Establishment of biochemistry reference values for healthy Tanzanian infants, children and adolescents in Kilimanjaro Region

Short stature with low serum alkaline phosphatase activity: a case report of hypophosphatasia

Hypophosphatasia (HPP) is a rare condition characterized by abnormal bone mineralization. The manifestations of HPP vary from no symptoms to intrauterine fetal death; short stature is another indication of HPP. A 3 ½-year-old boy presented with short stature, transient hypercalcemia, and mild gait disturbance without definite bony deformity. Laboratory examination revealed transient hypercalcemia, normal phosphorous and 25-hydroxy vitamin D levels, and mildly low alkaline phosphatase levels. A targeted next-generation sequencing panel associated with inborn errors of metabolism revealed a pathogenic heterozygous mutation in the ALPL gene, c.979T>C (p.Phe327Leu). When a child visits a hospital with short stature, decreased height velocity, and low alkaline phosphatase level, clinicians should consider the possibility of HPP even if definite skeletal dysplasia is not evident.

Region-specific laboratory reference intervals are important: A systematic review of the data from Africa

Region-specific laboratory reference intervals (RIs) are important for clinical trials and these data are often sparse in priority areas for research, including Africa. We reviewed data on RIs from Africa to identify gaps in the literature with a systematic review of PubMed for RI studies from Africa published ≥2010. Search focus included clinical analytic chemistry, hematology, immunological parameters and RIs. Data from adults, adolescents, children, pregnant women, and the elderly were included. We excluded manuscripts reporting data from persons with conditions that might preclude clinical trial participation in studies enrolling healthy volunteers. Of 179 identified manuscripts, 80 were included in this review, covering 20 countries with the largest number of studies in Ethiopia (n = 23, 29%). Most studies considered healthy, nonpregnant adults (n = 55, 69%). Nine (11%) studies included pregnant women, 13 (16%) included adolescents and 22 (28%) included children. Recruitment, screening, enrollment procedures and definition of age strata varied across studies. The most common type of RIs reported were hematology (66, 83%); 14 studies (18%) included flow cytometry and/or T cell counts. Other common tests or panels included liver function assays (32, 40%), renal function assays (30, 38%), lipid chemistries (17, 21%) and serum electrolytes (17, 21%). The number of parameters characterized ranged from only one (three studies characterized either CD4+ counts, D-dimer, or hemoglobin), to as many as 40. Statistical methods for calculating RIs varied. 56 (70%) studies compared their results to international RI databases. Though most presented their data side-by-side with international data with little accompanying analysis, nearly all reported deviation from comparator RI data, sometimes with half or more of otherwise healthy participants having an "out of range" result. We found there is limited local RI data available in sub-Saharan Africa. Studies to fill this gap are warranted, including efforts to standardize statistical methods to derive RIs, methods to compare with other RIs, and improve representative participant selection.

Rural-urban disparities in the nutritional status of younger adolescents in Tanzania

Research on geographic differences in health focuses largely on children less than five years; little is known about adolescents—and even less regarding younger adolescents—a vulnerable group at a critical stage of the life course. Africa’s rapid population growth and urbanization rates, coupled with stagnant rates of undernutrition, further indicate the need for country-specific data on rural-urban health disparities to inform development policies. This study examined rural-urban disparities in body mass index-for-age-and-sex (BAZ) and height-for-age-and-sex z-scores (HAZ) among younger adolescents in Tanzania. Participants were randomly selected adolescents aged 10–14 years (N = 1,125) residing in Kilosa (rural) and Moshi (urban) districts of Tanzania. Individual and household-level data were collected using surveys and anthropometric data was collected on all adolescents. Age, sex, household living conditions, and assets were self-reported. BAZ and HAZ were calculated using the WHO reference guide. The prevalence of undernutrition was 10.9% among rural and 5.1% among urban adolescents (p<0.001). Similarly, stunting prevalence was greater in rural (64.5%) than urban (3.1%) adolescents (p<0.001). After adjusting for covariates, rural residence was significantly and inversely associated with BAZ (B = -0.29, 95% CI: -0.52, -0.70, p = 0.01), as well as with HAZ (B = -1.79, 95% CI: -2.03, -1.54, p<0.001). Self-identified males had lower BAZ (B = -0.23, 95% CI: -0.34, -0.11, p<0.001) and HAZ (B = -0.22, 95% CI: -0.35, -0.09, p = 0.001) than self-identified female adolescents. Rural-urban disparities in nutritional status were significant and gendered. Findings confirm place of residence as a key determinant of BAZ and HAZ among younger adolescents in Tanzania. Targeted gender-sensitive interventions are needed to limit growth faltering and improve health outcomes in rural settings.

