FSH-stimulated Inhibin B (FSH-iB): A Novel Marker for the Accurate Prediction of Pubertal Outcome in Delayed Puberty

BACKGROUND

Clinicians have long been struggling to find an effective tool to predict onset of puberty.

OBJECTIVE

To explore stimulability of inhibin B after exogenous FSH and its potential role for prediction of onset of puberty.

DESIGN AND PARTICIPANTS

Study subjects were enrolled into "exploratory cohort" (n = 42) and "validation cohort" (n = 19). The exploratory cohort was further divided into group 1 (healthy children with spontaneous puberty [SP], n = 26) and group 2 (patients with hypogonadotropic hypogonadism [HH], n = 16). The validation cohort included children who presented with complaints of delayed puberty.

INTERVENTION AND OUTCOME

Participants were subjected to FSH stimulation test and GnRH analogue stimulation test. Cutoffs derived from the exploratory cohort for basal and FSH stimulated inhibin B (FSH-iB) were applied on the validation cohort. Basal LH, GnRH analogue-stimulated LH, basal inhibin B, and FSH-iB were compared with clinical outcomes on a prospective follow-up for prediction of onset of puberty.

RESULTS

There was statistically significant increment in inhibin B after exogenous FSH in group 1 (SP) in both male (188.8 pg/mL; P = 0.002) and female (1065 pg/mL; P = 0.023) subjects. The increment was not statistically significant in group 2 (HH) in both sexes. FSH-iB at a cutoff of 116.14 pg/mL in males and 116.50 pg/mL in females had 100% sensitivity and specificity for labelling entry into puberty. On application of these cutoffs on the validation cohort, FSH-iB had 100% positive predictive value, negative predictive value, and diagnostic accuracy for prediction of pubertal onset.

CONCLUSION

Inhibin B was stimulable in both male and female subjects. FSH-iB can be considered a novel and promising investigation for prediction of onset of puberty. Future studies are required for further validation.

Klotho and activin A in kidney injury: plasma Klotho is maintained in unilateral obstruction despite no upregulation of Klotho biosynthesis in the contralateral kidney

In a new paradigm of etiology related to chronic kidney disease-mineral and bone disorder (CKD-MBD), kidney injury may cause induction of factors in the injured kidney that are released into the circulation and thereby initiate and maintain renal fibrosis and CKD-MBD. Klotho is believed to ameliorate renal fibrosis and CKD-MBD, while activin A might have detrimental effects. The unilateral ureter obstruction (UUO) model is used here to examine this concept by investigating early changes related to renal fibrosis in the obstructed kidney, untouched contralateral kidney, and vasculature which might be affected by secreted factors from the obstructed kidney, and comparing with unilateral nephrectomized controls (UNX). Obstructed kidneys showed early Klotho gene and protein depletion, whereas plasma Klotho increased in both UUO and UNX rats, indicating an altered metabolism of Klotho. Contralateral kidneys had no compensatory upregulation of Klotho and maintained normal expression of the examined fibrosis-related genes, as did remnant UNX kidneys. UUO caused upregulation of transforming growth factor-β and induction of periostin and activin A in obstructed kidneys without changes in the contralateral kidneys. Plasma activin A doubled in UUO rats after 10 days while no changes were seen in UNX rats, suggesting secretion of activin A from the obstructed kidney with potentially systemic effects on CKD-MBD. As such, increased aortic sclerostin was observed in UUO rats compared with UNX and normal controls. The present results are in line with the new paradigm and show very early vascular effects of unilateral kidney fibrosis, supporting the existence of a new kidney-vasculature axis.

The Association Between Serum Activin A Levels and Hypertension in the Elderly: A Cross-Sectional Analysis From I-Lan Longitudinal Aging Study

BACKGROUND

Hypertension is an important risk factor for cardiovascular disease. Activin A, a member of the transforming growth factor-β cytokine family, has been shown to regulate blood pressure through the renin-angiotensin system. However, the relationship between activin A and blood pressure remains uncertain. The objective of this study was to determine whether serum activin A levels are associated with blood pressure.

METHOD

A total of 470 participants of I-Lan longitudinal Aging Study (ILAS) were eligible for this study. Serum levels of activin A were assessed by enzyme-linked immunosorbent assay. Cross-sectional analyses were performed, including comparisons of demographic characteristics, hypertensive status, and activin A levels.

RESULTS

Among the study participants (50% men, mean age, 69 years), 236 (50.2%) were hypertensive and 234 (49.8%) were normotensive. Hypertensive patients had significantly higher serum activin A levels than normotensives (normotensive vs. hypertensive: 507 ± 169 vs. 554 ± 176 pg/ml, mean ± SD, P < 0.001). All subjects were divided into 3 tertiles on the basis of serum activin A levels. Increasing tertiles of activin A were associated with higher systolic blood pressure (SBP), diastolic blood pressure and pulse pressure (PP) (all P < 0.001). After adjusting for all the potential confounding factors, serum activin A concentration was still significantly associated with SBP (P = 0.02) and PP (P = 0.03).

CONCLUSIONS

Serum activin A level was associated with SBP and PP. Further studies are required to assess their causal relationship and the clinical relevance.

Circulating anti-Müllerian hormone (AMH) associates with the maturity of boys' drawings: Does AMH slow cognitive development in males?

PURPOSE

High levels of circulating anti-Müllerian hormone are unique to developing males, but the function of anti-Müllerian hormone in boys is unknown. In mice, anti-Müllerian hormone contributes to the male biases in the brain, but its receptors are present throughout non-sexually dimorphic portions of the brain. In humans, the speed of maturation is the most overt difference between girls and boys. We postulate that this is because anti-Müllerian hormone slows the maturation of the male human brain.

METHODS

One hundred and fourty three 5-year or 6-year-old boys and 38 age-matched girls drew a person and donated a blood sample. The children's drawings were blind-scored to generate a maturity index. The level of anti-Müllerian hormone and the other Sertoli cell hormone, inhibin B, were measured by ELISA. The relationship between the children's age, hormones and maturity index were examined by linear regression analysis.

RESULTS

The girls drew more complex and realistic person than the boys (32%, p = 0.001), with their drawings also being larger (39%, p = 0.037) and more coloured-in (235%, p = 0.0005). The maturity index in boys correlated with age (+r = 0.43, p < 0.0005) and anti-Müllerian hormone level (-r = -0.29, p < 0.0005). The association between maturity index and anti-Müllerian hormone level persisted when corrected for age and for inhibin B (r = -0.24, p = 0.0005). The calculated effect of the median level of anti-Müllerian hormone (1 nM) was equal to 0.81 months of development. The size and colouring of the drawings did not correlate with the boys' age, anti-Müllerian hormone or inhibin B.

CONCLUSIONS

This exploratory study provides the first indicative evidence that circulating anti-Müllerian hormone may influence the development of the human brain.

[Testicular artery-sparing microscopic varicocelectomy combined with Qilin Pills for bilateral varicocele-induced oligoasthenospermia]

OBJECTIVE

To explore the clinical effect of testicular artery-sparing microscopic varicocelectomy (MV) in combination with Qilin Pills (QL) in the treatment of bilateral varicocele-induced oligoasthenospermia.

METHODS

Sixty patients with bilateral varicocele-induced oligoasthenospermia were randomly assigned to receive MV (n=30) or MV+QL (n=30), those in the latter group treated with oral QL for 12 weeks postoperatively. At 4, 8, and 12 weeks after operation, we compared the semen volume, sperm concentration, sperm motility, the levels of serum Inh B, luteinizing hormone (LH) and total testosterone (TT), and the testosterone secretion index (TSI) between the two groups.

RESULTS

After surgery, all the patients showed disappearance of varicocele symptoms, remarkably improved semen volume, sperm concentration, sperm motility, serum Inh B and TT levels, TSI, decreased LH and FSH (P<0.01). At 12 weeks after treatment, statistically significant differences were found between the MV and MV+QL groups in Inh B (138.96±22.26 vs 129.54±22.23) ng/L, LH (3.17±0.12 vs 3.59±0.11) IU/L, TT (13.98±3.02 vs 12.68±3.12) nmol/L, and TSI (4.41±0.53 vs 3.53±0.51) nmol/ IU (P<0.05). The pregnancy rate was significantly higher in the MV+QL than in the MV group (73.4% vs 36.6%, P<0.05).

CONCLUSIONS

Testicular artery-sparing microscopic varicocelectomy combined with Qilin Pills is an effective strategy for the treatment of bilateral varicocele-induced oligoasthenospermia by significantly improving the semen quality of the patient.

