Robust reference intervals for liver function test (LFT) analytes in newborns and infants

Prophylactic fluconazole protocol in very low birth weight infants: invasive candidiasis prevention in a Latin American neonatal intensive care unit

OBJECTIVE

To evaluate the effect of prophylactic fluconazole for very low birth weight infants (VLBWI) in a neonatal intensive care unit (NICU) with a 7.8% incidence of invasive candidiasis (IC).

STUDY DESIGN

Interventional pre-post cohort study comparing 2 years with and without fluconazole prophylaxis protocol (2016-2018 = 228 infants and 2019-2021 = 125 infants). Fluconazole was administered to all extremely low birth weight infants (ELBWI) and infants with BW 1001-1500 g with risk factors or positive carrier cultures. Liver function tests were performed weekly.

RESULTS

The incidence of IC decreased from 7.8% to 2.4% (OR:0.3, p = 0.05) with the use of prophylactic fluconazole for VLBWI and in ELBWI decreased from 16,7% to 3,7% (OR:0.1, p = 0.04). No significant differences were seen in mortality.

CONCLUSIONS

Fluconazole is a safe, effective, and feasible strategy to prevent IC in a Latin American country.

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.

Serum Level of Alanine- and Aspartate-Aminotransferase Levels in Newborns in India

Background

Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤40 IU/L is normal. This cutoff, although determined in adults, is widely used for newborns. We studied the reference ranges for ALT and AST in newborns in India.

Methods

We prospectively included babies with gestational age (GA) between 34 and 41weeks and birth weight (BW) ≥ 1500 g. We excluded the babies who either themselves or their mother had risk factors, which could cause elevation of serum levels of liver enzymes. Serum ALT and AST were measured in venous cord blood. The estimated percentile curves for ALT and AST, for BW and GA covariates, were drawn with General Additive Model for Location Scale and Shape (GAMLSS) with Box-Cox Power Exponential (BCPE).

Results

Five-hundred thirty-seven babies (Boys 53.3%; GA 34-36 wks 19.7%; appropriate for GA 74.9%; BW < 2500 g 20.5%) were included. Overall, mean [SD] serum ALT and AST were 44¹² IU/L and 52¹⁸ IU/L, respectively. The serum AST was significantly higher than the ALT level, regardless of gender, BW, GA, or fetal growth categories. The percentile curve against GA remained flat for ALT, although it showed a slight rise for AST. Serum levels of ALT and AST plotted against BW were also similar and showed an increase up to 2000 g and then remained stationary after that.

Conclusion

The serum levels of ALT and AST up to 44 IU/L and 52 IU/L, respectively, can be taken as normal in newborns with BW ≥ 2000 g or GA ≥34 weeks.

Liver function tests and fibrosis scores in a rural population in Africa: a cross-sectional study to estimate the burden of disease and associated risk factors

OBJECTIVES

Liver disease is a major cause of morbidity and mortality in sub-Saharan Africa, but its prevalence, distribution and aetiology have not been well characterised. We therefore set out to examine liver function tests (LFTs) and liver fibrosis scores in a rural African population.

DESIGN

We undertook a cross-sectional survey of LFTs. We classified abnormal LFTs based on reference ranges set in America and in Africa. We derived fibrosis scores (aspartate aminotransferase (AST) to Platelet Ratio Index (APRI), fibrosis-4, gamma-glutamyl transferase (GGT) to platelet ratio (GPR), red cell distribution width to platelet ratio and S-index). We collected information about alcohol intake, and infection with HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV).

SETTING

We studied a population cohort in South-Western Uganda.

PARTICIPANTS

Data were available for 8099 adults (median age 30 years; 56% female).

RESULTS

The prevalence of HBV, HCV and HIV infection was 3%, 0.2% and 8%, respectively. The prevalence of abnormal LFTs was higher based on the American reference range compared with the African reference range (eg, for AST 13% vs 3%, respectively). Elevated AST/ALT ratio was significantly associated with self-reported alcohol consumption (p<0.001), and the overall prevalence of AST/ALT ratio >2 was 11% (suggesting alcoholic hepatitis). The highest prevalence of fibrosis was predicted by the GPR score, with 24% of the population falling above the threshold for fibrosis. There was an association between the presence of HIV or HBV and raised GPR (p=0.005) and S-index (p<0.001). By multivariate analysis, elevated LFTs and fibrosis scores were most consistently associated with older age, male sex, being under-weight, HIV or HBV infection and alcohol consumption.

CONCLUSIONS

Further work is required to determine normal reference ranges for LFTs in this setting, to evaluate the specificity and sensitivity of fibrosis scores and to determine the aetiology of liver disease.

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.

