Serum A Proliferation-inducing Ligand Levels Research Articles

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

BackgroundGestational 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 methodsIn 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. ResultsIn 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 conclusionThis 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.

The role of BAFF and APRIL in IgA nephropathy: pathogenic mechanisms and targeted therapies.

Immunoglobulin A nephropathy (IgAN), characterized by mesangial deposition of galactose-deficient-IgA1 (Gd-IgA1), is the most common biopsy-proven primary glomerulonephritis worldwide. Recently, an improved understanding of its underlying pathogenesis and the substantial risk of progression to kidney failure has emerged. The "four-hit hypothesis" of IgAN pathogenesis outlines a process that begins with elevated circulating levels of Gd-IgA1 that trigger autoantibody production. This results in the formation and deposition of immune complexes in the mesangium, leading to inflammation and kidney injury. Key mediators of the production of Gd-IgA1 and its corresponding autoantibodies are B-cell activating factor (BAFF), and A proliferation-inducing ligand (APRIL), each playing essential roles in the survival and maintenance of B cells and humoral immunity. Elevated serum levels of both BAFF and APRIL are observed in patients with IgAN and correlate with disease severity. This review explores the complex pathogenesis of IgAN, highlighting the pivotal roles of BAFF and APRIL in the interplay between mucosal hyper-responsiveness, B-cell activation, and the consequent overproduction of Gd-IgA1 and its autoantibodies that are key features in this disease. Finally, the potential therapeutic benefits of inhibiting BAFF and APRIL in IgAN, and a summary of recent clinical trial data, will be discussed.

Abnormal immune function of B lymphocyte in peripheral blood of Parkinson's disease

BackgroundParkinson's disease (PD) is associated with peripheral inflammation and abnormal peripheral blood lymphocyte immune responses. Peripheral blood B-lymphocyte subset distributions and whether they are associated with PD are unclear. MethodsSixty-one PD patients and sixty-one one-to-one paired healthy controls (HCs) were enrolled. We used flow cytometry to perform immunophenotyping of peripheral B-lymphocyte, in vitro stimulation and measured serum cytokine. The relationship between variables and PD were assessed. ResultsThe percentage of naive B cells in blood of PD patients was decreased, whereas the percentages of regulatory B cells (Bregs), plasma blast cells (PBCs), and double-negative (DN) B cells were increased. The absolute counts of B-lymphocyte and naive B cells in blood of PD patients were decreased. Regression analysis revealed that alterations in the absolute counts of B-lymphocyte and the percentage of Bregs and DN B cells were associated with PD. After stimulation, the percentages of Bregs, PBCs, and switched memory (SwM) B cells increased in PD patients. Additionally, increases in GM-CSF-producing B-cell, IFN-γ-producing B-cell, and TNF-α-producing B-cell percentages were noted in PD. Serum levels of a proliferation-inducing ligand (APRIL), B-cell activating factor (BAFF) and soluble CD40 ligand (sCD40L) were elevated in PD and correlated negatively with the UPDRS III score. ConclusionsAbnormal B-lymphocyte immune responses in peripheral blood may contribute to PD development. Alterations in the absolute counts of B-lymphocyte and the percentage of Bregs and DN B cells are associated with PD. Furthermore, APRIL, BAFF, and sCD40L could be potential targets for intervention in PD.

#4337 UPDATED INTERIM RESULTS OF A PHASE 1/2 STUDY OF BION-1301 IN PATIENTS WITH IGA NEPHROPATHY

Abstract Background and Aims Immunoglobulin A nephropathy (IgAN) is the leading cause of primary glomerulonephritis worldwide with limited treatment options, especially for high-risk patients. Approximately 30-45% of IgAN patients progress to end-stage kidney disease over a period of 20-25 years and proteinuria is the strongest predictor of disease progression [1]. BION-1301 is a novel humanized monoclonal antibody that blocks a proliferation-inducing ligand (APRIL), a cytokine that is elevated in patients with IgAN. APRIL promotes the production of pathogenic galactose-deficient IgA1 (Gd-IgA1), leading to immune complex deposition and subsequent kidney injury. Blocking APRIL with BION-1301 is a potential disease-modifying approach to directly target the pathogenesis of IgAN. In a Phase 1/2 study (NCT 03945318) in healthy volunteers and patients with IgAN, BION-1301 was well-tolerated with no serious adverse events (SAEs) and durably reduced free APRIL, IgA, Gd-IgA1, IgM and to a lesser extent, IgG [2]. Method For the ongoing phase 1/2 open-label, multicohort trial, eligibility criteria include adults with biopsy-proven IgAN, eGFR ≥30 mL/min per 1.73 m2, baseline urine protein excretion ≥0.5 g/24 hrs or UPCR ≥0.5 g/g, and on stable/optimized RASi (or intolerant). Cohort 1 received 450 mg of BION-1301 administered IV every 2 weeks, transitioning to SC at 600 mg every 2 weeks after at least 24 weeks. Cohort 2 receives 600 mg of BION-1301 SC every 2 weeks. Results In both Cohorts 1 and 2, BION-1301 was generally well-tolerated, with no SAEs or terminations due to AEs as of the last reported interim analysis (November 2022) [2]. Durable reductions in serum levels of free APRIL and immunoglobulins were observed in both cohorts. No anti-drug antibodies have been observed in patients with IgAN to date. In Cohort 1, clinically meaningful reductions in proteinuria were seen as early as 12 weeks (30.4% geometric mean UPCR reduction, n = 7), and were sustained through 24 weeks (48.8% geometric mean UPCR reduction, n = 8) and 52 weeks (66.9% geometric mean UPCR reduction, n = 8). Reductions in proteinuria were consistent in Cohort 2 (53.8% geometric mean UPCR reduction, n = 9) at 24 weeks. Significant and durable reductions in serum Gd-IgA1 concentrations were observed and were consistent across both cohorts. Updated data will be reported at the time of presentation. Conclusion BION-1301 offers disease-modifying potential by directly targeting the initiating pathogenesis of IgAN. Interim biomarker and clinical activity responses support advancement of BION-1301 into later-stage development for patients with IgAN.

