Improved Early Detection of Sepsis in the ED With a Novel Monocyte Distribution Width Biomarker

Reviewing the value of leukocytes cell population data (CPD) in the management of sepsis

Sepsis is a medical emergency that describes the body's systemic immune response to an infection and can lead to end-stage organic dysfunction and death. Despite the advances in understanding the pathophysiology of this syndrome and therapies, sepsis remains one of the leading causes of morbidity and mortality in critically ill patients. Early diagnosis and rapid intervention are essential to improve outcomes, which inspired the concept "golden hour," during which the correction of shock and organic dysfunction can improve the patients' outcomes. But the initial presentation of sepsis is often nonspecific and its severity is difficult to assess. Anomalies in temperature, heart and respiratory rates and leukocyte counts are manifestations of systemic inflammatory response syndrome (SIRS). Diagnosis, management and follow-up of patients with sepsis remains a challenge, and diverse biomarkers have been proposed for the timely diagnosis and prognosis of septic patients: lactic acid, procalcitonin (PCT), C-reactive protein, immature granulocytes. The host's initial response to infection is a humoral, cellular and neuroendocrine reaction to infection, and leukocytes interact with endothelial cells. The new generation of hematological analyzers incorporates technological innovations allowing to expand the information derived from the complete blood count: new leukocyte derived parameters are emerging as potentially useful markers in different clinical situations. Additional research parameters cell population data (CPD), characterizing different leukocyte populations have become available, and preliminary observations suggest their utility in the diagnosis of sepsis. This review emphasizes the value of CPD, reported by modern cellular counters for early recognition of sepsis, and therefore the potential improvement in patient outcomes.

Reference interval of monocyte distribution width (MDW) in healthy blood donors

BACKGROUND

The aim of the study was to accurately establish the reference interval (RI) of monocyte distribution width (MDW) in healthy blood donors by the direct method using different statistical approaches.

METHODS

MDW was measured in 486 subjects. RI of MDW was calculated by the non-parametric method, the robust method and, the Harrell-Davis bootstrap method and using different tests to identify potential outliers (Dixon-Reed and Tukey).

RESULTS

Lower and upper reference limits of the RI calculated by the non-parametric method were, 16.22 (90%CI 15.78-16.47) - 23.15 (90%CI 22.80-24.10) (without outlier removal), and 16.44 (90%CI 16.21-16.67) - 22.99 (90%CI 22.33-23.22) (after outlier removal). The RIs based on the robust method were, respectively, 16.29-22.98 (without) and 16.50-22.67 (with outlier removal). Finally, the RIs calculated by the Harrell-Davis bootstrap method, without or after outlier removal, were 16.19-23.24 and 16.43-22.93. Thus, the RIs obtained by the three calculation methods were very similar. Additionally, no RI partition was done since no significant gender or age association was found.

CONCLUSIONS

Our results support the use of a unique RI of MDW, independently of sex and age.

Monocyte distribution width enhances early sepsis detection in the emergency department beyond SIRS and qSOFA

Background

The initial presentation of sepsis in the emergency department (ED) is difficult to distinguish from other acute illnesses based upon similar clinical presentations. A new blood parameter, a measurement of increased monocyte volume distribution width (MDW), may be used in combination with other clinical parameters to improve early sepsis detection. We sought to determine if MDW, when combined with other available clinical parameters at the time of ED presentation, improves the early detection of sepsis.

Methods

A retrospective analysis of prospectively collected clinical data available during the initial ED encounter of 2158 adult patients who were enrolled from emergency departments of three major academic centers, of which 385 fulfilled Sepsis-2 criteria, and 243 fulfilled Sepsis-3 criteria within 12 h of admission. Sepsis probabilities were determined based on MDW values, alone or in combination with components of systemic inflammatory response syndrome (SIRS) or quick sepsis-related organ failure assessment (qSOFA) score obtained during the initial patient presentation (i.e., within 2 h of ED admission).

