Comparison of Fcγ receptor expression on neutrophils with procalcitonin for the diagnosis of sepsis in critically ill patients

Navigating the Modern Landscape of Sepsis: Advances in Diagnosis and Treatment

Sepsis poses a significant threat to human health due to its high morbidity and mortality rates worldwide. Traditional diagnostic methods for identifying sepsis or its causative organisms are time-consuming and contribute to a high mortality rate. Biomarkers have been developed to overcome these limitations and are currently used for sepsis diagnosis, prognosis prediction, and treatment response assessment. Over the past few decades, more than 250 biomarkers have been identified, a few of which have been used in clinical decision-making. Consistent with the limitations of diagnosing sepsis, there is currently no specific treatment for sepsis. Currently, the general treatment for sepsis is conservative and includes timely antibiotic use and hemodynamic support. When planning sepsis-specific treatment, it is important to select the most suitable patient, considering the heterogeneous nature of sepsis. This comprehensive review summarizes current and evolving biomarkers and therapeutic approaches for sepsis.

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.

Early and Effective Diagnosis of Sepsis Using Flow Cytometry

Objective Sepsis is a major global health issue due to its high death and morbidity rates. To avoid the negative effects of sepsis and decrease mortality, it is vital to diagnose and treat it as soon as possible. Blood cultures can take up to 2 days to give result, and they are not always reliable. According to recent studies, neutrophil CD64 expression might be a sensitive and specific option for assessing sepsis. This study aimed to evaluate the diagnostic performance of a flow cytometry analysis for the expression of neutrophil CD64 in sepsis and its comparison with other standard tests in a tertiary care center.

Materials and Methods Prospective analysis on 40 blood samples from suspected sepsis patients admitted to intensive care units with criteria for the systemic inflammatory response syndrome on presentation was performed for expression of neutrophil CD64, C-reactive protein, procalcitonin, and complete blood count. Ten healthy volunteers were also enrolled in this prospective study. The laboratory results were compared in different groups.

Results The neutrophil CD64 had the highest diagnostic value to differentiate between patients of sepsis and nonsepsis groups with a sensitivity of 100% (95% confidence interval [CI]: 77.19–100%) and 100% (95% CI: 55.32–86.83%); specificity of 90.00% (95% CI: 59.58–99.49%) and 87.24% (95% CI: 66.69–99.61%); and likelihood ratio of 10.00 and 7.84, respectively.

Conclusion The neutrophil CD64 expression provides a more sensitive, specific, and novel marker for the early detection of sepsis in critically ill patients.

Rapid detection of bacterial infection using a novel single-tube, four-colour flow cytometric method: Comparison with PCT and CRP

BACKGROUND

A key factor behind the unnecessary use of antibiotics is the lack of rapid and accurate diagnostic tests. In this study, we developed a novel and fast flow cytometric single-tube method to detect bacterial infections within 30 minutes.

METHODS

Quantitative flow cytometric four-colour analysis of host biomarkers CD35, CD64, CD329, and MHC class I expression on neutrophils and lymphocytes was performed on samples taken from 841 febrile patients with suspected infection. Obtained data was incorporated into the four-colour bacterial infection (FCBI)-index, using the developed bacterial infection algorithm.

FINDINGS

In distinguishing between microbiologically confirmed bacterial (n = 193) and viral (n = 291) infections, the FCBI-index method was superior to serum C-reactive protein (CRP) and procalcitonin (PCT). In 269 confirmed viral respiratory tract infections, 43% (95% CI: 37-49%) of the patients had an increased FCBI-index, suggesting probable bacterial coinfection.

INTERPRETATION

The proposed FCBI-index test might be a potent additional tool when assessing appropriateness of empiric antibiotic treatment.

FUNDING

This study has been financially supported by Turku University Hospital (Turku, Finland) and The Finnish Medical Foundation.

Diagnostic value of neutrophil CD64, procalcitonin, and interleukin-6 in sepsis: a meta-analysis

Background

The aim of the study was to conduct a meta-analysis to evaluate the accuracy of neutrophil CD64, procalcitonin (PCT), and interleukin-6 (IL-6) as markers for the diagnosis of sepsis in adult patients.

Methods

Various databases were searched to collect published studies on the diagnosis of sepsis in adult patients using neutrophil CD64, PCT, and IL-6 levels. Utilizing the Stata SE 15.0 software, forest plots and the area under the summary receiver operating characteristic curves were drawn. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the curve (AUC) were calculated.

Results

Fifty-four articles were included in the study. The pooled sensitivity, specificity, and AUC of neutrophil CD64 for the diagnosis of sepsis were 0.88 (95% confidence interval [CI], 0.81–0.92), 0.88 (95% CI, 0.83–0.91), and 0.94 (95% CI, 0.91–0.96), respectively. The pooled sensitivity, specificity, and AUC of PCT for the diagnosis of sepsis were 0.82 (95% CI, 0.78–0.85), 0.78 (95% CI, 0.74–0.82), and 0.87 (95% CI, 0.83–0.89), respectively. Subgroup analysis showed that the AUC for PCT diagnosis of intensive care unit (ICU) sepsis was 0.86 (95% CI, 0.83–0.89) and the AUC for PCT diagnosis of non-ICU sepsis was 0.82 (95% CI, 0.78–0.85). The pooled sensitivity, specificity, and AUC of IL-6 for the diagnosis of sepsis were 0.72 (95% CI, 0.65–0.78), 0.70 (95% CI, 0.62–0.76), and 0.77 (95% CI, 0.73–0.80), respectively.

Conclusions

Of the three biomarkers studied, neutrophil CD64 showed the highest diagnostic value for sepsis, followed by PCT, and IL-6. On the other hand, PCT showed a better diagnostic potential for the diagnosis of sepsis in patients with severe conditions compared with that in patients with non-severe conditions.

Severe Altered Immune Status After Burn Injury Is Associated With Bacterial Infection and Septic Shock

Introduction: Burn injury is associated with a high risk of death. Whether a pattern of immune and inflammatory responses after burn is associated with outcome is unknown. The aim of this study was to explore the association between systemic immune and inflammatory responses and outcome in severely-ill burn patients.

Materials and Methods: Innate immunity, adaptive immunity, activation and stress and inflammation biomarkers were collected at admission and days 2, 7, 14, and 28 in severely-ill adult burn patients. Primary endpoint was mortality at day 90, secondary endpoint was secondary infections. Healthy donors (HD) served as controls. Multiple Factorial Analysis (MFA) was used to identify patterns of immune response.