Features of BAFF and APRIL receptors on circulating B cells in antineutrophil cytoplasmic antibody-associated vasculitis.

To investigate the features of circulating B cells, their expressing receptors, serum levels of B-cell activation factor of the TNF family (BAFF), and a proliferation-inducing ligand (APRIL) in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Blood samples from 24 patients with active AAV (a-AAV), 13 with inactive AAV (i-AAV), and 19 healthy controls (HC) were included in this study. The proportion of B cells and their expressing BAFF receptor (BAFF-R), transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), and B-cell maturation antigen were analyzed via flow cytometry. Serum levels of BAFF, APRIL, and interleukin (IL)-4, IL-6, IL-10, and IL-13 were also evaluated using an enzyme-linked immunosorbent assay. The proportion of plasmablasts (PB)/plasma cells (PC) and serum levels of BAFF, APRIL, IL-4, and IL-6 were significantly higher in a-AAV than in HC. Higher serum levels of BAFF, APRIL, and IL-4 were observed in i-AAV than in HC. Lower expression of BAFF-R on memory B cells and higher expression of TACI on CD19+ cells, immature B cells, and PB/PC were demonstrated in a-AAV and i-AAV than in HC. The population of memory B cells was positively associated with serum APRIL levels and BAFF-R expression in a-AAV. In conclusion, decreased expression of BAFF-R on memory B cells and increased expression of TACI on CD19+ cells, immature B cells, and PB/PC, as well as increased serum levels of BAFF and APRIL, were sustained even in the remission phase of AAV. Persistent aberrant signaling of BAFF/APRIL may contribute to disease relapse.

The relationship between serum A proliferation-inducing ligand and B-cell activating factor levels with disease activity and organ involvement in systemic lupus erythematosus.

We aim to investigate the association between serum B-cell activating factor (BAFF) and A proliferation-inducing ligand (APRIL) levels with disease activity and clinical findings in SLE patients. Seventy-nine patients with SLE and 27 healthy controls were included into the study. Serum BAFF and APRIL levels were measured by using ELISA. In 19 patients with active disease at the time of the assessment, BAFF/APRIL levels were reassessed after 6months of follow-up and disease activity was evaluated by using SLEDAI-2K. The relationship between renal histopathology index scores and lupus nephritis (LN) classes with serum BAFF/APRIL levels was examined in 16 patients who had recent renal involvement and underwent biopsy during the study. Although both BAFF/APRIL levels were higher in patients with SLE compared to the control group (p < 0.001), no correlation was found between BAFF/APRIL levels and SLEDAI scores. Serum BAFF levels were higher in patients with renal disease activity (p = 0.01), and there was a significant correlation between APRIL levels and proteinuria (r = 0.42, p = 0.02). A weak inverse correlation was observed between BAFF and C3 levels (r = 0.25, p = 0.02). No correlation was found between BAFF/APRIL levels and renal SLEDAI scores, renal histopathology, activity, and chronicity index scores. In the active disease group after treatment, there was no significant change in serum BAFF levels, but a significant increase in serum APRIL levels was observed. These results suggest that both cytokines are involved in the pathogenesis of SLE and that serum BAFF can be valuable as a biomarker in SLE especially in patients with renal activity.

FC 040INTERIM RESULTS OF PHASE 1 AND 2 TRIALS TO INVESTIGATE THE SAFETY, TOLERABILITY, PHARMACOKINETICS, PHARMACODYNAMICS, AND CLINICAL ACTIVITY OF BION-1301 IN PATIENTS WITH IGA NEPHROPATHY

Abstract Background and Aims IgA nephropathy (IgAN), the leading cause of primary glomerulonephritis, is an autoimmune disease with no approved treatments.1 Progression to end-stage-renal disease occurs in up to 45% of IgAN patients, requiring dialysis or kidney transplant to manage.2-4 A critical step in IgAN pathogenesis is the production of galactose-deficient IgA1 (Gd-IgA1) leading to the generation of anti-Gd-IgA1 autoantibodies and the formation of immune complexes that result in kidney inflammation and damage.5 A Proliferation-Inducing Ligand (APRIL), a soluble factor that regulates B cell differentiation, proliferation and survival of plasma cells, and IgA class-switching is elevated in patients with IgAN6, 7. IgAN patients with high plasma APRIL levels are reported as having higher levels of Gd-IgA1 and proteinuria and lower estimated glomerular filtration rates compared to those with lower plasma APRIL levels.7 BION-1301 is a novel humanized blocking antibody targeting APRIL that has been evaluated in a Phase 1 study of healthy volunteers (HV). In Parts 1 and 2 of the Phase 1 study in HV, we previously reported that BION-1301 was well-tolerated with no serious adverse events (SAEs), a pharmacokinetic (PK) half life &amp;gt;30 days and demonstrated dose-dependent pharmacodynamic (PD) effects characterized by durable reductions in serum levels of free April (fAPRIL), IgA and Gd-IgA1, IgM, and to a lesser extent IgG8. Here we present interim results from Part 3 of the Phase 1 and the Phase 2 Open-Label Extension (OLE) trials that characterize the safety, PK and PD profile, and preliminary efficacy of BION-1301 in patients with IgAN. Method The Phase 1 study (NCT03945318) comprises 3 parts. Parts 1 and 2 assessed single- and multiple ascending doses of BION-1301 in HV from 10mg to 1350mg and 50mg to 450mg once every 2 weeks for one month, respectively. Part 3 is an ongoing, open-label, two cohort design in approximately 20 IgAN patients with BION-1301 at a starting dose and regimen of 450mg once every 2 weeks for a total of 3 months. Key eligibility criteria for Part 3 include: (1) urine protein ≥0.5 g/24h or baseline UPCR ≥0.5 g/g, (2) stable/optimized dose of ACE-I/ARB or be intolerant to ACE-I/ARB, and (3) biopsy-verified diagnosis of IgAN within the past 10 years. Patients completing Part 3 are eligible to enroll in the Phase 2 OLE study (NCT04684745) to receive BION-1301 for up to an additional 2 years. To evaluate PK and PD effects of BION-1301, serum levels of BION-1301, free APRIL (fAPRIL), anti-drug antibodies (ADA), neutralizing antibodies (NAbs), and Gd-IgA1 were quantitated using ELISA-based immunoassays. Serum levels of IgA, IgG, and IgM were measured by immunoturbidimetry. UPCR was assessed from 24-hour urine collections. Results In Part 3 of Phase 1 and the Phase 2 OLE trial to date, BION-1301 has been well tolerated in IgAN patients receiving a 450mg dose every two weeks for 12+ weeks with no SAEs observed. Consistent with PD responses previously reported in HVs, durable reductions in serum levels of fAPRIL and immunoglobulins were also observed in IgAN patients. Clinically meaningful reductions in proteinuria were observed as early as 12 weeks and were associated with the reduction in IgA. Additional data from patients receiving long-term treatment will be updated. Conclusion BION-1301 is a novel humanized anti-APRIL monoclonal antibody being developed as a potential treatment for patients with IgAN. BION-1301 offers disease modifying potential by directly targeting the underlying multi-hit immune pathogenesis of IgAN, which is not addressed with the current standard of care treatment. Promising early biomarker and clinical activity responses support the continued development of BION-1301 in IgAN.

