Innovative haematological parameters for early diagnosis of sepsis in adult patients admitted in intensive care unit

From reticulated platelets to immature platelet fraction: structure, function, and clinical applications

In comparison to mature platelets, reticulated platelets (RPs) are newly released from the bone marrow and exhibit a larger size, higher reactivity, and a greater quantity of RNA, and can be an agile indicator of platelet turnover. The transcriptome associated with platelet function is significantly upregulated in RPs, which is a possible explanation for RPs intrinsic hyper-reactivity. We presented a comprehensive overview of the detection techniques for RPs. Current methods to quantify RPs in clinical routine are flow cytometry and fully automated hematology analyzers (Sysmex-XE/XN, Abbott, ADVIA, Mindray), which make the detection of RPs simpler, faster and more affordable. The proportion of RPs increased in the circulation has potential diagnostic and prognostic values in multiple clinical settings (risk stratification in cardiovascular diseases, the effect on antiplatelet drugs, differential diagnosis of thrombocytopenia, monitor platelet recovery after bone marrow or stem cell transplantation, and other diseases). There have been several studies focusing on RPs in recent years, particularly in cardiovascular disease and thrombocytopenia. In this review we summarizes the current study with regard to RPs and discuss their likely contribution in clinical routine.

The potential role of leukocytes cell population data (CPD) for diagnosing sepsis in adult patients admitted to the intensive care unit

OBJECTIVES

The aim of the study was to evaluate the predictive value of cell population data (CPD) parameters in comparison with procalcitonin (PCT) and C-reactive protein (CRP) for an early diagnosis of sepsis in intensive care unit (ICU). The effect of renal function on CPD, PCT and CRP, in septic and non-septic patients was also investigated.

METHODS

This is a retrospective, observational and single-center study, performed with data collected from patients consecutively admitted to the ICU of the Edoardo Bassini Hospital in Milan. Patients were divided in septic and non-septic according to Sepsis-III criteria. The control group was formed by critically ill patients without sepsis. Patients with sepsis were further divided in patients with sepsis and patients with septic shock.

RESULTS

A significant difference between septic and non-septic patients was found for neutrophils complexity (NE-SSC), neutrophils fluorescence intensity (NE-SFL), width of dispersion of neutrophils fluorescence (NE-WY), monocytes complexity (MO-X), monocytes fluorescence intensity (MO-Y), PCT and CRP parameters. PCT, neutrophils sixe (NE-FSC), NE-WY, width of dispersion of neutrophils size (NE-WZ) and MO-X discriminated sepsis and septic-shock patients. CPD parameters were not influenced by renal function. CPD, PCT and CRP had a heterogeneous diagnostic performance efficiency in the prediction of sepsis. Overall, NE-SSC, NE-SFL, width of dispersion of neutrophils complexity (NE-WX), MO-X, MO-Y, PCT and CRP displayed the best diagnostic performance for sepsis.

CONCLUSIONS

This study suggested that some CPD parameters (i.e., NE-SFL and MO-X) might provide useful information for diagnosis and management of sepsis.

The Role of New Morphological Parameters Provided by the BC 6800 Plus Analyzer in the Early Diagnosis of Sepsis

BACKGROUND

Late diagnosis of sepsis is associated with adverse consequences and high mortality rate. The aim of this study was to evaluate the diagnostic value of hematologic research parameters, that reflect the cell morphology of blood cells, available on the BC 6800 plus automated analyzer (Mindray) for the early detection of sepsis.

MATERIALS AND METHODS

A complete blood count (CBC) was performed by Mindray BC 6800 Plus Analyzer in 327 patients (223 with a confirmed diagnosis of sepsis following sepsis-3 criteria, 104 without sepsis), admitted at the Intensive Care Unit of the Novara's Hospital (Italy) and in 56 patients with localized infection.

RESULTS

In univariate logistic regression, age, Hb, RDW, MO#, NMR, NeuX, NeuY, NeuZ, LymX, MonX, MonY, MonZ were associated with sepsis (p < 0.005). In multivariate analysis, only RDW, NeuX, NeuY, NeuZ, MonX and MonZ were found to be independent predictors of sepsis (p < 0.005). Morphological research parameters are confirmed to be predictors of sepsis even when analyzing the group with localized infection.

