Anticoagulant-related nephropathy: systematic review and meta-analysis.

BACKGROUND: The aim of this study was to report the prevalence and mortality associated with anticoagulant-related nephropathy (ARN) through a systematic review of the literature. METHODS: Electronic searches were conducted in the Medline and EMBASE databases, and manual searches were performed in the reference lists of the identified studies. The studies were selected by two independent researchers, first by evaluating the titles and abstracts and then by reading the complete texts of the identified studies. Case series, cross-sectional studies, cohort studies and case-control studies reporting the prevalence and factors associated with ARN were selected. The methodological quality was assessed using the Newcastle-Ottawa scale. Meta-analyses of the prevalence of ARN and 5-year mortality using the random effects model were performed when possible. Heterogeneity was assessed using the I 2 statistic. RESULTS: Five studies were included. Prevalence of ARN ranged from 19% to 63% among the four included cohort studies. Meta-analysis of these resulted in high heterogeneity [I 2 96%, summary effect 31%; 95% confidence interval (CI) 22-42%]. Subgroup meta-analysis yielded an ARN prevalence of 20% among studies that included patients with fewer comorbidities (I 2 12%; 95% CI 19-22%). In a direct comparison, meta-analysis of the 5-year mortality rate between anticoagulated patients who had experienced ARN and anticoagulated patients without ARN, patients with ARN were 91% more likely to die (risk ratio = 1.91; 95% CI 1.22-3; I 2 87%). Risk factors for ARN that were reported in the literature included initial excessive anticoagulation, chronic kidney disease, age, diabetes, hypertension, cardiovascular disease and heart failure. CONCLUSIONS: ARN studies are scarce and heterogeneous, and present significant methodological limitations. The high prevalence of ARN reported herein suggests that this entity is underdiagnosed in clinical practice. Mortality in patients with ARN seems to be high compared with patients without this condition in observational studies.

Lung Lavage and Surfactant Replacement During Ex Vivo Lung Perfusion for Treatment of Gastric Acid Aspiration-Induced Donor Lung Injury.

BACKGROUND: Ex vivo lung perfusion (EVLP) provides opportunities to treat injured donor lungs before transplantation. We investigated whether lung lavage, to eliminate inflammatory inhibitory components, followed by exogenous surfactant replacement, could aid lung recovery and improve post-transplant lung function after gastric aspiration injury. METHODS: Gastric acid aspiration was induced in donor pigs, which were ventilated for 6 hours to develop lung injury. After retrieval and 10 hours of cold preservation, EVLP was performed for 6 hours. The lungs were randomly divided into 4 groups (n = 5, each): (1) no treatment (control), (2) lung lavage, (3) surfactant administration, and (4) lung lavage, followed by surfactant administration. After another 2-hour period of cold preservation, the left lung was transplanted and reperfused for 4 hours. RESULTS: Physiologic lung function significantly improved after surfactant administration during EVLP. The EVLP perfusate from the lavage + surfactant group showed significantly lower levels of interleukin (IL)-1ß, IL-6, IL-8, and secretory phospholipase A2. Total phosphatidylcholine was increased, and minimum surface tension was recovered to normal levels (≤5 mN/m) in the bronchioalveolar fluid after surfactant administration. Lysophosphatidylcholine in bronchioalveolar fluid was significantly lower in the lavage + surfactant group than in the surfactant group. Post-transplant lung function was significantly better in the lavage + surfactant group compared with all other groups. CONCLUSIONS: Lung lavage, followed by surfactant replacement during EVLP, reduced inflammatory mediators and prevented hydrolysis of phosphatidylcholine, which contributed to the superior post-transplant function in donor lungs with aspiration injury.

Mesenchymal stem cell treatment is associated with decreased perfusate concentration of interleukin-8 during ex vivo perfusion of donor lungs after 18-hour preservation.

BACKGROUND: Ex vivo lung perfusion (EVLP) presents a unique therapeutic opportunity to administer mesenchymal stromal cells (MSCs) to lung grafts before transplantation. We sought to determine the optimal route and dose of viable human umbilical cord-derived MSCs to be delivered into ex vivo-perfused damaged swine lungs, and to measure their effect on concentration of growth factors and inflammatory mediators. METHODS: Pig lungs were conventionally retrieved, cold preserved for 18 hours, and perfused normothermically ex vivo for 12 hours. Physiologic data were recorded. No cells were administered to a control group of animals (n = 5). To examine the routes of administration, lungs were administered 50 × 106 MSCs endobronchially (n = 3) or via the pulmonary artery (n = 3). To determine the doses, a dose-escalation study was performed wherein lungs were administered 50 × 106 (n = 3), 150 × 106 (n = 5) and 300 × 106 (n = 3) MSCs via the pulmonary artery. Concentrations of human growth factors and pig cytokines were measured in lung biopsies and perfusate. RESULTS: Intravascular administration of 50 × 106 MSCs was associated with significant and sustained retention of MSCs in lung parenchyma, whereas intrabronchial administration was not. Intravascular administration of 150 × 106 MSCs was the optimal tolerated dose and was associated with increased concentrations of human vascular endothelial growth factor (VEGF) in lung biopsies and decreased concentrations of pig interleukin-8 (IL-8) in the perfusate during 12 hours of EVLP. CONCLUSIONS: Intravascular delivery of 150 × 106 MSCs showed preferred outcome compared with intrabronchial delivery to damaged lungs perfused ex vivo. The method was well tolerated and associated with an increased concentration of human VEGF in the lung tissue and a decreased concentration of pig IL-8 in the perfusate.