based on the experimental finding that cardiac glycosides potently inhibit hepatic CRP synthesis on the transcriptional level in vitro, 60 patients with decompensated heart failure, NYHA III−IV, severely reduced Left Ventricular Ejection Fraction (LVEF < 40%), and elevated CRP plasma levels were treated by either digoxin + conventional heart failure therapy (30 patients) or by conventional heart failure therapy alone (30 patients). Plasma CRP levels in both groups were assessed for 21 d. Plasma CRP levels on d1, d3 and d21 were compared by regression analysis. CRP levels d21−d1 significantly declined in both groups. Notably, comparative CRP reduction d21−d3 in digoxin versus the control group also revealed borderline significance (p = 0.051). Conclusions: This small observational trial provides the first piece of evidence that cardiac glycosides may inhibit CRP synthesis in humans. In case of further pharmacological developments, cardiac glycosides may emerge as lead compounds for chemical modification in order to improve the potency, selectivity and pharmacokinetics of CRP synthesis inhibition in cardiovascular disease.

The predictive role of early CRP values for one-year mortality in the first two days after acute myocardial infarction

BACKGROUND

An excessive inflammatory reaction after acute myocardial infarction (AMI) is known to be harmful. New anti-inflammatory therapies are required.

PURPOSE

This study assessed the predictive role of early CRP in patients with STEMI.

METHODS

1003 patients with STEMI were analyzed. 180 patients with proven infection were excluded. CRP after 12 h, 24 h, and 48 h after pain onset were evaluated.

RESULTS

Of 823 patients, 103 (12.5%) died within one year after AMI. The deceased patients showed higher CRP, even after already 12 h (6 vs. 13 mg/l, p < 0.001), 24 h (13 vs. 25 mg/l, p < 0.001) and after 48 h (40 vs. 92 mg/l, p < 0.001). A CRP of ≥8 mg/l, 12 h after AMI, was found in 45% and was independently associated with long-term mortality (OR: 2.7, p = 0.03), after 24 h: CRP ≥18 mg/l in 44% (OR: 2.5, p = 0.03), after 48 h: CRP ≥53 mg/l in 44% (OR 1.9, p = 0.03). Early CRP values correlated strongly with the later maximum value of CRP (p < 0.001).

CONCLUSIONS

Already early CRP values are accurate for risk-prediction following AMI. By identifying patients who are beginning to develop an excessive inflammatory response, it may be possible to identify those who benefit from anti-inflammatory therapies.

Myocardial Proteomics Based on Smart Fog Computing and Its Application in Sports

How to strengthen physical fitness to improve the effect and efficiency of sports is an important research direction worthy of research. In response to these problems and limitations, Smart Fog Computing technology is introduced in this paper. Taking rats as the research object, the effective quantitative analysis and research of aerobic exercise on myocardial proteome are achieved through combining the business scope of myocardial proteomics, and connecting corresponding continuous aerobic exercises, verified by simulation analysis. The simulation research results show that the smart fog calculation is effective. For moderate-intensity aerobic exercise, the expression and intensity of the corresponding myocardial protein are changed significantly, and the corresponding heart becomes larger; meanwhile, moderate aerobic exercise can improve the metabolism and enhance digestive ability.

A Sorbent with Synthetic Ligand for Removing Pro-atherogenic and Pro-inflammatory Components from Human Blood Plasma

Elevated levels of apoB-100 containing lipoproteins and markers of systemic inflammation are often observed in patients with cardiovascular diseases. The concentrations can be reduced by pharmacotherapy or extracorporeal treatment. The sorbent, which removes CRP and atherogenic lipoproteins, simultaneously reduces the bloodstream concentration of these components. The efficacy and selectivity of the designed sorbent were studied, desorption constants of CRP (Kd = 4.2 × 10-8 M) and LDL (Kd = 7.7 × 10-7 M) were distribution coefficients of CRP (Kc = 101) and Lp(a) (Kc = 38) were calculated, and the ability to bind large amounts of atherogenic lipoproteins (up to 32 mg of TC per mL of the sorbent gel) was demonstrated. Our sorbent can be recommended for performing complex removal of CRP and atherogenic lipoproteins from the blood plasma in patients with refractory hyperlipidemia and CVD that are accompanied by elevated levels of CRP.

