CALIPER Hematology Reference Standards (I)

Diagnostic value of hemoglobin concentration in identifying Meckel's diverticulum in pediatric lower gastrointestinal bleeding

PURPOSE

To assess the diagnostic performance of hemoglobin concentration for Meckel's diverticulum (MD) and evaluate if hemoglobin levels could be useful in the surgical decision-making process of children with lower gastrointestinal bleeding (LGIB).

METHODS

Retrospective cohort study of children with LGIB attending the emergency department between 2011 and 2021. Episodes of LGIB were divided into two groups: MeckD (MD diagnosed by surgery) and non-MeckD. Demographic and clinical variables were recorded. Comparisons between groups were made using the χ2 and the Mann-Whitney U tests. The diagnostic performance of hemoglobin for MD was studied using ROC curves.

RESULTS

Eight hundred and nineteen episodes of LGIB were considered. Blood samples were obtained in 233 cases (31 with MD). There were differences between MeckD and non-MeckD in hemoglobin concentration (8.7 vs. 12.6; U = 592; p < 0.01), hematochezia (83.9% vs. 50.5%; χ2 = 12.1; p < 0.01), absence of other symptoms (61.3% vs. 39.6%; χ2 = 5.2; p < 0.02) and blood transfusions (41.9% vs. 9.9%; χ2 = 74.8; p < 0.01). Hemoglobin levels ≤ 8.3 g/dL obtained a specificity ≥ 99.01% and a positive likelihood ratio ≥ 35.8 for MD. The area under the curve was 0.91 (95% CI 0.86-0.94).

CONCLUSION

Hemoglobin showed a good diagnostic performance for MD. Low hemoglobin levels could guide surgical indications in the management of children with LGIB.

Reference intervals for reticulocyte count and derived reticulocyte parameters in a cohort of healthy adults

INTRODUCTION

Reticulocyte count and novel derived parameters provide insight into the effectiveness of erythropoiesis and may be useful tools in the classification and diagnosis of anemias. However, there is no standardisation, so we consider it necessary that each laboratory evaluates the parameters according to its own methodology and instrumentation and establishes its own reference ranges. Our aim was to establish the reference intervals (RIs) of reticulocyte profile provided by the Beckman Coulter DxH 900 haematological autoanalyzer in our reference population.

METHODS

One hundred and seventy-five healthy adults (18 to 62 years) were included. Subjects were collected from the blood donation centre of the Hospital Clínico San Carlos (Madrid, Spain) upon informed consent. Whole blood was collected and assayed for 14 haematological parameters on the Beckman Coulter DxH 900 analyzer in the haematology laboratory of the Clinical Analysis Department. RIs were established as per Clinical and Laboratory Standards Institute EP28-A3c guidelines using three different statistical approaches.

RESULTS

RIs estimated using the non-parametric method and the Harrell-Davis bootstrap method were very similar. RIs estimated by the robust method were narrower. Gender partitioning was required for two haematological parameters (low haemoglobin density (LHD) and microcytic anaemia factor (MAF)). The rest of the parameters did not need to be partitioned according to Lahti's method.

CONCLUSION

RIs have been established for 14 hematologic parameters of the reticulocyte profile for the Beckman Coulter DxH 900 haematology analyzer using a healthy cohort of adult subjects.

Paediatric reference intervals for haematology parameters analysed on Sysmex XN-9000: a comparison of methods in the framework of indirect sampling

OBJECTIVES

To provide age- and sex-specific paediatric reference intervals (RIs) for 13 haematological parameters analysed on Sysmex XN-9000 and compare different methods for estimating RIs after indirect sampling.

METHODS

Via the Danish Laboratory Information System, we conducted a population-based study. We identified samples from children aged 0-18 years analysed at Aarhus University Hospital from 2019 to 2023, including samples from general practitioners only. Information about all parameters were available for all samples via linkage to the local laboratory middleware. Then, we applied two different methods. First, we excluded potential pathological samples by predefined criteria: if the child had other abnormal blood measurements at date of request, or had a blood sample of any type analysed in the period two months before to two months after. We estimated RIs stratified by age- and sex using the non-parametric percentile method. Second, we used refineR (an open source automated algorithm) to exclude pathological samples and for RI estimation. Finally, we compared our data to results from a study using the direct method.

