The systemic mediator-associated response test identifies patients in failed sepsis clinical trials among whom novel drugs reduce mortality

Stop-It Randomized Clinical Trial (RCT) for Intra-Abdominal Infection (IAI) Revisited: Multivariate Analyses To Identify Treatment Effects 4 Days Antibiotic Agents Versus Resolution Signs/Symptoms + 2 Days and Drivers of Outcomes

Background: The STOP-IT randomized clinical trial (RCT) pioneered limiting antibiotic agents in intra-abdominal infection (IAI) with adequate surgical source control, but NIH funding ended before an adequate power sample size was enrolled to determine equivalence between STOP-IT study regimens: four days of antibiotic agents (4-days) after source control versus antibiotic agents until resolution of signs and symptoms of IAI plus two days (standard of care [SOC]). The objective of this investigation was to identify possible significant treatment effects 4-days versus SOC, and independent variables defining and predicting outcomes. Methods: De-identified data from 518 STOP-IT subjects were analyzed retrospectively in two groups: 4-days (n = 258) and SOC (n = 260), and separately as one group (n = 518). Statistics: multivariate regression analysis, chi-squared, and simple Cohen kappa coefficient. Results: No pre-randomization variable predicted protocol FAILURE (surgical site infection, recurrent IAI, or death at 30 d) in 4-day subjects. APACHE II predicted SOC FAILURE, but no cut point determined treatment effect (AUC = 0.608). Both observations implied that FAILURE may not reflect patient outcomes. Additionally, Cohen kappa for FAILURE and hospitalization at 7, 14, and 21 days was weak (0.1154, 0.2084, and 0.1969, respectively) with high numbers of discordant values. Pre-randomization variables associated with hospitalization/discharge at days 7, 14, and 21: extra-abdominal infection 1 (p < 0.0001), APACHE II score (p < 0.0001), age (p = 0.006), and WBC maximum (p < 0.05). However, all of these pre-randomization variables did not predict FAILURE, except APACHE II. Conclusions: Poor Cohen kappa coefficients indicate STOP-IT FAILURE agreed only weakly with hospital/discharge at 7, 14, or 21 days, and is not a valid reliable endpoint in IAI or for determining success or failure of any treatment. Pre-randomization extra-abdominal infection, APACHE II score, age, and WBC maximum strongly predicted hospitalization, but only APACHE II predicted failure. The study should use the appropriate sample size calculation when doing an equivalence on the basis of the Two One-Sided Test design. RCTs in IAI need prospectively validated clinically reliable endpoints that align with known patient outcomes that determine success.

Prospectively validated preoperative prediction of weight and co-morbidity resolution in individual patients comparing five bariatric operations

BACKGROUND

No method preoperatively predicts the postoperative bariatric surgery outcomes in individual patients. Decisions for or against surgery and operation choice remain subjective. Only 1% of qualifying patients embrace bariatric surgery.

OBJECTIVE

To predict preoperatively and validate prospectively the weight and co-morbidity resolution in individual patients after open Roux-en-Y gastric bypass (RYGB) and laparoscopic Roux-en-Y gastric bypass (LRYGB), laparoscopic adjustable gastric band (LAGB), sleeve gastrectomy (SG), and biliopancreatic diversion/duodenal switch (BPD/DS).

SETTING

Surgical Review Corporation BOLD database, 2007-2010.

METHODS

A total of 166,601 patients who had undergone RYGB (n = 5389), LRYGB (n = 83,059), LAGB (n = 67,514), SG (n = 8966), or BPD/DS (n = 1673) were randomized into modeling (n = 124,053) and validation (n = 42,548) groups. From preoperative data, multivariate linear and logistic regression predicted weight and co-morbidities at 2, 6, 12, 18, and 24 months postoperatively. Model fit was examined by R² and receiver operating characteristic/area under the curve and predicted versus observed results via Pearson correlation coefficient and sensitivity/specificity.

RESULTS

Follow-up at 2/24 months was 120,909/11,014 for the modeling group and 41,528/3703 for validation. Weight models' R² was .910, .813, .725, .638, and .613 at 2, 6, 12, 18, and 24 months, respectively. The categorical receiver operating characteristic/area under the curve was .617 to .949 for 24-month predictions. Pearson continuous coefficients were .969 and .811 at 2 and 24 months, respectively. The median 24-month sensitivity and specificity of co-morbidity resolution were 79.2% and 97.42%, respectively.

CONCLUSIONS

Prospectively validated preoperative models predict, in individual patients, weight and obesity co-morbidities 2 years in advance for RYGB, LRYGB, LAGB, SG, and BPD/DS. This advance knowledge facilitates choosing the operation that is best for each individual and may encourage more patients to choose bariatric surgery.