Case Report: C-Reactive Protein Apheresis in a Patient With COVID-19 and Fulminant CRP Increase

Background

Plasma levels of C-reactive protein (CRP), induced by Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) triggering COVID-19, can rise surprisingly high. The increase of the CRP concentration as well as a certain threshold concentration of CRP are indicative of clinical deterioration to artificial ventilation. In COVID-19, virus-induced lung injury and the subsequent massive onset of inflammation often drives pulmonary fibrosis. Fibrosis of the lung usually proceeds as sequela to a severe course of COVID-19 and its consequences only show months later. CRP-mediated complement- and macrophage activation is suspected to be the main driver of pulmonary fibrosis and subsequent organ failure in COVID-19. Recently, CRP apheresis was introduced to selectively remove CRP from human blood plasma.

Case Report

A 53-year-old, SARS-CoV-2 positive, male patient with the risk factor diabetes type 2 was referred with dyspnea, fever and fulminant increase of CRP. The patient's lungs already showed a pattern enhancement as an early sign of incipient pneumonia. The oxygen saturation of the blood was ≤ 89%. CRP apheresis using the selective CRP adsorber (PentraSorb® CRP) was started immediately. CRP apheresis was performed via peripheral venous access on 4 successive days. CRP concentrations before CRP apheresis ranged from 47 to 133 mg/l. The removal of CRP was very effective with up to 79% depletion within one apheresis session and 1.2 to 2.14 plasma volumes were processed in each session. No apheresis-associated side effects were observed. It was at no point necessary to transfer the patient to the Intensive Care Unit or to intubate him due to respiratory failure. 10 days after the first positive SARS-CoV-2 test, CRP levels stayed below 20 mg/l and the patient no longer exhibited fever. Fourteen days after the first positive SARS-CoV-2 test, the lungs showed no sign of pneumonia on X-ray.

Conclusion

This is the first report on CRP apheresis in an early COVID-19 patient with fulminant CRP increase. Despite a poor prognosis due to his diabetes and biomarker profile, the patient was not ventilated, and the onset of pneumonia was reverted.

C-reactive protein velocity predicts microvascular pathology after acute ST-elevation myocardial infarction

BACKGROUND

The role of C-reactive protein velocity (CRPv) as an early and sensitive marker of an excessive inflammatory response in the setting of acute ST-elevation myocardial infarction (STEMI) is only poorly understood. The aim of this study was to investigate, in patients with STEMI treated with primary percutaneous coronary intervention (PCI), the association of CRPv with microvascular infarct pathology.

METHODS AND RESULTS

This prospective cohort study included a total of 316 patients with STEMI undergoing PCI. CRPv was defined as the difference between CRP 24 ± 8 h and CRP at hospital admission, divided by the time (in h) that have passed during the two examinations. The association of biomarker levels with cardiac magnetic resonance (CMR)-determined microvascular obstruction (MVO) was evaluated. CMR was performed at a median of 3 [interquartile range 2-4] days after PCI. After adjustment for cardiac troponin T (cTnT), anterior infarction and TIMI flow pre and post-PCI, CRPv (odds ratio 2.70, 95% confidence interval (CI) 1.54-4.73; p = 0.001) remained significantly associated with the occurrence of MVO. CRPv (area under the curve [AUC] 0.76, 95% CI 0.71-0.81; p < 0.001) was a better predictor for MVO compared to 24 h CRP (AUC difference: 0.03, p = 0.002). The addition of CRPv to peak cTnT resulted in a higher AUC for MVO prediction than peak cTnT alone (AUC 0.86, 95% CI 0.82-0.90; p < 0.001 vs. AUC 0.84, 95% CI 0.79-0.88; p < 0.001. AUC difference: 0.02, p = 0.042).

CONCLUSIONS

In patients with STEMI treated with primary PCI, CRPv was associated with microvascular infarct pathology with a predictive value incremental to cTnT, suggesting CRPv as an early and sensitive biomarker for more severe infarct pathology and outcome.

Inflammation during Percutaneous Coronary Intervention-Prognostic Value, Mechanisms and Therapeutic Targets

Periprocedural myocardial injury and myocardial infarction (MI) are not infrequent complications of percutaneous coronary intervention (PCI) and are associated with greater short- and long-term mortality. There is an abundance of preclinical and observational data demonstrating that high levels of pre-, intra- and post-procedural inflammation are associated with a higher incidence of periprocedural myonecrosis as well as future ischaemic events, heart failure hospitalisations and cardiac-related mortality. Beyond inflammation associated with the underlying coronary pathology, PCI itself elicits an acute inflammatory response. PCI-induced inflammation is driven by a combination of direct endothelial damage, liberation of intra-plaque proinflammatory debris and reperfusion injury. Therefore, anti-inflammatory medications, such as colchicine, may provide a novel means of improving PCI outcomes in both the short- and long-term. This review summarises periprocedural MI epidemiology and pathophysiology, evaluates the prognostic value of pre-, intra- and post-procedural inflammation, dissects the mechanisms involved in the acute inflammatory response to PCI and discusses the potential for periprocedural anti-inflammatory treatment.

