Alveolar macrophage lipid burden correlates with clinical improvement in patients with pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a life-threatening, rare lung syndrome for which there is no cure and no approved therapies. PAP is a disease of lipid accumulation characterized by alveolar macrophage foam cell formation. While much is known about the clinical presentation, there is a paucity of information regarding temporal changes in lipids throughout the course of disease. Our objectives were to define the detailed lipid composition of alveolar macrophages in PAP patients at the time of diagnosis and during treatment. We performed comprehensive mass spectrometry to profile the lipid signature of alveolar macrophages obtained from three independent mouse models of PAP and from PAP and non-PAP patients. Additionally, we quantified changes in macrophage-associated lipids during clinical treatment of PAP patients. We found remarkable variations in lipid composition in PAP patients, which were consistent with data from three independent mouse models. Detailed lipidomic analysis revealed that the overall alveolar macrophage lipid burden inversely correlated with clinical improvement and response to therapy in PAP patients. Specifically, as PAP patients experienced clinical improvement, there was a notable decrease in the total lipid content of alveolar macrophages. This crucial observation suggests that the levels of these macrophage-associated lipids can be utilized to assess the efficacy of treatment. These findings provide valuable insights into the dysregulated lipid metabolism associated with PAP, offering the potential for lipid profiling to serve as a means of monitoring therapeutic interventions in PAP patients.

Anti-Granulocyte-Macrophage Colony-Stimulating Factor Monoclonal Antibody Gimsilumab for COVID-19 Pneumonia: A Randomized, Double-Blind, Placebo-controlled Trial.

Rationale: GM-CSF (granulocyte-macrophage colony-stimulating factor) has emerged as a promising target against the hyperactive host immune response associated with coronavirus disease (COVID-19). Objectives: We sought to investigate the efficacy and safety of gimsilumab, an anti-GM-CSF monoclonal antibody, for the treatment of hospitalized patients with elevated inflammatory markers and hypoxemia secondary to COVID-19. Methods: We conducted a 24-week randomized, double-blind, placebo-controlled trial, BREATHE (Better Respiratory Education and Treatment Help Empower), at 21 locations in the United States. Patients were randomized 1:1 to receive two doses of intravenous gimsilumab or placebo 1 week apart. The primary endpoint was all-cause mortality rate at Day 43. Key secondary outcomes were ventilator-free survival rate, ventilator-free days, and time to hospital discharge. Enrollment was halted early for futility based on an interim analysis. Measurements and Main Results: Of the planned 270 patients, 225 were randomized and dosed; 44.9% of patients were Hispanic or Latino. The gimsilumab and placebo groups experienced an all-cause mortality rate at Day 43 of 28.3% and 23.2%, respectively (adjusted difference = 5% vs. placebo; 95% confidence interval [-6 to 17]; P = 0.377). Overall mortality rates at 24 weeks were similar across the treatment arms. The key secondary endpoints demonstrated no significant differences between groups. Despite the high background use of corticosteroids and anticoagulants, adverse events were generally balanced between treatment groups. Conclusions: Gimsilumab did not improve mortality or other key clinical outcomes in patients with COVID-19 pneumonia and evidence of systemic inflammation. The utility of anti-GM-CSF therapy for COVID-19 remains unclear. Clinical trial registered with www.clinicaltrials.gov (NCT04351243).

Postoperative Trapped Lung After Orthotopic Liver Transplantation is a Predictor of Increased Mortality.

Pleural effusions are a common complication of orthotopic liver transplantation (OLT), and chronic post-OLT pleural effusions have been associated with worse outcomes. Furthermore, "trapped lung" (TL), defined as a restrictive fibrous visceral pleural peel preventing lung re-expansion, may have prognostic significance. We performed a retrospective analysis of adult OLT recipients over a 9-year period at UCLA Medical Center. Post-OLT patients with persistent pleural effusions, defined by the presence of pleural fluid requiring drainage one to 12 months after OLT, were included for analysis. Outcomes for patients with and without TL were compared using univariate and multivariate analysis. Of the 1722 patients who underwent OLT, 117 (7%) patients met our criteria for persistent postoperative pleural effusion, and the incidence of TL was 21.4% (25/117). Compared to patients without TL, those with TL required more surgical pleural procedures (OR 59.8, 95%CI 19.7-181.4, p < 0.001), spent more days in the hospital (IRR 1.56, 95%CI 1.09-2.23, p = 0.015), and had a higher risk of mortality (HR 2.47, 95%CI 1.59-3.82, p < 0.001) following transplant. In sum, we found that post-OLT TL was associated with higher morbidity, mortality, and healthcare utilization. Future prospective investigation is warranted to further clarify the risk factors for developing postoperative pleural effusions and TL.

