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Abstract Introduction The standard therapy for bronchial asthma consists of combinations of acute (short-acting ß2-sympathomimetics) and, depending on the severity of disease, additional long-term treatment (including inhaled glucocorticoids, long-acting ß2-sympathomimetics, anticholinergics, anti-IL-4R antibodies). The antidepressant amitriptyline has been identified as a relevant down-regulator of immunological TH2-phenotype in asthma, acting—at least partially—through inhibition of acid sphingomyelinase (ASM), an enzyme involved in sphingolipid metabolism. Here, we investigated the non-immunological role of amitriptyline on acute bronchoconstriction, a main feature of airway hyperresponsiveness in asthmatic disease. Methods After stimulation of precision cut lung slices (PCLS) from mice (wildtype and ASM-knockout), rats, guinea pigs and human lungs with mediators of bronchoconstriction (endogenous and exogenous acetylcholine, methacholine, serotonin, endothelin, histamine, thromboxane-receptor agonist U46619 and leukotriene LTD4, airway area was monitored in the absence of or with rising concentrations of amitriptyline. Airway dilatation was also investigated in rat PCLS by prior contraction induced by methacholine. As bronchodilators for maximal relaxation, we used IBMX (PDE inhibitor) and salbutamol (ß2-adrenergic agonist) and compared these effects with the impact of amitriptyline treatment. Isolated perfused lungs (IPL) of wildtype mice were treated with amitriptyline, administered via the vascular system (perfusate) or intratracheally as an inhalation. To this end, amitriptyline was nebulized via pariboy in-vivo and mice were ventilated with the flexiVent setup immediately after inhalation of amitriptyline with monitoring of lung function. Results Our results show amitriptyline to be a potential inhibitor of bronchoconstriction, induced by exogenous or endogenous (EFS) acetylcholine, serotonin and histamine, in PCLS from various species. The effects of endothelin, thromboxane and leukotrienes could not be blocked. In acute bronchoconstriction, amitriptyline seems to act ASM-independent, because ASM-deficiency (Smdp1−/−) did not change the effect of acetylcholine on airway contraction. Systemic as well as inhaled amitriptyline ameliorated the resistance of IPL after acetylcholine provocation. With the flexiVent setup, we demonstrated that the acetylcholine-induced rise in central and tissue resistance was much more marked in untreated animals than in amitriptyline-treated ones. Additionally, we provide clear evidence that amitriptyline dilatates pre-contracted airways as effectively as a combination of typical bronchodilators such as IBMX and salbutamol. Conclusion Amitriptyline is a drug of high potential, which inhibits acute bronchoconstriction and induces bronchodilatation in pre-contracted airways. It could be one of the first therapeutic agents in asthmatic disease to have powerful effects on the TH2-allergic phenotype and on acute airway hyperresponsiveness with bronchoconstriction, especially when inhaled.

Abstract Background The objective of this initiative was to develop a treat-to-target (T2T) approach for the management of patients with Familial Mediterranean Fever (FMF), including the definition of a complex treatment target, and establish strategies that improve patient care and long-term outcome. Methods An initial set of statements as well as a flow chart visualising the proposed concept was developed. To adapt the preliminary statements to the current state of knowledge, a systematic literature search was performed and the modified statements were subject to a Delphi approach. To ensure the applicability of the statements in daily practice, an online survey was conducted among paediatric rheumatologists in Germany. In addition, data from the national AID-NET registry were analysed with respect to therapeutic response. Results This T2T initiative yielded a total of 26 statements guiding FMF management with respect to diagnosis, treatment targets, treatment strategies and monitoring. The online survey identified cut-off values for inflammatory markers indicating treatment intensification and appropriate measures in case of colchicine intolerance or non-adherence. The analysis of data derived from the national AID-NET showed that colchicine therapy was successfully terminated in 61% of patients (27 out of 44) with heterozygous MEFV mutations. Multidimensional treatment targets incorporating objective and subjective reported outcome measures were developed. These provide the basis for stratifying patients into the following treatment paths: continue colchicine, persisting attacks / inflammation, colchicine intolerance, persisting arthritis, colchicine reduction and adjustment/reduction of biologics. Conclusions The proposed consensus treatment plan for the management of FMF incorporates multidimensional targets allowing transparent treatment decisions, which will promote personalised disease management and increase adherence to therapy.

Anorexia nervosa (AN) is a severe eating disorder that predominantly affects females and typically manifests during adolescence. There is increasing evidence that serum cytokine levels are altered in individuals with AN. Previous research has largely focused on adult patients, assuming a low-grade pro-inflammatory state. The serum levels of the cytokine tumour necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6 and IL-15, which are pro-inflammatory, were examined in 63 female adolescents with AN and 41 age-matched healthy controls (HC). We included three time points (admission, discharge, and 1-year follow-up) and investigated the clinical data to assess whether the gut microbiota was associated with cytokine alterations. Relative to the HC group, serum levels of IL-1β and IL-6 were significantly lower during the acute phase (admission) of AN. IL-1β expression was normalised to control levels after weight recovery. TNF-α levels were not significantly different between the AN and HC groups. IL-15 levels were significantly elevated in patients with AN at all time points. We found associations between cytokines and bodyweight, illness duration, depressive symptoms, and the microbiome. In contrast to most findings for adults, we observed lower levels of the pro-inflammatory cytokines IL-1β and IL-6 in adolescent patients, whereas the level of IL-15 was consistently increased. Thus, the presence of inflammatory dysregulation suggests a varied rather than uniform pro-inflammatory state.