MO258SAFETY, TOLERABILITY, PHARMACOKINETICS AND PHARMACODYNAMICS OF VIS649, AN APRIL-NEUTRALIZING IGG2 MONOCLONAL ANTIBODY, IN HEALTHY VOLUNTEERS: PHASE 1, RANDOMIZED, DOUBLE-BLIND, PLACEBO-CONTROLLED, SINGLE ASCENDING DOSE STUDY

Abstract Background and Aims Immunoglobulin A (IgA) nephropathy (IgAN) is a glomerulonephritis characterized by the presence of circulating and glomerular immune complexes containing galactose-deficient (Gd) IgA1. A proliferation-inducing ligand (APRIL), a member of the tumor necrosis factor superfamily of ligands, is thought to play a key role in the pathogenesis of IgAN by virtue of its role in class-switching to IgA production. VIS649, a humanized immunoglobulin G (IgG2) monoclonal antibody that binds to and blocks the biological actions of APRIL, is in clinical development as a potential treatment for IgAN. The primary objective of this first-in-human study was to evaluate the safety and tolerability of VIS649 in healthy volunteers. Secondary objectives included characterization of the pharmacokinetics (PK) and pharmacodynamics (PD) of VIS649. Method This was a Phase 1, randomized, double-blind, placebo-controlled, single ascending dose study of VIS649 in healthy adult male and female volunteers (ClinicalTrials.gov identifier: NCT03719443). The study was conducted in sequential dosing cohorts. The first four cohorts (0.5, 2.0, 6.0, and 12.0 mg/kg, respectively) each enrolled 9 participants (4 of Japanese descent and 5 of non-Japanese descent) who were randomized to VIS649 or placebo in a ratio of 7:2. In addition, a fifth cohort enrolled 15 adults randomized to receive VIS649 6.0 mg/kg or placebo (10:5), followed by tetanus/diphtheria vaccine challenge after 28 days (TENIVAC®, Sanofi Pasteur Limited; the effect of APRIL inhibition on vaccine response is described in a companion abstract). Participants received intravenous administration of study drug on Day 1, were discharged from the institution on Day 2, and were followed for 16–24 weeks on an outpatient basis. Standard safety assessments and blood sampling for PK and PD were performed at regular intervals. Results 51 participants were randomized and dosed with study drug, of whom 47 (92.2%) completed the study. VIS649 was well tolerated, with no serious adverse events (AEs) or AEs that led to study discontinuation. Most treatment-emergent AEs (TEAEs) were mild; the incidence and severity of TEAEs were not dose dependent. One participant in the 2.0 mg/kg group experienced a severe TEAE of syncope following phlebotomy that the investigator considered unlikely to be related to study drug. There was no clinically relevant effect of treatment on laboratory tests, vital signs, electrocardiogram parameters, or physical examinations. VIS649 had non-linear PK: half-life (t½) increased with dose, while drug exposure (AUC) increased in a greater than dose proportional manner. Serum IgA, Gd-IgA1, IgG, and IgM were reversibly suppressed in a dose-dependent manner following VIS649 administration. The maximum mean percentage reductions from baseline occurred at Week 12 for the 12.0 mg/kg dose: IgA, -57.2% (Figure); Gd-IgA1, -71.6% (Figure); IgG, -33.6%; and IgM, -67.2%. These reductions were reversible and showed a dose-response effect with respect to time-to-recovery. Mean free (non-VIS649 bound) serum APRIL levels decreased to the lower limit of quantification (50 pg/mL) for all VIS649 doses at Week 1, and also showed a dose-response effect with respect to time-to-recovery. No depletions in circulating lymphocyte populations were observed. There were no significant PK or PD differences between Japanese and non-Japanese participants. Conclusion A single dose of VIS649, up to 12.0 mg/kg, was safe and well tolerated in healthy adults and was able to suppress free serum APRIL to the lower level of quantification. Serum Gd-IgA1 decreased in parallel with total serum IgA and recovered in a dose-dependent manner following reappearance of free APRIL in serum. These data support the further clinical development of VIS649 as a potential treatment for IgAN.