Change in the Gastro-Intestinal Tract by Overexpressed Activin Beta A

Originally, activins were identified as stimulators of FSH release in reproduction. Other activities, including secondary axis formation in development, have since been revealed. Here, we investigated the influence of activin βA on the body, including the gastro-intestinal (GI) tract. Initially, the activin βA protein was detected in the serum proportional to the amount of pCMV-rAct plasmid injected. The induced level of activin βA in muscle was higher in female than male mice. Subsequent results revealed that stomach and intestine were severely damaged in pCMV-rAct-injected mice. At the cellular level, loss of parietal cells was observed, resulting in increased pH within the stomach. This phenomenon was more severe in male than female mice. Consistent with damage of the stomach and intestine, activin βA often led to necrosis in the tip of the tail or foot, and loss of body weight was observed in pCMV-rAct-injected male but not female mice. Finally, in pCMV-rAct-injected mice, circulating activin βA led to death at supraphysiological doses, and this was dependent on the strain of mice used. Taken together, these results indicate that activin βA has an important role outside of reproduction and development, specifically in digestion. These data also indicate that activin βA must be controlled within a narrow range because of latent lethal activity. In addition, our approach can be used effectively for functional analysis of secreted proteins.

Anti-Müllerian Hormone Is a Marker for Chemotherapy-Induced Testicular Toxicity

Due to increased numbers of young cancer patients and improved survival, the impact of anticancer treatments on fertility has become a major health concern. Despite mounting research on ovarian toxicity, there is paucity of data regarding reliable biomarkers of testicular toxicity. Our aim was to evaluate anti-Müllerian hormone (AMH) as a marker for chemotherapy-induced testicular toxicity. Serum AMH and a panel of gonadal hormones were measured in male cancer patients at baseline and after chemotherapy. In the preclinical setting, mice were injected with diverse chemotherapies and were killed 1 week or 1, 3, or 6 months later. We evaluated spermatogenesis by AMH as well as qualitative and quantitative sperm parameters. Nineteen patients were enrolled, the median age was 38 years (21-44 y). Serum AMH was correlated with increased FSH and T and decreased inhibin-B in gonadotoxic protocols (cisplatin or busulfan) and remained unchanged in nongonadotoxic protocols (capecitabine). AMH expression had the same pattern in mice serum and testes; it was negatively correlated with testicular/epididymal weight and sperm motility. The increase in testicular AMH expression was also correlated with elevated apoptosis (terminal transferase-mediated deoxyuridine 5-triphosphate nick-end labeling) and reduced proliferation (Ki67, proliferating cell nuclear antigen; all seminiferous tubules cells were analyzed). Severely damaged mice testes demonstrated a marked costaining of AMH and GATA-4, a Sertoli cell marker; staining that resembled the pattern of the Sertoli cell-only condition. Our study indicates that the pattern of serum AMH expression, in combination with other hormones, can delineate testicular damage, as determined in both experimental settings. Future large-scale clinical studies are warranted to further define the role of AMH as a biomarker for testicular toxicity.

Association between GH receptor polymorphism (exon 3 deletion), serum IGF1, semen quality, and reproductive hormone levels in 838 healthy young men

INTRODUCTION

GH activity may be involved in male reproductive function. A common genetic polymorphism in the gene encoding the GH receptor (GHR) results in deletion of the entire exon 3 sequence (GHRd3 isoform). The short GHRd3/d3 isoform seems more sensitive compared with full-length receptors (GHRfl/fl).

AIM

TO INVESTIGATE THE ASSOCIATIONS BETWEEN GH ACTIVITY, EVALUATED BY EXON 3 GHR POLYMORPHISM, AND SERUM IGF1 VS REPRODUCTIVE HORMONES, SEMEN QUALITY, AND PRE- AND POSTNATAL GROWTH IN HEALTHY YOUNG MALES (N=838, MEAN AGE: 19.4 years).

RESULTS

Compared with GHRfl/fl homozygous individuals (n=467) GHRd3/d3 homozygous individuals (n=69) tended to have larger semen volume (3.2 (2.4-4.3) vs 3.6 (2.6-4.7) ml, P=0.053) and higher serum inhibin-B levels (208 pg/ml (158-257) vs 227 pg/ml (185-264), P=0.050). Semen quality, levels of gonadotropins, testosterone, estradiol, sex hormone-binding globulin, and IGF1 were not associated with GHRd3 genotype. A twofold increase in serum IGF1 was associated with a 13% (4-23) increase in calculated free testosterone (P=0.004). By contrast IGF1 was inversely associated with serum inhibin-B (P=0.027), but showed no associations to semen quality. GHR genotype and serum IGF1 were not associated with size at birth or final height.

CONCLUSIONS

GHRd3 polymorphism seemed only to have a weak influence on male reproductive function of borderline significance. The sensitive GHRd3/d3 genotype may slightly increase testicular function, as evaluated by semen volume and levels of inhibin-B, but does not seem to influence Leydig cell steroidogenesis. GHR genotype did not influence pre- and postnatal growth.

[Study on the association between maternal urinary phthalate metabolites and testicular steroid hormones in the cord blood in a Chinese population]

OBJECTIVE

The purposes of our study were to investigate the association between maternal urinary phthalate metabolites and the levels of inhibin B (INHB) and insulin-like factor 3 (INSL3) in the cord blood in a Chinese pregnant population.

METHODS

Maternal urine samples in the third trimester of pregnancy of 69 participants were collected and stored, and the samples of cord blood (10 ml) were collected at delivery between June 2011 and September 2012 in a comprehensive hospital of gynecology and obstetrics in Tianjin, China.Four phthalate metabolites, monomethyl phthalate (MMP), monoethyl phthalate (MEP), monobutyl phthalate (MBP), and mono-2-ethylhexyl phthalate (MEHP) were measured in the urine samples using liquid chromatography-tandem mass spectrometry. The levels of INHB, INSL3 in the cord blood were tested by ELISA. Associations of phthalate exposure with INHB and INSL3 levels were determined by spearman correlation and multiple regression model analysis.

RESULTS

The median concentrations of observed metabolites in descending order were 49.74 µg/L for MMP, 24.96 µg/L for MEHP, 19.52 µg/L for MEP and 17.73 µg/L for MBP. The median concentrations of INHB and INSL3 were 89.09 and 106.21 ng/L.Significant negative associations between INHB and MMP(β' = -0.252), MEP(β' = -0.363) or the sum value (∑PAEs) (β' = -0.346) were found by the multiple regression model analysis. For INSL3, only the sum value (β' = -0.313) was inversely significantly associated with the levels of INSL3 in the cord blood.

CONCLUSIONS

Maternal urinary phthalate metabolites were associated with INHB and INSL3 in the cord blood in a Chinese population.

Inhibin B levels in hypothyroid males

BACKGROUND

The primary role of inhibin B is the regulation of gametogenesis via negative feedback on the production of follicle stimulating hormone (FSH) by the pituitary.

METHODS

We studied 14 males with primary hypothyroidism due to various etiologies to determine if they exhibited hypogonadotrophic hypogonadism involving the reproductive segment of the gonadotrophic axis. Levels of inhibin B, FSH, luteinizing hormone, testosterone, free thyroxine, and thyrotropin were measured.

RESULTS

The mean level of inhibin B in males with primary hypothyroidism was found to be approximately half that of normal males. The FSH level remained within the normal range and no reciprocal increase was observed as occurs in other conditions with reduced inhibin B.

CONCLUSIONS

Our results indicate that primary hypothyroidism has a significant effect on inhibin B levels without reciprocal increase in FSH, which is consistent with a hypogonadotrophic hypogonadal state affecting the reproductive segment of the gonadotrophic axis.

Anti-Müllerian hormone and antral follicle count reveal a late impairment of ovarian reserve in patients undergoing low-gonadotoxic regimens for hematological malignancies

The impact of cancer therapy on the reproductive potential of patients is increasingly recognized because survival rates of patients have clearly improved in recent years. Different fertility preservation methods, either generally accepted or still experimental, are currently available, and counseling of patients requires a delicate balance between the efficacy and side effects of the proposed method and the characteristics of both the tumor and the therapy. Deeper knowledge of the effects of cancer therapy on the reproductive potential of patients over time is required to identify the most appropriate fertility preservation method. In this paper, we report a case-control study in which female patients who were diagnosed with hematological malignancies and treated with chemotherapy and/or radiotherapy were compared with age-matched controls in terms of ovarian reserve, as measured by ultrasound examination and hormonal status. By stratifying patients for gonadotoxicity of the therapy received and time elapsed from the end of the therapy, we report that patients treated with low gonadotoxic therapies, while being similar to age-matched controls in their ovarian reserve when evaluated within a few years from the end of the therapy, show a clear impairment over longer times. We also report that anti-Müllerian hormone is the most sensitive hormonal parameter in detecting changes in ovarian reserve when compared with follicle-stimulating hormone or inhibin-B. This study stresses the importance of accurate counseling at the time of diagnosis of cancer and emphasizes the risks of infertility with low gonadotoxic therapies that may reduce the reproductive window of survivors.

First-trimester maternal serum activin A in pre-eclampsia and fetal growth restriction

OBJECTIVE

To investigate whether the reported increase in maternal serum activin A concentration in pre-eclampsia is evident from the first trimester.

DESIGN

This was a case-control study carried out in antenatal clinics among singleton pregnancies at 10-14 weeks of gestation.

METHODS

Activin A concentration was measured in stored maternal serum samples obtained at 11-14 weeks of gestation from 131 women who subsequently developed pre-eclampsia, 77 who developed non-proteinuric pregnancy-induced hypertension, 141 with fetal growth restriction in the absence of hypertensive complications and from 494 normotensive controls.

