Anthony F. Massaro

Inflammasome-regulated Cytokines Are Critical Mediators of Acute Lung Injury

RATIONALE Despite advances in clinical management, there are currently no reliable diagnostic and therapeutic targets for acute respiratory distress syndrome (ARDS). The inflammasome/caspase-1 pathway regulates the maturation and secretion of proinflammatory cytokines (e.g., IL-18). IL-18 is associated with injury in animal models of systemic inflammation. OBJECTIVES We sought to determine the contribution of the inflammasome pathway in experimental acute lung injury and human ARDS. METHODS We performed comprehensive gene expression profiling on peripheral blood from patients with critical illness. Gene expression changes were assessed using real-time polymerase chain reaction, and IL-18 levels were measured in the plasma of the critically ill patients. Wild-type mice or mice genetically deficient in IL-18 or caspase-1 were mechanically ventilated using moderate tidal volume (12 ml/kg). Lung injury parameters were assessed in lung tissue, serum, and bronchoalveolar lavage fluid. MEASUREMENTS AND MAIN RESULTS In mice, mechanical ventilation enhanced IL-18 levels in the lung, serum, and bronchoalveolar lavage fluid. IL-18-neutralizing antibody treatment, or genetic deletion of IL-18 or caspase-1, reduced lung injury in response to mechanical ventilation. In human patients with ARDS, inflammasome-related mRNA transcripts (CASP1, IL1B, and IL18) were increased in peripheral blood. In samples from four clinical centers, IL-18 was elevated in the plasma of patients with ARDS (sepsis or trauma-induced ARDS) and served as a novel biomarker of intensive care unit morbidity and mortality. CONCLUSIONS The inflammasome pathway and its downstream cytokines play critical roles in ARDS development.

Intensive communication: four-year follow-up from a clinical practice study.

PurposeTo determine the durability of the effects of a change in practice designed to promote the use of advanced supportive technology when it is of benefit but to limit its burdens when it is ineffective. We have reported that institution of a process of intensive communication reduced length of intensive care unit stay for dying patients and reduced mortality in a before-and-after study in a cohort of patients admitted to an adult intensive care unit. We now report the results of a 4-yr extension of this intervention. Materials and MethodsThe number of counseling sessions, intensive care unit length of stay, and mortality were measured for 2,361 adult medical patients consecutively admitted to a university tertiary care hospital. To determine the durability of the effects of our intervention, we compared our experience during the subsequent 4 yrs with that of the 134 consecutive patients before and 396 patients after our intensive communication intervention. ResultsWe conducted an equivalent number of intensive communication sessions in our subsequent practice as during the intervention (1.5 vs. 1.6 sessions per patient admitted to the intensive care unit). However, sessions tended to be of shorter duration, and direct participation by social workers, chaplains, and care coordinators was less frequent in our subsequent experience. Intensive communication produced a significant and durable reduction in length of stay (median length of stay, 4 days [2–11 days, interquartile range] before; 3 days [2–6 days, interquartile range] during the study; 3 days [2–6 days, interquartile range] subsequently). Our intervention was associated with a significant and durable reduction in intensive care unit mortality (31.3% before, 22.7% during the intervention, 18% subsequently;p < .001). ConclusionsIntensive communication is associated with durable reductions in intensive care unit length of stay and reduced mortality in critically ill adult medical patients. Intensive communication was applied more efficiently subsequent to the intervention, and its effectiveness does not seem to be dependent on nondirect caregivers’ participation in the sessions. This process encourages the continuation of advanced supportive technology to patients with the potential to survive and allows the earlier withdrawal of advanced supportive technology when it is ineffective.

Sepsis: An integrated clinico-metabolomic model improves prediction of death in sepsis

A molecular signature, derived from integrated analysis of clinical data, the metabolome, and the proteome in prospective human studies, improved the prediction of death in patients with sepsis, potentially identifying a subset of patients who merit intensive treatment. Understanding Survival of the Fittest in Sepsis Differentiating mild infections from life-threatening ones is a complex decision that is made millions of times a year in U.S. emergency rooms. Should a patient be sent home with antibiotics and chicken soup? Or should he or she be hospitalized for intensive treatment? Sepsis—a serious infection that is associated with a generalized inflammatory response—is one of the leading causes of death. In two prospective clinical studies reported by Langley et al., patients arriving at four urban emergency departments with symptoms of sepsis were evaluated clinically and by analysis of their plasma proteome and metabolome. Survivors and nonsurvivors at 28 days were compared, and a molecular signature was detected that appeared to differentiate these outcomes—even as early as the time of hospital arrival. The signature was part of a large set of differences between these groups, showing that better energy-producing fatty acid catabolism was associated with survival of the fittest in sepsis. A test developed from the signature was able to predict sepsis survival and nonsurvival reproducibly and better than current methods. This test could help to make all important decisions in the emergency room more accurate. Sepsis is a common cause of death, but outcomes in individual patients are difficult to predict. Elucidating the molecular processes that differ between sepsis patients who survive and those who die may permit more appropriate treatments to be deployed. We examined the clinical features and the plasma metabolome and proteome of patients with and without community-acquired sepsis, upon their arrival at hospital emergency departments and 24 hours later. The metabolomes and proteomes of patients at hospital admittance who would ultimately die differed markedly from those of patients who would survive. The different profiles of proteins and metabolites clustered into the following groups: fatty acid transport and β-oxidation, gluconeogenesis, and the citric acid cycle. They differed consistently among several sets of patients, and diverged more as death approached. In contrast, the metabolomes and proteomes of surviving patients with mild sepsis did not differ from survivors with severe sepsis or septic shock. An algorithm derived from clinical features together with measurements of five metabolites predicted patient survival. This algorithm may help to guide the treatment of individual patients with sepsis.

