Serum B-cell activating factor is not a potential biomarker for disease activity in chronic inflammatory demyelinating polyneuropathy.

B-cell activating factor (BAFF) is a crucial cytokine for differentiation and survival of B-cells and correlates to disease activity in some auto-immune diseases. To evaluate BAFF as a biomarker for disease activity in chronic inflammatory demyelinating polyneuropathy (CIDP), serum BAFF levels were measured at varying disease stages: patients starting treatment, patients starting treatment withdrawal, patients in remission and healthy controls. Serum BAFF levels were elevated in patients compared to healthy controls, but did not differ between patients starting treatment and patients in remission. Serum BAFF levels did not change with or predict treatment response or relapse. Serum BAFF is not a responsive biomarker reflecting disease activity in CIDP.

Pre- and Post-treatment Serum BAFF Levels and BAFF Gene Polymorphisms in Patients with Graves' Disease.

BACKGROUND: B cell activating factor (BAFF), a crucial factor for B cell survival and differentiation, has been linked to several autoimmune conditions. The aim of this study was to evaluate the association of BAFF gene's polymorphisms with its serum levels and to assess their effect on Graves' disease (GD) susceptibility and presentation. METHODS: Sixty-two GD patients and 152 healthy controls have been enrolled to investigate BAFF rs9514827 (-2841 T/C), rs1041569 (-2701 T/A) and rs9514828 (-871 C/T) gene's polymorphism by PCR-RFLP and serum BAFF level's kinetics under medical treatment by ELISA. RESULTS: Median serum BAFF level at baseline was significantly higher in GD patients (841.7 pg/ml [685.23-1058.32]) comparatively to controls (495.75 pg/ml [383.17-595.7]), p = 7.29 E-25. A ROC curve was used to assess BAFF performances in GD diagnosis and revealed an AUC of 94.9% [0.919-0.979], p = 7.29 E-25. At a cutoff value of 654.9 pg/ml of BAFF at baseline, the sensitivity and the specificity were, respectively, 83.9% and 90.8%. BAFF level was significantly increased in smoking patients (1079.55 pg/ml [875.35-1203]) comparatively to nonsmokers (746.95 pg/ml [643.2-915.7]), p = 3.1 E-5. While -2841 T/C and -2701 T/A genotypes and alleles frequencies were similar between patients and controls, the -871*T allele was significantly more prevalent in patients (0.613) than in controls (0.477); p = .01, OR [95% CI] = 1.73 [1.13-2.65]. The three studied polymorphisms were not associated with serum BAFF level at baseline. CONCLUSION: Serum BAFF level is significantly increased in GD especially in smoking patients. rs9514828 - 871*T allele might be a susceptibility variant for GD.

B-cell activating factor and A proliferation-inducing ligand in relation to intima-media thickness as biomarkers of premature atherosclerosis in systemic lupus erythematosus patients.

BACKGROUND: The aim of this study was to assess the correlation of the serum B-cell activating factor (BAFF), A proliferation-inducing ligand (APRIL) and interleukin (IL)-21 with carotid intima-media thickness (cIMT) to evaluate their efficacy as non-invasive biomarkers for the risk of premature development of atherosclerosis. METHODS: ELISA test was used to quantify serum BAFF, APRIL and IL-21 in 40 patients with systemic lupus erythematosus (SLE) and 20 healthy controls (HCs). The obtained results were correlated with disease duration, anti-double stranded DNA, complement proteins levels, lipid profile, cIMT and the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). RESULTS: Serum BAFF, APRIL and IL-21 were significantly increased in SLE compared to HCs. Positive correlation was recorded between BAFF (r = 0.51) and APRIL (r = 0.52) with the cIMT. IL-21 correlated positively with SLEDAI (r = 0.33) and negatively with BAFF (r = -0.37) and APRIL (r = -0.44). According to the multiple logistic regression analysis, we found that low-density lipoprotein, serum BAFF and APRIL values were independent factors for cIMT in SLE. To discriminate premature atherosclerosis in patients with SLE, BAFF ≥455 pg/ml yielded 88.9% sensitivity with 100% specificity while APRIL ≥600 pg/ml yielded 95% sensitivity with 100% specificity. IL-21 ≥240 pg/ml yielded 66.7% sensitivity and 100% specificity. CONCLUSIONS: Circulating BAFF and APRIL in patients with SLE were correlated to disease activity and cIMT, suggesting that they could be used as a peripheral blood biomarker for the occurrence of premature atherosclerosis in SLE.

