Pediatric reference intervals for alkaline phosphatase

Effects of a preoperative neuromobilization program offered to individuals with carpal tunnel syndrome awaiting carpal tunnel decompression surgery: A pilot randomized controlled study

STUDY DESIGN

Pilot randomized controlled trial with parallel groups.

INTRODUCTION

Engaging individuals with carpal tunnel syndrome (CTS) awaiting carpal tunnel decompression surgery in a preoperative rehabilitation program may mitigate pain and sensorimotor impairments, enhance functional abilities before surgery, and improve postoperative outcomes.

PURPOSE OF THE STUDY

To assess the feasibility and the efficacy of a novel preoperative neuromobilization exercise program (NEP).

METHODS

Thirty individuals with CTS were randomly allocated into a four-week home-based neuromobilization exercise group or a standard care group while awaiting surgery. Outcome measures included feasibility (ie, recruitment, attrition, adherence, satisfaction, and safety) and efficacy metrics (ie, median nerve integrity and neurodynamics, tip pinch grip, pain, and upper limb functional abilities) collected before (ie, at the baseline and about four weeks later) and four weeks after surgery.

RESULTS

Thirty individuals with CTS were recruited (recruitment rate = 11.8%) and 25 completed the study (attrition rate = 16.7%). Adherence (94%) and satisfaction with the program (eg, enjoy the exercises and likeliness to repeat the NEP (≥4.2/5) were high and no serious adverse event was reported. NEP-related immediate pre- and post-surgery beneficial effects on pain interference were documented (P = .05, η² = .10), whereas an overall increased neurodynamics (P = .04, η² = .11) and decreased pain severity (P = .01, η² = .21) were observed.

DISCUSSION

Engaging in the proposed NEP has limited beneficial effect as a stand-alone intervention on pre- and post-surgery outcomes for individuals with CTS. Expanding the program's content and attribute by adding other components including desensitization maneuvers and novel therapies promoting corticospinal plasticity is recommended.

CONCLUSION

A preoperative NEP completed by individuals with CTS awaiting surgery is feasible, acceptable, and safe. However, given the limited beneficial effectsof the program, revision of its content and attributes is recommended before proceeding to large-scale trials.

Age-wise trends in alkaline phosphatase activity in 167,625 Chinese children aged 0-18 years

OBJECTIVE

Alkaline phosphatase (ALP) serves as a biomarker for diagnosing several types of diseases in adults; nonetheless, its use is restricted in children because of changes in ALP activity during different physiological phases. The present study aimed to investigate ALP activity and its dynamics in children of different ages to establish the reference values for ALP activity in children.

METHODS

Total 167,625 samples of children aged 0-18 years were enrolled in this study. ALP activity was measured using the 4-nitrophenyl-1-phosphate disodium salt (4-NPP)-2-amino-2-methyl-1-propanol (AMP) method with an automatic biochemical analyzer. Patients with known diagnoses that may affect ALP activity were excluded. A percentile curve was plotted using MATLAB software, and the curve was fitted using the skewness-median-coefficient of variation (LMS) method.

RESULTS

ALP activity reached the highest peak at 12-13 years of age and then gradually decreased to the lowest peak at 18-19 years of age in boys, whereas it reached the highest at 10-11 years and then gradually reduced to the lowest at 17-18 years in girls. Furthermore, the highest peak of ALP activity appeared substantially earlier in children of either sex in China than in those in Germany.

CONCLUSIONS

We showed the dynamics of ALP activity in both boys and girls between the ages of 0 and 18 years in China and compared the difference in ALP activity between children in China and Germany. Our findings provide a reference for clinicians.

