Cytokine Signature in Infective Endocarditis

Exploring the Risk Factors and Possible Role of Calcium in Infective Endocarditis

Infective endocarditis (IE) is a severe and potentially life-threatening infection that affects the endocardium, the inner lining of the heart chambers and valves. Although rare, it is a potentially fatal condition, with an incidence of 3-10 cases per 100,000 people per year in developed countries and a mortality rate of up to 30% within 30 days. Early identification and diagnosis are critical for improving outcomes. The diagnosis of IE typically involves a combination of biomarkers, blood cultures, and echocardiography. However, currently, there are no specific biomarkers for the early detection of IE. Given the lack of specific biomarkers for IE, serum calcium levels have been suggested to play a unique role in IE. There have been few articles on the correlation between serum calcium and IE, suggesting that patients with endocarditis and lower levels of serum calcium may have a poorer prognosis. Therefore, in this article, we focus on biomarkers of endocarditis and discuss the evidence showing serum calcium as a potential indicator of IE.

Prognostic implications of ultra-short heart rate variability indices in hospitalized patients with infective endocarditis

BACKGROUND

Infective endocarditis (IE) is a disease that poses a serious health risk. It is important to identify high-risk patients early in the course of their treatment. In the current study, we evaluated the prognostic value of ultra-short heart-rate variability (HRV), an index of vagal nerve activity, in IE.

METHODS

Retrospective analysis was performed on adult patients admitted to a tertiary hospital due to IE. A logistic regression (LR) was used to determine whether clinical, laboratory, and HRV parameters were predictive of specific clinical features (valve type, staphylococcal infection) or severe short-term complications (cardiac, metastatic infection, and death). The accuracy of the model was evaluated through the measurement of the area under the curve (AUC) of the receiver operating characteristic curve (ROC). An analysis of survival was conducted using Cox regression. A number of HRV indices were calculated, including the standard deviation of normal heart-beat intervals (SDNN) and the root mean square of successive differences (RMSSD).

RESULTS

75 patients, aged 60.3(±18.6) years old, were examined. When compared with published age- and gender-adjusted HRV norms, SDNN and RMSSD were found to be relatively low in our cohort (75%-76% lower than the median; 33%-41% lower than the 2nd percentile). 26(34.6%) patients developed a metastatic infection, with RMSSD<7.03ms (adjusted odds ratio (aOR) 9.340, p = 0.002), incorporated in a multivariate LR model (AUC 0.833). Furthermore, 27(36.0%) patients were diagnosed with Staphylococcus IE, with SDNN<4.92ms (aOR 5.235, p = 0.004), a major component of the multivariate LR model (AUC 0.741). Multivariate Cox regression survival model, included RMSSD (HR 1.008, p = 0.012).

CONCLUSION

SDNN, and particularly RMSSD, derived from ultra-short ECG recordings, may provide prognostic information about patients presenting with IE.

Effect of hydro-alcoholic extract of Panax ginseng and Ampicillin treatment in an animal model of Listeria monocytogenes-induced endocarditis

Objective

Endocarditis is a rare but serious infection caused by Listeria monocytogenes. Panax ginseng demonstrated multiple immunomodulatory effects in earlier studies. Ampicillin is known as an effective antibiotic in the treatment of this disease. Therefore, this study aimed to evaluate the effect of hydro-alcoholic extract of P. ginseng and ampicillin treatment in an animal model of Listeria monocytogenes-induced endocarditis.

Materials and Methods

Thirty mice, 5-7 weeks old, were randomly divided into five groups (n=6) including Healthy Control, Infected, Ampicillin (20 mg/kg, subcutaneous) treatment, Ginseng (0.025 mg/kg, intraperitoneal) treatment, and Ginseng (0.025 mg/kg, intraperitoneal) +Ampicillin (15 mg/kg, subcutaneous) treatment groups. The concentration of cytokines in heart tissue, such as IL-1 (interleukine-1), IL-6, IL-8, and TNF-α (Tumor Necrosis Factor-α), was measured. Histopathological changes were evaluated in heart tissues.

Results

The levels of cytokines were significantly decreased in the Ampicillin+Ginseng treated group compared to the other experimental groups. Microscopically, pathologic changes in heart tissue were concomitant with biochemical findings, which in the infected group, neutrophils and mononuclear cells infiltration in endocardial tissue, myocardial cell necrosis, and edema were detectable. The Ampicillin+Ginseng group showed no significant changes compared to the normal control group.

Conclusion

This study showed that ginseng hydro-alcoholic extract plus ampicillin has better efficacy than the extract or antibiotic alone against experimental endocarditis caused by Listeriosis.

Effect of intraoperative haemoadsorption therapy on cardiac surgery for active infective endocarditis with confirmed Staphylococcus aureus bacteraemia

OBJECTIVES

Sepsis caused by infective endocarditis (IE), due to Staphylococcus aureus, is associated with significant morbidity and mortality. Blood purification using haemoadsorption (HA) may attenuate the inflammatory response. We investigated the effect of intraoperative HA on postoperative outcomes in S. aureus IE.

