Reference Range Research Articles

Reference intervals for trace minerals and heavy metals in livers of cattle in wilderness areas in the Netherlands.

We examined the liver mineral concentrations of semi-wild cattle breeds (Highland, Galloway, Rode Geus) grazing in natural or near-natural flood-prone areas in the Netherlands. These breeds are employed as part of trophic rewilding initiatives aimed at maintaining biodiverse ecosystems through natural grazing patterns. Our primary goal was to derive RIs for liver mineral concentrations for these cattle populations. We collected and analyzed liver samples from 96 cattle from 14 sites in the Netherlands and used inductively coupled plasma mass spectrometry to measure concentrations of trace elements and heavy metals, including arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, molybdenum, nickel, selenium, vanadium, and zinc. The statistical analysis included Pearson product moment correlations and k-means clustering to evaluate patterns within the data. The highest significant correlations were between liver cadmium concentrations and animal age, and between liver copper and selenium concentrations. Breed-related differences were found for liver cadmium and molybdenum concentrations, but we could not isolate breed-differences in forage selection from environmental variables such as soil composition. Liver copper levels in many animals were below thresholds typically used to indicate copper deficiency in farmed cattle.

Evaluation of Three-Vessel View Intervessel Distance Measurements in Fetuses Without Congenital Cardiac Defects.

We aimed to compare the intervessel distances on standard 3-vessel views during fetal echocardiography across nonanomalous fetuses between 18 and 23 weeks' gestation. The intervessel measurements included the distances between the main pulmonary artery (PA) and ascending aorta (Ao) (PA-Ao), between Ao and superior vena cava (SVC) (Ao-SVC), and between PA and SVC (PA-SVC). Throughout a 2-year period, 95 low-risk pregnancies as controls were included. Two evaluators measured intervessel distances from archived images. Scatter plots that included gestational age, femur length (FL), biparietal diameter (BPD), and intervessel distance measurements for nonanomalous fetuses were formed. Inter- and intraobserver reliabilities were assessed by intraclass correlations (ICC). In normal fetuses, PA-Ao and Ao-SVC distance values did not significantly change (p = 0.62 and p = 0.09, respectively), although PA-SVC distance measurements increased (p = 0.0001) with increasing gestational weeks. Interobserver and intraobserver agreement for PA-Ao distance were moderate (ICC, 0.63) and high positive (ICC, 0.79); for Ao-SVC distance, it was low positive (ICC, 0.47) and moderate (ICC, 0.59); for PA-SVC distance, it was high positive (ICC, 0.76) and high positive (ICC, 0.89), respectively. Reference intervals for intervessel distances PA-Ao, Ao-SVC, and PA-SVC in the three-vessel view at 18-23 weeks of gestation were established.

Body Surface Gastric Mapping Delineates Specific Patient Phenotypes in Adolescents With Functional Dyspepsia and Gastroparesis.

Diagnosing pediatric patients with chronic gastroduodenal symptoms is clinically challenging, with the role of gastric emptying testing being controversial. Body Surface Gastric Mapping (BSGM) is a new diagnostic test that can identify specific patient phenotypes in adults with gastric dysfunction. This study evaluates whether BSGM can delineate specific phenotypes in adolescents and provide clinically meaningful distinctions between gastroparesis and functional dyspepsia diagnoses. A prospective cross-sectional study recruited adolescents aged 12 to 21 between 2022 and 2024. Controls were recruited from New Zealand and patients from the Children's Hospital of Philadelphia, USA. BSGM followed a standardized protocol, including simultaneous symptom reporting and completion of validated symptom, psychometric, and physical health questionnaires. Fifty-six subjects were recruited (31 controls, 25 patients); median age 16; 96% of patients were female. Control data showed that adult reference intervals provided an acceptable interpretation framework. Patients with FD (n = 10) and gastroparesis (n = 15) had common symptoms, mental health, quality of life, and functional disability (all p > 0.05). Three distinct BSGM phenotypes were identified: BSGM Normal (n = 10), BSGM Delay (n = 8), and Low Stability/Low Amplitude (n = 7), having spectral differences in BMI-Adjusted Amplitude 34.6 versus 39.1 versus 19.9 (p = 0.01) and Gastric Alimetry Rhythm Index: 0.45 versus 0.45 versus 0.19 (p = 0.003). BSGM phenotypes demonstrated differences in symptoms (nausea p = 0.04), physical health (p = 0.04), and psychometrics (anxiety p = 0.03). Adolescents with FD and gastroparesis have overlapping clinical profiles, making treatment challenging. Conversely, employing BSGM to categorize patients into distinct phenotypes reveals clinically relevant differences, offering avenues for individualized therapeutic pathways.