The leukocyte-stiffening property of plasma in early acute respiratory distress syndrome (ARDS) revealed by a microfluidic single-cell study: the role of cytokines and protection with antibodies

Background

Leukocyte-mediated pulmonary inflammation is a key pathophysiological mechanism involved in acute respiratory distress syndrome (ARDS). Massive sequestration of leukocytes in the pulmonary microvasculature is a major triggering event of the syndrome. We therefore investigated the potential role of leukocyte stiffness and adhesiveness in the sequestration of leukocytes in microvessels. 

Methods

This study was based on in vitro microfluidic assays using patient sera. Cell stiffness was assessed by measuring the entry time (ET) of a single cell into a microchannel with a 6 × 9–μm cross-section under a constant pressure drop (ΔP = 160 Pa). Primary neutrophils and monocytes, as well as the monocytic THP-1 cell line, were used. Cellular adhesiveness to human umbilical vein endothelial cells was examined using the laminar flow chamber method. We compared the properties of cells incubated with the sera of healthy volunteers (n = 5), patients presenting with acute cardiogenic pulmonary edema (ACPE; n = 6), and patients with ARDS (n = 22), of whom 13 were classified as having moderate to severe disease and the remaining 9 as having mild disease. 

Results

Rapid and strong stiffening of primary neutrophils and monocytes was induced within 30 minutes (mean ET >50 seconds) by sera from the ARDS group compared with both the healthy subjects and the ACPE groups (mean ET <1 second) (p < 0.05). Systematic measurements with the THP-1 cell line allowed for the establishment of a strong correlation between stiffening and the severity of respiratory status (mean ET 0.82 ± 0.08 seconds for healthy subjects, 1.6 ± 1.0 seconds for ACPE groups, 10.5 ± 6.1 seconds for mild ARDS, and 20.0 ± 8.1 seconds for moderate to severe ARDS; p < 0.05). Stiffening correlated with the cytokines interleukin IL-1β, IL-8, tumor necrosis factor TNF-α, and IL-10 but not with interferon-γ, transforming growth factor-β, IL-6, or IL-17. Strong stiffening was induced by IL-1β, IL-8, and TNF-α but not by IL-10, and incubations with sera and blocking antibodies against IL-1β, IL-8, or TNF-α significantly diminished the stiffening effect of serum. In contrast, the measurements of integrin expression (CD11b, CD11a, CD18, CD49d) and leukocyte–endothelium adhesion showed a weak and slow response after incubation with the sera of patients with ARDS (several hours), suggesting a lesser role of leukocyte adhesiveness compared with leukocyte stiffness in early ARDS. 

Conclusions

The leukocyte stiffening induced by cytokines in the sera of patients might play a role in the sequestration of leukocytes in the lung capillary beds during early ARDS. The inhibition of leukocyte stiffening with blocking antibodies might inspire future therapeutic strategies.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-1157-5) contains supplementary material, which is available to authorized users.

Sepsis chronically in MARS: systemic cytokine responses are always mixed regardless of the outcome, magnitude, or phase of sepsis

The paradigm of systemic inflammatory response syndrome-to-compensatory anti-inflammatory response syndrome transition implies that hyperinflammation triggers acute sepsis mortality, whereas hypoinflammation (release of anti-inflammatory cytokines) in late sepsis induces chronic deaths. However, the exact humoral inflammatory mechanisms attributable to sepsis outcomes remain elusive. In the first part of this study, we characterized the systemic dynamics of the chronic inflammation in dying (DIE) and surviving (SUR) mice suffering from cecal ligation and puncture sepsis (days 6-28). In the second part, we combined the current chronic and previous acute/chronic sepsis data to compare the outcome-dependent inflammatory signatures between these two phases. A composite cytokine score (CCS) was calculated to compare global inflammatory responses. Mice were never sacrificed but were sampled daily (20 μl) for blood. In the first part of the study, parameters from chronic DIE mice were clustered into the 72, 48, and 24 h before death time points and compared with SUR of the same post-cecal ligation and puncture day. Cytokine increases were mixed and never preceded chronic deaths earlier than 48 h (3- to 180-fold increase). CCS demonstrated simultaneous and similar upregulation of proinflammatory and anti-inflammatory compartments at 24 h before chronic death (DIE 80- and 50-fold higher versus SUR). In the second part of the study, cytokine ratios across sepsis phases/outcomes indicated steady proinflammatory versus anti-inflammatory balance. CCS showed the inflammatory response in chronic DIE was 5-fold lower than acute DIE mice, but identical to acute SUR. The systemic mixed anti-inflammatory response syndrome-like pattern (concurrent release of proinflammatory and anti-inflammatory cytokines) occurs irrespective of the sepsis phase, response magnitude, and/or outcome. Although different in magnitude, neither acute nor chronic septic mortality is associated with a predominating proinflammatory and/or anti-inflammatory signature in the blood.