Serum alpha-fetoprotein in adults, in women during pregnancy, in children at birth, and during the first week of life: a sex difference

Peripheral blood markers of sepsis in foals born from mares with experimentally induced ascending placentitis

BACKGROUND

Neonatal sepsis is a leading cause of neonatal death during the first-week postfoaling. Despite recent advancements in the diagnosis and treatment of sepsis in the newborn foal, the non-specific clinical signs and subtle nature of this disease may result in delayed diagnosis until severe progression of the disease; thus, early detection of sepsis remains critical for a favourable outcome. This study aimed to identify early blood markers as predictive of sepsis on foals.

METHODS

Thirty-five foals were allocated into three groups: healthy control foals (n=7) and foals born from mares with placentitis: septic foals (n=9) and non-septic foals (n=19). Blood samples were obtained immediately after foaling and at 12, 24 and 48 hours. All samples were assessed for glucose, lactate, triglycerides, total cholesterol, urea, creatinine, total solids, fibrinogen, gamma-glutamyl transferase (GGT), serum amyloid A (SAA) and alpha-fetoprotein (AFP) concentrations.

RESULTS

At foaling, glucose and GGT concentrations were lower in septic foals (P<0.001). Of interest, SAA, AFP, creatinine and total cholesterol were higher in septic foals at parturition (P<0.05). At 12 hours, lactate, triglycerides and total cholesterol concentrations were higher in septic foals. When evaluated at 24 and 48 hours, higher concentrations of SAA and AFP were found in placentitis foals than in the control group.

CONCLUSIONS

Total cholesterol and lactate appear to be suitable markers for sepsis during the first 24 hours postpartum. Septic foals displayed altered energy metabolisms as determined by increased triglycerides and cholesterol concentrations, hypoglycaemia at birth and reduced activity of the GGT and increased lactate and urea concentrations. Sepsis was associated with high concentrations of SAA and AFP.

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.

Neonatal Estrogen Causes Irreversible Male Infertility via Specific Suppressive Action on Hypothalamic Kiss1 Neurons

Aberrant exposure to estrogen-like compounds during the critical developmental period may cause improper hypothalamic programming, thus resulting in reproductive dysfunction in adulthood in male mammals. Kisspeptin-neurokinin B-dynorphin A (KNDy) neurons in the arcuate nucleus (ARC) have been suggested to govern tonic GnRH/gonadotropin release to control reproduction in male mammals. In this study, we report that chronic exposure to supraphysiological levels of estrogen during the neonatal period caused an irreversible suppression of KNDy genes in the ARC, resulting in reproductive dysfunction in male rats. Daily estradiol benzoate (EB) administration from days 0 to 10 postpartum caused smaller seminiferous tubules, abnormal spermatogenesis, and a decrease in plasma testosterone in adult male rats. The neonatal EB treatment profoundly suppressed LH pulse and ARC KNDy gene expression at adulthood, but it failed to affect the number of GnRH gene-expressing cells in male rats. The EB treatment failed to affect gene expression of other neuropeptides, such as GHRH, proopiomelanocortin, and agouti-related protein in the ARC, suggesting that ARC KNDy neurons would be a specific target of neonatal estrogen to cause male reproductive dysfunction. Because LH secretory responses to kisspeptin challenge and GnRH expression were spared in male rats with the EB treatment, LH pulse suppression is most probably due to ARC KNDy deficiency. Taken together, the current study indicates that chronic exposure to estrogenic chemicals in the developing brain causes a defect of ARC KNDy neurons, resulting in an inhibition of pulsatile GnRH/LH release and the failure of spermatogenesis and steroidogenesis.

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.

Granulosa cell tumor of the testis in a newborn

Testicular neoplasms are uncommon tumors of childhood. These tumors comprise the germ cell tumors, and other tumors that may originate from histological testicular components, which are unrelated to the germinal lineage. Among the latter are the sex cord-stromal tumors (SCST), an important entity in newborns. SCSTs comprise, among others, granulosa cell tumors, which are more common in the ovary, but in rare cases may develop in the testis. The prognosis is excellent since it is universally benign. Diagnosis, which is sometimes challenging, is usually made after orchiectomy and pathological examination, which is characterized by morphological features and positive expression of inhibin, calretinin, and vimentin, and negative for alpha-fetoprotein. The authors present the case of a newborn with a right enlarged testis detected during the first examination after birth. Ultrasonography showed a heterogeneous solid/cystic mass in the right testis, without retroperitoneal lymphadenopathy. A right inguinal orchiectomy was performed 21 hours after birth. Pathologic examination revealed a juvenile granulosa cell tumor of the right testicle. After 4 years of follow-up, as expected, the child presented an uneventful outcome.