RESULTS

Compared to the median activin A level in the control group (1.00 MoM), the median MoM in the patients who subsequently developed pre-eclampsia and pregnancy-induced hypertension (1.49 MoM and 1.32 MoM, respectively) was significantly increased (p < 0.001), and in patients with fetal growth restriction (1.02 MoM) it was not significantly different (p = 0.57). In the pre-eclampsia group (n = 131) the disease was considered to be sufficiently severe to necessitate iatrogenic delivery before 35 weeks in 25 patients, and in this group the median MoM was 1.92.

CONCLUSION

Maternal serum activin A concentration at 12 weeks of gestation in pregnancies which subsequently develop hypertensive disease is increased, whereas in those complicated by fetal growth restriction it is normal.

Phenotyping and genetic studies of 357 consecutive patients presenting with premature ovarian failure

OBJECTIVE

Premature ovarian failure (POF) encompasses a heterogeneous spectrum of conditions, with phenotypic variability among patients. The etiology of POF remains unknown in most cases. We performed a global phenotyping of POF women with the aim of better orienting attempts at an etiological diagnosis.

DESIGN AND METHODS

We performed a mixed retrospective and prospective study of clinical, biological, histological, morphological, and genetic data relating to 357 consecutive POF patients between 1997 and 2008. The study was conducted at a reproductive endocrinology referral center.

RESULTS

Seventy-six percent of the patients presented with normal puberty and secondary amenorrhea. Family history was present in 14% of the patients, clinical and/or biological autoimmunity in 14.3%. Fifty-six women had a fluctuating form of POF. The presence of follicles was suggested at ultrasonography in 50% of the patients, and observed in 29% at histology; the negative predictive value of the presence of follicles at ultrasonography was 77%. Bone mineral density alterations were found in 58% of the women. Eight patients had X chromosomal abnormalities other than Turner's syndrome, eight other patients evidenced FMR1 pre-mutation. Two other patients had autoimmune polyendocrine syndrome type 2 and 1.

CONCLUSION

A genetic cause of POF was identified in 25 patients, i.e. 7% of the whole cohort. POF etiology remains most often undiscovered. Novel strategies of POF phenotyping are in such content mandatory to improve the rate of POF patients for whom etiology is identified.

Neonatal estrogenic effects upon the male rat pituitary: early gonadotrophin attenuation precedes long-term recovery

Neonatal exposure to potent estrogenic compounds can affect multiple components of the male reproductive system causing impaired development of the epithelium and overgrowth of stromal tissue in the epididymis, vas deferens, seminal vesicles, and prostate. However, very little is known about the direct effects of estrogenic compounds on the anterior pituitary gland. In this study we have investigated the effects of neonatal estrogenic exposure upon the anterior pituitary. Both the early- and late-stage effects of exposure to a synthetic estrogenic agent, diethylstilbestrol (DES), upon pituitary gonadotroph cell function were assessed. We administered either a high dose (10 microg) or a low dose (0.1 microg) of DES to male rats during their neonatal period (P2-12). Gonadotroph function, cell number and morphology shortly after DES treatment (P18) and during adulthood (P90) were assessed. At P18 there was a significant decrease in follicle stimulating hormone (FSH) immunoreactivity in the pituitary gonadotroph cells in the high DES dose treated rats compared to control animals. No significant change in luteinizing hormone (LH) was observed at either DES dose. In adulthood (P90), there was no significant difference in FSH or LH gonadotroph immunoreactivity between control rats and any dose of DES-treated rats. Therefore, despite acute and selective ablation of FSH expression the gonadotrophs were able to recover in adulthood, suggesting that perinatal estrogenic exposure was only temporarily deleterious.

Maternal serum inhibin-A and activin-A levels in the first trimester of pregnancies developing pre-eclampsia

OBJECTIVE

To evaluate whether measurement of maternal serum inhibin-A and activin-A at 11 + 0 to 13 + 6 weeks of gestation, alone or in combination with second-trimester uterine artery pulsatility measured by Doppler velocimetry, is useful in predicting those women who will develop pre-eclampsia.

METHODS

This was a nested case-control study of pre-eclampsia cases with controls matched for gestational age and storage time for the maternal serum. Samples were collected as part of a first-trimester prenatal chromosomal anomaly screening program. Activin-A and inhibin-A were measured using a commercial enzyme-linked immunosorbent assay and the clinical outcomes were blinded to the operator. All the patients underwent uterine artery Doppler flow velocimetry to measure the mean pulsatility index at 22-24 weeks' gestation.

RESULTS

In total there were 64 cases with pre-eclampsia, with 34 delivering prior to 35 weeks of gestation. The control group included 240 cases. In the control group the levels of activin-A and inhibin-A did not change across the narrow gestational window and the median levels were 2.16 ng/mL and 231.13 pg/mL, respectively. In the pre-eclamptic group levels of activin-A and inhibin-A were significantly increased, at 2.52 ng/mL and 286.64 pg/mL (1.24 multiples of the median (MoM) and 1.17 MoM, respectively). There was no difference in the median MoM in those delivering prior to 35 weeks and those delivering later. At cut-offs of the 90(th) centile of normal, activin-A and inhibin-A levels would have identified 20% and 35%, respectively, of cases that would develop pre-eclampsia. When combined with uterine artery Doppler, activin-A measurement could have increased the detection rate from 55% to 63% and inhibin-A measurement could have increased it to 68% at a 5% false positive rate.

CONCLUSION

Although increased in the first trimester, levels of activin-A and inhibin-A are probably too low to make a significant contribution to screening for pre-eclampsia at this time.

Endometrial inhibin/activin beta-B subunit expression is related to decidualization and is reduced in tubal ectopic pregnancy

CONTEXT

Ectopic pregnancy is common but remains difficult to diagnose accurately. There is no serum test to differentiate ectopic from intrauterine gestation.

OBJECTIVE

Our objective was to investigate differential gene expression in decidualized endometrium of ectopic pregnancy.

DESIGN

Tissue and serum analysis informed by microarray study was performed.

SETTING

The study was performed at a large United Kingdom teaching hospital.

PATIENTS OR OTHER PARTICIPANTS

Women undergoing surgical termination of pregnancy (n = 8), evacuation of uterus for miscarriage (n = 6), and surgery for tubal ectopic pregnancy (n = 11) were included in the study. Endometrium was collected from normally cycling women undergoing hysterectomy.

INTERVENTIONS

Decidualized endometrium was subjected to microarray analysis, morphological assessment, and immunohistochemistry. Endometrial stromal fibroblasts were cultured in the presence of decidualizing stimuli.

MAIN OUTCOME MEASURES

Differential expression of potentially secreted molecules was calculated.

RESULTS

Inhibin/activin beta-B expression was lower in decidualized endometrium from ectopic pregnancies when compared with that of ongoing pregnancies (P < 0.01) or miscarriages (P < 0.01). The localization of the beta-B subunit was more marked in decidualized than nondecidualized stroma. Decidualization of stromal fibroblasts in vitro was associated with increased beta-B expression (P < 0.05). Endometrial stroma of ectopic pregnancies was less decidualized morphologically (P < 0.05), with lower prolactin (P < 0.01) and IGF binding protein-1 (P < 0.005) expression. Serum activin B was lower in ectopic pregnancies (P < 0.005) than in intrauterine pregnancies, whereas there was no difference in progesterone concentrations.

CONCLUSIONS

Despite similar concentrations of progesterone, the endometrium of ectopic pregnancies is less decidualized than intrauterine pregnancies. Expression of the beta-B subunit is related to decidualization and can be detected in the circulation as activin B. Serum activin B concentrations are lower in ectopic pregnancy.

Effects of peripheral nerve ischemia-reperfusion model on serum cytokine levels

AIM

Although the neuropathology of ischemic nerve fiber degeneration is relatively well known, its pathogenesis is poorly understood. Local cytokines, which have neuroprotective effects on inflammation and repair, participate in the process by undefined mechanisms. In this study, we evaluated the effects of ischemia and reperfusion on the sciatic nerve of the rat and investigated the probable effects of cytokines on this period.

MATERIAL AND METHODS

In the current study, ischemia and reperfusion injury of sciatic nerve was rendered by clamping the femoral artery and vein of the rat for three hours and was followed by varying durations of reperfusion. Activin A, TGF Beta1 and TGF, Beta2 levels were measured in serum samples.

RESULTS

TGF Beta1 and Activin A were found to be increased in the ischemic groups compared with the control group (p < 0.05). A significant difference was found between the experimental groups after reperfusion (p < 0.05). There was no statistical significance for TGF Beta2 levels between the study groups (p > 0.05).

CONCLUSION

Ischemia causes some important changes in biochemical parameters, and nerve injury continues for a while according to the reperfusion time. Ischemia-reperfusion injury of peripheral nerves caused by various reasons therefore affects the levels of cytokines.

