B cell involvement in the pathogenesis of ankylosing spondylitis

Extensive research into ankylosing spondylitis (AS) has suggested the major role of genetics, immune reactions, and the joint–gut axis in its etiology, although an ultimate consensus does not yet exist. The available evidence indicates that both autoinflammation and T-cell-mediated autoimmune processes are actively involved in the disease process of AS. So far, B cells have received relatively little attention in AS pathogenesis; this is largely due to a lack of conventional disease-defining autoantibodies. However, against prevailing dogma, there is a growing body of evidence suggestive of B cell involvement. This is illustrated by disturbances in circulating B cell populations and the formation of auto-reactive and non-autoreactive antibodies, along with B cell infiltrates within the axial skeleton of AS patients. Furthermore, the depletion of B cells, using rituximab, displayed beneficial results in a subgroup of patients with AS. This review provides an overview of our current knowledge of B cells in AS, and discusses their potential role in its pathogenesis. An overarching picture portrays increased B cell activation in AS, although it is unclear whether B cells directly affect pathogenesis, or are merely bystanders in the disease process

Targeting plasma cells in systemic autoimmune rheumatic diseases:Promises and pitfalls

Plasma cells are the antibody secretors of the immune system. Continuous antibody secretion over years can provide long-term immune protection but could also be held responsible for long-lasting autoimmunity in case of self-reactive plasma cells. Systemic autoimmune rheumatic diseases (ARD) affect multiple organ systems and are associated with a plethora of different autoantibodies. Two prototypic systemic ARDs are systemic lupus erythematosus (SLE) and Sjögren's disease (SjD). Both diseases are characterized by B-cell hyperactivity and the production of autoantibodies against nuclear antigens. Analogues to other immune cells, different subsets of plasma cells have been described. Plasma cell subsets are often defined dependent on their current state of maturation, that also depend on the precursor B-cell subset from which they derived. But, a universal definition of plasma cell subsets is not available so far. Furthermore, the ability for long-term survival and effector functions may differ, potentially in a disease-specific manner. Characterization of plasma cell subsets and their specificity in individual patients can help to choose a suitable targeting approach for either a broad or more selective plasma cell depletion. Targeting plasma cells in systemic ARDs is currently challenging because of side effects or varying depletion efficacies in the tissue. Recent developments, however, like antigen-specific targeting and CAR-T-cell therapy might open up major benefits for patients beyond current treatment options.</p

Novel approaches for rescuing function of the salivary gland epithelium in primary Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterised by dysfunction and inflammatory lymphocytic infiltration of exocrine glands, namely the salivary and lacrimal glands. pSS patients often suffer from sicca (dry mouth) complaints, including dental caries, and difficulties in eating, sleeping and speaking. A large body of literature points to a central role for salivary gland (SG) epithelial cells in the development of this pathology. Here we summarise recent studies concerning the role of SG epithelial cells in pSS, which strongly indicate their intrinsic activation and early involvement during the disease process. Based on that, we propose possible future interventions targeting SG epithelial cells, to treat SG dysfunction pSS

The Effect of Two Years of Secukinumab Treatment on Bone Metabolism in Patients with Radiographic Axial Spondyloarthritis:Results from Daily Clinical Practice

Background: Our objective was to explore bone-related outcome and bone turnover markers (BTM) during 2 years of secukinumab treatment in patients with radiographic axial spondyloarthritis (r-axSpA) in daily clinical practice. Methods: Included were consecutive r-axSpA outpatients from the Groningen Leeuwarden axSpA (GLAS) cohort treated with secukinumab for 2 years. At baseline and 2 years, spinal radiographic damage was assessed using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS; 0–72), cervical facet joint involvement according the “de Vlam” scoring method (0–15) and radiographic vertebral fractures (VF) using the “Genant” method (grade 0–3). At all visits, BTM reflecting collagen resorption (serum type I collagen C-telopeptide; sCTX), collagen formation (procollagen type 1 N-terminal peptide; PINP) and bone mineralization (bone-specific alkaline phosphatase; BALP) were measured and expressed in Z-scores to correct for the normal influence of age and gender.Results: 17 r-axSpA patients were included; 53% male, mean age was 47±15 years, mean Ankylosing Spondylitis Disease Activity Score (ASDAS) 3.9±1.2, and 53% was biological naïve. The median 2-year progression rates were 1.1 for mSASSS and 0.5 for facet joints, which was less than the smallest detectable change. One traumatic VF (grade 3) occurred. Serum levels of sCTX and PINP remained stable during secukinumab treatment and BALP decreased significantly after 2 years, with median 0–2 year change in Z-scores of +0.1, −0.4, and −1.2, respectively.Conclusion: This explorative study of r-axSpA patients treated with secukinumab in daily clinical practice showed low radiographic spinal progression during 2 years of follow-up. Collagen resorption and formation markers remained stable, whereas mineralization marker BALP decreased significantly after 2 years. Our results are in line with the results of in vitro studies demonstrating that inhibition of IL17-A resulted in suppression of osteogenic differentiation with significant decrease in mineralization.</p

The Effect of Two Years of Secukinumab Treatment on Bone Metabolism in Patients with Radiographic Axial Spondyloarthritis:Results from Daily Clinical Practice

Background: Our objective was to explore bone-related outcome and bone turnover markers (BTM) during 2 years of secukinumab treatment in patients with radiographic axial spondyloarthritis (r-axSpA) in daily clinical practice. Methods: Included were consecutive r-axSpA outpatients from the Groningen Leeuwarden axSpA (GLAS) cohort treated with secukinumab for 2 years. At baseline and 2 years, spinal radiographic damage was assessed using the modified Stoke Ankylosing Spondylitis Spinal Score (mSASSS; 0–72), cervical facet joint involvement according the “de Vlam” scoring method (0–15) and radiographic vertebral fractures (VF) using the “Genant” method (grade 0–3). At all visits, BTM reflecting collagen resorption (serum type I collagen C-telopeptide; sCTX), collagen formation (procollagen type 1 N-terminal peptide; PINP) and bone mineralization (bone-specific alkaline phosphatase; BALP) were measured and expressed in Z-scores to correct for the normal influence of age and gender.Results: 17 r-axSpA patients were included; 53% male, mean age was 47±15 years, mean Ankylosing Spondylitis Disease Activity Score (ASDAS) 3.9±1.2, and 53% was biological naïve. The median 2-year progression rates were 1.1 for mSASSS and 0.5 for facet joints, which was less than the smallest detectable change. One traumatic VF (grade 3) occurred. Serum levels of sCTX and PINP remained stable during secukinumab treatment and BALP decreased significantly after 2 years, with median 0–2 year change in Z-scores of +0.1, −0.4, and −1.2, respectively.Conclusion: This explorative study of r-axSpA patients treated with secukinumab in daily clinical practice showed low radiographic spinal progression during 2 years of follow-up. Collagen resorption and formation markers remained stable, whereas mineralization marker BALP decreased significantly after 2 years. Our results are in line with the results of in vitro studies demonstrating that inhibition of IL17-A resulted in suppression of osteogenic differentiation with significant decrease in mineralization.</p