METHODS

Patients with confirmed S. aureus IE undergoing cardiac surgery were included in a dual-centre study between January 2015 and March 2022. Patients treated with intraoperative HA (HA group) were compared to patients not treated with HA (control group). The primary outcome was vasoactive-inotropic score within the first 72 h postoperatively and secondary outcomes were sepsis-related mortality (SEPSIS-3 definition) and overall mortality at 30 and 90 days.

RESULTS

No differences in baseline characteristics were observed between groups (haemoadsorption group, n = 75, control group, n = 55). Significantly decreased vasoactive-inotropic score was observed in the haemoadsorption group at all time points [6 h: 6.0 (0-17) vs 17 (3-47), P = 0.0014; 12 h: 2 (0-8.3) vs 5.9 (0-37), P = 0.0138; 24 h: 0 (0-5) vs 4.9 (0-23), P = 0.0064; 48 h: 0 (0-2.1) vs 0.1 (0-13), P = 0.0192; 72 h: 0 (0) vs 0 (0-5), P = 0.0014]. Importantly, sepsis-related mortality (8.0% vs 22.8%, P = 0.02) and 30-day (17.3% vs 32.7%, P = 0.03) and 90-day overall mortality (21.3% vs 40%, P = 0.03) were also significantly lower with haemoadsorption.

CONCLUSIONS

Intraoperative HA during cardiac surgery for S. aureus IE was associated with significantly lower postoperative vasopressor and inotropic requirements and resulted in lower sepsis-related and overall 30- and 90-day mortality. In this high-risk population, improved postoperative haemodynamic stabilization by intraoperative HA appears to improve survival and should be further tested in future randomized trials.

A Fatal Case of Native Valve Endocarditis with Multiple Embolic Phenomena and Invasive Methicillin-Resistant Staphylococcus aureus Bacteremia: A Case Report from the Maldives

Infective endocarditis (IE) is a life-threatening condition caused by infection within the endocardium of the heart and commonly involves the valves. The subsequent cascading inflammation leads to the appearance of a highly friable thrombus that is large enough to become lodged within the heart chambers. As a result, fever, fatigue, heart murmurs, and embolization phenomena may be seen in patients with IE. Embolization results in the seeding of bacteria and obstruction of circulation, causing cell ischemia. Of concern, bacteria with the potential to gain pan-drug resistance, such as methicillin-resistant Staphylococcus aureus (MRSA), are increasingly being identified as the causative agent of IE in hospitals and among intravenous drug abusers. We retrospectively reviewed de-identified clinical data to summarize the clinical course of a patient with MRSA isolated using an automated blood culture system. At the time of presentation, the patient showed a poor consciousness level, and the calculated Glasgow scale was 10/15. A high-grade fever with circulatory shock indicated an occult infection, and a systolic murmur was observed with peripheral signs of embolization. This case demonstrated the emerging threat of antimicrobial resistance in the community and revealed clinical findings of IE that may be helpful to clinicians for the early recognition of the disease. The management of such cases requires a multi-specialty approach, which is not widely available in small-island developing states such as the Maldives.

VEGF gene polymorphism in complicated infective endocarditis

Introduction. Infective endocarditis (IE) is a bacterial disease with frequent pathogen localization on the heart valve apparatus. IE is characterized by rapid development of heart failure and frequent thromboembolic complications (TEC). IE features are accounted for by foreign pathogen nature and state of human immune system (IS). The imbalanced IS in infective endocarditis is manifested by impaired cytokine-mediated interactions. This confirms the rationality of studying cytokines to advance understanding of the pathogenesis for various conditions. Most cytokine genes are characterized by polymorphism and existing isoforms underlying disease predisposition. Genetic polymorphism of vascular endothelial growth factor A (VEGF-A) plays an important role in the induction of vasculogenesis and angiogenesis. The pathogenetic VEGF role in IE has not been thoroughly studied. Research objective analysis of polymorphic nucleotide sequence variants in the vascular endothelial growth factor gene, taking into account a relation with its serum concentration in patients with infective endocarditis. Materials and methods. 86 patients treated with verified diagnosis of infective endocarditis at the Scientific Research Institute Regional Clinical Hospital No. 1 of Krasnodar were divided into two clinical groups in accordance with the IE course: Group 1 IE with TEC (n = 44), group 2 IE without TEC (n = 42), and the control group consisted of 20 apparently healthy individuals. The concentration of serum VEGF-A (pg/mL) was measured by ELISA on day 1 of hospitalization. Genomic DNA was isolated from whole blood leukocytes and used to determine the frequency of genotypes of VEGF gene polymorphic variants. Results. Significant differences in the frequency distribution of VEGF-rs2010963 genotypes between patients with infective endocarditis and control group were revealed: G/G (OR = 0.25; p = 0.012) and G/C (OR = 4.28; p = 0.022), as well as differences between VEGF concentrations for various SNP-rs2010963 genotypes (p = 0.0001). A study of VEGF genotype frequency distribution between patients of clinical groups showed a significantly decreased frequency of the genotype G/G (rs2010963) in the IE group with TEC (OR = 0.21; p = 0.014) and increased frequency of G/C (OR = 4.72; p = 0.024) compared with the control group, whereas in patients with IE without TEC, significant (p = 0.0003) differences in serum concentrations of VEGF-rs2010963 were found in accordance with genotypes GG/CC (p = 0.01) and GG/GC (p = 0.003). Conclusion. The relationship between the VEGF genotypes (G/G and G/C of rs2010963 polymorphism) and related serum concentration among patients with IE was revealed. Carriers of the minor C allele (rs2010963) had higher serum VEGF levels. The results obtained complement and systematize current scientific data on the disease pathogenesis, as well as focus on the genetic determinant of the developing complications.