Correlation of Serum Levels of Interleukine-16, CCL27, Tumor Necrosis Factor-related Apoptosis-inducing Ligand, and B-cell Activating Factor with Multiple Sclerosis Severity.

The pathogenic roles of Interleukine-16 (IL-16), CCL27, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and B-cell activating factor (BAFF) has been shown in some autoimmune and inflammatory diseases. We aimed to correlate the circulatory changes of such factors with the severity of disease in patients with multiple sclerosis (MS). This case-control study was conducted on 84 MS patients and 83 healthy controls. We measured the serum levels of IL-16, CCL27, TRAIL, and BAFF in all participants by enzyme-linked immune sorbent assay. Using the expanded disability status scale (EDSS), we evaluated the severity of MS. Finally, we assessed the correlation between serum levels of such factors with the severity of MS. We found increased serum levels of CCL27, IL-16, and BAFF in patients with MS compared to those in healthy subjects. However, no difference was found in serum levels of TRAIL between the patients and controls. In addition, a significant positive correlation between serum levels of CCL27, IL-16, TRAIL, and BAFF with disease severity according to EDSS score was determined. We showed higher serum levels of CCL27, BAFF, TRAIL, and IL-16 in MS patients with more severe disabilities than mild forms. Such finding may represent their contribution to the pathogenesis of MS. Blocking such molecules may yield new treatments for MS.

Circulating BAFF as novel biomarker in distinguishing chronic rhinosinusitis with nasal polyps endotypes and predicting postoperative recurrence.

BACKGROUND: B cell-activating factor (BAFF) is a proinflammatory cytokine involved in inflammatory and allergic diseases, but its role in chronic rhinosinusitis with nasal polyps (CRSwNP) remains unclear. This study aims to explore the predictive value of circulating BAFF in CRSwNP endotypes and postoperative recurrence. METHODS: We recruited 120 CRSwNP patients, including 68 non-eosinophilic CRSwNP (neCRSwNP) patients, 52 eosinophilic CRSwNP (CRSwNP) patients, and 60 healthy controls (HCs). Circulating BAFF levels of all participants were measured by enzyme-linked immunosorbent assay (ELISA), and receiver-operating characteristic (ROC) and logistic regression analyses were applied to assess the predictive ability of BAFF levels in distinguishing CRSwNP endotypes. All CRSwNP patients were followed for more than 3 years, and the predictive value of circulating BAFF for postoperative recurrence was evaluated. RESULTS: Serum BAFF levels were elevated in CRSwNP patients compared with the HCs (P < 0.01) and significantly higher in eCRSwNP patients. The increased serum BAFF concentrations positively correlated with blood eosinophil counts and percentages, tissue eosinophil counts, and serum total IgE (P < 0.05). The ROC curve showed that serum BAFF exhibited strong discriminative ability for eCRSwNP. Finally, 99 CRSwNP patients completed the follow-up schedule, 65 patients were classified into non-recurrence group and the other 34 patients were categorized into recurrence group. Serum BAFF levels were significantly higher in recurrence group than non-recurrence group (P < 0.001), and the ROC curve suggested a high predictive value of serum BAFF in predicting postoperative recurrence. Moreover, logistic regression and Kaplan-Meier curves showed that serum BAFF was an independent risk factor for postoperative recurrence (P < 0.05). CONCLUSION: Our data suggested that serum BAFF levels were upregulated in CRSwNP patients and correlated with mucosal eosinophil infiltration severity. Serum BAFF seemed to be a novel biomarker for preoperatively distinguishing CRSwNP endotypes and predicting postoperative recurrence.

Plasma Levels of the Cytokines B Cell-Activating Factor (BAFF) and A Proliferation-Inducing Ligand (APRIL) in Schizophrenia, Bipolar, and Major Depressive Disorder: A Cross Sectional, Multisite Study.

