Clinical Utility of Pepsin and Bile Acid in Tracheal Secretions for Accurate Diagnosis of Aspiration in ICU Patients.

BACKGROUND: Aspiration of stomach content or saliva in critical conditions-e.g., shock, intoxication, or resuscitation-can lead to acute lung injury. While various biomarkers in bronchoalveolar lavage fluids have been studied for diagnosing aspiration, none have been conclusively established as early indicators of lung damage. This study aims to evaluate the diagnostic value of pepsin, bile acid, and other biomarkers for detecting aspiration in an intensive care unit (ICU). MATERIALS AND METHODS: In this study, 50 ICU patients were enrolled and underwent intubation before admission. The evaluation of aspiration was based on clinical suspicion or documented instances of observed events. Tracheal secretion (TS) samples were collected within 6 h after intubation using sterile suction catheters. Additional parameters, including IL-6, pepsin, and bile acid, were determined for analysis. Pepsin levels were measured with an ELISA kit, while bile acid, uric acid, glucose, IL-6, and pH value in the tracheal secretion were analyzed using standardized lab methods. RESULTS: The 50 patients admitted to the ICU with various diagnoses. The median survival time for the entire cohort was 52 days, and there was no significant difference in survival between patients with aspiration pneumonia (AP) and those with other diagnoses (p = 0.69). Among the AP group, the average survival time was 50.51 days (±8.1 SD; 95% CI 34.63-66.39), while patients with other diagnoses had a mean survival time of 32.86 days (±5.1 SD; 95% CI 22.9-42.81); the survival group comparison did not yield statistically significant results. The presence of pepsin or bile acid in TS patients did not significantly impact survival or the diagnosis of aspiration. The p-values for the correlations between pepsin and bile acid with the aspiration diagnosis were p = 0.53 and p > 0.99, respectively; thus, pepsin and bile acid measurements did not significantly affect survival outcomes or enhance the accuracy of diagnosing aspiration pneumonia. CONCLUSIONS: The early and accurate diagnosis of aspiration is crucial for optimal patient care. However, based on this study, pepsin concentration alone may not reliably indicate aspiration, and bile acid levels also show limited association with the diagnosis. Further validation studies are needed to assess the clinical usefulness and reliability of gastric biomarkers in diagnosing aspiration-related conditions. Such future studies would provide valuable insights for improving aspiration diagnosis and enhancing patient care.

Chronic Lung Allograft Dysfunction Is Associated with Increased Levels of Cell-Free Mitochondrial DNA in Bronchoalveolar Lavage Fluid of Lung Transplant Recipients.

Chronic Lung Allograft Dysfunction (CLAD) is a life-threatening complication that limits the long-term survival of lung transplantation patients. Early diagnosis remains the basis of efficient management of CLAD, making the need for distinctive biomarkers critical. This explorative study aimed to investigate the predictive power of mitochondrial DNA (mtDNA) derived from bronchoalveolar lavages (BAL) to detect CLAD. The study included 106 lung transplant recipients and analyzed 286 BAL samples for cell count, cell differentiation, and inflammatory and mitochondrial biomarkers, including mtDNA. A receiver operating curve analysis of mtDNA levels was used to assess its ability to detect CLAD. The results revealed a discriminatory pro-inflammatory cytokine profile in the BAL fluid of CLAD patients. The concentration of mtDNA increased in step with each CLAD stage, reaching its highest concentration in stage 4, and correlated significantly with decreasing FEV1. The receiver operating curve analysis of mtDNA in BAL revealed a moderate prediction of CLAD when all stages were grouped together (AUROC 0.75, p-value < 0.0001). This study has found the concentration mtDNA in BAL to be a potential predictor for the early detection of CLAD and the differentiation of different CLAD stages, independent of the underlying pathology.

Association of Clonal Hematopoiesis of Indeterminate Potential with Inflammatory Gene Expression in Patients with COPD.

Chronic obstructive pulmonary disease (COPD) is a disease with an inflammatory phenotype with increasing prevalence in the elderly. Expanded population of mutant blood cells carrying somatic mutations is termed clonal hematopoiesis of indeterminate potential (CHIP). The association between CHIP and COPD and its relevant effects on DNA methylation in aging are mainly unknown. Analyzing the deep-targeted amplicon sequencing from 125 COPD patients, we found enhanced incidence of CHIP mutations (~20%) with a predominance of DNMT3A CHIP-mediated hypomethylation of Phospholipase D Family Member 5 (PLD5), which in turn is positively correlated with increased levels of glycerol phosphocholine, pro-inflammatory cytokines, and deteriorating lung function.