Circulating Mitochondrial DNA in Patients in the ICU as a Marker of Mortality: Derivation and Validation

In this paper, Choi and colleagues analyzed levels of mitochondrial DNA in two prospective observational cohort studies and found that increased mtDNA levels are associated with ICU mortality, and improve risk prediction in medical ICU patients. The data suggests that mtDNA could serve as a viable plasma biomarker in MICU patients.

Integrative "omic" analysis of experimental bacteremia identifies a metabolic signature that distinguishes human sepsis from systemic inflammatory response syndromes.

RATIONALE Sepsis is a leading cause of morbidity and mortality. Currently, early diagnosis and the progression of the disease are difficult to make. The integration of metabolomic and transcriptomic data in a primate model of sepsis may provide a novel molecular signature of clinical sepsis. OBJECTIVES To develop a biomarker panel to characterize sepsis in primates and ascertain its relevance to early diagnosis and progression of human sepsis. METHODS Intravenous inoculation of Macaca fascicularis with Escherichia coli produced mild to severe sepsis, lung injury, and death. Plasma samples were obtained before and after 1, 3, and 5 days of E. coli challenge and at the time of killing. At necropsy, blood, lung, kidney, and spleen samples were collected. An integrative analysis of the metabolomic and transcriptomic datasets was performed to identify a panel of sepsis biomarkers. MEASUREMENTS AND MAIN RESULTS The extent of E. coli invasion, respiratory distress, lethargy, and mortality was dependent on the bacterial dose. Metabolomic and transcriptomic changes characterized severe infections and death, and indicated impaired mitochondrial, peroxisomal, and liver functions. Analysis of the pulmonary transcriptome and plasma metabolome suggested impaired fatty acid catabolism regulated by peroxisome-proliferator activated receptor signaling. A representative four-metabolite model effectively diagnosed sepsis in primates (area under the curve, 0.966) and in two human sepsis cohorts (area under the curve, 0.78 and 0.82). CONCLUSIONS A model of sepsis based on reciprocal metabolomic and transcriptomic data was developed in primates and validated in two human patient cohorts. It is anticipated that the identified parameters will facilitate early diagnosis and management of sepsis.

Exhaled nitric oxide: a marker of pulmonary hemodynamics in heart failure.

OBJECTIVES We sought to test the hypothesis that patients with decompensated heart failure (HF) lose a compensatory process whereby nitric oxide (NO) maintains pulmonary vascular tone. BACKGROUND Exhaled nitric oxide (eNO) partially reflects vascular endothelial NO release. Levels of eNO are elevated in patients with compensated HF and correlate inversely with pulmonary artery pressures (PAP), reflecting pulmonary vasodilatory activity. METHODS We measured the mean mixed expired NO content of a vital-capacity breath using chemiluminescence in patients with compensated HF (n = 30), decompensated HF (n = 7) and in normal control subjects (n = 90). Pulmonary artery pressures were also measured in patients with HF. The eNO and PAP were determined sequentially during therapy with intravenous vasodilators in patients with decompensated HF (n = 7) and in an additional group of patients with HF (n = 13) before and during administration of milrinone. RESULTS The eNO was higher in patients with HF than in control subjects (9.9 +/- 1.1 ppb vs. 6.2 +/- 0.4 ppb, p = 0.002) and inversely correlated with PAP (r = -0.81, p < 0.00001). In marked contrast, patients with decompensated HF exhibited even higher levels of eNO (20.4 +/- 6.2 ppb) and PAP, but there was a loss of the inverse relationship between these two variables. During therapy (7.3 +/- 6 days) with sodium nitroprusside and diuresis, hemodynamics improved, eNO concentrations fell (11.2 +/- 1.2 ppb vs. before treatment, p < 0.05), and the relationship between eNO and PAP was restored. After milrinone, eNO rose proportionally with decreased PAP (p < 0.05). CONCLUSIONS Elevated eNO may reflect a compensatory circulatory mechanism in HF that is lost in patients with clinically decompensated HF. The eNO may be an easily obtainable and quantifiable measure of the response to therapy in advanced HF.

Immunomodulatory effects of systemic low-dose recombinant interleukin-2 and lymphokine-activated killer cells in humans.

