Platelet related gene IQGAP1 contributes to the onset and abnormal immune landscape of ischemic stroke patients

INTRODUCTION

Ischemic stroke (IS) is a complex illness resulting from a combination of numerous environmental and genetic risk factors. Recent reports have shed light on the vital role that platelets play in the pathophysiology of IS. Here, we aimed to explore the potential platelet-related genes in IS and investigate the effect of platelet-related genes in the immune microenvironment of IS.

METHODS

The data of IS were retrieved from the Gene Expression Omnibus database. Firstly, we screened the platelet-related genes that were correlated with the onset of IS using differential expression analysis, enrichment analyses, and protein-protein interaction (PPI) network. Moreover, we analyzed the clinical value and functional information of platelet-related genes in IS. Finally, we explored the correlation between platelet-related genes and immune cells' infiltration.

RESULTS

Ten platelet-related genes that were correlated with the onset of IS were identified, among which IQGAP1 was located at the core of the PPI network. IQGAP1 was found to be expressed in the normal brain tissue and its expression was significantly elevated in IS samples. The area under the curve (AUC) values for IQGAP1 in both the GSE16561 and GSE58294 datasets were close to 1. IQGAP1 knockdown might increase OGD/R‑induced HT22 cell viability. Additionally, FoxO signaling pathway, NOD-like receptor signaling pathway, Phagosome and Platelet activation pathways were significantly activated in IS patients with high IQGAP1 expression compared to those with low IQGAP1 expression. The IS patients in the IQGAP1high and IQGAP1low groups showed dramatically different proportions of immune cells and immune-related functions, and the IQGAP1 expression was correlated with the immune cell' infiltration in IS.

CONCLUSIONS

In this study, we identified the IQGAP1 might serve as a potential diagnostic marker for IS, and the IQGAP1 expression was very relevant in determining the immune cell' infiltration in IS patients.

Red cell distribution width as a cardiovascular risk predictor in adults with hypertension in sub-Saharan Africa

Red cell distribution width (RDW) quantifies the degree of variation in erythrocyte size, is identified as a potential marker of adverse cardiovascular events, and may be a surrogate marker for assessing cardiovascular disease (CVD) risk in low-resource settings. We evaluated RDW as a predictor of CVD risk compared to the World Health Organization (WHO) CVD risk score among adults with hypertension attending primary healthcare centers (PHCs) in Ghana and Nigeria. Adults with hypertension attending selected PHCs in Ghana and Nigeria participated in a cross-sectional study. Each participant underwent blood pressure (BP) measurement and laboratory evaluation (RDW, total cholesterol, and fasting blood sugar) following standard methods. We recruited 319 adults aged 40-74 years from the study sites. The mean (standard deviation) RDW was 13.96 (1.1%). The median CVD risk score was 8.11% [interquartile range (IQR) 4.00 to 11.00]. For participants with hemoglobin (Hb) levels ≥ 12 g/dL, RDW showed positive correlations with age (r = 0.136; p = 0.042); systolic BP (r = 0.183; p = 0.006), diastolic BP (r = 0.206, p = 0.002) and WHO CVD risk scores (r = 0.166, p = 0.013). Multiple linear regression showed an independent association between RDW and WHO CVD risk scores with an upward gradient, and was most significant at 3rd quartiles. Using receiver operating characteristic curve, the C-statistic was 0.673 (95% confidence interval: 0.618 to 0.724), p = 0.031. With a cut-off of >14, the RDW demonstrated a sensitivity of 81.82% and specificity of 55.84%. This study shows that at Hb levels ≥ 12 g/dL, RDW modestly predicted CVD risk in adults with hypertension in sub-Saharan Africa.

Haematological Indices in Acute Coronary Syndrome Patients in Ethiopia: A Comparative Cross-Sectional Study

Background

Numerous biomarkers are used as diagnostic, prognostic, and predictive indicators of myocardial ischemia. The most commonly used biomarkers are cardiac troponin I (Tn-I) and creatinine kinase (CK-MB). However, in developing nations, their availability in primary care settings is extremely limited. In such situations, easily available assays such as complete blood count (CBC) should be investigated as prognostic indicators in individuals with acute coronary syndrome (ACS).

Objective

This study aimed to compare the pattern of haematological indices and blood cell ratios of ACS patients compared with apparently healthy controls.

