Soluble receptor for advanced glycation end products as an indicator of pulmonary vascular injury after cardiac surgery

Association of Acute Systemic Inflammation with Patient-Centric Postoperative Pulmonary Complications After Elective Cardiac Surgery

BACKGROUND

Postoperative pulmonary complications (PPCs) occur frequently after cardiac surgery. Absolute postoperative values of biomarkers of inflammation (interleukin [IL]-6, IL-8, and tumor necrosis factor-alpha [TNF-α]) and alveolar epithelial injury (soluble receptor for advanced glycation end-products [sRAGE]) have been associated with hypoxia and prolonged ventilation. However, relationships between these biomarkers and PPCs, contextualized to preoperative inflammation and perioperative lung injury risk factors, are uncertain. We aimed to determine associations between perioperative increases in biomarkers of inflammation and alveolar epithelial injury with a patient-centric PPC definition in adult cardiac surgical patients, accounting for the influence of intraoperative risk factors for lung injury.

METHODS

Adults undergoing elective cardiac surgery were eligible for this observational cohort study. Blood concentrations of IL-6, IL-8, TNF-α, and sRAGE were collected after anesthesia induction (baseline) and on postoperative day 1 (POD 1). The primary outcome was the occurrence of moderate or severe PPCs, graded using a validated scale, in POD 0 to 7. We estimated the association between POD 1 IL-6, IL-8, TNF-α, and sRAGE concentrations and moderate/severe PPC presence using separate logistic regression models for each biomarker, adjusted for baseline biomarker values and risk factors for postoperative lung injury (age, baseline PaO2/FiO2, left ventricle ejection fraction [LVEF], procedural type, cardiopulmonary bypass duration, and transfusions). Covariables were chosen based on relevance to lung injury and unadjusted between-group differences among patients with versus without PPCs. The secondary outcome was postoperative ventilation duration, which was log-transformed and analyzed using linear regression, adjusted using the same variables as the primary outcome.

RESULTS

We enrolled 204 patients from 2016 to 2018. Biomarkers were analyzed in 2023 among 175 patients with complete data. In adjusted analyses, POD 1 IL-8 and IL-6 were significantly associated with moderate/severe PPCs. The odds ratio (OR) for developing a PPC for every 50 pg/mL increase in POD 1 IL-8 was 7.19 (95% confidence interval [CI], 2.13-28.53, P = .003) and 1.42 (95% CI, 1.13-1.93, P = .01) for every 50 pg/mL increase in POD 1 IL-6. In adjusted analyses, postoperative ventilation duration was significantly associated with POD 1 sRAGE; each 50 pg/mL increase in sRAGE was associated with a 25% (95% CI, 2%-52%, P = .03) multiplicative increase in hours of ventilation. TNF-α was not significantly associated with PPCs or ventilation duration.

CONCLUSIONS

Acute systemic inflammation is significantly associated with PPCs after elective cardiac surgery in adults when taking into consideration preoperative inflammatory burden and perioperative factors that may influence postoperative lung injury.

Plasma levels of alarmin HNPs 1-3 associate with lung dysfunction after cardiac surgery in children

Background

Early onset of lung injury is considerable common after cardiac surgery and is associated with increasing in morbidity and mortality, but current clinical predictors for the occurrence of this complication always have limited positive warning value. This study aimed to evaluate whether elevated plasma levels of human neutrophil peptides (HNPs) 1–3 herald impaired lung function in infants and young children after cardiac surgery necessitating cardiopulmonary bypass (CPB).

Methods

Consecutive children younger than 3 years old who underwent cardiac surgery were prospectively enrolled. Plasma concentrations of HNPs 1–3 and inflammatory cytokines were measured before, and immediately after CPB, as well as at 1 h, 12 h, and 24 h after CPB.

Results

Thirty patients were enrolled, 18 (60%) of whom were infants. Plasma levels of HNPs 1–3 and the pro-inflammatory cytokine interleukin-6 (IL-6) significantly increased immediately after CPB (P < 0.001), while IL-8 increased 1 h after the CPB operation (P = 0.002). The anti-inflammatory cytokine IL-10 levels were also significantly elevated immediately after CPB compared with the baseline (P < 0.001). The stepwise multiple linear regression analysis showed that the plasma HNPs 1–3 levels immediately after CPB was independent correlated with the declined lung function, as reflected by the PaO₂/FiO₂ ratio on the first 2 days after operation (for the first day: OR, −1.067, 95% CI, −0.548 to −1.574; P < 0.001; for the second day: OR, −0.667, 95% CI, −0.183 to −1.148; P = 0.009) and prolonged mechanical ventilation time (OR, 0.039, 95% CI, 0.005 to 0.056; P = 0.011). Plasma levels of HNPs 1–3 and IL-10 returned to the baseline values, while IL-6 and IL-8 levels remained significantly higher than baseline 24 h after CPB (P ≤ 0.01).

Conclusions

Elevated HNPs 1–3 levels immediately after CPB correlate with impaired lung function, and HNPs 1–3 could serve as a quantifiable early alarmin biomarker for onset of lung injury in infants and young children undergoing cardiac surgery with CPB.

