Using cluster analysis of cytokines to identify patterns of inflammation in hospitalized patients with community-acquired pneumonia: a pilot study

INTRODUCTION

Patients with severe community-acquired pneumonia (CAP) are believed to have an exaggerated inflammatory response to bacterial infection. Therapies aiming to modulate the inflammatory response have been largely unsuccessful, perhaps reflecting that CAP is a heterogeneous disorder that cannot be modulated by a single anti-inflammatory approach. We hypothesize that the host inflammatory response to pneumonia may be characterized by distinct cytokine patterns, which can be harnessed for personalized therapies.

METHODS

Here, we use hierarchical cluster analysis of cytokines to examine if patterns of inflammatory response in 13 hospitalized patients with CAP can be defined. This was a secondary data analysis of the Community-Acquired Pneumonia Inflammatory Study Group (CAPISG) database. The following cytokines were measured in plasma and sputum on the day of admission: interleukin (IL)-1β, IL-1 receptor antagonist (IL-1ra), IL-6, CXCL8 (IL-8), IL-10, IL-12p40, IL-17, interferon (IFN)γ, tumor necrosis factor (TNF)α, and CXCL10 (IP-10). Hierarchical agglomerative clustering algorithms were used to evaluate clusters of patients within plasma and sputum cytokine determinations.

RESULTS

A total of thirteen patients were included in this pilot study. Cluster analysis identified distinct inflammatory response patterns of cytokines in the plasma, sputum, and the ratio of plasma to sputum.

CONCLUSIONS

Inflammatory response patterns in plasma and sputum can be identified in hospitalized patients with CAP. Characterization of the local and systemic inflammatory response may help to better discriminate patients for enrollment into clinical trials of immunomodulatory therapies.

Prognosis of cirrhotic patients admitted to intensive care unit: a meta-analysis

Background

The best predictors of short- and medium-term mortality of cirrhotic patients receiving intensive care support are unknown.

Methods

We conducted meta-analyses from 13 studies (2523 cirrhotics) after selection of original articles and response to a standardized questionnaire by the corresponding authors. End-points were in-ICU, in-hospital, and 6-month mortality in ICU survivors. A total of 301 pooled analyses, including 95 analyses restricted to 6-month mortality among ICU survivors, were conducted considering 249 variables (including reason for admission, organ replacement therapy, and composite prognostic scores).

Results

In-ICU, in-hospital, and 6-month mortality was 42.7, 54.1, and 75.1%, respectively. Forty-eight patients (3.8%) underwent liver transplantation during follow-up. In-ICU mortality was lower in patients admitted for variceal bleeding (OR 0.46; 95% CI 0.36–0.59; p < 0.001) and higher in patients with SOFA > 19 at baseline (OR 8.54; 95% CI 2.09–34.91; p < 0.001; PPV = 0.93). High SOFA no longer predicted mortality at 6 months in ICU survivors. Twelve variables related to infection were predictors of in-ICU mortality, including SIRS (OR 2.44; 95% CI 1.64–3.65; p < 0.001; PPV = 0.57), pneumonia (OR 2.18; 95% CI 1.47–3.22; p < 0.001; PPV = 0.69), sepsis-associated refractory oliguria (OR 10.61; 95% CI 4.07–27.63; p < 0.001; PPV = 0.76), and fungal infection (OR 4.38; 95% CI 1.11–17.24; p < 0.001; PPV = 0.85). Among therapeutics, only dopamine (OR 5.57; 95% CI 3.02–10.27; p < 0.001; PPV = 0.68), dobutamine (OR 8.92; 95% CI 3.32–23.96; p < 0.001; PPV = 0.86), epinephrine (OR 5.03; 95% CI 2.68–9.42; p < 0.001; PPV = 0.77), and MARS (OR 2.07; 95% CI 1.22–3.53; p = 0.007; PPV = 0.58) were associated with in-ICU mortality without heterogeneity. In ICU survivors, eight markers of liver and renal failure predicted 6-month mortality, including Child–Pugh stage C (OR 2.43; 95% CI 1.44–4.10; p < 0.001; PPV = 0.57), baseline MELD > 26 (OR 3.97; 95% CI 1.92–8.22; p < 0.0001; PPV = 0.75), and hepatorenal syndrome (OR 4.67; 95% CI 1.24–17.64; p = 0.022; PPV = 0.88).