MO272CLINICOPATHOLOGICAL CORRELATION OF APRIL AND BAFF IN IG A NEPHROPATHY- A SINGLE CENTER LONGITUDINAL OBSERVATIONAL STUDY

Abstract Background and Aims Aberrantly glycosylated IgA1 molecules are important in the pathogenesis of IgA nephropathy. A proliferation-inducing ligand (APRIL) and B-cell activating factor (BAFF) are cytokines involved in immunoglobulin class switching and production of galactose deficient IgA1(Gd IgA1). We aimed to study the association of serum levels of APRIL and BAFF with the clinical severity and pathological grading of IgA nephropathy (IgAN) and to assess the strength of the association by studying the clinicopathological correlation. Method The research study was conducted as a single-center longitudinal observational study. The study subjects were recruited based on the pathological diagnosis of primary IgA nephropathy. The plasma levels of APRIL, BAFF and Gd IgA1 were estimated using enzyme-linked immunosorbent assay (ELISA). All the study subjects were followed up for one year to study the renal outcome. Results In our study group of thirty-eight patients, the median estimated glomerular filtration rate(eGFR) was 33.9(15.9,79.4) ml/minute/1.73m2. The median levels of the cytokines APRIL and BAFF were 170.81(82.45, 550.61) ng/L and 6.66(3.39,16.33) ng/ml respectively. The baseline characteristics of the study group is given in table 1. APRIL levels had significant positive correlation with Gd IgA1 levels (correlation coefficient 0.556, p=0.003) in patients with IgAN. We also observed that patients with elevated APRIL levels had elevated BAFF levels also (correlation coefficient 0.657, p &amp;lt;0.001). Patients who had crescents, mesangial hypercellularity and endocapillary proliferation in biopsy had elevated APRIL and BAFF levels whereas patients with segmental sclerosis and tubular atrophy had low levels of APRIL(Table 2). However, the levels of APRIL and BAFF did not show any significant correlation with eGFR and proteinuria at time of presentation. At the end of one year, 12(31.5%) patients reached end stage renal disease (ESRD) and these patients had lower levels of APRIL, BAFF, and Gd IgA1. It was also seen that eighty-three percent of those who reached ESRD had chronic changes in biopsy like tubular atrophy and interstitial fibrosis(p=0.05). Hence the severity of tubulointerstitial fibrosis in histology correlated well with progression to end stage renal disease as seen in most glomerular diseases. But we did not find any association between APRIL, BAFF, and Gd IgA1 levels and the decline in eGFR over one year. Conclusion We conclude that levels of APRIL and BAFF are associated with elevated levels of Gd IgA1 in patients with IgAN and had a significant association with proliferative lesions in renal biopsy. But these cytokines levels did not have any association with the eGFR at time of presentation nor decline in eGFR over one year.

POS-144 A PHASE 1, OPEN-LABEL, RANDOMIZED, SINGLE-DOSE, PARALLEL GROUP SAFETY AND BIOAVAILABILITY STUDY OF BION-1301 ADMINISTERED BY INTRAVENOUS (IV) AND SUBCUTANEOUS (SC) ROUTES

IgAN (IgA nephropathy) is the most common primary glomerulonephritis in the world. There are currently no approved treatments and limited off-label treatment options consist largely of supportive measures which do not directly address the underlying immunologic pathogenesis of disease. APRIL (A proliferation-inducing ligand) is critical for IgA class switching, maturation and survival of IgA secreting plasma cells, and production of gd-IgA1 (galactose—deficient IgA1) which is recognized as an auto-antigen leading to the formation of pathogenic IgA immune complexes. BION-1301 is a novel humanized monoclonal antibody that neutralizes APRIL and is currently in Phase 1 development in healthy volunteers and patients with IgAN. In prior Phase 1 studies, BION-1301 was well-tolerated in healthy volunteers and reduced serum levels of free APRIL, IgA, IgM, and to a lesser extent IgG at single doses up to 1350 mg IV and multiple doses up to 450 mg IV every 2 weeks. This study compares pharmacokinetic (PK) and pharmacodynamic (PD) profiles following the administration of BION-1301 300 mg by IV and SC routes in healthy volunteers. Up to 34 healthy volunteers were randomized 1:1 to receive BION-1301 300mg either by IV or SC administration. The primary endpoint was an estimate of the bioavailability of BION-1301 with secondary endpoints of safety, tolerability, PK, PD, and immunogenicity. Subjects were closely monitored during the in-clinic stay through day 8, with in-clinic follow-up visits occurring through the end of study at day 57. PK, PD, and immunogenicity samples were collected periodically throughout the course of the study. BION-1301 continues to be well tolerated with no Grade 3 treatment emergent adverse events or serious adverse event to date. Serum PK profiles; PD profiles including free APRIL, IgA, IgG, and IgM levels; and anti-drug antibody levels will be presented and compared between IV and SC routes. Blockade of APRIL by BION-1301 remains a promising therapeutic approach for the treatment of IgAN. PK and PD data comparing IV and SC administration of BION-1301 will be used to refine the SC dose selection for future global clinical studies of BION-1301 in IgAN.

