Maternal Serum B-Cell Activating Factor Levels

Serum BAFF (B-cell activating factor) and APRIL (a proliferation-inducing ligand) levels in the first trimester may predict the future development of gestational diabetes mellitus

BACKGROUND

Gestational diabetes mellitus (GDM) is a prevalent condition with an unclear pathogenesis. B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are potential key players in GDM.

PARTICIPANTS, MATERIALS, AND METHODS

In a longitudinal observational study, we monitored women from the first trimester through 24-28 weeks of gestation, focusing on the development of GDM. Serum levels of BAFF and APRIL, as well as their mRNA expression, were evaluated in both the first and third trimesters. Furthermore, we assessed cytokines, adipokines, and placental hormones in the serum.

RESULTS

In the first trimester, participants who later developed GDM exhibited elevated serum BAFF and reduced serum APRIL levels, although the mRNA expression of these molecules was similar to controls. Serum BAFF exhibited significant positive correlations with metabolic markers and placental hormones. Conversely, serum APRIL was negatively correlated with insulin resistance and inflammatory markers but positively correlated with adiponectin. In the early third trimester, GDM participants continued to display higher serum BAFF levels and lower serum APRIL levels than controls. There was no significant difference in mRNA expression of BAFF between GDM and control groups. Conversely, APRIL mRNA expression was significantly lower in the GDM group. The predictive potential of first-trimester BAFF and APRIL levels for future GDM development was explored, with both molecules demonstrating strong predictive capability.

DISCUSSION AND CONCLUSION

This study suggests that elevated serum BAFF and reduced serum APRIL levels during pregnancy may be associated with the development of GDM. These biomarkers can serve as potential early predictors for GDM.

Physiological Changes in the Levels of Anti-Cytokine Autoantibodies in Early Pregnancy Are Missing in Pregnant Women with Hashimoto's Thyroiditis

T helper type 1 (Th1) and inflammatory cytokines play essential roles in early pregnancy and also in the pathogenesis of Hashimoto's thyroiditis (HT). Changes in the serum level of autoantibodies to cytokines, which may be able to modulate their availability and actions have been described in several autoimmune disorders. Yet, no data are available on anti-cytokine autoantibodies either during early pregnancy or in patients with HT. The aim of the study was to measure autoantibodies to inflammatory-, Th1- and Th22-cytokines in serum samples in healthy pregnancy (HP) and in pregnant women with HT (HTP). As pathological autoantibodies are hallmarks of HT, in addition we also measured anti-B-cell activator factor (BAFF) autoantibodies. The measurement was carried out with a Luminex multiplex assay and the Luminex MAGPIX Instrument, age-matched healthy women (HC) and women with HT (HT) were used as controls. In the first trimester of HP, anti-TNFα, anti-IL-8, and anti-IFNγ autoantibodies were significantly decreased, while autoantibodies to BAFF were significantly elevated compared to the HC. However, these alterations were not present in the HTP. Moreover, the levels of autoantibodies to IL-22 and TNFα were significantly increased in HTP compared to the HP. All differences in the levels of the investigated autoantibodies could be detected in the first trimester of pregnancies except for anti-IL-22 autoantibodies. According to our results we can conclude that alterations in the levels of autoantibodies to inflammatory and Th1 cytokines are physiological in the first trimester of pregnancy and their disturbance can be associated with autoimmune conditions such as HT.

BAFF and APRIL counterregulate susceptibility to inflammation-induced preterm birth

Clinical evidence points to a function for B cell-activating factor (BAFF) in pregnancy. However, direct roles for BAFF-axis members in pregnancy have not been examined. Here, via utility of genetically modified mice, we report that BAFF promotes inflammatory responsiveness and increases susceptibility to inflammation-induced preterm birth (PTB). In contrast, we show that the closely related A proliferation-inducing ligand (APRIL) decreases inflammatory responsiveness and susceptibility to PTB. Known BAFF-axis receptors serve a redundant function in signaling BAFF/APRIL presence in pregnancy. Treatment with anti-BAFF/APRIL monoclonal antibodies or BAFF/APRIL recombinant proteins is sufficient to manipulate susceptibility to PTB. Notably, macrophages at the maternal-fetal interface produce BAFF, while BAFF and APRIL presence divergently shape macrophage gene expression and inflammatory function. Overall, our findings demonstrate that BAFF and APRIL play divergent inflammatory roles in pregnancy and provide therapeutic targets for mitigating risk of inflammation-induced PTB.

Maternal and cord blood BAFF and APRIL levels during pregnancy

PROBLEM

Dysregulation of factors vital to the survival B cells and/or plasma cells, such as BAFF and APRIL, could be detrimental to a pregnancy.

