Plasma alpha fetoprotein reference ranges in infancy: effect of prematurity

Relationship Between Total Parenteral Nutrition, Ventilation, and Hepatoblastoma: A Study of 258,929 Neonatal Intensive Care Unit Admissions

INTRODUCTION

Gestational age, low birth weight, and overgrowth syndromes are associated with the diagnosis of hepatoblastoma. Previous studies have come to mixed conclusions regarding the contribution of other neonatal intensive care unit (NICU) exposures to hepatoblastoma development. We hypothesized that total parenteral nutrition (TPN) and mechanical ventilation during index NICU admission would correlate with the development of hepatoblastoma.

METHODS

The Pediatric Health Information System (PHIS) was queried for all infants admitted to the NICU with birthdates between 2016 and 2022. From this set, patients subsequently admitted to a PHIS hospital between 2016 and 2023 with a diagnosis code for hepatoblastoma were identified. Billing information was used to calculate the number of days of TPN and mechanical ventilation exposure during NICU hospitalization.

RESULTS

A total of 258,929 patients were included, with 51 patients diagnosed with hepatoblastoma. Patients with any duration of TPN (OR = 8.51, 95% CI 4.00-18.09) or mechanical ventilation (OR = 8.21, 95% CI 4.30-15.69) developed hepatoblastoma more frequently. Matched conditional logistic regression, on gestational age and birth weight, showed a significant increase in hepatoblastoma for each additional 10 days of TPN (OR = 1.25, 95% CI 1.06-1.50) and mechanical ventilation (OR = 1.21, 95% CI 1.06-1.39).

DISCUSSION

Leveraging the magnitude of the PHIS, we were able to demonstrate a significant relationship between the duration of exposure to both TPN and mechanical ventilation and the later diagnosis of hepatoblastoma. Although the PHIS lacks granularity in reporting clinical characteristics (e.g., mode and concentration of oxygen delivery and composition of TPN) of these common NICU interventions, future investigations should be directed at the role they may play in hepatoblastoma oncogenesis.

Development of the Serum α-Fetoprotein Reference Range in Patients with Beckwith-Wiedemann Spectrum

OBJECTIVE

To establish reference ranges for serum α-fetoprotein (AFP) at various ages in patients with Beckwith-Wiedemann spectrum (BWSp), to better predict the risk for hepatoblastoma in this population.

STUDY DESIGN

A retrospective analysis of AFP measurements collected from patients with BWSp was performed. Factors including sex, prematurity, molecular diagnosis of patients, and performing laboratory were evaluated for significant differences. In total, 1372 AFP values were collected from 147 patients and the predictive AFP values at various ages were calculated to establish reference ranges. Mixed-effects polynomial regression models were used to study various potential factors affecting log(AFP) values.

RESULTS

Overall, predicted AFP values declined to normal range for age (<10 ng/mL) by 14 months old. Patient sex and performing laboratory were found not to influence values. A significant difference was demonstrated between premature and nonpremature patients, and separate reference values were established. Significant differences in the predicted AFP value were not broadly apparent between molecular subtypes; however, interpretation was limited due to the small sample size of some of these subtypes.

CONCLUSIONS

Predictive AFP values were created for premature and nonpremature patients with BWSp to aid with interpretation and monitoring of the risk for hepatoblastoma. Further analysis is needed to determine whether AFP values differ within the less common molecular subtypes of patients with BWSsp.

Longitudinal Monitoring of Alpha-Fetoprotein by Dried Blood Spot for Hepatoblastoma Screening in Beckwith⁻Wiedemann Syndrome

BACKGROUND

Hepatoblastoma screening in the Beckwith⁻Wiedemann spectrum (BWSp) is currently based on measuring a specific serum marker alpha-fetoprotein (αFP) every three months until the fourth birthday. Frequent blood draws can be a burden for patients and their families.

METHODS

We have developed a less invasive alternative testing method based on measuring αFPs from dried blood spots (DBS). The method was validated with 259 simultaneous plasma and DBS αFP measurements in 171 children (132 controls and 39 patients with BWSp).