B cell\u2010activating factors in autoimmune pulmonary alveolar proteinosis

BackgroundAutoimmune pulmonary alveolar proteinosis (APAP) results from the suppression of granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling by a neutralizing autoantibody against GM-CSF. B cell-activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are involved in immunoglobulin G production and are overproduced in various autoimmune disorders. We hypothesized that BAFF and/or APRIL levels would be elevated in serum and bronchoalveolar lavage fluid (BALF) and serum and BALF levels of BAFF and APRIL respond to the treatments (whole lung lavage (WLL) or inhalation of recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF)) in patients with APAP.Subjects and methods BAFF and APRIL levels in serum and BALF from 110 patients with APAP were measured at baseline and during and after treatment, using an enzyme-linked immunosorbent assay kit. We enrolled 34 healthy volunteers as serum cytokine controls, and 13 disease controls for BALF. Associations of BAFF and APRIL levels with clinical measures were assessed to clarify their clinical roles.ResultsIn patients with APAP, serum BAFF and APRIL levels were significantly increased relative to healthy volunteers (p < 0.0001 and p < 0.05, respectively), and BALF BAFF and APRIL levels were significantly increased versus disease controls (p < 0.0001 and p < 0.01, respectively). Serum BAFF levels (but not APRIL levels) were significantly correlated with Krebs von den Lungen-6 (KL-6), surfactant protein (SP)-D, SP-A, and lactate dehydrogenase (p < 0.0001). There was no significant correlation between serum BAFF or APRIL levels and anti-GM-CSF autoantibody. BAFF and APRIL were negatively correlated with single-breath diffusion capacity for carbon monoxide (DLco) (p = 0.004) and forced vital capacity (p = 0.04), respectively. BAFF (but not APRIL) in BALF was negatively correlated with vital capacity (p = 0.04) and DLco (p = 0.006). There were significant correlations between disease severity and BAFF levels in serum (p = 0.04) and BALF (p = 0.007). Serum levels of anti-GM-CSF autoantibody, BAFF, and APRIL were not significantly affected by WLL or inhalation of recombinant human GM-CSF.ConclusionsBAFF and APRIL levels of sera and BALF in APAP were significantly increased compared with healthy volunteer and disease control, and the BAFF and APRIL pathway might have important specific roles in pathogenesis of APAP. Our data suggest a new perspective of future treatment for APAP.

The prognostic value of serum levels of a proliferation-inducing ligand (APRIL) in treatment-naïve patients with chronic lymphocytic leukemia

Background/aimA proliferation-inducing ligand (APRIL) has been investigated as a prognostic marker in chronic lymphocytic leukemia (CLL) patients. However, there is no cut-off level for serum APRIL (sAPRIL) levels that predict time to treatment in CLL patients. Materials and methodsBetween May and December 2012, 94 consecutive CLL patients and 25 healthy controls were assessed. sAPRIL levels were measured by ELISA. Demographic data and prognostic markers were obtained from the patients’ files. Treatment-naïve patients were followed up for 6.5 years for any treatment need.ResultsPatients were divided into 3 groups: Treatment-naïve (n = 47), chemotherapy receiving (n = 25), and those who had received chemotherapy previously (n = 22). There was no difference in median sAPRIL levels of patients who were receiving chemotherapy at the sampling time and the healthy controls, which indicates that sAPRIL levels might be influenced by treatment. For treatment-naïve patients, the best cut-off in predicting time to treatment was found at the sAPRIL level of 2.04 ng/mL, with 78% sensitivity and 63% specificity. Time to treatment was significantly earlier in the APRIL high group (n = 27) than in the APRIL low group (n = 20) (P = 0.010, log-rank test). ConclusionsAPRIL, a simple, promising blood test which can be measured by ELISA, will likely obtain a place in the wide range of prognostic markers in CLL. Prospective large-scale studies are required to validate and confirm the feasibility of the proposed cut-off level of 2.04 ng/mL as a predictor of time to treatment in treatment-naïve CLL patients.

Serum a proliferation-inducing ligand and MicroRNA-223 are associated with rheumatoid arthritis: diagnostic and prognostic implications

BackgroundCurrent blood-based tests for rheumatoid arthritis (RA) have inherent limitations, necessitating the need for additional new biomarkers for its diagnosis and monitoring disease activity and responsiveness to therapy. MicroRNAs (miRNAs) and a proliferation-inducing ligand (APRIL) are deregulated in RA and were linked to its pathogenesis. This study investigated serum levels of APRIL, miR-223 and miR-155 in RA patients, their potential as diagnostic and prognostic biomarkers, and their correlation with disease activity and clinicopathological data.MethodsOne hundred and twenty Egyptian patients with RA and 130 healthy controls were included. Serum miRNAs and APRIL were assayed by RT-qPCR and ELISA, respectively.ResultsSerum APRIL and miR-223 were significantly upregulated, while miR-155 was unchanged in RA patients compared to controls. Serum miR-223 discriminated RA patients from controls with AUC = 0.85, whereas serum APRIL superiorly distinguished the two groups with AUC = 1 (sensitivity and specificity = 100% at cutoff> 4.19 ng/ml) by receiver-operating-characteristic analysis. Serum miR-223 was a significant predictor for RA diagnosis in multivariate logistic regression analysis. In RA group, serum APRIL was positively correlated with disease activity score (DAS28-CRP). Serum miR-223 expression was positively correlated with serum miR-155, APRIL levels and with the presence of subcutaneous nodules. Serum miR-155 levels were correlated with antinuclear antibody titer in reverse direction.ConclusionOur results suggest serum APRIL and miR-223 could serve as potential biomarkers of RA, with miR-223 as a predictor of RA risk and APRIL as an excellent biomarker of disease activity. Our data could be implicated for accurate and blood-based non-invasive diagnosis and prognosis of RA.