Results: 50 patients were included. Age was 49.2 (44.2–54.2) years, total burn body surface area was 38.0% (32.7–43.3). Burn injury showed an upregulation of adaptive immunity and activation biomarkers and a down regulation of innate immunity and stress/inflammation biomarkers. High interleukin-10 (IL-10) at admission was associated with risk of death. However, no cluster of immune/inflammatory biomarkers at early timepoints was associated with mortality. HLA-DR molecules on monocytes at admission were associated with bacterial infections and septic shock. Later altered immune/inflammatory responses in patients who died may had been driven by the development of septic shock.

Conclusion: Burn injury induced an early and profound upregulation of adaptive immunity and activation biomarkers and a down regulation of innate immunity and stress/inflammation biomarkers. Immune and inflammatory responses were associated with bacterial infection and septic shock. Absence of immune recovery patterns was associated with poor prognosis.

Neutrophil CD64 a Diagnostic and Prognostic Marker of Sepsis in Adult Critically Ill Patients: A Brief Review

INTRODUCTION

Sepsis is a life-threatening organ dysfunction with increased incidence of morbidity and mortality. Early diagnosis and prompt therapeutic intervention is the cornerstone of sepsis care. Biomarkers play an important role in sepsis having both diagnostic and prognostic implications. Neutrophil CD64 (nCD64) is a useful candidate biomarker for sepsis. Neutrophil CD64 also known as Fc receptor 1 (FcR1), is a high-affinity receptor present on neutrophils for Fc part of immunoglobulin-G (IgG) heavy chain. Its expression gets strongly upregulated in response to proinflammatory cytokines of infection within 4-6 hours. Neutrophil CD64 integrates function involving both innate and adaptive immune responses. The aim of this review is to present literature about nCD64 as a diagnostic and prognostic marker in patients with sepsis/septic shock.

BACKGROUND

The authors searched articles over 13 years, i.e., from 2006 to 2019. They included articles written in English only and further reviewed the reference list of selected articles to obtain potentially relevant articles. Reviews, letters, commentaries, correspondences, case reports, conference abstracts, expert opinions, editorials, and animal experiments were excluded. Articles involving pediatric patients (≤18 years) were also excluded.

REVIEW RESULTS

Several studies have indicated that nCD64 is a highly sensitive and specific marker for the diagnosis of sepsis. Various combinations of biomarkers have been used with nCD64 for a better diagnostic value. Neutrophil CD64 as a prognostic marker in critically ill patients needs to be explored more. Most of the existing literatures have highlighted its prognostic utility based on single value at enrolment. There are limited literatures on prognostic implications of serial trend and kinetics of nCD64.

CONCLUSION

Neutrophil CD64 is a useful diagnostic and prognostic marker of sepsis in critically ill patients. Additional studies are needed on nCD64 in sepsis based on sepsis-3 criteria. Further trials with large sample size are needed to establish prognostic implications of serial nCD64 trend.

HOW TO CITE THIS ARTICLE

Patnaik R, Azim A, Agarwal V. Neutrophil CD64 a Diagnostic and Prognostic Marker of Sepsis in Adult Critically Ill Patients: A Brief Review. Indian J Crit Care Med 2020;24(12):1242-1250.

Valuable Role of Neutrophil CD64 and Highly Sensitive CRP Biomarkers for Diagnostic, Monitoring, and Prognostic Evaluations of Sepsis Patients in Neonatal ICUs

Background

Neonatal sepsis (NS) is a very critical medical situation associated with high morbidities and mortalities. There is an utmost need for a new tool helping in early diagnosis and proper management of sepsis neonates. Neutrophil CD64 (nCD64) shows a very promising value in this concerning issue.

Aim

Evaluate the diagnostic, monitoring, and prognostic performances of nCD64 and highly sensitive CRP (hs-CRP) in NS as well as the possible best panel of biomarkers that can achieve the most desirable results.

Methods

Patients were enrolled from three neonatal intensive care units (NICUs) (n = 121 patients) and classified according to their initial sepsis evaluation into three groups: disease control group (n = 30), proven sepsis group (n = 17), and clinical sepsis group (n = 74). Laboratory evaluation included hs-CRP, complete blood count (CBC), and blood culture in addition to nCD64 (done by flow cytometry technique). Besides the diagnostic evaluations, follow-up evaluations were done for 40 patients after five days from the first time; patients were reclassified according to their outcome into the improved sepsis neonates' group (n = 26) and sepsis neonates without improvement (n = 14).

Results

Significant increase in nCD64 and hs-CRP results were present in sepsis groups compared to the disease controls (P < 0.001); nCD64 at 43% cutoff value could detect the presence of sepsis with 85.6% sensitivity and 93% specificity. Additionally, delta change percentage (dC%) between improved sepsis neonates and sepsis neonates without improvement showed a significant difference in the levels of both nCD64 (P < 0.001) and hs-CRP (P = 0.001).

Conclusion

Besides the promising diagnostic performance documented by nCD64 which is higher than the other laboratory sepsis biomarkers used routinely in NICUs, nCD64 has a valuable role in sepsis patients' monitoring and prognostic evaluation. hs-CRP was moderate in its diagnostic and monitoring results being less than that achieved by nCD64. Combined measurement of nCD64% and hs-CRP gives better diagnostic and monitoring performance than that achieved by any of them alone.

Neutrophil and monocyte receptor expression in patients with sepsis: implications for diagnosis and prognosis of sepsis

Understanding the complex immune responses in sepsis is crucial to provide insight into the clinical syndrome. We evaluated the changes in the surface receptors of the cells of innate immunity, neutrophils and monocytes, in patients with sepsis. Since sepsis remains a clinical challenge, we aimed to assess the significance of altered receptor expression in diagnosis and prognosis. Critically ill patients with sepsis (n=31) were investigated for the expression of receptors for IgG heavy chain CD64 and CD16 on neutrophils and CD64 and the lipopolysaccharide receptor CD14 on monocytes by flow cytometry and compared to 23 patients with no sepsis. Patients with sepsis had increased expression of neutrophil CD64. Neutrophil CD64 was specific for discriminating patients with sepsis but showed weak sensitivity. When integrated in a scoring system, neutrophil CD64 in combination with C-reactive protein (CRP) and SOFA score showed a diagnostic accuracy of 0.93 for sepsis and significantly predicted increased mortality risk. While neutrophil CD16 did not discriminate for sepsis, decreased expression was associated with increased mortality risk. In contrast, monocyte CD64 and CD14 expression was unaltered in sepsis and was not associated with mortality risk. Our study demonstrates that unlike monocytes, neutrophil receptor expression is altered in patients with sepsis receiving intensive care. It is promising to apply a combination approach to diagnose sepsis especially in time-limited conditions.

Effect of neutrophil CD64 for diagnosing sepsis in emergency department

BACKGROUND

The aim of this study is to investigate the diagnostic and prognostic value of neutrophil CD64 (nCD64) as a novel biomarker in sepsis patients.