Methods

Patients diagnosed with ACS were recruited consecutively between 01 May 2022 and 31 October 2023 at Jimma Medical Center (JMC). Biochemical analyses and complete blood counts were performed. Analysis of variance was performed to compare the continuous variables. Spearman correlation coefficient tests were performed to correlate hematologic parameters with high sensitive troponin-I (hs-Tn-I) levels.

Results

This study enrolled 220 participants (110 patients with ACS and age, sex, and place of residence matched 110 non-ACS controls). From ACS group 99 (90%) were diagnosed with ST-elevated myocardial infarction. The ACS group had a significantly greater mean platelet volume (MPV), white blood cell count, red cell distribution width (RDW), neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio. The RDW (r = 0.248, p = 0.009) and MPV (r = 0.245, p = 0.009) were significantly positively correlated with hs-Tn-I levels in the ACS group. MPV, RDW, and monocyte count were significantly higher in non-survivor ACS patients (p <0.05).

Conclusion

The significant differences observed in haematological parameters between individuals with ACS and healthy controls suggest the potential utility of these easily accessible and cost-effective diagnostics in predicting future morbidity and ACS risk. Incorporating these routine evaluations into clinical practice could enhance risk assessment and improve patient outcomes.

Association between red blood cell distribution width and all-cause mortality of patients after intra-aortic balloon pump in the intensive care unit

Objectives

This study aimed to explore the relationship between red blood cell distribution width (RDW) and all-cause mortality in critically ill patients undergoing intra-aortic balloon pumping (IABP) in the intensive care unit (ICU).

Methods

This study retrospectively analyzed data from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. The primary endpoint was the 30-day mortality rate, while the secondary endpoint was the in-hospital mortality rate. Restricted cubic splines were used to assess the dose-response relationship. The receiver operating characteristic (ROC) curve and Kaplan-Meier curve analysis were carried out to evaluate the predictive performance of RDW. Moreover, multiple logistic regression analyses and subgroup analyses were conducted to investigate the relationship between RDW and 30-day mortality. Finally, propensity score matching (PSM) was performed to adjust for the imbalance of covariates.

Results

In total, 732 patients were finally identified from the MIMIC-IV database in this study. The RDW of patients in the non-survivor group was significantly higher compared with those in the survivor group (P < 0.01). Multiple logistic regression analyses corroborated RDW was an independent predictor of all-cause 30-day mortality in critically ill patients post-IABP. Meanwhile, ROC analysis identified an RDW cutoff of 14.2%. High RDW patients exhibited a 131% (OR = 2.31, 95% CI: 1.49-3.61) elevated risk of 30-day mortality after adjusting for confounders in multivariable logistic regression. After PSM, 412 patients were included in the matched cohort. In the original and matched cohorts, the high RDW group had higher 30-day and in-hospital mortality rates, as well as longer ICU stays. Lastly, the area under the ROC curve for 30-day mortality was 0.686, with an optimal cutoff point of 14.2 for RDW (sensitivity: 69.09 % and specificity: 63.32%).

Conclusion

RDW could be a simple and valuable prognostic tool to predict mortality in critically ill patients after IABP.

Association of red blood cell distribution width with hospital admission and in-hospital mortality across all-cause adult emergency department visits

Objectives

To test the association between the initial red blood cell distribution width (RDW) value in the emergency department (ED) and hospital admission and, among those admitted, in-hospital mortality.

Materials and Methods

We perform a retrospective analysis of 210 930 adult ED visits with complete blood count results from March 2013 to February 2022. Primary outcomes were hospital admission and in-hospital mortality. Variables for each visit included demographics, comorbidities, vital signs, basic metabolic panel, complete blood count, and final diagnosis. The association of each outcome with the initial RDW value was calculated across 3 age groups (<45, 45-65, and >65) as well as across 374 diagnosis categories. Logistic regression (LR) and XGBoost models using all variables excluding final diagnoses were built to test whether RDW was a highly weighted and informative predictor for each outcome. Finally, simplified models using only age, sex, and vital signs were built to test whether RDW had additive predictive value.