Intraoperative hemoadsorption in high-risk patients with infective endocarditis

Background

Postoperative sepsis is an important cause of morbidity and mortality in patients with infective endocarditis undergoing surgical therapy. Blood purification using hemoadsorption therapy shows promising results in the treatment of sepsis. In this study, the clinical effects of intraoperative hemoadsorption in high-risk patients with infective endocarditis were evaluated.

Methods

Eligible candidates were high-risk patients with infective endocarditis undergoing cardiac surgery between January 2014 and December 2019. Patients with intraoperative hemoadsorption (hemoadsorption) were compared to patients without hemoadsorption (control). The endpoints were the incidence of postoperative sepsis, sepsis-associated death and in-hospital mortality. Additionally, postoperative vasopressor need, systemic vascular resistance indices and Sequential Organ Failure Assessment (SOFA) scores were compared.

Results

After propensity score matching, 70 high-risk patients were included. Postoperative sepsis occurred in 14 patients in the hemoadsorption group and in 16 patients in the control group, p = 0.629. Four patients died due to postoperative sepsis in the hemoadsorption group, while 11 postoperative septic patients died in the control group, p = 0.041. In-hospital mortality was 34% in the hemoadsorption group versus 43% in the control group, p = 0.461. On ICU-admission and the first postoperative day, the cumulative vasopressor need was 0.17 versus 0.25 μg/kgBW/min, p = 0.123 and 0.06 versus 0.11 μg/kgBW/min, p = 0.037, and the systemic vascular resistance index was 1448 versus 941 dyn·s·cm-5, p = 0.013 and 1156 versus 858 dyn·s·cm-5, p = 0.110 in the hemoadsorption versus control group, respectively. Postoperative course of SOFA score normalized significantly (p = 0.01) faster in the hemoadsorption group.

Conclusions

In high-risk cardiac surgical patients with infective endocarditis, intraoperative hemoadsorption significantly reduced sepsis-associated mortality. Furthermore, intraoperative hemoadsorption resulted in significant faster recovery of hemodynamics and organ function. Intraoperative hemoadsorption seems to attenuate the severity of postoperative sepsis.

Anesthesia Considerations in Infective Endocarditis

The management of infective endocarditis is complex and inherently requires multidisciplinary cooperation. About half of all patients diagnosed with infective endocarditis will meet the criteria to undergo cardiac surgery, which regularly takes place in urgent or emergency settings. The pathophysiology and clinical presentation of infective endocarditis make it a unique disorder within cardiac surgery that warrants a thorough understanding of specific characteristics in the perioperative period. This includes, among others, echocardiography, coagulation, bleeding management, or treatment of organ dysfunction. In this narrative review article, the authors summarize the current knowledge on infective endocarditis relevant for the clinical anesthesiologist in perioperative management of respective patients. Furthermore, the authors advocate for the anesthesiologist to become a structural member of the endocarditis team.

Progesterone Suppresses Neisseria gonorrhoeae-Induced Inflammation Through Inhibition of NLRP3 Inflammasome Pathway in THP-1 Cells and Murine Models

Asymptomatic/subclinical gonococcal infections in females continue to be prevalent within the general population, thus emerging as a global health problem. However, the reasons for these clinical manifestations are unknown. Our group had previously found out that in females, asymptomatic gonococcal infections correlate with higher serum progesterone (P4) levels and lower IL-1β levels in cervical secretions. We used murine infection model and THP-1 cells to determine whether P4 exerts anti-inflammatory effects on gonococcal infections. In the murine infection model, P4 (1 mg/day) inhibited the inflammatory effects induced by gonococcal infections which led to decreased neutrophil infiltration, reduced polymorphonuclear neutrophils (PMNs) numbers, IL-1β, TNF-α, and IL-6 levels in vaginal secretions. In addition, P4 down-regulated the mRNA and protein levels of NLRP3, associated with lower mRNA levels of pro-IL-1β, repressed caspase-1 activity in genital tissues and THP-1 cells. Moreover, P4 suppressed the phosphorylation levels of NF-κB and attenuated Neisseria gonorrhoeae (N. gonorrhoeae, gonococci or GC)-induced ROS generation. This is consistent with the two signals required for activation of the NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome. In conclusion, our result shows that P4 suppresses the gonococci induced-inflammation, especially through the NLRP3 inflammasome pathway, and partially explains the pathogenesis of asymptomatic GC infection in women.