RESULTS

The DBS and plasma measurements overlapped across the wide range of αFP concentrations independent of patient age (p < 0.0001), demonstrating the utility of this method for longitudinal monitoring. Occasional differences between measurements by the two techniques fell within standard laboratory error and would not alter clinical management.

CONCLUSIONS

This novel method shows consistent overlap with the traditional blood draws, thereby demonstrating its utility for hepatoblastoma screening in this setting and alleviating the burden of frequent blood draws. This also may help increase patient compliance and reduce costs of health care screening. The DBS-based method for the measurement of cancer biomarkers may also be applied to several other chronic diseases with increased risks of αFP-producing liver tumors.

Diagnosis and Management of Beckwith-Wiedemann Syndrome

Beckwith-Wiedemann syndrome (BWS) is a human genomic imprinting disorder that presents with a wide spectrum of clinical features including overgrowth, abdominal wall defects, macroglossia, neonatal hypoglycemia, and predisposition to embryonal tumors. It is associated with genetic and epigenetic changes on the chromosome 11p15 region, which includes two imprinting control regions. Here we review strategies for diagnosing and managing BWS and delineate commonly used genetic tests to establish a molecular diagnosis of BWS. Recommended first-line testing assesses DNA methylation and copy number variation of the BWS region. Tissue mosaicism can occur in patients with BWS, posing a challenge for genetic testing, and a negative test result does not exclude a diagnosis of BWS. Further testing should analyze additional tissue samples or employ techniques with higher diagnostic yield. Identifying the BWS molecular subtype is valuable for coordinating patient care because of the (epi)genotype-phenotype correlations, including different risks and types of embryonal tumors.

Serum α-fetoprotein in pediatric oncology: not a children’s tale

Background

Measurement of α-fetoprotein (AFP) concentrations in the serum of infants is useful for the management of testicular germ cell tumors, hepatoblastoma and hepatocellular carcinoma. Here, we provide a critical review of the available information about pediatric reference intervals (RI), focusing on their utility in interpreting AFP as an aid for cancer diagnosis.

Content

Evidence sources in the available literature were critically appraised. Out of 3873 retrieved papers, 24 were finally selected and carefully inspected, and six of them overcame exclusion criteria (i.e. methodological limitations in the study design, statistical gaps, drawbacks in traceability of the AFP assay to higher order materials and/or biased reporting of AFP results). Preterm and term infants up to the 3rd month of life exhibited the highest average AFP concentrations, but the attempt of defining RI by data pooling and partitioning for age intervals was impeded by the wide variability of data. The inability of defining robust RI in the first months of life made difficult, if not impossible, using upper reference limits for ruling out malignancies with a single AFP result. Evaluating the behavior of AFP concentrations 5 days from the baseline result, if this exceeds risk thresholds partitioned for age, according to the formula Xt=X0*2−t/HL (where: t=days elapsed for AFP retest; HL=AFP half-life according to age; X0=AFP baseline concentration, and Xt=predicted AFP concentration at day 5), could give a better information.

Summary

Novel studies defining AFP RI in infants based on robust methodology are warranted to improve the interpretation of AFP results in pediatric oncology. In the meantime, algorithms based on both serum AFP absolute concentrations and HL may aid in cancer diagnosis.

Surveillance Recommendations for Children with Overgrowth Syndromes and Predisposition to Wilms Tumors and Hepatoblastoma

A number of genetic syndromes have been linked to increased risk for Wilms tumor (WT), hepatoblastoma (HB), and other embryonal tumors. Here, we outline these rare syndromes with at least a 1% risk to develop these tumors and recommend uniform tumor screening recommendations for North America. Specifically, for syndromes with increased risk for WT, we recommend renal ultrasounds every 3 months from birth (or the time of diagnosis) through the seventh birthday. For HB, we recommend screening with full abdominal ultrasound and alpha-fetoprotein serum measurements every 3 months from birth (or the time of diagnosis) through the fourth birthday. We recommend that when possible, these patients be evaluated and monitored by cancer predisposition specialists. At this time, these recommendations are not based on the differential risk between different genetic or epigenetic causes for each syndrome, which some European centers have implemented. This differentiated approach largely represents distinct practice environments between the United States and Europe, and these guidelines are designed to be a broad framework within which physicians and families can work together to implement specific screening. Further study is expected to lead to modifications of these recommendations. Clin Cancer Res; 23(13); e115-e22. ©2017 AACRSee all articles in the online-only CCR Pediatric Oncology Series.

