Establishing local reference intervals for full blood count and white blood cell differential counts in Cape Town, South Africa.

BACKGROUND: Accurate laboratory reference intervals (RIs) are essential to differentiate between health and disease. There are variations in haematological indices within populations relating to gender, age, ethnicity and environment. Iron deficiency is common, has a wide range of clinical morbidities and affects red cell indices. Locally derived RIs for full blood count (FBC) parameters are needed for the Western Cape region of South Africa, after the exclusion of iron deficiency. In addition, information regarding the prevalence of iron deficiency in first-time blood donors would inform blood transfusion services regarding policies to screen for and treat iron deficiency. OBJECTIVES: To establish locally derived RIs for FBC and white blood cell (WBC) differential count parameters in healthy adults in the Cape Town area, by including first-time blood donors and excluding those with iron deficiency and thalassaemic indices. These new locally established RIs could update those in use by the local National Health Laboratory Service. A secondary objective was to establish the prevalence of iron deficiency in first-time blood donors. This would inform blood donation policies regarding screening and appropriate iron supplementation in high-risk groups prior to blood donation. METHODS: This was a prospective, descriptive study with direct convenience sampling. Participants were prospective voluntary blood donors aged between 18 and 60 years, presenting for first-time blood donation. Ethnicity was self-identified. Participants who tested positive for HIV or hepatitis B and/or C viruses were excluded. Prospective participants with iron deficiency, defined by serum ferritin levels below the RI, and those with red cell indices suggestive of an underlying thalassaemia trait were excluded. FBC samples were analysed using a Sysmex XN-1000 cell counter. Statistical non-parametric methods were used to calculate the RIs, according to international guidelines. RESULTS: Of the 774 participants screened, 82 (11%) had iron deficiency and were excluded. Six hundred and sixty-two patients were included for analysis, 409 (62%) female and 253 (38%) male. The majority of the participants, 348 (53%), were between 20 and 29 years of age, with a mean age of 29 years for females and 28 years for males. Participants comprised a mix of the various ethnic groups residing in Western Cape Province. The mean haemoglobin concentration for females was lower than that for males (p<0.0001). There were significant gender differences for total WBC count, absolute neutrophil count and platelet count, with females having higher counts than males. CONCLUSIONS: Locally established, population-specific RIs are essential for the accurate interpretation of haematological indices. This study established locally derived gender-specific RIs for the Cape Town region, after exclusion of iron deficiency. These new RIs have implications for the accurate diagnoses of cytopenias, cytoses and other blood count abnormalities. Iron deficiency is common in first-time blood donors, and screening for iron deficiency using point-of-care testing should be considered.

An evaluation of existing manual blood film schistocyte quantitation guidelines and a new proposed method.

Schistocytosis is the morphological hallmark of the microangiopathic haemolytic anaemia of thrombotic microangiopathy (TMA). Consensus guidelines for manual schistocyte quantitation are available, but limited research has evaluated them. The 2012 International Council for Standardization in Haematology (ICSH) recommends a schistocyte quantitation of 1% as a robust cut-off for significance, with the quantitation including helmet, crescent, triangle and keratocyte poikilocytes; and microspherocytes only in the presence of helmets, crescents/triangles, and keratocytes. We aimed to evaluate the relative contribution of these different poikilocytes to schistocyte counting; compare the ICSH method with our proposed method which counts only cells most specific for red cell fragmentation (helmet, crescent and triangular schistocytes); and evaluate inter- and intra-observer agreement. Blood films were sourced from the Australian Snakebite Project, including non-envenomed and envenomed cases, with and without TMA. In blood films across the range of schistocytosis, the predominant poikilocytes present were helmets and crescents. Triangles, keratocytes and microspherocytes were typically only present when ICSH schistocyte count was >1%. With results dichotomised as <1.0% or ≥1.0%, our proposed new method versus the ICSH method showed almost perfect agreement [observed agreement 95%, Cohen's kappa (κ)=0.84, SE 0.04, 95% CI 0.76-0.92, p<0.005]. Inter-observer strength of agreement for our method was moderate (Fleiss' κ for comparisons between three non-unique microscopists κ=0.50, SE 0.05, 95% CI 0.41-0.59, p<0.005). Intra-observer reproducibility assessed in two microscopists ranged from substantial (Cohen's κ=0.71, SE 0.08, 95% CI 0.55-0.86, p<0.005) to borderline almost perfect agreement (Cohen's κ=0.81, SE 0.07, 95% CI 0.68-0.93, p<0.005). Schistocyte quantitation using our new method is simpler than the 2012 ICSH method and had almost perfect agreement. Our finding of moderate inter-observer agreement in quantitating helmet, triangle and crescent schistocytes is applicable to both the ICSH and our newly proposed method. This finding underscores the importance of clinicopathological correlation and repeated examinations in the context of a clinically suspected TMA.