Changes of B cell-activating factor and a proliferation-inducing ligand in serum of children with Hen(o)ch-Sch(o)nlein purpura nephritis

Objective To investigate the changes of B cell-activating factor (BAFF) and a proliferation- inducing ligand (APRIL) in serum of children with Henoch- Schonlein purpura nephritis (HSPN), and to explore their role in the pathogenesis of children HSPN. Methods A total of 28 children with HSPN who were before treatment were selected in Department of Pediatrics Nephrology and Rheumatology, Shengjing Hospital of China Medical University from November 2017 to August 2018.Sixteen children with Henoch-Schonlein purpura were selected as HSP group, and 20 healthy children were selected as healthy control group.Followed the HSPN guideline to cure the patients for 6-8 weeks.The clinical data were collected.Serum levels of BAFF and APRIL were measured by adopting enzyme-linked immunosorbent assay (ELISA). Results (1)Changes of serum BAFF level: the serum levels of BAFF in HSPN children were significantly lower than those in the HSP group and the healthy control group[ HSPN group (0.652±0.360) μg/L, HSP group (1.276±0.459) μg/L, healthy control group (1.285±0.299) μg/L, F=17.519, P=0.000]. Moreover, the serum levels of BAFF in before treatment were significantly lower than those in after treatment [before treatment (0.652±0.360) μg/L, after treatment (0.860±0.262) μg/L, P 0.05). (2)Changes of serum APRIL level: the serum levels of APRIL in HSPN and HSP children were both significantly higher than those in healthy control group, but there were no marked differences between the 2 groups [HSPN group (2.285±1.015) μg/L, HSP group (2.609±1.264) μg/L, healthy control group (1.677±0.118) μg/L, F=3.647, P=0.016]. There were no significant differences in the serum levels of APRIL between before treatment and after treatment [ before treatment (2.285±1.015) μg/L, after treatment (2.042±0.695) μg/L, P>0.05]. (3)Pearson correlation analysis results showed that the serum levels of BAFF were negatively correlated with 24 h urinary protein, urinary microalbumin, and urine red blood cell count (r=-0.587, -0.608, -0.515, all P<0.05). The serum levels of APRIL were positively correlated with serum IgA(r=0.588, P<0.05). Conclusions The level of serum BAFF decreased and APRIL increased in children with HSPN, which was related to the degree of renal involvement.It suggests that BAFF and APRIL may be related to the pathogenesis of HSPN in children. Key words: Henoch- Schonlein purpura nephritis; Child; B cell-activating factor; Proliferation-inducing ligand

TLR9 activation induces aberrant IgA glycosylation via APRIL- and IL-6–mediated pathways in IgA nephropathy

Galactose-deficient IgA1 (Gd-IgA1) plays a crucial role in the development of IgA nephropathy (IgAN). However, the pathogenic mechanisms driving Gd-IgA1 production have not been fully elucidated. Innate-immune activation via Toll-like receptor 9 (TLR9) is known to be involved in Gd-IgA1 production. A proliferation inducing ligand (APRIL) and IL-6 are also known to enhance Gd-IgA1 synthesis in IgAN. With this as background, we investigated how TLR9 activation in IgA secreting cells results in overproduction of nephritogenic IgA in the IgAN-prone ddY mouse and in human IgA1-secreting cells. Injection of the TLR9 ligand CpG-oligonucleotides increased production of aberrantly glycosylated IgA and IgG-IgA immune complexes in ddY mice that, in turn, exacerbated kidney injury. CpG-oligonucleotide-stimulated mice had elevated serum levels of APRIL that correlated with those of aberrantly glycosylated IgA and IgG-IgA immune complexes. Invitro, TLR9 activation enhanced production of the nephritogenic IgA as well as APRIL and IL-6 in splenocytes of ddY mice and in human IgA1-secreting cells. However, siRNA knock-down of APRIL completely suppressed overproduction of Gd-IgA1 induced by IL-6. Neutralization of IL-6 decreased CpG-oligonucleotide-induced overproduction of Gd-IgA1. Furthermore, APRIL and IL-6 pathways each independently mediated TLR9-induced overproduction of Gd-IgA1. Thus, TLR9 activation enhanced synthesis of aberrantly glycosylated IgA that, in a mouse model of IgAN, further enhanced kidney injury. Hence, APRIL and IL-6 synergistically, as well as independently, enhance synthesis of Gd-IgA1.

A proliferation-inducing ligand (APRIL) induced hyper-production of IgA from tonsillar mononuclear cells in patients with IgA nephropathy

IgA nephropathy (IgAN) is a tonsil-related disease. We previously showed that oligodeoxynucleotides with CpG (CpG-ODN) and B-cell activation factor (BAFF) are involved in hyperproduction of IgA from tonsillar mononuclear cells of patients with IgAN (IgAN-TMCs). In this study, we focused on a proliferation-inducing ligand (APRIL), homologous to BAFF. IgAN-TMCs produced more APRIL than non IgAN-TMCs in the presence of both CpG-ODN and control-ODN. TLR9 expression was higher in B-cells of IgAN-TMCs, and treatment with CpG-ODN enhanced transmembrane activator and CAML interactor (TACI) expression. IgA production from IgAN-TMCs was inhibited by APRIL neutralization antibody or TACI blocking antibody, and enhanced by co-treatment of APRIL and CpG-ODN. Serum APRIL levels were higher in patients with IgAN, and decreased after tonsillectomy. These findings suggest that APRIL is involved in the hyperproduction of IgA from IgAN-TMCs, and that CpG-ODN enhanced APRIL-induced IgA production by increasing TACI expression on B-cells of IgAN-TMCs.

Serum Levels of APRIL Increase in Patients with Glioma, Meningioma and Schwannoma

Objective:Brain tumors are of high mortality and morbidity for which there is still no cure. The TNF family cytokine, A Proliferation Inducing Ligand (APRIL), is shown to help proliferation and development of tumor cells. We assessed serum levels of APRIL in patients with glioma, meningioma and schwannoma in comparison to healthy individuals.Methods:Peripheral blood samples of 68 patients with brain tumors, divided into three groups of gliomas (n=25), meningiomas (n=30) and schwannomas (n=13), as well as 45 healthy individuals were obtained. Serum samples were prepared and stored in -40°C until usage. Using a commercial ELISA method, APRIL concentration was measured in each serum sample. The obtained data were then analyzed using SPSS software.Results:APRIL serum levels were higher in all patients compared to the controls (P<0.001). Moreover, APRIL serum levels were higher in each of the tumor bearing groups (gliomas, meningiomas and schwannomas) in comparison to the controls (P<0.001, <0.001 and =0.001, respectively). Comparing APRIL between the patients groups showed no significant difference. Age and gender showed no significant correlation with serum APRIL levels, although the age of patients in glioma group was significantly lower than controls (P=0.017). The serum APRIL levels in gliomas with histological grade showed no difference, but in meningiomas, it was lower in tumors with higher grades (P= 0.011).Conclusion:Increased serum levels of APRIL in patients with meningioma and schwannoma as well as glioma may indicate a common role of this cytokine in brain tumors.