Reference Interval Estimation from Mixed Distributions using Truncation Points and the Kolmogorov-Smirnov Distance (kosmic)

Appropriate reference intervals are essential when using laboratory test results to guide medical decisions. Conventional approaches for the establishment of reference intervals rely on large samples from healthy and homogenous reference populations. However, this approach is associated with substantial financial and logistic challenges, subject to ethical restrictions in children, and limited in older individuals due to the high prevalence of chronic morbidities and medication. We implemented an indirect method for reference interval estimation, which uses mixed physiological and abnormal test results from clinical information systems, to overcome these restrictions. The algorithm minimizes the difference between an estimated parametrical distribution and a truncated part of the observed distribution, specifically, the Kolmogorov-Smirnov-distance between a hypothetical Gaussian distribution and the observed distribution of test results after Box-Cox-transformation. Simulations of common laboratory tests with increasing proportions of abnormal test results show reliable reference interval estimations even in challenging simulation scenarios, when <20% test results are abnormal. Additionally, reference intervals generated using samples from a university hospital's laboratory information system, with a gradually increasing proportion of abnormal test results remained stable, even if samples from units with a substantial prevalence of pathologies were included. A high-performance open-source C++ implementation is available at https://gitlab.miracum.org/kosmic.

Is it possible to diagnose fulminant Wilson's disease with simple laboratory tests?

BACKGROUND

Wilson's disease is a rare cause of acute liver failure and is highly fatal without liver transplantation. Fast and accurate diagnostic methods are needed for fulminant Wilson's disease (FWD). In this study, we aimed to develop an early, simple and accurate diagnostic method to differentiate FWD from nonwilsonian acute liver failure (NWALF) causes using routine biochemical data.

METHODS

The medical records of 24 paediatric FWD and 120 paediatric NWALF cases diagnosed at the Department of Pediatric Gastroenterology, Hepatology, and Nutrition between January 2007 and February 2017 were retrospectively reviewed.

RESULTS

Using receiver operator characteristics curve (ROC) analysis, we have determined the best cut-off point for laboratory findings in FWD. Patients meeting these cut-off points were assigned one point and others were assigned zero point. We then formed a new variable consisting of the combination of 14 variables and performed a new ROC analysis. We obtained a cut-off point of ≥4.5 for FWD. The diagnostic performance of the score was characterized by a sensitivity of 0.889, a specificity of 0.879 (P < .001). A scoring system based only on aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, AST/ALT ratio, uric acid and haemoglobin had a best cut-off point of ≥2.5 for FWD, which had a sensitivity of 0.875, a specificity of 0.867 (P < .001).

CONCLUSIONS

Our study demonstrated that biochemical markers offer almost as reliable, fast and accurate diagnosis of FWD as offered by ceruloplasmin and 24-hour urinary copper.

The Effect of Heat Stress on Autophagy and Apoptosis of Rumen, Abomasum, Duodenum, Liver and Kidney Cells in Calves

The objective of this study was to assess the effect of heat stress on the autophagy and apoptosis of the rumen, abomasum, duodenum, liver and kidney in calves. Two groups of Holstein male calves were selected with similar birth weights and health conditions. Heat stress (HT): Six calves (birth weight 42.2 ± 2.3) were raised from July 15 to August 19. Cooling (CL): Six calves (birth weight 41.5 ± 3.1 kg) were raised from April 10 to May 15. All the calves were euthanized following captive bolt gun stunning at 35 d of age. The expression of protein 1 light chain 3-Ⅱ (LC3-Ⅱ) and caspase3 in the rumen, abomasum, duodenum, liver and kidney were determined by western blotting. In addition, other possible relevant serum biochemical parameters were evaluated. Significant differences were observed in alkaline phosphatase (ALP), albumin (ALB) and glucose (Glu). The results showed that heat stress could increase the autophagy and apoptosis of the kidney, duodenum and abomasum. However, heat stress had no effect on the autophagy and apoptosis of the liver. Additionally, the expression of caspase-3 in the rumen in HT was significantly lower than that in CL. In conclusion, the effects of heat stress on autophagy and apoptosis are organ-specific. The results provide knowledge regarding autophagy and autophagy in calf heat stress management.