Abstract Tofactinib is a JAK inhibitor approved for ulcerative colitis in humans. Despite of its’ proven effectiveness in humans, mechanistic data are scarce on the effectiveness of Tofactinib in experimental colitis in mice. We induced experimental colitis by transfer of CD4+CD25− isolated T cells into RAG2−/− (T and B cell deficient) mice and treated these mice with tofacitinib for 5–6 weeks either with a dosage of 10 or 40 mg/kg body weight immediately after CD4+ transfer or started treatment after first symptoms of disease for several weeks. While treatment with tofacitinib immediately after transfer resulted in an enhanced expansion of CD4+ T cells and did not prevent occurrence of colitis, treatment after start of symptoms of colitis ameliorated disease activity on a clinical basis and in histological analyses. Tofacitinib is effective in the treatment of murine experimental T cell transfer colitis, however does not prevent occurrence of disease.

Summary: Background: Treatment with elexacaftor/tezacaftor/ivacaftor (ETI) improves multiple clinical outcomes in people with cystic fibrosis (pwCF) with at least one F508del allele. This study evaluated the real-world impact of ETI on lung function, nutritional status, pulmonary exacerbation frequency, and sweat chloride concentrations in a large group of pwCF. Methods: This observational cohort study used data from the German CF Registry for pwCF who received ETI therapy and were followed up for a period of 12 months. Findings: The study included 2645 pwCF from 67 centres in Germany (mean age 28.0 ± 11.5 years). Over the first year after ETI was initiated, percent predicted forced expiratory volume in 1 s (ppFEV1) increased by 11.3% (95% confidence interval [CI] 10.8–11.8, p

Abstract Background To analyze therapy adherence, safety, and outcome in adult patients with juvenile idiopathic arthritis (JIA) treated with the etanercept biosimilar Benepali® (Biogen Inc, Cambridge, USA). Methods Data from the prospective registry, JuMBO (Juvenile arthritis MTX/Biologics long-term Observation), were used for the analysis. JuMBO is a long-term observational cohort study. It follows adult patients with JIA who were formerly included in the national JIA biologic register (BiKeR Registry). Both registries provide individual trajectories of clinical data and outcomes from childhood to adulthood in JIA patients treated with disease-modifying anti-rheumatic drugs (DMARDs). Results Eighty-three patients from the German JuMBO registry were treated with Benepali®. Of these, 74% had switched from Enbrel® (Pfizer Inc., NYC, USA) the originator of etanercept to Benepali® for cost reasons. Therapy survival of patients treated with Benepali® in comparison to Enbrel® in patients matched by significant parameters was comparable. Adverse events (AE) were reported in 25.3% and serious adverse events (SAE) in 9.6% of patients. Physicians rated no SAE causative related to Benepali®. The majority of SAEs were surgical/medical procedures and there was only one infection. All efficacy parameters (cJADAS-10, Physician Global Assessment, number of joints with active arthritis, patients’ overall well-being, pain, and HAQ) demonstrated improvement over 24 months (p-values were not significant). 9.6% of patients permanently discontinued Benepali® because of an AE. Conclusions Tolerability and effectiveness of the biosimilar Benepali® were satisfactory and therapy survival was comparable to the originator. Further data on therapy with biologics and biosimilars such as Benepali® must be collected by registries such as BiKeR and JuMBO in order to optimize therapy and patient outcomes and to reduce costs in the health system in the long term.

ObjectivesCD4+ memory T cells facilitate long-termed adaptive immune responses while NK cells are predominately rapid effector cells with significant functions for both intestinal homeostasis and inflammation. We wanted to study both populations in health and pediatric inflammatory bowel disease (IBD) and correlate them with disease activity and medication.MethodsWe performed flow cytometric analyses of peripheral blood CD4 + CD45RO+ memory T cells and CD3-CD16 + CD56+ NK cells in 30 patients with IBD and 31 age-matched controls and correlated percentages of subsets with disease activity (PUCAI/PCDAI) and medication.ResultsWe found a significant reduction of peripheral NK cells in overall IBD patients with both clinical remission and disease activity, which was even more pronounced in patients treated with azathioprine. Otherwise, circulating CD4+ memory T cell populations were significantly enhanced in active IBD compared to controls. Enhancement of memory T cells was particularly found in new onset disease and correlated with disease activity scores.DiscussionOur single center cohort confirms previous results showing enhanced memory T cell populations in pediatric IBD patients, which correlate with disease activity scores. CD4+ memory T cells are a relevant pathogenic leukocyte population for disease development and perpetuation in IBD. In addition, we found a decrease of NK cells in IBD patients, which was pronounced by use of azathioprine. Surveillance of both cellular populations could possibly serve as biomarker for therapy control in pediatric IBD.