BACKGROUND: Immune dysfunction has been implicated in the pathogenesis of schizophrenia and other nonaffective psychosis (SCZ), bipolar spectrum disorder (BIP) and major depressive disorder (MDD). The cytokines B cell-activating factor (BAFF) and A proliferation-inducing ligand (APRIL) belong to the tumor necrosis factor (TNF) super family and are essential in orchestrating immune responses. Abnormal levels of BAFF and APRIL have been found in autoimmune diseases with CNS affection. METHODS: We investigated if plasma levels of BAFF and APRIL differed between patients with SCZ, BIP, and MDD with psychotic symptoms (n = 2009) and healthy control subjects (HC, n = 1212), and tested for associations with psychotic symptom load, controlling for sociodemographic status, antipsychotic and other psychotropic medication, smoking, body-mass-index, and high sensitivity CRP. RESULTS: Plasma APRIL level was significantly lower across all patient groups compared to HC (P < .001; Cohen's d = 0.33), and in SCZ compared to HC (P < .001; d = 0.28) and in BIP compared to HC (P < .001; d = 0.37). Lower plasma APRIL was associated with higher psychotic symptom load with nominal significance (P = .017), but not with any other clinical characteristics. Plasma BAFF was not significantly different across patient groups vs HC, but significantly higher in BIP compared to HC (P = .040; d = 0.12) and SCZ (P = .027; d = 0.10). CONCLUSIONS: These results show aberrant levels of BAFF and APRIL and association with psychotic symptoms in patients with SCZ and BIP. This suggest that dysregulation of the TNF system, mediated by BAFF and APRIL, is involved in the pathophysiology of psychotic disorders.

Serum CXCL13, BAFF, IL-21 and IL-22 levels are related to disease activity and lymphocyte profile in primary Sjögren's syndrome.

OBJECTIVES: To investigate the utility of serum BAFF, IL-17, IL-18, IL-21, IL-22, CXCL13, TNF-R2 and PD-L2 as biomarkers of disease activity in primary Sjögren's syndrome (pSS), their relationship with lymphocyte subpopulations and their accuracy to discriminate pSS from Sicca syndrome. METHODS: We conducted an observational study on 66 pSS patients and 48 controls (25 with Sicca syndrome and 23 healthy volunteers). Serum levels of BAFF, IL-17 A/F, IL-18, IL-21, IL-22, CXCL13, TNF-R2 and PD-L2 were measured using a multiplex immunoassay. Lymphocyte subpopulations were analysed by flow cytometry. Disease activity of pSS was assessed with ESSDAI at study inclusion. RESULTS: Patients with pSS presented higher serum CXCL13 (364.7 vs. 205.2 pg/mL), IL-21 (43.2 vs. 0 pg/mL) and BAFF (1646 vs. 1369 pg/mL), and lower PD-L2 levels (1950.8 vs. 2792.3 pg/mL) than controls. ESSDAI was associated with BAFF, IL-18 and IL-22. Patients with ESSDAI >0 exhibited higher CXCL13, IL-21, IL-22 and TNFR2 concentrations. IL-21 levels correlated with lower memory B-cell and higher naïve B-cell percentages and IL-22 levels correlated with increased circulating activated CD4+ T-cells. The combination of serum CXCL13, BAFF and PDL2 levels using the formula [ln(CXCL13)+ln(BAFF)]/ln(PDL2) exhibit an AUC of 0.854 (95% CI: 0.750-0.919) to discriminate between pSS and Sicca syndrome (sensitivity 77.2% and specificity 86.4% using a cut-off of 1.7). CONCLUSIONS: CXCL13, BAFF, IL-21, and IL-22 are potential biomarkers of pSS activity and IL-21 and IL-22 are associated with disturbances of lymphocyte subpopulations in pSS. The combination of serum CXCL13, BAFF, and PD-L2 levels allows discrimination between pSS and Sicca syndrome.

Osteopontin and malaria: no direct effect on parasite growth, but correlation with P. falciparum-specific B cells and BAFF in a malaria endemic area.