Pediatric Vaccine-Induced Antibody Thresholds: Rethinking Pre-Immunosuppression Serologic Testing and Revaccination Implications.

Immune response to vaccination is assessed when adequate vaccine protection is in question or immunosuppression is imminent through measurement of antibody levels, which wane as time from vaccination increases. The serologic cutoff value for adequate response is based on thresholds derived from studies in adults, and age-appropriate thresholds for children have not been established. We sought to investigate age-specific differences in antibody levels in healthy children to guide determination of vaccine immunity status when clinically indicated. This cross-sectional study assessed clinical serology for measles, mumps, rubella (MMR), varicella, and hepatitis B (HepB) in an age-stratified cohort of 471 healthy children who were up to date for vaccination (1 to 18 years). Remnant specimens with sufficient volume were collected from July 23, 2019, to November 17, 2020, as convenience samples and chart reviewed for inclusion. While children of all ages had detectable titers to MMR, median titers for HepB and varicella waned by ages 11 to 12 and 9 to 10 years, respectively. Children had titers above adult thresholds for MMR at all measured timepoints, retrospectively resulting in 24.6% (95% CI, 21.6%-27.8%) of children having an inappropriate MMR classification when adult instead of pediatric thresholds were used. Current use of HepB and varicella serology may be inappropriate due to the rapid waning of titers. The adequacy of an individual's response to one vaccine component did not infer adequate responses to other components. Application of age-appropriate reference intervals for vaccine serologic tests will provide a foundation for improved treatment recommendations and standards of care.

An Exploratory Cross-Sectional Study on Thyroid Hormone Reference Intervals in Children With Down syndrome.

Accurate evaluation of thyroid dysfunction in children with Down syndrome is challenging because of the lack of age-specific reference intervals in these individuals. This study aimed to establish age-specific reference intervals for thyroid-stimulating hormone (TSH) and free thyroxine (FT4) levels in children with Down syndrome. A retrospective cross-sectional study was conducted on children with Down syndrome, aged 6 months to 15 years, who visited the Osaka Women's and Children's Hospital between April 2019 and March 2020. Subjects who had used medications that influenced thyroid function or who lacked thyroid hormone data were excluded from the study. The final analysis included 301 subjects. Serum TSH and FT4 levels were measured, and reference intervals were calculated using nonparametric methods. The reference intervals for TSH in children with Down syndrome were 2.03-14.22, 1.79-12.98, 1.26-10.24, and 0.58-10.11 mIU/L in infants, toddlers, school children, and adolescents, respectively, which were higher than those observed in the general paediatric population. The reference intervals for FT4 were 13.57-26.42, 13.20-22.70, 13.15-22.36, and 11.97-24.77 pmol/L, respectively, which were comparable to those of the general paediatric population. Multivariate regression analyses revealed a significant inverse association between age and the levels of TSH and FT4 (p < 0.01). We provide evidence for age-specific reference intervals for TSH and FT4 levels in children with Down syndrome, which may help clinicians accurately evaluate thyroid hormone status.

