Effect of neutrophil CD64 for diagnosing sepsis in emergency department

Early Diagnosis of Sepsis: The Role of Biomarkers and Rapid Microbiological Tests

Sepsis is a medical emergency resulting from a dysregulated response to an infection, causing preventable deaths and a high burden of morbidity. Protocolized and accurate interventions in sepsis are time-critical. Therefore, earlier recognition of cases allows for preventive interventions, early treatment, and improved outcomes. Clinical diagnosis of sepsis by clinical scores cannot be considered an early diagnosis, given that underlying molecular pathophysiological mechanisms have been activated in the preceding hour or days. There is a lack of a widely available tool enhancing preclinical diagnosis of sepsis. Sophisticated technologies for sepsis prediction have several limitations, including high costs. Novel technologies for fast molecular and microbiological diagnosis are focusing on bedside point-of-care combined testing to reach most settings where sepsis represents a challenge.

Effector function and neutrophil cell death in the severity of sepsis with diabetes mellitus

Sepsis, a life-threatening condition resulting from immune dysregulation, is typically triggered by bacterial infections and commonly coexists with diabetes mellitus. Neutrophils are the first responders to infection and require regulated activation to control pathogen and damage-associated molecular patterns. Dysregulation of neutrophil activation leads to uncontrolled inflammatory responses, often observed in both sepsis and diabetes patients. Neutrophil dysregulation, characterized by effector dysfunction and inadequate cell death processes, can serve as a biomarker for assessing sepsis severity, particularly in diabetic patients. This review provides information on the relationship between effector function, neutrophil cell death, and the severity of sepsis in individuals with diabetes mellitus, aiming to shed light on the mechanisms underlying sepsis progression. Topics covered in the review include an overview of effector function of neutrophil cells, mechanisms of neutrophil cell death, and dysregulation of effectors and neutrophil cell death processes in sepsis severity with diabetes mellitus.

Diagnostic and Prognostic Value of Peripheral Neutrophil CD64 Index in Elderly Patients with Community-Acquired Pneumonia

Community-acquired pneumonia (CAP) is a leading cause of hospitalization and mortality in the elderly. The peripheral blood neutrophil CD64 (nCD64) index is increasingly recognized for its association with poor pneumonia prognosis. A comprehensive investigation involving 128 elderly patients diagnosed with CAP, including 96 with non-severe CAP and 32 with severe CAP, from January 2020 to January 2021 was performed. The nCD64 index, CD4+, CD8+, C-reactive protein (CRP), white blood cell (WBC) count, procalcitonin (PCT), neutrophil (NEUT), and B lymphocyte count were determined using flow cytometry. Our findings reveal that patients with severe CAP exhibited significantly higher levels of nCD64 index, NEUT, WBC, CRP, and PCT. Intriguingly, lower CRP, nCD64 index, CURB-65 score, and PCT were associated with a higher survival rate. Notably, the nCD64 index demonstrated remarkable predictive efficiency for 28-d survival in CAP patients [area under the curve (AUC) = 0.907], surpassing other markers and even showing enhanced predictive power when combined with the CURB-65 score (AUC = 0.905). Furthermore, a negative association was observed between the nCD64 index and both CD4+, CD4+/CD8+ ratios, and B lymphocytes, highlighting its potential role in immune dysregulation. These findings underscore the critical importance of the nCD64 index in the early diagnosis, risk stratification, and prognostic evaluation of infections and immune responses in elderly CAP patients.

An integrative model with HLA-DR, CD64, and PD-1 for the diagnostic and prognostic evaluation of sepsis

BACKGROUND

Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection and progressive immunosuppression with high mortality. HLA-DR, CD64, and PD-1 were assumed to be useful biomarkers for sepsis prediction. However, the ability of a combination of these biomarkers has not been clarified.

METHODS

An observational case-control study was conducted that included 30 sepsis patients, 30 critically ill patients without sepsis admitted to the intensive care unit (ICU), and 32 healthy individuals. The levels of HLA-DR, CD64, and PD-1 expression in peripheral blood immune cells and subsets was assayed on Days 1, 3, and 5, and the clinical information of patients was collected. We compared these biomarkers between groups and evaluated the predictive validity of single and combined biomarkers on sepsis mortality.