Results

Abnormal MDW (> 20.0) consistently increased sepsis probability, and normal MDW consistently reduced sepsis probability when used in combination with SIRS criteria (tachycardia, tachypnea, abnormal white blood count, or body temperature) or qSOFA criteria (tachypnea, altered mental status, but not hypotension). Overall, and regardless of other SIRS or qSOFA variables, MDW > 20.0 (vs. MDW ≤ 20.0) at the time of the initial ED encounter was associated with an approximately 6-fold increase in the odds of Sepsis-2, and an approximately 4-fold increase in the odds of Sepsis-3.

Conclusions

MDW improves the early detection of sepsis during the initial ED encounter and is complementary to SIRS and qSOFA parameters that are currently used for this purpose. This study supports the incorporation of MDW with other readily available clinical parameters during the initial ED encounter for the early detection of sepsis.

Trial registration

ClinicalTrials.gov, NCT03145428. First posted May 9, 2017. The first subjects were enrolled June 19, 2017, and the study completion date was January 26, 2018.

Monocyte Distribution Width: A Novel Indicator of Sepsis-2 and Sepsis-3 in High-Risk Emergency Department Patients

Supplemental Digital Content is available in the text.

Objectives:

Most septic patients are initially encountered in the emergency department where sepsis recognition is often delayed, in part due to the lack of effective biomarkers. This study evaluated the diagnostic accuracy of peripheral blood monocyte distribution width alone and in combination with WBC count for early sepsis detection in the emergency department.

Design:

An Institutional Review Board approved, blinded, observational, prospective cohort study conducted between April 2017 and January 2018.

Setting:

Subjects were enrolled from emergency departments at three U.S. academic centers.

Patients:

Adult patients, 18–89 years, with complete blood count performed upon presentation to the emergency department, and who remained hospitalized for at least 12 hours. A total of 2,212 patients were screened, of whom 2,158 subjects were enrolled and categorized per Sepsis-2 criteria, such as controls (n = 1,088), systemic inflammatory response syndrome (n = 441), infection (n = 244), and sepsis (n = 385), and Sepsis-3 criteria, such as control (n = 1,529), infection (n = 386), and sepsis (n = 243).

Interventions:

The primary outcome determined whether an monocyte distribution width of greater than 20.0 U, alone or in combination with WBC, improves early sepsis detection by Sepsis-2 criteria. Secondary endpoints determined monocyte distribution width performance for Sepsis-3 detection.

Measurements and Main Results:

Monocyte distribution width greater than 20.0 U distinguished sepsis from all other conditions based on either Sepsis-2 criteria (area under the curve, 0.79; 95% CI, 0.76–0.82) or Sepsis-3 criteria (area under the curve, 0.73; 95% CI, 0.69–0.76). The negative predictive values for monocyte distribution width less than or equal to 20 U for Sepsis-2 and Sepsis-3 were 93% and 94%, respectively. Monocyte distribution width greater than 20.0 U combined with an abnormal WBC further improved Sepsis-2 detection (area under the curve, 0.85; 95% CI, 0.83–0.88) and as reflected by likelihood ratio and added value analyses. Normal WBC and monocyte distribution width inferred a six-fold lower sepsis probability.

Conclusions:

An monocyte distribution width value of greater than 20.0 U is effective for sepsis detection, based on either Sepsis-2 criteria or Sepsis-3 criteria, during the initial emergency department encounter. In tandem with WBC, monocyte distribution width is further predicted to enhance medical decision making during early sepsis management in the emergency department.

The complete blood count to diagnose septic shock

The complete blood count has a longstanding role in the diagnosis of septic shock. Despite its limitations, this is a pragmatic tool because patients will generally have a blood count measured upon presentation to the hospital. Therefore, it is sensible to extract as much information from these values as possible. Although the white blood cell count continues to attract the most attention, it is the least useful. Emerging evidence suggests that emphasis should be shifted to the neutrophil to lymphocyte ratio (NLR) and perhaps the fraction of immune granulocytes.