Results

Compared to that of discharged visits (mean [SD]: 13.8 [2.03]), RDW was significantly elevated in visits that resulted in admission (15.1 [2.72]) and, among admissions, those resulting in intensive care unit stay (15.3 [2.88]) and/or death (16.8 [3.25]). This relationship held across age groups as well as across various diagnosis categories. An RDW >16 achieved 90% specificity for hospital admission, while an RDW >18.5 achieved 90% specificity for in-hospital mortality. LR achieved a test area under the curve (AUC) of 0.77 (95% confidence interval [CI] 0.77-0.78) for hospital admission and 0.85 (95% CI 0.81-0.88) for in-hospital mortality, while XGBoost achieved a test AUC of 0.90 (95% CI 0.89-0.90) for hospital admission and 0.96 (95% CI 0.94-0.97) for in-hospital mortality. RDW had high scaled weights and information gain for both outcomes and had additive value in simplified models predicting hospital admission.

Discussion

Elevated RDW, previously associated with mortality in myocardial infarction, pulmonary embolism, heart failure, sepsis, and COVID-19, is associated with hospital admission and in-hospital mortality across all-cause adult ED visits. Used alone, elevated RDW may be a specific, but not sensitive, test for both outcomes, with multivariate LR and XGBoost models showing significantly improved test characteristics.

Conclusions

RDW, a component of the complete blood count panel routinely ordered as the initial workup for the undifferentiated patient, may be a generalizable biomarker for acuity in the ED.

Red Cell Distribution Width/Albumin Ratio: A Predictor of In-Hospital All-Cause Mortality in Patients with Acute Myocardial Infarction in the ICU

Purpose

Red cell distribution width (RDW) and albumin level are linked to adverse outcomes in patients with acute myocardial infarction (AMI). Nonetheless, it remains unknown whether the RDW/albumin ratio (RAR) is associated with the short-term prognosis of AMI. Using a large cohort, we aimed to explore the association between RAR and in-hospital all-cause mortality in intensive care unit (ICU) patients with AMI.

Patients and Methods

The patients' data analyzed in this retrospective cohort investigation were obtained from the eICU Collaborative Research Data Resource. RAR was calculated based on the serum albumin level and RDW. The primary outcome was in-hospital all-cause mortality. Receiver operating characteristic curve, multiple logistic regression model, and Kaplan-Meier survival analysis were performed to explore the prognostic value of RAR.

Results

We enrolled 2594 patients in this study. After correcting for confounding factors, the RAR was an independent predictor for in-hospital mortality in our model (odds ratio [OR] 1.27, 95% confidence interval [CI] 1.12, 1.43). A similar relationship was observed with mechanical ventilation use. RAR showed a better predictive value with an area under the curve (AUC) of 0.738 (cutoff, 4.776) for in-hospital all-cause mortality compared to RDW or albumin alone. Kaplan-Meier estimator curve analyses for RAR demonstrated that the group with RAR ≥4.776%/g/dL had poorer survival than the group with RAR <4.776%/g/dL (p< 0.0001). The subgroup analysis revealed no significant interaction between RAR and in-hospital all-cause mortality in all strata.

Conclusion

RAR was an independent risk factor for in-hospital all-cause mortality in ICU patients with AMI. Higher RAR values corresponded to higher mortality rates. RAR is a more accurate predictor of in-hospital all-cause mortality in patients with AMI in the ICU than albumin or RDW. Thus, RAR may be a potential biomarker of AMI.

The role of red blood cell distribution width in predicting coronary artery lesions in pediatric patients with kawasaki disease

Background

Recent studies have shown that red blood cell distribution width (RDW) has emerged as a novel predictor of cardiovascular diseases. We aim to investigate the association between RDW and the risk of coronary artery lesions (CALs) in pediatric patients with Kawasaki disease (KD).

Methods

KD patients were classified as the CALs group (patients with CALs) and non-CALs group (patients without CALs). Differences among the groups were analyzed by Mann-Whitney U-test and Chi-square analysis. The independent risk factors of CALs were identified by multivariate logistic regression analysis, followed by receiver operating characteristic (ROC) curve analysis to calculate the optimal cut-off value.

Results

The red blood cell distribution width (RDW) and C-reactive protein were significantly higher in the CALs group than those in the non-CALs group (p < 0.01). Multivariate logistic regression analysis revealed that RDW (OR = 5.2, 95% CI, 4.064 to 6.654) was independent risk factors of CALs in KD patients (p < 0.01). The subgroup analysis also confirmed that the high level of RDW was an independent risk factor for the development of CALs in patients with complete and incomplete KD. The ROC analysis showed the optimal cut-off value of RDW for predicting CALs was >13.86%, with a sensitivity of 75.79% and specificity of 92.81% (AUC = 0.869, 95% CI = 0.844-0.892; p < 0.0001).