Survival After Severe COVID-19: Long-Term Outcomes of Patients Admitted to an Intensive Care Unit.

BACKGROUND: Understanding the long-term sequelae of severe COVID-19 remains limited, particularly in the United States. OBJECTIVE: To examine long-term outcomes of patients who required intensive care unit (ICU) admission for severe COVID-19. DESIGN, PATIENTS, AND MAIN MEASURES: This is a prospective cohort study of patients who had severe COVID-19 requiring an ICU admission in a two-hospital academic health system in Southern California. Patients discharged alive between 3/21/2020 and 12/31/2020 were surveyed approximately 6 months after discharge to assess health-related quality of life using Patient-Reported Outcomes Measurement Information System (PROMIS®)-29 v2.1, post-traumatic stress disorder (PTSD) and loneliness scales. A preference-based health utility score (PROPr) was estimated using 7 PROMIS domain scores. Patients were also asked their attitude about receiving aggressive ICU care. KEY RESULTS: Of 275 patients admitted to the ICU for severe COVID-19, 205 (74.5%) were discharged alive and 132 (64%, median age 59, 46% female) completed surveys a median of 182 days post-discharge. Anxiety, depression, fatigue, sleep disturbance, ability to participate in social activities, pain interference, and cognitive function were not significantly different from the U.S. general population, but physical function (44.2, SD 11.0) was worse. PROPr mean score of 0.46 (SD 0.30, range -0.02 to 0.96 [<0 is worse than dead and 1 represents perfect health]) was slightly lower than the U.S. general population, with an even distribution across the continuum. Poor PROPr was associated with chronic medical conditions and receipt of life-sustaining treatments, but not demographics or social vulnerability. PTSD was suspected in 20% and loneliness in 29% of patients. Ninety-eight percent of patients were glad they received life-saving treatment. CONCLUSION: Most patients who survive severe COVID-19 achieve positive outcomes, with health scores similar to the general population at 6 months post-discharge. However, there is marked heterogeneity in outcomes with a substantial minority reporting severely compromised health.

Characteristics of hospital admissions for pulmonary alveolar proteinosis: analysis of the nationwide inpatient sample (2012-2014).

BACKGROUND: Pulmonary alveolar proteinosis (PAP) is a rare clinical syndrome involving the accumulation of lipid-rich proteinaceous material in the alveoli. There is a paucity of published studies on this condition. To better characterize the demographics, complication rates, mortality, and healthcare costs of patients hospitalized for PAP in the United States, a secondary analysis on the Hospital Cost and Utilization Project's Nationwide Inpatient Sample (NIS) was performed on patients admitted from 2012 to 2014 with a diagnosis of pulmonary alveolar proteinosis. METHODS: Using the NIS database, a secondary analysis was performed on 500 admissions with the diagnosis "pulmonary alveolar proteinosis." The clinical variables and outcome measures extracted were: patient demographics, hospital costs, length of stay, frequency of admissions, and inpatient mortality rate. RESULTS: Among a weighted estimate of 500 hospital admissions from 2012 to 2014, the number of PAP admissions averaged 4.7 per million. The population was predominantly male (55%) with a mean age of 41.45 (CI 38.3-44.5) from all socioeconomic levels. Inpatient mortality was calculated to be 5%, which may result from the fact that the majority of admitted patients had few or no comorbid conditions (CCI 0.72). The most common procedure performed during admission was a bronchoalveolar lavage. Mean length of stay was 6.2 days (CI 3.9-8.5) and average cost of admission was $29,932.20 (CI 13,739-46,124). Of note, 50% of these admissions were considered "elective." CONCLUSIONS: Demographics of patients with PAP who have been hospitalized in the United States are similar to previously reported demographics from prior patient cohorts, specifically a male predominance and a mean age in the 40 s. The inpatient mortality rate of 5% we found is consistent with prior studies demonstrating good disease-specific survival rates. Notably, the cost per admission and overall annual cost associated with PAP hospitalization was calculated to be $29932.20 and $5 million respectively. This reflects the high economic cost associated with hospitalization of PAP patients, and provokes thought about ways to make treatment more cost-effective.