RESULTS

The results indicate that PD-1 expression on CD4- CD8- T (PD-1+ CD4- CD8- T) (19.19% ± 10.78% vs. 9.88% ± 1.79%, p = .004) cells and neutrophil CD64 index (nCD64 index) (9.15 ± 5.46 vs. 5.33 ± 2.34, p = .001) of sepsis patients were significantly increased, and HLA-DR expression on monocytes (mHLA-DR+ ) was significantly reduced (13.26% ± 8.06% vs. 30.17% ± 21.42%, p = 2.54 × 10-4 ) compared with nonsepsis critically ill patients on the first day. Importantly, the expression of PD-1+ CD4- CD8- T (OR = 0.622, 95% CI = 0.423-0.916, p = .016) and mHLA-DR+ (OR = 1.146, 95% CI = 1.014-1.295, p = .029) were significantly associated with sepsis mortality. For sepsis diagnosis, the mHLA-DR+ , PD-1+ CD4- CD8- T, and nCD64 index showed the moderate individual performance, and combinations of the three biomarkers achieved greater diagnostic value (AUC = 0.899, 95% CI = 0.792-0.962). When adding PCT into the combined model, the AUC increased to 0.936 (95% CI = 0.840-0.983). For sepsis mortality, combinations of PD-1+ CD4- CD8- T and mHLA-DR+ , have a good ability to predict the prognosis of sepsis patients, with an AUC = 0.921 (95% CI = 0.762-0.987).

CONCLUSION

These findings indicate that the combinations of HLA-DR, CD64, and PD-1 outperformed each of the single indicator in diagnosis and predicting prognosis of sepsis.

Restoring the infected powerhouse: Mitochondrial quality control in sepsis

Sepsis is a dysregulated host response to an infection, characterized by organ failure. The pathophysiology is complex and incompletely understood, but mitochondria appear to play a key role in the cascade of events that culminate in multiple organ failure and potentially death. In shaping immune responses, mitochondria fulfil dual roles: they not only supply energy and metabolic intermediates crucial for immune cell activation and function but also influence inflammatory and cell death pathways. Importantly, mitochondrial dysfunction has a dual impact, compromising both immune system efficiency and the metabolic stability of end organs. Dysfunctional mitochondria contribute to the development of a hyperinflammatory state and loss of cellular homeostasis, resulting in poor clinical outcomes. Already in early sepsis, signs of mitochondrial dysfunction are apparent and consequently, strategies to optimize mitochondrial function in sepsis should not only prevent the occurrence of mitochondrial dysfunction, but also cover the repair of the sustained mitochondrial damage. Here, we discuss mitochondrial quality control (mtQC) in the pathogenesis of sepsis and exemplify how mtQC could serve as therapeutic target to overcome mitochondrial dysfunction. Hence, replacing or repairing dysfunctional mitochondria may contribute to the recovery of organ function in sepsis. Mitochondrial biogenesis is a process that results in the formation of new mitochondria and is critical for maintaining a pool of healthy mitochondria. However, exacerbated biogenesis during early sepsis can result in accumulation of structurally aberrant mitochondria that fail to restore bioenergetics, produce excess reactive oxygen species (ROS) and exacerbate the disease course. Conversely, enhancing mitophagy can protect against organ damage by limiting the release of mitochondrial-derived damage-associated molecules (DAMPs). Furthermore, promoting mitophagy may facilitate the growth of healthy mitochondria by blocking the replication of damaged mitochondria and allow for post sepsis organ recovery through enabling mitophagy-coupled biogenesis. The remaining healthy mitochondria may provide an undamaged scaffold to reproduce functional mitochondria. However, the kinetics of mtQC in sepsis, specifically mitophagy, and the optimal timing for intervention remain poorly understood. This review emphasizes the importance of integrating mitophagy induction with mtQC mechanisms to prevent undesired effects associated with solely the induction of mitochondrial biogenesis.

Neutrophil CD64-a prognostic marker of sepsis in intensive care unit: a prospective cohort study

Background

Little is known about the prognostic ability of nCD64 in critically ill patients. This study aimed to assess the prognostic values of nCD64 in adult ICU patients with sepsis.

Methods

A prospective cohort study was conducted at the ICU of Cho Ray Hospital in Vietnam between January 2019 to September 2020. All newly admitted 86 septic patients diagnosed based on sepsis-3 criteria were included. An evaluation of nCD64 was performed at admission (T0) and 48 h thereafter (T48). Delta nCD64 (nCD64 T48 - nCD64 T0), %delta nCD64 [(nCD64 T48 - nCD64 T0)/nCD64 T0 x 100%], APACHE II and SOFA scores were calculated and examined. Serum procalcitonin levels and white blood cell counts were documented. Spearman's rank correlation coefficient was used to test the correlation between nCD64 and severity scores. Receiver-operating characteristic (ROC) curve was performed to evaluate the predictive efficacy of the sepsis parameters.