Analysis of blood test results of primary and secondary school students in high altitude areas

ObjectiveTo explore the blood level and its change trend of primary and secondary school students aged 6 ~ 18 years in high altitude area (4300 m above sea level), and to provide a reference basis for the establishment of reference interval of blood cell analysis for children in high altitude area.MethodsPrimary and secondary school students aged 6 to 18 in Ali, Tibet (4300 m above sea level) were used as the study subjects. Routine blood tests were performed during routine physical examinations to compare the blood levels of primary and secondary school students of different genders in the four age groups of 6–9, 10–12, 13–15, and 16–18 years old and to analyze the trends of changes with age and gender.ResultsThe differences in the routine blood indicators of WBC, Lymph, Mid, Mid%, MCV, MCH, MPV, P-LCC, and P-LCR among primary and secondary school students at high altitudes were statistically significant in different age groups (P < 0.05); the routine blood indicators of Lymph, MCV, MCH, and RDW-CV among primary and secondary school students of different genders at high altitude were statistically significant in the age groups of 6–9 years old and the age groups of 16–18 years old and the age groups of 10–12 years old, 13–15 years old and 16–18 years old, respectively. MCV, MCH, MCHC and RDW-CV at the age of 10 ~ 12 years, NEUT, RBC, MCV, MCH, MCHC, RDW-SD and PDW at the age of 13 ~ 15 years, and the differences of WBC, NEUT, RBC, HGB, HCT, MCHC, MPV, PDW, P-LCC and P-LCR in male and female students at the age of 16 ~ 18 years are statistically significant (P < 0.05); WBC, LYM, Mid, Mid% and PLT showed a linear decreasing trend with age in both sexes (P < 0.01), and HGB, MCV, MCH, RDW-SD, MPV, PDW and P-LCR showed a linear increasing trend with age in both sexes (P < 0.01).ConclusionThe blood routine indexes of primary and secondary school students in high altitude areas differed between different age groups and genders, and influencing factors such as age and gender should be considered when formulating reference intervals for blood cells of children in high altitude areas.

Big data determination and validation of reference range for 24 hour urine cortisol by LCMS/MS.

24-hour urine free cortisol(UFC) is a first line test for Cushing syndrome(CS). A new mass spectrometry assay for UFC requires a validated, relevant reference range appropriate to a screening population. Combined retrospective and prospective cohort study in a government health system and tertiary endocrinology clinic, Canada. Participants were patients with potential features of CS. The refineR reference interval algorithm was used to derive a middle 95%ile reference interval from 4830 UFC results in non-CS patients, compared with 120 prospective patients where evaluation excluded CS. UFC and 24-hour urine volume were correlated (r=0.28, p<0.0001). There was no significant difference between the volume-corrected UFC distributions in the prospective vs retrospective populations (p=0.09). UFC distribution was highly skewed (p<0.0001) and showed strong sex interaction. The refineR-generated adult male UFC upper reference limit was 238 nmol/day (86.3 ug/day) and for females was 147 nmol/day (53.3 ug/day); urine volume-corrected, the upper limits were 89 nmol/L (32.3 ug/L) and 91 nmol/L (32.9 ug/L) respectively. Applied to both populations, between 3-8% of all results would be flagged high; most are expected to represent non-neoplastic (pseudo)Cushing's. We used mass population data, where the prevalence of CS was likely very rare, plus a carefully phenotyped sample where CS was considered but excluded, to derive a validated reference interval for 24-hour UFC by mass spectrometry in populations that reflect real world use of the test. Given the highly-skewed upper tail of the population distribution, it is probable that high test specificity for CS will require multi-modality diagnostic confirmation.

Reference intervals for holotranscobalamin and total vitamin B12 in 6–12-year-old children in Norway: the Health Oriented Pedagogical Project (HOPP)