Gamma-glutamyltransferase is a strong predictor of secondary sclerosing cholangitis after lung transplantation for COVID-19 ARDS.

BACKGROUND: Lung transplantation (LTx) can be considered for selected patients suffering from COVID-19 acute respiratory distress syndrome (ARDS). Secondary sclerosing cholangitis in critically ill (SSC-CIP) patients has been described as a late complication in COVID-19 ARDS survivors, however, rates of SSC-CIP after LTx and factors predicting this detrimental sequela are unknown. METHODS: This retrospective analysis included all LTx performed for post-COVID ARDS at 8 European LTx centers between May 2020 and January 2022. Clinical risk factors for SSC-CIP were analyzed over time. Prediction of SSC-CIP was assessed by ROC-analysis. RESULTS: A total of 40 patients were included in the analysis. Fifteen patients (37.5%) developed SSC-CIP. GGT at the time of listing was significantly higher in patients who developed SSC-CIP (median 661 (IQR 324-871) vs 186 (109-346); p = 0.001). Moreover, higher peak values for GGT (585 vs 128.4; p < 0.001) and ALP (325 vs 160.2; p = 0.015) were found in the 'SSC' group during the waiting period. Both, GGT at the time of listing and peak GGT during the waiting time, could predict SSC-CIP with an AUC of 0.797 (95% CI: 0.647-0.947) and 0.851 (95% CI: 0.707-0.995). Survival of 'SSC' patients was severely impaired compared to 'no SSC' patients (1-year: 46.7% vs 90.2%, log-rank p = 0.004). CONCLUSIONS: SSC-CIP is a severe late complication after LTx for COVID-19 ARDS leading to significant morbidity and mortality. GGT appears to be a sensitive parameter able to predict SSC-CIP even at the time of listing.

Relevance of Cor Pulmonale in COPD With and Without Pulmonary Hypertension: A Retrospective Cohort Study.

BACKGROUND: The relevance of cor pulmonale in COPD and pulmonary hypertension due to COPD (PH-COPD) is incompletely understood. We aimed to investigate the relationship of right ventricular-pulmonary arterial (RV-PA) uncoupling with disease severity in COPD, and the relationship of RV-PA uncoupling and use of targeted PH therapies with mortality in PH-COPD. METHODS: We retrospectively analyzed 231 patients with COPD without PH and 274 patients with PH-COPD. COPD was classified according to GOLD stages and the modified Medical Research Council dyspnoea scale. PH was categorized as mild-to-moderate or severe. RV-PA uncoupling was assessed as the echocardiographic tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) ratio. RESULTS: Of the cohort with COPD without PH, 21, 58, 54 and 92 were classified as GOLD I, II, III and IV, respectively. Patients in advanced GOLD stages and those with severe dyspnoea showed significantly decreased TAPSE/PASP.Of the PH-COPD cohort, 144 had mild-to-moderate PH and 130 had severe PH. During follow-up, 126 patients died. In univariate Cox regression, TAPSE/PASP and 6-min walk distance (6MWD; 10 m increments) predicted survival [hazard ratios (95% CI): 0.12 (0.03-0.57) and 0.95 (0.93-0.97), respectively]; notably, PH severity and simplified European Society of Cardiology/European Respiratory Society risk stratification did not. Among patients in the lowest or intermediate tertiles of TAPSE/PASP and 6MWD, those with targeted PH therapy had higher survival than those without (53 vs. 17% at 3 years). CONCLUSION: Cor pulmonale (decreased TAPSE/PASP and 6MWD) is associated with disease severity in COPD and predicts outcome in PH-COPD.

Extracorporeal Carbon Dioxide Removal Using a Renal Replacement Therapy Platform to Enhance Lung-Protective Ventilation in Hypercapnic Patients With Coronavirus Disease 2019-Associated Acute Respiratory Distress Syndrome.

Coronavirus disease 2019 (COVID-19)-associated acute respiratory distress syndrome (ARDS) is associated with high mortality. Lung-protective ventilation is the current standard of care in patients with ARDS, but it might lead to hypercapnia, which is independently associated with worse outcomes. Extracorporeal carbon dioxide removal (ECCO2R) has been proposed as an adjuvant therapy to avoid progression of clinical severity and limit further ventilator-induced lung injury, but its use in COVID-19 has not been described yet. Acute kidney injury requiring renal replacement therapy (RRT) is common among critically ill COVID-19 patients. In centers with available dialysis, low-flow ECCO2R (<500 mL/min) using RRT platforms could be carried out by dialysis specialists and might be an option to efficiently allocate resources during the COVID-19 pandemic for patients with hypercapnia as the main indication. Here, we report the feasibility, safety, and efficacy of ECCO2R using an RRT platform to provide either standalone ECCO2R or ECCO2R combined with RRT in four hypercapnic patients with moderate ARDS. A randomized clinical trial is required to assess the overall benefit and harm. Clinical Trial Registration: ClinicalTrials.gov. Unique identifier: NCT04351906.