METHODS

One hundred fifty-one adult patients diagnosed with sepsis and 20 age-matched healthy controls were enrolled in the study. Patients with sepsis were further subdivided into a sepsis group and a septic shock group. nCD64 expression, serum procalcitonin (PCT) level, C-reactive protein (CRP) level, and white blood cell (WBC) count were obtained for each patient, and Sequential Organ Failure Assessment (SOFA) scores were calculated.

RESULTS

nCD64 expression was higher in the sepsis group with confirmed infection than in the control group. The receiver operating characteristic (ROC) curve of nCD64 was higher than those of SOFA score, PCT, CRP and WBC for diagnosing infection. The area under the curve (AUC) of nCD64 combined with SOFA score was the highest for all parameters. The AUC of nCD64 for predicting 28-day mortality in sepsis was significantly higher than those of PCT, CRP, and WBC, but slightly lower than that of SOFA score. The AUC of nCD64 or PCT combined with SOFA score was significantly higher than that of any single parameter for predicting 28-day mortality.

CONCLUSION

nCD64 expression and SOFA score are valuable parameters for early diagnosis of infection and prognostic evaluation of sepsis patients.

Biomarkers in Pneumonia-Beyond Procalcitonin

Pneumonia is the leading infectious cause of mortality worldwide and one of the most common lower respiratory tract infections that is contributing significantly to the burden of antibiotic consumption. Due to the complexity of its pathophysiology, it is widely accepted that clinical diagnosis and prognosis are inadequate for the accurate assessment of the severity of the disease. The most challenging task for a physician is the risk stratification of patients with community-acquired pneumonia. Herein, early diagnosis is essential in order to reduce hospitalization and mortality. Procalcitonin and C-reactive protein remain the most widely used biomarkers, while interleukin 6 has been of particular interest in the literature. However, none of them appear to be ideal, and the search for novel biomarkers that will most sufficiently predict the severity and treatment response in pneumonia has lately intensified. Although our insight has significantly increased over the last years, a translational approach with the application of genomics, metabolomics, microbiomics, and proteomics is required to better understand the disease. In this review, we discuss this rapidly evolving area and summarize the application of novel biomarkers that appear to be promising for the accurate diagnosis and risk stratification of pneumonia.

Uso de procalcitonina como diagnóstico de sepsis o shock séptico: revisión sistemática y metaanálisis

Introducción: La procalcitonina (PCT) es una prohormona de la calcitonina, producida por las células C de la glándula tiroides y convertida intracelularmente por enzimas proteolíticas en la hormona activa. La producción de PCT durante procesos inflamatorios, está ligada a endotoxinas bacterianas y a citoquinas inflamatorias. La mortalidad por sepsis, depende en gran medida de la detección precoz y del inicio de una terapia adecuada, incluyendo la administración de antibióticos apropiados, sin embargo, no está claro si el rendimiento diagnóstico de la PCT en el contexto de la nueva definición de sepsis en el tercer consenso es igual que con la definición previa.Métodos: Se incluyeron estudios que describieran el uso de PCT dentro de las primeras 24 horas de admisión, como prueba diagnóstica de sepsis. Se realizó la búsqueda en las bases de datos de Medline (Pubmed) y Embase. La calidad metodológica se evaluó según la Colaboración Cochrane en el desarrollo de Revisiones Sistemáticas sobre Test de Análisis para la herramienta QUADAS-II. El sesgo de publicación fue estudiado con el Test de Asimetría de Deeks. Se usó el módulo de MIDAS de STATA 14 para el análisis univariado y la construcción de la Curva de ROC.Resultados: Se obtuvieron 2076 registros (783 de Medline y 1293 de Embase). De los 12 estudios seleccionados, se incluyeron un total de 1353 pacientes, con una prevalencia en los estudios revisados entre el 9% y 88%, con un promedio del 47%. La Sensibilidad agrupada fue 0,83% (IC95% (0,74-0,89)) y la Especificidad fue 0,84% (IC95%(0,76-0,89)). El área bajo la Curva fue 0,90 (IC95%(0,87-0,92)). La heterogeneidad entre los estudios es importante I2 88% (IC95%(77-100)). Existe un sesgo de publicación según el test de Deek, con resultado P=0,04. En el análisis sobre la Probabilidad Post test según el nomograma de Fagan, es del 56%, teniendo en cuenta una probabilidad pretest del 20% según el LR positivo 5.Conclusión: La PCT es una prueba diagnóstica con buen rendimiento para sepsis o shock séptico, en pacientes adultos, no gestantes. Aunque hay sesgo de publicación y una gran heterogeneidad en los resultados, la prueba se considera adecuada para el escenario de sepsis según las nuevas definiciones.

Comparison of the accuracy of neutrophil CD64, procalcitonin, and C-reactive protein for sepsis identification: a systematic review and meta-analysis

Background

Neutrophil CD64 is widely described as an accurate biomarker for the diagnosis of infection in patients with septic syndrome. We performed a systematic review and meta-analysis to evaluate the diagnostic accuracy of neutrophil CD64, comparing it with C-reactive protein (CRP) and procalcitonin (PCT) for the diagnosis of infection in adult patients with septic syndrome, based on sepsis-2 criteria. We searched the PubMed and Embase databases and Google Scholar. Original studies reporting the performance of neutrophil CD64 for sepsis diagnosis in adult patients were retained. The pooled sensitivity, specificity, diagnostic odds ratio (DOR), and hierarchical summary receiver operating characteristic (SROC) curve were calculated.

Results

We included 14 studies (2471 patients) from 2006 to 2017 in the meta-analysis. The pooled sensitivity and specificity of neutrophil CD64 for diagnosing infection in adult patients with septic syndrome were 0.87 (95% CI 0.80–0.92) and 0.89 (95% CI 0.82–0.93), respectively. The area under the SROC curve and the DOR were 0.94 (95% CI 0.92–0.96) and 53 (95% CI 22–128), respectively. There was significant heterogeneity between the studies included. Subgroup analyses showed that this heterogeneity was due to differences in sample size and the proportions of patients with sepsis included in the studies. Six studies (927 patients) compared neutrophil CD64 and CRP determinations, and six studies (744 patients) compared neutrophil CD64 and PCT determinations. The area under the SROC curve was larger for neutrophil CD64 than for CRP (0.89 [95% CI 0.87–0.92] vs. 0.84 [95% CI 0.80–0.88], P < 0.05) or PCT (0.89 [95% CI 0.84–0.95] vs. 0.84 [95% CI 0.79–0.89], P < 0.05).

Conclusions

In adult patients with septic syndrome, neutrophil CD64 levels are an excellent biomarker with moderate accuracy outperforming both CRP and PCT determinations.