Comparison of Monocyte Distribution Width (MDW) and Procalcitonin for early recognition of sepsis

We carried out a prospective observational study to evaluate whether Monocyte Distribution Width (MDW) may play a role in identifying patients with sepsis in comparison with Procalcitonin (PCT). We prospectively enrolled all consecutive patients hospitalized at the Infectious Diseases Unit of Pescara General Hospital for bacterial infection or sepsis. MDW values were collected for all patients. Clinical characteristics, demographic data, past and present medical history, microbiological results, PCT, as well as neutrophil and monocytes indices at entry were compared in the 2 groups. Two-hundred-sixty patients were enrolled, 63.5% males, aged 59.1±19.5 years. Sepsis was diagnosed in 105 (40.4%); in 60 (57.1%) at least 1 microorganism was isolated from blood cultures. In multivariate models, MDW as a continuous variable (OR:1.57 for each unit increase; 95%CI: 1.31–1.87, p<0.001) and PCT˃1 ng/mL (OR: 48.5; 95%CI: 14.7–160.1, p<0.001) were independently associated with sepsis. Statistical best cut points associated with sepsis were 22.0 for MDW and 1.0 ng/mL for PCT whereas MDW values<20 were invariably associated with negative blood cultures. At ROC curve analysis, the AUC of MDW (0.87) was nearly overlapping that of PCT (0.88). Our data suggest that incorporating MDW within current routine WBC counts and indices may be of remarkable use for detection of sepsis. Further research is warranted.

Incorporation of dynamic segmented neutrophil-to-monocyte ratio with leukocyte count for sepsis risk stratification

The association between sepsis and segmented neutrophil-to-monocyte (SeMo) ratio is unclear. We postulated that an increase in dynamic SeMo ratio measurement can be applied in risk stratification. This retrospective study included 727 consecutive sepsis patients in medical intensive care units (ICUs), including a subpopulation of 153 patients. According to the leukocyte (white blood cell, WBC) count on day 3 (normal range, between 4,000/µL and 12,000/µL) and delta SeMo (value of SeMo ratio on day 3 minus value of SeMo ratio on day 1; normal delta SeMo, <7), patients were grouped into 3 (delta SeMo & WBC tool). The survival lines separated significantly with hazard ratios of 1.854 (1.342–2.560) for the delta SeMo or WBC abnormal group and 2.860 (1.849–4.439) for the delta SeMo and WBC abnormal group compared to the delta SeMo and WBC normal group. Delta SeMo & WBC tool and delta sequential organ failure assessment (SOFA) tool performed better than the other tools (delta SeMo, delta WBC, day 3 WBC, and day 1 WBC). Severity in delta SeMo & WBC tool and delta SeMo tool reflected the immune dysfunction score, cytokine expression, and human leukocyte antigen D-related monocyte expression on day 1 and day 3. There was correspondence between delta SOFA and delta WBC and between delta SeMo and delta cytokine expression. Incorporation of dynamic SeMo ratio with WBC count provides risk stratification for sepsis patients admitted in the ICU.

Agomelatine could prevent brain and cerebellum injury against LPS-induced neuroinflammation in rats