Past, Present, and Future of Blood Biomarkers for the Diagnosis of Acute Myocardial Infarction-Promises and Challenges

Despite important advancements in acute myocardial infarction (AMI) management, it continues to represent a leading cause of mortality worldwide. Fast and reliable AMI diagnosis can significantly reduce mortality in this high-risk population. Diagnosis of AMI has relied on biomarker evaluation for more than 50 years. The upturn of high-sensitivity cardiac troponin testing provided extremely sensitive means to detect cardiac myocyte necrosis, but this increased sensitivity came at the cost of a decrease in diagnostic specificity. In addition, although cardiac troponins increase relatively early after the onset of AMI, they still leave a time gap between the onset of myocardial ischemia and our ability to detect it, thus precluding very early management of AMI. Newer biomarkers detected in processes such as inflammation, neurohormonal activation, or myocardial stress occur much earlier than myocyte necrosis and the diagnostic rise of cardiac troponins, allowing us to expand biomarker research in these areas. Increased understanding of the complex AMI pathophysiology has spurred the search of new biomarkers that could overcome these shortcomings, whereas multi-omic and multi-biomarker approaches promise to be game changers in AMI biomarker assessment. In this review, we discuss the evolution, current application, and emerging blood biomarkers for the diagnosis of AMI; we address their advantages and promises to improve patient care, as well as their challenges, limitations, and technical and diagnostic pitfalls. Questions that remain to be answered and hotspots for future research are also emphasized.

Extracellular vesicles are associated with C-reactive protein in sepsis

There is increasing evidence that C-reactive protein (CRP) can mediate inflammatory reactions following the transformation of functionally inert pentameric CRP (pCRP) into its structural isoform pCRP* and into monomeric CRP (mCRP). This conversion can occur on the membranes of apoptotic or activated cells or on extracellular vesicles (EVs) shed from the cell surface. Here, we characterized the association of CRP with EVs in plasma from sepsis patients using flow cytometry, and found highly elevated levels of total EV counts and CRP⁺ EVs as compared to healthy individuals. We further assessed the ability of PentraSorb CRP, an extracorporeal device for the adsorption of CRP, to deplete free CRP and CRP⁺ EVs. Treatment of septic plasma with the adsorbent in vitro resulted in almost complete removal of both, free CRP and CRP⁺ EVs, while total EV counts remained largely unaffected, indicating the detachment of CRP from the EV surface. EVs from septic plasma elicited a release of interleukin-8 from cultured human monocytes, which was significantly reduced by adsorbent treatment prior to EV isolation. Our findings provide evidence that CRP⁺ EVs exhibit pro-inflammatory characteristics and can contribute to the spreading of inflammation throughout the circulation on top of their pro-coagulant activity.

C-Reactive Protein Apheresis as Anti-inflammatory Therapy in Acute Myocardial Infarction: Results of the CAMI-1 Study

Background: C-reactive protein (CRP) is a well-known marker of inflammation. It is less known that CRP mediates tissue damage in acute myocardial infarction (AMI) thus potentially worsening prognosis. A newly developed specific CRP adsorber allows efficient lowering of CRP levels and may improve survival.

Objectives: Aim of this multi-center, controlled, non-randomized first-in-man CRP apheresis in Acute Myocardial Infarction study (CAMI-1) was to investigate the relationship between CRP levels (CRP gradient), myocardial infarct size and function as well as safety and efficacy of CRP apheresis in the setting of acute ST-segment Elevation Myocardial Infarction (STEMI) in humans.

Methods: Eighty-three patients (45 apheresis, 38 controls) were recruited. CRP apheresis was performed 24 ± 12, 48 ± 12, and optionally 72 ± 12 h after onset of symptoms. First aphereses were performed at a median CRP concentration of 23.0 mg/L (range 9–279). In each apheresis session, 5,900 ± 400 mL plasma was processed via peripheral venous access. Primary study endpoint was a reduction in myocardial infarct size after STEMI as determined by cardiovascular magnetic resonance (CMR).