Serum inhibin-B and follicle stimulating hormone as predictors of the presence of sperm in testicular fine needle aspirate in men with azoospermia

OBJECTIVE

Inhibin-B (Inh-B) is produced by Sertoli cells and controls Follicle Stimulating Hormone (FSH) secretion through a negative feedback mechanism. The primary aim of this study was to compare Iotanh-B with FSH as predictors of the recovery of sperm in testicular fine needle aspirate in men with azoospermia.

DESIGN

In 51 men with azoospermia basal values of Luteinizing Hormone (LH), FSH, prolactin and testosterone as well as Inh-B values before and 24 h and 48 h after the administration of 300 IU recombinant human FSH were determined. Testicular Fine Needle Aspiration (FNA) was also carried out. Thirty-one young healthy men were also enrolled in the study as controls.

RESULTS

There was significant difference between men with azoospermia and controls with regard to the basal Inh-B levels [median (interquartile range) 37.2 (36) vs. 103.0 (90) pg/mL, respectively, p=0.003] but not to the stimulated Inh-B levels [40.5 (41) vs. 73.0 (44) pg/mL, p=0.113 at 24 h and 34.3 (34) vs. 82.0 (50) pg/mL, p=0.098 at 48 h)]. The Area Under Curve in Receiver Operating Characteristic curves were similar for Inh-B and FSH (0.610 vs. 0.716, respectively, p=0.151) as far as prediction of sperm retrieval is concerned.

CONCLUSIONS

Basal serum Inh-B values are significantly lower in men with azoospermia compared to controls. However, Inh-B is not superior to FSH in predicting the presence of sperm in testicular fine needle aspirate.

The Timing of Neonatal Brain Damage

Although neonatal morbidity and mortality are less than in the past, the risk of pre-natal and neonatal brain damage has not been eliminated. In order to optimize pre-natal, perinatal and neonatal care, it is necessary to detect factors responsible for brain damage and obtain information about their timing. Knowledge of the timing of asphyxia, infections and circulatory abnormalities would enable obstetricians and neonatologists to improve prevention in pre-term and full-term neonates. Cardiotocography has been criticized as being too indirect a sign of fetal condition and as having various technical pitfalls, though its reliability seems to be improved by association with pulse oximetry, fetal blood pH and electrocardiography. Neuroimaging is particularly useful to determine the timing of hypoxic-ischemic brain damage. Cranial ultrasound has been used to determine the type and evolution of brain damage. Magnetic resonance has also been used to detect antenatal, perinatal and neonatal abnormalities and timing on the basis of standardized assessment of brain maturation. Advances in the interpretation of neonatal electroencephalograms have also made this technique useful for determining the timing of brain lesions. Nucleated red blood cell count in cord blood has been recognized as an important indication of the timing of pre-natal hypoxia, and even abnormal lymphocyte and thrombocyte counts may be used to establish pre-natal asphyxia. Cord blood pH and base excess are well-known markers of fetal hypoxia, but are best combined with heart rate and blood pressure. Other markers of fetal and neonatal hypoxia useful for determining the timing of brain damage are assays of lactate and markers of oxidative stress in cord blood and neonatal blood. Cytokines in blood and amniotic fluid may indicate chorioamnionitis or post-natal infections. The determination of activin and protein S100 has also been proposed. Obstetricians and neonatologists can therefore now rely on various methods for monitoring the risk of brain damage in the antenatal and post-natal periods.

Increased Plasma Concentrations of Activin A Predict Intraventricular Hemorrhage in Preterm Newborns

Background: Intraventricular hemorrhage (IVH) is a major cause of neurologic disabilities in preterm newborns. We evaluated the use of plasma activin A concentrations to predict the development of perinatal IVH.

Methods: We measured nucleated erythrocyte (NRBC) counts, plasma activin A, hypoxanthine (Hyp), and xanthine (Xan) in arterial blood samples obtained from 53 preterm infants during the first hour after birth. Cerebral ultrasound was performed within 48 h of birth and repeated at 5- or 6-day intervals until the age of 4 weeks.

Results: Grade I or II IVH was detected during the first 10 days of life in 11 of 53 patients (21%). Activin A, Hyp, and Xan concentrations and NRBC counts were higher in preterm newborns who subsequently developed IVH than in those who did not (P &lt;0.0001, except P = 0.019 for Xan). Neonatal activin A was correlated (P &lt;0.0001) with Hyp (r = 0.95), Xan (r = 0.90), and NRBC count (r = 0.90) in newborns without later IVH and in those who developed IVH (Hyp, r = 0.89, P = 0.0002; Xan, r = 0.95, P &lt;0.0001; NRBC count, r = 0.90, P = 0.0002). At a cutoff of 0.8 μg/L activin A, the sensitivity and specificity were 100% [11 of 11; 95% confidence interval (CI), 71%–100%] and 93% (39 of 42; 95% CI, 81%–98%), and positive and negative predictive values were 79% (95% CI, 61%–100%) and 0% (95% CI, 0%–2%), respectively. The area under the ROC curve was 0.98.

Conclusions: Activin A concentrations at birth are increased in preterm newborns who later develop IVH and may be useful for early identification of infants with hypoxic-ischemic brain insults who are at high risk for IVH.

Possible contribution of serum activin A and IGF-1 in the development of hepatocellular carcinoma in Egyptian patients suffering from combined hepatitis C virus infection and hepatic schistosomiasis

OBJECTIVES

The present study evaluated the role of activin A, insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 (IGFBP-3) in Egyptian patients suffering from combined hepatitis C virus (HCV) infection and hepatic schistosomiasis.

DESIGN AND METHODS

Four groups were included in the present study. Group I: 30 healthy subjects were included as controls; Group II (HCV): 30 patients with chronic liver disease due to HCV infection without evidence of schistosomiasis; Group III (SHF + HCV): 30 patients with combined disease, chronic schistosomal hepatic fibrosis (SHF) and chronic hepatitis C infection; Group IV (HCC): 30 patients with hepatocellular carcinoma associated with chronic hepatitis C virus and schistosomal infection.

RESULTS

Patients with HCV, HCV + SHF and those with HCC had a significantly higher serum activin A compared with the control group (P < 0.001). Serum activin A level (mean +/- SD) was 5.7 +/- 2.76, 10.59 +/- 3.59, 15.39 +/- 4.61 and 19.93 +/- 5.43 ng/mL in controls, HCV patients, HCV + SHF patients and HCC patients, respectively. Serum IGF-1 was significantly lower in HCV patients, HCV + SHF patients and HCC patients compared to the control group (P < 0.001). Serum IGF-1 was 121.7 +/- 73.4, 76.7 +/- 23.5, 35.7 +/- 17.6 and 39.9 +/- 25.9 ng/mL in controls, HCV patients, HCV + SHF patients and HCC patients, respectively. Similarly, serum IGFBP-3 was significantly lower in HCV patients, HCV + SHF patients and HCC patients compared to the control group (P < 0.001). Furthermore, serum insulin-like growth factor binding protein 3 (IGFBP-3) was significantly lower in patients with HCC compared to patients with HCV or those with HCV + SHF (P < 0.01 and P = 0.024, respectively). The median (range) of serum IGFBP-3 was 4452 (352.2-8965), 3457 (1114-6000), 2114 (867-5901) and 1202 (576-3994) ng/mL in controls, HCV patients, HCV + SHF patients and HCC patients, respectively. Serum activin A correlated positively with Child-Pugh scoring in patients with HCV, HCV + SHF and those with HCC. The correlation coefficient was significant, at 0.001, in total cases.

CONCLUSIONS

We conclude that patients with HCV, HCV + SHF and those with HCC have a significantly higher serum activin A when compared with controls. Serum activin A level was significantly higher in patients with HCV + SHF compared to those with HCV alone (P < 0.01) with a significant positive correlation between the serum activin A level and Child-Pugh scoring in patients with HCV, HCV + SHF and those with HCC. Furthermore, serum IGF-1 and IGFBP-3 levels were significantly reduced in patients with HCV, HCV + SHF and those with HCC compared to the control group. We suggest that this pattern (high activin A and low IGF-1 and its binding protein 3) may play a role in development of HCC in Egyptian patients suffering from combined hepatitis C virus infection and hepatic schistosomiasis.

Umbilical Cord Serum Activin A Levels are Increased in Pre-eclampsia with Impaired Blood Flow in the Uteroplacental and Fetal Circulation

The aims of the present study were to evaluate the umbilical cord serum activin A concentrations in complicated pregnancies and also to explore the relationship between activin A levels and blood flow velocity in fetal arteries. Umbilical cord blood samples were obtained postpartum after a full term uneventful gestation (control group, n=40), and from pregnancies complicated by gestational diabetes (n=13), preterm labour (n=18), or pre-eclampsia (n=19). Cord serum activin A levels were three-fold higher in pregnancies complicated by pre-eclampsia (1.17+/-0.14 ng/ml, p<0.01) than in the control group (0.43+/-0.03 ng/ml), but were unaltered in the diabetes and preterm labour groups. The pre-eclampsia group had a marked increase of umbilical artery pulsatility index (PI) and also a decrease of middle cerebral artery PI (p<0.01). Furthermore, activin A concentration correlated directly with the umbilical artery PI (r=0.540, p=0.021), with the length of stay in the Neonatal Intensive Care Unit (r=0.857, p<0.001) and also with cord blood pH (r=-0.886, p<0.001). In conclusion, umbilical cord serum activin A levels are increased in the presence of pre-eclampsia and provide an indirect marker of impaired blood flow in the uteroplacental and fetal circulation.