Conclusions

Prognosis of cirrhotic patients admitted to ICU is poor since only a minority undergo liver transplant. The prognostic performance of general ICU scores decreases over time, unlike the Child–Pugh and MELD scores, even recorded in the context of organ failure. Infection-related parameters had a short-term impact, whereas liver and renal failure had a sustained impact on mortality.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-017-0249-6) contains supplementary material, which is available to authorized users.

Using cluster analysis of cytokines to identify patterns of inflammation in hospitalized patients with community-acquired pneumonia: a pilot study

INTRODUCTION

Patients with severe community-acquired pneumonia (CAP) are believed to have an exaggerated inflammatory response to bacterial infection. Therapies aiming to modulate the inflammatory response have been largely unsuccessful, perhaps reflecting that CAP is a heterogeneous disorder that cannot be modulated by a single anti-inflammatory approach. We hypothesize that the host inflammatory response to pneumonia may be characterized by distinct cytokine patterns, which can be harnessed for personalized therapies.

METHODS

Here, we use hierarchical cluster analysis of cytokines to examine if patterns of inflammatory response in 13 hospitalized patients with CAP can be defined. This was a secondary data analysis of the Community-Acquired Pneumonia Inflammatory Study Group (CAPISG) database. The following cytokines were measured in plasma and sputum on the day of admission: interleukin (IL)-1β, IL-1 receptor antagonist (IL-1ra), IL-6, CXCL8 (IL-8), IL-10, IL-12p40, IL-17, interferon (IFN)γ, tumor necrosis factor (TNF)α, and CXCL10 (IP-10). Hierarchical agglomerative clustering algorithms were used to evaluate clusters of patients within plasma and sputum cytokine determinations.

RESULTS

A total of thirteen patients were included in this pilot study. Cluster analysis identified distinct inflammatory response patterns of cytokines in the plasma, sputum, and the ratio of plasma to sputum.

CONCLUSIONS

Inflammatory response patterns in plasma and sputum can be identified in hospitalized patients with CAP. Characterization of the local and systemic inflammatory response may help to better discriminate patients for enrollment into clinical trials of immunomodulatory therapies.

Open and closed models of intensive care unit have different influences on infectious complications in a tertiary care center: A retrospective data analysis

Infectious complications in the intensive care unit (ICU) are associated with higher morbidity, mortality, and increased health care use. Here, we report the results of implementing 2 different models (open vs closed) on infectious complications in the ICU. The closed ICU model was associated with 52% reduction in ventilator-associated pneumonia rate (P = .038) and 25% reduction in central line-associated bloodstream infection rate (P = .631). We speculate that a closed ICU model allows clinical leadership centralization that further facilitates standardized care delivery that translates into fewer infectious complications.

Effect of Sleep State and Position on Obstructive Respiratory Events Distribution in Adolescent Children

STUDY OBJECTIVES

This study aimed to examine the effect of sleep state (rapid eye movement [REM] versus non-rapid eye movement [NREM]) and position (supine versus non-supine position) on obstructive respiratory events distribution in adolescent population (ages 12 to 18 y).

METHODS

This was a retrospective study that included 150 subjects between the ages of 12 to 18 y with an apnea-hypopnea index (AHI) > 1/h. Subjects using REM sleep-suppressant medications and subjects with history of genetic anomalies or craniofacial syndromes were excluded.

RESULTS

The median age was 14 y with interquartile range (IQR) of 13 to 16 y, 56% of patients were males and the median body mass index (BMI) z-score was 2.35 (IQR: 1.71-2.59) with 77.3% of patients fulfilling obesity criteria. Respiratory obstructive events were more common in REM sleep. The median REM obstructive AHI (OAHI) was 8.9 events per hour (IQR: 2.74-22.8), whereas the median NREM OAHI was 3.2 events per hour (IQR: 1.44-8.29; p < 0.001). African American adolescents had more REM obstructive events with median REM OAHI of 13.2 events per hour (IQR: 4.88-30.6), which was significantly higher than median REM OAHI of 4.94 (IQR: 2.05-11.36; p = 0.004) in white adolescents. Obstructive events were more common in supine position with higher median supine OAHI of 6.55 (IQR: 4-17.73) when compared to median non-supine OAHI of 2.94 (IQR: 1-6.54; p < 0.001).