Establishment of Reference Intervals for Alkaline Phosphatase in Pakistani Children Using a Data Mining Approach

OBJECTIVE

To establish reference intervals (RIs) for alkaline phosphatase (ALP) levels in Pakistani children using an indirect data mining approach.

METHODS

ALP levels analyzed on a Siemens Advia 1800 analyzer using the International Federation of Clinical Chemistry's photometric method for both inpatients and outpatients aged 1 to 17 years between January 2013 and December 2017, including patients from intensive care units and specialty units, were retrieved. RIs were calculated using a previously validated indirect algorithm developed by the German Society of Clinical Chemistry and Laboratory Medicine's Working Group on Guide Limits.

RESULTS

From a total of 108,845 results, after the exclusion of patients with multiple specimens, RIs were calculated for 24,628 males and 18,083 females with stratification into fine-grained age groups. These RIs demonstrate the complex age- and sex-related ALP dynamics occurring during physiological development.

CONCLUSION

The population-specific RIs serve to allow an accurate understanding of the fluctuations in analyte activity with increasing age and to support clinical decision making.

Dyslipidemia in HIV-Infected Children and Adolescents on Antiretroviral Therapy Receiving Care at Kilimanjaro Christian Medical Centre in Tanzania: A Cross-Sectional Study

Background:

Worldwide prevalence of dyslipidemia in HIV-infected children on antiretroviral medications (ARVs) is rising due to extensive use of treatment during their entire lives. Dyslipidemia is the potential side effect of ARVs, especially in individuals taking protease inhibitors. The objective of this study was to determine the prevalence of dyslipidemia in HIV-infected children on ARVs receiving care at Kilimanjaro Christian Medical Centre (KCMC) in Tanzania.

Methods:

This was a cross-sectional hospital-based study conducted from September 2015 to May 2016 at KCMC. HIV-infected children and adolescents less than 17 years on ARVs for more than 6 months were enrolled. Blood samples were taken to determine levels of triglycerides (TGs), total cholesterol, lipoproteins (including low-density lipoprotein (LDL) and high-density lipoprotein (HDL)), CD4+ T cells, and viral load (VL). Anthropometric measurements were used to assess nutritional status. SPSS 20.0 was used for analysis. Logistic regression estimated odds ratio (OR) and 95% confidence interval (CI), and P value <.05 was considered significant. Written consent was obtained from parents/guardians on behalf of their children and assent for older children.

Results:

A total of 260 participants were included in the study; the median age at HIV diagnosis was 3 (interquartile range (IQR) = 1-6) years. The overall prevalence of dyslipidemia was 46.5% with hypercholesterolemia (⩾200 mg/dl) of 11.2%, HDL (<35 mg/dl) of 22.7%, LDL (⩾130 mg/dl) of 7.7%, and hyperglyceridemia (TG ⩾150 mg/dl) of 12.3%. Children aged between 6 and 12 years at HIV diagnosis had 2.7 times higher odds of developing dyslipidemia compared with younger age at diagnosis (OR = 2.7; 95% CI = 1.1-6.6). Patients with advanced (OR = 6.4; 95% CI = 1.5-27.1) or severe (OR = 9.8; 95% CI = 1.2-76.5) HIV-associated immunodeficiency at diagnosis had higher odds of developing dyslipidemia. Protease inhibitor use was associated with higher odds of developing dyslipidemia (OR = 3.1; 95% CI = 1.4-7.1).

Conclusion:

Late diagnosis of HIV at 6 years of age or more, advanced, or severe immunosuppression, and the use of protease inhibitors were independent predictors of dyslipidemia in children on ARVs after 6 months of treatment, and with low HDL levels observed most commonly. Monitoring lipid profiles in children, especially those on protease inhibitors and with advanced/severe immunosuppression at diagnosis, may help in preventing future complications.

Electrocardiographic safety evaluation of extended artemether-lumefantrine treatment in patients with uncomplicated Plasmodium falciparum malaria in Bagamoyo District, Tanzania

Background

Extended artemisinin-based combination therapy (ACT) for treatment of uncomplicated Plasmodium falciparum malaria with already existing drug regimens, such as artemether-lumefantrine, might be effective in tackling the emerging ACT resistance. However, given the history of cardiotoxicity among anti-malarial drugs structurally similar to lumefantrine, the potential effect of extended artemether-lumefantrine treatment on the electrocardiographic (ECG) QTc interval is of high concern.