Conclusions

RDW is an independent predictor with high sensitivity and specificity to predict CALs in KD patients. The elevation in RDW level (>13.86%) may be used as novel biomarkers for early predicting CALs in KD patients during the acute phase.

Red Blood Cell Distribution Width as Novel Biomarker in Cardiovascular Diseases: A Literature Review

Red blood cell distribution width (RDW) is a measure of the change in size of red blood cells and it is used in combination with other hematological parameters for the differential diagnosis of anemias. Recent evidence suggested that the change in RDW level may be a predictive biomarker of morbidity and mortality in cardiovascular diseases (CVDs). Cardiovascular diseases are the most common cause of death globally as compared to cancer and communicable diseases. Early diagnosis and prompt intervention of these diseases are very important to minimize their complications. Nowadays, the diagnosis of most cardiovascular diseases majorly depends on clinical judgment, electrocardiography and biochemical parameters. Red blood cell distribution width as a new predictive biomarker may play a pivotal role in assessing the severity and progression of CVDs. However, the underlying mechanisms for the association between RDW and CVDs are not clear. A deeper understanding of their association could help the physicians in more careful identification, early prevention, intervention, and treatment to prevent adverse cardiovascular events. This review aims to elaborate on the recent knowledge on the association between RDW and cardiovascular diseases and some possible pathophysiological mechanisms.

Thrombo-Inflammation and Immunological Response in Ischemic Stroke: Focusing on Platelet-Tregs Interaction

Strokes are mainly caused by thromboembolic obstruction of a major cerebral artery. Major clinical manifestations include paralysis hemiplegia, aphasia, memory, and learning disorders. In the case of ischemic stroke (IS), hyperactive platelets contribute to advancing an acute thrombotic event progression. Therefore, the principal goal of treatment is to recanalize the occluded vessel and restore cerebral blood flow by thrombolysis or mechanical thrombectomy. However, antiplatelets or thrombolytic therapy may increase the risk of bleeding. Beyond the involvement in thrombosis, platelets also contribute to the inflammatory process induced by cerebral ischemia. Platelet-mediated thrombosis and inflammation in IS lie primarily in the interaction of platelet receptors with endothelial cells and immune cells, including T-cells, monocytes/macrophages, and neutrophils. Following revascularization, intervention with conventional antiplatelet medicines such as aspirin or clopidogrel does not substantially diminish infarct development, most likely due to the limited effects on the thrombo-inflammation process. Emerging evidence has shown that T cells, especially regulatory T cells (Tregs), maintain immune homeostasis and suppress immune responses, playing a critical immunomodulatory role in ischemia-reperfusion injury. Hence, considering the deleterious effects of inflammatory and immune responses, there is an urgent need for more targeted agents to limit the thrombotic-inflammatory activity of platelets and minimize the risk of a cerebral hemorrhage. This review highlights the involvement of platelets in neuroinflammation and the evolving role of Tregs and platelets in IS. In response to all issues, preclinical and clinical strategies should generate more viable therapeutics for preventing and managing IS with immunotherapy targeting platelets and Tregs.

Accuracy of neutrophil to lymphocyte and monocyte to lymphocyte ratios as new inflammatory markers in acute coronary syndrome

Background

Inflammation plays a key role in the development of atherosclerosis and in the pathogenesis of acute coronary syndrome (ACS). Leukocytes and leukocytes ratios were recognized as inflammatory markers in predicting the presence and severity of ACS.

Methods

This study aimed to investigate the diagnostic accuracy of neutrophil to lymphocyte ratio (NLR) and monocyte to lymphocyte ratio (MLR) with ACS. One hundred patients admitted to the Cardiac Center who were confirmed to have ACS and 100 healthy controls confirmed not to have ACS were enrolled in this study. ECG and troponin I test were used as gold standards to make sure that the participants with or without ACS. Total white blood cells (WBCs) count, NLR, and MLR values were estimated.

Results

Total WBCs, neutrophil, and monocyte counts were significantly higher while lymphocyte counts were significantly lower in ACS patients than in the healthy controls (p < 0.001). NLR and MLR were significantly higher in ACS patients than in the healthy controls (p < 0.001). Among all the studied markers, NLR was found to be the strongest predictive marker of ACS (OR: 3.3, p < 0.001), whereas MLR was non-significant (p > 0.05). A cut-off value of 2.9 of NLR had 90% sensitivity and 88% specificity while 0.375 cut-off value of MLR had 79% sensitivity, 91% specificity for predicting ACS presence.