Bone formation and resorption markers at 7 years of age: Relations with growth and bone mineralization

Purpose

We aimed to describe bone formation and resorption markers in generally healthy prepubertal children using total alkaline phosphatase (tALP), osteocalcin (OC) and β-isomerized C-terminal telopeptides of type I collagen (β-CTx) serum concentrations and to estimate markers’ correlations with anthropometric growth (height, weight, body mass index and trajectories of weight gain) as well as bone mineral content (BMC) and areal density (aBMD).

Methods

We assessed 395 7-year-old children from the Generation XXI cohort with tALP, OC and β-CTx concentrations determined from a fasting venous blood sample and BMC/aBMD measured by dual-energy X-ray absorptiometry. Gender-specific reference intervals for tALP, OC and β-CTx in 7-year-old children were established by calculating the 2.5^th and 97.5^th percentiles. Pearson and partial correlation coefficients (controlling for sex, age, body size and season) between bone markers and growth measures were computed.

Results

tALP increased with height (r_partial controlled for sex = 0.26, 95%CI: 0.17, 0.35), was higher in overweight than in healthy weight children, and in children who gained weight above average during infancy. No correlations were found between OC or β-CTx and growth. In girls, OC was slightly correlated with subtotal BMC (r_partial = 0.22, 95%CI: 0.08, 0.35), subtotal aBMD (r_partial = 0.20, 95%CI: 0.06, 0.33) and lumbar spine aBMD (r_partial = 0.23, 95%CI: 0.09, 0.36). tALP and β-CTx were not correlated with any of the DXA-derived bone measures.

Conclusion

This study contributed to the description of bone turnover at 7 years of age and suggested that bone metabolism markers measured in a single point in time have limited ability to describe anthropometric growth and overall bone status in generally healthy prepubertal children.

Algorithm on age partitioning for estimation of reference intervals using clinical laboratory database exemplified with plasma creatinine

BACKGROUND

We describe an algorithm to determine age-partitioned reference intervals (RIs) exemplified for creatinine using data collection from the clinical laboratory database.

METHODS

The data were acquired from the test results of creatinine of 164,710 outpatients aged <18 years in Beijing Children's Hospital laboratories' databases between January 2016 and December 2016. The tendency of serum creatinine with age was examined visually using box plot by gender first. The age subgroup was divided automatically by the decision tree method. Subsequently, the statistical tests of the difference between subgroups were performed by Harris-Boyd and Lahti methods.

RESULTS

A total of 136,546 samples after data cleaning were analyzed to explore the partition of age group for serum creatinine from birth to 17 years old. The suggested age partitioning of RIs for creatinine by the decision tree method were for eight subgroups. The difference between age subgroups was demonstrated to be statistically significant by Harris-Boyd and Lahti methods. In addition, the results of age partitioning for RIs estimation were similar to the suggested age partitioning by the Canadian Laboratory Initiative in Pediatric Reference Intervals study. Lastly, a suggested algorithm was developed to provide potential methodological considerations on age partitioning for RIs estimation.

CONCLUSIONS

Appropriate age partitioning is very important for establishing more accurate RIs. The procedure to explore the age partitioning using clinical laboratory data was developed and evaluated in this study, and will provide more opinions for designing research on establishment of RIs.

Indirect determination of hematology reference intervals in adult patients on Beckman Coulter UniCell DxH 800 and Abbott CELL-DYN Sapphire devices

Background

Conventional establishment of reference intervals for hematological analytes is challenging due to the need to recruit healthy persons. Indirect methods address this by deriving reference intervals from clinical laboratory databases which contain large datasets of both physiological and pathological test results.

Methods

We used the “Reference Limit Estimator” (RLE) to establish reference intervals for common hematology analytes in adults aged 18–60 years. One hundred and ninety-five samples from 44,519 patients, measured on two different devices in a tertiary care center were analyzed. We examined the influence of patient cohorts with an increasing proportion of abnormal test results, compared sample selection strategies, explored inter-device differences, and analyzed the stability of reference intervals in simulated datasets with varying overlap of pathological and physiological test results.