Electronic supplementary material

The online version of this article (10.1186/s13613-018-0479-2) contains supplementary material, which is available to authorized users.

Recent advances in biosensors for diagnosis and detection of sepsis: A comprehensive review

Sepsis is one of the leading causes of mortality among critically ill patients globally. According to WHO report 2018, it is estimated to affect beyond 30 million people worldwide every year. It causes loss of human lives, which arise from infection and inflammation and long term stay in intensive care unit (ICU) in hospitals. Despite the availability of satisfactory prognostic markers contributing to the diagnosis of sepsis, millions of people die even after admission to the hospitals. Correct and early diagnosis of sepsis leads to rapid administration of appropriate antibiotics can thus potentially avert the attainment to critical stages of sepsis, thereby saving human lives. Conventional diagnostic practices are costly, time consuming and they lack adequate sensitivity and selectivity, provoking an urgent need for developing alternate sepsis diagnosis systems. Nevertheless, biosensors have the much-treasured scope for reasonable sepsis diagnosis. Advancement in nano-biotechnology has provided new paradigm for biosensor platforms with upgraded features. Here, we provide an overview of the recent advances in biosensors with a brief introduction to sepsis, followed by the conventional methods of diagnosis and bio-sensing. To conclude, a proactive role and an outlook on technologically advanced biosensor platforms are discoursed with possible biomedical applications.

Diagnosis of sepsis from a drop of blood by measurement of spontaneous neutrophil motility in a microfluidic assay

Current methods for the diagnosis of sepsis have insufficient precision, causing regular misdiagnoses. Microbiological tests can help diagnose sepsis but are usually too slow to have an impact on timely clinical-decision making. Neutrophils have high sensitivity to infections, yet measurements of neutrophil surface markers, genomic changes, and phenotype alterations have had only a marginal effect on sepsis diagnosis. Here, we report a microfluidic assay that measures the spontaneous motility of neutrophils in the context of plasma, in one droplet of blood. We measured the performance of the assay in two independent cohorts of critically ill patients suspected of sepsis. In the first cohort, we developed a machine-learning-based scoring system (sepsis score) that segregated patients with sepsis from those without sepsis. In the second cohort, we validated the sepsis score in a double-blinded, prospective case-control study. For the 42 patients across the two cohorts, the assay identified sepsis patients with 97% sensitivity and 98% specificity. The neutrophil assay could potentially be used to accurately diagnose and monitor sepsis in larger populations of at-risk patients.

Correlation of Neutrophil CD64 with Clinical Profile and Outcome of Sepsis Patients during Intensive Care Unit Stay

Introduction:

Neutrophil CD64 (nCD64) has been found to identify sepsis from nonseptic patients. It is also reported to be a predictor of survival and severity of sepsis. The goal of this study was to correlate serial nCD64 with Intensive Care Unit (ICU) outcome and severity of sepsis.

Materials and Methods:

A prospective observational study was conducted in 12-bedded critical care unit of a tertiary care center. Adult patients with sepsis were included in this study. Demographics, illness severity scores, clinical parameters, laboratory data, and 28-day outcome were recorded. Serial nCD64 analysis was done (on days 0, 4, and 8) in consecutive patients.

Results:

Fifty-one consecutive patients were included in the study. Median Acute Physiology and Chronic Health Evaluation II was 16 (12–20) and mean Sequential Organ Failure Assessment was 9 (8–10). Compared to survivors, nonsurvivors had higher nCD64 on day 8 (P = 0.001). nCD64 was higher in the septic shock group compared to sepsis group on days 0 and 8 (P < 0.05). Survivors showed improving trend of nCD64 over time while nonsurvivors did not. This trend was similar in the presence or absence of septic shock. nCD64 count was a good predictor of the septic shock on day 0 (area under the curve [AUC] = 0.747, P = 0.010) and moderate predictor at day 8 (AUC = 0.679, P = 0.028).

Conclusion:

Monitoring serial nCD64 during ICU stay may be helpful in determining the clinical course of septic patients.

Neutrophil CD64, C-reactive protein, and procalcitonin in the identification of sepsis in the ICU - Post-test probabilities

PURPOSE

We were interested in whether C-reactive protein (CRP) and procalcitonin (PCT) distinguish sepsis from non-septic controls and whether a combination of CRP, PCT, and neutrophil CD64 improves identification of sepsis in the intensive care unit (ICU).

MATERIALS AND METHODS

We analyzed the CRP and PCT concentrations from 27 patients with sepsis and 15 ICU controls. In addition, CD64 on neutrophils was measured using quantitative flow cytometry. We present a multiple marker analysis for sepsis diagnostics combining neutrophil CD64, CRP, and PCT using post-test analysis.

RESULTS

The CRP and PCT values separated sepsis and non-septic ICU patients. In post-test analysis, CRP provided a positive probability of 0.48 and a negative probability of 0.053 for sepsis in the ICU; while, the corresponding values were 0.35 and 0.0059, respectively, for PCT and 0.62 and 0.0013, respectively, for neutrophil CD64. When neutrophil CD64 was analyzed with PCT and CRP, the probabilities were 0.98 and <0.001, respectively.

CONCLUSIONS

Neutrophil CD64 expression was superior to PCT and CRP for the identification of sepsis in ICU. Positive post-test probability for any combinations of simultaneously analyzed CRP, PCT and CD64 showed improved diagnostic accuracy for sepsis. This approach may be useful for guiding antibiotic treatment in ICU.

Biomarkers for diagnosis of sepsis in patients with systemic inflammatory response syndrome: a systematic review and meta-analysis

Background

Sepsis is one of the most common diseases that seriously threaten human health. Although a large number of markers related to sepsis have been reported in the last two decades, the diagnostic accuracy of these biomarkers remains unclear due to the lack of similar baselines among studies. Therefore, we conducted a large systematic review and meta-analysis to evaluate the diagnostic value of biomarkers from studies that included non-infectious systemic inflammatory response syndrome patients as a control group.

Methods

We searched Medline, Embase and the reference lists of identified studies beginning in April 2014. The last retrieval was updated in September 2016.

Results

Ultimately, 86 articles fulfilled the inclusion criteria. Sixty biomarkers and 10,438 subjects entered the final analysis. The areas under the receiver operating characteristic curves for the 7 most common biomarkers, including procalcitonin, C-reactive protein, interleukin 6, soluble triggering receptor expressed on myeloid cells-1, presepsin, lipopolysaccharide binding protein and CD64, were 0.85, 0.77, 0.79, 0.85, 0.88, 0.71 and 0.96, respectively. The remaining 53 biomarkers exhibited obvious variances in diagnostic value and methodological quality.