Vitamin B12 (B12) is essential for DNA synthesis in all cells and for the development and maintenance of a healthy nervous system. B12 is transported in the circulation bound to two carrier proteins, haptocorrin and transcobalamin, measured as the biomarkers total B12 and holotranscobalamin (holoTC). The latter measures the fraction of cobalamin available for tissue uptake and is considered to have a better sensitivity and specificity for diagnosing vitamin deficiency. The concentration of both carrier proteins depends on age, but data on paediatric reference values for holoTC are still sparse. Blood samples were obtained from 1320 healthy school children, mainly Caucasians (age 6–12 years old) in three different municipalities in Norway. The holoTC and total B12 levels were determined by chemiluminescent microparticle immunoassay on the Architect 2000 analyser. Age specific paediatric reference intervals (RIs) were estimated by calculating the 2.5 and 97.5 percentiles by the nonparametric method with corresponding 90% confidence intervals, according to the Clinical and Laboratory Standards Institute C28-A3C guidelines. The 95% RIs for total B12 were 295–1066 pmol/L for children 6–8 years old, and 249–879 pmol/L for children 9–12 years old. Reference intervals for holoTC were ≥56 pmol/L for children 6–8 years old, and ≥37 pmol/L for children 9–12 years old. Age specific RIs will aid clinicians in interpretation of cobalamin results in children aged 6–12 years old.

Decrease in the internal quality control intermediate reproducibility imprecision of Cystatin C results in China in the years from 2014 to 2023.

We evaluated the intermediate reproducibility imprecision of cystatin C results based on internal quality control (IQC) data. Five performance specifications [1/3 total allowable error (TEa), 1/4TEa and three levels performance specifications based on biological variation] were used to calculate the proportion of laboratories with CVs less than or equal to the performance specifications, namely the pass rate. Based on the reference interval of Chinese adult serum cystatin C (0.59-1.03 mg/L), the concentration of quality control materials was divided into two levels for CV analysis: Level 1 (≤1.03 mg/L) and Level 2 (>1.03 mg/L). Additionally, group analysis was conducted according to the reagent manufacturer. Peer groups were further divided based on instruments to study differences between instruments. The intermediate reproducibility imprecision of Cystatin C IQC results in China had decreased from 5.1% (CV%) in 2014 to 3.3% in 2023. The pass rates based on 1/3 TEa showed upward trends increasing from 67% in 2014 to 88% in 2023. The CVs of two concentration levels showed significant differences in most years. Roche Diagnostics reagent manufacturer exhibited low intermediate reproducibility imprecision. The BSBE-Abbott Architect series platform achieved a 100% pass rate based on 1/3 TEa in 2023. The intermediate reproducibility imprecision of cystatin C has been a continuous overall improvement in China. However, the performance specifications of Cystatin C based on BV are currently not applicable to some laboratories in China. In addition, attention should be paid to the differences in intermediate reproducibility imprecision between various analysis systems.

Malondialdehyde (MDA) and 8-hydroxy-2’-deoxyguanosine (8-OHdG) levels in canine serum: establishing reference intervals and influencing factors

BackgroundMounting evidence suggests that malondialdehyde (MDA) and 8-hydroxy-2’-deoxyguanosine (8-OHdG) are valuable biomarkers of lipid and nucleic acid oxidation in numerous canine diseases. However, their application in clinical settings is limited due to the absence of reference intervals (RI) and the analytical inconsistencies. Therefore, this study aimed to characterize serum MDA and 8-OHdG concentrations in dogs, to establish assay-specific RI, and to identify biological, haematological and biochemical factors influencing these markers.MethodsA total of 190 clinically healthy dogs were recruited, including pet dogs, working dogs and shelter dogs. Serum MDA concentration was measured by the Thiobarbituric Acid Reactive Substances (TBARS) assay, while 8-OHdG levels were determined by using a competitive ELISA. RI were established by non-parametric methods. Potential associations between oxidative stress (OS) biomarkers and multiple biological, haematological and biochemical factors were assessed using multivariate regression models.ResultsRI for serum MDA (1.85–14.51 µM) and 8-OHdG (0.06–0.75 ng/mL) were established in the reference population (144 and 143 dogs, respectively). The multivariate regression model for MDA revealed a positive association with total cholesterol concentration, and a negative association with monocyte count. 8-OHdG level was positively associated with urea concentration. Notably, both models also revealed a significant association between MDA and 8-OHdG. Biological factors, including the age and size of the animals, did not exert a significant influence on the results.ConclusionsThis is the first study to establish serum RI for MDA and 8-OHdG in a large and diverse canine population. Additionally, the multivariate regression models identified relevant haematological and biochemical, but not biological factors that should be considered when interpreting the results. These findings could significantly enhance the application of MDA and 8-OHdG as biomarkers in clinical settings, and promote further exploration of their value in canine diseases.