Podgrupy pacjentów z zespołem Sjögrena klasyfikowane według obecności autoprzeciwciał – charakterystyka kliniczna i immunologiczna.

ObjectivesSjögren’s syndrome (SS) is an autoimmune disease characterised by heterogeneous clinical presentation and presence of various autoantibodies – anti-SSA/Ro of diagnostic value, less specific anti-SSB/La and others. We searched for biomarker(s) and potential therapeutic target(s) of SS subsets that vary in their autoantibody profile.Material and methodsEighty-one patients with SS (70 female and 11 male) and 38 healthy volunteers (28 female and 10 male) were included in the study. Patients were categorised according to absence (group 1) or presence of anti-SSA/Ro antibody which occurred either alone (group 2) or together with anti-SSB/La (group 3). Clinical evaluation was performed, and presence of autoantibodies and concentrations of cytokines relevant to SS pathogenesis, i.e. a proliferation inducing ligand (APRIL), B-lymphocyte activating factor (BAFF), interleukin (IL) 4, IL-10, interferon α (IFN-α) and thymic stromal lymphopoietin (TSLP), in sera were determined.ResultsFrequency of autoantibodies other than anti-SSA/Ro and anti-SSB/La, the number of autoantibody specificities and anti-nuclear antibody titres were higher in group 2 and/or 3 than in group 1 of SS patients. Moreover, SS patients of groups 2 and 3 developed disease symptoms at younger age, and more often had positive Schirmer’s test and skin lesions. In addition, serum concentrations of APRIL, but not other tested cytokines, were significantly higher in the patients of both groups 2 and 3 than those of group 1 and healthy volunteers.ConclusionsSjögren’s syndrome patients with signs of B-cell epitope spreading are characterised by early disease onset, more frequent xerophthalmia and skin involvement, and up-regulated serum APRIL level. We suggest that therapeutic neutralisation of APRIL may be beneficial for these patients.

APRIL Is Significantly Elevated at All Stages of Multiple Myeloma (MM) and Interferes with Anti-Bcma Monoclonal Antibody-Mediated Cytolysis, Supporting the Clinical Evaluation of Bion-1301 As a Novel Therapeutic Approach in MM

A proliferation inducing ligand (APRIL) is a natural ligand with higher affinity than BAFF for both B cell maturation antigen (BCMA) and transmembrane activator and CAML interactor (TACI), which are overexpressed on multiple myeloma (MM) cells. APRIL, which is abundantly secreted by myeloma-supporting osteoclasts and macrophages, promotes MM cell progression in vivo and further induces regulatory T cells (Treg) via TACI, but not BCMA, to promote an immunosuppressive MM bone marrow (BM) microenvironment (Blood 2017;130:3066). In preclinical studies, an antagonistic APRIL monoclonal antibody (mAb) significantly inhibited human MM cell growth in SCID-hu mice and abrogated APRIL-induced immunosuppression mediated by Tregs. Here we characterized the ability of BION-1301, a neutralizing APRIL mAb, currently under clinical development in MM (NCT03340883) to overcome protection conferred by APRIL against MM cell lysis induced by the anti-BCMA J6M0 mAb (Blood 2017 130:499).Our studies show that APRIL protects against MM cell lysis induced by J6M0 in the presence of FcR-expressing effector cells (PBMC, monocytes or NK), an effect which is blocked by neutralizing anti-APRIL mAb. APRIL also downregulates J6M0-induced cell membrane CD107a expression on NK cells co-cultured with BCMA-expressing MM cells, which is similarly abrogated by anti-APRIL mAb. Importantly, anti-APRIL mAb also significantly decreases protection conferred by osteoclasts against MM cell lysis induced by J6M0. These data indicate that blocking APRIL with anti-APRIL mAb may enhance BCMA mAb targeted (J6M0)-induced MM cell lysis. Next, using anti-human IgG1 to detect J6M0 binding to MM cell surface BCMA, we found that APRIL in a dose-dependent manner directly competes with J6M0 for binding to BCMA, which was confirmed by ELISA. In addition, APRIL effectively inhibits J6M0 binding to BCMA at 4°C, which argues against APRIL-induced BCMA receptor shedding and/or internalization. In contrast, BAFF affects J6M0 binding to BCMA only at higher concentrations (>1 µg/mL), consistent with > 2-log higher affinity of APRIL vs. BAFF for BCMA.We further assessed APRIL, BAFF, BCMA, and TACI levels in the serum of patients with MM at various stages of disease. Specifically, we used ELISA to measure free APRIL and the ELLA automated immunoassay platform to determine the levels of soluble BAFF, soluble BCMA, and soluble TACI in serum samples from patients with MM (n=193) as well as serum samples from healthy volunteers (HV, n=100). Patient samples included monoclonal gammopathy of undetermined significance (MGUS, n=12), smoldering MM (SMM, n=20), newly diagnosed MM (ND, n=39), post induction pre-autologous stem cell transplant (ASCT, n=55), post-ASCT (n=6), and relapsed refractory MM (RR, n=61). We found that free APRIL levels are significantly increased in serum samples from patients with MM at all stages of disease, when change from baseline levels were compared to those from HVs (post-ASCT: p=0.0003; other groups (MGUS, SMM, ND, pre-ASCT, and RR): p<0.0001). In contrast, average soluble BAFF levels gradually increase with progression of disease from 818.47 pg/mL at MGUS to 1685.50 pg/mL at RR MM. Both soluble BCMA and soluble TACI concentrations are highest in serum from a subset of patients with ND (593550 and 5999.63 pg/mL, respectively) and RR (1088897 and 5050.97 pg/mL, respectively) MM. A detailed analysis of clinical characteristics, treatment and response, as well as measurement of additional cytokines and chemokines is ongoing and will be reported when applicable.Our studies therefore indicate that therapies directed at the APRIL/BCMA and APRIL/TACI axes may simultaneously target MM cells and counteract APRIL-induced immunosuppression, and that combination strategies targeting APRIL with BCMA directed therapy may augment anti-MM activity. Moreover, elevated free APRIL serum levels in MGUS and all stages of MM suggest a role for APRIL in mediating immunosuppression during the development and in the pathogenesis of MM. DisclosuresDulos:Aduro Biotech: Employment. Guelen:Aduro Biotech Europe: Employment. van Zandvoort:Aduro Biotech Europe: Employment. van de Wiel:Aduro Biotech Europe: Employment. van de Crommert:Aduro Biotech Europe: Employment. Lejeune:Aduro Biotech Europe: Employment. Namini:Aduro Biotech: Employment. Eenennaam:Aduro Biotech Europe: Employment, Equity Ownership. van Elsas:Aduro Biotech Europe: Employment. Richardson:Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Karyopharm: Membership on an entity's Board of Directors or advisory committees; BMS: Research Funding; Jazz Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Membership on an entity's Board of Directors or advisory committees. Munshi:OncoPep: Other: Board of director. Anderson:Takeda Millennium: Consultancy; C4 Therapeutics: Equity Ownership; Bristol Myers Squibb: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy; Oncopep: Equity Ownership.