Results: In controls, the CRP concentration significantly correlated with infarct size (p = 0.002) and decreased myocardial function (p ≤ 0.001). The CRP concentration in apheresis patients did not correlate with infarct size (p = 0.66) or left ventricular (LV) function (p = 0.79) and global strains and therefore significantly differed from controls (p = 0.03 and p = 0.002). Three major adverse cardiac events occurred in the control group after 12 months, none occurred in the apheresis group. Mean CRP depletion achieved over all apheresis procedures was 53.0 ± 15.1%. Apheresis sessions were well-tolerated. Reduced infarct size in the apheresis group compared to the control group (primary endpoint) was not achieved according to the original statistical analysis plan. Taking into account the individual CRP levels, however, revealed significant results. Modifications of the analysis plan were introduced in order to recruit a sufficient number of patients.

Conclusions: This pilot study in humans reveals a correlation between CRP concentration and myocardial infarct size. CRP concentrations in STEMI can effectively be reduced by CRP apheresis without relevant side effects. CRP apheresis has the potential to interfere with deleterious aspects of STEMI. By lowering CRP levels, it resulted in the loss of correlation of CRP concentrations with myocardial infarct sizes as well as LV function. These results encourage a larger, randomized clinical trial.

Clinical Trial Registration:https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00008988, DRKS00008988.

C-Reactive Protein Triggers Cell Death in Ischemic Cells

C-reactive protein (CRP) is the best-known acute phase protein. In humans, almost every type of inflammation is accompanied by an increase of CRP concentration. Until recently, the only known physiological function of CRP was the marking of cells to initiate their phagocytosis. This triggers the classical complement pathway up to C4, which helps to eliminate pathogens and dead cells. However, vital cells with reduced energy supply are also marked, which is useful in the case of a classical external wound because an important substrate for pathogens is disposed of, but is counterproductive at internal wounds (e.g., heart attack or stroke). This mechanism negatively affects clinical outcomes since it is established that CRP levels correlate with the prognosis of these indications. Here, we summarize what we can learn from a clinical study in which CRP was adsorbed from the bloodstream by CRP-apheresis. Recently, it was shown that CRP can have a direct effect on blood pressure in rabbits. This is interesting in regard to patients with high inflammation, as they often become tachycardic and need catecholamines. These two physiological effects of CRP apparently also occur in COVID-19. Parts of the lung become ischemic due to intra-alveolar edema and hemorrhage and in parallel CRP increases dramatically, hence it is assumed that CRP is also involved in this ischemic condition. It is meanwhile considered that most of the damage in COVID-19 is caused by the immune system. The high amounts of CRP could have an additional influence on blood pressure in severe COVID-19.

Prognostic impact of admission high-sensitivity C-reactive protein in acute myocardial infarction patients with and without diabetes mellitus

BACKGROUND

High-sensitivity C-reactive protein (hs-CRP) elevation frequently occurs in acute myocardial infarction (AMI) and is associated with adverse outcomes. Since diabetes mellitus (DM) is characterized by an underlying chronic inflammation, hs-CRP may have a different prognostic power in AMI patients with and without DM.

METHODS

We prospectively included 2064 AMI patients; hs-CRP was measured at hospital admission. Patients were grouped according to hs-CRP quartiles and DM status. The primary endpoint was a composite of in-hospital mortality, cardiogenic shock, and acute pulmonary edema. Two-year all-cause mortality was the secondary endpoint.

RESULTS

Twenty-six percent (n = 548) of patients had DM and they had higher hs-CRP levels than non-DM patients (5.32 vs. 3.24 mg/L; P < 0.0001). The primary endpoint incidence in the overall population (7%, 9%, 13%, 22%; P for trend < 0.0001), in DM (14%, 9%, 21%, 27%; P = 0.0001), and non-DM (5%, 8%, 10%, 19%; P < 0.0001) patients increased in parallel with hs-CRP quartiles. The adjusted risk of the primary endpoint increased in parallel with hs-CRP quartiles in DM and non-DM patients but this relationship was less evident in DM patients. In the overall population, the adjusted OR of the primary endpoint associated with an hs-CRP value ≥ 2 mg/L was 2.10 (95% CI 1.46-3.00). For the same risk, hs-CRP was 7 and 2 mg/L in patients with and without DM. A similar behavior was observed for the secondary endpoint when the HR associated with an hs-CRP value ≥ 2 mg/L found in the overall population was 2.25 (95% CI 1.57-3.22). For the same risk, hs-CRP was 8 and 1.5 mg/L in DM and non-DM patients.