Hepatocellular carcinoma during pregnancy: is hepatocellular carcinoma more aggressive in pregnant patients?

BACKGROUND/PURPOSE

Hepatocellular carcinoma (HCC) during pregnancy is a very rare condition and is believed to have a worse prognosis than HCC in non-pregnant women. We evaluated the prognosis and the diagnostic and therapeutic strategies for HCC in pregnant women.

METHODS

We retrospectively analyzed 4 cases in our hospital and 44 cases described in the medical literature since 1957; we also compared the cases reported before 1995 and those reported during/after 1995.

RESULTS

The overall 6-month and 1-, 2-, and 3-year survival rates in the patients reported in the literature were 50, 29.5, 18.2, and 13.6%, respectively (n = 44). The mean ages at diagnosis before and during/after 1995 were 31.4 ± 7.2 and 28.9 ± 4.4 years, respectively (P = 0.113). The following characteristics were significantly more common in the later group: fewer pregnancies; the absence of advanced signs or symptoms; receipt of therapy; tendency to undergo surgery; and higher 6-month and 1-, 2-, and 3-year survival rates. The median survivals of the groups before and during/after 1995 were 18 and 25.5 months, respectively (P < 0.001).

CONCLUSIONS

The morbidity and mortality of HCC during pregnancy has improved over time, as diagnoses have tended to be made earlier and patients have tended to receive surgical and other treatments.

Levels and correlates of alpha-fetoprotein in normal pregnancies among Caucasian and Chinese women

Alpha-fetoprotein has been suggested to have anti breast cancer properties both in adult life and in utero. We studied correlates of maternal serum alpha-fetoprotein levels in normal singleton pregnancies. This was a prospective study relying on women attending maternal units in major teaching hospitals in Boston, USA and Shanghai, China. Specifically, 212 Caucasian women in Boston, and 196 Asian women in Shanghai provided blood samples at the 16th and 27th gestational week. Maternal serum alpha-fetoprotein levels were measured and correlated with maternal and newborn parameters through multiple regression procedures, controlling for a set of potential confounders, including maternal levels of measured hormones. Alpha-fetoprotein was strongly inversely associated with maternal prepregnancy body mass index (-4.73 ng/l at the 27th week per 1 kg/m of body mass index, with 95% confidence intervals -7.09 to -2.36), whereas it was not related to parity, gender of offspring or birth weight. Duration of gestation was inversely associated with maternal alpha-fetoprotein levels, particularly among Caucasian women (-0.22 weeks per 60 ng/l of alpha-fetoprotein at the 27th week, with 95% confidence intervals -0.39 to -0.05). In normal pregnancies, maternal alpha-fetoprotein is inversely related to prepregnancy body mass index and appears to have a physiologic role on duration of gestation rather than on birth weight.

Reproductive factors and extreme levels of maternal serum alpha-fetoprotein: a population-based study

BACKGROUND

Levels of maternal alpha-fetoprotein (AFP) are increased during multiple gestations and preeclampsia but little is known regarding AFP levels in relation to other reproductive factors. Consequently, the objective of this work was to describe the possible relationship between AFP levels during pregnancy and maternal age at birth, maternal age at first birth, parity, time since previous birth and gender of the offspring.

METHODS

Based on national registries we obtained the reproductive history on a population-based cohort of 44 227 women who had serum AFP levels determined in gestational weeks 14-21 and whose present and previous pregnancies resulted in live-born singletons.

RESULTS

Many previous births and an interval of less than 2 years since last birth were significantly associated with extremely low levels of AFP in the mother. However, age at first birth and age at present pregnancy did not influence the AFP level. Women who gave birth to a girl had AFP levels that were 5%[95% confidence interval (CI) 4-6%] lower than those of women who had a boy. Adjustment for birthweight did not significantly affect the estimate.

CONCLUSIONS

Low serum AFP levels in pregnancy are significantly correlated with high parity and with a short interval between births. The significantly lower levels of AFP in women who gave birth to girls could indicate a possible gender-specific regulatory mechanism.

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.

Ethnic differences in breast cancer risk: a possible role for pregnancy levels of alpha-fetoprotein?