Uterine vein and maternal urinary levels of activin A and inhibin A in pre-eclampsia patients

OBJECTIVES

The aims of this study were to investigate if (i) urinary concentrations of activin A and inhibin A are altered in pre-eclampsia (PE) and (ii) to study the relationship between uterine vein and peripheral vein concentrations of these hormones in PE patients.

DESIGN AND METHOD

In a retrospective study, maternal peripheral vein and uterine vein serum and maternal urine samples collected at the time of delivery were analysed. There were three groups of patients; (i) group 1: term normal pregnancies (n = 19) (ii) group 2: patients who developed PE < or = 37 weeks (n = 17) and (iii) group 3: patients who developed PE 37-40 weeks (n = 8). Serum and urinary activin A, follistatin, inhibin A and pro alpha C and urinary creatinine levels were measured using enzyme immunoassays in the laboratory.

RESULTS

Normal pregnant urine samples had very low levels of activin A and inhibin A. Both groups 2 and 3 PE patients had significantly higher levels of inhibin A (P < 0.001) and activin A (P < 0.001) compared to the controls. Pro-alpha C was not altered and follistatin was below the detection limit of the assay in the urine. Maternal peripheral serum activin A and inhibin A were significantly higher in groups 2 (P < 0.001) and 3 (P < 0.05) patients compared to the controls. Pro-alpha C-containing inhibins were higher in group 2 patients (P < 0.05) compared to the controls in the peripheral circulation. Uterine vein serum activin A and inhibin A levels were also significantly higher in groups 2 (P < 0.001) and 3 (P < 0.05) patients compared to the controls. There was a highly significant positive correlation between peripheral and uterine vein serum concentrations of activin A, follistatin, inhibin A and pro alpha C, suggesting the same source for these proteins in PE.

CONCLUSION

Urinary activin A and inhibin A are raised in groups 2 and 3 PE patients. The magnitude of rise (> 25-fold) suggests these proteins may rise in patients before the onset of the clinical symptoms of PE. Uterine vein levels of these proteins are also raised in PE.

Activin A, hypoxia and the prediction of obstetric outcomes

On the back of sheep experiments showing that uterine hypoxia induces a rapid and sustained elevation of fetal activin A levels, we undertook two prospective studies to explore whether this novel observation could be exploited clinically. The first was a prospective labour ward study investigating whether umbilical arterial activin A levels at delivery correlated with either neonatal hypoxic ischaemic encephalopathy or pH. Unfortunately, we were unable to demonstrate a link with either, but found that levels were significantly depressed among those who had an emergency Caesarean section, suggesting a possible role in active labour. Second, we investigated the link between activin A and intrauterine growth restriction (IUGR), a condition of fetoplacental hypoxia, by measuring levels in women presenting for antenatal ultrasound biometry with clinical suspicion of a small baby. We found that, compared to pregnancies with a baby that was small for gestational age (SGA) but otherwise healthy, levels were 2.4 and 8 times higher, respectively, in pregnancies complicated by IUGR, and those complicated by both IUGR and preeclampsia. However, a single blood sample of activin A was unable to distinguish between IUGR and SGA pregnancies with sufficient sensitivity to be clinically useful. Our studies were unable to demonstrate clinical utility for the experimental observation linking activin A and hypoxia.

Maternal serum activin A and the prediction of intrauterine growth restriction

BACKGROUND

Differentiating between the small healthy fetus and the high risk growth restricted fetus remains a significant obstetric challenge. It has been previously shown that maternal activin A levels are increased in association with fetal growth restriction.

AIM

To evaluate maternal serum activin A as a marker of fetal growth restriction.

METHODS

Prospective cohort study of 62 women referred for fetal assessment because of a clinical suspicion of a small for gestation fetus. Maternal serum levels of activin A were measured with an ELISA.

RESULTS

Activin A levels, expressed as median (95% CI) MoMs, were similar in the women with a normal-sized fetus and in those with a healthy small for gestational age fetus, 1.14 (95% CI 1.0-1.5) and 1.31 (95% CI 0.8-2.1), respectively (P = 0.97). Compared to the women with a normal-sized fetus or a healthy small fetus, activin A levels were significantly elevated in the women who had an intrauterine fetal growth restriction fetus 2.37 (95% CI 1.6-3.7; P = 0.01 compared to normal and P = 0.04 compared to healthy small).

CONCLUSIONS

These data confirm that circulating activin A is increased in association with fetal growth restriction. However, a single blood sample for activin A will not efficiently discern between healthy and compromised small fetuses.

Ratio of circulating follistatin and activin A reflects the severity of acute liver injury and prognosis in patients with acute liver failure

BACKGROUND AND AIM

The activin A-follistatin system is known to play a critical role in hepatocyte regeneration during the repair of liver tissue. However, the relationship between blood levels of these compounds and the severity and prognosis of acute liver injury remains unclear. The aim of this study was to evaluate the clinical significance of circulating activin A and follistatin in patients with acute liver disease.

METHODS

Serum activin A and plasma follistatin levels were determined on admission by enzyme-linked immunosorbent assay in 32 patients with acute hepatitis (AH), 23 patients with acute severe hepatitis (ASH) and 16 patients with acute liver failure (ALF).

RESULTS

Both serum activin A and plasma follistatin levels were significantly elevated in patients with ASH and ALF when compared with those in patients with AH and normal controls (NC). Although plasma follistatin levels were significantly and positively correlated with serum activin A levels (r = 0.413, P < 0.001), the follistatin and activin A (F/A) ratio showed distinct deviation from NC between AH and ALF patients. The F/A ratio in AH patients was significantly elevated when compared with NC, but was significantly reduced in ALF patients. Furthermore, the F/A ratio in non-surviving ALF patients was significantly lower than that in survivors. Levels of serum activin A and plasma follistatin were significantly and negatively correlated with prothrombin time (PT) and normotest (NT) levels, while the F/A ratio showed significant and positive correlations with PT and NT.

CONCLUSIONS

Decreased blood F/A ratio in ALF patients may be a reliable indicator of the severity of acute liver injury and prognosis in ALF.

Chronic fetal hypoxia increases activin A concentrations in the late-pregnant sheep

OBJECTIVE

To determine whether activin A concentrations are altered in chronic fetal hypoxemia and intrauterine fetal growth restriction (IUGR).

DESIGN

In vivo animal experimental model.

SETTING

Department of Physiology, Monash University.

POPULATION

Chronically catherised fetal sheep in late pregnancy.

METHODS

Chronic fetal hypoxia and IUGR were experimentally induced by single umbilical artery ligation (SUAL) in catheterised fetal sheep. Maternal and fetal blood samples and amniotic fluid (AF) samples were collected during surgery and thereafter on alternate days, until the time of delivery for analyte measurement. Fetal blood gas parameters were measured daily.

MAIN OUTCOME MEASURES

Plasma and AF was used to analyse activin A, prostaglandin E2 (PGE2) and cortisol and fetal blood gas analysis was undertaken in whole blood.

RESULTS

SUAL produced asymmetric IUGR and non-acidaemic chronic fetal hypoxia and resulted in preterm labour (129 [3] days). AF activin A concentrations were 10-fold higher in the SUAL group than in controls whereas levels in the fetal and maternal circulations were similar between groups.

CONCLUSIONS

SUAL-induced IUGR and fetal hypoxaemia increases AF activin A. This may be an important adaptive or protective response to IUGR.

Total activin A in maternal blood as a marker of preterm delivery in low-risk asymptomatic patients

OBJECTIVES

To retrospectively evaluate whether increased serum levels of total activin A (t-activin A) are found in women who subsequently experience preterm delivery (PTD).

METHODS

Data on maternal serum t-activin A concentrations were available from a total of 84 singleton pregnant women and included 14 PTD pregnancies, each matched for gestational age and length of freezer storage, with 5 control pregnancies having term delivery (TD). Analyte values were expressed as multiple(s) of the control median.

RESULTS

The median t-activin A for controls and cases was 1.00 +/- 0.45 and 1.27 +/- 0.53 MoM, respectively. Univariate analysis of the MoM values was performed using the Kaplan-Meier algorithm. Differences in the rate of delivery using a t-activin A MoM cut-off of > or = 1 SD (equivalent to 1.26 MoM) were analysed using the log rank test. The cumulative rate of PTD (< 37 weeks) was significantly higher for women with t-activin A concentrations > or = 1.26 MoM than those with t-activin A concentrations below this cut-off (40% vs.. 10%, p-value = 0.0218 log rank test).

CONCLUSIONS

T-activin A concentration is higher in women who will develop PTD in a low-risk population. T-activin A values are inversely proportional to the time elapsed from blood test to delivery. Prospective studies would determine the precise discriminability of this marker for PTD and the best week for performing the blood test, allowing for a proper calculation of the detection rate and a positive predictive value.