CONCLUSIONS

This study shows that hs-CRP predicts in-hospital outcome and two-year mortality in AMI patients with and without DM. However, in DM patients, the same risk of developing events as in non-DM patients is associated to higher hs-CRP levels.

Early Selective C-Reactive Protein Apheresis in a Patient with Acute ST Segment Elevation Myocardial Reinfarction

The patient was admitted for urgent coronary angiography following an acute anterior ST segment elevation myocardial reinfarction (STEMI) caused by acute stent thrombosis. A stent had been implanted 10 days prior to the reinfarction for an acute anterior STEMI. However, the patient had stopped taking ticagrelor post-discharge. Primary percutaneous coronary intervention of the left anterior descending artery was performed. Subsequently, due to a high C-reactive protein (CRP) level, 3 CRP apheresis sessions were performed, with the first session starting 12 h after the onset of symptoms. A significant drop in CRP was noted after each apheresis. The post-procedural course was uneventful.

Selective Apheresis of C-Reactive Protein for Treatment of Indications with Elevated CRP Concentrations

Almost every kind of inflammation in the human body is accompanied by rising C-reactive protein (CRP) concentrations. This can include bacterial and viral infection, chronic inflammation and so-called sterile inflammation triggered by (internal) acute tissue injury. CRP is part of the ancient humoral immune response and secreted into the circulation by the liver upon respective stimuli. Its main immunological functions are the opsonization of biological particles (bacteria and dead or dying cells) for their clearance by macrophages and the activation of the classical complement pathway. This not only helps to eliminate pathogens and dead cells, which is very useful in any case, but unfortunately also to remove only slightly damaged or inactive human cells that may potentially regenerate with more CRP-free time. CRP action severely aggravates the extent of tissue damage during the acute phase response after an acute injury and therefore negatively affects clinical outcome. CRP is therefore a promising therapeutic target to rescue energy-deprived tissue either caused by ischemic injury (e.g., myocardial infarction and stroke) or by an overcompensating immune reaction occurring in acute inflammation (e.g., pancreatitis) or systemic inflammatory response syndrome (SIRS; e.g., after transplantation or surgery). Selective CRP apheresis can remove circulating CRP safely and efficiently. We explain the pathophysiological reasoning behind therapeutic CRP apheresis and summarize the broad span of indications in which its application could be beneficial with a focus on ischemic stroke as well as the results of this therapeutic approach after myocardial infarction.

First-in-Man: Case Report of Selective C-Reactive Protein Apheresis in a Patient with SARS-CoV-2 Infection

Patient: Male, 72-year-old

Final Diagnosis: SARS-CoV-2

Symptoms: Dyspnea

Medication: Standard

Clinical Procedure: C-reactive protein apheresis

Specialty: Immunology

Evaluating Novel Targets of Ischemia Reperfusion Injury in Pig Models

Coronary heart diseases are of high relevance for health care systems in developed countries regarding patient numbers and costs. Disappointingly, the enormous effort put into the development of innovative therapies and the high numbers of clinical studies conducted are counteracted by the low numbers of therapies that become clinically effective. Evidently, pre-clinical research in its present form does not appear informative of the performance of treatments in the clinic and, even more relevant, it appears that there is hardly any consent about how to improve the predictive capacity of pre-clinical experiments. According to the steadily increasing relevance that pig models have gained in biomedical research in the recent past, we anticipate that research in pigs can be highly predictive for ischemia-reperfusion injury (IRI) therapies as well. Thus, we here describe the significance of pig models in IRI, give an overview about recent developments in evaluating such models by clinically relevant methods and present the latest insight into therapies applied to pigs under IRI.