Results

Patients with septic shock had significantly higher nCD64 levels than septic patients [3,568 (2,589; 5,999) vs. 1,514 (1,416;2,542) molecules/cell, p < 0.001]. nCD64 T0 and SOFA scores had a moderately positive linear correlation (R = 0.31, p = 0.004). In the survivor group, nCD64 levels significantly decreased within the first 48 h of admission (p < 0.001), while this trend was not statistically significant in the non-survivor group (p = 0.866). The area under the ROC curve (AUC) value of %delta nCD64 combined with APACHE II score (0.81) was higher than that of any other parameter alone or in combination with each other.

Conclusion

The nCD64 index may serve as a valuable biomarker for predicting the course of sepsis. Monitoring changes in nCD64 during the initial 48 h of admission can aid in predicting the prognosis of septic patients. The use of a combination of the trends of nCD64 index in the first 48 h with APACHE II score would further enhance the predictive accuracy. More studies with longer follow-ups are needed to fully understand the implications of serial trend and kinetics of nCD64 in septic patients.

Diagnostic Value of Neutrophil CD64 in Sepsis Patients in the Intensive Care Unit: A Cross-Sectional Study

Little is known about the role of neutrophil CD64 (nCD64) in detecting sepsis early in Asian populations. We examined the cut-off and predictive values of nCD64 for diagnosing sepsis in Vietnamese intensive care units (ICU) patients. A cross-sectional study was conducted at the ICU of Cho Ray Hospital between January 2019 and April 2020. All 104 newly admitted patients were included. Sensitivity (Sens), specificity (Spec), positive and negative predictive values (PPV and NPV), and receiver operating characteristic (ROC) curves were calculated to compare the diagnostic values of nCD64 with those of procalcitonin (PCT) and white blood cell (WBC) for sepsis. The median nCD64 value in sepsis patients was statistically higher than that of non-sepsis patients (3106 [1970-5200] vs. 745 [458-906] molecules/cell, p < 0.001). ROC analysis found that the AUC value of nCD64 was 0.92, which was higher than that of PCT (0.872), WBC (0.637), and nCD64 combined, with WBC (0.906) and nCD64 combined with WBC and PCT (0.919), but lower than that of nCD64 combined with PCT (0.924). With an AUC value of 0.92, the nCD64 index of 1311 molecules/cell-detected sepsis with 89.9% Sens, 85.7% Spec, 92.5% PPV, and 81.1% NPV. nCD64 can be a useful marker for early sepsis diagnosis in ICU patients. nCD64 combined with PCT may improve the diagnostic accuracy.

The Value of Peripheral Blood Leukocyte Parameters in the Early Diagnosis and Clinical Prognosis of Sepsis

Background

Early diagnosis of sepsis is the key to timely, targeted treatment. Cell population data (CPD) has been widely used in many diseases, but its predictive value for early diagnosis and the clinical outcome of sepsis remains unclear. Therefore, this paper discusses whether peripheral blood leukocyte parameters can be used as predictive indicators for early diagnosis and the clinical outcome of sepsis.

Methods

A retrospective study of 45 patients with sepsis, 53 patients with nonseptic infections, and 86 healthy check-ups admitted to Gansu Provincial Hospital from January 2021 to June 2022 was done using a hematology analyzer.

Results

The results of LYMPH#, HFLC#, IG#, NE-WX, LY-WX, LY-WY, and MO-WX showed better diagnostic efficiency in the sepsis group and nonseptic infection group. When the seven differential leukocyte parameters were used to establish diagnostic models, the sensitivity and specificity were 82.20% and 77.40%, respectively. Correlation analysis showed that LYMPH# and HFLC# were positively correlated with PCT (P < 0.05). The clinical outcome of sepsis showed that the leukocyte parameters of discharged WBC and LY-X had better predictive efficacy. When the two differential leukocyte parameters were used to establish diagnostic models, the sensitivity and specificity were 90.90% and 100.00%. Cox regression analysis showed that leukocyte parameters of discharged WBC and LY-X were independent predictors of clinical outcomes (P < 0.05).