The results of external quality assessment programme on urine leukocyte and erythrocyte counting in Poland.

INTRODUCTION: Urine particle analysis is an important diagnostic tool. The aim of this study was to evaluate the quality of urine leukocyte (WBC) and erythrocyte (RBC) counting results obtained with manual and automated methods in Polish laboratories participating in the international external quality assessment (EQA) programme. MATERIALS AND METHODS: 1400 WBC and RBC counting results were obtained from 183 laboratories in EQA surveys organised by Labquality (Helsinki, Finland) from 2017 to 2019. The between-laboratory coefficient of variation (CV), the percentage difference between the laboratories' results and target values (Q-score (%)), as well as modified Youden plots were analysed. RESULTS: For automated method groups, the medians of inter-laboratory CVs varied from 14% to 33% for WBC counting and from 10% to 39% for RBC counting. For manual method groups, the medians of CV varied from 53% to 71% (WBC) and from 55% to 70% (RBC), and they were significantly higher, in comparison to CVs for most automated method groups (P < 0.001). The highest percentage of results outside the target limits (36%) and the highest range of Q-score (%) (from - 93% to 706%) were observed for laboratories which participated in the surveys for the first or second time. The percentage of deviating results and the ranges of Q-score decreased with an increased frequency of laboratories' participation in the surveys. CONCLUSIONS: The quality of manual methods of urine WBC and RBC counting is unsatisfactory. There is an urgent need to take actions to improve laboratories' performance and to increase harmonisation of the results.

Development of a flow standard to enable highly reproducible measurements of deformability of stored red blood cells in a microfluidic device.

BACKGROUND: Great deformability allows red blood cells (RBCs) to flow through narrow capillaries in tissues. A number of microfluidic devices with capillary-like microchannels have been developed to monitor storage-related impairment of RBC deformability during blood banking operations. This proof-of-concept study describes a new method to standardize and improve reproducibility of the RBC deformability measurements using one of these devices. STUDY DESIGN AND METHODS: The rate of RBC flow through the microfluidic capillary network of the microvascular analyzer (MVA) device made of polydimethylsiloxane was measured to assess RBC deformability. A suspension of microbeads in a solution of glycerol in phosphate-buffered saline was developed to be used as an internal flow rate reference alongside RBC samples in the same device. RBC deformability and other in vitro quality markers were assessed weekly in six leukoreduced RBC concentrates (RCCs) dispersed in saline-adenine-glucose-mannitol additive solution and stored over 42 days at 4°C. RESULTS: The use of flow reference reduced device-to-device measurement variability from 10% to 2%. Repeated-measure analysis using the generalized estimating equation (GEE) method showed a significant monotonic decrease in relative RBC flow rate with storage from Week 0. By the end of storage, relative RBC flow rate decreased by 22 ± 6% on average. CONCLUSIONS: The suspension of microbeads was successfully used as a flow reference to increase reproducibility of RBC deformability measurements using the MVA. Deformability results suggest an early and late aging phase for stored RCCs, with significant decreases between successive weeks suggesting a highly sensitive measurement method.

Study of the analytical performance at different concentrations of hematological parameters using Spanish EQAS data.