BACKGROUND: The dysregulation of B cell activation is prevalent during naturally acquired immunity against malaria. Osteopontin (OPN), a protein produced by various cells including B cells, is a phosphorylated glycoprotein that participates in immune regulation and has been suggested to be involved in the immune response against malaria. Here we studied the longitudinal concentrations of OPN in infants and their mothers living in Uganda, and how OPN concentrations correlated with B cell subsets specific for P. falciparum and B cell activating factor (BAFF). We also investigated the direct effect of OPN on P. falciparum in vitro. RESULTS: The OPN concentration was higher in the infants compared to the mothers, and OPN concentration in infants decreased from birth until 9 months. OPN concentration in infants during 9 months were independent of OPN concentrations in corresponding mothers. OPN concentrations in infants were inversely correlated with total atypical memory B cells (MBCs) as well as P. falciparum-specific atypical MBCs. There was a positive correlation between OPN and BAFF concentrations in both mothers and infants. When OPN was added to P. falciparum cultured in vitro, parasitemia was unaffected regardless of OPN concentration. CONCLUSIONS: The concentrations of OPN in infants were higher and independent of the OPN concentrations in corresponding mothers. In vitro, OPN does not have a direct effect on P. falciparum growth. Our correlation analysis results suggest that OPN could have a role in the B cell immune response and acquisition of natural immunity against malaria.

Possible interplay between estrogen and the BAFF may modify thyroid activity in Graves' disease.

A link between sex hormones and B-cell activating factor (BAFF), a crucial immunoregulator of autoimmune thyroid disease (AITD), may exist. The study aimed to elucidate the role of estrogen (E2) in regulating BAFF in Graves' disease (GD). In clinical samples, serum BAFF levels were higher in women than in men in both the GD and control groups. serum BAFF levels were associated with thyroid-stimulating hormone receptor antibody levels and thyroid function only in women and not in men. BAFF transcripts in peripheral blood mononuclear cells were higher in women with GD than those in the control group. Among GD patients with the AA genotype of rs2893321, women had higher BAFF transcripts and protein levels than men. In the progression of a spontaneous autoimmune thyroiditis (SAT) murine model, NOD.H-2h4, serum free thyroxine and BAFF levels were higher in female than in male mice. Moreover, exogenous E2 treatment increased serum BAFF levels in male SAT mice. Meanwhile, female SAT mice exhibited higher thyroid BAFF transcripts levels than either the E2-treated or untreated male SAT mouse groups. Our results showed that E2 might be implicated in modulating BAFF expression, and support a possible mechanism for the higher incidence of AITD in women.

Fecal Microbiota Transplantation Modulates Renal Phenotype in the Humanized Mouse Model of IgA Nephropathy.

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis. Several observations suggest that gut microbiota could be implicated in IgAN pathophysiology. Aiming at exploring whether microbiota modulation is able to influence disease outcome, we performed fecal microbiota transplantation (FMT) from healthy controls (HC-sbjs), non-progressor (NP-pts) and progressor (P-pts) IgAN patients to antibiotic-treated humanized IgAN mice (α1KI-CD89Tg), by oral gavage. FMT was able to modulate renal phenotype and inflammation. On one hand, the microbiota from P-pts was able to induce an increase of serum BAFF and galactose deficient-IgA1 levels and a decrease of CD89 cell surface expression on blood CD11b+ cells which was associated with soluble CD89 and IgA1 mesangial deposits. On the other hand, the microbiota from HC-sbjs was able to induce a reduction of albuminuria immediately after gavage, an increased cell surface expression of CD89 on blood CD11b+ cells and a decreased expression of KC chemokine in kidney. Higher serum BAFF levels were found in mice subjected to FMT from IgAN patients. The main bacterial phyla composition and volatile organic compounds profile significantly differed in mouse gut microbiota. Microbiota modulation by FMT influences IgAN phenotype opening new avenues for therapeutic approaches in IgAN.

B-cell activating factor BAFF as a novel alert marker for the immunological risk stratification after kidney transplantation.

The B cell activating factor BAFF has gained importance in the context of kidney transplantation due to its role in B cell survival. Studies have shown that BAFF correlates with an increased incidence of antibody-mediated rejection and the development of donor-specific antibodies. In this study, we analyzed a defined cohort of kidney transplant recipients who were treated with standardized immunosuppressive regimens according to their immunological risk profile. The aim was to add BAFF as an awareness marker in the course after transplantation to consider patient's individual immunological risk profile. Included patients were transplanted between 2016 and 2018. Baseline data, graft function, the occurrence of rejection episodes, signs of microvascular infiltration, and DSA kinetics were recorded over 3 years. BAFF levels were determined 14 d, 3 and 12 months post transplantation. Although no difference in graft function could be observed, medium-risk patients showed a clear dynamic in their BAFF levels with low levels shortly after transplantation and an increase in values of 123% over the course of 1 year. Patients with high BAFF values were more susceptible to rejection, especially antibody-mediated rejection and displayed intensified microvascular inflammation; the combination of high BAFF + DSA puts patients at risk. The changing BAFF kinetics of the medium risk group as well as the increased occurrence of rejections at high BAFF values enables BAFF to be seen as an awareness factor. To compensate the changing immunological risk, a switch from a weaker induction therapy to an intensified maintenance therapy is required.