Selective C-Reactive Protein-Apheresis in Patients

C-reactive protein (CRP), the prototype human acute-phase protein, is a well-known marker of inflammation. However, CRP may also mediate tissue damage in various human diseases like atherosclerosis, acute myocardial infarction, dilated cardiomyopathy, stroke, and potentially autoimmune disease. Therefore, CRP elimination from human plasma may indeed be a widely usable therapeutic approach. Recently, a first-in-man case report of selective CRP-apheresis in a patient with acute ST-segment elevation myocardial infarction (STEMI) has been published. Here, the method is further elucidated by detailed description of 13 patients receiving CRP-apheresis at two study centers. Thirteen patients received two sequential CRP-apheresis treatments with the PentraSorb CRP adsorber starting 24 ± 12 h after STEMI and successful percutaneous coronary intervention (PCI). CRP was measured immediately before and after each treatment, and additionally twice a day for a period of 96 h after symptom onset. Compared to the initial (before-treatment) CRP plasma concentration, CRP-apheresis resulted in an average 53.4% ± 11.9% CRP depletion. First apheresis was performed 27.5 ± 4.6 h after symptom onset at a mean CRP concentration of 25.1 ± 11.1 mg/L. Mean CRP concentration after the first treatment was 12.1 ± 6.4 mg/L. Second apheresis started 47.9 ± 5.4 h after symptom onset at a mean CRP concentration of 30.2 ± 21.4 mg/L. After the second treatment, mean CRP concentration was reduced to 13.9 ± 10.9 mg/L. No severe apheresis-associated side effects were observed. Patients tolerated selective CRP-apheresis without any side effects. The new method is feasible and safe and significantly reduces CRP plasma concentration in humans.

PentraSorb C-Reactive Protein: Characterization of the Selective C-Reactive Protein Adsorber Resin

C-reactive protein (CRP) is well known as a general marker of inflammation. It furthermore represents a reliable risk factor for cardiac events and mediates tissue damage in acute myocardial infarction (AMI). It has been demonstrated that selective CRP depletion by extracorporeal apheresis in a porcine AMI model had beneficial effects on the infarcted area and the cardiac output. We therefore developed a novel adsorber for CRP apheresis from human plasma (PentraSorb CRP). It is intended for use in the clinic as therapy for patients suffering from AMI or other acute inflammatory diseases with elevated CRP plasma levels. The PentraSorb resin specifically bound CRP from human blood plasma and almost no other proteins as determined via Sodium dodecyl sulfate polyacrylamide gel electropheresis (SDS-PAGE). The resin further efficiently and selectively depleted CRP from plasma with low as well as high CRP concentrations (10-100 mg/L) at different flow rates, ranging from 17 to 40 mL/min. The resin was regenerable for up to 200 times without losing its CRP binding capacity or affecting biocompatibility. The depletion of CRP from plasma was comparable between the utilized small-scale column (0.5 mL resin) and the PentraSorb CRP adsorber (20 mL resin volume). The established features can therefore be applied to the clinical setting. In summary, PentraSorb CRP provides a novel, specific, and efficient CRP-binding resin that could be used in apheresis therapy for patients suffering from inflammatory diseases such as AMI, stroke, acute pancreatitis, and Crohn's disease.

"First in Man": Case Report of Selective C-Reactive Protein Apheresis in a Patient with Acute ST Segment Elevation Myocardial Infarction

C-reactive protein (CRP) may be causative in cardiovascular disease. As yet, no specific CRP inhibitor for human application has been described. A 69-year-old male was referred with ST segment elevation myocardial infarction (STEMI). Typical symptoms of chest pain started at 10.00 p.m. The patient was admitted to the hospital at 1.30 a.m. the next day. As ECG showed anterior wall myocardial infarction, the patient was immediately transferred to successful emergency angioplasty/drug-eluting- (DE-) stenting of the subtotally occluded left anterior descending artery. Consecutively, the hemodynamically stable patient was monitored at the chest pain unit. C-reactive protein (CRP) apheresis using the CRP adsorber (PentraSorb® CRP) within CAMI-1 trial was performed 34 h and 58 h after the onset of symptoms. In each apheresis session, 6000 ml plasma was treated via peripheral venous access. Plasma CRP levels decreased from 28.77 mg/l to 12.58 mg/l during the first apheresis session and from 24.17 mg/l to 11.55 mg/l during the second session, respectively. No side effects were observed. This is the first report of selective CRP apheresis in a man. The technology offers multiple opportunities to clarify the immunological/pathogenic role of CRP in health and disease.