RESULTS

We identified 22,786 samples. After exclusion by predefined criteria, the population comprised 10,199 samples from 8,736 children (57 % of samples were from females and median age was 13 years). We estimated RIs for red blood cell, white blood cell and platelet indices. The two different methods showed agreement. Furthermore, our data provided results comparable to direct sampling.

CONCLUSIONS

Our study provided age- and sex-specific paediatric RIs for 13 haematology parameters useful for laboratories worldwide. RIs were robust using different methods in the framework of indirect sampling. Finally, our data showed agreement with the direct method, indicating that indirect sampling could be useful for establishing RIs on haematology parameters in the future.

Sex- and age-based reference intervals for capillary complete blood count parameters among urban preschoolers in southeast China based on a large community population

Background and aim

Pediatricians commonly use the complete blood count (CBC) of capillary blood to evaluate health status, guide diagnoses, and determine treatment strategies. This study aimed to establish sex- and age-specific reference intervals (RIs) for 23 capillary CBC parameters for urban preschoolers in Fuzhou, Southeast China.

Materials and methods

Capillary blood CBC data of 18,369 healthy preschoolers who underwent annual physical examinations at Fujian Maternity and Child Health Hospital between January 01, 2022, and November 31, 2023, were analyzed retrospectively. To fully validate the new RIs, the data of all apparently healthy children within the same age cohort at the same institution were comprehensively analyzed in December 2023. The new RIs were assessed by comparing them with the RIs currently used in laboratories and those obtained from different regions, sample types, or methodologies.

Results

Dynamic temporal changes that differ between males and females were observed in the blood system of 3-7-year-old children in this region. The new sex- and age-specific RIs for capillary CBC parameters were feasible to guide clinical decision-making in the local region.

Conclusions

Our findings demonstrated the importance of establishing sex- and age-specific RIs for each region and underscored the necessity of continuous adjustment of clinical Rls based on statistical rules and clinical responses.

Use of hospital big data to optimize and personalize laboratory test interpretation with an application

BACKGROUND AND AIMS

In laboratory medicine, test results are generally interpreted with 95% reference intervals but correlations between laboratory tests are usually ignored. We aimed to use hospital big data to optimize and personalize laboratory data interpretation, focusing on platelet count.

MATERIAL AND METHODS

Laboratory tests were extracted from the hospital database and exploited by an algorithmic stepwise procedure. For any given laboratory test Y, an "optimized and personalized reference population" was defined by keeping only patients whose laboratory values for all Y-correlated tests fell within their own usual reference intervals, and by partitioning groups by individual-specific variables like sex and age category. The method was applied to platelet count.

RESULTS

Laboratory data were recorded for 28,082 individuals. At the end of the algorithmic process, seven correlated laboratory tests were chosen, resulting in a reference sample of 159 platelet counts. A new 95 % reference interval was constructed [152-334 × 109/L], notably reduced (27.2 %) compared to conventional reference values [150-400 × 109/L]. The reference interval was validated on a sample of 2,129 patients from another downtown laboratory, emphasizing the potential transference of the hospital-derived reference limits.

CONCLUSION

This method offers new perspectives in laboratory data interpretation, especially in patient screening and longitudinal follow-up.

Increased MCHC*RDW-SD interaction values: indicators of neurological impairment in lead-poisoned children

Background

The neurotoxic effects of lead in children can have long-lasting and profound impacts on the developing nervous system. This study aimed to identify a reliable and easily accessible biomarker to monitor neurological impairment in lead-poisoned children.

Methods

We analyzed hematological data from 356 lead-poisoned children, comparing them with age and gender-matched healthy controls. Multivariate logistic regression and receiver operating characteristic (ROC) analysis were employed to identify and evaluate potential biomarkers for neurological damage.

Results

Significant changes in erythrocyte parameters were observed in lead-poisoned children. Upon further analysis, increased mean corpuscular hemoglobin concentration (MCHC) and red cell distribution width-standard deviation (RDW-SD) interaction values were found to be significantly associated with neurological impairment. The MCHC*RDW-SD interaction model demonstrated an AUC of 0.76, indicating its effectiveness in reflecting neurological damage. Additionally, the MCHC*RDW-SD Interaction value showed weak or no correlation with other erythrocyte parameters, suggesting its independence as an indicator.