Background External quality assessment programs are one of the currently available tools to evaluate the analytical performance of clinical laboratories, where the measurement error (ME) obtained can be compared with quality specifications to evaluate possible deviations. The objective of this work was to analyze the ME behavior over the analytical range to assess the need to establish concentration-dependent specifications. Methods A total of 389,000 results from 585 laboratories and 2628 analyzers were collected from the Spanish external quality assessment schemes (EQAS) in hematology during the years 2015-2016. The parameters evaluated included white blood cells, red blood cells, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets, prothrombin time, activated partial thromboplastin time, neutrophils, lymphocytes, monocytes, eosinophils, basophils, reticulocytes, hemoglobin A2, antithrombin, factor VIII, protein C and von Willebrand factor. The 90th percentile of ME was calculated for every concentration evaluated of each parameter. Results We found a significant variation in the analytical performance of leukocytes, platelets, neutrophils, lymphocytes, monocytes, eosinophils, basophils, prothrombin time, reticulocytes, hemoglobin A2, antithrombin and protein C. Furthermore, this ME variation may not allow complying with the same biological variability requirements within the whole analytical range studied. Conclusions Our work shows the importance of implementing concentration-dependent specifications which can help laboratories to use proper criteria for quality specifications selection and for a better external quality control results evaluation.

Full blood count and white cell differential count reference ranges obtained from a healthy urban South African population residing in the Western Cape of South Africa.

BACKGROUND: Research has suggested that individuals of African descent have lower white cell and neutrophil counts than Caucasians. These differences could lead to incorrect clinical decisions, and therefore, ethnic-specific reference ranges are required. The Western Cape region of South Africa is uniquely diverse, comprising Caucasian, Mixed Ancestry and those of African descent. The aim of this study was to compare the full blood count and differential counts across the three major ethnic groups residing in this area and to propose appropriate RIs. METHODS: The study formed part of the international project led by the Committee on Reference Intervals and Decision Limits (C-RIDL), and therefore, the strict guidelines laid out by the committee were followed. Full blood count and differential counts were performed on a Beckman Coulter ACT 5 diff AL analyser within 2-4 hours of collection and were reported as mean (standard deviation), 2.5th and 97.5th percentiles. Comparisons were analysed using Spss v25 and Statistica v13, and a P value of < 0.05 was considered significant. RESULTS: Reference ranges for Caucasian and Mixed Ancestry individuals were similar while white cell (P = 0.016), monocyte (P < 0.001), neutrophil (P = 0.034) and red cell indices were significantly different amongst the three population groups. There were however no statistical and clinical significant differences between the eosinophil, lymphocyte, red cell and platelet counts across the three groups. CONCLUSION: In conclusion, subjects of Mixed Ancestry, in this region, have similar reference intervals to those of European descent, while lower white cell and neutrophil counts in Africans have been confirmed.

Hematologic and serum biochemical reference intervals for wild eastern quolls (Dasyurus viverrinus): Variation by age, sex, and season.

BACKGROUND: The eastern quoll (Dasyurus viverrinus) is an endangered carnivorous marsupial that has recently suffered significant population declines. Several small captive breeding populations have been established, with plans to translocate wild and captive individuals to areas of their former distribution. Accordingly, hematologic and serum biochemical reference intervals (RIs) established from wild eastern quoll populations are essential for monitoring the health and disease status of both captive and wild populations, and to evaluate the health of individuals before, during, and after translocation. OBJECTIVES: We aimed to establish hematologic and serum biochemical RIs for wild eastern quolls, and examine the effects of age, sex, and season. METHODS: We collected a total of 202 hematologic samples, 309 packed cell volume samples, and 335 serum biochemical samples from 168 individual quolls between May 2011 and November 2013. Species-level RIs were established, as well as RIs of groups separated by age (juvenile, adult) and sex (adult male, adult female) using nonparametric, robust, and parametric methods. Seasonal variation in age- and sex-specific reference values was also assessed. RESULTS: Strong age and seasonal variation were evident in many hematologic and serum biochemical analytes, with significant variation observed in serum biochemical analytes between the sexes. CONCLUSIONS: The observed age, sex, and seasonal variation reflect differences in the timing of growth and reproductive stressors, which interact with seasonal energetic demands. Our findings highlight the importance of using age-, sex-, and season-specific RIs for clinical evaluation of eastern quolls, as species-level RIs will inadvertently smooth and mask important seasonal fluctuations that reflect reproductive status at different times.

Effect of age, sex, and season on the variation in blood analytes of a clinically normal ex situ population of killer whales (Orcinus orca).