The Correlation of Vitamin D Concentrations in Healthy Pregnant Women and Their Infants with Outcome Parameters.

The objective of this prospective study was to assess the concentration and impact of maternal 25(OH)D status on neonatal vitamin D concentrations and early neonatal outcomes in the newborns of mothers who did not take vitamin D supplements during pregnancy. The study is a cohort prospective study of the correlation of VD concentrations in mothers and their newborns. The study included 100 pairs. Only 16 mothers had a VD concentration in the reference interval (75-100 nmol/L), while 84 mothers had values less than 75 nmol/L (p<0.001). A significant difference in maternal VD concentration was determined in relation to tobacco consumption habits during pregnancy and placental condition (p<0.001). 95% of the neonates (95/100) of older, obese multigravida, who had hypovitaminosis D and inadequate exposure to sunshine, had normal VD concentrations (the mean=49.27 nmol/L) on the first day of life. The majority of the mothers gave birth to full-termnewborns with normal vitality scores and CRP and bilirubin levels in the reference interval. The conclusion of this prospective study is that 84% of the healthy pregnant women had hypovitaminosis D. However 95% of their newborns were born full term, with normal anthropometric measurements, normal vitality scores, and normal VD concentrations. This study also confirmed that there is still no cause-and-effect association between hypovitaminosis D in pregnant women and their offspring with outcome parameters for both.

Reference intervals for CD4 and hemoglobin among apparently healthy pregnant women in Addis Ababa, Ethiopia

BackgroundMost African countries, including Ethiopia, have not developed local well-defined reference intervals (RIs) for immuno-hematological testes in terms of pregnant women. As a result, we were using reference intervals derived from non-Africans. This is not appropriate because CD4 + T cell counts (CD4 count) are affected by several factors including ethnic and environmental factors. Therefore, this study aimed to develop reference interval for CD4 count for apparently healthy pregnant women in Addis Ababa, Ethiopia.ResultsAfter excluding six pregnant women who did not pass the screening tests, 156 apparently healthy pregnant women who were 18–49 years old were included in the final analysis. The medians of CD4 absolute counts and CD4% with inter-quartile ranges [IQR] were 757.5 [611.3-925.5] cells/µL and 43.6% [39.9–47.3] respectively while the median and IQR hemoglobin values were 14.3 g/dL [13.4–15.1]. The respective reference intervals for absolute CD4 cell count and % CD4 were 416.9-1218.4 cells/µL and 32.1–57.3%, respectively. Significant changes were observed in hemoglobin level between trimesters (P < 0.05).ConclusionThe results of this study showed a decrease in both percentage and absolute CD4 + T cell counts when compared to those of non-African and African countries. Establishing local reference values for diverse groups is therefore crucial.

Unveiling the power of R: a comprehensive perspective for laboratory medicine data analysis

Abstract R language has gained traction in laboratory medicine for its statistical power and dynamic tools like RMarkdown and RShiny. However, there is limited literature summarizing R packages and functions tailored for laboratory medicine, making it difficult for clinical laboratory workers to access these tools. Additionally, varying algorithms across R packages can lead to inconsistencies in published reports. This review addresses these challenges by providing an overview of R’s evolution and its key features, followed by a summary of statistical methods implemented in R, including platform comparisons, precision verification, factor analysis, and the establishment of reference intervals (RIs). We also highlight the development and validation of predictive models using techniques such as linear and logistic regression, decision trees, random forests, support vector machines, naive Bayes, K-Nearest Neighbors, k-means clustering, and backpropagation neural networks – all implemented in R. To ensure transparency and reproducibility in research, a checklist is provided for authors publishing papers using R for data analysis in laboratory medicine. In the final section, the potential of R in big data analytics is explored, focusing on standardized reporting through RMarkdown and the creation of user-friendly data visualization platforms with RShiny. Moreover, the integration of large language models (LLMs), such as ChatGPT, is discussed for their benefits in enhancing R programming, automating reporting, and offering insights from data analysis, thus improving the efficiency and accuracy of laboratory data analysis.