Conclusions

NLR is a simple, widely available, and inexpensive inflammatory marker which can be an auxiliary biomarker in the diagnosis of ACS with a cut-off value of 2.9 in our population.

Haematologic indices in hepatitis B virus-related liver disease

Several markers and prognostic scores have been identified for predicting the development and progression of liver disease; among them, haematological parameters (the neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR), platelet to lymphocyte ratio (PLR), red cell distribution width (RDW), RDW to platelet ratio (RPR), mean platelet volume (MPV), and mean corpuscular volume (MCV)) have recently gained significant interest. Compared with traditional prognostic factors, haematological indices are easy to obtain and relatively inexpensive. There is growing evidence that these haematological indices play a key role in HBV-related liver diseases and has been proposed as a predictive marker of adverse outcomes in these patients. This article focuses on discussing the diagnostic and prognostic value of the haematological indices in patients with HBV-related liver diseases.

The role of red blood cell distribution width (RDW) in cardiovascular risk assessment: useful or hype?

Red blood cell distribution width (RDW) reflects erythrocyte size distribution, thus representing a reliable index of anisocytosis, widely used for the differential diagnosis of micro- and normocytic anaemias. Along with the large use in diagnostic hematology, RDW has been associated with presence and complications of a vast array of human pathologies during the last decades, including cardiovascular (CV) diseases. This article is hence aimed to provide an overview of important studies and systematic reviews with meta-analysis, in which RDW has been associated with CV events and mortality, in the attempt of establishing whether enough evidence exists for supporting its routine use in clinical practice. According to available data it seems reasonable to conclude that although the diagnostic specificity is low, and this measure is still plagued by important lack of standardization, RDW can be regarded as an index of enhanced patient fragility and higher vulnerability to adverse outcomes. Abnormal RDW values shall hence persuade physicians to broaden the diagnostic reasoning over anaemias, especially those due to malnutrition or malabsorption, encompassing a comprehensive assessment of traditional and non-traditional CV risk factors.

Association of red blood cell distribution width with severity of hepatitis B virus-related liver diseases

BACKGROUND

Red blood cell distribution width (RDW) has been indicated to be an inflammatory indicator in a variety of diseases. However, no consistent conclusions regarding it's relevance to hepatitis B virus (HBV) -related liver diseases have been made. This meta-analysis was conducted to assess the significance of RDW in HBV-related liver diseases.

METHODS

A comprehensive literature review was conducted using PubMed, Embase, and China National Knowledge Infrastructure (CNKI) through August 20, 2017 to identify studies that reported the association between RDW and HBV-related liver diseases. The standard mean difference (SMD) and corresponding 95% confidence interval (CI) were used to assess the associations.

RESULTS

Twenty-four studies met the eligibility criteria were included in the meta-analysis. These studies included 3272 HBV-infected patients and 2209 healthy controls. Chronic hepatitis B (CHB) patients had significantly increased RDW levels compared with healthy controls (SMD =1.399, 95% CI 0.971-1.827, p < 0.001]. Moreover, acute on chronic liver failure (ACLF) patients (SMD = 1.309, 95% CI 0.775-1.843, p < 0.001) and cirrhotic patients (SMD = 0.948, 95% CI 0.715-1.180, p < 0.001) had significantly elevated RDW levels compared with CHB patients. However, no statistical significance was obtained in RDW levels between cirrhosis and ACLF (SMD = 0.167, 95% CI -0.382 -0.716, p = 0.051).

CONCLUSION

RDW values were elevated in HBV-related liver diseases and correlated with the disease severity, suggesting that RDW levels may differentiate CHB from healthy controls and ACLF and cirrhosis from CHB but they appear to have no distinguishing characteristic between ACLF and cirrhosis.