BACKGROUND: The effects of sex, age, and season on blood analyte concentrations have not been investigated for the killer whale (Orcinus orca). Defining these changes provides background data for improving the care of managed populations and defines normal changes that could occur in wild counterparts. OBJECTIVES: We aimed to define hematologic and serum biochemical variation by age, sex, and season for an ex situ killer whale population. METHODS: Blood samples collected from killer whales during normal wellness exams were retrospectively identified. Killer whales were categorized by age; calf (0-2.9 years), juvenile (3-10.9 years), early adult (11-20.9 years), adult (21-30.9 years), and aged (>30.9 years); sex; and season. Standard CBC and biochemistry were collated, and only samples without evidence of disease were used. A mixed effects maximum likelihood regression with animal identification (ID) as the random effects variable was used to compare groups with a significance set at P ≤ 0.01. RESULTS: All analytes differed by age, while only four differed by sex. Red blood cell parameters and associated renal analytes increased with age, while liver-associated analytes and glucose decreased. Season affected 59% of the blood analytes. CONCLUSIONS: Aged killer whales showed strong evidence of altered physiology as compared with younger animals. Anemia did not develop with age as was observed in one bottlenose dolphin population. Observed decreases in renal function could be caused by chronic disease or dehydration. Decreases in immune function parameters suggest immune senescence. These results provide background data for evaluating the health of managed and free-ranging killer whales.

Comparison of automated devices UX-2000 and SediMAX/AutionMax for urine samples screening: A multicenter Spanish study.

OBJECTIVES: In this study we aim to compare UX2000 (Sysmex Corp, Japan) and SediMAX/AutionMax (Arkray Factory Inc., Japan), totally automatized analyzers, against Fuchs-Rosenthal counting chamber, the gold standard technique for sediment analysis. DESIGN AND METHODS: Urine samples of 1454 patients from three Spanish hospitals were assessed for red and white blood cells (RBC; WBC) using three different techniques: flow cytometry, image-based method and Fuchs-Rosenthal counting chamber. Test strip results were subjected to concordance evaluation. Agreement was assessed by Cohen's weighted kappa for multinomial results. Sensitivity (SE) and specificity (SP) were calculated. RESULTS: The categorization of the results showed that UX-2000 had higher concordance over SediMAX for WBC (0.819 vs. 0.546) and similar for RBC (0.573 vs. 0.630). For RBC, UX-2000 had higher SE (92.7% vs. 80.3%) but lower SP (77.1% vs. 87.4%), and showed higher both SE (94.3% vs. 76.7%) and SP (94.7% vs. 88.2%) for WBC. Inter-devices test strip agreement was substantial (kappa>0.600) for all variables except for bilirubin (kappa: 0.598). Intra-device test strip agreement was similar for UX2000 and SediMAX with regard to RBC (kappa: 0.553 vs. 0.482) but better for UX2000 with regard to WBC (0.688 vs. 0.465). CONCLUSIONS: Both analyzers studied are acceptable for daily routine lab work, even though SediMAX is easier to use in laboratories thanks to its lower maintenance procedure. UX-2000 has shown to have better concordance with the gold standard method. However, it needs some improvements such as an image module in order to decrease manual microscopy review for urine samples.

Reference values for nucleated red blood cells and serum lactate in very and extremely low birth weight infants in the first week of life.

STUDY PURPOSE: To provide reference values for nucleated red blood cells and serum lactate concentrations in very and extremely low birth weight (VLBW/ELBW) infants in the first week of life. PATIENTS AND METHODS: Retrospective data analysis of serial, daily measurements of NRBC counts and serum lactate during the first 6days of life in VLBW and ELBW infants. RESULTS: In total, 250 infants<1500g were included in this study. Intrauterine growth retardation (IUGR) was seen in 87 (34.8%) patients. Gestational age (GA) ranged from 23 to 35weeks (mean 29.0weeks) and birth weight (BW) was 320-1499g (mean 1047.9g). During hospital stay, 55 (22%) patients developed IVH and 55 children (22%) BPD. PVL was seen in 12 (4.8%) cases, ROP in 93 (37.2%) and NEC in only 1 (0.4%) patient. NRBC counts as well as serum lactate concentrations depended significantly on birth weight (p<0.01) and presence respectively absence of IUGR (p<0.01). Both NRBC counts and serum lactate concentrations declined constantly during the 6-day period (p<0.01), and both were highly inter-correlated (p<0.01). CONCLUSIONS: This is one of only a very few studies that systematically and serially evaluated both NRBC counts and serum lactate concentration in VLBW and ELBW infants in the first 6days of life. Both parameters were significantly dependent on birth weight and the presence of IUGR. Moreover, a significant correlation between NRBC counts and serum lactate concentrations in this early period of life could be demonstrated. In future studies, the role of these readily available biomarkers in predicting important neonatal outcome parameters needs to be evaluated in a prospective manner.