Ultrasound Assessment of the Change in Carotid Corrected Flow Time in Fluid Responsiveness in Undifferentiated Shock.

OBJECTIVES: Adequate assessment of fluid responsiveness in shock necessitates correct interpretation of hemodynamic changes induced by preload challenge. This study evaluates the accuracy of point-of-care Doppler ultrasound assessment of the change in carotid corrected flow time induced by a passive leg raise maneuver as a predictor of fluid responsiveness. Noninvasive cardiac output monitoring (NICOM, Cheetah Medical, Newton Center, MA) system based on a bioreactance method was used. DESIGN: Prospective, noninterventional study. SETTING: ICU at a large academic center. PATIENTS: Patients with new, undifferentiated shock, and vasopressor requirements despite fluid resuscitation were included. Patients with significant cardiac disease and conditions that precluded adequate passive leg raising were excluded. INTERVENTIONS: Carotid corrected flow time was measured via ultrasound before and after a passive leg raise maneuver. Predicted fluid responsiveness was defined as greater than 10% increase in stroke volume on noninvasive cardiac output monitoring following passive leg raise. Images and measurements were reanalyzed by a second, blinded physician. The accuracy of change in carotid corrected flow time to predict fluid responsiveness was evaluated using receiver operating characteristic analysis. MEASUREMENTS AND MAIN RESULTS: Seventy-seven subjects were enrolled with 54 (70.1%) classified as fluid responders by noninvasive cardiac output monitoring. The average change in carotid corrected flow time after passive leg raise for fluid responders was 14.1 ± 18.7 ms versus -4.0 ± 8 ms for nonresponders (p < 0.001). Receiver operating characteristic analysis demonstrated that change in carotid corrected flow time is an accurate predictor of fluid responsiveness status (area under the curve, 0.88; 95% CI, 0.80-0.96) and a 7 ms increase in carotid corrected flow time post passive leg raise was shown to have a 97% positive predictive value and 82% accuracy in detecting fluid responsiveness using noninvasive cardiac output monitoring as a reference standard. Mechanical ventilation, respiratory rate, and high positive end-expiratory pressure had no significant impact on test performance. Post hoc blinded evaluation of bedside acquired measurements demonstrated agreement between evaluators. CONCLUSIONS: Change in carotid corrected flow time can predict fluid responsiveness status after a passive leg raise maneuver. Using point-of-care ultrasound to assess change in carotid corrected flow time is an acceptable and reproducible method for noninvasive identification of fluid responsiveness in critically ill patients with undifferentiated shock.

Acute Respiratory Failure and Pulmonary Complications in End-Stage Liver Disease.

Acute respiratory failure has a high mortality in patients with end-stage liver disease (ESLD). These patients may develop acute respiratory failure for reasons specific to advanced liver disease, including hepatopulmonary syndrome, portopulmonary hypertension, and hepatic hydrothorax. They may also develop respiratory complications due to conditions seen in the general intensive care unit population to which ESLD patients are at higher risk, including infection, volume overload, and the acute respiratory distress syndrome. Management of these patients is complicated and multifaceted, and a comprehensive understanding of the etiologies and treatment of acute respiratory failure is critical in this high-risk patient population. This article reviews current evidence surrounding the prevalence, management, and complications of the various etiologies of acute respiratory failure in ESLD patients.

Perioperative Considerations in Liver Transplantation.