The Pentraxins 1975-2018: Serendipity, Diagnostics and Drugs

The phylogenetically ancient, pentraxin family of plasma proteins, comprises C-reactive protein (CRP) and serum amyloid P component (SAP) in humans and the homologous proteins in other species. They are composed of five, identical, non-covalently associated protomers arranged with cyclic pentameric symmetry in a disc-like configuration. Each protomer has a calcium dependent site that mediates the particular specific ligand binding responsible for all the rigorously established functional properties of these proteins. No genetic deficiency of either human CRP or SAP has been reported, nor even any sequence polymorphism in the proteins themselves. Although their actual functions in humans are therefore unknown, gene deletion studies in mice demonstrate that both proteins can contribute to innate immunity. CRP is the classical human acute phase protein, routinely measured in clinical practice worldwide to monitor disease activity. Human SAP, which is not an acute phase protein, is a universal constituent of all human amyloid deposits as a result of its avid specific binding to amyloid fibrils of all types. SAP thereby contributes to amyloid formation and persistence in vivo. Whole body radiolabelled SAP scintigraphy safely and non-invasively localizes and quantifies systemic amyloid deposits, and has transformed understanding of the natural history of amyloidosis and its response to treatment. Human SAP is also a therapeutic target, both in amyloidosis and Alzheimer's disease. Our drug, miridesap, depletes SAP from the blood and the brain and is currently being tested in the DESPIAD clinical trial in Alzheimer's disease. Meanwhile, the obligate therapeutic partnership of miridesap, to deplete circulating SAP, and dezamizumab, a humanized monoclonal anti-SAP antibody that targets residual SAP in amyloid deposits, produces unprecedented removal of amyloid from the tissues and improves organ function. Human CRP binds to dead and damaged cells in vivo and activates complement and this can exacerbate pre-existing tissue damage. The adverse effects of CRP are completely abrogated by compounds that block its binding to autologous ligands and we are developing CRP inhibitor drugs. The present personal and critical perspective on the pentraxins reports, for the first time, the key role of serendipity in our work since 1975. (345 words).

Apheresis to Mitigate Atherosclerotic Vascular Disease

BACKGROUND

Therapeutic apheresis is a term used to describe a group of treatments where blood components are separated in real time, and one component is removed, exchanged, and/or treated to remove pathogenic substances from the circulation. Plasma exchange, which removed all plasma components, and lipid apheresis which selectively removes lipoproteins from circulation, have both been used to treat atherosclerotic vascular diseases.

METHODS

To review the literature regarding the application of therapeutic apheresis for atherosclerotic vascular diseases.

RESULTS

Primarily lipid apheresis is used to treat atherosclerotic vascular diseases, particularly familial hypercholesterolemia, lipoprotein (a) hyperlipoproteinemia and peripheral vascular diseases. Lipid apheresis can be used as first line or second line treatment with a strong evidenced-based recommendation. Its use has decreased atherosclerotic events.

CONCLUSION

Lipid apheresis is an important therapy for the treatment of familial hypercholesterolemia, lipoprotein (a) hyperlipoproteinemia and peripheral vascular diseases. Lipid apheresis does more than remove low-density lipoproteins and other lipoproteins but also decreases inflammatory markers and improves blood flow.

Association of pre-admission statin therapy and the inflammatory response in ST elevation myocardial infarction patients

PURPOSE

To demonstrate the possible association of statin therapy with C reactive protein (CRP) serial measurements in ST elevation myocardial infarction (STEMI) patients.

MATERIALS AND METHODS

STEMI patients between 2008 and 2016 with available CRP data from admission were divided into two groups according to pre-admission statin therapy. A second CRP measurement was noted following primary coronary intervention (within 24 h from admission). The difference between the two measurements was designated ΔCRP.

RESULTS

The cohort consisted of 1134 patients with a median age of 61 (IQR52-70), 81% males. Patients on statins prior to admission (336/1134, 26%) were more likely to have CRP levels within normal range (≤5 mg/l) compared to patients without prior treatment, both at admission (75 vs. 24%, p = 0.004) and at 24 h (70 vs. 48%, p = 0.029). The prevalence of patients with pre-admission statin therapy decreased as ΔCRP increased (p = 0.004; n = 301). The likelihood of ΔCRP to be above 5 mg/l in patients with pre-admission statin therapy was reduced after age and gender adjustments (OR 0.54, 95% CI 0.32-0.92, p = 0.023) and in multivariate (OR 0.57, 95% CI 0.33-0.99, p = 0.048) analysis.

CONCLUSIONS

Pre-admission statin therapy is associated with a less robust inflammatory response in STEMI patients, highlighting statin's pathophysiological importance.