Hemoadsorption during Cardiopulmonary Bypass in Patients with Endocarditis Undergoing Valve Surgery: A Retrospective Single-Center Study

Background: Aim of this study was to evaluate the outcomes of endocarditis patients undergoing valve surgery with the Cytosorb^® hemoadsorption (HA) device during cardiopulmonary bypass. Methods: From 2009 until 2019, 241 patients had undergone valve surgery due to endocarditis at the Department of Cardiac Surgery, University Hospital of Basel. We compared patients who received HA during surgery (n = 41) versus patients without HA (n = 200), after applying inverse probability of treatment weighting. Results: In-hospital mortality, major adverse cardiac and cerebrovascular events and postoperative renal failure were similar in both groups. Demand for norepinephrine (88.4 vs. 52.8%; p = 0.001), milrinone (42.2 vs. 17.2%; p = 0.046), red blood cell concentrates (65.2 vs. 30.6%; p = 0.003), and platelets (HA vs. Control: 36.7 vs. 9.8%; p = 0.013) were higher in the HA group. In addition, a higher incidence of reoperation for bleeding (34.0 vs. 7.7 %; p = 0.011), and a prolonged length of in-hospital stay (15.2 (11.8 to 19.6) vs. 9.0 (7.1 to 11.3) days; p = 0.017) were observed in the HA group. Conclusions: No benefits of HA-therapy were observed in patients with infective endocarditis undergoing valve surgery.

[The expression level of cytokine genes in the cases of native heart valves in infectious endocarditis]

The expression level of IL1B, IL6, IL8, IL10, IL12A, IL12B, IL18, IL23, IL33, CCL2, and IL1RL1 has been investigated using biopsies of native mitral, aortic, and tricuspid valves obtained during surgical correction of acquired defect from 25 patients with infectious endocarditis. Biopsies of native mitral and aortic valve cusps from 12 patients who underwent surgical correction of acquired heart disease of non-infectious etiology were used as control. We used quantitative PCR with fluorescent dye SYBR Green for determination of the cytokine gene expression level. This study revealed that genes could be subdivided into three groups: (i) genes with increased expression (IL1B, IL6, and IL8); (ii) genes with reduced expression (IL33 and IL1RL1); (iii) genes with unchanged expression (IL12A, IL18, IL23, and CCL2). The IL8 gene expression was characterized by the most pronounced increase (9.83 times versus control), while the IL1RL1 gene demonstrated the most pronounced decrease in its expression (4.17 times). Expression of IL10 and IL12B genes was negligible in all samples.

Proteomics of extracellular vesicles produced by Granulicatella adiacens, which causes infective endocarditis

When oral bacteria accidentally enter the bloodstream due to transient tissue damage during dental procedures, they have the potential to attach to the endocardium or an equivalent surface of an indwelling prosthesis and cause infection. Many bacterial species produce extracellular vesicles (EVs) as part of normal physiology, but also use it as a virulence strategy. In this study, it was hypothesized that Granulicatella adiacens produce EVs that possibly help it in virulence. Therefore, the objectives were to isolate and characterize EVs produced by G. adiacens and to investigate its immune-stimulatory effects. The reference strain G. adiacens CCUG 27809 was cultured on chocolate blood agar for 2 days. From subsequent broth culture, the EVs were isolated using differential centrifugation and filtration protocol and then observed using scanning electron microscopy. Proteins in the vesicle preparation were identified by nano LC-ESI-MS/MS. The EVs proteome was analyzed and characterized using different bioinformatics tools. The immune-stimulatory effect of the EVs was studied via ELISA quantification of IL-8, IL-1β and CCL5, major proinflammatory cytokines, produced from stimulated human PBMCs. It was revealed that G. adiacens produced EVs, ranging in diameter from 30 to 250 nm. Overall, G. adiacens EVs contained 112 proteins. The proteome consists of several ribosomal proteins, DNA associated proteins, binding proteins, and metabolic enzymes. It was also shown that these EVs carry putative virulence factors including moonlighting proteins. These EVs were able to induce the production of IL-8, IL-1β and CCL5 from human PBMCs. Further functional characterization of the G. adiacens EVs may provide new insights into virulence mechanisms of this important but less studied oral bacterial species.

Tyrosine tRNA synthetase as a novel extracellular immunomodulatory protein in Streptococcus anginosus

Streptococcus anginosus is frequently detected in patients with infective endocarditis, abscesses or oral cancer. Although S. anginosus is considered the causative pathogen of these diseases, the pathogenic mechanisms of the bacterium have remained unclear. Previously, we suggested that an extracellular antigen from S. anginosus (SAA) serves as a pathogenic factor by inducing nitric oxide production in murine macrophages. In the present study, we identified SAA using LC-MS/MS and assessed the biological activities of His-tagged recombinant SAA in murine macrophages. SAA was identified as a tyrosine tRNA synthetase (SaTyrRS) that was isolated from the extracellular fraction of S. anginosus but not from other oral streptococci. In addition, inducible nitric oxide synthase and TNF-α mRNA expression was induced in recombinant SaTyrRS-stimulated murine macrophages. However, their mRNA expression was not induced in macrophages stimulated with truncated or heat-inactivated recombinant SaTyrRS, and the activation motif was identified as Arg264-Thr270. Consequently, these results indicated that SaTyrRS could be a novel and specific immunomodulatory protein in S. anginosus.