CONCLUSIONS

In addition to already established biomarkers and basic CBC parameters, new morphological cell parameters can be a valuable aid in the early diagnosis of sepsis at no additional cost.

The importance of morphological changes in neutrophils in the diagnosis of bacterial infections in dogs with confirmed urinary tract infections in a Veterinary Care Service, Rio de Janeiro, Brazil

Neutrophils (PMNs) are cellular markers used for diagnosing inflammation and/or infections. In this study, the objective was to highlight the importance of recording the toxic morphological alterations of the PMNs as markers of infection in 10 cases, positive bacterial isolation by culture due to dysuria, hematuria and/or fetid urine, as manifestations of urinary tract disease. Smear observations were performed by immersion for counting and morphological evaluations of 3,000 leukocytes in smears and in leukocyte concentrate. One (10.0%) of the dogs had leukocytosis, and two (20.0%) dogs had leukopenia. All animals showed toxic PMNs with positive bacterial culture. None of the cases in the study showed any quantitative alterations in PMNs such as: neutropenia or neutrophilia, where 100% had nuclear displacement of the regenerative type of PMNs to the left. 100% cases had toxic morphological changes: 90.0% had PMNs with toxic granulations, 80.0% had giant rod neutrophils, 70.0% had target PMNs, in 50.0% of those with vacuolation in the cytoplasm, in 40.0% of the animals, the presence of giant PMNs, 10.0% with Döhle bodies, and another animal 10.0% with karyorrhexis. All case studies had at least one association of two types of toxic changes. Toxic morphological alterations observed in PMNs through cystoscopy proved to be more reliable and sensitive in evidencing the diagnosis of infections than the quantitative alterations of absolute values of total leukocytes; therefore, they were essential in the laboratory diagnosis by blood count in the course of infections in dogs.

Usefulness of New Neutrophil-Related Hematologic Parameters in Patients with Myelodysplastic Syndrome

Myelodysplastic syndromes (MDS) are common malignant disorders with a poor prognosis. It is necessary to search for new rapid diagnostic methods to detect MDS patients with cytogenetic changes. The aim of the study was to assess new hematological neutrophil- and monocyte- related parameters I then bone marrow of MDS patient with and without cytogenetic changes. A total of 45 patients with MDS, including 17 patients with cytogenetic changes, were examined. The study was conducted using the Sysmex XN-Series hematological analyzer. New neutrophil and monocyte parameters, such as immature granulocytes (IG), neutrophil reactivity intensity (NEUT-RI), neutrophil granularity intensity (NEUT-GI), neutrophil size (NE-FSC) and neutrophil/monocyte data relating to granularity, activity and volume (NE-WX/MO-WX, NE-WY/MO-WY, NE-WZ/MO-WZ, MO-X, MO-Y, MO-Z) were evaluated. We observed higher median proportions of NE-WX, NE-WY, NE-WZ, and IG counts in MDS patients with cytogenetic changes than in patients without cytogenetic changes. The NE-FSC parameter was lower in MDS patients with cytogenetic changes than in patients without cytogenetic changes. The combination of new neutrophil parameters was found to be a new successful approach in distinguishing MDS patients with cytogenetic changes from patients without cytogenetic changes. It appears that there may be unique neutrophil parameter signatures associated with an underlying mutation.

Diagnostic performance of machine learning models using cell population data for the detection of sepsis: a comparative study

OBJECTIVES

To compare the artificial intelligence algorithms as powerful machine learning methods for evaluating patients with suspected sepsis using data from routinely available blood tests performed on arrival at the hospital. Results were compared with those obtained from the classical logistic regression method.

METHODS

The study group consisted of consecutive patients with fever and suspected infection admitted to the Emergency Department. The complete blood counts (CBC) were acquired using the Mindray BC-6800 Plus analyser (Mindray Diagnostics, Shenzhen, China). Cell Population Data (CPD) were also recorded. The ML and artificial intelligence (AI) models were developed; their performance was evaluated using several indicators, such as the area under the receiver operating curve (AUC), calibration plots and decision curve analysis (DCA).

RESULTS

Overall, all the tested approaches obtained an AUC>0.90. The logistic regression (LR) performed well compared to the ML/AI models. The naïve Bayes and the K-nearest neighbour (KNN) methods did not show good calibration properties. The multi-layer perceptron (MLP) model was the best in terms of discrimination, calibration and clinical usefulness.