METHOD OF STUDY

Serially collected first-, second-, and third-trimester serum samples were measured for BAFF and APRIL by ELISA from 150 pregnant women (71 healthy + 79 with a chronic medical disease) at a single medical center. Postpartum serum samples were also collected from the majority of these women. Matched third-trimester and cord blood samples were collected from 168 women (86 healthy + 82 with a chronic medical disease). Data were analyzed by chi-square statistic, unpaired t-test, paired t-test, Mann-Whitney rank sum test, Wilcoxon signed rank test, Spearman rank order correlation, and receiver operator characteristic (ROC) curve analyses as appropriate.

RESULTS

Maternal serum BAFF levels declined as the pregnancies progressed and rebounded postpartum, whereas serum APRIL levels remained relatively flat throughout pregnancy and postpartum. Cord BAFF and APRIL levels correlated positively with gestation age and were considerably greater than the corresponding maternal third-trimester serum BAFF and APRIL levels, respectively. In women who developed preeclampsia, third-trimester BAFF levels were greater, rather than lower, than their corresponding second-trimester BAFF levels. ROC curve analysis suggested a potential role for third-trimester serum BAFF level as a biomarker of preeclampsia.

CONCLUSIONS

BAFF and APRIL are differentially regulated in the mother during and following pregnancy, whereas each is upregulated in the developing fetus. An increase in third-trimester serum BAFF level may portend development of preeclampsia.

Pregnancy outcomes in patients treated with belimumab: Report from real-world experience

OBJECTIVE

To investigate the neonatal and maternal outcomes of patients treated with belimumab during pregnancy.

MATERIALS AND METHODS

We retrospectively collected patients who were treated with belimumab during pregnancy from January 2018 to October 2020 in a tertiary referral hospital in Taiwan. All patients had clinical and serological features of systemic lupus erythematosus or antiphospholipid syndrome and had been treated accordingly. The patients' medical and obstetric history, obstetric complications and fetal outcomes were collected by chart review.

RESULTS

A total of 13 pregnancies in 13 patients were included. The median age was 38 years (interquartile range 32-41 years), 46.2% had a history of recurrent pregnancy loss, and the median number of treatment courses with belimumab (400 mg per dose) was two. There were 11 live births (84.6%, 11 of 13). One episode of omphalitis was noted in one fetus, who recovered well with antibiotic treatment. No fetus had leukopenia, lymphopenia, neutropenia, or thrombocytopenia in the days after birth. No fetal anomalies were found in this series. Among the six patients with a past history of recurrent pregnancy loss, four had live births.

CONCLUSION

This study provides new evidence for the use of belimumab in pregnant patients. No increase in the risk of fetal anomalies or severe infection was noted in the patients who were exposed to belimumab during pregnancy. Cautious monitoring is necessary if belimumab is used in pregnant patients, and more data are still needed to validate its safety.

First-trimester serum BAFF:sFlt-1 ratio as a candidate early biomarker of spontaneous abortion

PROBLEM

Immunologic, angiogenic, and anti-angiogenic factors are associated with spontaneous abortion (SAB). B cell-activating factor (BAFF), a proliferation-inducing ligand (APRIL), placental growth factor (PlGF), and soluble fms-like tyrosine kinase-1 (sFlt-1) may play a role in SAB and may serve singly or in combination as an early biomarker of SAB.

METHOD OF STUDY

In this prospective observational study, serum sFlt-1, PIGF, BAFF, and APRIL levels were measured in the first trimester of pregnancy in a medically diverse group of women and in non-pregnant controls. Associations and discriminative values of first-trimester sFlt-1, PIGF, BAFF, and APRIL levels and the corresponding APRIL:BAFF, BAFF:sFlt-1, and sFlt-1:PlGF ratios with development of SAB were tested.

RESULTS

Median serum BAFF level was lower (p = .007) and median serum sFlt-1 level was higher (p < .001), in the first trimester of pregnancy than in non-pregnant controls. SAB developed in 27 of the pregnant women (11.3%), and first-trimester levels of BAFF (but not APRIL) and sFlt-1 (but not PIGF) were associated with SAB. Using optimal cutoffs determined through receiver operating characteristics curves, the best discriminator of SAB was the serum BAFF:sFlt-1 ratio, specifically among non-nulliparous women and women with prior SAB.

CONCLUSION

First-trimester serum BAFF:sFlt-1 ratio is a candidate indicator/predictor of SAB among non-nulliparous women and women with prior SAB. If validated through additional studies, then early identification of pregnant women at high risk for SAB through this simple blood test would assist in counseling and facilitate clinical trials of therapeutic interventions.