Background and objectiveSickle cell disease (SCD) is a very common autosomal recessive hemoglobinopathy leading to multiple pulmonary complications that are closely associated with mortality. The pathophysiology of chronic pulmonary involvement is not yet fully understood and no specific therapies are available.MethodsThe aim of this cross-sectional study was to characterize the lung function of children and young adolescents with SCD in a German single-center cohort and to extend conventional lung function testing by the use of a new imaging method. We performed spirometry and body plethysmography in 35 children and young adults with hemoglobin SS, SC, S/β-thalassemia as well as 50 controls. These data were compared with clinical characteristics and typical laboratory parameters of hemolysis and disease activity in SCD. To identify lung inhomogeneities, for example due to atelectasis, hyperinflation, air trapping or vascular occlusions, we used the promising new method of electrical impedance tomography (EIT) and calculated global inhomogeneity indices.ResultsLung function of patients with SCD was significantly reduced compared to that of healthy controls. When the result was found to be pathological, the most commonly observed type of breathing disorder was classified as restrictive. Laboratory parameters showed typical features of SCD including decreased levels of hemoglobin and hematocrit and elevated levels of leucocytes, platelets, lactate dehydrogenase and total bilirubin. However, there was no correlation between blood values and reduced lung function. Electrical impedance tomography (EIT) revealed no abnormalities in SCD patients compared to healthy controls. In particular, we were unable to demonstrate any regional inhomogeneities in lung ventilation.ConclusionIn our study, SCD patients showed impaired lung function, with a relevant percentage of patients suffering from restrictive breathing disorder. Signs of obstruction could not be detected. Electrical impedance tomography (EIT) measurements revealed no unevenness that would suggest air entrapment, blockage of blood vessels, excessive inflation, obstruction, or other forms of lung disease. Additionally, the reduction in lung function observed in SCD patients was not related to the disease severity or laboratory test results.

It is well established that the neonatal immune system is different from the adult immune system. A major task of the neonatal immune system is to bridge the achievement of tolerance towards harmless antigens and commensal bacteria while providing protection against pathogens. This is highly important because neonates are immunologically challenged directly after birth by a rigorous change from a semi-allogeneic sterile environment into a world rich with microbes. A so called disease tolerogenic state is typical for neonates and is anticipated to prevent immunopathological damage potentially at the cost of uncontrolled pathogen proliferation. As a consequence, neonates are more susceptible than adults to life-threatening infections. At the basis of a well-functioning immune response, both for adults and neonates, innate immune cells such as monocytes and monocyte-derived macrophages play an essential role. A well-responsive monocyte will alter its cellular metabolism to subsequently induce certain immune effector function, a process which is called immunometabolism. Immunometabolism has received extensive attention in the last decade; however, it has not been broadly studied in neonates. This review focuses on carbohydrate metabolism in monocytes and macrophages in neonates. We will exhibit pathways involving glycolysis, the tricarboxylic acid (TCA) cycle and oxidative phosphorylation and their role in shaping neonates’ immune systems to a favorable tolerogenic state. More insight into these pathways will elucidate potential treatments targets in life-threatening conditions including neonatal sepsis or expose potential targets which can be used to induce tolerance in conditions where tolerance is harmfully impaired such as in autoimmune diseases.

IntroductionAnorexia nervosa (AN) is an often chronic and debilitating psychiatric disease whose etiology is not completely understood. Recently, a potential role of inflammation has emerged in other psychiatric diseases, such as depression, PTSD and schizophrenia. The first results in adults with AN seemed to confirm a low-grade proinflammatory state until recent studies presented more differential findings. Studying adolescents with a shorter illness duration and fewer confounding factors might help elucidate the role of inflammation in the underlying pathophysiology of AN; however, the few available studies in adolescents remain ambiguous, and no longitudinal data are available in this age range.MethodsWe examined the proinflammatory cytokines Tumor Necrosis Factor-alpha (TNF-α), Interleukin (IL)-1β, IL-6, IL-15, and the cytokine-receptor IL-6 Receptor alpha (IL-6 Rα) in the serum of twenty-two hospitalized female adolescent patients with AN longitudinally at admission and discharge and compared their results to nineteen healthy controls (HC). We also collected clinical data and stool samples that were analyzed with 16S rRNA amplicon sequencing to explore potential influencing factors of cytokine changes.ResultsTNF-α serum levels were significantly elevated in patients with AN at admission, while IL-1β and IL-6 levels were lower at admission and discharge than in HC. After treatment, we also found significantly elevated levels of IL-6 Rα compared to HC, while IL-15 did not show significant changes. Exploratory analyses revealed positive associations of cytokine and genus-level changes between admission and discharge for IL-1β (Bacteroides) and IL-15 (Romboutsia), and negative associations for IL-15 (Anaerostipes) and TNF-α (uncultured Lachnospiraceae).ConclusionWe confirmed a previous finding of elevated levels of TNF-α also in adolescents with AN; however, the reduced IL-1β and IL-6 levels differed from the mostly increased levels found in adults. A mixed pro- and anti-inflammatory state appears to be present in adolescents, potentially due to their shorter illness duration. The gut microbiota, with its regulatory function on cytokine production, might play a role in mediating these inflammatory processes in AN and could offer targets for new therapeutic approaches.