Conclusion

Leucocyte parameters HFLC#, IG#, NE-WX, LY-WX, LY-WY, and MO-WX had a certain auxiliary effect on the early diagnosis of sepsis leukocyte parameters of discharged WBC and LY-X were independent predictors of clinical outcomes in patients with sepsis. Therefore, peripheral blood leukocyte parameters may have predictive value for early diagnosis and the clinical outcome of sepsis, but large-scale retrospective studies are still needed to prove our preliminary results.

Pathophysiology of Sepsis and Genesis of Septic Shock: The Critical Role of Mesenchymal Stem Cells (MSCs)

The treatment of sepsis and septic shock remains a major public health issue due to the associated morbidity and mortality. Despite an improvement in the understanding of the physiological and pathological mechanisms underlying its genesis and a growing number of studies exploring an even higher range of targeted therapies, no significant clinical progress has emerged in the past decade. In this context, mesenchymal stem cells (MSCs) appear more and more as an attractive approach for cell therapy both in experimental and clinical models. Pre-clinical data suggest a cornerstone role of these cells and their secretome in the control of the host immune response. Host-derived factors released from infected cells (i.e., alarmins, HMGB1, ATP, DNA) as well as pathogen-associated molecular patterns (e.g., LPS, peptidoglycans) can activate MSCs located in the parenchyma and around vessels to upregulate the expression of cytokines/chemokines and growth factors that influence, respectively, immune cell recruitment and stem cell mobilization. However, the way in which MSCs exert their beneficial effects in terms of survival and control of inflammation in septic states remains unclear. This review presents the interactions identified between MSCs and mediators of immunity and tissue repair in sepsis. We also propose paradigms related to the plausible roles of MSCs in the process of sepsis and septic shock. Finally, we offer a presentation of experimental and clinical studies and open the way to innovative avenues of research involving MSCs from a prognostic, diagnostic, and therapeutic point of view in sepsis.

Diagnostic performance of Neutrophil CD64 index, procalcitonin, and C-reactive protein for early sepsis in hematological patients

BACKGROUND

Patients with hematological diseases are immunosuppressed due to various factors, including the disease itself and treatments, such as chemotherapy and immunotherapy, and are susceptible to infection. Infections in these patients often progress rapidly to sepsis, which is life-threatening.

AIM

To evaluate the diagnostic efficacy of the neutrophil CD64 (nCD64) index, compared to procalcitonin (PCT) and high-sensitivity C-reactive protein (hs-CRP), for the identification of early sepsis in patients with hematological diseases.

METHODS

This was a prospective analysis of patients with hematological diseases treated at the Fuxing Hospital affiliated with Capital Medical University, between March 2014 and December 2018. The nCD64 index was quantified by flow cytometry and the Leuko64 assay software. The factors which may affect the nCD64 index levels were compared between patients with different infection statuses (local infection, sepsis, and no infection), and the control group and the nCD64 index levels were compared among the groups. The diagnostic efficacy of the nCD64 index, PCT, and hs-CRP for early sepsis was evaluated among patients with hematological diseases.

RESULTS

A total of 207 patients with hematological diseases (non-infected group, n = 50; locally infected group, n = 67; sepsis group, n = 90) and 26 healthy volunteers were analyzed. According to the absolute neutrophil count (ANC), patients with hematological diseases without infection were divided into the normal ANC, ANC reduced, and ANC deficiency groups. There was no statistically significant difference in the nCD64 index between these three groups (P = 0.586). However, there was a difference in the nCD64 index among the non-infected (0.74 ± 0.26), locally infected (1.47 ± 1.10), and sepsis (2.62 ± 1.60) groups (P < 0.001). The area under the diagnosis curve of the nCD64 index, evaluated as the difference between the sepsis and locally infected group, 0.777, which was higher than for PCT (0.735) and hs-CRP (0.670). The positive and negative likelihood ratios were also better for the nCD64 index than either PCT and hs-CRP.

CONCLUSION

Our results indicate the usefulness of the nCD64 index as an inflammatory marker of early sepsis in hematological patients.