Efferocytosis and Outside-In Signaling by Cardiac Phagocytes. Links to Repair, Cellular Programming, and Intercellular Crosstalk in Heart

Phagocytic sensing and engulfment of dying cells and extracellular bodies initiate an intracellular signaling cascade within the phagocyte that can polarize cellular function and promote communication with neighboring non-phagocytes. Accumulating evidence links phagocytic signaling in the heart to cardiac development, adult myocardial homeostasis, and the resolution of cardiac inflammation of infectious, ischemic, and aging-associated etiology. Phagocytic clearance in the heart may be carried out by professional phagocytes, such as macrophages, and non-professional cells, including myofibrolasts and potentially epithelial cells. During cardiac development, phagocytosis initiates growth cues for early cardiac morphogenesis. In diseases of aging, including myocardial infarction, heightened levels of cell death require efficient phagocytic debridement to salvage further loss of terminally differentiated adult cardiomyocytes. Additional risk factors, including insulin resistance and other systemic risk factors, contribute to inefficient phagocytosis, altered phagocytic signaling, and delayed cardiac inflammation resolution. Under such conditions, inflammatory presentation of myocardial antigen may lead to autoimmunity and even possible rejection of transplanted heart allografts. Increased understanding of these basic mechanisms offers therapeutic opportunities.

C-reactive protein levels predict systolic heart failure and outcome in patients with first ST-elevation myocardial infarction treated with coronary angioplasty

INTRODUCTION

There is growing evidence that inflammation plays a pivotal role in the etiology and progression of atherosclerosis. High C-reactive protein (CRP) levels have been associated with high mortality in patients with acute myocardial infarction (AMI). Furthermore, in animal models CRP has been found to significantly increase infarct size. So there is growing evidence that CRP is not only a marker for cardiovascular disease but also might be pathogenic. The aim of our study was to test the hypothesis that peak CRP levels could predict heart failure (HF) in ST-elevation myocardial infarction (STEMI) patients.

MATERIAL AND METHODS

Eighty-one consecutive patients with STEMI were prospectively enrolled in the study. C-reactive protein concentrations were measured on admission and after 6, 12, 24, 30, 48, 72 and 96 h. We assessed the association between the elevation of CRP, heart failure and cardiovascular mortality following the first 12 months after STEMI.

RESULTS

C-reactive protein levels reached a peak after 48 h. Patients with STEMI and signs of HF showed significantly higher peak CRP levels. We found a positive correlation between maximum CK levels and peak CRP and a negative correlation between left ventricular ejection fraction (EF) and peak CRP. One year total mortality and HF mortality rates were found to be higher in patients with peak CRP > 47.5 mg/l than in those with CRP below that level (p < 0.001).

CONCLUSIONS

Peak CRP levels in STEMI patients predict emergence of HF. Peak CRP is also a strong predictor of global and cardiovascular mortality during the following year after STEMI.

Prediction of Infarct Transmurality From C-Reactive Protein Level and Mean Platelet Volume in Patients With ST-Elevation Myocardial Infarction: Comparison of the Predictive Values of Cardiac Enzymes

BACKGROUND

High C-reactive protein (CRP) and mean platelet volume (MPV) levels are associated with poor prognosis in patients with ST-segment elevation myocardial infarction (STEMI). The aim of this study was to evaluate the relationship between CRP level or MPV and infarct transmurality in patients with STEMI.

METHODS

We retrospectively reviewed CRP level, MPV, and infarct transmurality in 112 STEMI patients who were assessed with contrast-enhanced cardiac magnetic resonance imaging.

RESULTS

When the cut-off peak CRP level and MPV were set at 2.35 mg/dl and 7.3 fl using receiver operating characteristic curves analysis, the sensitivity was 67.3/69.2% and specificity was 76.7/76.7% for differentiating between the groups with and those without transmural involvement. Peak CRP level, MPV, peak creatine kinase-MB (CK-MB) level, and peak high-sensitivity cardiac troponin T (hs-cTnT) level had comparable predictive values for transmural involvement (area under the curve, 0.749, 0.761, 0.680, and 0.696, respectively). High peak CRP level and MPV were independent predictors of transmural involvement after adjusting for the peak CK-MB level, peak hs-cTnT level, baseline thrombolysis in myocardial infarction flow grade, and left ventricular ejection fraction (odds ratio: 5.16/5.42, 95% confidence interval: 1.84-14.50/2.03-14.47, P = 0.002/0.001, respectively) in the logistic regression analysis.

CONCLUSION

The results of this study show that peak CRP level and MPV are predictive markers for transmural involvement. Their predictive power for transmural involvement is independent of and comparable to that of peak CK-MB and hs-cTnT levels.