Elements of the complete blood count associated with cardiovascular disease incidence: Findings from the EPIC-NL cohort study

All blood cells (white blood cells [WBC], red blood cells [RBC] and platelets) can play a role in atherosclerosis. Complete blood count (CBC) is widely available in clinical practice but utility as potential risk factors for cardiovascular disease (CVD) is uncertain. Our aim was to assess the associations of pre-diagnostic CBC with incidence of CVD in 14,362 adults free of CVD and aged 47.8 (±11.7) years at baseline, followed-up for 11.4 years (992 incident cases). Cox proportional hazards regressions were used to estimate HRs and 95%CI. Comparing the top (T3) to bottom (T1) tertile, increased total WBC, lymphocyte, monocyte and neutrophil counts were associated with higher CVD risk: 1.31 (1.10; 1.55), 1.20 (1.02; 1.41), 1.21 (1.03; 1.41) and 1.24 (1.05; 1.47), as well as mean corpuscular volume (MCV: 1.23 [1.04; 1.46]) and red cell distribution width (RDW: 1.22 [1.03; 1.44]). Platelets displayed an association for count values above the clinically normal range: 1.49 (1.00; 2.22). To conclude, total and differential WBC count, MCV, RDW and platelet count likely play a role in the aetiology of CVD but only WBC provide a modest improvement for the prediction of 10-year CVD risk over traditional CVD risk factors in a general population.

Relationship between High Red Cell Distribution Width and Systemic Inflammatory Response Syndrome after Extracorporeal Circulation

OBJECTIVE

Cardiac surgical operations involving extracorporeal circulation may develop severe inflammatory response. This severe inflammatory response syndrome (SIRS) is usually associated with poor outcome with no predictive marker. Red cell distribution width (RDW) is a routine hematological marker with a role in inflammation. We aim to determine the relationship between RDW and SIRS through our study.

METHODS

A total of 1250 patients who underwent cardiac surgery with extracorporeal circulation were retrospectively analyzed out of which 26 fell into the SIRS criteria and 26 consecutive control patients were taken. RDW, preoperative clinical data, operative time and postoperative data were compared between SIRS and control groups.

RESULTS

The demographic profile of the patients was similar. RDW was significantly higher in the SIRS versus control group (15.5±2.0 vs. 13.03±1.90), respectively with P value <0.0001. There was significant mortality in the SIRS group, 20 (76.92%) as compared to 2 (7.6%) in control group with a P value of <0.005. Multiple logistic regression analysis revealed that there was significant association with high RDW and development of SIRS after extracorporeal circulation (OR for RDW levels exceeding 13.5%; 95% CI 1.0-1.2; P<0.05).

CONCLUSION

Increased RDW was significantly associated with increased risk of SIRS after extracorporeal circulation. Thus, RDW can act as a useful tool to predict SIRS in patients undergoing cardiac surgery with extracorporeal circulation. Hence, more aggressive measures can be taken in patients with high RDW to prevent postoperative morbidity and mortality.

Association of erythrocyte deformability with red blood cell distribution width in metabolic diseases and thalassemia trait

Increased red blood distribution width (RDW) in anemia is related to disturbances in the cellular surface/volume ratio, usually accompanied by morphological alterations, while it has been shown in inflammatory diseases that the activity of pro-inflammatory cytokines disturbing erythropoiesis increases RDW. Recently it has been reported that higher RDW is related with decreased erythrocyte deformability, and that it could be related with the association of RDW and increased risk of cardiovascular diseases. In order to analyze the influence of morphological alterations and proinflammatory status on the relationship between RDW and erythrocyte deformability, we analyzed erythrocyte deformability along with RDW and other hematological and biochemical parameters in 36 α-thalassemia, 20 β-thalassemia, 20 δβ-thalassemia trait carriers, 61 metabolic syndrome patients and 76 morbidly obese patients. RDW correlated inversely with erythrocyte deformability in minor β-thalassemia (r =-0.530, p <  0.05), and directly in both metabolic syndrome and morbidly obese patients (ρ= 0.270, p <  0.05 and ρ= 0.258, p <  0.05, respectively). Minor β-thalassemia is often accompanied by more marked cell-shaped perturbations than other thalassemia traits. This could be the reason for this negative association only in this setting. Higher anisocytosis seems to be associated with greater morphologic alterations (shape/volume), which reduce erythrocyte deformability. The proinflammatory profile in metabolic patients can be related to the positive association of RDW with erythrocyte deformability found in these patients. However, further research is needed to explain the mechanisms underlying this association.

Red blood cell distribution width and cardiovascular diseases

BACKGROUND

The red blood cell distribution width (RDW) is a rather simple measure of red blood cell (RBC) size heterogeneity (i.e., anisocytosis), which is easily calculated by dividing the standard deviation (SD) of erythrocyte volumes for the mean corpuscular volume (MCV). Emerging evidence suggests that, besides RBC abnormalities, many human disorders may be frequently associated with a high degree of anisocytosis.