Sepsis, systemic hyper-inflammatory immune response, causes the increase of morbidity and mortality rates due to multi-organ diseases such as neurotoxicity. Lipopolysaccharide (LPS) induces inflammation, oxidative stress and apoptosis to cause brain damage. We aimed to evaluate the antioxidant, anti-inflammatory and antiapoptotic effects of Agomelatine (AGM) on LPS induced brain damage via NF-kB signaling. Twenty-four animals were divided into three groups as control, LPS (5 mg/kg) and LPS + AGM (20 mg/kg). Six hours after the all administrations, rats were sacrificed, brain tissues were collected for biochemical, histopathological and immunohistochemical analysis. In LPS group; total oxidant status (TOS), OSI index, Caspase-8 (Cas-8), NF-kß levels increased and Total antioxidant status (TAS) levels decreased biochemically and Cas-8, haptoglobin and IL-10 expressions increased and sirtuin-1 (SIRT-1) levels decreased immunohistochemically. AGM treatment reversed these parameters except haptoglobin levels in hippocampus and SIRT-1 levels in cerebellum. Besides, AGM treatment blocked the phosphorylation of NF-kB biochemically and ameliorated increased the levels of hyperemia, edema and degenerative changes histopathologically. In conclusion, AGM enhanced SIRT-1 levels to negatively regulate the transcription and activation of p-NF-kB/p65 which caused to ameliorate inflammation, oxidative stress and apoptosis.

The Leukocyte VCS Parameters Compared with Procalcitonin, Interleukin-6, and Soluble Hemoglobin Scavenger Receptor sCD163 for Prediction of Sepsis in Patients with Cirrhosis

Background

Patients with liver cirrhosis have a high risk of sepsis and a poor prognosis. Recently, a new standard for sepsis (Sepsis-3) has been proposed in the general population. The Coulter Lh 750 hematology analyzer can evaluate mean volume, conductivity, scatter, and distribution width of leukocyte. We tried to use Sepsis-3 criteria to study the diagnostic value of volume, conductivity, and scattering (VCS) parameters in sepsis and infection in patients with liver cirrhosis compared with traditional infection markers (PCT, IL-6, sCDl63).

Methods

A blinded, cohort study was conducted in three different ED populations within three affiliated hospitals. A total of 249 patients with liver cirrhosis were enrolled in the study. According to the “Sepsis-3” consensus criteria, clinical history, and laboratory examination, the subjects were divided into sepsis (n = 54), patients with infections (n = 95), and patients without systemic infections (n = 100). The blood samples of the patients were collected at the time of ED admission and were evaluated for the detection of sepsis.

Results

The differences of MNV, MNS, MMV, MMS, MLV, NDW, and MDW in the three groups were statistically significant. In the diagnosis of sepsis in patients with liver cirrhosis, the sensitivity of combined detection of MMV and MDW was 88.89%; the specificity was 74%. This sensitivity was significantly better than the 83.3% achieved using 0.97 mg/L as the cutoff for sCD163. In the diagnosis of infection in cirrhosis, the sensitivity of combination of MNV and MMS was increased to 86.32%; the specificity was 92%. The sensitivity was the same as that achieved by using 0.31 ng/mL as the cutoff value of PCT, but the specificity increased.

Conclusion

The leukocyte VCS parameter could be potential parameters for indicating sepsis and infection in patients with liver cirrhosis. The combined detection of MMV and MDW seemed to be helpful for the diagnosis of sepsis in these patients, and the combination of MNV and MMS could better indicate infection for them.

Predicted Economic Benefits of a Novel Biomarker for Earlier Sepsis Identification and Treatment: A Counterfactual Analysis

To estimate the potential clinical and health economic value of earlier sepsis identification in the emergency department using a novel diagnostic marker, monocyte distribution width.

DESIGN

The analysis was conducted in two phases: 1) an analysis of the pivotal registration trial evidence to estimate the potential benefit of monocyte distribution width for early sepsis identification and (2) a cost-consequence analysis to estimate the potential economic and clinical benefits that could have resulted from earlier administration of antibiotics for those patients.

SETTING

Sepsis identified in the emergency department which led to inpatient hospitalizations.

PATIENTS

Adult sepsis patients admitted through the emergency department.

INTERVENTIONS

None. This was a model simulation of clinical and economic outcomes of monocyte distribution width based on results from a noninterventional, multicenter clinical trial.