Conclusion

Our findings propose the increased MCHC*RDW-SD interaction value as a robust and independent biomarker for detecting neurological impairment in lead-poisoned children. This underscores the potential of utilizing specific erythrocyte parameters for screening the neurotoxic effects of lead exposure in pediatric populations.

Intravenous iron for critically ill children. Comparison of three dose regimens

BACKGROUND

Anemia is extremely common among patients admitted to pediatric intensive care. Alternative treatments to transfusions such as intravenous iron must be considered. There are no published data for a prospective intravenous (IV) iron study focused in the critically ill children. The objective is to examine the safety and efficacy of intravenous iron sucrose infusion to manage anemia in pediatric critical care. A secondary objective is to examine the effect of different dose regimens of iron sucrose (3, 5, and 7 mg/kg dose).

PROCEDURE

Prospective investigation of intravenous iron sucrose utilization at a tertiary pediatric intensive care unit between October 2017 and November 2022.

RESULTS

In all 115 patients received a total of 616 infusions of IV iron. Transferrin saturation index (TSI) was the most common altered iron deficiency biomarker (91.8%). After IV iron treatment, hemoglobin showed a significant increase within a 30-day follow-up (9.2 vs. 11.6 g/dL, p < .001). There was also a significant improvement in TSI and serum iron (p < .001). Iron deficit replacement was higher in the 7 mg/kg dose group (94%) compared to 85.9% in the 5 mg/kg regimen and 77.5% in the lower dose group (p = .008), requiring less doses and a shorter time. Very few mild adverse reactions were reported (1.3% of infusions), with no differences between groups. The most frequent adverse effect was gastrointestinal in three cases. There were no anaphylaxis-like or other serious/life-threatening adverse effects.

CONCLUSIONS

This is the first study to evaluate intravenous iron therapy in pediatric critical care, providing preliminary evidence of safety and efficacy of IV iron sucrose. The 7 mg/kg dose regimen showed higher iron deficit replacement in a shorter time, which could be beneficial in critically ill children.

Increased monocytes are associated with overweight in children and adolescents with autism spectrum disorder

Introduction

Objective: to investigate the monocyte count and its association with nutritional status in children and adolescents with autism spectrum disorder (ASD). Methods: a cross-sectional study carried out at a Neurodevelopmental Center in the south of Brazil, with 68 ASD patients aged 3 to 18 years. The number of monocytes (per mm3) was determined in blood samples. Nutritional status was defined as BMI-for-age according to WHO standards. The Children's Eating Behaviour Questionnaire and a standard questionnaire to collect sociodemographic and clinical characteristics were administered to caregivers. Comparisons between sociodemographic, clinical, and eating behavior variables were performed with parametric tests. Linear regression was used to test the association between nutritional status and monocyte count. Results: mean age was 8.6 ± 3.3 years, 79 % were males and 66 % were overweight. In the unadjusted regression overweight was associated with higher monocyte counts compared to those non-overweight (B: 64.0; 95 % CI, 13.9 to 114.1; β: 0.30, p = 0.01). This association remained significant after adjustment for the subscale of "emotional overeating" (B: 37.0; 95 % CI, 17.1 to 91.3; β: 0.29; p = 0.02). The variability in monocyte count attributed to overweight was 14 %. Conclusions: overweight is associated with a higher monocyte count in children and adolescents with ASD. Nutritional intervention to control overweight is essential to mitigate the negative impact on inflammatory activity and immune dysfunction in these patients.

Pediatric reference intervals for hematology parameters in healthy infants and young children in Iran

INTRODUCTION

Defining accurate age- and sex-specific reference intervals (RIs) for hematology parameters, especially for the pediatric population, is important for making an appropriate clinical diagnosis. To address gaps, we established age-specific RIs for 11 hematologic parameters in Iranian children younger than 30 months for the first time.

METHODS

Fresh whole blood samples collected from a total of 344 participants (males: 158 and females: 186) ages 3 days to 30 months, with a mean age of 12.91 ± 7.15 months, were recruited from healthcare centers in Mashhad, Iran. Hematologic parameters, including complete blood count (CBC), were analyzed on the Sysmex auto-analyzer system (KX-21 N). RIs were calculated with 90% confidence intervals using the direct method based on CLSI Ep28-A3 and C28-A3 guidelines.