METHODS

In this narrative review, we analyzed the current scientific literature about the putative role and the potential epidemiologic association between RDW and cardiovascular diseases. The findings of the most representative epidemiological studies were summarized and discussed.

RESULTS

Overall, considerable and convincing evidence has been brought that an increased RDW value is associated with acute coronary syndrome (ACS) [including acute myocardial infarction (AMI)], ischemic cerebrovascular disease (including stroke), peripheral artery disease (PAD), as well as with atrial fibrillation (AF), heart failure (HF) and hypertension. Higher anisocytosis also significantly and independently predicts adverse outcomes in patients with these conditions.

CONCLUSIONS

Although the role of anisocytosis in the pathogenesis of cardiovascular diseases remains uncertain, the considerable evidence available so far suggests that the clinical use of RDW may be broadened beyond the conventional boundaries of erythrocyte disorders, in particular for assisting the diagnosis and prognostication of patients with ACS, ischemic cerebrovascular disease, PAD, HF and AF.

Red blood cell distribution width is associated with myocardial injury in non-ST-elevation acute coronary syndrome

OBJECTIVES

The red blood cell distribution width has been associated with an increased risk of cardiovascular events. In the present study, we assessed the relationship between red cell distribution width values and cardiac troponin I levels in patients admitted with non-ST-elevation acute coronary syndrome.

METHODS

We analyzed blood parameters in 251 adult patients who were consecutively admitted to the intensive coronary care unit with non-ST-elevation acute coronary syndrome over a 1-year period. For all patients, a baseline blood sample was collected for routine hematological testing. Cardiac troponin I was measured at baseline and after 6 h. The patients were diagnosed with non-ST-elevation myocardial infarction or unstable angina based on the elevation of cardiac troponin I levels.

RESULTS

The red cell distribution width was higher in the group with non-ST-elevation myocardial infarction compared with the patient group with unstable angina (14.6±1.0 vs 13.06±1.7, respectively; p = 0.006). Coronary thrombus was detected more frequently in the group of patients with non-ST-elevation myocardial infarction than in the patients with unstable angina (72% vs 51%, respectively; p = 0.007). Using receiver operating characteristic curve analysis for the prediction of non-ST-elevation myocardial infarction based on the red cell distribution width, the area under the curve was 0.649 (95% confidence interval: 0.546-0.753; p = 0.006), suggesting a modest model for the prediction of non-ST-elevation myocardial infarction using the red cell distribution width. At a cut-off value of 14%, the sensitivity and specificity of the red cell distribution width were 73% and 59%, respectively. Additionally, the red cell distribution width was positively correlated with cardiac troponin I (r = 0.19; p = 0.006).

CONCLUSION

A greater baseline red cell distribution width value was associated with myocardial injury and elevated cardiac troponin I levels in non-ST-elevation acute coronary syndrome. Therefore, the red cell distribution width could be considered for risk stratification of acute coronary syndrome patients admitted to emergency departments.

Red blood cell distribution width: A simple parameter with multiple clinical applications

The red blood cell distribution width (RDW) is a simple and inexpensive parameter, which reflects the degree of heterogeneity of erythrocyte volume (conventionally known as anisocytosis), and is traditionally used in laboratory hematology for differential diagnosis of anemias. Nonetheless, recent evidence attests that anisocytosis is commonplace in human disorders such as cardiovascular disease, venous thromboembolism, cancer, diabetes, community-acquired pneumonia, chronic obstructive pulmonary disease, liver and kidney failure, as well as in other acute or chronic conditions. Despite some demographic and analytical issues related to the routine assessment that may impair its clinical usefulness, an increased RDW has a high negative predictive value for diagnosing a variety of disorders, but also conveys important information for short- and long-term prognosis. Even more importantly, the value of RDW is now being regarded as a strong and independent risk factor for death in the general population. Although it has not been definitely established whether an increased value of RDW is a risk factor or should only be considered an epiphenomenon of an underlying biological and metabolic imbalance, it seems reasonable to suggest that the assessment of this parameter should be broadened far beyond the differential diagnosis of anemias. An increased RDW mirrors a profound deregulation of erythrocyte homeostasis involving both impaired erythropoiesis and abnormal red blood cell survival, which may be attributed to a variety of underlying metabolic abnormalities such as shortening of telomere length, oxidative stress, inflammation, poor nutritional status, dyslipidemia, hypertension, erythrocyte fragmentation and alteration of erythropoietin function. As such, the aim of this article is to provide general information about RDW and its routine assessment, to review the most relevant implications in health and disease and give some insights about its potential clinical applications.