Abstract Background Systemic juvenile idiopathic arthritis (sJIA) is a complex disease with dysregulation of the innate immune system driven by cytokines. A major role is ascribed to interleukin-1β (IL-1β), supporting the autoinflammatory character of the disease and offering an effective blocking mechanism for treatment. Here we present clinical practice data from the German AID-registry for patients treated with IL-1 inhibition (IL-1i). Methods In 2009 a clinical and research consortium (AID-Net) was established, including an online AID-registry. Patients with documented sJIA diagnosis were identified. Data for this retrospective IL-1i study were recorded by 17 centers. Response to treatment was evaluated according to Wallace criteria and additionally by an own classifying clinical response system. Results In 6 years, 202 patients with confirmed sJIA were recorded in the AID-registry. Out of these, 111 children received therapy with Anakinra (ANA) (n = 84, 39 f) and/or Canakinumab (CANA) (n = 27, 15 f) at a median age of 8.7 y (range 0.6–19.1). During the first 12 months 75/111 (ANA 55, CANA 20) patients were evaluated according to Wallace criteria (achievement of inactive disease 28/55 and 17/20, remission over 6 months under medication 13/55 and 7/20 cases). Over the whole period of time, clinical response was preserved in the majority of patients (ANA 54/80, CANA 20/27). Arthritis mostly persisted in polyarticular (PA) courses. During treatment with IL-1i concomitant medication could be tapered in about 15%. IL-1i was discontinued in 59/111 patients. 45 (15) adverse events (AE)s in ANA (CANA) treated patients (19.7 (26.6) AE/100 ANA (CANA) exposure years, 95%CI: 14.4–26.4 (14.9–43.9)) were reported. Conclusion In a large cohort of sJIA patients from Germany, we can confirm an overall favorable clinical response to both available IL-1 blocking agents. IL-1i was well tolerated with acceptable safety and effectiveness in a real-life clinical setting.

BackgroundTo describe treatment practices for juvenile proliferative lupus nephritis (LN) class III and IV of pediatric rheumatologists and nephrologists in Germany and Austria in preparation for a treat-to-target treatment protocol in LN.MethodsSurvey study by members of the Society for Pediatric and Adolescent Rheumatology (GKJR) and the German Society for Pediatric Nephrology (GPN) on diagnostics and (concomitant) therapy of LN.ResultsFifty-eight physicians completed the survey. Overall, there was a considerable heterogeneity regarding the suggested diagnostics and management of juvenile proliferative LN. Increased urinary protein excretion, either assessed by 24 h urine collection or spot urine (protein-creatinine ratio), and reduced estimated glomerular filtration rate were specified as important parameters for indication of kidney biopsy to diagnose proliferative LN and monitoring of therapy. Corticosteroids were generally proposed for induction and maintenance therapy, most often in conjunction with either mycophenolate mofetil (MMF) or cyclophosphamide (CP) as steroid-sparing immunosuppressants. MMF was clearly preferred over CP for induction therapy of LN class III, whereas CP and MMF were equally proposed for LN class IV. MMF was most often recommended for maintenance therapy in conjunction with oral corticosteroids and continued for at least 3 years and 1 year, respectively, after remission. Hydroxychloroquine was widely accepted as a concomitant measure followed by renin-angiotensin system inhibitors in cases of arterial hypertension and/or proteinuria.ConclusionThe majority of pediatric rheumatologists and nephrologists in Germany and Austria propose the use of corticosteroids, most often in combination with either MMF or CP, for treatment of proliferative LN in children. The considerable heterogeneity of responses supports the need for a treat-to-target protocol for juvenile proliferative LN between pediatric rheumatologists and nephrologists.

Background: CD4+ T cells critically contribute to the initiation and perturbation of inflammation. When CD4+ T cells enter inflamed tissues, they adapt to hypoxia and oxidative stress conditions, and to a reduction in nutrients. We aimed to investigate how this distinct environment regulates T cell responses within the inflamed joints of patients with childhood rheumatism (JIA) by analyzing the behavior of NRF2—the key regulator of the anti-oxidative stress response—and its signaling pathways. Methods: Flow cytometry and quantitative RT-PCR were used to perform metabolic profiling of T cells and to measure the production of inflammatory cytokines. Loss of function analyses were carried out by means of siRNA transfection experiments. NRF2 activation was induced by treatment with 4-octyl-Itaconate (4-OI). Results: Flow cytometry analyses revealed a high metabolic status in CD4+ T cells taken from synovial fluid (SF) with greater mitochondrial mass, and increased glucose and fatty acid uptake. This resulted in a heightened oxidative status of SF CD4+ T cells. Despite raised ROS levels, expression of NRF2 and its target gene NQO1 were lower in CD4+ T cells from SF than in those from blood. Indeed, NRF2 activation of CD4+ T cells downregulated oxidative stress markers, altered the metabolic phenotype and reduced secretion of IFN-γ. Conclusion: NRF2 could be a potential regulator in CD4+ T cells during chronic inflammation and could instigate a drift toward disease progression or regression, depending on the inflammatory environment.

