Red Blood Cell Distribution Width, Erythrocyte Indices, and Elongation Index at Baseline in a Group of Trained Subjects

BACKGROUND

Regular exercise elicits adaptive changes in several organs and physiological processes, including erythrocyte properties.

METHODS

In a group of 79 subjects (62 men and 17 women; mean age 31.37 ± 10.19 years) who trained several times a week as they practiced amateur sports, we evaluated the elongation index, markers of erythrocyte deformability, red blood cell distribution width (RDW), indicators of erythrocyte anisocytosis, hematocrit, hemoglobin, and the main erythrocyte indices (MCV, MCH, MCHC) in basal conditions.

RESULTS

In comparison with a group of healthy, but not training, volunteers, the values of the elongation index, and not the RDW, are increased, and this datum is accompanied by an increase in MCV and MCHC, likely related to an increased presence of circulating young erythrocytes in training subjects. We also divided the same group according to the median of the VO2max, observing that the subgroup above the median shows both an increase in the elongation index values and a decrease in MCH and MCHC.

CONCLUSIONS

In trained subjects, there is no correlation between the values of the elongation index and the RDW, while the interrelations among the elongation index, RDW, and main erythrocyte indices appear to be of particular interest and of a certain complexity.

Hematological parameters: is there a difference between those released by the hematological analyzer and to the customer?

OBJECTIVE

This study aimed to compare the hematological parameters released by hematological analyzers with those released in customer reports.

METHODS

We conducted a descriptive study in the laboratories of a medium-sized municipality in the state of Minas Gerais registered in the National Register of Health Establishments. Interviews were conducted using a questionnaire to obtain information regarding the parameters released by the analyzers and those available in the customer's report.

RESULTS

Sixteen laboratories were evaluated, and none of them released all the parameters obtained from the hematological analyzers to customers. The red blood cell distribution width was released in 88% of the laboratories, atypical lymphocytes in 70%, mean platelet volume in 50%, platelet distribution width and platelet count in 20%. No laboratory released information on reticulocytes, fraction of immature reticulocytes and immature granulocytes, nucleated erythrocyte count, immature platelet fraction and reticulocyte hemoglobin, and large platelet rate.

CONCLUSION

All evaluated clinical analysis laboratories had at least one parameter that was not released in the customer's report despite being released by the hematological analyzers. The lack of knowledge on the part of professionals about the clinical importance of each parameter of the complete blood count results in a loss in patient assessment, and it is important to include these parameters in the complete blood count report.

DIAGNOSIS OF ACUTE APPENDICITIS AND APPENDICULAR PERFORATION: EVALUATION OF PLATELET INDICES AND RED CELL DISTRIBUTION WIDTH AS EMERGING BIOMARKERS

BACKGROUND

Acute appendicitis is a common surgical emergency worldwide. Recent studies on hematological inflammatory markers concerning acute appendicitis have shown variable results.

AIMS

The aim of this study was to evaluate pre-operative values of platelet indices such as mean platelet volume (MPV) and platelet distribution width (PDW), and red cell distribution width (RDW) in relation to the diagnosis of acute appendicitis and their efficacy as predictors of appendicular perforation.

METHODS

A prospective observational study of 190 patients diagnosed with appendicitis and who underwent an appendectomy was undertaken and confirmed histopathologically. Preoperatively, blood samples of white blood cells (WBCs), platelet count, MPV, PDW, and RDW were analyzed using a Sysmex XN1000 analyzer machine.

RESULTS

Of 190 patients, 169 had acute appendicitis, and 21 had perforated appendicitis. The mean age of patients was 28.04 ± 14.2 years. The male-to-female ratio was 1.5:1. The WBC (p<0.05), MPV (p<0.05), and PDW (p<0.05) were found to have higher statistically significant values in acute appendicitis and perforated appendicitis compared to the RDW (p>0.05). However, perforated appendicitis had a higher RDW value compared to acute appendicitis, which can be a predictive factor.

CONCLUSIONS

The elevated value of MPV and PDW associated with leukocytosis can be used as supportive evidence for the clinical and radiological diagnosis of acute appendicitis and appendicular perforation. Thus, these values can be used as diagnostic cost-effective inflammatory biomarkers.

A light scatter based model relating erythrocyte vesiculation to lifetime in circulation

Methods for measuring erythrocyte age distribution are not available as a simple analytical tool. Most of them utilize the fluorescence or radioactive isotopes labeling to construct the age distribution and support physicians with aging indices of donor's erythrocytes. The age distribution of erythrocyte may be a useful snapshot of patient state over 120-days period of life. Previously, we introduced the enhanced assay of erythrocytes with measurement of 48 indices in four categories: concentration/content, morphology, aging and function (10.1002/cyto.a.24554). The aging category was formed by the indices based on the evaluation of the derived age of individual cells. The derived age does not exactly mean the real age of erythrocytes and its evaluation utilizes changes of cellular morphology during a lifespan. In this study, we are introducing the improved methodological approach that allows us to retrieve the derived age of individual erythrocytes, to construct the aging distribution, and to reform the aging category consisting of eight indices. The approach is based on the analysis of the erythrocyte vesiculation. The erythrocyte morphology is analyzed by scanning flow cytometry that measures the primary characteristics (diameter, thickness, and waist) of individual cells. The surface area (S) and sphericity index (SI) are calculated from the primary characteristics and the scattering diagram SI versus S is used in the evaluation of the derived age of each erythrocyte in a sample. We developed the algorithm to evaluate the derived age that provides eight indices in the aging category based on a model using light scatter features. The novel erythrocyte indices were measured for simulated cells and blood samples of 50 donors. We determined the first-ever reference intervals for these indices.

Comparison of Biochemical, Haematological and Plasmatic Butyrylcholinesterase Parameters in Farmers and Non-Farmers, Morocco

Background

The long-term use of pesticides can cause harmful consequences to both human health and the environment. In the present research, we aimed to compare biochemical, hematological, and plasmatic measurements of butyrylcholinesterase (BChE) between farmers and non-farmers.

Materials and Methods

The study is cross-sectional and included 270 participants, with 135 farmers using pesticides and a control population of 135 non-farmers. The recruitment of the participants was conducted from August 2017 to the end of December 2019. Blood samples from participants were collected for the evaluation of biochemical markers of the function of the liver and determination of BChE activity. A whole blood sample with ethylenediamine tetraacetic anticoagulant (EDTA) was also taken for a complete blood count.

Results

The results showed a statistically significant (P = 0.03) decrease in mean corpuscular hemoglobin (MCH) in the cases (28.45 ± 2.94 pg) as compared with controls (29.17 ± 2.54 pg). The statistical analysis of the renal parameters between the two groups determined that the uremia value was significantly higher in cases (34 ± 12 mg/dL) when compared to the control group (29 ± 8 mg/dL) P < 0.001. The cases recorded a significant increase in aspartate aminotransferase (AST) (26.22 ± 11.59 U/L) and alanine aminotransferase (ALT) (25.63 ± 13.47 U/L) enzyme activities among cases versus controls. The results obtained showed a significantly decreased BChE activity in the group of cases exposed to pesticides (7554.52 ± 2107 U/l) compared to the unexposed control group (10135.58 ± 1909 U/l) (t-test, P < 0.001).

Conclusion

The education of the farmers on correct practices concerning phytosanitary use has the potential of reducing their exposure to these products.

Additional value of red blood cell parameters in predicting uncommon α-thalassemia; experience from 10 years of α-globin gene sequencing and copy number variation analysis

INTRODUCTION

The diagnosis of rare forms of α-thalassemia requires laborious genetic analyses. Accurate sample selection for such evaluation is therefore essential. The main objectives of this study were to investigate the predictive power of red blood cell parameters to detect rare forms of α-thalassemia (substudy 1), and to explore the frequency of rare versus common forms of α-thalassemia in our sample population (substudy 2).