Expansion of inflammatory monocytes in periphery and infiltrated into thyroid tissue in Graves' disease.

Monocytes are important mediators of immune system and are reported to be altered in autoimmune disorders. Little is known about the pathological role of monocytes in Graves' disease (GD). Thus, we investigated monocytes in periphery and thyroid tissue in GD. Untreated GD patients were enrolled and followed up until remission. Monocytes were significantly increased and positively correlated with anti-thyrotropin receptor antibody (TRAb) in untreated GD (rcounts = 0.269, P < 0.001; rpercentage = 0.338, P < 0.001). Flow cytometry showed CD14++ CD16+ monocytes were increased and CD14++ CD16- monocytes were decreased in untreated GD (both P < 0.001). Skewed monocyte subsets were recovered in GD with remission. Serum B cell-activating factor (BAFF) was positively correlated with TRAb (r = 0.384 and P = 0.001). CD14++ CD16+ monocytes expressed higher level of BAFF in untreated GD (P < 0.05). The frequency of CD14+ monocytes and CD14+ CD16+ monocytes were significantly higher in GD thyroid tissue than in normal thyroid tissue (both P < 0.001). Our study suggested CD14++ CD16+ monocytes were significantly expanded and involved in the production of TRAb via secreting a higher level of BAFF in periphery. Besides, monocytes infiltrated into thyroid tissue and thus could serve as an important participant in GD pathogenesis.

Extensive serum biomarker analysis in the prethrombotic state of recurrent spontaneous abortion.

The prethrombotic state (PTS) is a possible cause of recurrent spontaneous abortion (RSA). The aim of this study was to identify serum biomarkers for the detection of RSA with PTS (PSRSA). A Quantibody array 440 was used to screen novel serum-based biomarkers for PSRSA/NRSA (RSA without PTS). Proteins differentially expressed in PSRSA were analysed using bioinformatics methods and subjected to a customized array and enzyme-linked immunosorbent assay (ELISA) validation. We used receiver operating characteristic to calculate diagnostic accuracy, and machine learning methods to establish a biomarker model for evaluation of the identified targets. 20 targets were selected for validation using a customized array, and seven targets via ELISA. The decision tree model showed that IL-24 was the first node and eotaxin-3 was the second node distinguishing the PSRSA and NRSA groups (an accuracy rate of 100% and an AUC of 1). Epidermal growth factor (EGF) as the node distinguished the PSRSA and NC groups (an accuracy rate of 100% and an AUC of 1). EGF as the node distinguished the NRSA and NC groups (an accuracy rate of 96.5% and an AUC of 0.998). Serum DNAM-1, BAFF, CNTF, LAG-3, IL-24, Eotaxin-3 and EGF represent a panel of promising diagnostic biomarkers to detect the PSRSA.

Modifications of the BAFF/BAFF-Receptor Axis in Patients With Pemphigus Treated With Rituximab Versus Standard Corticosteroid Regimen.

The efficacy of the B-cell-depleting agent rituximab has been reported in immune diseases but relapses are frequent, suggesting the need for repeated infusions. The B-cell activating factor (BAFF) is an important factor for B cell survival, class switch recombination and selection of autoreactive B cells, as well as maintaining long-lived plasma cells. It has been hypothesized that relapses after rituximab might be due to the increase of serum BAFF levels. From the Ritux3 trial, we showed that baseline serum BAFF levels were higher in pemphigus patients than in healthy donors (308 ± 13 pg/mL versus 252 ± 28 pg/mL, p=0.037) and in patients with early relapse compared who didn't (368 ± 92 vs 297 ± 118 pg/mL, p=0.036). Rituximab and high doses of CS alone have different effects on the BAFF/BAFF-R axis. Rituximab led to an increase of BAFF levels associated to a decreased mRNA (Day 0: 12.3 ± 7.6 AU vs Month 36: 3.3 ± 4.3 AU, p=0.01) and mean fluorescence intensity of BAFF-R in non-autoreactive (Day 0: 3232 vs Month 36: 1527, mean difference: 1705, 95%CI: 624 to 2786; p=0.002) as well as on reappearing autoreactive DSG-specific B cells (Day 0: 3873 vs Month 36: 2688, mean difference: 1185, 95%CI: -380 to 2750; p=0.20). Starting high doses of corticosteroids allowed a transitory decrease of serum BAFF levels that re-increased after doses tapering whereas it did not modify BAFF-R expression in autoreactive and non-autoreactive B cells. Our results suggest that the activation of autoreactive B cells at the onset of pemphigus is likely to be related to the presence of high BAFF serum levels and that the decreased BAFF-R expression after rituximab might be responsible for the delayed generation of memory B cells, resulting in a rather long period of mild pemphigus activity after rituximab therapy. Conversely, the incomplete B cell depletion and persistent BAFF-R expression associated with high BAFF serum levels might explain the high number of relapses in patients treated with CS alone.