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0558-4) contains supplementary material, which is available to authorized users.

Intraoperative cell salvage during cardiac surgery is associated with reduced postoperative lung injury

OBJECTIVES

In addition to its blood-sparing effects, intraoperative cell salvage may reduce lung injury following cardiac surgery by removing cytokines, neutrophilic proteases and lipids that are present in cardiotomy suction blood. To test this hypothesis, we performed serial measurements of biomarkers of the integrity of the alveolar-capillary membrane, leucocyte activation and general inflammation. We assessed lung injury clinically by the duration of postoperative mechanical ventilation and the alveolar arterial oxygen gradient.

METHODS

Serial measurements of systemic plasma concentrations of interleukin-6 (IL-6), myeloperoxidase, elastase, surfactant protein D (SP-D), Clara cell 16 kD protein (CC16) and soluble receptor for advanced glycation endproducts (sRAGEs) were performed on blood samples from 195 patients who underwent cardiac surgery with the use of a cell salvage (CS) device (CS, n = 99) or without (CONTROL, n = 96).

RESULTS

Postoperative mechanical ventilation time was shorter in the CS group than in the CONTROL group [10 (8-15) vs 12 (9-18) h, respectively, P = 0.047]. The postoperative alveolar arterial oxygen gradient, however, was not different between groups. After surgery, the lung injury biomarkers CC16 and sRAGEs were lower in the CS group than in the CONTROL group. Biomarkers of systemic inflammation (IL-6, myeloperoxidase and elastase) were also lower in the CS group. Finally, mechanical ventilation time correlated with CC16 plasma concentrations.

CONCLUSIONS

The intraoperative use of a cell salvage device resulted in less lung injury in patients after cardiac surgery as assessed by lower concentrations of lung injury markers and shorter mechanical ventilation times.

Plasma level of advanced oxidation protein products as a novel biomarker of acute lung injury following cardiac surgery

This study was designed to test the hypothesis that whether the plasma level of advanced oxidant protein products (AOPPs) would be useful for the clinical diagnosis of acute lung injury (ALI) following cardiac surgery with the technique of cardiopulmonary bypass (CPB). In this prospective study, seventy consecutive adults undergoing open heart surgery with CPB were included and assigned into the ALI (n = 18) and non-ALI (n = 52) groups according to the American-European Consensus Criteria. Plasma concentrations of AOPPs were measured at baseline, postoperative 1 h, 12 h, 24 h, and 48 h. Eighteen patients (25.7 %) developed ALI after surgery. The plasma levels of AOPPs in the ALI group were significantly increased and remained considerably higher at all time points after operation (all P < 0.05). Multivariate logistic regression analysis revealed that the plasma level of AOPPs at 1 h after operation was an independent predictor for the diagnosis of ALI (OR 1.164; 95 % CI 1.068–1.269; P = 0.001). Plasma level of AOPPs could serve as an early biomarker of the incidence of ALI in adult patients who underwent open cardiac surgery with the technique of CPB.

Biomarkers of lung injury in cardiothoracic surgery

Diagnosis of pulmonary dysfunction is currently almost entirely based on a vast series of physiological changes, but comprehensive research is focused on determining biomarkers for early diagnosis of pulmonary dysfunction. Here we discuss the use of biomarkers of lung injury in cardiothoracic surgery and their ability to detect subtle pulmonary dysfunction in the perioperative period. Degranulation products of neutrophils are often used as biomarker since they have detrimental effects on the pulmonary tissue by themselves. However, these substances are not lung specific. Lung epithelium specific proteins offer more specificity and slowly find their way into clinical studies.

Elevation of soluble form of receptor for advanced glycation end products (sRAGE) in recurrent pregnancy losses (RPL): possible participation of RAGE in RPL

OBJECTIVE

To determine whether the soluble receptor for advanced glycation end products (sRAGE) and immune inflammatory markers are associated with recurrent pregnancy losses (RPL).

DESIGN

Prospective case-control study.

SETTING

University clinic.

PATIENT(S)

A total of 93 women (age 35.8±4.6 years) were enrolled including 63 women with three or more recurrent pregnancy losses (RPL), and age-matched fertile controls with a history of at least one live birth and no history of pregnancy losses (n=30).

INTERVENTION(S)

Peripheral blood collection.

MAIN OUTCOME MEASURE(S)

Assessment of anthropometric, metabolic, and inflammatory immune variables.

RESULT(S)

Levels of sRAGE were statistically significantly higher in RPL patients than in control patients (1,528.9±704.5 vs. 1,149.9±447.4 pg/mL). In the multivariate analysis, the levels of insulin, plasminogen activator inhibitor-1, the resistance index of the uterine radial artery, and the ratio of tumor necrosis factor-α/interleukin-10 producing T helper cells were statistically significantly associated with the serum sRAGE level.

CONCLUSION(S)

Elevated levels of serum sRAGE are associated with RPL. The soluble receptor for advanced glycation end products might contribute to RPL by reducing uterine blood flow and subsequently causing ischemia in the fetus via inflammatory and thrombotic reactions.