METHODS

In substudy 1, we reviewed all blood samples selected for extended α-hemoglobinopathy evaluation at our laboratory during 2011-2020 (n = 1217), which included DNA sequencing and/or copy number variation analysis. We assessed α-thalassemia positive samples at different levels of mean corpuscular hemoglobin (MCH) alone and in combination with results for red blood cell count (RBC) or red cell distribution width (RDW). In substudy 2, we examined the distribution of α-thalassemia genotypes for all samples submitted to a first-tier hemoglobinopathy evaluation at our laboratory during 2014-2020 (n = 6495).

RESULTS

In substudy 1, both RBC and RDW added predictive value in detecting rare forms of α-thalassemia in samples from adults and children. In adult samples with MCH ≤ 23 pg, the presence of erythrocytosis increased the detection rate from 27% to 74% as compared to non-erythrocytosis, while normal RDW increased the detection rate from 36% to 86% as compared to elevated RDW. In substudy 2, rare forms of α-thalassemia were detected in 12% of α-thalassemia positive samples.

CONCLUSION

Initial assessment of MCH, RBC, and RDW provided valuable predictive information about the presence of rare forms of α-thalassemia during hemoglobinopathy evaluation.

Investigation of the relationship between red blood cell distribution width and mortality in patients with hemophagocytic lymphohistiocytosis: a retrospective study

BACKGROUND

Red blood cell distribution width (RDW) is related to sepsis-related mortality. Hemophagocytic lymphohistiocytosis (HLH) is a syndrome caused by severe infection, tumors, or autoimmunity without a specific diagnosis.

OBJECTIVE

To explore the correlation between RDW and mortality in patients with HLH.

DESIGN AND SETTING

A retrospective study conducted in a hospital in China.

METHODS

A total of 101 inpatients with HLH from January 1, 2017 to December 31, 2021 were divided into non-survivor (n = 52) and survivor (n = 49) groups. A non-parametric test was used to analyze demographic, clinical, and laboratory data between groups. Independent variables with P < 0.05 were analyzed using binary logistic regression to screen out mortality-related variables. Selected variables were subjected to multivariate logistic regression analysis, and those with strong correlations were screened. Receiver operating characteristic (ROC) curves of strongly correlated variables and area under curve (AUC) values were obtained.

RESULTS

The APACHE II score, RDW, and platelet (PLT) and fibrinogen (FIB) levels (P < 0.05) different significantly. RDW, PLT, FIB were correlated with mortality. The AUC values of RDW, PLT, and FIB were 0.857, 0.797, and 0.726, respectively. RDW was associated with mortality in patients with HLH (P < 0.01, cut-off value: 16.9). The sensitivity and specificity of predicting mortality were 97.96% and 96.1%, respectively.

CONCLUSION

Logistic regression analysis showed a correlation between RDW and patients' mortality. Therefore, RDW can be used to predict mortality in patients with HLH.

Erythrocyte lysis and angle-resolved light scattering measured by scanning flow cytometry result to 48 indices quantifying a gas exchange function of the human organism

Molecular/cell level of gas exchange function assumes the accurate measurement of erythrocyte characteristics and rate constants concerning to molecules involved into the CO₂ /O₂ transport. Unfortunately, common hematology analyzers provide the measurement of eight indices of erythrocytes only and say little about erythrocyte morphology and nothing about rate constants of cellular function. The aim of this study is to demonstrate the ability of the Scanning Flow Cytometer (SFC) in the complete morphological analysis of mature erythrocytes and characterization of erythrocyte function via measurement of lysing kinetics. With this study we are introducing 48 erythrocyte indices. To provide the usability of application of the SFC in clinical diagnosis, we formed four categories of indices which are as follows: content/concentration (9 indices), morphology (26 indices), age (5 indices), and function (8 indices). The erythrocytes of 39 healthy volunteers were analyzed with the SFC to fix the first-ever reference intervals for the new indices introduced. The essential measurable reliability of the presented method is expressed in terms of errors of characteristics of single erythrocytes retrieved from the solution of the inverse light-scattering problem and errors of parameters retrieved from the fitting of the experimental kinetics by molecular-kinetics model of erythrocyte lysis.

Effectiveness of screening endoscopy for esophageal squamous cell carcinoma in Japanese males

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) has a poor prognosis; therefore, early detection is essential. In Japan, more than 90% of esophageal cancers are ESCC. Endoscopy is effective to detect ESCC in the early stage, but there is a limited number of reports examining its efficacy and effectiveness.

OBJECTIVE

This study aimed to evaluate the efficacy of screening endoscopy for detecting ESCC.

METHODS

This retrospective study analyzed the prevalence of ESCC, annual transition of prevalence, and the stage of each ESCC among 128,520 medical check-up patients who underwent esophagogastroduodenoscopy from April 2015 to March 2020 at Yamanashi Koseiren Health Care Center. Furthermore, a case-control study utilized the multivariate logistic regression analysis was performed to assess the risk factor of ESCC.

RESULTS

Among a total of 128,520 subjects, 42 ESCC patients were detected, with 95.2% being diagnosed at early stages. Annual prevalence in males was 0.015% (2/13,122) in 2015, 0.044% (6/13,562) in 2016, 0.044% (6/13,676) in 2017, 0.074% (10/13,488) in 2018%, and 0.11% (16/14,386) in 2019. ESCC prevalence has been increasing each year. A significant increase was observed between 2015 and 2018 (p = 0.039). ESCC prevalence was 0.102% (25/24,272) when focusing on males aged over 50 years with a history of smoking and drinking. Regarding the case-control study, the multivariate logistic regression analysis revealed smoking (p = 0.044), mean corpuscular volume (MCV) (p = 0.0018), and severe gastric atrophy (p = 0.048) as positively correlated with ESCC.

CONCLUSION

In conclusion, ESCC has been increasing in our center from 2015 to 2019, and the prevalence has been approaching that of gastric cancer in 2019 in male subjects. ESCC can be detected efficiently by targeting males with high MCV who have a history of drinking and smoking.

Erythrocyte Indices in Creutzfeldt-Jakob Disease Predict Survival Time

Background

Creutzfeldt–Jakob disease (CJD) is a devastating neurodegenerative disease caused by propagation of abnormally folded prion proteins (PrP^Sc). Some fluid biomarkers have been reported to be associated with disease duration in CJD. Based on studies which have found that prion protein (PrP^C) played a role in erythrocytic hematopoiesis, we evaluated the association between peripheral red blood cell indices and survival time in CJD.

Methods

We retrospectively collected data on peripheral red blood cell indices, including red blood cell (RBC) count, hemoglobin (Hb), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW), from 125 CJD patients. Cox proportional hazard models were generated to determine whether red cell indices correlated with survival time of patients with CJD.

Results

Of the 125 included participants, 70 (56%) were male, and the mean age at diagnosis (SD) was 60.3 (9.5) years. Hemoglobin levels (hazard ratio 1.710, 95% CI 1.124–2.600, p = 0.012) and HCT (hazard ratio 1.689, 95% CI 1.112–2.565, p=0.014) were significantly associated with survival time after controlling for sex, age, and Barthel Index. Red blood cell count, MCV, MCH, MCHC, and RDW were not associated with survival time before or after adjusting for covariates.

Conclusions

Our study found that Hb and HCT were significantly associated with survival time in patients with CJD. These results may inform evaluation of the mechanisms of interaction between prion disease and hematopoiesis, and indicate that Hb and HCT may be potential prognostic biomarkers.