Results

Reference intervals for hemoglobin, hematocrit, red cell count and platelet count remained stable, even if large numbers of pathological samples were included. Reference intervals for red cell indices, red cell distribution width and leukocyte count were sufficiently stable, if patient cohorts with the highest fraction of pathological samples were excluded. In simulated datasets, estimated reference limits shifted, if the pathological dataset contributed more than 15%–20% of total samples and approximated the physiological distribution. Advanced sample selection techniques did not improve the algorithm’s performance. Inter-device differences were small except for red cell distribution width.

Conclusions

The RLE is well-suited to create reference intervals from clinical laboratory databases even in the challenging setting of a adult tertiary care center. The procedure can be used as a complement for reference interval determination where conventional approaches are limited.

Current and Emerging Therapeutic Options for the Management of Rare Skeletal Diseases

Increasing knowledge in the field of rare diseases has led to new therapeutic approaches in the last decade. Treatment strategies have been developed after elucidation of the underlying genetic alterations and pathophysiology of certain diseases (e.g., in osteogenesis imperfecta, achondroplasia, hypophosphatemic rickets, hypophosphatasia and fibrodysplasia ossificans progressiva). Most of the drugs developed are specifically designed agents interacting with the disease-specific cascade of enzymes and proteins involved. While some are approved (asfotase alfa, burosumab), others are currently being investigated in phase III trials (denosumab, vosoritide, palovarotene). To offer a multi-disciplinary therapeutic approach, it is recommended that patients with rare skeletal disorders are treated and monitored in highly specialized centers. This guarantees the greatest safety for the individual patient and offers the possibility of collecting data to further improve treatment strategies for these rare conditions. Additionally, new therapeutic options could be achieved through increased awareness, not only in the field of pediatrics but also in prenatal and obstetric specialties. Presenting new therapeutic options might influence families in their decision of whether or not to terminate a pregnancy with a child with a skeletal disease.

Alkaline phosphatase: a potential biomarker for stroke and implications for treatment

Stroke is the fifth leading cause of death in the U.S., with more than 100,000 deaths annually. There are a multitude of risks associated with stroke, including aging, cardiovascular disease, hypertension, Alzheimer's disease (AD), and immune suppression. One of the many challenges, which has so far proven to be unsuccessful, is the identification of a cost-effective diagnostic or prognostic biomarker for stroke. Alkaline phosphatase (AP), an enzyme first discovered in the 1920s, has been evaluated as a potential biomarker in many disorders, including many of the co-morbidities associated with stroke. This review will examine the basic biology of AP, and its most common isoenzyme, tissue nonspecific alkaline phosphatase (TNAP), with a specific focus on the central nervous system. It examines the preclinical and clinical evidence which supports a potential role for AP in stroke and suggests potential mechanism(s) of action for AP isoenzymes in stroke. Lastly, the review speculates on the clinical utility of AP isoenzymes as potential blood biomarkers for stroke or as AP-targeted treatments for stroke patients.

Indirect methods for reference interval determination - review and recommendations

Reference intervals are a vital part of the information supplied by clinical laboratories to support interpretation of numerical pathology results such as are produced in clinical chemistry and hematology laboratories. The traditional method for establishing reference intervals, known as the direct approach, is based on collecting samples from members of a preselected reference population, making the measurements and then determining the intervals. An alternative approach is to perform analysis of results generated as part of routine pathology testing and using appropriate statistical techniques to determine reference intervals. This is known as the indirect approach. This paper from a working group of the International Federation of Clinical Chemistry (IFCC) Committee on Reference Intervals and Decision Limits (C-RIDL) aims to summarize current thinking on indirect approaches to reference intervals. The indirect approach has some major potential advantages compared with direct methods. The processes are faster, cheaper and do not involve patient inconvenience, discomfort or the risks associated with generating new patient health information. Indirect methods also use the same preanalytical and analytical techniques used for patient management and can provide very large numbers for assessment. Limitations to the indirect methods include possible effects of diseased subpopulations on the derived interval. The IFCC C-RIDL aims to encourage the use of indirect methods to establish and verify reference intervals, to promote publication of such intervals with clear explanation of the process used and also to support the development of improved statistical techniques for these studies.