CONCLUSIONS

This study shows that sleep related obstructive respiratory events in the adolescents (12 to 18 y of age) occur predominantly in REM sleep and in supine position.

The upper respiratory tract microbiome of hospitalised patients with community-acquired pneumonia of unknown aetiology: a pilot study

The composition of the upper respiratory tract microbiome may play an important role in the development of lower respiratory tract infections. Here, we characterised the microbiome of the nasopharynx and oropharynx of hospitalised patients with community-acquired pneumonia (CAP) with unknown aetiology in an attempt to obtain insight into the aetiology of CAP. A random sample of 10 patients hospitalised with CAP previously enrolled in a separate clinical trial (ClinicalTrials.gov registry, Study ID: NCT01248715) in which a complete microbiological workup was not able to define an aetiology were analysed in this pilot study. This larger trial (n = 1,221) enrolled patients from 9 adult hospitals in Louisville, Kentucky, USA. Nasopharyngeal and oropharyngeal swabs were obtained for metagenomic analysis. Polymerase chain reaction (PCR) for Streptococcus pneumoniae was performed in all patients. One patient had a distinct nasophararyngeal microbiome consisting largely of Haemophilus influenzae. This was the only patient with a negative PCR for S. pneumoniae in both nasophararyngeal and oropharyngeal specimens. Overall, substantial differences were found between nasophararyngeal and oropharyngeal microbiomes. The upper respiratory tract microbiome of only one patient suggested H. influenzae as a probable aetiology of CAP. Although this was a pilot study of only 10 patients, the presence of S. pneumoniae in the upper respiratory tract of the other 9 patients warrants further investigation.

Extended Anticoagulant and Aspirin Treatment for the Secondary Prevention of Thromboembolic Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Patients who have had an unprovoked deep venous thrombosis (DVT) or pulmonary embolus (PE) are at a high risk for recurrent venous thromboembolism (VTE). Extended "life-long" anticoagulation has been recommended in these patients. However, the risk benefit ratio of this approach is controversial and the role of the direct oral anticoagulants (DOACs) and aspirin is unclear. Furthermore, in some patients with a "weak provoking factor" there is clinical equipoise regarding continuation or cessation of anticoagulant therapy after treatment of the acute VTE event.

OBJECTIVE

A systematic review and meta-analysis to determine the risks (major bleeding) and benefits (recurrent VTE and mortality) of extended anticoagulation with vitamin k antagonists (VKA), DOACs and aspirin in patients with an unprovoked VTE and in those patients with clinical equipoise regarding continuation or cessation of anticoagulant therapy. In addition, we sought to determine the risk of recurrent VTE events once extended anti-thrombotic therapy was discontinued.

DATA SOURCES

MEDLINE, Cochrane Register of Controlled Trials, citation review of relevant primary and review articles.

STUDY SELECTION

Randomized placebo-controlled trials (RCTs) that compared the risk of recurrent VTE in patients with an unprovoked DVT or PE who had been treated for at least 3 months with a VKA or a DOAC and were then randomized to receive an oral anti-thrombotic agent or placebo for at least 6 additional months. We included studies that included patients in whom clinical equipoise existed regarding the continuation or cessation of anticoagulant therapy.

DATA EXTRACTION

Independent extraction of articles by both authors using predefined data fields, including study quality indicators. Data were abstracted on study size, study setting, initial event (DVT or PE), percentage of patients where the initial VTE event was unprovoked, the number of recurrent VTE events, major bleeds and mortality during the period of extended anticoagulation in the active treatment and placebo arms. In addition, we recorded the event rate once extended treatment was stopped. Meta-analytic techniques were used to summarize the data. Studies were grouped according to the type of anti-thrombotic agent.