Neonatal immune responses are known to differ to those of an adult immune response. Here Dreschers and colleagues, compare macrophage populations derived from cord blood or adult peripheral blood and show a metabolic impairment of glycolysis in macrophages derived from cord blood which may impair response to infective scenarios such as sepsis.

Abstract Background The acute respiratory distress syndrome (ARDS) is a serious disease in critically ill patients that is characterized by pulmonary dysfunctions, hypoxemia and significant mortality. Patients with immunodeficiency (e.g. SCID with T and B cell deficiency) are particularly susceptible to the development of severe ARDS. However, the role of T cells on pulmonary dysfunctions in immune-competent patients with ARDS is only incompletely understood. Methods Wild-type (wt) and RAG2−/− mice (lymphocyte deficient) received intratracheal instillations of LPS (4 mg/kg) or saline. On day 1, 4 and 10 lung mechanics and bronchial hyperresponsiveness towards acetylcholine were measured with the flexiVent ventilation set-up. The bronchoalveolar lavage fluid (BALF) was examined for leukocytes (FACS analysis) and pro-inflammatory cytokines (ELISA). Results In wt mice, lung mechanics, body weight and body temperature deteriorated in the LPS-group during the early phase (up to d4); these alterations were accompanied by increased leukocyte numbers and inflammatory cytokine levels in the BALF. During the late phase (day 10), both lung mechanics and the cell/cytokine homeostasis recovered in LPS-treated wt mice. RAG2−/− mice experienced changes in body weight, lung mechanics, BAL neutrophil numbers, BAL inflammatory cytokines levels that were comparable to wt mice. Conclusion Following LPS instillation, lung mechanics deteriorate within the first 4 days and recover towards day 10. This response is not altered by the lack of T lymphocytes suggesting that T cells play only a minor role for the initiation, propagation or recovery of LPS-induced lung dysfunctions or function of T lymphocytes can be compensated by other immune cells, such as alveolar macrophages.

Oxidative stress is a major component of cellular damage in T cells from patients with systemic lupus erythematosus (SLE) resulting amongst others in the generation of pathogenic Th17 cells. The NRF2/Keap1 pathway is the most important antioxidant system protecting cells from damage due to oxidative stress. Activation of NRF2 therefore seems to represent a putative therapeutic target in SLE, which is nevertheless challenged by several findings suggesting tissue and cell specific differences in the effect of NRF2 expression. This review focusses on the current understanding of oxidative stress in SLE T cells and its pathophysiologic and therapeutic implications.

Background & Aims: Aberrant lymphocyte homing could potentially link inflammatory processes in the intestine and the liver, as distinct hepatobiliary diseases frequently develop as extra-intestinal manifestations in inflammatory bowel disease. In this study, we examined the role of the gut-tropic leukocyte adhesion molecule β7 integrin and its endothelial ligand mucosal addressin cell-adhesion molecule-1 (MAdCAM-1) in immune-mediated hepatitis in mice. Methods: Wild-type (WT) mice, MAdCAM-1-deficient mice, β7 integrin-deficient mice, RAG-2–deficient mice, RAG-2/MAdCAM-1 double-deficient mice, and RAG-2/β7 integrin double-deficient mice were subjected to concanavalin A (ConA)-induced hepatitis. The degree of hepatitis was evaluated by histology, flow cytometry, and expression analysis of inflammatory mediators. The motility of lymphocytes in progressive liver damage was assessed by intravital laser scanning multiphoton microscopy. Results: Ablation of MAdCAM-1 or β7 integrin ameliorated ConA-induced hepatitis in mice. β7 integrin-deficient lymphocytes caused less liver damage than WT lymphocytes in ConA-treated RAG-2–deficient mice. Moreover, WT lymphocytes caused less liver damage in ConA-treated RAG-2/β7 integrin double-deficient mice than in similarly treated RAG-2–deficient mice, indicating that β7 integrin expression contributes significantly to the liver damage mediated by innate immune cells. MAdCAM-1 expression was dependent on β7 integrin expression on adaptive and innate immune cells. Most importantly, lymphocytes in ConA-treated MAdCAM-1-deficient mice displayed more motility and less adhesion in the liver sinusoids in vivo, than lymphocytes in similarly treated WT mice. Conclusions: These data suggest that β7 integrin expression on lymphocytes and innate immune cells contributes to MAdCAM-1 upregulation and liver damage in acute immune-mediated hepatitis, most likely by facilitating lymphocyte/sinusoidal endothelial cell interactions.

Autoimmune diseases are characterized by a failure of tolerance to own body components resulting in tissue damage. Regulatory T cells are gatekeepers of tolerance. This review focusses on the function and pathophysiology of regulatory T cells in the context of autoimmune diseases including rheumatoid and juvenile idiopathic arthritis as well as systemic lupus erythematosus with an overview over current and future therapeutic options to boost Treg function.