Effect of microaggregate filter passage on feline whole blood stored for 35 days

OBJECTIVES

The aim of this study was to compare the characteristics of fresh and stored feline red blood cells (RBCs) after passage through an 18 μm microaggregate filter.

METHODS

Nine cats were recruited for a single blood donation using an open collection system. A simulated transfusion using a syringe driver and microaggregate filter was performed over 2 h with half the blood on the day of donation and the other half after 35 days of storage. Differences in haematological parameters, haemolysis percentage and osmotic fragility (OF) were compared on the day of donation pre-filter passage (D0-) vs day of donation post-filter (D0+) or day 35 storage pre-filter (D35-) and post-filter (D35+). Blood was cultured at D0+ and D35+.

RESULTS

There were no statistically significant differences in the D0- vs D0+ comparisons. There were statistically significant (P <0.05) increases in haemolysis percentage, red cell distribution width (RDW) percentage and mean OF, and decreases in packed cell volume (PCV), RBC count, haemoglobin and haematocrit for D0- vs D35-. The same was found for D0- vs D35+ with the addition of a significant increase in mean cell haemoglobin (MCH). For D35- vs D35+ only MCH significantly increased. At day 35, 6/9 units had haemolysis percentages that exceeded 1%. This increased to 8/9 of stored units post-filter passage. All blood units cultured negative.

CONCLUSIONS AND RELEVANCE

Fresh RBCs exhibited no in vitro evidence of injury following passage through an 18 μm microaggregate filter. Increased MCH was observed in the stored blood and may represent haemolysis induced by the filter. All other changes can be explained by storage lesion rather than filter passage. The findings highlight the importance of blood banking quality controls and the need for further research to assess the effects of transfusion technique, specifically filter passage, on storage lesion-affected feline blood.

Exposure to heavy metals and red blood cell parameters in children: A systematic review of observational studies

BACKGROUND

Mechanistic studies show that heavy metals interfere with the hematopoietic system by inhibiting key enzymes, which could lead to anemia. However, the link between children's exposure and red blood cell (RBC) parameters has been inconsistent. We aimed to summarize evidence on human studies exploring the association between exposure to lead, mercury, cadmium, arsenic, and chromium VI and RBC parameters in children.

METHODS

Following the PRISMA guidelines, we searched PubMed, Scopus, and Web of Science databases for studies published between January 2010 and April 2022. Eligible papers included human observational studies that directly assessed exposure (internal dose) to the heavy metals under study and RBC parameters in participants aged ≤ 18 years. We excluded studies using hospital-based samples. Study quality was assessed using the National Institutes of Health's Quality Assessment Tools for Cohort and Cross-Sectional Studies. We synthesized the evidence using vote counting based on the direction of the relationship.

RESULTS

Out of 6,652 retrieved papers, we included a total of 38 (33 assessing lead, four mercury, two cadmium, and two arsenic; chromium VI was not assessed in any included paper). More than half of the studies were conducted in Asia. We found evidence of a positive relationship between lead concentration and hemoglobin (proportion of studies reporting negative relationships = 0.750; 95% Confidence Interval (CI) 0.583, 0.874) and mean corpuscular hemoglobin (0.875; 95% CI 0.546, 0.986), and a positive relationship with red cell distribution width (0.000; 95%CI 0.000, 0.379). When considering only good-quality studies (24% of the Pb studies), only the relationship with hemoglobin levels remained (0.875; 95% CI: 0.546, 0.986).

CONCLUSION

We found evidence of a negative relationship between lead concentration and hemoglobin and mean corpuscular hemoglobin and of a positive relationship with red cell distribution width in children. We also identified a need to conduct more studies in European countries. Future studies should use standardized practices and make efforts to increase study quality, namely by conducting comprehensive longitudinal studies. Our findings support the need to take further actions to limit heavy metal exposure during childhood.

The accuracy of mean corpuscular volume guided anaemia classification in primary care

BACKGROUND

Anemia can be categorized into micro-, normo- or macrocytic anemia based on the mean corpuscular volume (MCV). This categorization might help to define the etiology of anemia.

METHODS

The cohort consisted of patients newly diagnosed with anaemia in primary care. Seven aetiologies of anaemia were defined, based on an extensive laboratory protocol. Two assumptions were tested: (i) MCV <80 fl (microcytic) excludes vitamin B12 deficiency, folic acid deficiency, suspected haemolysis and suspected bone marrow disease as anaemia aetiology. (ii) MCV >100 fl (macrocytic) excludes iron deficiency anaemia, anaemia of chronic disease and renal anaemia as anaemia aetiology.

RESULTS

Data of 4129 patients were analysed. One anaemia aetiology could be assigned to 2422 (59%) patients, more than one anaemia aetiology to 888 (22%) patients and uncertainty regarding the aetiology remained in 819 (20%) patients. MCV values were within the normal range in 3505 patients (85%). In 59 of 365 microcytic patients (16%), the anaemia aetiology was not in accordance with the first assumption. In 233 of 259 macrocytic patients (90%), the anaemia aetiology was not in accordance with the second assumption.

CONCLUSIONS

Anaemia aetiologies might be ruled out incorrectly if MCV guided classification is used as a first step in the diagnostic work-up of anaemia. We recommend using a broader set of laboratory tests, independent of MCV.

SARS-COV-2 Infection in Children and Red Blood Cell Distribution Width

SARS-COV-2 infection due to Coronavirus is highly contagious and causes varying degrees of illness throughout the world. Recent literature has shown an association between red blood cell distribution width (RDW) and adverse outcomes among adult patients with COVID-19. Multiple hypotheses can explain the potential prognostic role of RDW in COVID-19 infection. The aim of this study is to describe RDW values in SARS-COV-2 infected children admitted to the Pediatric Emergency Department to shed light on the potential role of RDW as a prognostic factor in this specific group. Of 1086 tested children observed from March 2020 to April 2021, 36 positive SARS-COV-2 children (0-16 years) did not show clinically significant differences in RDW values according to illness categories, days of hospitalization, presence of multisystem inflammatory syndrome in children (MIS-C), or viral load (cycle threshold (CT) values). This study is the first to investigate this issue in a SARS-COV-2 infected pediatric population. Despite our negative results, given the high incidence of Delta variant in children, the low cost of the examination, its prognostic role described in adults, and its association to other pediatric illnesses, we believe that the role of RDW in SARS-COV-2 infected children should be deeper assessed and that larger collaborative studies on this issue are required.

An Experimental Model for Iron Deficiency Anemia in Sows and Offspring Induced by Blood Removal during Gestation

Anemia is a common condition in sow herds. We aimed to study the effects of severe iron deficiency during gestation on sow and piglet health outcomes with an experimental model for blood-removal-induced iron deficiency anemia. In total, 18 multiparous sows (8 in trial I and 10 in trial II) were allocated to either a blood removal group or a control group. Hematologic parameters were monitored at regular intervals and the tissue iron concentrations were measured for the sows and newborn piglets after farrowing. In trial I, the mean liver iron content was reduced to 46.7 µg/g in the blood removal sows compared to 252.6 µg/g in the controls (p < 0.001). In trial II, sows in the blood removal group had lower iron content in the liver (147.8 µg/g), kidney (46.3 µg/g) and spleen (326.5 µg/g) compared to the control sows (323.2 µg/g, 81.3 µg/g and 728.9 µg/g, respectively; p = 0.009, 0.016, 0.01, respectively). In trial I, piglets from sows in the blood removal group had significantly decreased hematocrit (Hct), red blood cells (RBC) and a tendency for reduced hemoglobin (Hb) compared to the control piglets. We established a blood removal model that resulted in mild- to severe degrees of sow anemia and reduced tissue iron stores at farrowing.