DATA SYNTHESIS

Seven studies which enrolled 6778 patients met our inclusion criteria; two studies evaluated the extended use of Coumadin, three studies evaluated a DOAC and two studies evaluated the use of aspirin. The duration of followup varied from 6 to 37 months. In the Coumadin and aspirin studies 100% of the randomized patients had an unprovoked VTE, while in the DOAC studies between 73.5% and 93.2% of the VTE events were unprovoked. In the control group recurrent VTE occurred in 9.7% of patients compared to 2.8% in the active treatment group (OR 0.21; 95% CI 0.11-0.42, p<0.0001). VKA, DOACs and aspirin significantly reduced the risk of recurrent VTE, with VKA and DOACs being significantly more effective than aspirin. Major bleeding events occurred in 12 patients in the control group (0.4%) and 25 of 3815 (0.6%) patients in the active treatment group (OR 1.64; 95% CI 0.69-3.90, NS). There were 39 (1.3%) deaths in control patients and 33 (0.9%) deaths in the anti-thrombotic group during the treatment period (OR 0.73; 95% CI 0.40-1.33, NS). Patients whose initial VTE event was a PE were more likely to have a recurrent PE than a DVT. The annualized event rate after discontinuation of extended antithrombotic therapy was 4.4% in the control group and 6.5% in the active treatment arm.

CONCLUSIONS

VKA, DOACs and aspirin significantly reduced the risk of recurrent VTE, with DOACs and VKA being more effective than aspirin. The decision regarding life-long anticoagulation following an unprovoked DVT or PE should depend on the patients' risk for recurrent PE as well as the patients' values and preferences.

Bacteremic pneumococcal pneumonia: clinical outcomes and preliminary results of inflammatory response

PURPOSE

Further examination of clinical outcomes and inflammatory response of bacteremic pneumococcal community-acquired pneumonia (CAP) is of great interest to enhance the care of patients with pneumococcal CAP.

METHODS

This is a secondary analysis of the Community Acquired Pneumonia Organization (CAPO) to compare the time to clinical stability (TCS), length of hospital stay (LOS), and in-hospital mortality of hospitalized pneumococcal CAP patients with and without bacteremia. To measure the effect of bacteremia in pneumococcal CAP patients on outcomes, we modeled all-cause in-hospital mortality using a Poisson regression model, and TCS and LOS using Cox proportional hazards models. Adjusted multivariate regression models were also used to predict the probability of occurrence of each of the study outcomes. To investigate the inflammatory response, we measured the plasma levels of pro- and anti-inflammatory cytokines [tumor necrosis factor (TNF)-α, interleukin (IL)-1rα, IL-6, IL-8, IL-10], inflammatory biomarkers [C-reactive protein (CRP), pro-calcitonin (PCT), and B-type natriuretic peptide (BNP)], and peripheral blood neutrophil responses in 10 patients, 4 bacteremic and 6 non-bacteremic pneumococcal CAP, upon admission and every other day during the first 6 days of hospitalization. Functional data were presented as median and standard error of the median (SEM); due to small number of samples no statistical comparisons were performed between groups.

RESULTS

From 833 pneumococcal CAP patients, 394 patients (47 %) were bacteremic. Bacteremic pneumococcal CAP were less likely to reach TCS with an adjusted hazard ratio (AHR) of 0.82 (95 % CI 0.69-0.97; p = 0.02) and had higher in-hospital mortality with an AHR of 1.63 (95 % CI 1.06-2.50, p = 0.026). Bacteremic pneumococcal CAP patients had a longer LOS than non-bacteremic pneumococcal CAP (p < 0.003). Higher plasma levels of CRP, PCT, and BNP were found in bacteremic than in non-bacteremic patients. The bacteremic group had consistently higher plasma levels of both pro- and anti-inflammatory cytokines. The blood neutrophil functional responses were similar in both groups of patients.

CONCLUSIONS

Bacteremic pneumococcal CAP patients were significantly associated with higher in-hospital mortality, lower TCS, and longer LOS. HIV-infected patients showed a greater mortality which was not statistically significant. Bacteremic pneumococcal CAP patients had higher levels of biomarkers and systemic cytokines.