Conclusions

Although some biomarkers displayed moderate or above moderate diagnostic value for sepsis, the limitations of the methodological quality and sample size may weaken these findings. Currently, we still lack an ideal biomarker to aid in the diagnosis of sepsis. In the future, biomarkers with better diagnostic value as well as a combined diagnosis using multiple biomarkers are expected to solve the challenge of the diagnosis of sepsis.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-3591-5) contains supplementary material, which is available to authorized users.

Neutrophil CD64 expression as a longitudinal biomarker for severe disease and acute infection in critically ill patients

INTRODUCTION

Neutrophilic granulocytes express cluster of differentiation 64 (CD64) antigen upon activation. CD64 can be used as a marker of bacterial infection and sepsis. The goal of this study was to determine whether CD64 is a useful biomarker for critically ill patients and analyze longitudinal measurements with regard to outcome and sepsis severity.

METHODS

In this prospective observational study, CD64 analysis was performed daily until discharge from ICU or death. Demographics, clinical, laboratory data, and outcome defined as 28-day survival were recorded. Patients were included when admitted to the ICU with sepsis, severe sepsis, or septic shock and within 24 h from start of antibiotic treatment.

RESULTS

Hundred and fifty-five consecutive patients were enrolled. At baseline, a difference in CD64 of 2.26 (1.33-4.47) vs. 1.49 (0.89-2.24) (P = 0.004) was seen between patients with a positive culture and negative culture. CD64 at day 1 was higher with patients with septic shock when compared with sepsis (P = 0.012). No difference of CD64 between survivors and nonsurvivors was seen.

CONCLUSION

This study demonstrated that CD64 discriminates between critically ill patients with culture positive and negative sepsis and correlates with severity of disease. However, CD64 index is not a good predictor for 28-day mortality in the critically ill patient.

Impact of T cell activation, HIV replication and hepatitis C virus infection on neutrophil CD64 expression

BACKGROUND

Overexpression of the Fc receptor CD64 on neutrophils is associated with innate immune response and bacterial infections. During HIV infection a large set of immune disorders including T-lymphocyte over-activation, microbial translocation, impairment of neutrophil functions, and immunodeficiency may interplay with neutrophil CD64 expression.

METHODS

Associations of neutrophil CD64 expression with CD8⁺ T cell activation, CD4⁺ T cells number, HIV, and HCV replications were investigated in HIV infected patients using a standardized method.

RESULTS

Higher neutrophil CD64 expression was observed in HIV infected subjects compared to healthy controls (0.91 vs. 0.75, P < 0.001). Among 115 HIV infected patients, nine (8.8%) had a CD64 expression over the clinical threshold as calculated against bead standard (i.e., 1.5). HIV viremic patients were more likely to have an index above 1.5 (OR: 6.68, P values: 0.01). A trend for correlation between CD64 expression and CD8 T cell activation was observed (P values: 0.08). Blood CD4⁺ T lymphocyte depletion and HCV replication did not affect neutrophil CD64 expression.

CONCLUSIONS

HIV infection and HIV replication are associated with up-regulation of neutrophil CD64. CD64 overexpression above the clinical threshold was observed in a minor proportion of HIV infected individuals treated by antiretroviral therapy and may be a marker of neutrophil activation related to non-AIDS-linked comorbidities. © 2016 International Clinical Cytometry Society.

Determination of neutrophil CD64 expression as a prognostic biomarker in patients with community-acquired pneumonia

The expression of CD64 in neutrophils (nCD64) has shown utility in the diagnosis of sepsis. The aim of this study was to assess the usefulness of nCD64 expression to identify patients with community-acquired pneumonia (CAP) at risk of a poor outcome. A prospective study of nCD64 expression (determined by flow cytometry) in patients with CAP was performed. The sensitivity/specificity of nCD64 in predicting poor outcome [defined as intensive care unit (ICU) admission and/or clinical deterioration after arrival at the emergency department] was calculated. Eighty-three adults with CAP were included; 14.5 % had septic shock, 19.3 % required ICU admission, and 10.8 % presented clinical deterioration after admission. The mean of the median fluorescence intensity (MFI) of nCD64 expression was 1140 (±1097). Patients with nCD64 expression ≥2700 MFI had more clinical deterioration (36.4 vs. 7.2 %, p = 0.015) and more ICU admission (45.5 vs. 14.5 %, p = 0.028). To identify clinical deterioration and ICU admission, nCD64 expression showed a sensitivity of 44.4 and 33.3 % and a specificity of 90.1 and 90.8 %, respectively. The addition of nCD64 expression to the Pneumonia Severity Index and CURB-65 severity scores did not improve the accuracy of predicting these outcomes. Although nCD64 expression is associated with an increased risk of ICU admission or clinical deterioration after admission, its accuracy in predicting these poor outcomes is modest and does not significantly improve the predictive ability of the PSI and CURB-65 severity scores.

Protective Role of Rho Guanosine Diphosphate Dissociation Inhibitor, Ly-GDI, in Pulmonary Alveolitis

Growing evidences indicate that Ly-GDI, an inhibitory protein of Rho GTPases, plays an essential role in regulating actin cytoskeletal alteration which is indispensible for the process such as phagocytosis. However, the role of Ly-GDI in inflammation remains largely unknown. In the current study, we found that Ly-GDI expression was significantly decreased in the IgG immune complex-injured lungs. To determine if Ly-GDI might regulate the lung inflammatory response, we constructed adenovirus vectors that could mediate ectopic expression of Ly-GDI (Adeno-Ly-GDI). In vivo mouse lung expression of Ly-GDI resulted in a significant attenuation of IgG immune complex-induced lung injury, which was due to the decreased pulmonary permeability and lung inflammatory cells, especially neutrophil accumulation. Upon IgG immune complex deposition, mice with Ly-GDI over-expression in the lungs produced significant less inflammatory mediators (TNF-α, IL-6, MCP-1, and MIP-1α) in bronchoalveolar lavage fluid when compared control mice receiving airway injection of Adeno-GFP. Mechanically, IgG immune complex-induced NF-κB activity was markedly suppressed by Ly-GDI in both alveolar macrophages and lungs as measured by luciferase assay and electrophoretic mobility shift assay. These findings suggest that Ly-GDI is a critical regulator of inflammatory injury after deposition of IgG immune complexes and that it negatively regulates the lung NF-κB activity.