Methods

Male and non-pregnant females aged 1–65 years, diagnosed with uncomplicated P. falciparum malaria in Bagamoyo district, Tanzania, were randomized into two arms. The intervention arm received an extended, i.e. 6-day, course of artemether-lumefantrine and an additional single low-dose primaquine (0.25 mg/kg) administered together with the last artemether-lumefantrine dose. The control arm received the standard weight-based 3-day course. ECGs were performed at day 0 and 4–5 h after the last dose at day 5. QT intervals were read manually using the tangent method and automatically. Bazett’s (QTcB) and Fridericia’s (QTcF) formulae were used for correction for heart rate. Descriptive statistics were used to calculate baseline characteristics and the number of supra-thresholds QTc intervals (QTc prolongation > 500, change in QTc interval (ΔQTc) > 60 ms). The mean change in QTc interval in and between the two arms was compared using the paired t-test and independent samples t-test, respectively.

Results

A total of 195 patients were enrolled, 103 and 92 in the intervention and control arm, respectively. No patient experienced QTc intervals > 500 ms on day 5 by both formulae. Patients with ΔQTc > 60 ms, for QTcF were 6/103 (5.8%) vs 2/92 (2.2%) and for QTcB 2/103 (1.9%) vs 1/92 (1.1%) in the intervention and control arms, respectively. The mean difference in ΔQTc interval was statistically significant between the two arms with both correction formulae, 11.4 ms (95% CI 2.7–20.0, p = 0.010) and 13.4 ms (95% CI 5.3–21.5, p = 0.001), for QTcB and QTcF, respectively.

Conclusion

The extended 6-day course of artemether-lumefantrine did not reveal clinically relevant QTc prolonging effects. However, significant QTcF prolongation and presence of patients with supra-threshold QTc values observed in the intervention arm underscore the importance of further monitoring of QTc parameters in extended artemether-lumefantrine treatment.

Trial registration ClinicalTrials.gov, NCT03241901. Registered July 27, 2017. https://clinicaltrials.gov/show/NCT03241901

Parasite clearance, cure rate, post-treatment prophylaxis and safety of standard 3-day versus an extended 6-day treatment of artemether-lumefantrine and a single low-dose primaquine for uncomplicated Plasmodium falciparum malaria in Bagamoyo district, Tanzania: a randomized controlled trial

Background

Artemisinin-based combination therapy (ACT) resistant Plasmodium falciparum represents an increasing threat to Africa. Extended ACT regimens from standard 3 to 6 days may represent a means to prevent its development and potential spread in Africa.

Methods

Standard 3-day treatment with artemether–lumefantrine (control) was compared to extended 6-day treatment and single low-dose primaquine (intervention); in a randomized controlled, parallel group, superiority clinical trial of patients aged 1–65 years with microscopy confirmed uncomplicated P. falciparum malaria, enrolled in Bagamoyo district, Tanzania. The study evaluated parasite clearance, including proportion of PCR detectable P. falciparum on days 5 and 7 (primary endpoint), cure rate, post-treatment prophylaxis, safety and tolerability. Clinical, and laboratory assessments, including ECG were conducted during 42 days of follow-up. Blood samples were collected for parasite detection (by microscopy and PCR), molecular genotyping and pharmacokinetic analyses. Kaplan–Meier survival analyses were done for both parasite clearance and recurrence.

Results

A total of 280 patients were enrolled, 141 and 139 in the control and intervention arm, respectively, of whom 121 completed 42 days follow-up in each arm. There was no difference in proportion of PCR positivity across the arms at day 5 (80/130 (61.5%) vs 89/134 (66.4%), p = 0.44), or day 7 (71/129 (55.0%) vs 70/134 (52.2%), p = 0.71). Day 42 microscopy determined cure rates (PCR adjusted) were 97.4% (100/103) and 98.3% (110/112), p = 0.65, in the control and intervention arm, respectively. Microscopy determined crude recurrent parasitaemia during follow-up was 21/121 (17.4%) in the control and 14/121 (11.6%) in the intervention arm, p = 0.20, and it took 34 days and 42 days in the respective arms for 90% of the patients to remain without recurrent parasitaemia. Lumefantrine exposure was significantly higher in intervention arm from D3 to D42, but cardiac, biochemical and haematological safety was high and similar in both arms.