Widespread septic embolization in injection drug use mitro-aortic infective endocarditis as a remote cause of death

Injection drug use-related infective endocarditis (IDU-IE) assumes peculiar epidemiological, pathogenetic, and prognostic characteristics that allow to consider it a distinct nosological entity, as well as a current problem of considerable social weight. Incidence is reasonably underestimated because diagnosis is often accidental in postmortem examination when drug-related death is suspected. In many cases, postmortem toxicological examinations are negative for acute drug abuse, and findings of infective endocarditis became relevant in the explanation of the mechanism of death. Extracardiac involvement of infective endocarditis is rarely reported as fatal. Fragmentation and embolization of bacterial vegetations can be associated with parenchymal infarcts, systemic spread of the infectious process by formation of an abscess. A case of septic shock as a consequence of the constant bacteremia determined by the continuous proliferation and release of bacteria into the circulation is presented in an injection drug user with left-sided endocarditis and widespread septic embolization. Authors reviewed forensic and medical literature and promote epidemiological value of medical and forensic autopsy. Extracardiac involvement of infective endocarditis may represent a remote and alternative cause of death in injection drug users, and an early diagnosis can be relevant for prognosis. Postmortem examination still represents a valuable opportunity of learning for clinicians and improving diagnostic accuracy with injection drug users. A call for changing of attitudes and practice toward autopsy is finally demanded.

Biomarkers for prediction of mortality in left-sided infective endocarditis

BACKGROUND

Evidence regarding biomarkers for risk prediction in patients with infective endocarditis (IE) is limited. We aimed to investigate the value of a panel of biomarkers for the prediction of in-hospital mortality in patients with IE.

METHODS

Between 2016 and 2018, consecutive IE patients admitted to the emergency department were prospectively included. Blood concentrations of nine biomarkers were measured at admission (D0) and on the seventh day (D7) of antibiotic therapy: C-reactive protein (CRP), sensitive troponin I (s-cTnI), procalcitonin, B-type natriuretic peptide (BNP), neutrophil gelatinase-associated lipocalin (NGAL), interleukin 6 (IL6), tumor necrosis factor α (TNF-α), proadrenomedullin, alpha-1-acid glycoprotein, and galectin 3. The primary endpoint was in-hospital mortality.

RESULTS

Among 97 patients, 56% underwent cardiac surgery, and in-hospital mortality was 27%. At admission, six biomarkers were independent predictors of in-hospital mortality: s-cTnI (OR 3.4; 95%CI 1.8-6.4; P<0.001), BNP (OR 2.7; 95%CI 1.4-5.1; P=0.002), IL-6 (OR 2.06; 95%CI 1.3-3.7; P=0.019), procalcitonin (OR 1.9; 95%CI 1.1-3.2; P=0.018), TNF-α (OR 1.8; 95%CI 1.1-2.9; P=0.019), and CRP (OR 1.8; 95%CI 1.0-3.3; P=0.037). At admission, S-cTnI provided the highest accuracy for predicting mortality (area under the ROC curve: s-cTnI 0.812, BNP 0.727, IL-6 0.734, procalcitonin 0.684, TNF-α 0.675, CRP 0.670). After 7 days of antibiotic therapy, BNP and inflammatory biomarkers improved their performance (s-cTnI 0.814, BNP 0.823, IL-6 0.695, procalcitonin 0.802, TNF-α 0.554, CRP 0.759).

CONCLUSION

S-cTnI concentration measured at admission had the highest accuracy for mortality prediction in patients with IE.

Intraoperative Hemoadsorption in Patients With Native Mitral Valve Infective Endocarditis

BACKGROUND

Cardiac surgery in patients with infective endocarditis is associated with high mortality owing to postoperative septic multiorgan failure. Hemoadsorption therapy may improve surgical outcomes by reducing the circulating cytokines. We aimed to evaluate the clinical effects of intraoperative hemoadsorption in patients with mitral valve endocarditis.

METHODS

Eligible candidates were patients with infective endocarditis of the native mitral valve undergoing cardiac surgery between January 2014 and July 2018. Patients with intraoperative hemoadsorption (hemoadsorption) were compared with surgery without hemoadsorption (control). The end points were the incidence of postoperative sepsis, sepsis-associated death, and 30-day mortality. Furthermore, postoperative need for epinephrine and norepinephrine and systemic vascular resistance were evaluated.

RESULTS

A total of 58 consecutive patients were included: 30 in the hemoadsorption group and 28 in the control group. Postoperative sepsis occurred in 5 patients in the hemoadsorption group and in 11 in the control group (P = .05). No sepsis-associated death occurred in the hemoadsorption group, whereas five septic patients in the control group died (P = .02). Thirty-day mortality was 10% in the hemoadsorption group versus 18% in the control group (P = .39). On intensive care unit admission, the cumulative need for epinephrine and norepinephrine was 0.15 versus 0.24 μg/kg body weight/min (P = .01) and the median systemic vascular resistance was 1413 versus 1010 dyn·s·cm^-5 (P = .02) in the hemoadsorption versus control group, respectively.