SummaryThe adoptive immunotherapy of human cancer using lymphokine-activated killer (LAK) cells in combination with high-dose systemic recombinant interleukin-2 (rIL-2) has been associated with global changes in several hematological and immunological parameters while imposing profound toxicity on patients. We have evaluated an alternative LAK cell therapy utilizing low-dose systemic rIL-2 in 27 consecutive patients with metastatic cancer. We report that the administration of systemic low-dose rIL-2 is also characterized by significant changes in immunological and hematological parameters, which are qualitatively similar to those induced by high-dose rIL-2. Low-dose systemic rIL-2, given by i.v. bolus, is cleared to baseline levels within 240 min of administration. The induction of lymphocytosis and eosinophilia, which has characterized other protocols, is also a feature of this protocol. In addition, low-dose systemic rIL-2/LAK cell immunotherapy results in increased peripheral blood mononuclear cell (PBMC) expression of T-cell activation markers such as OKIa, OKT10 and IL-2 receptor. PBMC sampled approximately 100 h after the final infusion of LAK cells demonstrated a statistically significant increase in their ability to kill natural killer (NK)-sensitive and NK-resistent cell lines such as K562 and Daudi compared to baseline values (P <.05). These data suggest that rIL-2-based immunotherapy using low-dose rIL-2 is capable of inducing quantitative hematological and immunological changes while (in combination with LAK cells) retaining the ability to mediate tumor regressionin vivo.

Implementation of a Hospital-wide Protocol for Induced Hypothermia Following Successfully Resuscitated Cardiac Arrest.

Permanent neurologic impairment following cardiac arrest is often severely debilitating, even after successful resuscitation. Therapeutic hypothermia decreases anoxic brain injury and subsequent cognitive deficits. Current practice guidelines recommend therapeutic hypothermia in comatose survivors of cardiac arrest. To address the multifacets of therapeutic hypothermia, we assembled a multidisciplinary task force including members from various specialties to create an evidence-based guideline with transparency across disciplines and consistency of care. We describe our institutional guidelines for the initiation and management of induced hypothermia in patients successfully resuscitated from a cardiac arrest.

The biological effects of immunosuppression on cellular immunotherapy

Cytoreductive chemotherapy and immunosuppression have been postulated as possible adjuncts to cancer immunotherapy in studies using murine tumour-infiltrating lymphocytes (TIL). Treatment of animals with cyclophosphamide (Cy) therapy alone caused two distinct biological activities that altered the relationship between host and tumour. These two in vivo activities were distinguished by altering the timing and dose of Cy administration relative to tumour implantation. Cy administered 3 days following tumour injection caused a significant decline in the number of pulmonary micrometastases and greater survival compared to untreated controls in proportion to the dose of Cy administered. Further reduction in pulmonary disease was observed when Cy-treated mice were given TIL therapy. The possible role(s) of Cy-induced immunosuppression was studied by injecting Cy 24 h prior to tumour injection. This treatment failed to cause the cytoreductive effect observed when Cy was administered 3 days after tumour since Cy-administration prior to tumour resulted in a significantly higher number of pulmonary metastases and diminished survival compared to untreated controls. Despite the increased number of pulmonary metastases and decreased survival in mice treated with Cy before administration of tumour, therapy with TIL significantly diminished pulmonary disease compared to animals treated with Cy alone. Immunosuppression (without concomitant cytoreductive therapy) prior to TIL treatment significantly prolonged survival. Additional studies with TIL therapy indicate that the survival of animals immunosuppressed prior to tumour injection was significantly longer than controls which received immunotherapy alone. These results suggest that the combustion of immunosuppression plus cellular immunotherapy, which leads to significant survival advantage in these murine tumour models, may possibly augment the clinical response in human TIL trials.

Evaluation of a local ICU sedation guideline on goal-directed administration of sedatives and analgesics

Purpose: Sedatives and analgesics are commonly used in mechanically ventilated patients in the intensive care unit. Sedation guidelines have been shown to improve sedation management as well as various patient outcomes. The main objective was to evaluate adherence to a sedation guideline with both sedative prescribing and documentation of Richmond Agitation-Sedation Scale (RASS) scores. Methods: In a retrospective chart review, data was collected on 111 medical intensive care unit patients mechanically ventilated via endotracheal tube for 12 hours or greater at Brigham and Women’s Hospital. Fifty-seven patients were evaluated pre-guideline implementation and 54 patients were evaluated post-guideline. Results: Significant increases were seen in the post-guideline group in goal-directed sedation with a patient-specific RASS goal in the sedation order: 21.3 vs 85.4% (P < 0.001), and mean number of sedation assessments per 24 hours using the RASS: 4.7 vs 11.4 (P < 0.001). Similarly, this group experienced a higher percentage of RASS scores at their sedation goal: 31.4 vs 44.1% (P < 0.001). No difference was seen in other clinical endpoints. Conclusion: Implementation and routine application of a hospital pain and sedation guideline was associated with significantly improved sedation metrics, such as goal-directed sedation, as well as frequency of sedation level assessment and documentation. An increase was observed in the time that post-guideline patients spent at or near their RASS goal.