Serum levels of activin A and inhibin A are not related to the increased susceptibility to pre-eclampsia in type I diabetic pregnancies

BACKGROUND

Activin A and inhibin A have been found to be elevated in women without diabetes subsequently developing pre-eclampsia. The aim was to investigate whether activin A and inhibin A in serum were elevated in type I diabetic women after developing pre-eclampsia and, if so, were they clinically useful as predictors of pre-eclampsia.

METHODS

In a prospective study, maternal serum was analyzed for activin A and inhibin A in 115 women with type 1 diabetes at 10, 14, 22, 28, and 33 weeks of gestation.

RESULTS

Fourteen women (12%) developed pre-eclampsia (26-37 weeks of gestation) and 101 did not. The two groups were comparable regarding age, body mass index, and diabetes duration. There was no difference between serum concentrations of activin A and inhibin A in women developing pre-eclampsia and women who did not at any gestational period.

CONCLUSIONS

Serum concentrations of activin A and inhibin A could not predict preeclampsia in type I diabetes.

Preliminary prospective study of the endocrinology of conception cycles and early pregnancy in women with antiphospholipid syndrome treated with low molecular weight heparin

OBJECTIVE

To examine whether there were any differences in the endocrinological profiles during conception cycle and early pregnancy between a control group and women with a history of recurrent miscarriage that was caused by antiphospholipid syndrome and that was treated with aspirin and low molecular weight heparin.

DESIGN

Prospective observational study.

SETTING

Recurrent Miscarriage Clinic, Department of Obstetrics and Gynaecology in a tertiary care centre.

PATIENT(S)

Five women with recurrent pregnancy loss were recruited as cases, whereas another five women having natural cycle donor insemination were used as control.

INTERVENTION(S)

Serial measurement of serum beta-hCG, activin A, and inhibin A was performed from postovulatory day 12 until 11 weeks of gestation.

MAIN OUTCOME MEASURE(S)

Comparison of levels of beta-hCG, activin A, and inhibin A at the time of conception onwards till 11 weeks in the two groups.

RESULT(S)

There were no significant differences between the two groups.

CONCLUSION(S)

There does not appear to be any obvious endocrinological alteration in the conception cycle of women with antiphospholipid syndrome compared with a control group. Furthermore, the initiation of heparin does not produce a significant change in activin A and inhibin A levels.

Examination of Maternal Plasma Erythropoietin and Activin A Concentrations with Regard to Circulatory Erythroblast Levels in Normal and Preeclamptic Pregnancies

OBJECTIVES

Preeclampsia has been shown to be associated with an increased number of fetal and maternal erythroblasts in the maternal circulation, suggesting that preeclampsia involves increased leakage of fetal cells across the placental barrier, as well as increased erythropoiesis. We examined the relationship between circulatory erythroblast levels with maternal plasma concentrations of erythropoietin and activin A.

METHODS

In a case-control study, we examined 15 pregnancies affected by preeclampsia and 10 matched controls. Erythroblasts were enriched from maternal blood samples by magnetic cell sorting, enumerated and correlated with corresponding plasma activin A and erythropoietin concentrations.

RESULTS

The proportion of erythroblast was elevated in preeclampsia (0.8 vs. 0.1%, p = 0.023). Erythropoietin and activin A concentrations were significantly elevated in preeclampsia (100.4 vs. 44.5 pg/ml, p = 0.023, and 7.4 vs. 1.85 ng/ml, p = 0.029, respectively). Circulatory erythroblast numbers were found to correlate with plasma activin A concentrations (r = 0.76, p = 0.01) in cases with preeclampsia. No such relationship existed for erythropoietin.

CONCLUSIONS

Our data suggest that increased concentrations of activin A promote enhanced levels of erythropoiesis in preeclampsia. As the placenta is one of the major sources of activin A in pregnancy, this increase in activin A-dependent erythropoiesis in preeclampsia may be a reflection of an underlying placental hypoxic condition.

Activin A is an acute allergen-responsive cytokine and provides a link to TGF-beta-mediated airway remodeling in asthma

BACKGROUND

Allergic asthma typically shows activated, allergen-specific CD4(+) T cells in the early phase and airway remodeling in the late phase of the disease. Although TGF-beta plays a crucial role in airway remodeling, it is only marginally induced in CD4(+) T cells in the early allergen-dependent activation of the immune system.

OBJECTIVE

To elucidate the transition between early- and late-phase events, we investigated the role of activin A, a close family member of TGF-beta.

METHODS

Activin A and TGF-beta(1) levels were measured systemically in the serum and in CD4(+) T cells of asthmatic patients, as well as locally in the lung.

RESULTS

Activin A serum levels were increased in patients with severe asthma compared with levels in patients with moderate asthma and healthy control subjects, whereas all patients showed significantly increased TGF-beta(1) serum levels independent of disease severity. In T cells only patients with moderate asthma showed increased activin A mRNA expression, whereas TGF-beta(1) expression was equal to that seen in healthy subjects. Accordingly, ovalbumin sensitization in a mouse model of allergic asthma could induce activin A mRNA expression, but not TGF-beta(1) expression, in the lung. Immunohistochemistry of mice and human specimens revealed an abundant expression of activin A by infiltrating lymphocytes and structural cells of the lung. Although TGF-beta(1) more potently enhanced proliferation and Smad 2/3-dependent reporter genes in fibroblasts, activin A was capable of inducing TGF-beta(1) and vice versa.

CONCLUSION

Activin A provides a link between acute allergen-specific T-cell responses and chronic TGF-beta(1)-mediated airway remodeling in asthma.

Screening for pre-eclampsia by using maternal serum inhibin A, activin A, human chorionic gonadotropin, unconjugated estriol, and alpha-fetoprotein levels and uterine artery Doppler in the second trimester of pregnancy

AIMS

To analyse the predictive power of maternal serum inhibin A, activin A, human chorionic gonadotropin (hCG), unconjugated estriol (uE(3)), alpha-fetoprotein (AFP) levels and uterine artery Doppler in the second trimester of pregnancy in screening for pre-eclampsia.

METHODS

Maternal serum inhibin A, activin A, hCG, uE(3), and AFP levels and uterine artery Doppler were determined in 178 healthy, pregnant women in the second trimester of pregnancy. Serum samples were collected between the 16th and 18th weeks of gestation, and Doppler investigation was performed between the 24th and 26th weeks of gestation. Receiver operating characteristic curves were created to analyse the predictive powers of the above parameters in screening for pre-eclampsia. Different combinations also were analysed.

RESULTS

The rate of pre-eclampsia was 7.9% (14/178). Maternal serum inhibin A, activin A, hCG, AFP levels, the rate of presence of the prediastolic notch and uterine artery resistance index (RI) values in pre-eclamptic pregnancies were significantly higher than those in healthy pregnancies. Presence of the prediastolic notch, uterine artery RI, maternal serum activin A and inhibin A levels had high predictive efficacy, and each had a sensitivity between 70 and 93% and a specificity between 87% and 98%. The addition of inhibin A or activin A measurement to the Doppler velocimetry improved the specificity to 99-100%.

CONCLUSIONS

Maternal serum inhibin A and activin A levels and uterine artery Doppler appear to be useful screening tests during the second trimester for pre-eclampsia. However, addition of these hormonal markers to Doppler velocimetry only slightly improves the predictive efficacy, which appears clinically insignificant.

Inhibin A and activin A may be used to predict pregnancy outcome in women with recurrent miscarriage

OBJECTIVE

To look at the role of inhibin and activin in predicting pregnancy outcome in patients with history of recurrent miscarriage.

DESIGN

Observational clinical study.

SETTING

Recurrent miscarriage clinic of a tertiary care teaching hospital.

PATIENT(S)

Patients with history of recurrent miscarriage.

INTERVENTION(S)

Serial serum inhibin A and activin A concentrations were measured in weeks 5 though 8 of pregnancy.

MAIN OUTCOME MEASURE(S)

Serum concentrations of inhibin A and activin A levels.

RESULT(S)

Mean inhibin A concentration at 5 to 6 weeks for women who miscarried and those who had live births was 33 and 51 pg/mL, respectively; activin A at same gestation for the two groups was 534 and 643 pg/mL, respectively. After 2 weeks, mean inhibin A concentration for women who miscarried and those who had live births was 66 and 145 pg/mL, respectively, and activin A was 747 and 1,123 pg/mL, respectively.

CONCLUSION(S)

It is possible that inhibin A and activin A may be used as markers to predict pregnancies that are likely to miscarry.

Prediction of preeclampsia with maternal mid-trimester placental growth factor, activin A, fibronectin and uterine artery Doppler velocimetry

OBJECTIVE

To assess whether alterations in the serum levels of placental growth factor, activin A and fibronectin could be detected in patients before they become preeclamptic. And to evaluate and compare the clinical utility of these markers and uterine artery Doppler velocimetry in predicting preeclampsia.