Red Cell Distribution Width as a Prognostic Factor and Its Comparison with Lactate in Patients with Sepsis

Sepsis remains the leading cause of death in critically ill patients. Thus, regular measurement of lactate levels has been proposed in sepsis guidelines. Elevated red cell distribution width (RDW) is associated with mortality risk in patients with sepsis. This study aimed to investigate the association between RDW and the risk of other adverse outcomes in patients with sepsis and to compare the mortality discriminative ability between lactate and RDW levels. This is a single-centered, retrospective, case-control study that included 504 adult patients with sepsis in the emergency department between 1 January 2020 and 31 December 2020. Eligible patients were divided into normal (RDW ≤ 14.5%) and high (RDW > 14.5%) groups. The baseline characteristics and adverse outcomes were recorded and compared. Compared with the normal RDW group, the patients in the high RDW group had a significantly higher rate of ICU admission (48.8% vs. 32.4%, p = 0.03), septic shock (39.2% vs. 23.5%, p < 0.01), and 30-day in-hospital mortality (32.0% vs. 20.7%, p < 0.01). Furthermore, the RDW (area under curve (AUC) = 0.71) had superior mortality discriminative ability compared to lactate (AUC = 0.63) levels (p = 0.02). Clinicians could rely on this simple and rapid parameter for risk stratification to initiate prompt treatment for patients with sepsis.

Multi-Approach Assessment for Stress Evaluation in Rainbow Trout Females, Oncorhynchus mykiss (Walbaum, 1792) from Three Different Farms during the Summer Season

Blood biochemistry parameters are valuable tools for monitoring fish health. Their baseline values are still undefined for a multitude of farmed fish species. In this study, changes in the blood profile of rainbow trout females (Oncorhynchus mykiss) from three farms were investigated using different biomarkers during the summer season. In the given context, the main water physicochemical parameters were investigated and twelve biochemical parameters were measured from blood samples of rainbow trout reared in the Fiad, Șoimul de Jos, and Strâmba farms. We selected these farms because the genetic background of the rainbow trout is the same, with all studied specimens coming from the Fiad farm, which has an incubation station. Forty-five samples were collected monthly (May to August) throughout summer to observe the changes in the blood profile of rainbow trout. Principal component analysis showed a clear separation both among the studied farms and months. Furthermore, significant correlations (p < 0.05) between the majority of the biochemical parameters were found, indicating that the environmental parameters can influence several blood parameters at the same time. The present study provides several useful norms for assessing the welfare of rainbow trout, indicating that the relationships among different parameters are important factors in interpreting the blood biochemical profiles.

Association between red blood cell distribution width and mortality and severity among patients with COVID-19: A systematic review and meta-analysis

Emerging evidence has underscored the potential usefulness of red blood cell distribution width (RDW) measurement in predicting the mortality and disease severity of COVID‐19. This study aimed to assess the association of the plasma RDW levels with adverse prognosis in COVID‐19 patients. A comprehensive literature search from inception to September 2020 was performed to harvest original studies reporting RDW on admission and clinical outcomes among patients hospitalized with COVID‐19. RDW levels were compared between cases (patients who died or developed more severe symptoms) and controls (patients who survived or developed less severe symptoms). A total of 14,866 subjects from 10 studies were included in the meta‐analysis. Higher levels of RDW were associated with adverse outcomes in COVID‐19 patients (mean differences = 0.72; 95% CI = 0.47–0.97; I² = 89.51%). Deceased patients had higher levels of RDW compared to patients who survived (mean differences = 0.93; 95% CI = 0.63–1.23; I² = 85.58%). Severely ill COVID‐19 patients showed higher levels of RDW, as opposed to patients classified to have milder symptoms (mean differences = 0.61; 95% CI = 0.28–0.94; I² = 82.18%). Elevated RDW levels were associated with adverse outcomes in COVID‐19 patients. This finding warrants further research on whether RDW could be utilized as a simple and reliable biomarker for predicting COVID‐19 severity and whether RDW is mechanistically linked with COVID‐19 pathophysiology.

Hematological Parameters and Clinical Features in Patients with Advanced Chronic Kidney Disease

Background

Hematological parameters like red cell distribution width (RDW) and mean platelet volume (MPV) were reported to be associated with inflammation, atherosclerosis, and chronic kidney disease (CKD) progression. In this study, we evaluated RDW and MPV along with clinical features in patients with advanced CKD. We also aimed to detect clues for causative relations concerning these parameters, renal function and comorbidities.

Methods

Stage 3-5 CKD patients (627 total) were included (mean age 63.1 years, 48.3% male). Patients with malignancies, cirrhosis, infections, severe anemia, and systemic inflammation were excluded. Patients were evaluated for clinical features and grouped for comparison using median RDW and MPV. Linear regression models were generated to predict potential influences on RDW and MPV.

Results

Mean estimated glomerular filtration rate (eGFR) was 27.3 mL/min/1.73m². Mean Charlson Comorbidity Index (CCI) score was 5.83 ± 2.06. Patients with high RDW (n = 303) were older with higher CRP and CCI, they also had lower eGFR, hemoglobin, and albumin (P < 0.001 for all). Patients with low MPV (n = 311) had lower eGFR, and platelet counts (P = 0.015 and 0.017). eGFR was negatively correlated with RDW after adjusting for age, gender and comorbidities. In a further adjusted model RDW was associated with CRP, CCI, hemoglobin and albumin (P < 0.05 for all), not with eGFR. MPV was positively correlated with eGFR in our adjusted, and fully adjusted regression models (P = 0.003).

Conclusion

In this study, we found that high RDW is associated with comorbidity burden, anemia, and inflammatory status in patients with advanced CKD. Meanwhile, low MPV seems to be associated with worse renal function.

Evaluation of the usefulness of red blood cell distribution width in critically ill pediatric patients

Red blood cell distribution width (RDW) is a component of routine complete blood count, which reflects variability in the size of circulating erythrocytes. Recently, there have been many reports about RDW as a strong prognostic marker in various disease conditions in the adult population. However, only a few studies have been performed in children. This study aimed to investigate the association between RDW and pediatric intensive care unit (PICU) mortality in critically ill children. This study includes 960 patients admitted to the PICU from November 2012 to May 2018. We evaluated the associations between RDW and clinical parameters including PICU mortality outcomes. The median age of the study population was 15.5 (interquartile range, 4.8-54.5) months. The mean RDW was 15.6% ± 3.3%. The overall PICU mortality was 8.8%. As we categorized patients into 3 groups with respect to RDW values (Group 1: ≤14.5%; Group 2: 14.5%-16.5%; and Group 3: >16.5%) and compared clinical parameters, the higher RDW groups (Groups 2 and 3) showed more use of vasoactive-inotropic drugs, mechanical ventilator support, higher severity scores, including pediatric risk of mortality III, pediatric sequential organ failure assessment, pediatric logistic organ dysfunction-2 (PELOD-2), and pediatric multiple organ dysfunction syndrome scores, and higher PICU mortality than the lower RDW group (Group 1) (P < .05). Based on multivariate logistic regression analysis adjusted for age and sex, higher RDW value (≥14.5%) was an independent risk factor of PICU mortality. Moreover, adding RDW improved the performance of the PELOD-2 score in predicting PICU mortality (category-free net reclassification index 0.357, 95% confidence interval 0.153-0.562, P = .001). In conclusion, higher RDW value was significantly associated with worse clinical parameters including PICU mortality. RDW was an independent risk factor of PICU mortality and the addition of RDW significantly improved the performance of PELOD-2 score in predicting PICU mortality. Thus, RDW could be a promising prognostic factor with advantages of simple and easy measurement in critically ill pediatric patients.