NUMBER: standardized reference intervals in the Netherlands using a ‘big data’ approach

Background

External quality assessment (EQA) programs for general chemistry tests have evolved from between laboratory comparison programs to trueness verification surveys. In the Netherlands, the implementation of such programs has reduced inter-laboratory variation for electrolytes, substrates and enzymes. This allows for national and metrological traceable reference intervals, but these are still lacking. We have initiated a national endeavor named NUMBER (Nederlandse UniforMe Beslisgrenzen En Referentie-intervallen) to set up a sustainable system for the determination of standardized reference intervals in the Netherlands.

Methods

We used an evidence-based ‘big-data’ approach to deduce reference intervals using millions of test results from patients visiting general practitioners from clinical laboratory databases. We selected 21 medical tests which are either traceable to SI or have Joint Committee for Traceability in Laboratory Medicine (JCTLM)-listed reference materials and/or reference methods. Per laboratory, per test, outliers were excluded, data were transformed to a normal distribution (if necessary), and means and standard deviations (SDs) were calculated. Then, average means and SDs per test were calculated to generate pooled (mean±2 SD) reference intervals. Results were discussed in expert meetings.

Results

Sixteen carefully selected clinical laboratories across the country provided anonymous test results (n=7,574,327). During three expert meetings, participants found consensus about calculated reference intervals for 18 tests and necessary partitioning in subcategories, based on sex, age, matrix and/or method. For two tests further evaluation of the reference interval and the study population were considered necessary. For glucose, the working group advised to adopt the clinical decision limit.

Conclusions

Using a ‘big-data’ approach we were able to determine traceable reference intervals for 18 general chemistry tests. Nationwide implementation of these established reference intervals has the potential to improve unequivocal interpretation of test results, thereby reducing patient harm.

Distinguishing reference intervals and clinical decision limits - A review by the IFCC Committee on Reference Intervals and Decision Limits

Reference Intervals (RIs) and clinical decision limits (CDLs) are a vital part of the information supplied by laboratories to support the interpretation of numerical clinical pathology results. RIs describe the typical distribution of results seen in a healthy reference population while CDLs are associated with a significantly higher risk of adverse clinical outcomes or are diagnostic for the presence of a specific disease. However, as the two concepts are sometimes confused, there is a need to clarify the differences between these terms and to ensure they are easily distinguished, especially because CDLs have a clinical association with specific diseases and risks, thereby implying that effective clinical interventions are available. It is important to note that, because population-based RIs are derived from the range of values expected in a typical community population, laboratory results that fall outside a RI do not necessarily indicate a disease but rather that additional medical follow-up and/or treatment may be warranted. In contrast, CDLs are associated with a risk of specific adverse outcomes, and are commonly used to interpret laboratory test results, including lipid parameters, glucose, hemoglobin A1c (HbA1c), and tumor markers, to determine risk of disease, to diagnose or to treat. In recent years, the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Committee on Reference Intervals and Decision Limits (C-RIDL) has focused primarily on RIs and has performed multicenter studies to obtain common RIs. However, the broader responsibility of the Committee, from its name, includes "decision limits". C-RIDL now aims to emphasize the importance of the correct use of both RIs and CDLs and to encourage laboratories to specify the appropriate information to clinicians as needed. This review discusses RIs and CDLs in detail, describes the similarities and the differences between these two important tools in laboratory medicine, and clearly explains the processes used to define them. C-RIDL encourages the involvement of laboratory professionals in the establishment of both RIs and CDLs.