METHODS

One hundred and twenty-two normotensive women were prospectively included in the study. Peripheral venous blood samples were obtained and Doppler examination of the uterine arteries was performed between 21 and 26 weeks' gestation. Serum levels of placental growth factor, activin A and fibronectin were measured by enzyme-linked immunoassay and radial immundiffusion technic.

RESULTS

Mid-trimester maternal serum activin A and fibronectin levels and average S/D ratios were significantly higher whereas placental growth factor levels were significantly lower in women who subsequently developed preeclampsia than remained normotensive (p<0.001). The best cut-off values for predicting preeclampsia of placental growth factor, activin A and fibronectin based on ROC curve analysis were 90 pg/ml, 14 ng/ml and 370 mg/l respectively. The areas under the curve equal to 0.993, 0.972, 0.872 and 0.813 for placental growth factor, activin A, fibronectin and uterine artery Doppler respectively were determined for the prediction of preeclampsia.

CONCLUSION

Placental growth factor, activin A, fibronectin and uterine artery Doppler are all potentially useful as predictors of preeclampsia. Maternal serum midtrimester PGF has the highest predictive value and activin A with a compatible accuracy for early identification of preeclampsia.

Effects of age and pregnancy on the circulatory activin response of sheep to acute inflammatory challenge by lipopolysaccharide

The release of activin A in response to intravenous injection of the bacterial cell-wall component lipopolysaccharide (LPS) was investigated in an ovine model of acute inflammatory challenge in newborn and adult sheep, and in non-pregnant and pregnant ewes. Neonatal lambs (<20 days of age) showed a quantitatively similar response in terms of circulating concentrations of activin A, its binding protein follistatin and the cytokine interleukin-6 compared with adult ewes challenged with an equivalent dose (300 ng/kg bodyweight) of LPS. The fever response and plasma tumour necrosis factor-alpha release in response to LPS, however, were significantly (P < 0.01) less in lambs than in the adult group. Pregnant ewes in the last trimester of gestation had similar responses to LPS, in all aspects measured, compared with their non-pregnant counterparts, apart from an ablated fever response. Although the adult and neonatal sheep responded to LPS, a similar response was not apparent in the fetal circulation, possibly due to a protective effect of the placenta. A 10-fold increase in the dose of LPS (from 300 ng to 3 microg/kg bodyweight) given to neonatal lambs elicited an increase in several cytokine responses measured, with a significant (P< 0.05) increase in follistatin release. In contrast, the amount of activin released by the increased dose of LPS was similar to that invoked by the lower dose. The effect of tolerance to LPS was investigated by giving a second challenge of LPS 5 days after the initial injection. In all animals studied, there was an ablated (P < 0.05) response to the subsequent LPS injection, apart from a similar temperature-response profile. These data provide further evidence that activin A concentrations in the bloodstream are acutely responsive to inflammatory challenge in post-natal life and suggest that the response forms a significant component of the innate immune system.

Diurnal changes in FSH-regulatory peptides and their relationship to gonadotrophins in pubertal girls

BACKGROUND

FSH-regulatory peptides participate with GnRH and sex steroids to regulate serum FSH concentrations. We hypothesized that day/night variations in FSH serum concentrations would be associated with diurnal variation in FSH-regulatory peptides.

METHODS

Blood was obtained every 15 min for 24 h beginning at 08:00 h in eight girls [seven with variations in growth or puberty and one with idiopathic hypogonadotrophic hypogonadism (IHH)] and for 12 h beginning at 20:00 h in 12 additional girls with variant puberty, eight with gonadal dysgenesis or ovarian failure (GD/OF) and one with IHH. Samples across 3 h blocks were pooled for determination of LH, FSH, activin-A, inhibin-B and follistatin 288.

RESULTS

LH and FSH concentrations increased from 23:00 to 08:00 h with respect to daytime concentrations in pubertal girls (P<0.005) but only LH increased (P=0.002) in girls with GD/OF. In pubertal girls, inhibin-B declined during the day (P=0.019), reaching a nadir between 17:00 and 22:45 h just prior to the night-time increase in FSH. Follistatin concentrations exhibited diurnal variation (P=0.028), with the greatest concentrations occurring between 05:00 and 11:00 h. Activin-A concentrations declined coincident with the night-time increase in FSH in pubertal girls (P<0.0001) but not in girls with GD/OF.

CONCLUSIONS

The directionality of changes in FSH-regulatory proteins supports the notion that FSH-regulatory peptides may contribute to the night-time augmentation of circulating FSH during puberty in girls.

GnRH agonist stimulation of the pituitary–gonadal axis in children: age and sex differences in circulating inhibin-B and activin-A

BACKGROUND

Inhibin-B decreases and activin increases FSH secretion in adults. We investigated whether an FSH-inhibin/activin feedback loop exists before or during puberty.

METHODS

FSH secretion was stimulated with 10 microg/kg leuprolide acetate (GnRH agonist) in 18 girls, ages 1.0-13.2 years, and 11 boys, ages 8.9-15.2 years, with variations in pubertal development, and in five normal 9- to 10-year-old girls. Blood, obtained at 0, 0.5, 1, 2, 4, 8, 12, 16, 20 and 24 h after GnRH agonist, was analysed for LH, FSH, activin-A, inhibin-A, inhibin-B, follistatin 288 and estradiol/testosterone.

RESULTS

FSH increased within 30 min of GnRH agonist administration with a peak greater in girls than boys (P=0.0006). Baseline inhibin-B was greater in boys than girls (P=0.01), while baseline activin-A concentrations were greater in girls. GnRH agonist-stimulated FSH increased inhibin-B in girls by 8 h and in boys by 20 h (P<0.05), but did not affect activin-A. Inhibin-B increases were seen only in girls older than 5 years.

CONCLUSIONS

An inhibin-B-FSH feedback loop exists prior to the onset of puberty in girls older than 5 years. Sex differences in activin-A and inhibin-B concentrations may be responsible for sex differences in serum FSH concentrations.

Circulating levels of inhibin A, inhibin B and activin A in normal and intrauterine growth restricted (IUGR) fetuses

OBJECTIVE

To evaluate the relationships between circulating levels of inhibin A, inhibin B and activin A, and sex, gestational age and gonadotropins in normal and pathological fetuses.

STUDY DESIGN

The study included 31 normal fetuses and 12 affected with intrauterine growth restriction (IUGR) of gestational age ranging 20-40 weeks.

RESULTS

No gender difference in inhibin A and activin A levels were observed. Inhibin B levels were significantly higher in males than in females (P < 0.05). Fetuses with the highest levels of inhibin A and B were found in the IUGR group that also showed activin A levels significantly higher than normal. No correlations were observed between inhibin A, inhibin B, activin A and both gonadotropins.

CONCLUSION

Plasma inhibin A, inhibin B and activin A are detectable in both genders during intrauterine life. The different gender pattern of inhibin B suggests that inhibin B may contribute to the assessment of the hypothalamic-pituitary-gonadal set-point at least in males.

Activin A and follistatin in systemic inflammation

Inflammation is a complex process regulated by a cascade of cytokines and growth factors. This review summarizes the emerging evidence implicating activin A and follistatin in the inflammatory process. Our recent studies have highlighted that activin A is released early in the process as part of the circulatory cytokine cascade during acute systemic inflammation. This release occurs concurrently with tumor necrosis factor (TNF)-alpha and prior to that of interleukin (IL)-6 and follistatin. Although, the cellular source(s) of activin A are yet to be established, circulating blood cells and the vascular endothelium are candidates for this rapid release of activin A into the circulation. The release of activin A and follistatin is also observed in the clinical setting, in particular in sepsis. Furthermore activin A is released into cerebrospinal fluid in a model of meningitis in rabbits. The role of activin A in the inflammatory response is poorly understood, however, in vitro data has highlighted that activin A can have both pro- and anti-inflammatory actions on key mediators of the inflammatory response such as TNF-alpha, IL-1beta and IL-6. Furthermore, emerging data would suggest that activin A induction is restricted to certain types of inflammation and its release is dependant upon the inflammatory setting.

Influence of mutations affecting gonadotropin production or responsiveness on expression of inhibin subunit mRNA and protein in the mouse ovary

Measurement of inhibins A and B in the serum of normal cyclic rodents has implicated FSH in the regulation of these peptides within the ovary. To extend these observations we have used a panel of mutant mice carrying mutations which affect either the production of, or the ability to respond to, FSH and LH. As a consequence, the females are infertile and show different degrees of follicular development. The aim of this study was to measure inhibin gene transcription in the ovaries of these mutant females together with inhibin protein levels in ovaries and serum and to relate these to follicular development within the ovary. Comparison was made with a pool of normal/heterozygous females. In hpg females where lack of GnRH production results in the absence of gonadotropin synthesis, in FSHbeta knockout (FSHbetaKO) females where disruption of the gene encoding FSHbeta results in the absence of FSH production, and in FSH receptor knockout (FSHRKO) females which are unable to respond to circulating FSH, follicular development remains at the pre-antral stage in these three mutants. Only in the hpg females were common inhibin alpha subunit mRNA levels significantly lower than normal. In these three mutants, however, mRNA levels for both the betaA and betaB subunits were extremely low compared with normal mice. At the protein level, neither inhibin A nor B was detected in the serum of these three mutants; however inhibin B, albeit at very low levels, was detectable within the ovaries. These observations confirm a major role for FSH in the control of transcription of the betaA and betaB genes but suggest that the constitutive transcription of the alpha subunit is less dependent on FSH. In contrast, in LH receptor knockout (LuRKO) female mice inhibin betaA subunit mRNA levels were similar to those measured in normal/heterozygous females but levels of inhibin alpha and betaB subunit mRNAs were significantly higher than in the normal group. This was reflected in significantly higher inhibin B protein levels in ovaries and serum. An inability to respond to LH combined with high circulating levels of FSH leads to a high proportion of antral follicles in LuRKO females, with granulosa cells constituting the major cell type within the ovary. The high percentage of antral granulosa cells is likely to account for the significantly higher levels of inhibin B production in these ovaries.