BACKGROUND

Breast cancer incidence rates are up to five times higher in white women in the United States compared with Asian women in China and Japan. A search for factors that modify estrogen's biological effect differentially between ethnic groups may add to the understanding of international variations in breast cancer risk. Recent evidence indicates that alpha-fetoprotein, a glycoprotein produced by the fetal liver, has important antiestrogenic properties. During pregnancy, alpha-fetoprotein reaches peak concentrations in maternal serum during the third trimester.

METHODS

We compared pregnancy levels of alpha-fetoprotein in a population with high risk of breast cancer (Boston, MA) and low risk (Shanghai, China). Blood samples were collected around the 16th week and around the 27th week of gestation among women enrolled from March 1994 to October 1995. The number of specimens available for alpha-fetoprotein analysis was 1,033.

RESULTS

Alpha-fetoprotein levels, adjusted for gestational length, were substantially higher in Shanghai compared with Boston women at both time points. When adjustments were made for prepregnancy weight, parity, offspring's sex and maternal age, alpha-fetoprotein levels remained 13% higher in Shanghai at 16 weeks of pregnancy but not at 27 weeks.

CONCLUSIONS

These findings may explain, at least in part, the difference in breast cancer risk between Chinese and American women. On the population level, alpha-fetoprotein may influence risk by modifying the effect of biologically active estrogens both in the mother and in female offspring.

Increased fetal erythroblasts in women who subsequently develop pre-eclampsia

In pregnancies complicated by pre-eclampsia (PET) and/or intrauterine growth restriction (IUGR) there is an increased number of fetal cells in the maternal circulation. The aim of this study was to investigate whether this increase in fetal cells precedes the onset of these pregnancy complications. Doppler ultrasound studies at 24 weeks gestation have shown that increased impedance to flow in the uterine arteries identifies pregnancies with impaired placental perfusion that subsequently develop PET and/or IUGR. We obtained maternal blood from 18 pregnancies with abnormal Doppler results at 22-24 weeks gestation and from 10 normal controls. Fetal erythroblasts were enriched from maternal blood by triple density gradient centrifugation and magnetic cell sorting with CD71 antibody, and the percentage of these erythroblasts was determined. The median proportion of fetal erythroblasts in the group with abnormal Doppler results was 4.5% (range 1-12%), which was significantly higher than in the control group [median 1% (range 0-3%; P < 0.001)]. Furthermore, within the group with abnormal Doppler the median proportion of fetal erythroblasts was higher in the 10 cases which subsequently developed PET and/or IUGR [median 5.5% (range 3-12%)], than in those with normal pregnancy outcome [median 2% (range 1-5%; P < 0.01)]. These findings suggest that impaired placental perfusion is associated with an increase in feto-maternal cell traffic, which precedes the onset of PET and/or IUGR by several weeks.

Fetal cells in maternal blood of pregnancies with severe fetal growth restriction

The aim of this study was to examine whether, in pregnancies with severe early onset fetal growth restriction, the number of fetal erythroblasts in maternal blood is increased. The percentage of fetal erythroblasts in maternal blood, enriched by triple density gradient centrifugation and anti-CD71 magnetic cell sorting, was determined in 10 singleton pregnancies with severe intrauterine growth restriction in which there was Doppler ultrasound evidence of impaired placental perfusion. The values were compared to those of 10 normal pregnancies at the same gestational range of 22-26 weeks. In the growth restricted pregnancies the median number of fetal erythroblasts per 100 nucleated cells in maternal blood enriched for fetal cells was significantly higher than the median value in the control pregnancies (8.5% compared with 1%; P < 0.001). These data suggest that impaired uteroplacental perfusion and severe fetal growth restriction may be associated with placental damage leading to increased feto-maternal cell traffic. Alternatively the rate of transfer of fetal cells into the maternal circulation is not altered but in growth restriction the proportion of fetal erythroblasts in fetal blood is increased.

Prediction of pregnancy outcome with single versus serial maternal serum alpha-fetoprotein tests

OBJECTIVE

The purpose of our study was to determine whether the trend of three maternal serum alpha-fetoprotein samples was more predictive of pregnancy outcome than the initial sample in the evaluation of patients with unexplained alpha-fetoprotein elevations.