[The application of Hoffmann method in the establishment of children's reference intervals of erythrocyte count].

OBJECTIVE: To verify the reliability and feasibility of Hoffmann method in establishing pediatric reference intervals (RI) of erythrocyte count. METHODS: Three hundreds and ninty-two thousands of hospital-based data for erythrocyte count of children aged in 1 to 17, measured by the Sysmex Xs-800i, was collected from Beijing Children's Hospital during January to December 2014. Outliers were removed using the Dixon method, then Hoffmann method was conducted to establish the gender and age stratified pediatric RIs of erythrocyte count. The erythrocyte count of 2 217 healthy children, recruited from Beijing Children's Hospital and Liaocheng Children's Hospital in Shandong province, was conducted as normal reference to verify the reliability of Hoffmann method in establishing RIs and to compare with existing RIs. RESULTS: In 4 subgroups as following, male aging 1 to 12 years, male aging 13 to 17 years, female aging 1 to 12 years, female aging 13 to 17 years, the RIs of erythrocyte count established using Hoffmann method were (4.1-5.4)×10(12)/L, (4.4-5.7)×10(12)/L, (4.0-5.3)×10(12)/L, (4.0-5.3)×10(12)/L, respectively. The verification results in 2 217 healthy children showed that the proportions of out of range in four subgroups were 6.17%, 8.81%, 6.22%, 7.78%, respectively. CONCLUSION: Hoffmann method produce reliable RIs according with the actual situation in healthy children, which is also convenient and is worth popularizing in clinical practice.

Investigation and Analysis of Reference Intervals for Blood Cell Parameters in a Healthy Population from Daxingan Region Inner Mongolia.

BACKGROUND: Blood cell parameters in a healthy population of different ages and genders from the Daxingan region of Inner Mongolia were evaluated to establish reference intervals (RIs) for venous blood parameters for healthy individuals from this region. METHODS: Venous blood specimens were collected from 1757 healthy individuals aged 7-65 years and analyzed by an XE-5000 automated hematology analyzer. Results were statistically analyzed by gender and age group. RIs for venous blood parameters of children were compared to the National Clinical Laboratory Procedures and those of adults were compared to the Health Industry Standards of the People's Republic of China (WST405-2012). RESULTS: In the Daxingan region, WBC, RBC, MCV, and NEUT%, MONO%, and EO% of healthy children were significantly different between genders (p < 0.05). Other parameters were not significantly different (p > 0.05). All parameters of adults were significantly different between different genders (p < 0.05) except for LYMPH% and BASO%. Comparison of mean values between children and adults of the same gender revealed significant differences in each blood cell parameter (p < 0.05). RBC, MCV, MCH, MCHC, PLT, MONO%, and BASO% of adult men were significantly different between different age groups (p < 0.05), and HGB, HCT, and EO% of adult women were significantly different between different age groups (p < 0.05). For children, only the mean of MCHC and EO% were close to the National Clinical Laboratory Procedures. Mean of RBC, HGB, PLT, LYMPH%, and MONO% were higher and the remaining parameters were lower than the National Clinical Laboratory Procedures. Compared with WST405-2012 for adults, PLT of women aged 18-40 years and NEUT% of adults were higher, whereas the mean of EO% and BASO% were significantly lower. CONCLUSIONS: RIs for venous blood parameters change with age, geographic region, ethnic group, and gender. There is a great necessity to establish RIs for venous blood parameters among the healthy population in the Daxingan region.

Automated Nucleated RBC Measurement Using the Sysmex XE-5000 Hematology Analyzer: Frequency and Clinical Significance of the Nucleated RBCs.