Role of RDW in mathematical formulas aiding the differential diagnosis of microcytic anemia

Many mathematical formulas containing simple red blood cell parameters have been proposed for differentiating between iron deficiency and thalassemia in patients with microcytic anemia. Approximately half of these formulas do include red cell distribution width (RDW), along with other red cell parameters. In the present study we investigated the role of RDW, expressed in relative or in absolute units in relation with the formulas' discriminant performance. We used a database containing over 2200 subjects with microcytic anemia, for whom a final diagnosis (iron-deficiency anemia, thalassemia, both or other) was available. Performance of the discriminant formulas was assessed by Receiver Operator Curve analysis. Substitution of relative by absolute RDW resulted in statistically significant performance increase (area under the ROC curve) in 16 out of 23 formulas, predominantly due to increased specificity. Relevant performance deterioration was seen in only three formulas that had low initial performance already with the original relative RDW. For optimal differential diagnostic performance, an RDW-based formula for distinguishing thalassemia from iron-deficiency anemia in microcytic anemia should contain 'absolute' instead of relative RDW.

Red Blood Cell Distribution Width Is Associated with All-Cause Mortality in Critically Ill Patients with Cardiogenic Shock

BACKGROUND There is no previously published epidemiological study exploring the association between red blood cell distribution width (RDW) and mortality in patients with cardiogenic shock (CS). The aim of this study was to examine the association between RDW and the risk of all-cause mortality in these patients. MATERIAL AND METHODS We analyzed clinical data from the MIMIC-III V1.4 database. We collected data on each patient's demographic parameters, vital signs, laboratory parameters, vital signs, comorbidities, and scoring systems on ICU admission. Cox proportional hazards models were used to assess the association between RDW levels and the 30-day, 90-day, and 365-day mortality in patients with CS. RESULTS There were 1131 patients meeting inclusion criteria in our study. In multivariate analysis, following adjustment for age, sex, and ethnicity, higher RDW in tertiles and quintiles were all associated with increased risk of 30-day, 90-day, and 365-day all-cause mortality. Furthermore, after adjusting for more relevant confounders, RDW remained a significant predictor of risk of 30-day, 90-day, and 365-day mortality (tertile 3 versus tertile 1: HR, 95% CI: 1.66, 1.19-2.31; 1.73, 1.28-2.33; 1.80, 1.38-2.34). Similarly significant robust associations were found in RDW levels stratified by quintiles. CONCLUSIONS Higher RDW is associated with increased risk of all-cause mortality in critically ill patients with CS.

Unbiased Phenome-Wide Association Studies of Red Cell Distribution Width Identifies Key Associations with Pulmonary Hypertension

Rationale: Red cell distribution width (RDW) is a prognostic factor in many diseases; however, its clinical utility remains limited because the relative value of RDW as a biomarker across disease states has not been established. Objectives: To establish an unbiased RDW disease hierarchy to guide the clinical use of RDW and to assess its relationship to cardiovascular hemodynamic and structural parameters. Methods: We performed phenome-wide association studies for RDW in discovery and replication cohorts derived from a deidentified electronic health record in nonanemic individuals. RDW values obtained within 30 days of echocardiogram or right heart catheterization were tested for association with structural and hemodynamic variables. Results: RDW was associated with 263 phenotypes in both men and women in the discovery cohort (n = 121,530), 48 of which replicated in an independent cohort (n = 2,039). The strongest associations were observed with pulmonary arterial hypertension (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.9-2.3), chronic pulmonary heart disease (OR, 2.0; 95% CI, 1.9-2.2), and congestive heart failure (OR, 1.9; 95% CI, 1.8-2.0); P < 1 × 10-74 for all. By echocardiography, RDW was higher in the setting of right ventricular dysfunction than left ventricular dysfunction (P < 0.001). Measured invasively, mean pulmonary arterial pressure was associated with RDW (21 vs. 33 mm Hg at 25th vs. 75th percentile RDW; P < 1 × 10-7) and remained strongly significant even when controlling for mean pulmonary capillary wedge pressure (21 vs. 29 mm Hg at 25th vs. 75th percentile RDW; P < 1 × 10-7). Conclusions: Among 1,364 coded medical conditions, increased RDW was strongly associated with pulmonary hypertension and heart failure. Hemodynamic and echocardiographic phenotyping confirmed these associations and underscored that the most clinically relevant phenotype associated with RDW was pulmonary hypertension. These hypothesis-generating findings highlight the potential shared pathophysiology of pulmonary hypertension and elevated RDW. Elevated RDW in the absence of anemia should alert clinicians to the potential for underlying cardiopulmonary disease.

Storage stability of commonly used haematological parameters at 33 °C: Electronic supplementary material available online for this article

Introduction

This study aimed to investigate the analytical bias in haematological parameters induced by storage at 33 ºC.

Materials and methods

Blood from the diversion pouch of 20 blood donors were collected in K₂EDTA vials and stored at 33 ºC. Readings from each vial were taken at 0, 4, 6, 12, 24, 48 and 72 hours after collection on the Sysmex XP-100 analyser (Sysmex Corporation, Kobe, Japan). The percent difference from the baseline readings were calculated and subjected to a Wilcoxon signed rank test at a Holm corrected significance level of 0.05. A median percent difference, which was statistically significant and greater than the maximum acceptable bias (taken from studies of biological variation), was taken as evidence of unacceptable shift. If the median shift was lesser than the maximum acceptable bias, two one-sided Wilcoxon signed rank tests for equivalence were used to determine whether the percent differences were significantly lesser than the maximum acceptable bias.

Results

Haemoglobin, red blood cell count, white blood cell count, mean corpuscular haemoglobin and lymphocyte count showed acceptable bias after storage for at least 24 hours at 33 ºC. Haematocrit, mean corpuscular volume, mean corpuscular haemoglobin concentration, platelet count and mean platelet volume showed unacceptable shift in less than 4 hours when stored at 33 ºC.

Conclusions

Since many haematological parameters show unacceptable bias within 4 hours of sample storage at 33 ºC, the recommended limit of time from collection to processing should be revised for areas where high environmental temperatures are common.

The association between red cell distribution width and venous thromboembolism is not explained by myocardial infarction, stroke, or cancer

BACKGROUND

Red cell distribution width (RDW) is a risk marker of venous thromboembolism (VTE), myocardial infarction (MI), stroke, and cancer. Due to interrelations between these diseases, the association between RDW and VTE may be explained by MI, stroke, or cancer.

OBJECTIVE

To investigate whether the effect of RDW on VTE could be explained by intermediate development of MI, stroke, or cancer.

METHODS

RDW was measured in 24 363 participants of the Tromsø Study in 1994-1995. Incident VTE, MI, stroke, and cancer were registered until December 31, 2010. Conventional and cause-specific Cox-regression models were used to estimate hazard ratios (HR) for VTE with 95% confidence intervals (CI) across categories of RDW.

RESULTS

There were 502 first VTEs during a median follow-up of 16 years. In conventional Cox regression analysis, RDW in the highest quartile was associated with a 71% (HR 1.71, 95% CI 1.09-2.67) and 27% (HR 1.27, 95% CI 0.88-1.85) higher risk of VTE in men and women, respectively, compared to subjects in the lowest quartiles. The risk of VTE among subjects with RDW in the highest quartile was similar for men and women of postmenopausal age. In cause-specific analysis, where each individual contributed with person-time until the first occurring event only, the risk estimates were similar to those of the conventional Cox-regression analysis.

CONCLUSION

Our findings suggest that the association between RDW and future risk of VTE is not explained by intermediate development of MI, stroke, or cancer.