Conclusion

Extended 6-day artemether–lumefantrine treatment and a single low-dose of primaquine was not superior to standard 3-day treatment for ACT sensitive P. falciparum infections but, importantly, equally efficacious and safe. Thus, extended artemether–lumefantrine treatment may be considered as a future treatment regimen for ACT resistant P. falciparum, to prolong the therapeutic lifespan of ACT in Africa.

Trial registration ClinicalTrials.gov, NCT03241901. Registered July 27, 2017 https://clinicaltrials.gov/show/NCT03241901

Assessment and Interpretation of Vitamin and Trace Element Status in Sick Children: A Position Paper From the European Society for Paediatric Gastroenterology Hepatology, and Nutrition Committee on Nutrition

Assessment of vitamin and trace element status (VTE) is important in the clinical management of the sick child. In this position paper, we present the various assessment methods available to the clinical practitioner, and critically discuss pitfalls with interpretation of their results. There are 4 main approaches to assess the VTE body status of an individual patient including clinical examination, dietary assessment, and measurement of direct and indirect biomarkers of VTE in biological samples. Clinical signs of VTE deficiencies usually present only when body stores are substantially depleted and are often difficult to detect or differentiate from other nonnutrient-related causes. In isolation, dietary assessment of micronutrients can be inaccurate and imprecise, in disease and in individual patient assessment but may be useful to complement findings from other VTE assessment methods. Use of biomarkers is the most common approach to assess VTE status in routine practice but in the presence of systemic inflammatory response and in the absence of appropriate paediatric reference intervals, interpretation of biomarker results might be challenging and potentially mislead clinical practice. The use of a multimodal approach, including clinical examination, dietary assessment, and laboratory biomarkers is proposed as the optimal way to ascertain the VTE status of individual patients. In the presence of acute inflammatory conditions, VTE measurements in plasma should be replaced by biomarkers not affected by systemic inflammatory response or delayed until inflammatory state is resolved.

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 intervals of routine clinical chemistry parameters among apparently healthy young adults in Amhara National Regional State, Ethiopia

Background

Clinical laboratory reference intervals (RIs) are essential for clinical diagnosis, treatment and therapeutic monitoring. Locally established RIs are required to correctly interpret clinical laboratory results. In Ethiopia, clinical laboratory test results are interpreted based on RIs derived from a western population.

Methods

A multicenter cross-sectional study was conducted among blood donors in Amhara National Regional State, Ethiopia from March 2016 to May 2017. A total of 1,175 apparently healthy study participants were included in the study from four blood banks in the region. All clinical chemistry parameters were analyzed using Mindray BS-200E full automated clinical chemistry analyzer. The 95% RIs were estimated using reference limits at 2.5th percentile for the lower reference limit and 97.5th percentile for the upper reference limit. Kolmogorov–Sminorv and Wilcoxon rank-sum tests were used to check data distribution normality and whether partitions were needed between variables, respectively.

Results

RIs established include: ALT 5.13–42.88 U/L for males and 4.3–37 U/L for females; AST 12.13–46.88 for males and 10–43.8 U/L for females; ALP 77.2–475.8 U/L for males and 89–381 U/L for females; amylase 29–309.8 U/L for males and 29–287.9 U/L for females; GGT 7–69.8 U/L for males and 6–39.1 U/L for females; total bilirubin 0.11–1.18 mg/dl for males and 0.08–0.91 mg/dl for females; creatinine 0.48–1.13 mg/dl for males and 0.47–1.09 mg/dl for females; total cholesterol 78.13–211.75 mg/dl for males and 83.6–202.7 mg/dl for females; total protein 5.7–9.7 g/dl for males and 5.6–9.47 for females; triglycerides 36–221.9 mg/dl for males and 35.3–201.5 mg/dl for females; urea 12–43 mg/dl for males and 10–38.7 mg/dl for females; and uric acid 2.7–6.9 mg/dl for males and 2.1–5.9 mg/dl for females.

Conclusion

This study has established RIs for routine clinical chemistry parameters. These RIs are important as they support the interpretation of clinical laboratory results for medical decision making and other health-related activities.

Early Life Interventions for Childhood Growth and Development in Tanzania (ELICIT): a protocol for a randomised factorial, double-blind, placebo-controlled trial of azithromycin, nitazoxanide and nicotinamide

INTRODUCTION

In many developing areas in the world, a high burden of enteric pathogens in early childhood are associated with growth deficits. The tryptophan-kynurenine-niacin pathway has been linked to enteric inflammatory responses to intestinal infections. However, it is not known in these settings whether scheduled antimicrobial intervention to reduce subclinical enteric pathogen carriage or repletion of the tryptophan-kynurenine-niacin pathway improves linear growth and development.