Diagnostic accuracy and clinical relevance of an inflammatory biomarker panel for sepsis in adult critically ill patients

The objective of this study was to assess the diagnostic accuracy of C-reactive protein (CRP), procalcitonin (PCT), and cellular immune markers levels in sepsis. This was a prospective observational study in adult intensive care unit (ICU) patients, between 2012 and 2014. The 8-color flow cytometric biomarker panel included CD64, CD163, and HLA-DR. Index test results were compared with sepsis, using receiver operating characteristic curve analyses. Multivariate logistic regression assessed the relationship of sets of markers with the probability of sepsis. Of 219 enrolled patients, 120 had sepsis. C-statistic was the highest for CRP (0.86) followed by neutrophil CD64 expression (0.83), procalcitonin (0.82), and Acute Physiology and Chronic Health Evaluation (APACHE) IV (0.72). After adjustment for APACHE IV, the combination of CRP, PCT, and neutrophil CD64 measure remained a significant predictor of sepsis with an excellent AUC (0.90). In a targeted ICU population at increased risk of sepsis, CRP, PCT, and neutrophil CD64 combined improve the diagnostic accuracy of sepsis.

Expression of CD11c and EMR2 on neutrophils: potential diagnostic biomarkers for sepsis and systemic inflammation

There is a need for cellular biomarkers to differentiate patients with sepsis from those with the non-infectious systemic inflammatory response syndrome (SIRS). In this double-blind study we determined whether the expression of known (CD11a/b/c, CD62L) and putative adhesion molecules [CD64, CD97 and epidermal growth factor (EGF)-like molecule containing mucin-like hormone receptor (EMR2)] on blood neutrophils could serve as useful biomarkers of infection and of non-infectious SIRS in critically ill patients. We studied 103 patients with SIRS, 83 of whom had sepsis, and 50 healthy normal subjects, using flow cytometry to characterize neutrophils phenotypically in whole blood samples. Patients with SIRS had an increased prevalence of neutrophils expressing CD11c, CD64 and EMR2 in comparison with healthy subjects (P < 0.001), but normal expression of CD11a, CD11b, CD62L and CD97. An increase in the percentage of neutrophils bearing CD11c was associated with sepsis, EMR2 with SIRS and CD64 with sepsis and SIRS. Neutrophils expressing CD11c had the highest sensitivity (81%) and specificity (80%) for the detection of sepsis, and there was an association between the percentage of neutrophils expressing EMR2 and the extent of organ failure (P < 0.05). Contrary to other reports, we did not observe an abnormal expression of CD11b or CD62L on neutrophils from patients with SIRS, and suggest that this discrepancy is due to differences in cell processing protocols. We propose that blood neutrophils expressing CD11c and EMR2 be considered as potential biomarkers for sepsis and SIRS, respectively.

Prognostic Value and Daily Trend of Interleukin-6, Neutrophil CD64 Expression, C-Reactive Protein and Lipopolysaccharide-Binding Protein in Critically Ill Patients: Reliable Predictors of Outcome or Not?

Background

Severe sepsis and/or trauma complicated by multiple organ dysfunction syndrome are the leading causes of death in critically ill patients. The aim of this prospective single-centre study was to assess the prognostic value and daily trend of interleukin-6 (IL-6), neutrophil CD64 expression, C-reactive protein (CRP) and lipopolysaccharide-binding protein (LBP) regarding outcome in critically ill patients with severe trauma and/or severe sepsis. Outcome measure was hospital mortality.

Methods

One hundred and two critically ill patients admitted to the intensive care unit of a tertiary university hospital were enrolled in this prospective study. Blood samples were collected on admission (day 1), days 2 and 3.

Results

CD64 index was 1.6-fold higher on day 1 and 1.78-fold higher on day 2 in non-survivors (p<0.05). The area under the curve (AUC) for the CD64 index on day 1 for outcome was 0.727. At a cut-off level of 2.80 sensitivity was 75% and specificity was 65%. Patients with CD64 index level on day 1 higher than 2.80 had 2.4-fold higher probability of dying. Odds ratio is 2.40; 95% CI 0.60–9.67.

Conclusions

CD64 index on day 1 is a fairly good predictor of outcome. AUCs for IL-6, CRP and LBP were < 0.55, suggesting these biomarkers failed to predict outcome.

Neutrophil CD64 Expression as a Diagnostic Marker in Patients Hospitalized with Exacerbations of COPD: A Prospective Observational Study

PURPOSE

The expression of the neutrophil high-affinity Fc-gamma receptor (CD64) can be used as a diagnostic marker for bacterial infection and sepsis. The aims of this study were to determine the diagnostic accuracy of CD64 compared to C-reactive protein (CRP) and white blood cell count (WBC) in patients hospitalized with acute exacerbations of COPD (AECOPD) and to investigate the kinetics of CD64 expression.

METHODS

The present study is a prospective, single-centre observation study. Blood samples were collected from patients hospitalized with AECOPD at admission and after 6, 24 and 48 h. Retrospective reviews on the patients' medical records were performed blinded to the CD64 results. The CD64 was measured using the Leuko64 kit from Trillium Diagnostics, LLC (Maine, USA) with the CELL-DYN Sapphire Haematology System (Abbott Laboratories, Illinois, USA). Diagnostic accuracy of the CD64, CRP and WBC was compared using a receiver operating characteristic (ROC) curve analysis.

RESULTS

A total of 113 patients were included. Thirty-six patients (32 %) had pulmonary infiltrate on chest X-ray at admission (PI). The CD64 was higher in samples from patients with AECOPD and PI than those without PI at admission (median 1.25 vs. 0.60, p = 0.002) and during 48 h of follow-up. The area under the ROC curve of CD64, CRP and WBC was 0.69, 0.73 and 0.64, respectively, (p = 0.42 for the test of difference).

CONCLUSION

Neutrophil CD64 expression has about the same diagnostic accuracy as CRP in diagnosing pneumonia in patients hospitalized with AECOPD, but does not add to the diagnostic accuracy of CRP and WBC count.

Neutrophil CD64 expression as a diagnostic marker for sepsis in adult patients: a meta-analysis

INTRODUCTION

Neutrophil CD64 (nCD64) expression appears to be a promising marker of bacterial infections. The aim of this meta-analysis was to assess the accuracy of nCD64 expression for the diagnosis of sepsis in critically ill adult patients.

METHODS

We systematically searched PubMed, Embase, ISI Web of Knowledge, and the Cochrane Library for literature published between database inception and 19 May 2014, as well as reference lists of identified primary studies. Studies were included if they included assessment of the accuracy of nCD64 expression for sepsis diagnosis in adult patients and provided sufficient information to construct a 2×2 contingency table.

RESULTS

A total of 8 studies comprising 1986 patients fulfilled the inclusion criteria for the final analysis. The pooled sensitivity and specificity were 0.76 (95 % confidence interval [CI], 0.73-0.78) and 0.85 (95 % CI, 0.82-0.87), respectively. The positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio were 8.15 (95 % CI, 3.82-17.36), 0.16 (95 % CI, 0.09-0.30), and 60.41 (95 % CI, 15.87-229.90), respectively. The area under the summary receiver operating characteristic curve of nCD64 expression with Q* value were 0.95 (Q* =0.89).