Causes of microcytic anaemia and evaluation of conventional laboratory parameters in the differentiation of erythrocytic microcytosis in blood donors candidates

CONTEXT AND OBJECTIVE

Microcytic anaemia results from defective synthesis of haemoglobin in the erythroid precursors, causing a reduction in its mean corpuscular volume (MCV). The most common causes of microcytosis, without the increase in HbA₂ levels, are iron deficiency anaemia (IDA) and α-thalassemia. The aim of this study was to identify the causes of microcytic anaemia and evaluate the haematological parameters from blood donors deemed ineligible (due to the low haematocrit level) that would differentiate the IDA and α-thal, whether isolated or in association.

METHODS

Genomic DNA was submitted to the polymerase chain reaction multiplex for the diagnosis of the most common allele deletions of α-thal and erythrogram and in order to verify haematological parameters. Iron deficiency (ID) was determined through the measurement of serum ferritin.

RESULTS

Of the 204 samples, 82 (40.2%) were identified with ID, 24 (17.8%) with α-thal and 10 (4.9%) with ID associated with α-thal. In the α-thal with ID group haemoglobin (Hb), MCV, mean corpuscular Hb concentration (MCHC) and mean corpuscular Hb (MCH) values were significantly lower compared to the isolated α-thal. In the group with ID Hb, MCV, MCHC and MCH values were significantly lower compared to those with isolated α-thal. The α-thal with ID group, showed Hb, MCV, MCHC and MCH significantly reduced when compared to those with IDA.

CONCLUSIONS

This study showed that the values of haematological parameters, especially haematocrit, Hb, MCV, MCH, MCHC and red blood cell distribution width (RDW), are lower in patients with IDA, especially when associated with α-thal and therefore it may be useful to discriminate between the different types of microcytic anaemia.

RBC Distribution Width: Biomarker for Red Cell Dysfunction and Critical Illness Outcome?

OBJECTIVES

RBC distribution width is reported to be an independent predictor of outcome in adults with a variety of conditions. We sought to determine if RBC distribution width is associated with morbidity or mortality in critically ill children.

DESIGN

Retrospective observational study.

SETTING

Tertiary PICU.

PATIENTS

All admissions to St. Louis Children's Hospital PICU between January 1, 2005, and December 31, 2012.

INTERVENTIONS

We collected demographics, laboratory values, hospitalization characteristics, and outcomes. We calculated the relative change in RBC distribution width from admission RBC distribution width to the highest RBC distribution width during the first 7 days of hospitalization. Our primary outcome was ICU mortality or use of extracorporeal membrane oxygenation as a composite. Secondary outcomes were ICU- and ventilator-free days.

MEASUREMENTS AND MAIN RESULTS

We identified 3,913 eligible subjects with an estimated mortality (by Pediatric Index of Mortality 2) of 2.94% ± 9.25% and an actual ICU mortality of 2.91%. For the study cohort, admission RBC distribution width was 14.12% ± 1.89% and relative change in RBC distribution width was 2.63% ± 6.23%. On univariate analysis, both admission RBC distribution width and relative change in RBC distribution width correlated with mortality or the use of extracorporeal membrane oxygenation (odds ratio, 1.19 [95% CI, 1.12-1.27] and odds ratio, 1.06 [95% CI, 1.04-1.08], respectively; p < 0.001). After adjusting for confounding variables, including severity of illness, both admission RBC distribution width (odds ratio, 1.13; 95% CI, 1.03-1.24) and relative change in RBC distribution width (odds ratio, 1.04; 95% CI, 1.01-1.07) remained independently associated with ICU mortality or the use of extracorporeal membrane oxygenation. Admission RBC distribution width and relative change in RBC distribution width both weakly correlated with fewer ICU- (r = 0.038) and ventilator-free days (r = 0.05) (p < 0.001).

CONCLUSIONS

Independent of illness severity in critically ill children, admission RBC distribution width is associated with ICU mortality and morbidity. These data suggest that RBC distribution width may be a biomarker for RBC injury that is of sufficient magnitude to influence critical illness outcome, possibly via oxygen delivery impairment.

Readmission for neonatal hyperbilirubinemia in an area with a high prevalence of glucose-6-phosphate dehydrogenase deficiency: A hospital-based retrospective study

BACKGROUND

Hyperbilirubinemia is one of the most common causes of neonatal readmission to hospital.

AIMS

To assess risk factors for hyperbilirubinemia among neonates readmitted for this condition and the ratio of the mean corpuscular hemoglobin concentration (MCHC) to the mean corpuscular volume (MCV).

METHODS

We retrospectively studied the clinical and laboratory findings, management and possible risk factors for hyperbilirubinemia in 301 neonates born at ≥35 weeks gestation and readmitted to hospital owing to hyperbilirubinemia over five years.

RESULTS

No risk factors for hyperbilirubinemia were identified in 64 (21.3%) neonates, and one or more risk factors were found in 237 neonates (78.7%). The most prevalent risk factor (41.9%) was G6PD deficiency, which occurred in 11 of the 15 neonates with a serum bilirubin level ≥427 μmol/l. A double-volume exchange blood transfusion was performed in two neonate boys in whom G6PD deficiency was the single risk factor for hyperbilirubinemia. One of them developed kernicterus later. The MCHC/MCV ratio of neonates with idiopathic hyperbilirubinemia, unexplained hemolysis, or other risk factors overlapped.

CONCLUSIONS

This study confirmed that in an area where G6PD deficiency is prevalent, it is the most common and most severe risk factor for hyperbilirubinemia. This finding supports routine neonatal screening for G6PD deficiency in such areas. The usefulness of determining the MCHC/MCV ratio in the management of hyperbilirubinemia is uncertain.

Importance of Mean Red Cell Distribution Width in Hypertensive Patients

PURPOSE

Red cell distribution width (RDW), expressed in femtoliters (fl), is a measure of the variation in the size of circulating erythrocytes and is often expressed as a direct measurement of the width of the distribution. We aim to observe the mean value of red cell distribution width (RDW) in hypertensive patients. Increased RDW can be used as a tool for early diagnosis, as an inflammatory marker, and a mortality indicator in hypertensive patients due to its close relation to inflammation.

MATERIALS AND METHODOLOGY

Hypertensive patients who had the condition for more than one year duration, diagnosed according to the Joint National Committee (JNC 7) criteria were subjected to complete blood count and RDW measurement. One hundred patients, aged between 12 years and 65 years were enrolled from the outpatient department of medicine at the Military Hospital Rawalpindi.

RESULTS

The mean age (± SD) of the patients was 51.48 ± 10.08 years. Out of 100 patients 69% were males whereas 31% were females. The overall frequency of hypertension more than five years was 55% subjects whereas 45% individuals had duration of hypertension less than five years. Mean RDW in females was found to be 49.35±8.42 fl while mean RDW in males was 44.78±7.11 fl. An independent sample t-test was applied to assess if there was any significant difference between age and gender. No significant difference between age and gender was found (p<0.05). The Mann-Whitney test was used to assess any association of RDW with gender. RDW values in females was found to be statistically significantly higher than in males (U=603, p=0.01). Linear regression showed that mean RDW value increased with increasing age (P <0.001).

CONCLUSIONS

A significant number of patients with hypertension have increased levels of RDW. Therefore, it is recommended that serum RDW should be checked regularly in patients with hypertension.

The association of hematologic inflammatory markers with atherogenic index in type 2 diabetic retinopathy patients

Background

Atherogenic dyslipidemia is particularly common in people with type 2 diabetes (DM2). Platelets from patients with DM2 have increased reactivity and baseline activation. The aim of the present study is to evaluate the relationship between atherogenic index and hematologic inflammatory markers and to evaluate the relationship between these parameters and associated variables in diabetic retinopathy (DR) patients.

Methods

The medical records of all patients admitted to the eye clinic between January and December 2014 were evaluated systematically. Laboratory parameters of 278 outpatients with DM2 diagnosed after the age of 30 years and 107 healthy subjects were analyzed.