Liver transplantation (LT) has the potential to cure patients with acute and chronic liver failure as well as a number of hepatic and biliary malignancies. Over time, due to the increasing demand for organs as well as improvements in the survival of LT recipients, patients awaiting LT have become sicker, and often undergo the procedure while critically ill. This trend has made the process of preoperative assessment and planning, intraoperative management, and postoperative management even more crucial to the success of LT programs. Multidisciplinary and specialized teams are essential and include anesthesiologists, surgeons, and intensivists. This article focuses on the preoperative evaluation, intraoperative care, and postoperative management of the liver transplant patient. Management relevant to the critically ill patient is discussed, with a focus on the management of postoperative cardiopulmonary conditions including the care of special populations such as those with hepatopulmonary syndrome and portopulmonary hypertension.

ABCG1 regulates pulmonary surfactant metabolism in mice and men.

Idiopathic pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by accumulation of surfactant. Surfactant synthesis and secretion are restricted to epithelial type 2 (T2) pneumocytes (also called T2 cells). Clearance of surfactant is dependent upon T2 cells and macrophages. ABCG1 is highly expressed in both T2 cells and macrophages. ABCG1-deficient mice accumulate surfactant, lamellar body-loaded T2 cells, lipid-loaded macrophages, B-1 lymphocytes, and immunoglobulins, clearly demonstrating that ABCG1 has a critical role in pulmonary homeostasis. We identify a variant in the ABCG1 promoter in patients with PAP that results in impaired activation of ABCG1 by the liver X receptor α, suggesting that ABCG1 basal expression and/or induction in response to sterol/lipid loading is essential for normal lung function. We generated mice lacking ABCG1 specifically in either T2 cells or macrophages to determine the relative contribution of these cell types on surfactant lipid homeostasis. These results establish a critical role for T2 cell ABCG1 in controlling surfactant and overall lipid homeostasis in the lung and in the pathogenesis of human lung disease.

Prognostic significance of infections in critically ill adult patients with acute liver injury: a retrospective cohort study.

BACKGROUND AND AIMS: Patients with acute liver failure have high rates of infections, likely from defects in immune function. Whether infections are independently associated with poor outcomes is unclear. We hypothesized that patients with acute liver injury who developed infections were at increased risk of adverse outcomes. METHODS: We conducted a retrospective analysis of 150 critically ill adult patients admitted with acute liver dysfunction at a single academic institution between 2005 and 2011. We excluded patients with immunocompromised states, patients with chronic liver disease and patients who died or were discharged within 48 h of admission. Our primary endpoint was a 30-day event-free survival, with events defined as either death or liver transplantation. Our secondary endpoint was length of stay. Univariate and multivariate analyses were performed to determine associations between presence of infection and our primary and secondary endpoints. RESULTS: Of our cohort of 150 patients, 62 (41%) were infected and 88 (59%) were not infected. Of the infected patients, 45% died or underwent transplantation, compared to 22% for the non-infected patients (P = 0.003). Univariate and multivariate analyses demonstrated that infections in patients with acute liver dysfunction were an independent predictor of poor outcome (i.e. death or transplantation). In addition, specific types of infection, including pneumonia, independently led to a 48% increase in length of stay (P = 0.002). CONCLUSIONS: Infections in patients with acute liver dysfunction are associated with increased risk of death or transplant and increased hospital length of stay.

A narrative review: The effects of opioids on sleep disordered breathing in chronic pain patients and methadone maintained patients.