Biomarkers for sepsis: more than just fever and leukocytosis-a narrative review

A biomarker describes a measurable indicator of a patient's clinical condition that can be measured accurately and reproducibly. Biomarkers offer utility for diagnosis, prognosis, early disease recognition, risk stratification, appropriate treatment (theranostics), and trial enrichment for patients with sepsis or suspected sepsis. In this narrative review, we aim to answer the question, "Do biomarkers in patients with sepsis or septic shock predict mortality, multiple organ dysfunction syndrome (MODS), or organ dysfunction?" We also discuss the role of pro- and anti-inflammatory biomarkers and biomarkers associated with intestinal permeability, endothelial injury, organ dysfunction, blood–brain barrier (BBB) breakdown, brain injury, and short and long-term mortality. For sepsis, a range of biomarkers is identified, including fluid phase pattern recognition molecules (PRMs), complement system, cytokines, chemokines, damage-associated molecular patterns (DAMPs), non-coding RNAs, miRNAs, cell membrane receptors, cell proteins, metabolites, and soluble receptors. We also provide an overview of immune response biomarkers that can help identify or differentiate between systemic inflammatory response syndrome (SIRS), sepsis, septic shock, and sepsis-associated encephalopathy. However, significant work is needed to identify the optimal combinations of biomarkers that can augment diagnosis, treatment, and good patient outcomes.

Intestinal microcirculation dysfunction in sepsis: pathophysiology, clinical monitoring, and therapeutic interventions

BACKGROUND

Intestinal microcirculation dysfunction is an important factor that causes poor prognosis in sepsis patients and is an important pathophysiological basis for the occurrence and development of sepsis.

DATA RESOURCES

PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) were searched from inception to August 1, 2021. The search was limited to the English language only. Two reviewers independently identified studies related to intestinal microcirculation dysfunction in sepsis. Exclusion criteria were duplicate articles according to multiple search criteria.

RESULTS

Fifty articles were included, and most of them were animal studies. These studies reported pathogenesis, including endothelial dysfunction, leukocyte recruitment and adhesion, microthrombus formation, microcirculation hypoperfusion, and redistribution of intestinal wall blood flow. The monitoring methods of intestinal microcirculation were also diverse, including handheld microscopes, intravital microscopy (IVM), laser Doppler blood flow instruments, laser speckle contrast imaging, tissue reflectance spectrophotometry, biochemical markers of intestinal ischemia, and histopathological examination. In view of the related pathogenesis of intestinal microcirculation disorder in sepsis, existing studies also have different opinions on its treatment.

CONCLUSIONS

Limited by monitoring, there are few clinical studies on intestinal microcirculation dysfunction in sepsis. Related research mainly focuses on basic research, but some progress has also been made. Therefore, this review may provide a reference for future research on intestinal microcirculation dysfunction in sepsis.

Diagnostic Value of Neutrophil CD64 in Burn Patients With Infection in Chinese Population: A Systematic Review and Meta-analysis

Infection is one of the leading causes of death in burn patients. Many researchers regard neutrophil CD64 (nCD64) as a biomarker in the early diagnosis of burn patients with infection. Nevertheless, the conclusions are controversial. A comprehensive analysis of the diagnostic value of nCD64 for burn infection was performed in China using a meta-analysis method. Pubmed, Cochrane Library, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), and China Wanfang databases were searched for studies on nCD64 as a diagnostic biomarker of burn patients with infection from the establishment of the databases to September 29, 2020. The data were analyzed by Stata 15.0 software. Six studies were identified. The results showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.92 (95% confidence interval [CI]: 0.88~0.95), 0.82 (95% CI: 0.76~0.87), 5.10 (95% CI: 3.90~6.80), 0.10 (95% CI: 0.06~0.15), and 52 (95% CI: 29~94), respectively. The area under the curve was 0.94 (95% CI: 0.92~0.94). According to the analysis of the sepsis subgroup, it showed that nCD64 had good diagnostic value in the patients with burn sepsis in Chinese population. Neutrophil CD64 is highly efficient to diagnose burn infection in Chinese population. Therefore, nCD64 could be regarded as a valuable biomarker for the early diagnosis of burn infection in China, especially in patients with burn sepsis. Combined with other diagnostic indexes, nCD64 can be clinically used in the early diagnosis of burn infection to improve the sensitivity and specificity.

Diagnostic Challenges in Sepsis

Purpose of Review

Sepsis is a leading cause of death worldwide. Groundbreaking international collaborative efforts have culminated in the widely accepted surviving sepsis guidelines, with iterative improvements in management strategies and definitions providing important advances in care for patients. Key to the diagnosis of sepsis is identification of infection, and whilst the diagnostic criteria for sepsis is now clear, the diagnosis of infection remains a challenge and there is often discordance between clinician assessments for infection.