The role of BAFF and G-CSF for rituximab-induced late-onset neutropenia (LON) in lymphomas.

Mechanisms for late-onset neutropenia (LON) after rituximab treatment are poorly defined both for non-Hodgkin lymphoma (NHL) and for autoimmune disorders. We performed a case-control analysis of a prospective cohort of 169 evaluable consecutive rituximab-treated NHL patients to assess cytokines involved in neutro- and lymphopoiesis (G-CSF, SDF1, BAFF, APRIL) and inflammation (CRP) as possible LON mechanisms. Fifteen patients (9%) developed LON (peripheral blood /PB/ absolute neutrophil counts /ANC/ < 0.5 G/L, all with marked depletion of CD20+ B-lymphocytes in bone marrows); they were compared with 20 matched NHL controls without LON. At start of LON, significantly higher PB G-CSF and BAFF levels (P = 0.0004 and 0.006, respectively), as well as CRP rises were noted compared to controls; these G-CSF and BAFF and most CRP values returned to levels of the controls in post-LON samples. G-CSF (but not BAFF) changes correlated to CRP rises (but not to ANC levels). BAFF levels correlated significantly to absolute monocyte counts and PB large granular lymphocyte counts (but not to ANC, C-CSF or CRP values). No changes of SDF1 or APRIL levels were noted. Neither LON cases nor controls displayed anti-neutrophil autoantibodies. Collectively, LON in NHL patients was timewise related to transient bursts of blood G-CSF and BAFF concentrations, suggesting that these neutro- and lymphopoiesis growth factors play a role in emergence of rituximab-induced LON, and that inflammation may be a trigger for G-CSF production during LON.

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.

Cerebrospinal fluid and serum protein markers in autism: A co-twin study.

No robust biomarkers have yet been identified for autism spectrum disorder (ASD) or autistic traits. Familial factors likely influence biomarkers such as protein concentrations. Comparing twins with ASD or high autistic traits to the less affected co-twin allows estimating the impact of familial confounding. We measured 203 proteins in cerebrospinal fluid (n = 86) and serum (n = 127) in twins (mean age 14.2 years, 44.9% females) enriched for ASD and other neurodevelopmental conditions. Autistic traits were assessed by using the parent-report version of the Social Responsiveness Scale-2. In cerebrospinal fluid, autistic traits correlated negatively with three proteins and positively with one. In serum, autistic traits correlated positively with 15 and negatively with one. Also in serum, six were positively-and one negatively-associated with ASD. A pathway analysis of these proteins revealed immune system enrichment. In within twin pair analyses, autistic traits were associated with serum B-cell activating factor (BAFF) only, whereas Cystatin B (CSTB) remained significantly associated with ASD. These associations did not remain significant when only considering monozygotic twins. For the remainder, the within-pair analysis indicated familial confounding, including shared environment and genes, influencing both autism and protein levels. Our findings indicate proteins involved in immunity as putative biomarkers of autistic traits and ASD with partial genetic confounding. Although some results are in line with previous studies in general, further studies are needed for replication.

Serum markers of B-cell activation in pregnant women with atopic asthma.