BACKGROUND AND OBJECTIVES: Opioids increase the risk for sleep disordered breathing (SDB), but there are few studies examining the prevalence and risk factors for SDB, specifically central sleep apnea (CSA), and obstructive sleep apnea (OSA) in chronic pain patients on opioids as well as methadone maintained patients (MMPs). METHODS: A literature review was conducted in which SDB was confirmed by polysomnography (PSG) in chronic pain patients on opioids as well as patients with a diagnosis of an opioid use disorder or opioid dependence on methadone maintenance treatment (MMT). RESULTS: About 22 reports were included. Six were with MMPs, and 16 were with chronic pain patients on opioids. Among MMPs, the prevalence of SDB ranged from 42.3% to 70%; 0-60% had CSA and 10-35.2% had OSA. In chronic pain patients on opioids, the prevalence of SDB ranged from 71% to 100%; 17-80% had CSA and 20-39% had OSA. In MMPs, studies found a positive association between BMI, weight gain, duration of MMT, non-Caucasian race and the number of obstructive apneas, as well as blood methadone concentrations and the number of central apneas. In chronic pain patients on opioids, older age, higher BMI, male gender, and higher opioid doses predicted more obstructive apneas; older age, lower BMI, male gender, higher pain levels, higher benzodiazepine doses, and higher opioid doses predicted more central apneas. CONCLUSION AND SCIENTIFIC SIGNIFICANCE: CSA and OSA are common in MMPs and chronic pain patients on opioids. Among chronic pain patients, higher opioid doses appear to be a risk factor for CSA, and to a lesser extent OSA. Therefore, it is important for providers to screen these patient populations for SDB. (Am J Addict 2016;25:452-465).

A plasmapheresis protocol for refractory pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare lung disease characterized by the accumulation of proteinaceous material within the lungs. While typically managed with whole lung lavage (WLL), more recent PAP therapies aimed at reducing granulocyte-macrophage colony stimulating factor autoantibodies (anti-GM-CSF) have reduced symptoms and improved lung function. We present a patient with PAP refractory to WLL, exogenous GM-CSF and rituximab who underwent a novel plasmapheresis protocol as a therapeutic trial. While previously reported regimens have utilized plasmapheresis sessions distributed over months, our patient underwent five consecutive days of plasmapheresis, followed by rituximab. Anti-GM-CSF levels decreased from 24.8 to 2.7 mcg/mL post-plasmapheresis. This reduction of autoantibody correlated with reduction in WLL frequency, increase in diffusing capacity for carbon monoxide, and subjective improvement in dyspnea. Our case suggests that five consecutive days of plasmapharesis results in increased clearance of anti-GM-CSF and may be potentially efficacious in cases of refractory PAP.

Subsequent infections in survivors of sepsis: epidemiology and outcomes.

PURPOSE: Sepsis is a devastating condition with considerable mortality. The causes of long-term mortality are poorly understood. To test the hypothesis that patients with sepsis are more susceptible to recurrent infections and death due to infectious complications, we investigated the outcomes of patients who survived sepsis, with regard to the incidence of recurrent infections and mortality. MATERIALS AND METHODS: A retrospective study of the patients admitted to the intensive care unit (ICU) for sepsis from 2001 to 2002 who achieved 30-day survival (sepsis survivors [SSs], N = 78) and a control group of patients admitted to the ICU for noninfectious conditions with a similar severity of illness (N = 50) was performed. The primary end point was the number of recurrent infections in the first year posthospitalization. RESULTS: The SSs group had higher rates of infections following hospital discharge compared to controls. Using a multivariable model, having survived sepsis was the strongest predictor of the development of subsequent infections (rate ratio [RR]: 2.83, P= .0006), the need for rehospitalization for infection in the year after the initial hospitalization (RR: 3.78, P = .0009), and postdischarge mortality (hazard ratio = 3.61, P = .003). CONCLUSIONS: Critically ill patients who survive sepsis have an increased risk of recurrent infections in the year following their septic episode that is associated with increased mortality.

A rare occurrence of pulmonary alveolar proteinosis after lung transplantation.

We present a case of pulmonary alveolar proteinosis (PAP) initially diagnosed 28 months after left single-lung transplantation for idiopathic pulmonary fibrosis. The diagnosis was based upon the presence of periodic acid-Schiff (PAS)-positive and surfactant immunostain-positive acellular lipoproteinaceous material within alveoli seen on transbronchial biopsy as well as in bronchoalveolar lavage fluid. The patient eventually also displayed a characteristic "crazy paving" pattern on radiographic imaging. Granulocyte macrophage-colony stimulating factor antibodies were negative, consistent with secondary PAP. PAP is a rare interstitial lung disease with only a few reported cases occurring after lung transplantation. The etiology is thought to be related to a defect in macrophage function caused by immunosuppression. Reduced immunosuppression has been associated with stabilization, but not reversal, of the condition in the case reported here. PAP is an exceptionally rare cause of dyspnea and radiographic infiltrates after lung transplantation and may be related to toxicity of immune-suppressive medications.