BAFF-R and TACI expression on CD3+ T cells: Interplay among BAFF, APRIL and T helper cytokines profile in systemic lupus erythematosus

BackgroundSystemic lupus erythematosus (SLE) is the prototype of systemic autoimmune disease, characterized by loss of immune tolerance against self-antigens where autoantibody production is the hallmark of disease. B-cell-activating factor (BAFF) and A proliferation-inducing ligand (APRIL) are cytokines that promote autoreactive cell survival, immunoglobulin-class switching and autoantibody responses in human and mouse SLE models. BAFF and APRIL exert their functions through interactions with their receptors BAFF-R and TACI that are differentially expressed in B lymphocyte subsets, monocytes, dendritic cells and T lymphocytes. BAFF stimulation favors T lymphocyte activation and cytokine production through BAFF-R, which could contribute to the Th1, Th17 and/or Th2 response dysregulation observed in SLE patients. ObjectiveTo evaluate the expression of the cytokines BAFF and APRIL and their association with the receptors BAFF-R and TACI on CD3+ T cells and to evaluate Th1/Th2/Th17 cytokine profile in patients with SLE. MethodsFifteen healthy controls (HC) and 36 SLE patients were included, and their demographic and clinical data were assessed. The disease activity index (Mex-SLEDAI) and damage index (SLICC) were applied to the SLE patients. BAFF-R and TACI expression on CD3+ T cells were evaluated by flow cytometry. Serum BAFF and APRIL concentrations were measured by enzyme-linked immunosorbent assays (ELISA). Cytokine levels of Th1 (IL-12, IL-2, IFN-γ, TNF-α), Th2 (IL-4, IL-6, IL-10, IL-13) and Th17 (IL-1β e IL-17) were quantified with a multiplex assay (MAGPIX). Statistical analysis was performed using PASW Statistics v.20 and GraphPad Prism v.6 software. ResultsNo differences in BAFF-R or TACI expression on the CD3+ T cells of SLE and HC were observed. BAFF-R expression correlates inversely with disease activity (r = −0.538, p < 0.01), while TACI correlates with disease activity (r = 0.530, p < 0.05). Serum BAFF and APRIL levels were high in SLE patients and correlated with the disease activity index Mex-SLEDAI (r = 0.621, p < 0.01 and r = 0.416, p < 0.05). SLE patients were found to have significantly higher levels of IL-12, IFN-γ, TNF-α, IL-6, IL-10, IL-13, IL-1β and IL-17 compared to HC (p < 0.05). Cytokines IL-17 (r = 0.526) and TNF-α (r = 0.410) correlate with disease activity (p < 0.05), while APRIL (r = 0.477), IL-10 (r = 0.426) and IFN-γ (r = 0.440) levels were associated with organ damage (p < 0.01). Serum BAFF expression levels correlate with IL-4 (r = 0.424; p < 0.05), IL-6 (r = 0.420; p < 0.05) and IL-10 (r = 0.459; p < 0.01), whereas APRIL levels correlate with IL-2 (r = 0.666; p < 0.01), IL-12 (r = 0.611; p < 0.01) and TNF-α (r = 0.471; p < 0.05) cytokines. A subgroup of SLE patients with high serum BAFF levels (>2 ng/mL) also showed increased APRIL, IL-2, IL-6 and IL-10 levels (p < 0.05). Finally, BAFF, IL-4 and TNF-α serum levels were associated with high titers of antinuclear antibodies. ConclusionsThe study demonstrates an imbalance in the Th1/Th2 cytokine profile, with increased proinflammatory cytokines, as well as BAFF and APRIL serum levels. Associations of BAFF with Th2 profile cytokines and disease activity, as well as APRIL with Th1 profile cytokines and organ damage, suggest that BAFF and APRIL generated in the autoimmunity context could through still unknown mechanisms, modulate the microenvironment, and perpetuate the inflammatory response, autoantibody production and organ damage observed in SLE patients.