PROBLEM: As maternal atopy represents a risk factor for the development of atopy in offspring, we aimed to assess how pregnancy affects B-cell activation markers in women with atopic asthma and whether they correlate with risk manifestations for allergy in newborns from mothers with atopic asthma. METHOD OF STUDY: Pregnant women with atopic asthma (AP) in the third trimester of gestation and nonpregnant women with atopic asthma (ANP) were prospectively recruited and compared to respective healthy counterparts (HP and HNP). All pregnant women were also assessed during the postpartum period until 6 weeks after delivery (HP/PP and AP/PP). Newborns were clinically evaluated at the age of 6 months. Peripheral blood samples were taken from each woman at each time point. Soluble CD23 (sCD23), B-cell activating factor (BAFF), IgA, IgG, IgM, kappa (κ), and lambda (λ) free light chains (FLC) were quantified in serum samples. RESULTS: The AP group presented increased sCD23 (p < 0.05) and BAFF (p < 0.001) levels compared to the ANP group and even higher levels of sCD23 during the postpartum period (p < 0.001). Moreover, the cutoffs of 6.74 g/L for IgG (sensitivity 90.9%, specificity 77.8%) and of 11.30 mg/L for λ FLC (sensitivity 81.8%, specificity 88.9%) in the AP group were predictive factors for the manifestation of allergy in their offspring. CONCLUSIONS: After delivery, the dynamics of sCD23 and BAFF changed significantly in the AP group. Furthermore, we found novel predictive factors for allergy manifestations in the children of these women, with potential clinical application.

A longitudinal study of plasma BAFF levels in mothers and their infants in Uganda, and correlations with subsets of B cells.

Malaria is a potentially life-threatening disease with approximately half of the world's population at risk. Young children and pregnant women are hit hardest by the disease. B cells and antibodies are part of an adaptive immune response protecting individuals continuously exposed to the parasite. An infection with Plasmodium falciparum can cause dysregulation of B cell homeostasis, while antibodies are known to be key in controlling symptoms and parasitemia. BAFF is an instrumental cytokine for the development and maintenance of B cells. Pregnancy alters the immune status and renders previously clinically immune women at risk of severe malaria, potentially due to altered B cell responses associated with changes in BAFF levels. In this prospective study, we investigated the levels of BAFF in a malaria-endemic area in mothers and their infants from birth up to 9 months. We found that BAFF-levels are significantly higher in infants than in mothers. BAFF is highest in cord blood and then drops rapidly, but remains significantly higher in infants compared to mothers even at 9 months of age. We further correlated BAFF levels to P. falciparum-specific antibody levels and B cell frequencies and found a negative correlation between BAFF and both P. falciparum-specific and total proportions of IgG+ memory B cells, as well as CD27- memory B cells, indicating that exposure to both malaria and other diseases affect the development of B-cell memory and that BAFF plays a part in this. In conclusion, we have provided new information on how natural immunity against malaria is formed.

BAFF serum and CSF levels in patients with multiple sclerosis and infectious nervous system diseases.

PURPOSE: Multiple sclerosis (MS) is the most common immune-mediated CNS disease, characterised by demyelination and progressive neurological disability. The B-cell activating factor BAFF has been described as one important factor in the pathophysiology of different autoimmune diseases. METHODS: We measured BAFF levels in the serum and cerebrospinal fluid (CSF) in 50 consecutive patients with MS and 35 patients with infectious CNS disease (ID). 52 patients with other, non-inflammatory disorders (OND), served as controls. RESULTS: BAFF-serum levels in ID patients were higher than in patients diagnosed with MS (ID 0.55 ± 0.24 ng/ml, MS 0.43 ± 0.14 ng/ml, OND 0.45 ± 0.24 ng/ml; p = 0.09). Interestingly, MS patients had lower BAFF CSF levels compared to the controls and ID patients, and the CSF levels in the latter were elevated compared to those of the controls (MS 0.17 ± 0.11 ng/ml, OND 0.25 ± 0.14 ng/ml, ID 0.97 ± 0.78 ng/ml; p < 0.001). CONCLUSIONS: The ID patients' having higher absolute BAFF levels in the CSF than in the serum indicates that the increased BAFF CSF levels were caused by intrathecal synthesis rather than passive transfer via a disturbed blood-brain-barrier. The significantly decreased BAFF CSF levels in MS patients were a surprising result of our study. Although it has been reported that astrocytes in active MS lesions can express BAFF, the soluble form was not increased in the CSF of MS patients. It remains unclear whether the inflammatory features of active MS plaques are truly represented by the CSF compartment.