Abstract Background Inflammatory effector T cells trigger inflammation despite increased numbers of Treg cells in the synovial joint of patients suffering from juvenile idiopathic arthritis (JIA). The cAMP response element (CREM)α is known to play a major role in regulation of T cells in SLE, colitis, and EAE. However, its role in regulation of effector T cells within the inflammatory joint is unknown. Methods CREM expression was analyzed in synovial fluid cells from oligoarticular JIA patients by flow cytometry. Peripheral blood mononuclear cells were incubated with synovial fluid and analyzed in the presence and absence of CREM using siRNA experiments for T cell phenotypes. To validate the role of CREM in vivo, ovalbumin-induced T cell dependent arthritis experiments were performed. Results CREM is highly expressed in synovial fluid T cells and its expression can be induced by treating healthy control PBMCs with synovial fluid. Specifically, CREM is more abundant in CD161+ subsets, than CD161− subsets, of T cells and contributes to cytokine expression by these cells. Finally, development of ovalbumin-induced experimental arthritis is ameliorated in mice with adoptively transferred CREM−/− T cells. Conclusion In conclusion, our study reveals that beyond its role in SLE T cells CREM also drives an inflammatory phenotype of T cells in JIA.

Abstract Background The term systemic juvenile idiopathic arthritis (sJIA) describes an autoinflammatory condition characterized by arthritis and severe systemic inflammation, which in later stages can transform into interleukin (IL)-17-driven autoimmune arthritis. IL-1 antagonists have been used with good efficacy in the early stages of sJIA. Methods A whole transcriptome analysis of peripheral blood RNA samples was performed in six patients with sJIA and active systemic disease, before initiating treatment with the IL-1β receptor antagonist anakinra, and after induction of inactive disease, compared with a single-sample control cohort of 21 patients in several clinical stages of sJIA activity. Whole transcriptomes were compared longitudinally and interindividually including gene ontology and motif enrichment analysis of differentially expressed genes. Results There were 741 transcripts were identified using a threshold with a p value 2. HLADRB1 and CD74 were identified as the most strongly upregulated genes in inactive compared to active disease; CD177 expression was significantly enhanced in active disease compared to inactive disease. Motif enrichment analysis revealed STAT4, BCL6, and STAT3 as the most prominent transcription factors that were present during active disease. In addition, strong upregulation of the major histocompatability complex II (MHCII) ligand CD74 was found in both active and inactive sJIA compared to healthy controls. Conclusion Using transcription factor motif enrichment, this study identifies novel putative pathways in sJIA (STAT4, BCL6) implicating B cell activation at an earlier stage than predicted in refractory disease. The implication of BCL-6 dependent pathways argues for occurrence of autoimmunity early within the process of sJIA chronification. Transcriptional regulation of HLA-DRB1, a recently described independent genetic risk factor, in combination with its cooperating partner CD74 in patients where sJIA is confirmed, supports pathogenic involvement in alterations in antigen presentation during sJIA.

Background/Aims: IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis and still constitutes one of the most important causes of end-stage renal disease. Abnormal T cell responses may play a role in IgAN pathogenesis. Co-stimulatory molecules such as cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) are important for naive T cells to initiate and terminate immune responses. Single nucleotide polymorphisms (SNPs) in the CTLA4 gene locus are associated with several autoimmune diseases. Methods: We aimed to investigate the occurrence of the SNPs -318C/T, +49A/G and CT60 G/A within the CTLA4 locus in healthy blood donors (n=455) and IgAN patients (n=252) recruited from the recently published STOP-IgAN trial. The presence of these SNPs was then associated with baseline proteinuria in IgAN patients. Results: We observed a significantly increased frequency of the CTLA4 -318C/T genotype in IgAN patients as compared to controls (CC vs. CT+TT: OR 1.65, 95%-CI 1.03-2.65, p=0.035). No significant associations, neither with the +49A/G nor for the CT60 G/A SNP, were detected. However, when we stratified for proteinuria at time of inclusion into the STOP-IgAN trial (1 g/day), we observed significant differences in the frequencies of the CT60 G/A genotype, i.e. a significantly increased risk for higher proteinuria in patients carrying the G allele (OR 2.81, 95%-CI 1.03-7.64, p=0.042). Conclusion: The CTLA4 -318/C/T SNP was associated with an increased risk to develop IgAN, while the CT60 G/A genotype significantly associated with the risk for higher proteinuria suggesting a possible role for CTLA-4 in IgAN.

Introduction: The German PID-NET registry was founded in 2009, serving as the first national registry of patients with primary immunodeficiencies (PID) in Germany. It is part of the European Society for Immunodeficiencies (ESID) registry. The primary purpose of the registry is to gather data on the epidemiology, diagnostic delay, diagnosis, and treatment of PIDs.Methods: Clinical and laboratory data was collected from 2,453 patients from 36 German PID centres in an online registry. Data was analysed with the software Stata® and Excel.Results: The minimum prevalence of PID in Germany is 2.72 per 100,000 inhabitants. Among patients aged 1–25, there was a clear predominance of males. The median age of living patients ranged between 7 and 40 years, depending on the respective PID. Predominantly antibody disorders were the most prevalent group with 57% of all 2,453 PID patients (including 728 CVID patients). A gene defect was identified in 36% of patients. Familial cases were observed in 21% of patients. The age of onset for presenting symptoms ranged from birth to late adulthood (range 0–88 years). Presenting symptoms comprised infections (74%) and immune dysregulation (22%). Ninety-three patients were diagnosed without prior clinical symptoms. Regarding the general and clinical diagnostic delay, no PID had undergone a slight decrease within the last decade. However, both, SCID and hyper IgE- syndrome showed a substantial improvement in shortening the time between onset of symptoms and genetic diagnosis. Regarding treatment, 49% of all patients received immunoglobulin G (IgG) substitution (70%—subcutaneous; 29%—intravenous; 1%—unknown). Three-hundred patients underwent at least one hematopoietic stem cell transplantation (HSCT). Five patients had gene therapy.Conclusion: The German PID-NET registry is a precious tool for physicians, researchers, the pharmaceutical industry, politicians, and ultimately the patients, for whom the outcomes will eventually lead to a more timely diagnosis and better treatment.