RESULTS

None of the CBC parameters required sex partitioning. Of 11 CBC parameters, six required age partitions of 3 days-<4 months, 4-<10, 10-<15, and 4-<30 months. Five parameters (i.e., white blood cell count, mean corpuscular hemoglobin concentration, mean platelet volume, red cell distribution width, and platelet distribution width) did not demonstrate age-specific changes. RIs of red blood cell count and hematocrit, as well as hemoglobin, increased with age, while mean corpuscular volume, mean corpuscular hemoglobin, and platelet count, decreased with age.

CONCLUSION

In this study, we established RIs for 11 hematology parameters in young children. Age partitioning was required for six parameters demonstrating marked changes during the early period of growth and development and necessitating the use of pediatric-specific reference standards.

Monocyte anisocytosis corresponds with increasing severity of COVID-19 in children

Introduction

Although SARS-CoV-2 infection can lead to severe COVID-19 in children, the role of biomarkers for assessing the risk of progression to severe disease is not well established in the pediatric population. Given the differences in monocyte signatures associated with worsening COVID-19 in adults, we aimed to determine whether monocyte anisocytosis early in the infectious course would correspond with increasing severity of COVID-19 in children.

Methods

We performed a multicenter retrospective study of 215 children with SARS-CoV-2 infection, Multisystem Inflammatory Syndrome in Children (MIS-C), convalescent COVID-19, and healthy age-matched controls to determine whether monocyte anisocytosis, quantified by monocyte distribution width (MDW) on complete blood count, was associated with increasing severity of COVID-19. We performed exploratory analyses to identify other hematologic parameters in the inflammatory signature of pediatric SARS-CoV-2 infection and determine the most effective combination of markers for assessing COVID-19 severity in children.

Results

Monocyte anisocytosis increases with COVID-19 severity and need for hospitalization. Although other inflammatory markers such as lymphocyte count, neutrophil/lymphocyte ratio, C-reactive protein, and cytokines correlate with disease severity, these parameters were not as sensitive as MDW for identifying severe disease in children. An MDW threshold of 23 offers a sensitive marker for severe pediatric COVID-19, with improved accuracy when assessed in combination with other hematologic parameters.

Conclusion

Monocyte anisocytosis corresponds with shifting hematologic profiles and inflammatory markers in children with COVID-19, and MDW serves as a clinically accessible biomarker for severe COVID-19 in children.

Comprehensive pediatric reference intervals for 79 hematology markers in the CALIPER cohort of healthy children and adolescents using the Mindray BC-6800Plus system

BACKGROUND

Hematological parameters vary significantly throughout growth and development due to physiological processes such as fetal-to-adult erythropoiesis and puberty. Pediatric age- and sex-specific reference intervals (RIs) are thus essential for appropriate clinical decision-making. The current study aimed to establish RIs for both common and novel hematology parameters on the Mindray BC-6800Plus system.

METHODS

Six hundred and eighty-seven healthy children and adolescents (30 days to 18 years) were enrolled. Participants were recruited as part of the Canadian Laboratory Initiative on Pediatric Reference Intervals Program upon informed consent or identified from apparently healthy outpatient clinics. Whole blood was collected and assayed for 79 hematology parameters on the BC-6800Plus system (Mindray). Age- and sex-specific RIs were established as per Clinical and Laboratory Standards Institute EP28-A3c guidelines.

RESULTS

Dynamic reference value distributions were observed for several hematology parameters, including erythrocytes, leukocytes, platelets, reticulocytes, and research-use-only markers. Age partitioning was required for 52 parameters, demonstrating changes in infancy and puberty. Sex partitioning was required for 11 erythrocyte parameters (i.e., red blood cell (RBC), hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin concentration, RBC distribution width coefficient of variation, hemoglobin distribution width, macrocyte count, macrocyte percentage, RBC (optical), and reticulocyte production index). Few parameters had undetectable levels in our healthy cohort (i.e., nucleated RBC count and immature granulocyte count).