Relationship between the red blood cell distribution width and risk of acute myocardial infarction

AIMS

Recently, a number of studies have shown an increased red blood cell distribution width (RDW) to be a strong and independent predictor of the prognosis of coronary artery disease. The aim of this study was to investigate the underlying mechanisms responsible for the relationship between the RDW and a poor prognosis of coronary artery disease.

METHODS

Four hundred and twenty-four patients with ST elevation myocardial infarction treated with primary percutaneous coronary intervention (pPCI) were analyzed retrospectively. We evaluated the relationships between the RDW and the high-sensitivity C-reactive protein (hsCRP) N-terminal pro-brain natriuretic peptide (NTpro-BNP), fasting blood glucose and lipid levels, as well as other parameters of blood examinations and angiographic manifestations.

RESULTS

There were 85 patients in the RDW ≥ 14% group (mean age 60.62 ± 11.29 years, and men: 87%) and 339 patients in the RDW ＜ 14% group (mean age: 59.74 ± 11.55 years, and men: 78%). The RDW ≥ 14% group had higher platelet distribution width (PDW), NTpro-BNP and hsCRP values on admission, a heavier intracoronary thrombotic burden and a higher incidence of three-branch vascular lesions than the RDW ＜ 14% group. In the multiple logistic regression analysis, the associations between the RDW and the NTpro-BNP level, incidence of three-branch and left main lesions and intracoronary thrombotic burden remained.

CONCLUSIONS

A high RDW may be associated with the severity and instability of acute myocardial infarction.

Mean platelet volume in patients with ischemic heart disease: meta-analysis of diagnostic studies

It is now widely acknowledged that larger platelets are biologically more active and express a greater prothrombotic potential, but there is no definitive evidence on the diagnostic accuracy role of mean platelet volume (MPV) in patients with ischemic heart disease. We performed an electronic search for articles that have assessed the diagnostic accuracy of MPV in patients admitted at the emergency department with a suspected diagnosis of ischemic heart disease, including articles in which the exact number of true-positive, false-positive, false-negative and true-negative test results could be either directly or indirectly extracted. Heterogeneity was assessed by I(2) test. The cumulative estimates and 95% confidence interval (95% CI) of sensitivity, specificity, negative predictive value (NPV), positive predictive value (PPV), area under the receiver operator characteristic (ROC) curve (AUC) and diagnostic odds ratio (DOR) were calculated using a random effect model. Three studies were finally included in our analysis (mean quality score, 10.8) totaling 3577 participants (566 cases and 3011 controls). The between-study variation was high (I(2), 96.2%; P < 0.001). The pooled estimates were 0.820 (95% CI 0.786-0.851) for sensitivity, 0.461 (95% CI 0.443-0.479) for specificity, 0.932 (95% CI 0.918-0.944) for NPV and 0.222 (95% CI 0.205-0.241) for PPV and 0.652 (95% CI 0.596-0.707) for AUC. The DOR was 3.9 (95% CI 2.3-6.5), with 0.52 diagnostic accuracy. The outcome of this meta-analysis suggests that MPV does not meet the requirements for efficient triage of patients in emergency department when used as stand-alone test, whereas its combination with high-sensitive troponin immunoassays merits further investigations.

The role of mean platelet volume in predicting thrombotic events

Studies on platelet function have accelerated and gained popularity since the advent of novel treatment modalities and techniques on atherosclerotic vascular disease, such as antiplatelet drugs and stents. Today it is widely known that platelets exert a fundamental role in inflammation in addition to their long known role in homeostasis and thrombotic events. Interaction with endothelial cells and leukocytes mediates inflammation, contributes to atherogenesis and modulates immune activity. Platelet activation which is a central factor in many arterial disorders may be triggered by multiple pathways. Platelet activation is shown as forming a larger shape, aggregation and releasing various active contents. Mean platelet volume is a marker of platelet size, function and activation. Increased mean platelet volume is shown by active and large platelets that release more thromboxane A2 than smaller ones. The aim of this review is to determine whether early detection of platelet activation via increased mean platelet volume would help to recognize the pro-inflammatory state and administer appropriate and effective treatment properly. An easily detectable marker by using a prompt and functional technique would help our approach to inflammation caused by platelets.