CONCLUSIONS

Intraoperative hemoadsorption might reduce the incidence of postoperative sepsis and sepsis-related death. In addition, patients with intraoperative hemoadsorption showed greater hemodynamic stability. These data suggest that intraoperative hemoadsorption may improve surgical outcome in patients with mitral valve endocarditis.

Changes in inflammatory and vasoactive mediator profiles during valvular surgery with or without infective endocarditis: A case control pilot study

Background

More than 50% of patients with infective endocarditis (IE) develop an indication for surgery. Despite its benefit, surgery is associated with a high incidence of multiple organ dysfunction syndrome (MODS) and mortality, which may be linked to increased release of inflammatory mediators during cardiopulmonary bypass (CPB). We therefore assessed plasma cytokine profiles in patients undergoing valve surgery with or without IE.

Methods

We performed a prospective case-control pilot study comparing patients undergoing cardiac valve surgery with or without IE. Plasma profiles of inflammatory mediators were measured at 7 defined time points and reported as median (interquartile). The degree of MODS was measured using sequential organ failure assessment (SOFA) score.

Results

Between May and December 2016 we included 40 patients (20 in each group). Both groups showed similar distribution of age and gender. Patients with IE had higher preoperative SOFA (6.9± 2.6 vs 3.8 ± 1.1, p<0.001) and operative risk scores (EuroSCORE II 18.6±17.4 vs. 1.8±1.3, p<0.001). In-hospital mortality was higher in IE patients (35% vs. 5%; p<0.001). Multiple organ failure was the cause of death in all non-survivors. At the end of CPB, median levels of following inflammatory mediators were higher in IE compared to control group: IL-6 (119.73 (226.49) vs. 24.48 (40.09) pg/ml, p = 0.001); IL-18 (104.82 (105.99) vs. 57.30 (49.53) pg/ml, p<0.001); Mid-regional pro-adrenomedullin (MR-proADM) (2.06 (1.58) vs. 1.11 (0.53) nmol/L, p = 0.003); MR- pro-atrial natriuretic peptide (MR-proANP) (479.49 (224.74) vs. 266.55 (308.26) pmol/l, p = 0.028). IL-1β and TNF- α were only detectable in IE patients and first after starting CPB. Plasma levels of IL-6, IL-18, MRproADM, and MRproANP during CPB were significantly lower in survivors than in those who died.

Conclusion

The presence of infective endocarditis during cardiac valve surgery is associated with increased inflammatory response as evident by higher plasma cytokine levels and other inflammatory mediators. Actively reducing inflammatory response appears to be a plausible therapeutic concept.

Trial registration

ClinicalTrials.gov, ID: NCT02727413.

Inflammatory biomarkers in infective endocarditis: machine learning to predict mortality

Infective endocarditis (IE) is the cardiac disease with the highest rates of mortality. New biomarkers that are able to identify patients at risk for death are required to improve patient management and outcome. This study aims to investigate if cytokines, chemokines and growth factors measured at IE diagnosis can predict mortality. Patients with definite IE, according to the Duke's modified criteria, were included. Using high-performance Luminex assay, 27 different cytokines, chemokines and growth factors were analyzed. Machine learning techniques were used for the prediction of death and subsequently creating a decision tree, in which the cytokines, chemokines and growth factors were analyzed together with C-reactive protein (CRP). Sixty-nine patients were included, 41 (59%) male, median age 54 [interquartile range (IQR) = 41-65 years] and median time between onset of the symptoms and diagnosis was 12 days (IQR = 5-30 days). The in-hospital mortality was 26% (n = 18). Proinflammatory cytokines interkeukin (IL)-15 and C-C motif chemokine ligand (CCL4) were found to predict death, adding value to CRP levels. The decision tree predicted correctly the outcome of 91% of the patients at hospital admission. The high-risk group, defined as CRP ≥ 72 mg/dL, IL-15 ≥ 5·6 fg/ml and CCL4 ≥ 6·35 fg/ml had an 88% in-hospital mortality rate, whereas the patients classified as low-risk had a mortality rate of 8% (P = < 0·001). Cytokines IL-15 and CCL4 were predictors of mortality in IE, adding prognostic value beyond that provided by CRP levels. Assessment of cytokines has potential value for clinical risk stratification and monitoring in IE patients.