Incidence, Risk Factors, and Morbidity of Acquired Postnatal Cytomegalovirus Infection Among Preterm Infants Fed Maternal Milk in a Highly Seropositive Population

BACKGROUND

In preterm infants cytomegalovirus (CMV) infection acquired through maternal milk has been related to morbidity. However, infants who may receive higher titers of protective antibodies from highly seropositive mothers have not been studied in detail.

METHODS

A cohort of 188 ≤30-week-old infants was monitored from admission to discharge. CMV-DNA, hematology, liver enzymes, neutralizing antibodies, and CMV-DNA-lactia were tested periodically.

RESULTS

Mothers of 157 infants (83.5%) were CMV-seropositive. A total of 24/157 (15.3%) infants became infected (95% confidence interval [CI], 9.8-22.6), particularly those of lower gestational age (GA; relative risk [RR], 2.32; 95% CI, 1.01-5.34 for 23-26 weeks). Low (<1:64) neutralizing antibody titers were similarly detected in CMV-infected and uninfected infants. Mean DNA-lactia in mothers was higher in CMV-infected than in uninfected infants (5.34 log vs 4.60 log). Clinical findings suggestive of CMV disease were similar in CMV-infected (50.0%) and CMV-uninfected (51.1%) infants. Although transitory, >2 laboratory test abnormalities occurred more frequently among CMV-infected (39.1%) than CMV-uninfected (2.1%) infants. More severe stages of retinopathy of prematurity (ROP) were found among CMV-infected infants (adjusted RR, 2.51; 95% CI, 1.07-5.91). Although deaths were more frequent among infected infants, none of the deaths could be directly attributed to CMV.

CONCLUSIONS

Postnatal CMV infection acquired by exposure to raw maternal milk is very frequent among extremely premature newborns, being facilitated by high DNA-lactia and lower GA, regardless of maternally acquired neutralizing antibody levels. The association with advanced stages of ROP is a concern and needs to be further explored in larger studies.

Trends and physiology of common serum biochemistries in children aged 0-18 years

The aim of this study was to visually present and discuss in detail the physiological trends of 22 serum biochemistries in children aged 0-18.A data-mining, LMS (lambda, mu, and sigma) approach was employed to derive the smoothed continuous serum biochemistry centile charts, after application of stringent outlier exclusion criteria.Serum sodium and calculated osmolality are low in early life and rise with age due to maturing kidney and body water redistribution. Urea, creatinine and uric acid is high at birth, declines to reach a trough by 1 month of age and gradually rises again thereafter. Serum bicarbonate falls initially during the neonatal and toddler period, then rises with declining respiratory rate, further increasing sodium and suppressing chloride. Potassium, calcium and phosphate are required for somatic growth and are actively accrued during periods of rapid growth. Albumin increases until puberty while globulin rises to age 10 as a result of increased hepatic synthetic capacity and maturing immunity. Serum alkaline phosphatase activity peaks during bone growth spurts in infancy and adolescence due to osteoblast leakage, while creatinine increases with muscle mass. Serum gamma-glutamyl transferase, aspartate aminotransferase and lactate dehydrogenase activities are high at birth and decline with age. Serum alanine aminotransferase activity is low at birth and is induced by increased gluconeogenesis. Serum bilirubin increases continuously with age, mirroring haemoglobin concentration. Serum total cholesterol declines more markedly in boys than girls during puberty due to the combined effects of free testosterone (lowering high-density lipoprotein cholesterol in boys) and oestradiol (lowering low-density lipoprotein cholesterol in boys and girls).It is important to understand trends and biological variation when interpreting results since partitioned reference intervals may mask this information.

Establishing reference intervals for electrolytes in newborns and infants using direct ISE analyzer

BACKGROUND

To generate clinically applicable reference intervals (RIs) for commonly requested electrolytes in Ethiopian newborns and infants that can help in early detection, close monitoring and correction of electrolyte abnormalities. Cord blood (from newborns, n = 60) and venous blood samples (from infants, n = 57) were collected and analyzed using direct ISE analyzer, AVL (9181). MedCalc® software was applied to determine the robust upper and lower end points covering 95% of the reference values of each electrolyte with respective 90% CIs.

FINDINGS

This is an extension report of our recent study; and hence is resulted from the same data source. The level of Na+ and K+ showed difference in newborns and infants even though combined RIs were suggested by the Haris and Boyd rule as 126-143 mmol/l and 4.0-7.9 mmol/l respectively. However, Cl- values failed to show such a difference and thus a combined RI was determined to be 100-111 mmol/l. Almost all maternal, neonatal and infantile factors were not able to affect the values of the electrolytes.

CONCLUSION

Combined RIs are suggested for the interpretation of electrolyte values in newborns and infants without taking the effect of maternal, neonatal and infantile factors into account. Since the RIs were different from previously reported values, it will be appropriate to apply such RIs for the interpretation of electrolyte values in Ethiopian pediatric population.