Hematology Analyzers

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.

Evaluation of Pediatric Hematology Referrals at a Tertiary University Hospital in West Texas

One in 40 pediatric office visits in the United States result in referral to subspecialty care, mostly for secondary opinion. The aim of this study was to evaluate the necessity of pediatric hematology referrals from Eastern New Mexico and West Texas to a tertiary university hospital. Retrospective data was obtained from chart review based on referrals made to the Southwest Cancer Center in Lubbock, TX for abnormal complete blood count or coagulation tests. Necessity of referrals were assessed according to patient laboratory values before referral, at initial visit, and whether therapy was started by the primary care physician (PCP). One hundred one patients met the study criteria during the period in review. The most common reasons of referral were iron deficiency anemia, leukopenia or leukocytosis and other types of anemia. About 33% of the referrals were determined to be manageable by a PCP as either the correct therapy had been already started before referral and/or the laboratory values were back to normal at the time of the first subspecialty visit. The total estimated cost of unnecessary referrals, including clinic visits and laboratories were $82,888 excluding mileage costs, days of work-school missed, and child care. Incorporation of referral guidelines, improving communication between PCP and subspecialties, and utilizing age-sex appropriate values in the interpretation of results could prevent excessive subspecialty referrals.

Clinical and Immunological Metrics During Pediatric Rhesus Macaque Development

Background: Clinical measurements commonly used to evaluate overall health of laboratory animals including complete blood count, serum chemistry, weight, and immunophenotyping, differ with respect to age, development, and environment. This report provides comprehensive clinical and immunological reference ranges for pediatric rhesus macaques over the first year of life. Methods: We collected and analyzed blood samples from 151 healthy rhesus macaques, aged 0-55 weeks, and compared mother-reared infants to two categories of nursery-reared infants; those on an active research protocol and those under derivation for the expanded specific-pathogen-free breeding colony. Hematology was performed on EDTA-anticoagulated blood using a Sysmex XT2000i, and serum clinical chemistry was performed using the Beckman AU480 chemistry analyzer. Immunophenotyping of whole blood was performed with immunofluorescence staining and subsequent flow cytometric analysis on a BD LSRFortessa. Plasma cytokine analysis was performed using a Millipore multiplex Luminex assay. Results: For hematological and chemistry measurements, pediatric reference ranges deviate largely from adults. Comparison of mother-reared and nursery-reared animals revealed that large differences depend on rearing conditions and diet. Significant differences found between two nursery-reared cohorts (research and colony animals) indicate large influences of experimental factors and anesthetic events on these parameters. Immune cells and cytokine responses presented with distinct patterns for infants depending on age, birth location, and rearing conditions. Conclusions: Our results illustrate how the immune system changed over time and that there was variability among pediatric age groups. Reference ranges of results reported here will support interpretations for how infection and treatment may skew common immune correlates used for assessment of pathology or protection in research studies as well as help veterinarians in the clinical care of infant non-human primates. We highlighted the importance of using age-specific reference comparisons for pediatric studies and reiterated the utility of rhesus macaques as a model for human studies. Given the rapid transformation that occurs in multiple tissue compartments after birth and cumulative exposures to antigens as individuals grow, a better understanding of immunological development and how this relates to timing of infection or vaccination will support optimal experimental designs for developing vaccines and treatment interventions.

Quality management and accreditation in laboratory hematology: Perspectives from India

Quality management (QM), including quality assurance and quality control, was developed in clinical laboratories in North America and Western Europe, but must be implemented worldwide to ensure accurate, reproducible, and clinically useful results. India, a middle income country with a population of over 1.34 billion, has limited budget allotted to health care. As yet accreditation for clinical laboratories is not mandatory, which contributes to challenges in implementing good laboratory practice. This review provides a summary of internationally laid down QM principles and their application in a middle income country like India.

Type 2B von Willebrand Disease: An Unusual Cause of Severe Neonatal Thrombocytopenia

An infant with presumed maternal immune thrombocytopenic purpura had persistent thrombocytopenia with platelet clumping. The patient had no significant bleeding symptoms in the first year of life and von Willebrand antigen and ristocetin cofactor activity were normal. Absent high molecular weight multimers ultimately led to a genetically proven diagnosis of type 2B von Willebrand disease (3964G>A VWF exon 28), highlighting the challenges of establishing this diagnosis in infants.

Comparing automated vs manual leukocyte differential counts for quantifying the 'left shift' in the blood of neonates

OBJECTIVE

The neutrophil 'left shift' can be measured via the immature to total (I/T) neutrophil ratio or the absolute bands per μl using a manual differential count. It can also be measured from an automated differential count by the immature granulocyte percentage (IG%) or the absolute IG per μl. In neonates, it is unknown if the manual or automated differential count is superior.

STUDY DESIGN

We directly compared complete blood counts (CBCs) with manual and automated differential counts from infants <90 days old, and documented whether or not each neonate was infected. We developed reference intervals for I/T ratio, bands per μl, IG% and IG per μl using values from non-infected neonates.

RESULTS

The database had 10 714 CBCs. The upper reference interval for I/T ratio was 0.29 in the first 48 h and 0.31 thereafter; bands per μl was 3710 μl(-1) in the first 48 h and 1785 μl(-1) thereafter. IG% was 6.2% then 4.2%; IG per μl was 1460 μl(-1) then 613 μl(-1). Statistical performances of the four methods were equivalent for identifying infection.

CONCLUSIONS

We developed reference intervals for four methods of quantifying a neonate's 'left shift'. The information from automated differentials is not inferior to that from manual differentials in identifying infections, but automated differentials have the advantages of a larger sample size, being less expensive, and faster performance times.

Reference intervals for reticulocyte parameters of infants during their first 90 days after birth

OBJECTIVE

The automated reticulocyte parameters (absolute reticulocyte count, immature reticulocyte fraction (IRF) and reticulocyte hemoglobin content (RET-He)) are of value in managing adults and older children with a variety of hematological disorders. However, the lack of reference intervals for these parameters in neonates and young infants has limited their application to that population.

STUDY DESIGN

During a span of 12 months (29 May 2014 to 5 May 2015), a convenience sample of reticulocyte parameters were run from clinically ordered complete blood counts (CBCs) of infants within the first 90 days after birth. Measuring the reticulocyte parameters as a research-only adjunct to the CBC did not require any additional blood or generate a patient charge, and the reticulocyte results were not reported to the provided and did not appear in the clinical records. Values from neonates who had a transfusion or a diagnosis of anemia were subsequently excluded from the reference data set.

RESULTS

Nine Intermountain Healthcare clinical laboratories contributed 8438 CBCs to the initial reticulocyte parameter database. From these, 1806 were excluded because of a transfusion or a diagnosis of anemia, leaving 6632 in the reference interval database. The parameters charted over the first 90 days after birth were: (1) blood hemoglobin concentration (g dl(-1)), (2) mean corpuscular volume (fL), (3) reticulocyte count (x10(3) per μl), (4) IRF (%) and (5) RET-He (pg).

CONCLUSIONS

The new reference interval charts can help clinicians identify abnormalities in the reticulocyte parameters. This information could be of value in identifying and following neonates with various hematological problems including hemolytic disorders, occult hemorrhage, or iron deficiency or other limitations of erythrocyte production.