STUDY DESIGN

A total of 432 patients with unexplained elevation of their first two maternal serum alpha-fetoprotein samples had a third sample drawn. Pregnancy outcomes were determined. Patients were grouped for analysis according to the level of the initial sample, the final sample, and the trend of three samples. Statistical analysis was by chi 2 and logistic regression, with p < 0.05 considered significant.

RESULTS

The initial maternal serum alpha-fetoprotein was most predictive of preterm delivery (p < 0.001), size small for gestational age (p < 0.001), and intrauterine fetal death (p = 0.009). Neither the final value nor the trend of three values was as prognostic.

CONCLUSION

The first maternal serum alpha-fetoprotein is the best predictor of pregnancy outcome. Obtaining a second sample to confirm the elevation is appropriate, but additional samples provide minimal information.

Mineral metabolism in the developing turkey embryo--I. The effects of developmental age and shell-less culture on trace element contents of selected tissues

1. Turkey embryos were incubated in ovo or in long-term shell-less culture (ex ovo) for 14, 18, 22 or 26 days. The embryos incubated ex ovo exhibited a progressive decline in the rate of growth and were hypocalcemic and hypoproteinemic compared to their in ovo counterparts from day 18 to day 26 of incubation. 2. The ratio of the concentrations of alpha-fetoprotein and albumin (AFP/A) in serum was determined for both groups of embryos. The AFP/A ratio may be useful as a biochemical index to stage avian embryonic development. Using this index it was concluded that ex ovo embryos exhibited a progressive developmental retardation compared to in ovo embryos. 3. Significant differences were observed in serum trace element concentrations for embryos incubated in ovo vs ex ovo. Most notably, serum copper concentration was significantly lower in ex ovo embryos on days 18 and 22 of incubation and significantly higher on day 26 of incubation compared to serum from embryos incubated in ovo. 4. Livers from embryos incubated ex ovo exhibited significant differences trace element levels compared to those incubated in ovo. By day 26 of incubation the concentration and total amount of zinc and iron were markedly elevated, whereas copper was greatly reduced in the livers of embryos incubated ex ovo compared to the corresponding in ovo levels. 5. Hearts from embryos incubated ex ovo contained less zinc and copper and more iron by day 26 of incubation than those from embryos incubated in ovo.(ABSTRACT TRUNCATED AT 250 WORDS)

alpha-Fetoprotein levels in fullterm and very low birthweight infants

Plasma alpha-fetoprotein (alpha-FP) levels were determined in fullterm and very low birthweight (VLBW) infants in the first week of life and serially in a cohort of VLBW infants for the first 24 weeks after delivery. A rapid decline in alpha-FP levels was observed in both the fullterm and VLBW infants initially. Beyond 2 weeks of age, there was a gradual, linear decline until 6 weeks, followed by a more rapid period of decline from 6 to 16 weeks. The decline in the ensuing weeks demonstrated an asymptotic pattern. The half-life of alpha-FP was 7.5 days in the first week of life in both fullterm and preterm infants, 28.7 days from 2 to 6 weeks of life and 11.9 days from 6 to 16 weeks of life in VLBW infants.

Strain and sex differences in serum alpha-fetoprotein levels in Mus musculus

Normal levels of circulating serum alpha-fetoprotein (AFP) in different inbred strains of mice, as determined by radioimmunoassay, are reported. These strains show different and characteristic values for the mean serum AFP concentration, suggesting genetic control of the serum level of this protein. Furthermore, within each strain a difference in serum levels of the protein is observed between sexes; males have a significantly higher serum AFP concentration.

Alpha-fetoprotein: a review

Alpha fetoprotein (AFP) is the major protein of fetal serum and most resembles albumen, which replaces it shortly after birth. It is produced by fetal liver and passes into the amniotic fluid (AF) via fetal urine. A small amount crosses the membranes into the maternal circulation. Excluding fetal blood contamination, elevated AF/AFP levels indicate fetal demise or one of several abnormalities. Maternal serum (MS) AFP measurement can be used as a screening procedure to identify neural tube defects providing a rigorous protocol is followed. This requires that a laboratory establish its normal range of MS/AFP levels between 15 and 20 weeks gestation, employ a reliable assay with adequate controls, and has recourse to genetic counseling as well as expert sonography, amniocentesis and amniography if necessary. Pregnancy is the only normal situation in which AFP is present after birth. It may be present in high levels in certain malignancies and has been useful in monitoring their recurrence. This article will review the history, biochemistry, and different assays of AFP in AF and blood as well as the indications and limitations for their use.