OBJECTIVES: We validated the automatic nucleated RBC (nRBC) count on a Sysmex XE-5000 hematology analyzer (Sysmex Corporation, Kobe, Japan) and then evaluated the frequency of nRBCs in our patient population. METHODS: We correlated automated nRBC enumeration by the Sysmex XE-5000 hematology analyzer on 463 peripheral blood (PB) samples with the manual nRBC count. Results from 360,504 consecutive blood samples were reviewed to determine the frequency of nRBCs in various patient populations in our hospital. RESULTS: There was a strong correlation between the automated and manual nRBC count (Pearson's r = 0.97). Frequency of nRBCs varied in different patient populations and was significantly higher in the presence of other morphology flags or abnormal CBC parameters. Low-level nRBCs (0.2%-1.3%) were detected in 0.5% of samples with otherwise normal parameters. CONCLUSIONS: The automated method offers many advantages for high-throughput laboratories, including faster turnaround time, labor savings, and high reliability. Automated nRBC measurement allowed us to recognize a group of individuals who have low-level circulating nRBCs with otherwise normal CBC parameters. Nucleated RBC levels below 1.5% as detected by the automated count may be present in patients without increased erythropoiesis or a pathologic bone marrow process.

Fragmented red cells reference range for the Sysmex XN®-series of automated blood cell counters.

INTRODUCTION: Fragmented red cells (FRCs) are a new parameter determined automatically by the latest generation of blood cell counters. FRC counts may be of interest as they may reflect schistocyte counts measured on a stained peripheral blood smear observed under the microscope. However, FRC counts depend on the technical procedure used to detect them so that reference ranges are device dependent. The XN-9000® is one of the latest models from the Sysmex series of analysers. MATERIAL, METHODS AND RESULTS: We aimed to establish a reference range for FRCs based on 1366 normal patient samples. The mean ± SD was 0.14 ± 0.35% and the median was 0% (95% confidence interval of the mean: 0.12-0.16%). We observed that the percentage of red blood cells with <17 pg of haemoglobin content (Hypo-He) was correlated to an FRC increase and that flagged results relating to red blood cells, reticulocytes or platelets might have presented with artefactually increased FRCs. CONCLUSION: The FRCs reference range (healthy subjects) should be useful for laboratory staff for selecting which blood smears to check optically.

Evaluation of schistocyte analysis by a novel automated digital cell morphology application.

INTRODUCTION: The CellaVision Advanced Red Blood Cell (RBC) Software Application is a new software for advanced morphological analysis of RBC, which automatically performs a preliminary characterization and grouping of RBC into 21 morphological categories, including schistocytes. Upon automated classification, the software offers the possibility of reclassification of RBC by the operator. The aim of this study was to evaluate the schistocyte analysis by the CellaVision Advanced RBC Application. METHODS: Schistocyte counts were evaluated comparing the automated count on a CellaVision DM96, both before and after reclassification, with the reference manual microscopic method according to the ICSH criteria. Thirty-six samples of hospitalized patients and 40 samples of controls were analyzed. RESULTS: Within-run, between-run and between-observer coefficients of variation were lower when counted with the CellaVision compared to the manual microscopic count. The very high sensitivity but rather poor specificity implicates the need for reclassification by the operator, following automated analysis. After reclassification, method comparison studies revealed good agreement with the manual microscopic method, with however slightly higher values of schistocytes for the automated analysis. CONCLUSION: The CellaVision Advanced RBC Software Application provides a sensitive and reproducible measurement of schistocytes in peripheral blood, but still requires manual revision. Furthermore, it is an easy-to-use software and an excellent teaching tool that might contribute to standardization in the investigation of schistocyte-related conditions.

Reference values for reticulocyte parameters and hypochromic RBC in healthy children.