Serum α-fetoprotein concentration in extremely low-birthweight infants

BACKGROUND

Extremely low-birthweight infants (ELBWI) are at greater risk of developing hepatoblastoma than are normal-weight infants. Serum α-fetoprotein (AFP) plays an important role as a tumor marker in the diagnosis of hepatoblastoma, therefore the aim of this study was to determine the changes in serum AFP concentration after birth in ELBWI.

METHODS

Data were obtained for infants born between January 2005 and March 2008 with birthweight <1000 g who were followed up at Gunma Children's Medical Center with clinical examinations, including monitoring of the development of hepatoblastoma. The relationship between serum AFP concentration and age was analyzed up to 730 days after birth.

RESULTS

Overall, 95 serum AFP measurements were obtained from 23 infants 30-730 days of age, with gestational age 24-32 weeks, and birthweight 498-982 g. Log₁₀ (AFP [ng/mL]) was significantly correlated with log₁₀ (age [days]) (r = -0.961, P = 0.000, n = 95), with the following regression formula: log₁₀ (AFP [ng/mL]) = 11.063 - 3.752 log₁₀ (age [days]) (adjusted R²  = 0.923, n = 95). The standard error of the estimate, mean log₁₀ (age [days]), and the sum of squares for log₁₀ (age [days]) were 0.363, 2.503, and 10.579, respectively.

CONCLUSIONS

A correlation was found between serum AFP concentration and age in ELBWI, and the 95%CI of serum AFP concentration was determined for ELBWI up to 2 years after birth.

Metabolomic and proteomic analysis of serum from preterm infants with necrotising entercolitis and late-onset sepsis

BACKGROUND

Necrotising enterocolitis (NEC) and late-onset sepsis (LOS) are the leading causes of death among preterm infants in the developed world. This study aimed to explore the serum proteome and metabolome longitudinally in preterm infants with NEC or LOS, matched to controls.

METHODS

Nineteen patients (10 cases, 9 controls) were included. A sample 14 d prior to and following, as well as at disease diagnosis, was included for cases. Controls had serum matched at diagnosis for corresponding case. All samples (n = 39) underwent shotgun proteomic analysis, and 37 samples also underwent metabolomics analysis using ultra performance liquid chromatography-tandem mass spectrometry.

RESULTS

The proteomic and metabolomic profiles of serum were comparable between all infants. Eight proteins were associated with NEC and four proteins were associated with LOS. C-reactive protein was increased in all NEC patients at diagnosis.

CONCLUSION

No single protein or metabolite was detected in all NEC or LOS cases which was absent from controls; however, several proteins were identified which were associated with disease status. The differing expression of these proteins between diseased infants potentially relates to differing pathophysiology of disease. Thus, it is unlikely a single biomarker exists for NEC and/or LOS.

α-Fetoprotein assay on dried blood spot for hepatoblastoma screening in children with overgrowth-cancer predisposition syndromes

BACKGROUND

Beckwith-Wiedemann syndrome (BWS) and hemihyperplasia (HH) are overgrowth conditions with predisposition to hepatoblastoma for which early diagnosis patients undergo cancer screening based on determination of the tumor marker α-fetoprotein (αFP). Repeated blood draws are a burden for patients with consequent compliance issues and poor adherence to surveillance protocol. We sought to analyze feasibility and reliability of αFP dosage using an analytical micromethod based on blood dried on filter paper (DBS).

METHODS

Overall 143 coupled αFP determinations on plasma and DBS collected simultaneously were performed, of which 31 were in patients with hepatoblastoma predisposition syndromes and 112 were in controls. The plasma αFP dosage method was adapted to DBS adsorbed on paper matrix for newborn screening.