Risk assessment in severe pulmonary hypertension due to interstitial lung disease.

BACKGROUND: The updated hemodynamic definition of pulmonary hypertension (PH) due to interstitial lung disease (ILD) differentiates severe and non-severe phenotypes, but no further risk stratification strategy has been established or validated for severe PH due to ILD. We aimed to assess the prognostic value of a truncated version of the European Society of Cardiology/European Respiratory Society (ESC/ERS) PH risk stratification scheme in severe PH due to ILD. METHODS: We retrospectively analyzed 185 patients with severe PH (mean pulmonary artery pressure of ≥35 mm Hg or ≥25 mm Hg with cardiac index <2.0 liter/min/m2) due to ILD who were enrolled in the Giessen PH Registry after being referred for invasive diagnostic work-up of suspected PH during 1995‒2018. A truncated ESC/ERS risk stratification scheme (based on 8 parameters from the full scheme) was applied. Kaplan-Meier and univariate Cox regression analyses were used to evaluate transplant-free survival and hazard ratios, respectively. RESULTS: During follow-up (median [interquartile range]: 19 [7-40] months), 146 events occurred. Using baseline data for risk stratification, 5-year transplant-free survival of low-, intermediate-, and high-risk groups was 43%, 15%, and 4%, respectively (log-rank p = 0.010; hazard ratio of high- vs low-risk group: 3.116 [95% CI: 1.428-6.800]). Using follow-up data (at 11 [6.0-32.5] months) for risk stratification, 5-year survival of low-, intermediate-, and high-risk groups was 22%, 3%, and 0%, respectively (log-rank p = 0.005). CONCLUSIONS: The truncated ESC/ERS scheme was clinically useful and demonstrated prognostic relevance in severe PH due to ILD.

SARS-CoV-2 infection in two patients following recent lung transplantation.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that causes coronavirus disease 2019 (COVID-19) has become a global health problem with pandemic character. Lung transplant recipients may be particularly at risk due to the high degree of immunosuppression and the lung being the organ primarily affected by COVID-19. We describe a 16-year-old male and a 64-year-old female recently lung transplanted patients with COVID-19 during inpatient rehabilitation. Both patients were receiving triple immunosuppressive therapy and had no signs of allograft dysfunction. Both patients had close contact with a person who developed COVID-19 and were tested positive for SARS-CoV-2. Subsequently, both patients underwent systematic screening and SARS-CoV-2 was ultimately detected. Although the 16-year-old boy was completely asymptomatic, the 64-year-old woman developed only mild COVID-19. Immunosuppressive therapy was unchanged and no experimental treatment was initiated. No signs of graft involvement or dysfunction were noticed. In conclusion, our report of patients with asymptomatic SARS-CoV-2 infection and mild COVID-19, respectively, may indicate that lung transplant recipients are not per se at risk for severe COVID-19. Further observations and controlled trials are urgently needed to study SARS-CoV-2 infection in lung transplant recipients.

Anti-interleukin-5 therapy (mepolizumab) in life-threatening asthma attack: A case-based discussion.

We report about a case of a compassionate off-label use of the anti-interleukin-5-agent mepolizumab in a ventilated patient with life-threatening asthma attack in eosinophilic asthma. The patient suffered from severe eosinophilic asthma and was transmitted to our hospital with an asthma attack and a life-threatening respiratory state under ventilation. Since high dose steroids had not yielded a sufficient respiratory improvement mepolizumab was administered subcutaneously. After administration of mepolizumab respiratory state and ventilation parameter improved significantly. Two days after administration the patient was weaned could be extubated 8 days later and recovered completely from the asthma attack. The presented clinical case is suggestive of future clinical trials or registry studies to evaluate potential clinical benefits of anti-interleukin-5 treatment in patients with severe exacerbations of eosinophilic asthma.

Indefinite cytomegalovirus prophylaxis with valganciclovir after lung transplantation.