CONCLUSIONS

On the basis of our meta-analysis, nCD64 expression is a helpful marker for early diagnosis of sepsis in critically ill patients. The results of the test should not be used alone to diagnose sepsis, but instead should be interpreted in combination with medical history, physical examination, and other test results.

Neutrophil CD64 level as a rapid and promising diagnostic tool for infectious diseases in elderly patients

AIM

We examined the utility of the neutrophil CD64 level as a rapid and sensitive diagnostic marker for infections in febrile aged patients.

METHODS

The expression level of CD64 per neutrophil was quantitatively measured with flow cytometry using a QuantiBrite kit in samples from febrile (aged >65 years) patients. Information about the presence or absence of infectious disease was retrospectively obtained from each patient's medical record in which attending physicians were obliged to write down a tentative diagnosis after resolution of manifestations.

RESULTS

With receiver operating characteristic curve evaluation using the results, a CD64 level >2000 molecules per neutrophil was sensitive and specific for detecting infection. Among 102 patients suspected of having infection, 72 patients were diagnosed with infectious diseases, and 30 patients had non-infectious diseases. The sensitivity and specificity of determination of the neutrophil CD64 level were 88% and 63%, respectively. However, considering the high frequency of infections in elderly patients (71% in the present study), the post-test probability reached as high as 93%. The positive likelihood ratio was 2.4, and the negative likelihood ratio was 0.2.

CONCLUSIONS

Considering the frequency of infectious diseases in elderly patients, determination of the neutrophil CD64 level helps detect infectious diseases.

Host response biomarkers in sepsis: the role of procalcitonin

Procalcitonin is the prohormone of calcitonin and present in minute quantities in health. However, during infection, its levels rise considerably and are correlated with the severity of the infection. Several assays have been developed for measurement of procalcitonin levels; in this article, we will briefly present the PCT-sensitive Kryptor(®) test (Brahms, Hennigsdorf, Germany), one of the most widely used assays for procalcitonin in recent studies. Many studies have demonstrated the value of procalcitonin levels for diagnosing sepsis and assessing disease severity. Procalcitonin levels have also been successfully used to guide antibiotic administration. However, procalcitonin is not specific for sepsis, and values need to be interpreted in the context of a full clinical examination and the presence of other signs and symptoms of sepsis.

Diagnostic accuracy of neutrophil CD64 expression in neonatal infection: A meta-analysis

Objective

*Liu-Qun Jia and Yong-Chun Shen contributed equally to this work and are joint first authors. The aim of the present study was to establish the predictive values of neutrophil CD64 expression in diagnosing neonatal infection.

Methods

A comprehensive search of the PubMed and Embase® literature databases identified outcome data from published studies estimating the diagnostic accuracy of neutrophil CD64 expression for neonatal infection. Summary estimates for sensitivity, specificity, diagnostic odds ratios (DOR) and the area under the summary receiver operating characteristic curve (AUC) were calculated using a bivariate random-effects approach.

Results

Twelve studies including 1915 neonates were analysed. Summary estimates (95% confidence intervals) for CD64 expression in the diagnosis of neonatal infection were: sensitivity, 0.78 (0.75, 0.81); specificity, 0.81 (0.78, 0.83); DOR, 21.27 (11.71, 38.65); positive-likelihood ratio, 4.53 (3.22, 6.36); negative-likelihood ratio, 0.23 (0.14, 0.37); AUC, 0.89.

Conclusions

Neutrophil CD64 expression can be used as an additional test in the diagnosis of neonatal infection. Results of a CD64 assay should not be used alone to diagnose such infections, but should be interpreted in combination with other test results and clinical findings.

CD64-Neutrophil expression and stress metabolic patterns in early sepsis and severe traumatic brain injury in children

Background

Critical illness constitutes a serious derangement of metabolism. The aim of our study was to compare acute phase metabolic patterns in children with sepsis (S) or severe sepsis/septic shock (SS) to those with severe traumatic brain injury (TBI) and healthy controls (C) and to evaluate their relations to neutrophil, lymphocyte and monocyte expressions of CD64 and CD11b.

Methods

Sixty children were enrolled in the study. Forty-five children with systemic inflammatory response syndrome (SIRS) were classified into three groups: TBI (n = 15), S (n = 15), and SS (n = 15). C consisted of 15 non- SIRS patients undergoing screening tests for minor elective surgery. Blood samples were collected within 6 hours after admission for flow cytometry of neutrophil, lymphocyte and monocyte expression of CD64 and CD11b (n = 60). Procalcitonin (PCT), C-reactive protein (CRP), glucose, triglycerides (TG), total cholesterol (TC), high (HDL) or low-density-lipoproteins (LDL) were also determined in all groups, and repeated on day 2 and 3 in the 3 SIRS groups (n = 150).

Results

CRP, PCT and TG (p < 0.01) were significantly increased in S and SS compared to TBI and C; glucose did not differ among critically ill groups. Significantly lower were the levels of TC, LDL, and HDL in septic groups compared to C and to moderate changes in TBI (p < 0.0001) but only LDL differed between S and SS (p < 0.02). Among septic patients, PCT levels declined significantly (p < 0.02) with time, followed by parallel decrease of HDL (p < 0.03) and increase of TG (p < 0.02) in the SS group. Neutrophil CD64 (nCD64) expression was higher in patients with SS (81.2%) and S (78.8%) as compared to those with TBI (5.5%) or C (0.9%, p < 0.0001). nCD64 was positively related with CRP, PCT, glucose, and TG (p < 0.01) and negatively with TC, LDL, and HDL (p < 0.0001), but not with severity of illness, hematologic indices, length of stay or mechanical ventilation duration.

Conclusions

In sepsis, the early stress-metabolic pattern is characterized by a high (nCD64, glucose, TG) - low (TC, HDL, LDL) combination in contrast to the moderate pattern of TBI in which only glucose increases combined with a moderate cholesterol - lipoprotein decrease. These early metabolic patterns persist the first 3 days of acute illness and are associated with the acute phase CD64 expression on neutrophils.

Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta-analysis

BACKGROUND

Procalcitonin is a promising marker for identification of bacterial infections. We assessed the accuracy and clinical value of procalcitonin for diagnosis of sepsis in critically ill patients.

METHODS

We searched Medline, Embase, ISI Web of Knowledge, the Cochrane Library, Scopus, BioMed Central, and Science Direct, from inception to Feb 21, 2012, and reference lists of identified primary studies. We included articles written in English, German, or French that investigated procalcitonin for differentiation of septic patients--those with sepsis, severe sepsis, or septic shock--from those with a systemic inflammatory response syndrome of non-infectious origin. Studies of healthy people, patients without probable infection, and children younger than 28 days were excluded. Two independent investigators extracted patient and study characteristics; discrepancies were resolved by consensus. We calculated individual and pooled sensitivities and specificities. We used I(2) to test heterogeneity and investigated the source of heterogeneity by metaregression.