INTRODUCTION: New erythrocyte and reticulocyte parameters available on modern hematology analyzers have shown to be useful markers in children. However, pediatric method-specific reference ranges for these indices are sparse. We aim to establish pediatric reference values for reticulocyte parameters and hypochromic red blood cells in healthy children with the ADVIA 2120 hematology analyzer. METHODS: Prospective study of 311 healthy children aged from 6 months to 18 years old with normal hematological parameters. ADVIA 2120 hematology analyzer (Siemens Healthcare Diagnostics, Amadora, Portugal) was used for whole-blood hematological measures. The sample population was grouped according to age into three cohorts, and gender distribution was used for participants aged ≥12 years. RESULTS: Age- and gender-specific reference limits of reticulocyte hemoglobin content (CHr or Ret-He), difference between the reticulocyte and erythrocyte hemoglobin content (Delta-He), immature reticulocyte fraction (IRF) and percentage of hypochromic red blood cells (%Hypo) are provided. Delta-He, IRF and %Hypo showed statistically significant gender differences in the 12-17 years group. CHr presented no significant gender variation within all age groups (median 30.8 ± 1.7 pg). CONCLUSION: Establishing reliable pediatric reference intervals for these novel hematological parameters may offer valuable prospects for clinical practice and research in the pediatrics field.

Ruptured aneurysmal subarachnoid hemorrhage in the emergency department: Clinical outcome of patients having a lumbar puncture for red blood cell count, visual and spectrophotometric xanthochromia after a negative computed tomography.

OBJECTIVES: Over the last decade, computed tomography scanners have gained resolution and have become the standard of care in the investigation of neurologically intact patients suffering from acute headache. The added value of the combined assessment of red blood cells count, visual and spectrophotometric xanthochromia, to detect ruptured aneurysmal subarachnoid hemorrhage (ASAH) following a negative head computed tomography (NHCT) was studied. METHODS: The population consisted of all patients who had cerebrospinal fluid tested for spectrophotometric xanthochromia between 2003 and 2009 identified through the clinical-laboratory database and who met all the inclusion criteria: >14 years old, had an initial Glasgow Coma Score of 15, a non-traumatic acute headache with a suspected subarachnoid hemorrhage recorded in the initial ED differential diagnosis and an initial negative head CT scan. RESULTS: A total of 706 patients were included. LP identified 5 ASAH (prevalence: 0.7%). In these patients, LP parameters were as follows: high red blood cell count (from 1310 to 63,000×10(6)/L), positive visual xanthochromia in 4 out of 5 ASAH, and positive spectrophotometric xanthochromia in 5 out of 5 ASAH. All ASAH patients were neurologically intact after intervention. No deaths or missed ASAH were reported. Angiographies were performed on 127 patients (19.5%) of which 47 (34.1%) had positive xanthochromia (visual or spectrophotometric). CONCLUSIONS: Considering the low prevalence of ASAH following an NHCT, intense resources were utilized to identify all 5 ASAH. Lumbar puncture analyses combining red blood cell count, visual and spectrophotometric xanthochromia identified all ASAH, allowing intervention and a positive clinical outcome. Our data support 1) that LP identifies the presence of a ruptured ASAH after an NHCT and 2)` that a guide to define a subpopulation of patients who would benefit from a lumbar puncture after an NHCT would be desirable.

A survey of Australian haematology reference intervals.

This study was designed to create a snapshot of Australian haematology reference intervals (RIs) in use, in particular red cell parameters. We present an analysis of survey results conducted across Australian laboratories between November 2012 and January 2013.All Australian laboratories enrolled in the Royal College of Pathologists of Australasia Quality Assurance Program (RCPA QAP) were invited to participate in the December 2012 Survey Monkey survey, with a response from 85 laboratories (17%) received. The scope included laboratory demographics (location, size/throughput, and network), RIs in use for the full blood count and selected derived parameters, their frequency of revision, source and statistical approach for derivation. Further questions related to uncertainty of measurement, pregnancy values, paediatric/adult cut-off, haematology profiles reported and the use of extended parameters.There is more consistency with some upper and lower limits than others, and wide ranges for reported uncertainty of measurement (UM). There is no apparent consistency with RIs used for particular instruments and technologies. When laboratories change their RIs, most obtain them from a text book, paper or another laboratory and have difficulty in determining the source. If they do determine their own, most don't have a standard operating procedure and calculations are not consistent in terms of sample size and statistical methods used.We have presented evidence of the wide variations in RIs used in Australian laboratories and that arguably these do not differ significantly from each other. The paediatric age cut-off requires standardisation.