Performance evaluation of Rayto RT-7600Vet hematology analyzer in side-by-side comparison with manual hematological methods for apparently healthy Cholistani cattle blood.

The present study is the first from Pakistan being reported with an objective to assess performance of Rayto RT-7600Vet hematology analyzer (HA) for Cholistani cattle blood (n = 134), in comparison to the manual hematological methods. The four hematological attributes viz. total erythrocyte count (TEC), hemoglobin (Hb), packed cell volume (PCV) and platelet count (PLT) were deduced through HA (A) and manual (M) methods. Various statistical tests were implied to ascertain level of interrelationship, accuracy and level of agreement between the two methods. All attributes attained through manual methods had high positive, leptokurtic distribution (having many outliers) except for PLT-M and PCV-M. The coefficient of variation for attributes attained through HA and manual methods ranged from 16-24% and from 16-59%, respectively. Comparison between the overall results revealed that all the studied attributes, except TEC, were significantly (P≤0.05) different for both methods. A weak relationship was noticed between the attributes attained through two methods as indicated by weak r-values and adjusted r-square values. The reliability level of estimating Hb and PCV had highest intraclass correlation coefficient value of 0.722 and 0.555 for average measures, respectively. However, accuracy level, as determined through Lin's concordance correlation coefficient was highest for TEC (0.9504) for both analytical methods. Poor level of agreement, in general, was shown for the two methods of analysis regarding all four hematological attributes through Bland and Altman test. In conclusion, the Rayto RT-7600Vet) may present data having higher skewness, kurtosis, and CV%, however, they are valid for multi-species hematological analysis. Caution must however, be taken in interpreting their results with corrected reference intervals and CV% for each machine and for each tested attribute.

ESTABLISHING REFERENCE INTERVALS FOR SERUM INFLAMMATORY MARKERS AND INVESTIGATING THEIR STORAGE STABILITY AND CLINICAL UTILITY IN ASIAN WILD HORSES (EQUUS FERUS PRZEWALSKII) UNDER MANAGED CARE.

Acute phase proteins (APPs) are commonly used in domestic equine practice, where they rise rapidly in response to inflammation and decrease soon after resolution. This response provides useful information to identify, monitor, and prognosticate a variety of inflammatory conditions. Asian wild horses (Equus ferus przewalskii) are an endangered relative of the domestic horse, and APP reference intervals (RI) and clinical utility in this species are not well documented. This study used serum samples from clinically healthy Asian wild horses under managed care to establish RI for serum amyloid A (SAA, n = 21) using an equine SAA assay and haptoglobin (HP, n = 23) using a proprietary assay. The utility of SAA and HP in identifying inflammation in clinically abnormal horses was assessed, and storage stability of these analytes under refrigerated conditions was determined. The RIs established in this study were 0.3-6.8 mg/L for SAA and 0-3.25 g/L for HP. Six clinically abnormal cases were retrospectively assessed using the RI established in this study. One case of pituitary neoplasia showed elevated SAA levels, one case of maxillary lip phaeohyphomycosis and concurrent endometritis showed elevations in SAA and HP, and one case of chronic laminitis had elevated SAA. Storage stability of SAA and HP were assessed at 4°C over 7 d. SAA significantly decreased between Time 0 h and Time 72 h, but increased again at 7 d with no significant difference between Time 0 h and Time 7 d. Because of the initial decrease in SAA concentration over the first 72 h, it is recommended that SAA is analyzed within 48 h if freezing or immediate analysis is not possible. There was no significant difference between HP between Time 0 h and Time 7 d, suggesting stability of this analyte over this period if freezing or immediate analysis is not possible.

ASSESSMENT OF ECHOCARDIOGRAPHIC PARAMETERS IN HEALTHY FREE-RANGING GIANT ANTEATERS (MYRMECOPHAGA TRIDACTYLA).

