Dysregulated Fcγ receptor IIa-induced cytokine production in dendritic cells of lupus nephritis patients.

Systemic lupus erythematosus (SLE) is an autoimmune disease of unknown etiology. One of the key factors associated with SLE pathogenesis is excessive production of type I interferons (IFNs). This could result from increased activation of type I IFN-stimulating pathways, but also from decreased activation of type I IFN-inhibitory pathways. Recently, we have identified that immunoglobulin (Ig)G immune complexes strongly inhibit type I IFN production in healthy individuals by inhibitory signaling through Fcγ receptor IIa (FcγRIIa) on dendritic cells (DCs). Because, in SLE patients, immune complexes are characteristically present, we assessed whether FcγR-induced suppression of type I IFN is functional in DCs of SLE patients. We divided the SLE patients into one group without, and one group with, previous major organ involvement, for which we chose nephritis as a prototypical example. We show that DCs of lupus nephritis patients displayed impaired FcγR-mediated type I IFN inhibition compared to SLE patients without major organ involvement or healthy controls. We verified that this impaired type I IFN inhibition was not related to differences in disease activity, medication, FcγRIIa expression or expression of IFN regulatory transcription factors (IRF)1 and IRF5. In addition, we identified that DCs of lupus nephritis patients show increased FcγR-induced interleukin (IL)-1ß production, which is another important cytokine that promotes kidney inflammation. Taken together, these data indicate that DCs of lupus nephritis patients display altered FcγR-mediated regulation of cytokine production, resulting in elevated levels of type I IFN and IL-1ß. This dysregulation may contribute to the development of nephritis in SLE patients.

An add-on training program involving breathing exercises, cold exposure, and meditation attenuates inflammation and disease activity in axial spondyloarthritis - A proof of concept trial.

OBJECTIVES: The primary objective of this trial was to assess safety and anti-inflammatory effects of an add-on training program involving breathing exercises, cold exposure, and meditation in patients with axial spondyloarthritis. METHODS: This study was an open-label, randomised, one-way crossover clinical proof-of-concept trial. Twenty-four patients with moderately active axial spondyloarthritis(ASDAS >2.1) and hs-CRP ≥5mg/L were included and randomised to an intervention (n = 13) and control group (n = 11) group that additionally received the intervention after the control period. The intervention period lasted for 8 weeks. The primary endpoint was safety, secondary endpoints were change in hs-CRP, serum calprotectin levels and ESR over the 8-week period. Exploratory endpoints included disease activity measured by ASDAS-CRP and BASDAI, quality of life (SF-36, EQ-5D, EQ-5D VAS), and hospital anxiety and depression (HADS). RESULTS: We found no significant differences in adverse events between groups, with one serious adverse event occurring 8 weeks after end of the intervention and judged 'unrelated'. During the 8-week intervention period, there was a significant decline of ESR from (median [interquartile range] to 16 [9-26.5] to 9 [5-23] mm/hr, p = 0.040, whereas no effect was found in the control group (from 14 [8.3-27.3] to 16 [5-37] m/hr, p = 0.406). ASDAS-CRP declined from 3.1 [2.5-3.6] to 2.3 [1.9-3.2] in the intervention group (p = 0.044). A similar trend was observed for serum calprotectin (p = 0.064 in the intervention group versus p = 0.182 in the control group), but not for hs-CRP. CONCLUSIONS: This proof-of-concept study in axial spondyloarthritis met its primary endpoint with no safety signals during the intervention. There was a significant decrease in ESR levels and ASDAS-CRP upon the add-on training program in the intervention group. These findings warrant full-scale randomised controlled trials of this novel therapeutic approach in patients with inflammatory conditions. TRIAL REGISTRATION: ClinicalTrials.gov; NCT02744014.

Enhanced costimulation by CD70+ B cells aggravates experimental autoimmune encephalomyelitis in autoimmune mice.

OBJECTIVE: Assess whether CD70+ B cells contribute to EAE. MATERIALS AND METHODS: MOG-specific TCR transgenic mice (2D2) were crossed with mice with constitutive CD70 expression on B cells. The development of EAE and the phenotype of B-T lymphocytes were studied in 2D2xCD70 animals. RESULTS: Spontaneous EAE developed in 20% of 2D2xCD70 and 3% of 2D2 mice. EAE was also more severe in 2D2xCD70 versus 2D2 animals upon MOG immunization. The susceptibility of 2D2xCD70 to EAE was associated with fewer FoxP3+ T cells. CONCLUSIONS: Expression of CD70 by B cells aggravates EAE possibly by reducing the number of regulatory T cells.

Biologics for rare inflammatory diseases: TNF blockade in the SA PHO syndrome.

INTRODUCTION: SAPHO is an invalidating syndrome characterised by Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis. The low prevalence and heterogeneous presentation often leads to a significant diagnostic delay. Here, we provide an up-to-date overview of current insights into the pathogenesis and different treatment options. In addition, we describe the effects of anti-TNF treatment in three refractory cases. CASE REPORTS: Patient A is a 25-year-old female with hidradenitis suppurativa, inflammatory back pain and painful joints. After diagnosis, anti-TNF treatment was started resulting in clinical improvement. Patient B is a 44-year-old woman who presented with acne, palmoplantar pustulosis and anterior chest wall pain. Bone scintigraphy showed increased uptake at the anterior chest wall. Treatment with bisphosphonates resulted in temporary improvement and subsequent treatment with anti-TNF induced long-term clinical improvement. Patient C is a 37-year-old woman with palmoplantar psoriasis, relapsing hidradenitis and inflammatory back pain. MRI revealed osteitis of the pubic bone. Anti-TNF was started for SAPHO syndrome. However, despite a clinical response, our patient discontinued treatment, resulting in rapid deterioration. Anti-TNF treatment was re-introduced followed by clinical improvement. CONCLUSION: These case reports illustrate, consistent with the current literature, that TNF blockers can be considered for treatment of refractory SAPHO syndrome.