RESULTS

There was strong correlation between plasmatic and DBS αFP (r2 = 0.999, P < 0.001). Cohen's k coefficient for correlation was 0.96 for diagnostic cut-off of 10 U/ml (P < 0.001), commonly employed in clinical practice. The measurements on plasma and DBS were highly overlapping and consistent.

CONCLUSION

The DBS method allowed to dose αFP reliably and consistently for the concentrations commonly employed in clinical settings for the screening of hepatoblastoma, opening new scenarios about conducting cancer screening in overgrowth syndromes.

Clinical features of three girls with mosaic genome-wide paternal uniparental isodisomy

Here we describe three subjects with mosaic genome-wide paternal uniparental isodisomy (GWpUPD) each of whom presented initially with overgrowth, hemihyperplasia (HH), and hyperinsulinism (HI). Due to the severity of findings and the presence of additional features, SNP array testing was performed, which demonstrated mosaic GWpUPD. Comparing these individuals to 10 other live-born subjects reported in the literature, the predominant phenotype is that of pUPD11 and notable for a very high incidence of tumor development. Our subjects developed non-metastatic tumors of the adrenal gland, kidney, and/or liver. All three subjects had pancreatic hyperplasia resulting in HI. Notably, our subjects to date display minimal features of other diseases associated with paternal UPD loci. Both children who survived the neonatal period have displayed near-normal cognitive development, likely due to a favorable tissue distribution of the mosaicism. To understand the range of UPD mosaicism levels, we studied multiple tissues using SNP array analysis and detected levels of 5-95%, roughly correlating with the extent of tissue involvement. Given the rapidity of tumor growth and the difficulty distinguishing malignant and benign tumors in these GWpUPD subjects, we have utilized increased frequency of ultrasound (US) and alpha-fetoprotein (AFP) screening in the first years of life. Because of a later age of onset of additional tumors, continued tumor surveillance into adolescence may need to be considered in these rare patients.

Rapidly growing mature retroperitoneal teratomas

Retroperitoneal mature teratomas are rare benign tumors, most commonly found in neonates and young adults. We report 2 cases of fast-growing retroperitoneal mature teratomas. Both patients were girls operated on before the age of 6 months. In both cases, during the delay between diagnosis and surgery, the tumors practically doubled in size every 10 days. We believe the possibility of rapid growth of these tumors implies that treatment should be conducted as soon as possible.

Extreme levels of alpha-fetoprotein in a newborn with a benign intrapericardial teratoma

We report a neonate presenting with an intrapericardial benign teratoma and an exceptionally high level of alpha-fetoprotein. Such severe elevation of alpha-fetoprotein in a neonate with a teratoma is usually associated with the presence of immature or malignant elements, compromising the prognosis. The tumour in our patient, however, proved to be completely benign. We discuss recent findings with regard to normal levels of alpha-fetoprotein levels in preterm infants, and in children with neonatal teratomas.

Intrahepatic hematoma: hepatic lesion in a newborn with high alpha-fetoprotein level

Hepatic hematomas are relatively common in fetuses and neonates; most are subcapsular in location. Sometimes their imaging features can be non-specific, so differentiation from other aggressive lesions like hepatoblastoma can be difficult, especially if there is a concurrent high alpha-fetoprotein level. We report a case of intrahepatic hematoma with a rising alpha-fetoprotein level.

Alpha-fetoprotein in the early neonatal period—a large study and review of the literature

BACKGROUND

Alpha-fetoprotein (AFP) is a glycoprotein molecule, which has similarity to albumin and is produced by the fetal liver. Its biological role is unclear and factors that may influence its concentrations in neonates are only partially identified. However, it has an important role as a diagnostic marker, especially in certain tumors and liver diseases of childhood. Its normal reference values in newborns have not been well defined.

METHODS

Serum AFP concentrations were measured and characterized in 260 term and near-term newborns [gestational age (GA)> or =34 weeks, birthweight (BW)> or =1700 g] at birth [umbilical cord (UC) blood] and upon discharge from the nursery at 60+/-24 h of life (venous sample).