CONCLUSIONS

The best performance in the early detection of sepsis was achieved using the ML and AI models. However, external validation studies are needed to strengthen model derivation and procedure updating.

Comparison of the value of immature retyculocyte and immature platelet in the diagnosıs of sepsis

BACKGROUND

Sepsis is one of the causes of pre-treatment morbidity and mortality in the pediatric age group. In the present study, we investigated the place of the immature granulocyte percentage, (IG) immature reticulocyte fraction (IRF), and immature platelet fraction (IPF) in the diagnosis of sepsis.

METHODS

Complete blood count, C-reactive protein, (CRP) procalcitonin (PCT) and blood cultures were measured in 125 critical patients who were followed-up in the intensive care unit with the suspicion of sepsis and 65 healthy children between 2017 and 2019. In addition to the complete blood counts and routine parameters, IG, IRF, and IPF were examined in the patients.

RESULTS

When the critical patient group and the healthy control group were compared, it was found that the total number of leukocytes (white blood cells), neutrophil count, platelet count, CRP, PCT, IG, IRF, and IPF values were higher at statistically significant levels. When septic and non-septic patients were compared, it was found that the CRP, PCT,IGP, and IPF were higher at statistically significant levels in the septic patients.

CONCLUSIONS

It was concluded that CRP, PCT, IG, and IPF were significant in determining sepsis and that PCT was the most sensitive and specific biomarker in these parameters. We believe that these parameters may be suitable for practical use in determining sepsis because they give faster results and suggest the diagnosis of sepsis.

Association of Transforming Growth Factor β1 Gene Polymorphisms and Inflammatory Factor Levels with Susceptibility to Sepsis

Objective: To study the association of transforming growth factor β1 (TGF-β1) gene single nucleotide polymorphisms (SNPs) and plasma TGF-β1 levels with susceptibility to sepsis. Methods: The genotypes of the TGF-β1 gene rs1800469, rs1800468, rs1800470, and rs1800471 loci in 285 sepsis patients (119 patients with severe sepsis and 166 patients with mild sepsis) and 285 healthy individuals (control group) were analyzed through Sanger sequencing. Enzyme-linked immunosorbent assay was used to detect the levels of plasma inflammatory factors. Results: The TGF-β1 gene SNP rs1800469 C allele was 0.56 times lower than the T allele in terms of risk of susceptibility to sepsis (95% confidence interval [CI]: 0.43-0.72, p < 0.01). Carriers of the A allele at the rs1800468 locus of the TGF-β1 were 2.82 times more susceptible to sepsis than those with the G allele (95% CI: 1.62-4.91, p < 0.01). The T allele at the rs1800470 locus of TGF-β1 produced a lower risk of sepsis than those with the C allele (odds ratio [OR] = 0.74, 95% CI: 0.57-0.94, p = 0.02). The risk of susceptibility to sepsis in the TGF-β1 rs1800471 locus G allele was 3.54 times higher than that of C allele (95% CI: 2.14-5.86, p < 0.01). The TGF-β1 gene rs1800469 T > C and rs1800470 C > T were associated with mild sepsis, whereas rs1800468 G > A and rs1800471 C > G were associated with severe sepsis (p < 0.01). The TGF-β1 gene rs1800469 T > C and rs1800470 C > T were associated with lower plasma TGF-β1 levels, whereas rs1800468 G > A and rs1800471 C > G were associated with higher TGF-β1 levels (p < 0.05). Conclusion: The alleles T > C of rs1800469 and C > T of rs1800470 of the TGF-β1 gene were associated with lower plasma TGF-β1 levels and a reduced risk of sepsis susceptibility, whereas the alleles rs1800468 G > A and rs1800471 C > G were associated with higher TGF-β1 levels and risk of susceptibility to sepsis.

Role of immature platelet fraction (IPF) in sepsis patients: A systematic review

Sepsis is extremely common amongst critically ill patients and requires early diagnosis. Hence, identifying a biomarker that could acknowledge sepsis at its prior stage is of vital significance. Immature platelets are a percentage of circulating platelets that contain RNA and is a newer parameter that is measured using automated hematology analyzers in diagnosing sepsis. This review article discusses 10 articles that reveal the role of immature platelet fraction in predicting the onset of sepsis and its relationship with mortality in sepsis. Literature search was done using PubMed, Scopus and Google Scholar and words like platelet indices and immature platelet fraction were typed in the search bar. The aim of this review article is to present a precise form of data that talk about immature platelet fraction (IPF) and its association with the severity and mortality of sepsis. Five out of 10 articles suggest that immature platelet fraction can predict the onset of sepsis and eight out of 10 articles suggest that increased IPF values are associated with high mortality.