The aim of this study was to conduct Doppler echocardiography on healthy free-ranging anteaters (Myrmecophaga tridactyla) and to evaluate the relationship between echocardiographic parameters of diagnostic importance and animal body weight (BW). This work utilized 8 anesthetized adult animals and 4 manually restrained pups. The echocardiographic examinations were performed with the animal in left lateral recumbency. The echocardiographic scans were directed toward the parasternal window. Four cuts of the cardiac silhouette were conducted, two longitudinal and two transverse, to evaluate the systolic and diastolic cardiac parameters. This study recorded the following parameters: interventricular septum (IVS), left ventricular internal diameter (LVID), left ventricular posterior wall (LVPW), ejection fraction (EF), shortening fraction (SF), aortic valve diameter (AOD), and left atrial diameter (LAD). The BW data (kg) of each giant anteater were paired with their respective echocardiographic data. These data were analyzed using correlation and linear regression modeling to assess the extent of the associations between the variables and their reliability. The same associations were analyzed with canine data to compare and determine the possibility of extrapolating the findings between dogs and anteaters. The echocardiographic parameters obtained using M-mode ultrasound from the short-axis transverse sections were adjusted to the left parasternal window because of the difficulty in analyzing them in the right parasternal window. The correlations between the echocardiographic parameters and the BW were found to be reliable, indicating that they could potentially be used as a simulation model for anteaters when an adequate number of animals are included in the analysis. The verification of the echocardiographic values obtained in anteaters utilizing reference intervals for dogs demonstrated acceptable hit rates, although the statistical results were not satisfactory.

EVALUATION OF THE OCULAR PARAMETERS AND LESIONS IN A FLOCK OF AQUARIUM-HOUSED AFRICAN BLACK-FOOTED PENGUINS (SPHENISCUS DEMERSUS).

African black-footed penguins (Spheniscus demersus) are one of the most common penguin species exhibited in zoos and aquariums. Ophthalmic literature published in this species is limited to intraocular pressure (IOP) and corneal thickness. The objective of this research was to evaluate IOP (rebound tonometry; dog setting), tear production, corneal fluorescein staining, and ocular lesions from 48 eyes of 24 penguins (aged 4.29-29.58 yr) at Ripley's Aquarium of the Smokies. Statistical analysis revealed that tear production (12.68 ± 4.59 mm/min [mean ± SD], with a modified half strip in 25 eyes) was not affected by sex or weight or between left and right eyes. Schirmer tear measurements were observed to decrease with age (P = 0.008). IOP (29.81 ± 4.88 mm Hg [mean ± SD]) was not affected by sex, weight, or age or between left and right eyes. Faint corneal fluorescein uptake was observed in four eyes, indicating stippled-to-patchy erosions on the corneal epithelium. Cataracts were the most common ocular lesion (50%; 12/24 penguins) and mostly incipient anterior subcapsular. Increased age (P = 0.024) was determined to be a risk factor for cataracts. Other ocular lesions observed in this group were corneal fibrosis, diffuse chemosis, and perilimbal corneal conjunctivalization. This study contributes to species-specific ocular reference intervals for African black-footed penguins and characterizes their most common ocular lesions.

Laboratory Reference Intervals for Routinely Analyzed Transferrin and Unsaturated Iron-Binding Capacity Parameters in the Adult Population of Uasin Gishu County, Kenya

Reference intervals (RIs) are used in the interpretation of clinical laboratory data to help doctors reach a medical decision point. However, due to a variety of reasons, RIs varies significantly between various populations. This study aimed at establishing transferrin, and IUBC reference intervals that can be used locally for the interpretation of iron indices at MTRH. A cross sectional study was conducted at Moi Teaching and Referral Hospital, 290 healthy volunteers were enrolled in the study where their transferrin and IUBC were examined. The non-parametric approach was used to determine reference values with a 95% confidence interval. The Sigma diagnostics approach was used to verify the established Ris. IBM SPSS version 23.0 was used to conduct the statistical analysis. Mann-Whitney U tests were used to compare genders for significant differences. The established reference intervals for Transferrin: males: 2.13–4.01 g/L, females, 2.08–4.04 g/L; UIBC: males, 20.50–64.08 umol/L, females: 20.07–64.21 umol/L. Comparisons between genders for significant differences were done using Mann-Whitney U tests, revealing no significant gender-based differences between transferrin and UIBC exhibited. The established reference intervals in this study are age and sex-specific for routinely used transferrin and IUBC catering for the adult population of Uasin Gishu County aged 18–64 years. The result will assist the clinicians in reaching an informed medical decision.