RESULTS

Due to the nonnormal distribution of AFP levels, it is useful to relate to reference interval for AFP concentrations at birth that was 15.7-146.5 microg/ml, based on 95% confidence interval (CI). The median value of 48.3 microg/ml is also a useful reference. However, mean AFP concentrations at birth that were 61.6+/-44.8 microg/ml are less informative due to the large standard deviation (S.D.). Upon discharge, AFP concentrations dropped to 9.7-111.9 microg/ml (95% CI) with a median of 34.2 microg/ml. A significant negative correlation was found between AFP serum levels and gestational age and to a lesser extent with birthweight. No significant differences were found between males and females.

CONCLUSIONS

Normal reference intervals for AFP in term and near-term newborns have been defined, but need to be addressed with caution due to the wide range of normal values. AFP levels at birth decrease as gestation advances and the newborn weighs more.

Prenatal trisomy 21 screening using the Lens culinaris agglutinin-reactive alpha-fetoprotein ratio

For the purpose of improving the clinical efficacy of alpha-fetoprotein (AFP)-L3% in prenatal screening for trisomy 21, we calculated the multiple of the median (MoM) of AFP-L3% (L3 MoM) and the ratio of L3 MoM to AFP MoM (L3 MoM/AFP MoM) in maternal serum. Maternal serum samples from 1822 women (maternal age 37.3 +/- 3.8 years, and weeks of gestation 16.0 +/- 1.0; mean +/- SD) with unaffected pregnancies and 28 women (37.6 +/- 4.6 years, 16.6 +/- 3.1) pregnant with of trisomy 21 fetuses were obtained. The AFP concentration and AFP-L3% in maternal serum were measured using a liquid-phase binding assay. The areas under the receiver operating characteristic curves (AUCs) of AFP MoM, AFP-L3%, L3 MoM, and L3 MoM/AFP MoM were 0.750, 0.868, 0.949 and 0.946, respectively. The AUCs of L3 MoM and L3 MoM/AFP MoM were significantly higher than AFP-L3% (P < 0.05) and AFP MoM (P < 0.0005). However, no statistical difference was observed between the AUCs of L3 MoM and L3 MoM/AFP MoM. In conclusion, the L3 MoM should be an effective replacement for AFP-L3% in prenatal trisomy 21 screening.

Lens culinaris agglutinin-reactive alpha-fetoprotein, an alternative variant to alpha-fetoprotein in prenatal screening for Down's syndrome

BACKGROUND

Three serum tests, alpha-fetoprotein (AFP), human chorionic gonadotrophin and unconjugated oestriol, are now widely used for screening for Down's syndrome. Lens culinaris agglutinin-reactive alpha-fetoprotein (AFP-L3) is a variant of alpha-fetoprotein with alpha1-->6 fucose appended to the reducing terminal N-acetylglucosamine. It is the most prominent AFP detected in the serum of patients with hepatocellular carcinoma.

METHODS

We investigated microheterogeneities of the carbohydrate chain on AFP in fetal liver tissues, amniotic fluids and maternal sera obtained from pregnancies with Down's syndrome using lectin affinity electrophoresis with four lectins. The percentages of AFP-L3 in maternal sera from 22 Down's syndrome and 227 unaffected pregnancies were determined.

RESULTS

Unlike the case with AFP concentration, the percentage of AFP-L3 in maternal serum and amniotic fluid was similar, and apparently not influenced by membrane permeability. Knowing the percentage of AFP-L3 in maternal serum was effective for discriminating between Down's syndrome-affected pregnancies and unaffected pregnancies. The percentage of AFP-L3 in maternal serum identified 55% of Down's syndrome cases with a 5% false-positive rate.

CONCLUSIONS

AFP-L3 should be an effective replacement for AFP in prenatal Down's syndrome screening.

Precocious pseudopuberty due to a granulosa cell tumour in a seven-month-old female

We describe a juvenile granulosa cell tumour resulting in pseudopuberty in an infant female. The progression of the clinical signs of puberty were non-consonant and the diagnosis was complicated by marginally elevated serum alpha-fetoprotein levels. The histological appearance of the resected tumour and binding of MIC2 antibody to tumour cells confirmed the diagnosis.