Pediatric reference intervals for general clinical chemistry components - merging of studies from Denmark and Sweden

BACKGROUND

Reference intervals are crucial tools aiding clinicians when making medical decisions. However, for children such values often are lacking or incomplete. The present study combines data from separate pediatric reference interval studies of Denmark and Sweden in order to increase sample size and to include also pre-school children who were lacking in the Danish study.

METHODS

Results from two separate studies including 1988 healthy children and adolescents aged 6 months to 18 years of age were merged and recalculated. Eighteen general clinical chemistry components were measured on Abbott and Roche platforms. To facilitate commutability, the NFKK Reference Serum X was used.

RESULTS

Age- and gender-specific pediatric reference intervals were defined by calculating 2.5 and 97.5 percentiles.

CONCLUSION

The data generated are primarily applicable to a Nordic population, but could be used by any laboratory if validated for the local patient population.

Urine Cotinine Should Be Involved in Initial Evaluation of Tinnitus in Adolescents

Objectives

Smoking is associated with hearing loss, while the correlation between tinnitus and smoking is not fully elucidated. This study aimed to evaluate risk factors of tinnitus in adolescents in terms of smoking, and we identified a rectifiable parameter that can be serially monitored.

Methods

A cross-sectional study was conducted using data from the Korea National Health and Nutrition Examination Survey, with 2,782 participants aged 12 to 18 years, from 2008 through 2011. Participants with history of ear disease, hearing loss, and inadequate responses to questionnaires were excluded. We investigated the prevalence of tinnitus and tinnitus-related annoyance by questionnaire and sought potential risk factors in blood and urine tests and smoking history.

Results

The prevalence of tinnitus in the 12- to 18-year-old population was 17.5%, with 3.3% reporting tinnitus-related annoyance. On univariate analysis, the prevalence of tinnitus increased with age (P<0.001) and was higher among girls (P=0.012). Blood tests and urinalysis showed significant correlation between tinnitus and red blood cell count, alkaline phosphatase levels, and urine cotinine (P=0.002, P<0.001, P=0.018, respectively). In multivariate analysis, the urine cotinine level was the only parameter associated with tinnitus (odds ratio, 1.000; 95% confidence interval, 0.999 to 1.000; P=0.038). Smoking was also significantly correlated with tinnitus (P=0.043), and amount of smoking with tinnitus-related annoyance (P=0.045). However, current smoking and past smoking were not correlated with tinnitus.

Conclusion

Urine cotinine may be a rectifiable marker for management of tinnitus in adolescents. This suggests that smoking cessation should be incorporated in the management of tinnitus in adolescents.

Dynamic reference intervals for coagulation parameters from infancy to adolescence

INTRODUCTION

Practical and ethical challenges as well as time and costs have restricted the generation of pediatric reference intervals. Therefore, pediatric reference intervals on coagulation parameters based on solid evidence are still scarce. Furthermore, reference intervals by age-group cannot reflect the dynamics of age and sex specific coagulation values during childhood. This study is the first to close this gap and provide continuous age and sex dependent reference intervals during childhood in hemostasis.

METHODS

We used an innovative indirect method for providing continuous reference intervals for five common coagulation parameters: Activated partial thromboplastin time (aPTT), prothrombin time (PT), thrombin clotting time (TT), fibrinogen (FIB) and antithrombin (AT). Calculations were performed using retrospective laboratory data from pediatric patients between 2005 and 2015 of two major Austrian hospitals, resulting in a total of 195.360 measurements (aPTT: 55,100; PT: 35,492; TT: 35,295; FIB: 49,789; AT: 19,684).

RESULTS

This multicenter study provides calculations of continuous reference intervals for five common coagulation parameters in a large pediatric cohort, accounting for age and gender.

CONCLUSION

To the best of our knowledge, this is the first multicenter study, determining continuous pediatric coagulation reference intervals based on a large retrospective dataset.