Lipoproteins in Streptococcus gordonii are critical in the infection and inflammatory responses

Gram-positive bacteria such as Streptococcus gordonii causing life-threatening infective endocarditis are mainly recognized by Toll-like receptor 2 (TLR2). Lipoteichoic acid (LTA) and lipoproteins are representative TLR2 ligands that play important roles in bacterial infection and in host inflammatory responses. In the present study, we generated an LTA-deficient mutant (ΔltaS) and a lipoprotein-deficient mutant (Δlgt) and investigated the contributions of LTA and lipoproteins to bacterial morphology and their effect on induction of proinflammatory cytokines in THP-1 and mouse bone-marrow derived macrophages (BMDMs). Deletion of ltaS and lgt was confirmed by PCR analysis of genomic DNA from each mutant. The mutants with absence of LTA or lipoproteins were examined by SDS-PAGE followed by Western blotting with anti-LTA antibodies and silver staining, respectively. Interestingly, scanning and transmission electron microscopies showed no difference in the bacterial cell morphology or size between the wild-type and the mutants even though substantial changes in the cell size and/or morphology have been reported in other Gram-positive bacteria such as Staphylococcus aureus, Listeria monocytogenes, and Bacillus subtilis. However, S. gordonii wild-type and ΔltaS potently induced the expression of proinflammatory cytokines including TNF-α, IL-8, and IL-1β at the mRNA and protein levels, while Δlgt did not have these effects. Furthermore, lipoproteins purified from S. gordonii also induced the expression of the aforementioned cytokines more potently than the purified LTA. Neither LTA nor lipoprotein induced TNF-α, KC (IL-8 counterpart in mouse), and IL-1β in TLR2-deficient BMDMs. S. gordonii Δlgt was less virulent than the wild-type or ΔltaS in a mouse intraperitoneal infection model. Collectively, these results suggest that S. gordonii lipoproteins, but not LTA, are mainly responsible for the infection and inflammatory responses.

Pseudomonas aeruginosa Invades Human Aortic Endothelial Cells and Induces Cell Damage in vitro

BACKGROUND

Cardiovascular diseases such as endocarditis are the second most common cause of death worldwide. Infective Endocarditis (IE) is the most severe infection of the heart associated with significant mortality and morbidity. The binding and invasion of Human Aortic Endothelial Cells (HAECs) by pathogenic microbes can play an important role in the pathogenesis of IE.

OBJECTIVE

Pseudomonas aeruginosa is an emerging pathogen that has been associated with IE. However, it is not known whether P. aeruginosa can bind and interact with HAECs. The aim of this study was to determine whether P. aeruginosa can bind and colonize HAECs.

METHODS

The invasion of HAECs by P. aeruginosa was assessed by gentamicin protection assay. Cytokine levels were determined by enzyme-linked Immunosorbent Assay (ELISA) kits. Cell damage was determined by Lactate Dehydrogenase (LDH) assay.

RESULTS

P. aeruginosa can bind and invade HAECs. Infection of HAECs with P. aeruginosa induces TNF-α IL-1β, IL-6 and IL-8 cytokine production leading to the generation of inflammatory milieu that can cause tissue damage as observed in human clinical cases of IE. We also observed that P. aeruginosa induces cell damage in HAECs.

CONCLUSION

In this study, we demonstrate for first time that P. aeruginosa can invade and survive inside HAECs. This cell culture model can be of immense importance to determine the efficacy of drug targets against IE.

Cytokine induction of peripheral blood mononuclear cells by biofilms and biofilm supernatants of Granulicatella and Abiotrophia spp

Granulicatella and Abiotrophia species are the normal oral flora bacteria that can occasionally cause infective endocarditis. Although substantial data exists in the literature demonstrating occurrence of these species in infective endocarditis, only a few mechanistic studies on their pathogenicity are found. The aim of this study was to investigate the ability of Granulicatella and Abiotrophia species to elicit immune response from human peripheral blood mononuclear cells (PBMC). Biofilms and biofilm supernatants of Granulicatella elegans CCUG 38949, Granulicatella adiacens CCUG 27809 and Abiotrophia defectiva CCUG 27639 were used to stimulate PBMCs for 24 h. Cytokines produced were first screened using a human cytokine membrane array kit. Further, pro-inflammatory cytokines TNF-α, IL-β, and IL-17 were quantified by ELISA. The cytokine profiler array showed the induction of 15 different cytokines/chemokines including IL-1β, IL-6, IL-8, TNF-α, MCP-1, MIP-1α/MIP-1β and RANTES. ELISA quantification revealed that G. adiacens biofilm induced significantly higher (P < 0.05) levels of IL-1β, i.e., 1931 (183) pg/ml than G. elegans or A. defectiva. However, in the case of biofilm supernatants A. defectiva was the strongest, inducing 2104 (574) pg/ml. Biofilm supernatants, but not biofilms from all three species induced TNF-α only weakly. IL-17 was undetectable from any of the stimulated samples. In conclusion, Granulicatella and Abiotrophia are potent inducers of inflammatory mediators from human PBMCs. However, biofilms and biofilm supernatants from these species seem to selectively elicit stimulation of certain cytokines.