Clinical significance of serum alpha-fetoprotein subfractionation in pediatric diseases

Serum alpha-fetoprotein (AFP) subfraction profile is a predictive indicator for the discrimination of hepatic malignancies, benign liver diseases and yolk sac tumor in adults. In the present study, AFP subfractions were examined in AFP-positive sera from 59 patients of less than 15 years of age. Fractionation of AFP was carried out by lectin affinity crossed-line immunoelectrophoresis. Concanavalin A, Lens culinaris hemagglutinin and phytohemagglutinin E were used as lectins. Fifty-four of 59 (91.5%) AFP subfraction profiles in patients with pediatric diseases were classified into three common types: (1) benign liver disorder, (2) hepatic malignancy and (3) yolk sac tumor. An atypical AFP subfraction profile resembling hepatic malignancy type was found in 5 of 59 (8.5%) infants. It was concluded that estimation of serum AFP subfraction profiles facilitates differential diagnosis of various AFP-positive pediatric diseases, such as hepatoblastoma, hepatoma, hepatic cirrhosis, hepatitis or germ cell tumors.

Construction of age-related reference centiles using absolute residuals

This paper proposes a simple approach to the parametric derivation of age-related reference ranges which avoids the creation of arbitrary age groups, copes easily with a non-linear relation between variability and age, and is computationally simple. After the mean is modelled as a function of age, the age-specific standard deviation is estimated by regressing the absolute residuals on age. The method assumes that the data are, or can be transformed to be, normal at each age, and uses the properties of the half normal distribution. An example is given using 450 measurements of fetal foot length.

Biphasic reduction and concanavalin A binding properties of serum alpha-fetoprotein in preterm and term infants

Reference values for postnatal serum alpha-fetoprotein (AFP) and concanavalin A (ConA) binding subfractions of AFP in preterm and term infants are presented. Preterm infants had 10-fold higher serum concentrations of AFP than did term infants at birth. The reduction of serum values of AFP was biphasic in both groups and differed significantly between the two groups. The first declining phase continued for approximately 4 months in preterm and for 2 months in term infants, and was related to the degree of prematurity. The AFP values reached adult levels by 12 months in preterm and by 9 months in term infants. The developmental pattern of the carbohydrate moiety of AFP was determined by ConA fractioning. The proportion of the ConA nonreactive subfraction of AFP in preterm and term infants at birth was 6% and 13%, respectively; it increased more rapidly in term than in preterm infants but reached 85% to 95% by the age of 6 months in both infant groups. Our results indicate that the postnatal maturation of AFP synthesis is dependent on gestational age. Malignant recurrences of neonatal sacrococcygeal teratomas were associated with an increase in serum concentration of AFP and a decrease in the proportion of the ConA nonreactive subfraction of AFP.

Alpha-fetoprotein: a marker for recurrent apnoea of prematurity?

Plasma alpha-fetoprotein was measured each week for 28 days on 132 preterm babies who were admitted to an intensive care unit. Reference values were established on 53 of these infants who were relatively normal and whose gestations ranged from 29 to 33.9 weeks. Similar studies were done on 79 of the 132 infants with comparable gestational ages who suffered from hyaline membrane disease, transient tachypnoea, recurrent apnoea or growth retardation. Plasma AFP was significantly raised in those with recurrent apnoea but a reason was not established for this observation. The risk of apnoea persisted until AFP levels had reached the reference range. Infants with hyaline membrane disease had lower levels of plasma AFP than the recurrent apnoea group but significantly higher values than controls. Babies who are liable to develop recurrent apnoea can probably be identified at birth as their plasma AFP is exceptionally high. These conclusions refer only to babies who receive a maintenance dose of theophylline from the first week.

Neonatal tumours: Glasgow 1955-86

Fifty one neonatal tumours were diagnosed in Glasgow over a 32 year period. The most common tumours were teratomas (n=19), others being renal tumours (n=9), soft tissue sarcomas (n=8), neuroblastomas (n=7), and others (n=8). Of the total, 31% were malignant. Neonatal tumours pose difficult problems of management, and because of their comparative rarity and the great potential for cure we recommend that all centres dealing with such patients should contribute to and benefit from a Neonatal Tumour Registry.