Comparison and application of direct and indirect methods in establishing reference intervals for coagulation tests

This study aimed to establish adult reference intervals for coagulation parameters using the CN-6000 fully automated coagulation analyzer. It also compared the applicability of direct and indirect methods in different populations. A cross-sectional and retrospective design was employed. The direct method included patients from the colorectal surgery and dermatology departments, as well as healthy participants from phase I clinical trials, admitted to the West Campus of China-Japan Friendship Hospital from April to December 2023. Participants were divided into two age groups: younger adults (18-64 years) and older adults (≥65 years). Coagulation parameters were tested, and reference intervals were determined. The indirect method applied the refineR algorithm to analyze coagulation data from non-ICU patients during the same period. The performance of both methods was evaluated in healthy participants, relatively healthy patients, and patients with high disease prevalence. The results showed that the direct method yielded similar reference intervals for APTT, PT, and TT in younger and older groups, with combined intervals of 23.7-31.2 seconds, 10.4-12.8 seconds, and 14.7-17.5 seconds, respectively. However, the Fib showed a significant difference between the two groups (U=1 052 023, P<0.01), and separate reference intervals were established: 1.7-4.5 g/L for the younger group and 2.1-4.6 g/L for the older group. The reference intervals derived by the indirect method are similar to those from the direct method: APTT 23.8-31.4 seconds, PT 10.4-13.0 seconds, TT 14.5-17.4 seconds, and Fib 1.8-4.3 g/L (18-64 years) and 2.1-4.5 g/L (≥65 years). In relatively healthy patients, the reference intervals obtained by both methods were comparable, but significant differences were observed in patients with high disease prevalence. In conclusion, this study established localized reference intervals for the CN-6000 fully automated coagulation analyzer. The indirect method can serve as an alternative to the direct method in healthy and relatively healthy populations. However, its applicability in populations with high disease prevalence is limited and requires cautious interpretation in the context of clinical settings.

Haptoglobin in pregnancy: Trimester-specific reference intervals.

Pregnancy induces physiologic changes that can affect serologic and immunologic markers, potentially resulting in lower haptoglobin values than nonpregnant counterparts. Such variations may lead to concern for hemolysis in pregnancy. This study aims to analyze reference intervals (RIs) for haptoglobin in each trimester of pregnancy. We employed a quality improvement project to analyze a total of 401 remnant serum samples (BD Vacutainer SST) collected from routine outpatient pregnancy patients. Roche Cobas 8000 (c 502) systems were used to examine at least 80 samples per trimester: first trimester (86 samples), second trimester (230 samples), and third trimester (80 samples). Haptoglobin between trimesters was compared using the Mann-Whitney test. Nonparametric RIs were calculated to be 27 to 196mg/dL for the first trimester, 27 to 178mg/dL for the second trimester, 34 to 191mg/dL for the third trimester, and 30 to 185mg/dL for the entire sample population. The distribution of second-trimester haptoglobin (median, 98mg/dL) was significantly different compared to the first trimester (median, 113.5mg/dL; P < .05) and the third trimester (median, 112.5mg/dL; P < .05). Although overall haptoglobin RI during pregnancy aligned with the nonpregnant population, our study revealed a significant shift during the second trimester. This finding suggests that pregnant individuals in the second trimester may have lower haptoglobin values and potentially be misdiagnosed with intravascular hemolysis when consequent added factors further decrease haptoglobin below the level of detection without hemolysis.