Adhesion molecules, activin and inhibin--candidates for the biochemical prediction of hypertensive diseases in pregnancy?

BACKGROUND

The aim of the prospective study was to compare standard parameters as Doppler ultrasound and 24-h blood pressure measurement with possible maternal serological markers regarding their prognostic value in predicting hypertensive diseases in pregnancy.

MATERIALS

Twenty-four-hour blood pressure measurement was performed before and after 32+0 gestational week in 57 pregnant women with either chronic hypertension ( n=13), preeclampsia ( n=21), pregnancy-induced hypertension (PIH; n=12) or normotension ( n=11). Blood samples were taken and the concentrations of soluble intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), activin A and inhibin A were determined as well as serum uric acid, creatinine, total serum protein and serum albumin. Doppler ultrasound of the uterine arteries was examined before 32+0 gestational week in the same patients. For the statistical evaluation Kruskal-Wallis-Test and Mann-Whitney-U-Test were performed. Differences in the predictive value were evaluated by receiver-operating characteristics.

RESULTS

VCAM-1 was significantly elevated in women developing hypertensive diseases as compared to normotensive women (preeclampsia: p<0.001; PIH: p<0.05; chronic hypertension: p<0.001). In early pregnancy activin A and inhibin A were significantly higher in preeclamptic patients than in the other groups (activin A: normotension: p<0.005; PIH: p<0.001; chronic hypertension: p<0.005) (inhibin A: normotension: p<0.005; PIH: p<0.001; chronic hypertension: p<0.01), thus suggesting them to be specific markers for the development of preeclampsia. Mean arterial pressure was significantly elevated in preeclampsia ( p<0.001) and chronic hypertension ( p<0.005) as compared to normotensives.

CONCLUSION

Twenty-four-hour blood pressure monitoring with determination of mean arterial pressure and measurement of VCAM-1, activin A and inhibin A as serum parameters can be suggested as useful tests in the specific prediction of different types of hypertensive diseases in pregnancy.

Potential anti-inflammatory role of activin A in acute coronary syndromes

OBJECTIVES

We sought to investigate whether activin A could be involved in the immunopathogenesis of acute coronary syndromes.

BACKGROUND

Inflammatory mechanisms seem to play a pathogenic role in atherosclerosis and acute coronary syndromes, but the actual mediators have not been fully identified. Activin A, a pleiotropic member of the transforming growth factor-beta cytokine family, has recently been suggested to play a role in inflammation.

METHODS

We examined the role of activin A and its endogenous inhibitor follistatin in patients with stable (n = 26) and unstable angina (n = 20) and healthy control subjects (n = 20) by different experimental approaches.

RESULTS

1) Patients with stable angina had raised activin A concentrations, as assessed by protein levels in serum and messenger ribonucleic acid levels in peripheral blood mononuclear cells (PBMCs). 2) Although several activin A-related mediators were upregulated in PBMCs from patients with stable angina compared with controls (i.e., activin A and Smad3), no changes or even downregulation (i.e., Smad2) were seen in unstable disease. 3) The activin type II receptors, representing the primary ligand-binding proteins, were downregulated in unstable compared with stable angina. 4) Percutaneous coronary intervention induced a decrease in the activin A/follistatin ratio, suggesting downregulatory effects on activin A activity. 5) Although activin A dose-dependently suppressed the release of inflammatory cytokines from PBMCs in angina patients, an opposite effect was found in healthy controls.

CONCLUSIONS

Our findings suggest an anti-inflammatory potential of activin A in angina patients, and such effects may be of particular relevance in unstable angina in which several of the activin parameters were downregulated.

Characterisation of the rapid release of activin A following acute lipopolysaccharide challenge in the ewe

A series of experiments were conducted in adult ewes to delineate the release profile of activin A and its relationship to other cytokines following an i.v. injection of the bacterial cell wall component, lipopolysaccharide (LPS). Following this challenge, plasma activin A increased rapidly and appeared to be released in a biphasic manner, slightly preceding the release of tumour necrosis factor-alpha (TNFalpha) and before elevation of interleukin (IL)-6 and follistatin levels. The concentration of activin A was correlated with body temperature during the response to LPS. A second experiment compared cytokine concentrations in matched blood and cerebrospinal fluid (CSF) samples. This revealed that activin A was not released centrally in the CSF following a peripheral LPS injection, nor was TNFalpha or the activin binding protein, follistatin, but IL-6 showed a robust elevation. In a third experiment, the stimulus for activin A release was examined by blocking prostaglandin synthesis. Flurbiprofen, a prostaglandin synthesis inhibitor, effectively attenuated the fever response to LPS and partly inhibited cortisol release, but the cytokine profiles were unaffected. Finally, the bioactivity of TNFalpha and/or IL-1 was blocked using soluble receptor antagonists. These treatments did not affect the initial release of activin A, but blockade of TNFalpha depressed the second activin peak. These studies define more rigorously the release of activin A into the circulation following acute inflammatory challenge. The response is rapid and probably biphasic, independent of prostaglandin- mediated pathways and does not depend upon stimulation by TNFalpha or IL-1. The data suggest that activin A release is an early event in the inflammatory cascade following the interaction of LPS with its cellular receptor.

Sex differences in FSH-regulatory peptides in pubertal age boys and girls and effects of sex steroid treatment

BACKGROUND

FSH concentrations are higher in girls than in boys before puberty. We hypothesized that steroid-mediated changes in FSH-regulatory proteins underlie the sex differences in FSH secretion and pubertal timing.

METHODS

FSH-regulatory proteins, LH, FSH and sex steroids were measured in five boys, 10 girls, and five girls with Turner syndrome before and during sex steroid treatment (girls, 0.05 mg/day estradiol; boys, 5 mg/day testosterone) for up to 4 weeks. Blood was obtained every 15 min from 20.00 to 08.00 h before and during sex steroid treatment.

RESULTS

The mean FSH concentration was higher in girls than in boys (P = 0.0044). Activin-A concentrations were greater (P < 0.0001) and inhibin-B concentrations lower (P < 0.0001) in girls compared with boys. Steroid treatment (i) suppressed LH/FSH concentrations in all subjects; (ii) increased the mean activin-A concentration in all but the Turner girls (P = 0.001); and (iii) decreased inhibin-B concentrations in boys (P = 0.005) but not in girls. Total follistatin and follistatin 288 concentrations did not differ by sex.

CONCLUSIONS

Sex steroids regulate circulating activin-A and inhibin-B concentrations in children. The lower inhibin-B and higher activin-A concentrations may explain the higher FSH and earlier onset of puberty in girls.

Changes in circulating and testicular levels of inhibin A and B and activin A during postnatal development in the rat

This study describes the testicular levels of inhibin/activin subunits by Northern analysis and in situ hybridization and serum and testicular levels of inhibins A and B and activin A by enzyme linked immunosorbent assays (ELISA) during postnatal development in the rat. We show that serum inhibin A levels are less than 4 pg/ml throughout postnatal life. Serum inhibin B levels peak at 572 +/- 119 pg/ml (mean +/- se) at d 40 post partum (pp) before falling to 182 +/- 35 pg/ml in mature males. Serum activin A decreases from 294 +/- 29 pg/ml at d 6 to 132 +/- 27 pg/ml at maturity. Within the testis, inhibin A levels fall from 0.330 +/- 0.108 ng/g at d 15 to less than 0.004 ng/g at maturity. Inhibin B levels peak at 43.9 +/- 4.2 ng/g at d 6 before falling to 1.6 +/- 0.13 ng/g at maturity. Testicular activin A levels fall from 18.6 +/- 2.2 ng/g at d 6 to 0.094 +/- 0.013 ng/g at maturity. Northern profiles of testicular inhibin/activin subunits correlate with immunoreactive levels demonstrated by ELISA. In situ hybridization suggests that beta(A) and beta(B) subunit expression is largely restricted to the seminiferous tubule, particularly Sertoli cells, spermatogonia, and primary spermatocytes. These data support the view that inhibin B is the major inhibin in the male rat and that levels relate to Sertoli cell number and activity. Furthermore, the demonstration of high local concentrations of activin A during the period of Sertoli cell proliferation and the onset of spermatogenesis support its proposed role because a modulator of testicular development and function.