Results

The DM2 + DR group consisted of 120 patients (47 males and 73 females; mean age 59.8±9.2 years). The DM2 without DR group consisted of 158 patients (59 males and 99 females; mean age 57.3±12.2 years). Mean platelet volume, platelet distribution width (PDW), platelet–lymphocyte (P/L) ratio, triglycerides, and atherogenic index were higher in DM2 patients than in control patients, but there was no difference between the DM2 + DR and the DM2 without DR groups. Only P/L ratio was different in the DM2 + DR patients compared to the DM2 without DR patients. Hemoglobin A1c levels correlated very weakly with the mean platelet volume, PDW, P/L ratio, and the red cell distribution width. The atherogenic index was very weakly correlated with the P/L ratio, PDW, and red cell distribution width.

Conclusion

Dyslipidemia-induced inflammation contributes to pathological processes that lead to retinopathy in DR patients.

Association between the Red Cell Distribution Width and Vasospastic Angina in Korean Patients

PURPOSE

The association between the red cell distribution width (RDW) and vasospastic angina (VSA) has not been elucidated. We investigated the association of the RDW with the incidence and angiographic subtypes of VSA in Korean patients.

MATERIALS AND METHODS

A total of 460 patients who underwent intracoronary ergonovine provocation tests were consecutively enrolled and classified into two groups: the VSA group (n=147, 32.0%) and non-VSA group (n=313, 68.0%). The subjects were classified into 3 subgroups (tertiles) according to the baseline level of RDW assessed before the angiographic provocation test.

RESULTS

The VSA group had a higher RDW than the non-VSA group (12.9±0.8% vs. 12.5±0.7%, p=0.013). The high RDW level demonstrated an independent association with the high incidence of VSA [second tertile: hazard ratio (HR) 1.96 (1.13-2.83), third tertile: HR 2.33 (1.22-3.47), all p<0.001]. Moreover, the highest RDW tertile level had a significant association with the prevalence of the mixed-type coronary spasm [HR 1.29 (1.03-1.59), p=0.037].

CONCLUSION

The high level of RDW was significantly associated with the prevalence of VSA and the high-risk angiographic subtype of coronary spasm, suggesting that a proactive clinical investigation for VSA could be valuable in Korean patients with an elevated RDW.

Folate supplementation in people with sickle cell disease

BACKGROUND

Sickle cell disease is a group of disorders that affects haemoglobin, which causes distorted sickle- or crescent-shaped red blood cells. It is characterized by anaemia, increased susceptibility to infections and episodes of pain. The disease is acquired by inheriting abnormal genes from both parents, the combination giving rise to different forms of the disease. Due to increased erythropoiesis in people with sickle cell disease, it is hypothesized that they are at an increased risk for folate deficiency. For this reason, children and adults with sickle cell disease, particularly those with sickle cell anaemia, commonly take 1 mg of folic acid orally every day on the premise that this will replace depleted folate stores and reduce the symptoms of anaemia. It is thus important to evaluate the role of folate supplementation in treating sickle cell disease.

OBJECTIVES

To analyse the efficacy and possible adverse effects of folate supplementation (folate occurring naturally in foods, provided as fortified foods or additional supplements such as tablets) in people with sickle cell disease.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings. We also conducted additional searches in both electronic databases and clinical trial registries.Date of last search: 07 December 2015.

SELECTION CRITERIA

Randomised, placebo-controlled trials of folate supplementation for sickle cell disease.

DATA COLLECTION AND ANALYSIS

Four review authors assessed the eligibility and risk of bias of the included trials and extracted and analysed the data included in the review. We used the standard Cochrane-defined methodological procedures.

MAIN RESULTS

One trial, undertaken in 1983, was eligible for inclusion in the review. This was a double-blind placebo-controlled quasi-randomised triaI of supplementation of folic acid in people with sickle cell disease. A total of 117 children with homozygous sickle cell (SS) disease aged six months to four years of age participated over a one-year period (analysis was restricted to 115 children).Serum folate measures, obtained after trial entry at six and 12 months, were available in 80 of 115 (70%) participants. There were significant differences between the folic acid and placebo groups with regards to serum folate values above 18 µg/l and values below 5 µg/l. In the folic acid group, values above 18 µg/l were observed in 33 of 41 (81 %) compared to six of 39 (15%) participants in the placebo (calcium lactate) group. Additionally, there were no participants in the folic acid group with serum folate levels below 5 µg/l, whereas in the placebo group, 15 of 39 (39%) participants had levels below this threshold. Haematological indices were measured in 100 of 115 (87%) participants at baseline and at one year. After adjusting for sex and age group, the investigators reported no significant differences between the trial groups with regards to total haemoglobin concentrations, either at baseline or at one year. It is important to note that none of the raw data for the outcomes listed above were available for analysis.The proportions of participants who experienced certain clinical events were analysed in all 115 participants, for which raw data were available. There were no statistically significant differences noted; however, the trial was not powered to investigate differences between the folic acid and placebo groups with regards to: minor infections, risk ratio 0.99 (95% confidence interval 0.85 to 1.15); major infections, risk ratio 0.89 (95% confidence interval 0.47 to 1.66); dactylitis, risk ratio 0.67 (95% confidence interval 0.35 to 1.27); acute splenic sequestration, risk ratio 1.07 (95% confidence interval 0.44 to 2.57); or episodes of pain, risk ratio 1.16 (95% confidence interval 0.70 to 1.92). However, the investigators reported a higher proportion of repeat dactylitis episodes in the placebo group, with two or more attacks occurring in 10 of 56 participants compared to two of 59 in the folic acid group (P < 0.05).Growth, determined by height-for-age and weight-for-age, as well as height and growth velocity, was measured in 103 of the 115 participants (90%), for which raw data were not available. The investigators reported no significant differences in growth between the two groups.The trial had a high risk of bias with regards to random sequence generation and incomplete outcome data. There was an unclear risk of bias in relation to allocation concealment, outcome assessment, and selective reporting. Finally, There was a low risk of bias with regards to blinding of participants and personnel. Overall the quality of the evidence in the review was low.There were no trials identified for other eligible comparisons, namely: folate supplementation (fortified foods and physical supplementation with tablets) versus placebo; folate supplementation (naturally occurring in diet) versus placebo; folate supplementation (fortified foods and physical supplementation with tablets) versus folate supplementation (naturally occurring in diet).

AUTHORS' CONCLUSIONS

One doubIe-blind, placebo-controlled triaI on folic acid supplementation in children with sickle cell disease was included in the review. Overall, the trial presented mixed evidence on the review's outcomes. No trials in adults were identified. With the limited evidence provided, we conclude that, while it is possible that folic acid supplementation may increase serum folate levels, the effect of supplementation on anaemia and any symptoms of anaemia remains unclear.Further trials may add evidence regarding the efficacy of folate supplementation. Future trials should assess clinical outcomes such as folate concentration, haemoglobin concentration, adverse effects and benefits of the intervention, especially with regards to sickle cell disease-related morbidity. Trials should include people with sickle cell disease of all ages and both sexes, in any setting. To investigate the effects of folate supplementation, trials should recruit more participants and be of longer duration, with long-term follow up, than the trial currently included in this review.

Red Cell Distribution Width Can Predict the Significance of Angiographically Intermediate Coronary Lesions

OBJECTIVE

In the present study, the association between red cell distribution width (RDW) with functional significance of intermediate coronary artery lesions was investigated.