CONCLUSIONS

The current study completed hematological profiling for 79 parameters on the BC-6800Plus system in a healthy cohort of Canadian children and adolescents. These data emphasize the complex biological patterns of hematology parameters in childhood, particularly at the onset of puberty, and support the need for age- and sex-specific RIs for clinical interpretation.

Hematology reference intervals in 6-12-year-old children: the health-oriented pedagogical project (HOPP)

Reference intervals are essential for correct interpretation of laboratory test results, supporting clinicians in distinguishing between healthy and sick individuals. The present study aims to establish pediatric reference intervals for hematological parameters based on a large population of healthy schoolchildren. Blood samples were obtained from 1351 children 6-12 years of age participating in the Health-Oriented Pedagogical Project (HOPP). Reference intervals for hematological parameters were estimated by the nonparametric method following the CLSI C28-A3 guidelines. Reference intervals were estimated as 2.5th and 97.5th percentiles with corresponding 90% confidence intervals. While hematocrit and MCV required age and sex partitioning, hemoglobin and erythrocytes were partitioned for age. The remaining parameters, MCH, MCHC, platelets and white blood cell counts did not require partitioning. While red blood cell parameters exhibited an increasing trend with age, there was a slight decrease in leukocytes, lymphocytes, basophils and platelets with age. The remaining parameters were stable across our age span.

Inborn Errors of Immunity Associated With Type 2 Inflammation in the USIDNET Registry

Background

Monogenic conditions that disrupt proper development and/or function of the immune system are termed inborn errors of immunity (IEIs), also known as primary immunodeficiencies. Patients with IEIs often suffer from other manifestations in addition to infection, and allergic inflammation is an increasingly recognized feature of these conditions.

Methods

We performed a retrospective analysis of IEIs presenting with allergic inflammation as reported in the USIDNET registry. Our inclusion criteria comprised of patients with a reported monogenic cause for IEI where reported lab eosinophil and/or IgE values were available for the patient prior to them receiving potentially curative therapy. Patients were excluded if we were unable to determine the defective gene underlying their IEI. Patients were classified as having eosinophilia or elevated IgE when their record included at least 1 eosinophil count or IgE value that was greater than the age stratified upper limit of normal. We compared the proportion of patients with eosinophilia or elevated IgE with the proportion of samples in a reference population that fall above the upper limit of normal (2.5%).

Results

The query submitted to the USIDNET registry identified 1409 patients meeting inclusion criteria with a monogenic cause for their IEI diagnosis, of which 975 had eosinophil counts and 645 had IgE levels obtained prior to transplantation or gene therapy that were available for analysis. Overall, 18.8% (183/975) of the patients evaluated from the USIDNET registry had eosinophilia and 20.9% (135/645) had an elevated IgE. IEIs caused by defects in 32 genes were found to be significantly associated with eosinophilia and/or an elevated IgE level, spanning 7 of the 10 IEI categories according to the International Union of Immunological Societies classification.

Conclusion

Type 2 inflammation manifesting as eosinophilia or elevated IgE is found in a broad range of IEIs in the USIDNET registry. Our findings suggest that allergic immune dysregulation may be more widespread in IEIs than previously reported.

Reference intervals of automated reticulocyte count and immature reticulocyte fraction in a pediatric population

INTRODUCTION

Reticulocytes are erythroid precursors that develop into mature erythrocytes, and they are an important tool to assess erythropoietic activity, as their count indicates the balance between the cells released from the bone marrow, their stage of maturity, and their rate of development into mature erythrocytes. Considering the described biological variability of the absolute reticulocyte count (ARC) and the immature reticulocyte fraction (IRF) and the limited information available on these hematological parameters in children, this study determined the reference intervals (RIs) of these parameters in a healthy pediatric population.

METHODS

A retrospective, observational, and analytical study was designed to establish RIs for the ARC and the IRF according to age and sex. An indirect sampling method was applied to a mixed database of complete blood counts from children aged 2 months to 18 years, using the truncated maximum likelihood indirect method for reference interval estimation. Percentiles were calculated to obtain bimodal RIs.

RESULTS

From a total of 190,812 samples, 6,814 were selected. Gender stratification was not necessary for the ARC and the IRF but they required partitioning into six and two age groups, respectively.

CONCLUSION

This study determined, by an indirect sampling method, RIs for the ARC and the IRF in a pediatric population according to age and sex.