Autoimmune and auto-inflammatory diseases in children are causing chronic inflammation, organ damage, and pain. Although several options for treatment are nowadays available a significant number of patients does not respond sufficiently to current therapies. In these diseases inflammatory processes are triggered by numerous exogenous and endogenous factors. There is now increasing evidence that especially a novel family of pro-inflammatory molecules, named alarmins, play a significant role in inflammatory processes underlying these diseases. Alarmins are endogenous proteins released during stress reactions that confer inflammatory signaling via Pattern Recognition Receptors (PRRs), like the Toll-like receptor 4 (TLR4). The most abundant alarmins in juvenile rheumatic diseases belong to the family of pro-inflammatory calcium-binding S100-proteins. In this review we will give a general introduction in S100-biology. We will demonstrate the functional relevance of these proteins in animal models of autoimmune and auto-inflammatory diseases. We will show the expression patterns of S100-alarmins and correlation to disease activity in different forms of juvenile idiopathic arthritis, auto-inflammatory diseases, and systemic autoimmune disorders. Finally, we will discuss the clinical use of S100-alarmins as biomarkers for diagnosis and monitoring of rheumatic diseases in children and will point out potential future therapeutic approaches targeting inflammatory effects mediated by S100-alarmins.

MΦ differentiate from circulating monocytes (Mo). The reduced ability of neonatal Mo to undergo apoptosis after E. coli infection (phagocytosis-induced cell death (PICD)) could contribute to sustained inflammatory processes. The objective of our study was to investigate whether immune metabolism in Mo can be modified to gain access to pro-apoptotic signaling. To this end, we supplemented Mo from neonates and from adults with the branched amino acid leucine. In neonatal Mo, we observed increased energy production via oxidative phosphorylation (Oxphos) after E. coli infection via Seahorse assay. Leucine did not change phagocytic properties. In neonatal Mo, we detected temporal activation of the AKT and mTOR pathways, accompanied with subsequent activation of downstream targets S6 Kinase (S6K) and S6. FACS analyses showed that once mTOR activation was terminated, the level of anti-apoptotic BCL-2 family proteins (BCL-2; BCL-XL) decreased. Release of cytochrome C and cleavage of caspase-3 indicated involvement of the intrinsic apoptotic pathway. Concomitantly, the PICD of neonatal Mo was initiated, as detected by hypodiploid DNA. This process was sensitive to rapamycin and metformin, suggesting a functional link between AKT, mTOR and the control of intrinsic apoptotic signaling. These features were unique to neonatal Mo and could not be observed in adult Mo. Supplementation with leucine therefore could be beneficial to reduce sustained inflammation in septic neonates.

ICER is a CREM splice variant that represses CREM/CREB signalling. Here the authors use human cells and mouse models of various autoimmune diseases to show that ICER is central to pathogenic Th17 cell differentiation in autoimmunity.

Reactive oxygen species (ROS) molecules are implicated in signal transduction pathways and thereby control a range of biological activities. Immune cells are constantly confronted with ROS molecules under both physiologic and pathogenic conditions. Myeloid-derived suppressor cells (MDSCs) are immunosuppressive, immature myeloid cells and serve as major regulators of pathogenic and inflammatory immune responses. In addition to their own release of ROS, MDSCs often arise in oxidative-stress prone environments such as in tumors or during inflammation and infection. This evidently close relationship between MDSCs and ROS prompted us to summarize what is currently known about ROS signaling within MDSCs and to elucidate how MDSCs use ROS to modulate other immune cells. ROS not only activate anti-oxidative pathways but also induce transcriptional programs that regulate the fate and function of MDSCs. Furthermore, MDSCs release ROS molecules as part of a major mechanism to suppress T cell responses. Targeting redox-regulation of MDSCs thus presents a promising approach to cancer therapy and the role of redox-signaling in MDSCs in other disease states such as infection, inflammation and autoimmunity would appear to be well worth investigating.

Arising in inflammatory conditions, myeloid-derived suppressor cells (MDSCs) are constantly confronted with intracellular and extracellular reactive oxygen species molecules and oxidative stress. Generating mice with a constitutive activation of Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) we show a pivotal role of the antioxidant stress defense for development of these immune-modulatory cells. These mice are characterized by a massive increase of splenic CD11b+Gr-1+ cells, which exhibit typical suppressive characteristics of MDSCs. Whole transcriptome analysis revealed Nrf2-dependent activation of cell cycle and metabolic pathways, which resemble pathways in CD11b+Gr-1+ MDSCs expanded by in vivo LPS exposure. Constitutive Nrf2 activation thereby regulates activation and balance between glycolysis and mitochondrial metabolism and hence expansion of highly suppressive MDSCs, which mediate protection in LPS-induced sepsis. Our study establishes Nrf2 as key regulator of MDSCs and acquired tolerance against LPS-induced sepsis.