Platelets parameters in septic shock: clinical usefulness and prognostic value

: Septic shock is a common cause of admission in the ICUs. Despite tremendous improvement in the management modalities, mortality remains high. Early diagnosis and prompt resuscitation are required to improve prognosis. Therefore, identifying a biomarker that could reveal the sepsis at its earlier stage is of paramount importance. In this regards, platelet parameters, such as mean platelet volume, immature platelet fraction and platelet-derived microparticles have been investigated as possible sepsis biomarkers. In fact, haemostasis disturbances are one of the hallmark of septic shock where platelets play a pivotal role in orchestrating the inflammatory response of the host. Moreover, these parameters could have a prognostic value as the severity of the multiorgan dysfunction is correlated with the inflammatory reaction.

Immature Platelet Dynamics in Immune-Mediated Thrombocytopenic States

A major challenge encountered by clinicians is differentiating presentations characterized by significant thrombocytopenia due to overlapping clinical symptoms and signs in the setting of ambiguous laboratory results. Immature platelets represent the youngest platelets that can be measured in peripheral blood by current hematology analyzers. These young platelets are larger, with higher RNA content recently released from the bone marrow. Thrombocytopenic presentations caused directly or indirectly by immune responses can lead to compensatory bone marrow responses seeking to normalize the platelet count; thus obtaining absolute immature platelet counts may be informative while triaging patients. Over the last decade, their use has expanded beyond being an early biomarker of bone marrow reconstitution post-hematopoietic stem cell transplantation to being used to establish bone marrow responses to infection and thrombocytopenias due to immune etiologies. Its accessibility as part of more detailed platelet indices obtained with routine laboratories makes it a promising option to understand the bone marrow's real-time response to disease states characterized by thrombocytopenia. This review will look at the immature platelet count as a biomarker, while presenting current attempts trying to understand how it could be used in thrombocytopenias occurring secondary to a given immune etiology.

Evaluation of Immature Platelet Fraction in Lower Respiratory Tract Infections: A Retrospective Study

Introduction

Immature platelet fraction (IPF) is a parameter of an automated hematologic analyzer and is related to platelet size and cytoplasmic RNA content. It reflects thrombopoiesis and is often used as the marker of platelet activity. IPF has been evaluated mostly in hematologic disorders and has also been evaluated in patients with gestational hypertension, sepsis, autoimmune diseases and in hospitalised patients with neutrophilia. Platelets, asides from the maintenance of hemostasis, release inflammatory mediators that can modify leukocyte and endothelial responses to various inflammatory stimuli. Lower respiratory tract infections are the leading cause of death from infections worldwide. The role of platelets in lower respiratory tract infections has been reported in many studies. IPF, which is related to platelet activation, has not been evaluated in patients with lower respiratory tract infections.

Methods

The study involved patients who fulfilled the criteria of community-acquired pneumonia (CAP) and aspiration pneumonia (AP). In addition, age and sex-matched healthy controls were involved. Whole blood samples were collected from healthy controls and from the patients on admission. The mean IPF% and C-reactive protein (CRP) levels were measured in patients with CAP, in patients with AP and in healthy controls. The mean IPF% values in patients with infection were compared to mean IPF% values in healthy controls. The mean IPF% values were compared to mean CRP levels in patients with infection. Additionally, the mean IPF% values in patients that died in the first 14 days were compared to the mean IPF% values in patients that were alive. The statistical analysis of data was performed with the Statistical Package for the Social Sciences (SPSS) for Windows, Version 13.0 (SPSS Inc, Chicago, IL). 