FINDINGS

Our search returned 3487 reports, of which 30 fulfilled the inclusion criteria, accounting for 3244 patients. Bivariate analysis yielded a mean sensitivity of 0 · 77 (95% CI 0 · 72-0 · 81) and specificity of 0 · 79 (95% CI 0 · 74-0 · 84). The area under the receiver operating characteristic curve was 0 · 85 (95% CI 0 · 81-0 · 88). The studies had substantial heterogeneity (I(2)=96%, 95% CI 94-99). None of the subgroups investigated--population, admission category, assay used, severity of disease, and description and masking of the reference standard--could account for the heterogeneity.

INTERPRETATION

Procalcitonin is a helpful biomarker for early diagnosis of sepsis in critically ill patients. Nevertheless, the results of the test must be interpreted carefully in the context of medical history, physical examination, and microbiological assessment.

FUNDING

Ministry of Education and Research, the Deutsche Forschungsgemeinschaft, Thuringian Ministry for Education, Science and Culture, the Thuringian Foundation for Technology, Innovation and Research, and the German Sepsis Society.

Neutrophil CD64 expression as a biomarker in the early diagnosis of bacterial infection: a meta-analysis

BACKGROUND

Neutrophil CD64 expression is widely reported as an efficacious biomarker to differentiate infected patients from other non-infected patients. This meta-analysis was conducted to comprehensively and quantitatively summarize the accuracy of neutrophil CD64 in the early diagnosis of bacterial infection.

METHODS

A systematic review of related studies was conducted, and the sensitivity, specificity, and other data about the accuracy of CD64 expression on neutrophils were pooled using random effects models with 95% confidence intervals (CI) as the effect measurements. Summary receiver operating characteristic (SROC) curves and the Q* value were also calculated in the meta-analysis. Heterogeneity was tested, as well as the publication bias. Potential sources of heterogeneity were explored by assessing whether or not certain covariates significantly influenced the summary diagnostic odds ratio (SDOR).

RESULTS

A total of 26 studies including 3944 patients met the inclusion criteria for the final analysis. The summary estimate was 0.76 (95% CI 0.74-0.78) for sensitivity and 0.85 (95% CI 0.83-0.86) for specificity. The positive likelihood ratio (PLR), negative likelihood ratio (NLR), SDOR, and area under the SROC of neutrophil CD64 expression with Q* value were 6.67 (95% CI 4.67-9.53), 0.24 (95% CI 0.18-0.31), 34.29 (95% CI 19.59-60.01), and 0.92 (Q*=0.85), respectively. The pooled data from the included studies had high heterogeneity and the Egger test suggested a publication bias.

CONCLUSIONS

On the basis of our meta-analysis, neutrophil CD64 expression could be a promising and meaningful biomarker for diagnosing bacterial infection. Nevertheless, more large prospective studies should be carried out before the neutrophil CD64 test is used widely in the clinical setting because of the various cut-off values.

Antimicrobial drug-resistant microbes associated with hospitalized community-acquired and healthcare-associated pneumonia: a multi-center study in Taiwan

BACKGROUND/PURPOSE

Community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP) may be caused by potential antimicrobial drug-resistant (PADR) microbes. The aims of this study were to evaluate the incidences and risk factors associated with PADR microbes observed in patients with pneumonia occurring outside the hospital setting in Taiwan.

METHODS

We conducted a retrospective study of patients with CAP or HCAP admitted to six medical centers in the northern, central, and southern regions of Taiwan in 2007. The pathogens were evaluated by microbiological specimens within 72 hours after admission. The patients' comorbidities, pathogens, and outcomes were evaluated. The risk factors of PADR microbes were identified by logistic regression analysis.

RESULTS

The enrolled patients exhibited HCAP (n=713) and CAP (n=933). The pathogens associated with HCAP (n=383) and CAP (n=441) included Pseudomonas spp. (29%vs. 10%, p<0.001), Klebsiella spp. (24% vs. 25%, p=0.250), Escherichia coli (6% vs. 8%, p=0.369), Haemophilus influnezae (3% vs. 7%, p=0.041), Streptococcus pneumoniae (2% vs. 6%, p=0.003) and methicillin-resistant Staphylococcus aureus (MRSA) (8% vs. 4%, p=0.008). The core pathogens of CAP and HCAP differed among the three regions of Taiwan. PADR microbes, including Pseudomonas spp. (n=191), Acinetobacter spp. (n=41), MRSA (n=49) and cefotaxime- or ceftazidime-resistant Enterbacteriaceae (n=25), were isolated from 13% of patients with CAP and 23% of patients with HCAP. Previous hospitalization, and neoplastic and neurological diseases were significant risk factors for acquiring PADR microbes.

CONCLUSION

PADR microbes were common in patients with HCAP and CAP in Taiwan. Broad-spectrum antibiotics targeting PADR microbes should be administered to patients who have undergone previous hospitalization and who exhibit neurological disorders and/or malignancies.

The sensitivity of neutrophil CD64 expression as a biomarker of bacterial infection is low in critically ill patients

PURPOSE

CD64 expression on the surface of neutrophils has recently been proposed as an early marker of bacterial infection. The goal of this study was to determine whether the CD64 index allows differentiation of bacterial sepsis from viral and fungal sepsis and other inflammatory states in a critical-care setting.

METHODS

This was an observational prospective study conducted in a medical ICU of a university hospital. All patients admitted between September 2009 and March 2010 with at least two criteria for systemic inflammatory response syndrome (SIRS) were eligible for inclusion. Upon admission, hematological exams were conducted by flow cytometry, allowing quantification of CD64 expression (Leuko64™ kit, Trillium Diagnostics LLC, USA). ROC curve analysis was performed to evaluate the utility of the CD64 index in the diagnosis of bacterial infection. Patients with suspected infection were excluded when infection could not be microbiologically confirmed.

RESULTS

Our study included 293 patients with a SAPS II score of 45 (31-59). Bacterial infection was found in 148 patients and SIRS or non-bacterial infection was documented in 145 patients. A CD64 index greater than 2.2 predicted bacterial infection with a sensitivity and specificity of 63% (55-71%) and 89% (83-94%), respectively. The area under the ROC curve was 0.8 (0.75-0.84). Positive and negative likelihood ratios were 5.7 (5.0-6.5) and 0.4 (0.3-0.7), respectively.

CONCLUSIONS

The CD64 index is specific for bacterial infection among ICU patients. As a result of its weak sensitivity, the CD64 index may not be practically recommended, but it may be useful in combination with a more sensitive biological marker.