METHODS AND ANALYSIS

We are conducting a randomised, placebo-controlled, factorial intervention trial in the rural setting of Haydom, Tanzania. We are recruiting 1188 children within the first 14 days of life, who will be randomised in a 2×2 factorial design to administration of antimicrobials (azithromycin and nitazoxanide, randomised together) and nicotinamide. The nicotinamide is administered as a daily oral dose, which for breast-feeding children aged 0-6 months is given to the mother and for children aged 6-18 months is given to the child directly. Azithromycin is given to the child as a single oral dose at months 6, 9, 12 and 15; nitazoxanide is given as a 3-day course at months 12 and 15. Mother/child pairs are followed via monthly in-home visits. The primary outcome is the child's length-for-age Z-score at 18 months. Secondary outcomes for the child include additional anthropometry measures; stool pathogen burden and bacterial microbiome; systemic and enteric inflammation; blood metabolomics, growth factors, inflammation and nutrition; hydrogen breath assessment to estimate small-intestinal bacterial overgrowth and assessment of cognitive development. Secondary outcomes for the mother include breastmilk content of nicotinamide, other vitamins and amino acids; blood measures of tryptophan-kynurenine-niacin pathway and stool pathogens.

ETHICS AND DISSEMINATION

This trial has been approved by the Tanzanian National Institute for Medical Research, the Tanzanian FDA and the University of Virginia IRB. Findings will be presented at national and international conferences and published in peer-review journals.

PROTOCOL VERSION

5.0, 4 December 2017.

PROTOCOL SPONSOR

Haydom Lutheran Hospital, Haydom, Manyara, Tanzania.

TRIAL REGISTRATION NUMBER

NCT03268902; Pre-results.

Establishment of Reference Interval for Alkaline Phosphatase in Healthy Children of Various Ethnicities, Aged 0-12 Years

Background

To establish a reference interval of alkaline phosphatase for healthy children of various ethnicities, aged 0 years to 12 years in China.

Methods

According to the Clinical and Laboratory Standards Institute guideline C28-A3, blood specimens were collected in the morning after overnight fasting from 502 healthy children to determine the alkaline phosphatase (ALP) level, using the Beckman AU5800 automatic biochemical analyzer. Children were grouped by sex and age. The age groups were as follows: 0 to 1 year, 1 to 3 years, 3 to 6 years, and 6 to 12 years.

Results

There were no significant differences between the sex and age groups for the age groups of 0 to 1 year, 1 to 3 years, and 3 to 6 years; as a result, we combined those groups into a single group. The reference interval of ALP is 81.9 to 350.3 U per L in the group aged 0 to 6 years and 48.8 to 445.9 U per L in the group aged 6 to 12 years.

Conclusions

The results of this study establish a reference interval for ALP in healthy children, which will provide a basis for screening, diagnosing, and monitoring bone or liver-related diseases in children.

Pediatric reference intervals for alkaline phosphatase

BACKGROUND

Interpretation of alkaline phosphatase activity in children is challenging due to extensive changes with growth and puberty leading to distinct sex- and age-specific dynamics. Continuous percentile charts from birth to adulthood allow accurate consideration of these dynamics and seem reasonable for an analyte as closely linked to growth as alkaline phosphatase. However, the ethical and practical challenges unique to pediatric reference intervals have restricted the creation of such percentile charts, resulting in limitations when clinical decisions are based on alkaline phosphatase activity.

METHODS

We applied an indirect method to generate percentile charts for alkaline phosphatase activity using clinical laboratory data collected during the clinical care of patients. A total of 361,405 samples from 124,440 patients from six German tertiary care centers and one German laboratory service provider measured between January 2004 and June 2015 were analyzed. Measurement of alkaline phosphatase activity was performed on Roche Cobas analyzers using the IFCC's photometric method.

RESULTS

We created percentile charts for alkaline phosphatase activity in girls and boys from birth to 18 years which can be used as reference intervals. Additionally, data tables of age- and sex-specific percentile values allow the incorporation of these results into laboratory information systems.

CONCLUSIONS

The percentile charts provided enable the appropriate differential diagnosis of changes in alkaline phosphatase activity due to disease and changes due to physiological development. After local validation, integration of the provided percentile charts into result reporting facilitates precise assessment of alkaline phosphatase dynamics in pediatrics.