MATERIALS AND METHODS

Two hundred and forty-six consecutive patients, 168 males and 78 females, who underwent fractional flow reserve (FFR) measurement for angiographically intermediate coronary stenosis (40-70% in quantitative coronary analysis) in the left anterior descending coronary artery were enrolled into the study. The functional significance of intermediate coronary artery lesions was determined by FFR measurement. An FFR value <0.75 was defined as functionally significant. Venous blood samples were taken within 48 h before the FFR measurement, and RDW levels were determined by a Coulter LH Series hematology analyzer. Logistic regression analysis was used to examine the association between functional significance in FFR measurement and other variables.

RESULTS

Of the 246 patients, 62 (25.2%) exhibited significant functional stenosis (FFR <0.75) in the FFR measurement. The mean RDW level was significantly higher in patients with significant stenosis (14.19 ± 0.73 vs. 13.69 ± 0.77, p < 0.001). In stepwise multivariate logistic regression analysis, RDW (OR = 2.489, 95% CI = 1.631-3.799, p < 0.001) and male gender (OR = 2.826, 95% CI = 1.347-5.928, p = 0.006) were independent predictors of significant functional stenosis.

CONCLUSION

Increased RDW levels were associated with functional significance of angiographically intermediate coronary artery stenoses.

Red cell distribution width and carotid atherosclerosis progression. The Tromsø Study

Red cell distribution width (RDW), a measure of the size variability of circulating erythrocytes, is associated with cardiovascular morbidity and mortality. We aimed to investigate whether RDW was associated with progression of atherosclerotic plaques in subjects recruited from the general population. Baseline characteristics, including RDW, were collected from 4677 participants in the fourth survey of the Tromsø Study conducted in 1994/95. Prevalence of carotid plaques and total plaque area (TPA) were assessed by ultrasonographic imaging at baseline and after seven years of follow-up. Generalised linear models were used to analyse change in TPA across tertiles of RDW. Change in TPA was significantly higher across tertiles of RDW in crude analysis and in multivariable analysis adjusted for cardiovascular risk factors. The mean change in TPA increased from 5.6 mm² (4.9-6.4) in tertile 1 (RDW ≤ 12.6 %) to 6.7 mm² (5.9-7.6) in tertile 3 (RDW ≥ 13.3) in multivariable analysis adjusted for body mass index, total cholesterol, HDL cholesterol, systolic blood pressure, self-reported diabetes, smoking status, platelet count, white blood cell count, and hs-CRP levels (p for trend 0.003). A 1 % increase in RDW was associated with 0.6 mm² (0.1-1.2) increase in TPA in multivariable analysis (p=0.03). RDW was associated with progression of atherosclerosis after adjustments for traditional atherosclerotic risk factors. Our findings suggest that the link between RDW and cardiovascular morbidity and mortality may be explained by atherosclerosis.

Relation of red cell distribution width with CHA2DS2-VASc score in patients with nonvalvular atrial fibrillation

BACKGROUND

Red cell distribution width (RDW) has been shown to be helpful in predicting adverse long-term events in patients with cardiovascular diseases. However, to date, no study has been conducted on the relationship between RDW and thromboembolism risk in atrial fibrillation (AF). Therefore, we aimed to investigate the relationship between RDW and CHA2DS2-VASc score used for the evaluation of thromboembolism risk in patients with AF.

METHODS

The study population consisted of 320 patients with AF. We calculated CHA2DS2-VASc risk score for each patient and baseline hemoglobin, white blood cell, RDW, mean platelet volume, platelet counts, estimated glomerular filtration rate (eGFR), left ventricular ejection fraction (LVEF), and left atrial volume index (LAVi) were measured.

RESULTS

High CHA2DS2-VASc score group had higher RDW, lower LVEF, higher LAVi, and lower eGFR values when compared to the low CHA2DS2-VASc score group. The multivariate logistic regression analysis performed to predict high CHA2DS2-VASc scores revealed that RDW eGFR, LVEF, and LAVi were independent predictors. The area under the receiver-operating characteristic curve of RDW was 0.65 (0.59-0.71, P < .001) to predict high CHA2DS2-VASc score.

CONCLUSION

Our study results indicate that RDW values are significantly correlated with CHA2DS2-VASc score in nonanemic patients with AF, while also being independent predictor of high CHA2DS2-VASc score.

Accuracy of erythrogram and serum ferritin for the maternal anemia diagnosis (AMA): a phase 3 diagnostic study on prediction of the therapeutic responsiveness to oral iron in pregnancy

BACKGROUND

Pregnancy anemia remains as a public health problem, since the official reports in the 70's. To guide the treatment of iron-deficiency anemia in pregnancy, the haemoglobin concentration is the most used test in spite of its low accuracy, and serum ferritin is the most reliable test, although its cutoff point remains an issue.

METHODS/DESIGN

The aim of this protocol is to verify the accuracy of erythrocyte indices and serum ferritin (studied tests) for the diagnosis of functional iron-deficiency in pregnancy using the iron-therapy responsiveness as the gold-standard. This is an ongoing phase III accuracy study initiated in August 2011 and to be concluded in April 2013. The subjects are anemic pregnant women (haemoglobin concentration < 11.0 g/dL) attended at a low-risk prenatal care center in the Northeast of Brazil. The sample size (n 278) was calculated to estimate sensitivity of 90% and 80% of specificity with relative error of 10% and power of 95%. This study has a prospective design with a before-after intervention of 80 mg of daily oral iron during 90 days and will be analyzed as a delayed-type cross-sectional study. Women at the second trimester of pregnancy are being evaluated with clinical and laboratorial examinations at the enrollment and monthly. The 'responsiveness to therapeutic test with oral iron' (gold-standard) was defined to an increase of at least 0.55 Z-score in haemoglobin after 4 weeks of treatment and a total dose of 1200 mg of iron. At the study conclusion, sensitivities, specificities, predictive values, likelihood ratios and areas under the ROC (Receiver Operating Characteristic) curves of serum ferritin and erythrocyte indices (red blood cell count, haematocrit, haemoglobin concentration, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, red blood cell distribution width, reticulocyte count) will be tested. The compliance and adverse effects are considered confounding variables, since they are the main obstacles for the iron-therapy responsiveness.

DISCUSSION

This study protocol shows a new approach on iron-deficiency anemia in pregnancy from a functional point of view that could bring some insights about the diagnostic misclassifications arising from the dynamic physiologic changes during the gestational cycle.

TRIAL REGISTRATION

WHO International Clinical Trials Registry Platform U1111-1123-2605.

Similar hematological and biochemical parameters among periodontitis and control group subjects

OBJECTIVE

There are conflicting reports in the past literature documenting the tendency of anemia in patients with periodontitis. Hence, this study was undertaken to assess whether periodontitis may cause an anemic state, by evaluating and comparing the red blood cell count, levels of hemoglobin, hematocrit, erythrocyte sedimentation rate (ESR), serum iron and serum ferritin between subjects with and without periodontitis.

METHODS

In this cross-sectional study, 140 systemically healthy subjects of both sexes (mean age 46 years) were recruited as control group (50 subjects without periodontitis) and study groups comprising 30 patients each with mild, moderate and severe chronic generalized periodontitis. Periodontal parameters and orthopantamographs were taken for all the groups and then 5 mL venous blood samples were sent for complete blood count and biochemical analysis. Inter-group and intra-group comparisons were performed for all the assessed parameters.

RESULTS

The periodontal parameters were significantly higher (P⩽.05) in periodontitis patients. Except for the ESR, which was significantly higher (P=.03) in the mild periodontitis group than the control group, hematological and biochemical parameters were not significantly different (P>.05) among the study groups or between the control and study groups. This difference was not evident even among the male and female subjects of both control and study groups (P>.05).

CONCLUSIONS

Within the limits of this cross-sectional study, it can be concluded that the presence and severity of periodontitis may not affect the hematological and biochemical parameters of an individual. Further long term studies are however encouraged to validate these findings.