MEASUREMENTS AND MAIN RESULTS

Among the 385 patients with sepsis, a total of 349 were eligible for inclusion. Sixty-seven percent of patients were predicted to benefit from monocyte distribution width results, resulting in an estimated mean reduction in time to antibiotics administration from 3.98 hours using standard of care to 2.07 hours using monocyte distribution width + standard of care. Based on this simulated reduction in time to antibiotics, monocyte distribution width + standard of care could have resulted in a less than or equal to 14.2% reduction (27.9% vs 32.5%) in mortality, a mean reduction of 1.48 days (10.0 vs 11.5 d) in length of stay, and $3,460 ($23,466 vs $26,926) savings per hospitalization. At the hospital level, based on an established national mean of 206 sepsis hospitalizations per hospital per year, earlier identification with monocyte distribution width is predicted to result in a total of $712,783 in annual cost savings per hospital.

CONCLUSIONS

Improved early identification of sepsis using monocyte distribution width along with current standard of care is estimated to improve both clinical and economic outcomes of sepsis patients presenting in the emergency department. Further research is warranted to confirm these model projections.

Diagnosing and Managing Sepsis by Probing the Host Response to Infection: Advances, Opportunities, and Challenges

Sepsis is a major source of mortality and morbidity globally. Accurately diagnosing sepsis remains challenging due to the heterogeneous nature of the disease, and delays in diagnosis and intervention contribute to high mortality rates. Measuring the host response to infection enables more rapid diagnosis of sepsis than is possible through direct detection of the causative pathogen, and recent advances in host response diagnostics and prognostics hold promise for improving outcomes. The current review discusses recent advances in the technologies used to probe the host response to infection, particularly those based on transcriptomics. These are discussed in the context of contemporary approaches to diagnosing and prognosing sepsis, and recommendations are made for successful development and validation of host response technologies.

Rapid antimicrobial susceptibility tests for sepsis; the road ahead

Current methods for antimicrobial susceptibility testing (AST) are too slow to affect initial treatment decisions in the early stages of sepsis, when the prescriber is most concerned to select effective therapy immediately, rather than finding out what will not work 1 or 2 days later. There is a clear need for much faster differentiation between viral and bacterial infection, and AST, linked to earlier aetiological diagnosis, without sacrificing either the accuracy of quantitative AST or the low cost of qualitative AST. Truly rapid AST methods are eagerly awaited, and there are several candidate technologies that aim to improve the targeting of our limited stock of effective antimicrobial agents. However, none of these technologies are approaching the point of care and nor can they be described as truly culture-independent diagnostic tests. Rapid chemical and genomic methods of resistance detection are not yet reliable predictors of antimicrobial susceptibility and often rely on prior bacterial isolation. In order to resolve the trade-off between diagnostic confidence and therapeutic efficacy in increasingly antimicrobial-resistant sepsis, we propose a series of three linked decision milestones: initial clinical assessment (e.g. qSOFA score) within 10 min, initial laboratory tests and presumptive antimicrobial therapy within 1 h, and definitive AST with corresponding antimicrobial amendment within an 8 h window (i.e. the same working day). Truly rapid AST methods therefore must be integrated into the clinical laboratory workflow to ensure maximum impact on clinical outcomes of sepsis, and diagnostic and antimicrobial stewardship. The requisite series of development stages come with a substantial regulatory burden that hinders the translation of innovation into practice. The regulatory hurdles for the adoption of rapid AST technology emphasize technical accuracy, but progress will also rely on the effect rapid AST has on prescribing behaviour by physicians managing the care of patients with sepsis. Early adopters in well-equipped teaching centres in close proximity to large clinical laboratories are likely to be early beneficiaries of rapid AST, while simplified and lower-cost technology is needed to support poorly resourced hospitals in developing countries, with their higher burden of AMR. If we really want the clinical laboratory to deliver a specific, same-day diagnosis underpinned by definitive AST results, we are going to have to advocate more effectively for the clinical benefits of bacterial detection and susceptibility testing at critical decision points in the sepsis management pathway.