Midregional proadrenomedullin for prognosis in community-acquired pneumonia: a systematic review

INTRODUCTION

The initial prognostic assessment of patients with community-acquired pneumonia( CAP) has important clinical implications. We hypothesized that midregional proadrenomedullin(MR-proADM) is a valuable test for the prediction of outcomes in patients with CAP.Methods: We performed a systemic review of the literature and a meta-analysis to evaluate the prognostic value of MR-proADM for short and long-term mortality in patients with CAP.Results: Twelve studies were included in the systematic review. Elevated MR-proADM was associated with an increase in short-term mortality (OR Z 6.8; 95% CI: 4.65-10.13; P value < 0.001) and complications (OR = 5.0; 95% CI: 3.86-6.49; P value < 0.001). The pooled analysis of 4 studies showed an improvement in the discriminant ability by 8% (95% CI: 2%e14%)when MR-proADM was added to CURB-65/CRB-65. Studies that reported long-term prognosis indicated an increased risk of death in patients with elevated MR-proADM.Conclusion: Elevated level of MR-proADM is significantly associated with both short-term mortality and complications in patients with CAP. Studies also indicate that MR-proADM has prognostic value for prediction of long-term mortality in these patients. The addition of MR-proADM improves the discriminant ability of CURB-65/CRB-65.

Predictive Role of Admission Lactate Level in Critically Ill Patients with Acute Upper Gastrointestinal Bleeding

BACKGROUND

The predictive role of lactate in critically ill patients with acute upper gastrointestinal bleeding (UGIB) remains to be elucidated.

OBJECTIVE

The primary objective of this study was to assess the value of lactate level on admission to predict in-hospital death in patients with UGIB admitted to the intensive care unit (ICU). The secondary objective was to assess whether lactate level adds predictive value to the clinical Rockall score in these patients.

METHODS

This was a retrospective cohort study that included 133 patients with acute UGIB admitted to the ICU. Inclusion criteria were age > 18 years and presence of UGIB on admission to the ICU.

RESULTS

Mean age was 55.4 years old and 64.7% were male. The most common cause of gastrointestinal bleeding was peptic ulcer disease, followed by erosive esophagitis/gastritis. The in-hospital mortality was 22.6%. Median lactate level in survivors and nonsurvivors was 2.0 (interquartile range [IQR] 1.2-4.2 mmol/L) and 8.8 (IQR 3.4-13.3 mmol/L; p < 0.01), respectively. The receiver operating characteristic (ROC) area to predict in-hospital death for clinical Rockall score and lactate level (0.82) was significantly higher than the ROC area for the clinical Rockall score alone (0.69) (p < 0.01).

CONCLUSIONS

In patients admitted to the ICU with acute UGIB, lactate level on admission has a high sensitivity but low specificity for predicting in-hospital death. Lactate level adds to the predictive value of the clinical Rockall score. Given its high sensitivity, lactate level can be used in addition to other prediction tools to predict outcomes in patients with UGIB.

Contrasting inflammatory responses in severe and non-severe community-acquired pneumonia

The objective of this study was to compare systemic and local cytokine profiles and neutrophil responses in patients with severe versus non-severe community-acquired pneumonia (CAP). Hospitalized patients with CAP were grouped according to the pneumonia severity index (PSI), as non-severe (PSI < 91 points) or severe (PSI ≥ 91 points). Blood and sputum samples were collected upon admission. Compared to non-severe CAP patients, the severe CAP group showed higher plasma levels of pro- and anti-inflammatory cytokines but in contrast, lower sputum concentrations of pro-inflammatory cytokines. Blood neutrophil functional responses were elevated in CAP patients compared to healthy controls. However, neutrophils from severe CAP patients showed reduced respiratory burst activity compared to the non-severe group. Results indicate that patients with severe CAP fail to mount a robust local pro-inflammatory response but exhibit instead a more substantial systemic inflammatory response, suggesting that a key driver of CAP severity may be the ability of the patient to generate an optimal local inflammatory response.