Results

The study population consisted of 45 patients (27 patients with CAP and 18 patients with AP), 27 males and 18 females, with a mean age of 72.11 ± 16.4 years and 39 healthy controls, 22 males and 17 females with a mean age of 64.2 ± 14.8 years. The mean CRP levels in patients with infection were 155.2±119.1 mg/dl. The mean IPF% value of patients with infection was 2.76 ± 2.27 and the mean IPF% value of controls was 1.72 ± 0.77 (p < 0.006). The IPF% value in patients with CAP was 2.55 ± 2.02 and in patients with AP 3.07 ± 2.64 (p = 0.595). The mean IPF% value in patients with infection had no linear correlation with CRP value in these patients (r = 0.076, p = 0.62). The mean IPF% value in all patients that died in the first 14 days was 3.75 ± 2.44 and the mean IPF% value in all patients alive was 2.35 ± 2.11 (p = 0.06). The mean IPF% value in patients with CAP who died in the first 14 days of hospitalisation was 5.54 ± 3.17 and in patients with CAP who were alive was 1.87 ± 0.72 (p = 0.06). The mean IPF% value in patients with AP who died was 2.63 ± 0.85 and in patients with AP who were alive was 3.41 ± 3.51 (p = 0.554).

Conclusions

Mean IPF% value is greater in patients with lower respiratory tract infections, including CAP and AP, compared to healthy controls. There is no linear correlation between IPF values and CRP values in patients with lower respiratory tract infections. In addition, there is a difference in mean IPF% value between patients who died in the first 14 days of hospitalisation compared to those who were alive, but not statistically significant.

Multicenter evaluation of analytical performances of platelet counts and platelet parameters: Carryover, precision, and stability

INTRODUCTION

The correctness of the results of automated platelet analysis is still highly debated. The aim of this multicenter study, conducted according to international guidelines, was to verify the analytical performance of nine different types of hematology analyzers (HAs) in the automated platelet analysis.

METHODS

Four hundred eighty-six peripheral blood samples (PB), collected in K₃ EDTA tubes, were analyzed by ABX Pentra, ADVIA2120i, BC-6800, BC-6800 Plus, Cell-DYN Sapphire, DxH800, XE-2100, XE-5000, XN-20 with PLT-F App. Within-run imprecision and between-run imprecision were carried out using PB and material control, respectively. The carryover, low limit of quantification (LoQ), and the PB stability were evaluated.

RESULTS

The carryover was absent for all HAs. The LoQ of PLT ranged between 2.0 (Cell-Dyn Sapphire) and 25.0 × 10⁹ /L (ADVIA 2120i), while immature platelet fraction (IPF) ranged between 1.0 (XN-20) and 12.0 × 10⁹ /L (XE-5000). The imprecision (%CV) increases as the platelet count decreases. No HAs showed desirable CV_APS for PLT counts less than 50.0 × 10⁹ /L, with the exception of Cell-DYN Sapphire (CV 3.0% with PLT-O mean value of 26.7 × 10⁹ /L), XN-20 (CV 2.4% with PLT-F mean value of 21.5 × 10⁹ /L), and BC-6800 Plus (CV 1.9% with PLT-O mean value of 26.5 × 10⁹ /L). The sample stability ranged between under two hours for MPV by ADVIA2120i and 8 hours for other PLT parameters and HAs.

CONCLUSION

The findings of this study may provide useful information regarding carryover, precision, and stability of platelet counts and parameters, especially in thrombocytopenic samples. Moreover, the stability of sample for platelet analysis is conditioned by the HA and by temperature and storage time.

Reticulated platelets – clinical application and future perspectives

Reticulated platelets are immature platelets freshly released from the bone marrow into the circulation and contain vestigial amounts of ribonucleic acid. Thus, they can serve as an indicator for the activity of thrombopoiesis. Despite the current lack of a standardized reference method, two types of hematology analyzers have incorporated a fully automated measurement of reticulated platelets. The “immature platelet fraction” (IPF; Sysmex XE-/XN-series) has some clinical utility in the differential diagnosis of thrombocytopenia. This is less clear for “reticulated platelets” (retPLT; Abbott CELL-DYN Sapphire/Alinity HQ). The usefulness of these parameters in the prediction of platelet recovery after chemotherapy or stem cell transplantation and as a decision aid for platelet transfusions has not been unequivocally confirmed. Recent findings have shown an association of reticulated platelets with an adverse risk in patients with coronary artery disease and stroke as well as resistance to anti-platelet therapy. Furthermore, a role of reticulated platelets for the prediction of sepsis was indicated. However, validation in larger prospective trials is necessary to establish the clinical benefit of reticulated platelets in these conditions. This review gives an overview of the available analytical methods and summarizes the current knowledge regarding the clinical application of reticulated platelets.