Dendritic cells (DCs) are crucial for the balance between immune response and tolerance, but the molecular mechanism regulating development, differentiation, and homeostasis are poorly understood. The transcriptional activator CREB is involved in regulating different cells of the innate and adaptive immune system and is a transcriptional regulator of development, survival, activation, or proliferation in macrophages, dendritic cells, B cells, and T cells. To directly examine the role of CREB in the regulation of DCs, the CREB gene was targeted for deletion with a CD11c-cre transgene. The deletion of CREB in CD11c+ cells did not involve any developmental or systemic defects within DC populations. However, CREB deficiency in CD11c+ cells reduced germinal center (GC) B cells in steady state, and immunization with NP-CGG resulted in a reduced formation of GCs, paralleled by the reduced production of IgGs in sera of immunized mice. In conclusion, we demonstrate that CREB expression in CD11c+ cells enhances germinal center responses, most likely by altering DC function, which might have implications for autoimmune diseases that are associated with dysregulated GC responses.

Background: Asthma in childhood has a prevalence of 5–10% in Germany and severe asthma accounts for about 5% in this patient group. Positive predictive values for severe asthma are atopy, a positive family history and sensitizations against inhalative allergens. Alternaria is an important inhalative allergen and sensitization is suspected to correlate with severe and lethal asthma. We investigated the prevalence and impact of Alternaria sensitization in paediatric asthma. Methods: We reviewed paediatric patients with a diagnosis of low-grade, moderate and severe asthma. Data collection included concomitant atopic diseases, sensitization profiles, family history and prior hospitalization for asthma exacerbation. Results: A total of 207 paediatric patients (aged 1–17 years) were included in the study. Overall, 25% had low-grade asthma, 31% moderate and 44% severe asthma and 26% were formerly hospitalized. Alternaria sensitization was the most common in moulds, although without significant correlation with hospitalization and severe asthma. Alternaria sensitization increased with age and was significantly associated with co-sensitization against other moulds, grass pollen and cat epithelia. Allergic rhinitis was significantly correlated with hospitalization, independent of Alternaria sensitization. Conclusions: Alternaria sensitization was common and increased with age. No significant correlation was found between asthma degree, hospitalization rates and sensitization profiles. Alternaria sensitization demonstrated no isolated risk factor for severe asthma and hospitalization.

The cAMP responsive element modulator alpha (CREMα) plays a role in autoimmunity and in particular in systemic lupus erythematosus. CREMα negatively regulates IL-2 transcription and activates IL-17 expression by direct transcriptional mechanisms. To understand the role of CREM in autoimmunity we recently generated a mouse with a transgenic overexpression of CREMα selectively in T cells. This mouse is characterized by enhanced IL-17 and IL-21 expression. We herein dissect the transcriptional mechanisms of enhanced IL-21 transcription in these mice. T cells of CREMα transgenic mice display an enhanced binding of CREMα to the CD3 ζ chain promoter resulting in decreased CD3 ζ chain expression. This is accompanied by a decreased excitation threshold and enhanced Ca2+ influx resulting in Il-21 promoter activation upon T cell stimulation. Furthermore, CREMα directly binds to a CRE half-site within the Il-21 promoter which also results in enhanced promoter activity shown by promoter reporter assays. IL-21 transcription is critical for IL-17 generation in these mice, since IL-21 receptor blockade downregulates IL-17 transcription to wildtype levels. Finally, this is of functional relevance since CREMα transgenic mice display enhanced disease activity in dextrane sodium sulfate induced colitis accompanied by higher local IL-21 expression.Thus we describe 2 novel mechanisms of CREMα dependent IL-21 transcription. Since T cells of SLE patients are characterized by enhanced IL-21 transcription this might also be of functional relevance in humans.

Background: Allergic bronchopulmonary aspergillosis (ABPA) is a severe complication in patients with cystic fibrosis (CF), resulting in deterioration of lung function and impairment of overall prognosis. Standard therapy consists of high dosage, long-term corticosteroid treatment. This carries the risk of serious side effects such as immune suppression, diabetes and osteoporosis. Antifungal drugs such as itraconazole may cause interactions with other drugs and drug levels need to be monitored. Omalizumab treatment has been tried in several case studies. Methods: This was a retrospective study of six patients (four female, two male, age 4–33 years old) with CF and ABPA treated with omalizumab within an observation period of 7.5 years. Results: All patients showed clinical and laboratory stability or even an improvement within the treatment and post-treatment observation period, although omalizumab therapy was less effective in patients with progressed lung disease and long-term ABPA. Side effects of systemic steroids were reduced. Conclusion: Omalizumab has the potential to be an additional and solitary treatment option in patients with CF and ABPA. Early onset treatment may be beneficial and patients with early stage of lung disease seem to benefit more.