Implications of Pleural Fluid Composition in Persistent Pleural Effusion following Orthotopic Liver Transplant.

Persistent pleural effusions (PPEf) represent a known complication of orthotopic liver transplant (OLT). However, their clinical relevance is not well described. We evaluated the clinical, biochemical, and cellular characteristics of post-OLT PPEf and assessed their relationship with longitudinal outcomes. We performed a retrospective cohort study of OLT recipients between 2006 and 2015. Included patients had post-OLT PPEf, defined by effusion persisting >30 days after OLT and available pleural fluid analysis. PPEf were classified as transudates or exudates (ExudLight) by Light's criteria. Exudates were subclassified as those with elevated lactate dehydrogenase (ExudLDH) or elevated protein (ExudProt). Cellular composition was classified as neutrophil- or lymphocyte-predominant. Of 1602 OLT patients, 124 (7.7%) had PPEf, of which 90.2% were ExudLight. Compared to all OLT recipients, PPEf patients had lower two-year survival (HR 1.63; p = 0.002). Among PPEf patients, one-year mortality was associated with pleural fluid RBC count (p = 0.03). While ExudLight and ExudProt showed no association with outcomes, ExudLDH were associated with increased ventilator dependence (p = 0.03) and postoperative length of stay (p = 0.03). Neutrophil-predominant effusions were associated with increased postoperative ventilator dependence (p = 0.03), vasopressor dependence (p = 0.02), and surgical pleural intervention (p = 0.02). In summary, post-OLT PPEf were associated with increased mortality. Ninety percent of these effusions were exudates by Light's criteria. Defining exudates using LDH only and incorporating cellular analysis, including neutrophils and RBCs, was useful in predicting morbidity.

Pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis (PAP) is a rare disorder characterized by the accumulation of surfactant lipids and protein in the alveolar spaces, with resultant impairment in gas exchange. The clinical course can be variable, ranging from spontaneous resolution to respiratory failure and death. PAP in all forms is caused by excessive accumulation of surfactant within the alveolar spaces. Autoimmune PAP accounts for the vast majority of cases in humans and is caused by autoantibodies to granulocyte-macrophage colony-stimulating factor (GM-CSF), which results in impaired catabolism and clearance of surfactant lipids and proteins. Inherited or congenital forms of PAP are exceptionally rare and caused by mutations of genes encoding for surfactant proteins. Secondary forms of PAP are associated with diverse clinical disorders and are caused by reduced alveolar macrophage numbers or function with resultant reduced pulmonary clearance of surfactant. PAP is characterized by progressive exertional dyspnea and nonproductive cough with hypoxemia. Bilateral infiltrates are typically present on chest radiograph, and high-resolution computed tomography reveals diffuse ground-glass opacities and airspace consolidation with interlobular septal thickening in a characteristic "crazy paving" pattern. Although surgical lung biopsy will provide a definitive diagnosis, a combination of typical clinical and imaging features with periodic acid-Schiff (PAS)-positive material on bronchoalveolar lavage and transbronchial biopsies is usually sufficient. The standard of care for treatment of PAP remains whole lung lavage, but treatment is not required in all patients. Autoimmune PAP has also been successfully treated with GM-CSF, both inhaled and systemic, but the optimal dose, duration, and route of administration of GM-CSF have not been elucidated.

Sleep disorders in chronic liver disease.

Sleep-related complaints and disturbances are increasingly recognized in the setting of chronic liver disease and have recently been shown to be an important prognostic factor in patients with advanced chronic liver disease. This article reviews the literature surrounding sleep disturbances and disorders in a variety of types of chronic liver disease. This includes the association of sleep disturbances with hepatitis C and antiviral therapy, primary biliary cirrhosis, and Wilson disease as well as the circadian rhythm abnormalities present in cirrhosis and hepatic encephalopathy. The association between chronic liver disease, particularly nonalcoholic fatty liver disease, and sleep-disordered breathing is also reviewed in detail.