Recent Findings

We review the utility of common biochemical, microbiological and radiological tools employed by clinicians to diagnose infection and explore the difficulty of making a diagnosis of infection in severe inflammatory states through illustrative case reports. Finally, we discuss some of the novel and emerging approaches in diagnosis of infection and sepsis.

Summary

While prompt diagnosis and treatment of sepsis is essential to improve outcomes in sepsis, there remains no single tool to reliably identify or exclude infection. This contributes to unnecessary antimicrobial use that is harmful to individuals and populations. There is therefore a pressing need for novel solutions. Machine learning approaches using multiple diagnostic and clinical inputs may offer a potential solution but as yet these approaches remain experimental.

Host Diagnostic Biomarkers of Infection in the ICU: Where Are We and Where Are We Going?

Purpose of Review

Early identification of infection in the critically ill patient and initiation of appropriate treatment is key to reducing morbidity and mortality. On the other hand, the indiscriminate use of antimicrobials leads to harms, many of which may be exaggerated in the critically ill population. The current method of diagnosing infection in the intensive care unit relies heavily on clinical gestalt; however, this approach is plagued by biases. Therefore, a reliable, independent biomarker holds promise in the accurate determination of infection. We discuss currently used host biomarkers used in the intensive care unit and review new and emerging approaches to biomarker discovery.

Recent Findings

White cell count (including total white cell count, left shift, and the neutrophil-leucocyte ratio), C-reactive protein, and procalcitonin are the most common host diagnostic biomarkers for sepsis used in current clinical practice. However, their utility in the initial diagnosis of infection, and their role in the subsequent decision to commence treatment, remains limited. Novel approaches to biomarker discovery that are currently being investigated include combination biomarkers, host 'sepsis signatures' based on differential gene expression, site-specific biomarkers, biomechanical assays, and incorporation of new and pre-existing host biomarkers into machine learning algorithms.

Summary

To date, no single reliable independent biomarker of infection exists. Whilst new approaches to biomarker discovery hold promise, their clinical utility may be limited if previous mistakes that have afflicted sepsis biomarker research continue to be repeated.

Effects of viral infection and microbial diversity on patients with sepsis: A retrospective study based on metagenomic next-generation sequencing

BACKGROUND

The study aims to investigate the performance of a metagenomic next-generation sequencing (NGS)-based diagnostic technique for the identification of potential bacterial and viral infections and effects of concomitant viral infection on the survival rate of intensive care unit (ICU) sepsis patients.

METHODS

A total of 74 ICU patients with sepsis who were admitted to our institution from February 1, 2018 to June 30, 2019 were enrolled. Separate blood samples were collected from patients for blood cultures and metagenomic NGS when the patients' body temperature was higher than 38 °C. Patients' demographic data, including gender, age, ICU duration, ICU scores, and laboratory results, were recorded. The correlations between pathogen types and sepsis severity and survival rate were evaluated.

RESULTS

NGS produced higher positive results (105 of 118; 88.98%) than blood cultures (18 of 118; 15.25%) over the whole study period. Concomitant viral infection correlated closely with sepsis severity and had the negative effect on the survival of patients with sepsis. However, correlation analysis indicated that the bacterial variety did not correlate with the severity of sepsis.

CONCLUSIONS

Concurrent viral load correlates closely with the severity of sepsis and the survival rate of the ICU sepsis patients. This suggests that prophylactic administration of antiviral drugs combined with antibiotics may be beneficial to ICU sepsis patients.

The Utility of Neutrophil CD64 and Presepsin as Diagnostic, Prognostic, and Monitoring Biomarkers in Neonatal Sepsis

Background

Neonatal septicemia is a critical medical situation; current conventional laboratory methods still have many limitations and diagnostic obstacles. For this purpose, last decades have witnessed a challenge between the battery of sepsis biomarkers including many leukocyte surface antigens, not only for early diagnostic purposes but also for better follow-up and good management of sepsis patients.

Aim

To evaluate the diagnostic, prognostic, and monitoring performance of both neutrophil CD64 (nCD64) and presepsin as sepsis biomarkers compared to each other and to the conventional laboratory sepsis parameters aiming to decide which is the best fitting for routine daily use in neonatal intensive care units (NICUs).