Human cytomegalovirus (HCMV) infections and reactivations are common after lung transplantation and are associated with the development of bronchiolitis obliterans syndrome. Against this background, temporary HCMV prophylaxis is an established standard regimen after lung transplantation in most centers. However, the optimal duration of prophylaxis is unclear. We conducted a retrospective two-center study to determine the efficacy of indefinite lifelong HCMV prophylaxis with oral valganciclovir in a cohort of 133 lung transplant recipients with a mean follow-up time of approximately 5 years. During the follow-up period, HCMV DNA was detected in 22 recipients (16.5%). In one case, HCMV pneumonitis developed after prophylaxis had been terminated. We observed a beneficial safety profile and tolerability in our cohort, as the majority of patients still received valganciclovir after a 1- and 3-year observation period, respectively. Compared to the literature, these data indicate a beneficial effect of extended valganciclovir prophylaxis with an acceptable safety profile.

Riociguat for treatment of pulmonary hypertension in COPD: a translational study.

Chronic obstructive pulmonary disease (COPD), which comprises the phenotypes of chronic bronchitis and emphysema, is often associated with pulmonary hypertension (PH). However, currently, no approved therapy exists for PH-COPD. Signalling of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) axis plays an important role in PH and COPD.We investigated the treatment effect of riociguat, which promotes the NO-cGMP pathway, in the mouse model of smoke-induced PH and emphysema in a curative approach, and retrospectively analysed the effect of riociguat treatment on PH in single patients with PH-COPD.In mice with established PH and emphysema (after 8 months of cigarette smoke exposure), riociguat treatment for another 3 months fully reversed PH. Moreover, histological hallmarks of emphysema were decreased. Microarray analysis revealed involvement of different signalling pathways, e.g. related to matrix metalloproteinases (MMPs). MMP activity was decreased in vivo by riociguat. In PH-COPD patients treated with riociguat (n=7), the pulmonary vascular resistance, airway resistance and circulating MMP levels decreased, while oxygenation at rest was not significantly changed.Riociguat may be beneficial for treatment of PH-COPD. Further long-term prospective studies are necessary to investigate the tolerability, efficacy on functional parameters and effect specifically on pulmonary emphysema in COPD patients.

Use of very old donors for lung transplantation: a dual-centre retrospective analysis.

OBJECTIVES: To reduce the shortage of organs for transplantation by expanding organ selection criteria as a means to increase the pool of potential lung donors. In this study, we sought to investigate the impact of using lungs from very old donors aged >70 years on outcomes after lung transplantation. METHODS: Between January 2010 and November 2016, 96 patients with end-stage lung disease underwent lung transplantation in our centres. Lung donors were divided into 3 groups according to age (donor aged <60 years, 60-69 years and ≥70 years). We examined the effect of donor age on various short- and long-term outcome parameters. RESULTS: Lungs harvested from very old donors had a lower percentage of smoking history and shorter ventilation time. Survival rates of recipients did not show significant differences between older and younger donor groups. Most of the short- and long-term outcome parameters in recipients of lungs from very old donors did not differ significantly among the 3 age groups, except for post-transplant best forced expiratory volume in 1 s and treated acute rejections, which were lower and higher, respectively, in donors aged ≥70 years. CONCLUSIONS: This dual-centre analysis showed that lung transplantation from donors aged ≥70 years was not associated with worse outcomes compared with the younger donors. This study supports the idea that it might be possible to use an extraordinarily cautious selection of lungs from very old donors to increase the pool of suitable donors, given the shortage of suitable organ donors available for lung transplantation.

Early neurovascular uncoupling in the brain during community acquired pneumonia.

INTRODUCTION: Sepsis leads to microcirculatory dysfunction and therefore a disturbed neurovascular coupling in the brain. To investigate if the dysfunction is also present in less severe inflammatory diseases we studied the neurovascular coupling in patients suffering from community acquired pneumonia. METHODS: Patients were investigated in the acute phase of pneumonia and after recovery. The neurovascular coupling was investigated with a simultaneous electroencephalogram (EEG)-Doppler technique applying a visual stimulation paradigm. Resting EEG frequencies, visual evoked potentials as well as resting and stimulated hemodynamic responses were obtained. Disease severity was characterized by laboratory and cognitive parameters as well as related scoring systems. Data were compared to a control group. RESULTS: Whereas visually evoked potentials (VEP) remained stable a significant slowing and therefore uncoupling of the hemodynamic responses were found in the acute phase of pneumonia (Rate time: control group: 3.6 ± 2.5 vs. acute pneumonia: 1.6 ± 2.4 s; P < 0.0005). In the initial investigation, patients who deteriorated showed a decreased hemodynamic response as compared with those who recovered (gain: recovered: 15% ± 4% vs. deteriorated: 9% ± 3%, P < 0.05; control: 14% ± 5%). After recovery the coupling normalized. CONCLUSIONS: Our study underlines the role of an early microcirculatory dysfunction in inflammatory syndromes that become evident in pre-septic conditions with a gradual decline according to disease severity.