Methylglyoxal, Glycated Albumin, PAF, and TNF-α: Possible Inflammatory and Metabolic Biomarkers for Management of Gestational Diabetes

Background: In gestational diabetes mellitus (GDM), pancreatic β-cell breakdown can result from a proinflammatory imbalance created by a sustained level of cytokines. In this study, we investigated the role of specific cytokines, such as B-cell activating factor (BAFF), tumor necrosis factor α (TNF-α), and platelet-activating factor (PAF), together with methylglyoxal (MGO) and glycated albumin (GA) in pregnant women affected by GDM. Methods: We enrolled 30 women whose inflammation and metabolic markers were measured at recruitment and after 12 weeks of strict dietetic therapy. We compared these data to the data obtained from 53 randomly selected healthy nonpregnant subjects without diabetes, hyperglycemia, or any condition that can affect glycemic metabolism. Results: In pregnant women affected by GDM, PAF levels increased from 26.3 (17.4–47.5) ng/mL to 40.1 (30.5–80.5) ng/mL (p < 0.001). Their TNF-α levels increased from 3.0 (2.8–3.5) pg/mL to 3.4 (3.1–5.8) pg/mL (p < 0.001). The levels of methylglyoxal were significantly higher in the women with GDM (p < 0.001), both at diagnosis and after 12 weeks (0.64 (0.46–0.90) μg/mL; 0.71 (0.47–0.93) μg/mL, respectively) compared to general population (0.25 (0.19–0.28) μg/mL). Levels of glycated albumin were significantly higher in women with GDM (p < 0.001) only after 12 weeks from diagnosis (1.51 (0.88–2.03) nmol/mL) compared to general population (0.95 (0.63–1.4) nmol/mL). Conclusion: These findings support the involvement of new inflammatory and metabolic biomarkers in the mechanisms related to GDM complications and prompt deeper exploration into the vicious cycle connecting inflammation, oxidative stress, and metabolic results.

B cell activation factor (BAFF) induces inflammation in the human fallopian tube leading to tubal pregnancy

Background

Tubal pregnancy is recognized as one of the most common ectopic pregnancy types. Salpingitis may result in tubal pregnancy by causing fallopian tube occlusion and hydrosalpinx. B cell activation factor (BAFF) is a proinflammatory cytokine that helps regulate both innate and adaptive immune responses. Our previous study firstly showed that BAFF immunostaining appeared on the cellular membrane and in the cytoplasm of tubal epithelial cells, and both BAFF protein and mRNA in human inflamed fallopian tubes had higher expression levels than those in normal fallopian tubes. This study aimed to elucidate the association between the expression of BAFF gene and the inflammation in the human fallopian tube leading to tubal pregnancy.

Methods

We examined 70 patients undergoing salpingectomy for salpingitis (n = 35) and tubal pregnancy (n = 35). Twenty patients with benign uterine diseases undergoing complete hysterectomy and salpingectomy were recruited into control group. BAFF mRNA and protein in tissue samples were detected by qPCR and Western blotting methods. Furthermore, serum levels of BAFF, tumor necrosis factor-α (TNF-α) and interleukin (IL)-6 were measured using ELISA kits.

Results

We found statistically significantly elevated expressions of BAFF mRNA or protein in whole tissue samples, and serum levels of BAFF, TNF-α and IL-6 in whole blood samples from patients with salpingitis and tubal pregnancy, in comparison to the control group.

Conclusion

Based on the results, high expression of BAFF gene might induce inflammation in the human fallopian tube, suggesting its possible role in the tubal pregnancy process.

Maternal Serum B Cell activating factor in hypertensive and normotensive pregnancies

OBJECTIVES

The objective of this study was the analysis of B-Cell Activating Factor (BAFF) levels in pregnancies affected by PE, and in pregnancies affected by fetal growth restriction without Hypertensive disorders and its possible correlation with pulse wave velocity and cardiac output.

STUDY DESIGN

Prospective study of 69 women at 24-40 weeks gestation. Haemodynamic function was assessed in those with Pre-eclampsia (PE, n = 19), fetal growth restriction (FGR, n = 10) and healthy pregnancies (n = 40). Maternal venous BAFF levels at recruitment were measured using ELISA. We analysed the relationship between BAFF and cardiac output (CO), and BAFF and PWV (pulse wave velocity); the gold standard for assessing arterial stiffness. PWV was measured with an oscillometric device and CO using inert gas rebreathing technique. PWV and CO were converted to gestation adjusted indices (z scores).

MAIN OUTCOME MEASURES

The association between BAFF levels in PE and FGR, and the relationship of BAFF with PWV and CO.

RESULTS

BAFF was higher in PE (p = 0.03) but not in FGR (p = 0.83) when compared to healthy pregnancies. There was a positive correlation between BAFF levels and z score PWV (r = 0.25, p = 0.04), but not CO (r = -0.01, p = 0.91). BAFF levels did not change with gestational age. (r = 0.012, p = 0.925).

CONCLUSIONS

These findings provide evidence of a possible contribution of BAFF to both maternal inflammation and arterial dysfunction associated with PE. Though no relationship was found with another disorder of placentation: normotensive FGR, this condition is not thought to be associated with maternal inflammation.