Inherited Variation in Cytokine, Acute Phase Response, and Calcium Metabolism Genes Affects Susceptibility to Infective Endocarditis

Infective endocarditis (IE) is a septic inflammation of the endocardium. Recognition of microbial patterns, cytokine and acute phase responses, hemostasis features, and alterations in plasma lipid and calcium profile all have been reported to affect pathogenesis and clinical course of IE. Having recruited 123 patients with IE and 300 age-, sex-, and ethnicity-matched healthy blood donors, we profiled their genomic DNA for 35 functionally significant polymorphisms within the 22 selected genes involved in the abovementioned pathways, with the further genetic association analysis. We found that the G/A genotype of the rs1143634 polymorphism within the IL1B gene, the G/T genotype of the rs3212227 polymorphism within the IL12B gene, the A/G genotype of the rs1130864 polymorphism within the CRP gene, and the G allele of the rs1801197 polymorphism within the CALCR gene were associated with a decreased risk of IE whereas the T/T genotype of the rs1205 polymorphism within the CRP gene was associated with a higher risk of IE. Furthermore, heterozygous genotypes of the rs1143634 and rs3212227 polymorphisms were associated with the higher plasma levels of IL-1β and IL-12, respectively. Our results indicate that inherited variation in the cytokine, acute phase response, and calcium metabolism pathways may be linked to IE.

Pyrexia's effect on the CBG-cortisol thermocouple, rather than CBG cleavage, elevates the acute free cortisol response to TNF-α in humans

Corticosteroid-binding globulin (CBG) cleavage promotes local cortisol delivery in inflammation. Enzymatic cleavage of high-affinity CBG to low-affinity CBG (haCBG to laCBG) occurs at inflammatory sites and is now measurable in vivo; however, the time kinetics of haCBG depletion following an inflammatory stimulus is unknown. Hence our aim was to determine the immediate effect of the key pro-inflammatory cytokine TNF-α on CBG levels and cleavage. We performed a crossover study of 12 healthy males receiving a TNF-α versus saline infusion, measuring total CBG, haCBG, laCBG and free and total cortisol hourly for 6 h. There was no change in total CBG or haCBG levels in the first 6 h of inflammation between the groups, suggesting that CBG cleavage is not activated nor is hepatic CBG production affected by TNF-α in this time frame. There was an early increase in the ratio of free:total cortisol, in association with pyrexia. This accords with data indicating that CBG acts a thermocouple in vivo, increasing free cortisol levels independent of elastase-driven cleavage.

Dental care before cardiac valve surgery: Is it important to prevent infective endocarditis?

BACKGROUND

Infective endocarditis (IE) is a serious disease that affects the surface of the endocardium. The spread of microorganisms from the oral cavity has been associated with the occurrence of IE.

OBJECTIVE

To analyze whether dental treatment before cardiac valve surgery (CVS) influenced the occurrence of IE.

METHODS

We performed a retrospective analysis of the medical and dental histories of patients undergoing CVS from 2004 to 2014. The sample consisted of 481 patients who underwent CVS divided into two groups: patients submitted to dental treatment prior to CVS (n = 110) and patients undergoing CVS without dental treatment (n = 371).

RESULTS

Of the total sample, 38 patients (8%) were diagnosed with IE. No significant difference was detected (p = 0.496) in comparing the occurrence of IE in the group with dental preparation (6.4%) and without dental preparation (8.4%). The logistic regression model confirmed that dental treatment did not change the IE risk (p = 0.504) and indicated that age (p < 0.003) and gender (p = 0.013) were significant risk factors for IE. There was a high demand for dental procedures in the group receiving dental preparation, with no significant differences between the patients with or without IE. Hemoculture indicated qualitative differences in comparing patients with and without dental treatment, especially in the frequency of Staphylococcus and Streptococcus.

CONCLUSIONS

The results did not allow for the determination of the impact of dental treatment before CVS on IE outcomes. However, it was not possible to exclude the potential beneficial effects of dental treatment in the prevention of IE.

Calcium-Sensing Receptor in Human Peripheral Blood T Lymphocytes Is Involved in the AMI Onset and Progression through the NF-κB Signaling Pathway

Acute myocardial infarction (AMI) is a condition triggered by an inflammatory process that seriously affects human health. Calcium-sensing receptor (CaSR) in T lymphocytes is involved during the inflammation reaction. However, the relationship between them is not very clear. In this study, we collected human peripheral blood T lymphocytes from patients with AMI and in different stages of percutaneous coronary intervention (PCI) (at the onset of AMI, the first day after PCI (PCI-1), PCI-3, and PCI-5) to study the CaSR and NF-κB pathway protein expression, cytokine release and T cell apoptosis. The results showed that the expressions of CaSR, P-p65, Caspase-12, and the secretions of Th-1 and Th-2 type cytokines were increased at the onset of AMI, especially on the PCI-1. Meanwhile, the apoptosis rate of CD(3+), CD(4+) and CD(8+) T lymphocytes also increased. However, from PCI-3, all the indicators began to decline. In addition, we also found that positive CaSR small interfering RNA (siRNA) transfection in T lymphocytes and NF-κB pathway blocker Bay-11-7082 reversed the increased expressions of CaSR, P-p65, Caspase-12, reduced the secretions of Th-1 and Th-2 type cytokines, and decreased T lymphocytes apoptosis rate not only in the AMI patients but also in the normal controls. All of these results indicated that CaSR in the human peripheral blood T lymphocytes were involved in the AMI onset and progression, which probably was related to the NF-κB pathway. Our study demonstrated the relationship between AMI and CaSR, and will provide new effective prevention theory and new targets for drug treatment.