Systematic validation of specific phenotypic markers for in vitro polarized human macrophages.

BACKGROUND: Polarization of macrophages by specific micro-environmental conditions impacts upon their function following subsequent activation. This study aimed to systematically validate robust phenotypic markers for in vitro polarized human macrophages in order to facilitate the study of macrophage subsets in vivo. METHODS: Human peripheral blood monocytes were polarized in vitro with IFN-γ, IL-4, or IL-10. Similar experiments were performed with TNF, IL-13, dexamethasone, M-CSF and GM-CSF as polarizing stimuli. Phenotypic markers were assessed by flow cytometry and qPCR. RESULTS: IFN-γ polarized macrophages (MΦ(IFN-γ)) specifically enhanced membrane expression of CD80 and CD64, IL-4 polarized macrophages (MΦ(IL-4)) mainly upregulated CD200R and CD206, and downregulated CD14 levels, and IL-10 polarized macrophages (MΦ(IL-10)) selectively induced CD163, CD16, and CD32. The expression profiles of the most specific markers were confirmed by qPCR, dose-response experiments, and the use of alternative polarizing factors for each macrophage subset (TNF, IL-13, and dexamethasone, respectively). GM-CSF polarized macrophages (MΦ(GM-CSF)) upregulated CD80 but not CD64 expression, showing a partial phenotypic similarity with MΦ(IFN-γ), and also upregulated the expression of the alternative activation marker CD206. M-CSF polarized macrophages (MΦ(M-CSF)) not only expressed increased levels of CD163 and CD16, resembling MΦ(IL-10,) but also displayed high levels of CD64. The phenotype of MΦ(M-CSF) could be further modulated by additional polarization with IFN-γ, IL-4, or IL-10, whereas MΦ(GM-CSF) showed less phenotypic plasticity. CONCLUSION: This study validated CD80 as the most robust phenotypic marker for human MΦ(IFN-γ), whereas CD200R was upregulated and CD14 was specifically downregulated on MΦ(IL-4). CD163 and CD16 were found to be specific markers for MΦ(IL-10). The GM-CSF/M-CSF differentiation model showed only a partial phenotypic similarity with the IFN-γ/IL-4/IL-10 induced polarization.

New-onset polyarthritis during successful treatment of hidradenitis suppurativa with infliximab.

BACKGROUND: Hidradenitis suppurativa (HS) can be associated with several forms of arthritis, usually considered as reactive arthritis. A new observation is that some patients with HS develop arthritis after treatment with infliximab (antitumour necrosis factor-α). OBJECTIVES: A retrospective study was performed to establish the frequency and clinical presentation of new-onset arthritis during infliximab treatment. METHODS: Between 2005 and 2009, 27 individuals with severe HS were treated with infliximab and followed up closely. Laboratory parameters and side-effects were recorded. The frequency of arthritis was compared with control groups consisting of 227 patients with HS not treated with any biological, 22 patients with HS treated with adalimumab and 28 patients with psoriasis treated with infliximab, in the same period at the same clinic. RESULTS: Five of the 27 patients with HS (18%) treated with infliximab developed an acute and painful polyarthritis during treatment. The arthritis occurred on average after 12 months of treatment, was not clearly associated with anti-infliximab antibodies and resolved on average after 4 months. Interestingly, none of the patients had suffered from arthritis before despite the long duration of HS and all showed a good skin response to infliximab. Moreover, arthritis was not observed in any of the control groups. Compared with the adalimumab group and the psoriasis group, odds ratios of 7·241 [95% confidence interval (CI) 1·15-45·6] and 9·025 (95% CI 1·45-55·82) were calculated. CONCLUSIONS: The five cases described in this article suggest that infliximab treatment in HS can induce a transient but severe polyarthritis. The underlying mechanisms remain to be investigated further.

Pneumococcal aortitis: an insidious diagnosis.

A patient with Streptococcus pneumoniae aortitis is presented. Because of nonspecific symptoms (fever and back pain) there was a long diagnostic delay. In addition, the aortitis was located near the renal arteries which severely hampered early surgical treatment. Although emergency surgery was performed when aortic rupture occurred, the patient did not survive. Infectious arteritis of large vessels is a diagnosis often made late and associated with high mortality.

Differences in pathophysiology between rheumatoid arthritis and ankylosing spondylitis.

Rheumatoid arthritis and ankylosing spondylitis are common and severe chronic inflammatory skeletal diseases. Recognizing the differences rather than emphasizing similarities is important for a better understanding of the disease processes, the identification of specific therapeutic targets and in the long-term better treatment options for the individual patients. We discuss a number of pathophysiological differences between rheumatoid arthritis and ankylosing spondylitis by looking at the anatomical characteristics, differences and similarities in the autoimmune and autoinflammatory reactions, association with other immune mediated inflammatory diseases, structural outcome, and their potential significance for further therapeutic developments. Further research into the differences between these diseases should focus on the specific nature of the immune/inflammatory components, the role of resident cells in the joint and joint-associated tissues, the types and mechanisms of tissue remodeling and the characteristics of the articular cartilage. Better insights into their individual characteristics may lead to better therapeutic strategies, specific targets and useful biomarkers.