Methods

235 neonates were enrolled from three Egyptian neonatal ICUs, during the period from November 2015 till March 2018; they were classified into two main groups: the control group (n = 102) and the sepsis group (n = 133). Laboratory sepsis evaluation included highly sensitive CRP (hs-CRP), CBC, in addition to nCD64 (flow cytometry technique), and presepsin measurement (CLEIA technique combined with Magtration® technology); the diagnosis was confirmed thereafter by positive blood culture results (BacT/Alert system). Sixty-two of the enrolled sepsis neonates were subjected to follow-up assessment; they were reclassified according to their clinical improvement at the second time assessment into (group 1: sepsis group without improvement) (n = 20) and (group 2: improved sepsis group) (n = 42).

Results

Significant increase in nCD64 and presepsin values was found in sepsis groups compared to the controls. At cutoff 41.6%, nCD64% could discriminate the presence of septicemia with sensitivity 94.7%, specificity 93.6 %, and AUC 0.925, while presepsin at cutoff 686 pg/ml achieves sensitivity 82.7%, specificity 95.5%, and AUC 0.887, respectively. Significant increase in nCD64 (P < 0.001) and hs-CRP (P=0.018) values was observed in severe sepsis/septic shock patients compared to nonsevere sepsis patients. Delta change percentage (dC%) between initial and follow-up evaluations for both improved and nonimproved sepsis patients was dC Z value −5.904 for nCD64% followed by dC Z value −4.494 for presepsin.

Conclusion

nCD64 and presepsin are valuable early diagnostic and monitoring sepsis biomarkers; the highest sensitivity could be achieved by a univariant sepsis marker in this study was recorded by the nCD64% biomarker, while the highest specificity was documented by presepsin. Combined measurement of both achieves the highest diagnostic performance in sepsis neonates. Either of CD64 or presepsin combined with hs-CRP associated with better performance than any of them alone. nCD64 carries an additional promising role in reflecting sepsis prognosis.

Evaluating the Timeliness and Specificity of CD69, CD64, and CD25 as Biomarkers of Sepsis in Mice

ABSTRACT

Sepsis occurs when an infection induces a dysregulated immune response, and is most commonly bacterial in origin. This condition requires rapid treatment for successful patient outcomes. However, the current method to confirm infection (blood culture) requires up to 48 h for a positive result and many true cases remain culture-negative. Therefore, new diagnostic tests are urgently needed. Recent clinical studies suggest that CD69, CD64, and CD25 may serve as useful biomarkers of sepsis. In this study, we evaluated the cecal ligation and puncture and cecal slurry mouse models as tools to study these biomarkers in young and aged mice, and elucidate the timeliness and specificity of sepsis diagnosis. Fluorescence-activated cell sorting analysis revealed that all three biomarkers were elevated on blood leukocytes during sepsis. CD69 was specifically upregulated during sepsis, while CD64 and CD25 were also transiently upregulated in response to sham surgery. The optimal biomarker, or combination of biomarkers, depended on the timing of detection, mouse age, and presence of surgery. CD69 demonstrated an excellent capacity to distinguish sepsis, and in some scenarios the diagnostic performance was enhanced by combining CD69 with CD64. We also analyzed biomarker expression levels on specific cell populations (lymphocytes, monocytes, and neutrophils) and determined the cell types that upregulate each biomarker. Elevations in blood biomarkers were also detected via microfluidic analyses; in this case CD64 distinguished septic mice from naive controls. Our results suggest that CD69 and CD64 are valuable biomarkers to rapidly detect sepsis, and that mouse models are useful to study and validate sepsis biomarkers.

An Update on Sepsis Biomarkers

Sepsis is a dysregulated systemic reaction to a common infection, that can cause life-threatening organ dysfunction. Over the last decade, the mortality rate of patients with sepsis has decreased as long as patients are treated according to the recommendations of the Surviving Sepsis Campaign, but is still unacceptably high. Patients at risk of sepsis should therefore be identified prior to the onset of organ dysfunction and this requires a rapid diagnosis and a prompt initiation of treatment. Unfortunately, there is no gold standard for the diagnosis of sepsis and traditional standard culture methods are time-consuming. Recently, in order to overcome these limitations, biomarkers which could help in predicting the diagnosis and prognosis of sepsis, as well as being useful for monitoring the response to treatments, have been identified. In addition, recent advances have led to the development of newly identified classes of biomarkers such as microRNAs, long-non-coding RNAs, and the human microbiome. This review focuses on the latest information on biomarkers that can be used to predict the diagnosis and prognosis of sepsis.