Unravelling the clinical heterogeneity of undefined recurrent fever over time in the European registries on Autoinflammation.

BACKGROUND: Systemic autoinflammatory disorders (SAIDs) represent a growing spectrum of diseases characterized by dysregulation of the innate immune system. The most common pediatric autoinflammatory fever syndrome, Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA), has well defined clinical diagnostic criteria, but there is a subset of patients who do not meet these criteria and are classified as undefined autoinflammatory diseases (uAID). This project, endorsed by PRES, supported by the EMERGE fellowship program, aimed to analyze the evolution of symptoms in recurrent fevers without molecular diagnosis in the context of undifferentiated AIDs, focusing on PFAPA and syndrome of undifferentiated recurrent fever (SURF), using data from European AID registries. METHODS: Data of patients with PFAPA, SURF and uSAID were collected from 3 registries including detailed epidemiological, demographic and clinical data, results of the genetic testing and additional laboratory investigations with retrospective application of the modified Marshall and PRINTO/Eurofever classification criteria on the cohort of PFAPA patients and preliminary SURF criteria on uSAID/SURF patients. RESULTS: Clinical presentation of PFAPA is variable and some patients did not fit the conventional PFAPA criteria and exhibit different symptoms. Some patients did not meet the criteria for either PFAPA or SURF, highlighting the heterogeneity within these groups. The study also explored potential overlaps between PFAPA and SURF/uAID, revealing that some patients exhibited symptoms characteristic of both conditions, emphasizing the need for more precise classification criteria. CONCLUSIONS: Patients with recurrent fevers without molecular diagnoses represent a clinically heterogeneous group. Improved classification criteria are needed for both PFAPA and SURF/uAID to accurately identify and manage these patients, ultimately improving clinical outcomes.

[Protocols in pediatric rheumatology (PROKIND): treat-to-target in polyarticular juvenile idiopathic arthritis]. / Protokolle in der Kinderrheumatologie (PROKIND): Treat-to-Target bei polyartikulärer juveniler idiopathischer Arthritis.

BACKGROUND: The aims of the PROKIND protocols are improvement and harmonization of the diagnostics, monitoring, treatment decision and prognosis. MATERIAL AND METHODS: This article reports the results of a prospective treat-to-target observational study of patients with polyarticular juvenile idiopathic arthritis (JIA) during the first year of treatment. Disease activity was assessed with the 10-joint juvenile arthritis disease activity score (JADAS-10), functional limitation with the childhood health assessment questionnaire disability index (CHAQ-DI) and with information on overall well-being, on pain, on fatigue and on global estimation of disease activity. RESULTS: Overall, 129 patients with polyarticular JIA (rheumatoid factor, RF, positive (+) polyarthritis n = 22, RF negative (-) polyarthritis n = 133 from 23 pediatric rheumatology institutions in Germany and Austria were recruited. Patients with initial treatment with methotrexate formed cohort 1, patients with additional repeated intravenous corticosteroid pulse therapy formed cohort 2 and patients with concomitant intra-articular corticosteroid administration in at least 5 joints formed cohort 3. The mean JADAS10 showed a decrease in disease activity from 16.4 ± 6.1 to 2.8 ± 3.6 and the decrease in the CHAQ-DI from 1.0 ± 0.8 to 0.3 ± 0.5 showed the improvement in functional capacity. Similarly, improvements in quality of life, pain and fatigue were demonstrable. A JADAS inactive disease was achieved by 18.1% at month 3, 47.7% at month 6 and 66.7% at month 12. In cohort 1 a JADAS remission was achieved by 72.4%, by 50% in cohort 2 and by 69.2% in cohort 3. An escalation to treatment with biologics was necessary in 38% of patients in cohort 1, 60% in cohort 2 and 46% in cohort 3. CONCLUSION: Using a treat-to-target approach a dramatic improvement in disease activity, functional capacity and quality of life in polyarticular JIA could be achieved. Even after 12 months an inactive disease was achieved in the majority of cases.

Phagocytic cell death leads to enhanced release of pro-inflammatory S100A12 in familial Mediterranean fever.

BACKGROUND: Familial Mediterranean fever (FMF) is a prototypical autoinflammatory syndrome associated with phagocytic cell activation. Pyrin mutations are the genetic basis of this disease, and its expression has been shown in monocytes, granulocytes, dendritic cells, and synovial fibroblasts. Pyrin functions as a cytosolic pattern recognition receptor and forms a distinct pyrin inflammasome. The phagocyte-specific protein S100A12 is predominantly expressed in granulocytes and belongs to the group of damage associated molecular patterns (DAMP). S100A12 can be detected at massively elevated levels in the serum of FMF patients, even in clinically inactive disease. Whether this is crucial for FMF pathogenesis is as yet unknown, and we therefore investigated the mechanisms of S100A12 release from granulocytes of FMF patients presenting clinically inactive. RESULTS: We demonstrate that FMF neutrophils from patients in clinical inactive disease possess an intrinsic activity leading to cell death even in exogenously unstimulated neutrophils. Cell death resembles NETosis and is dependent on ROS and pore forming protein gasdermin D (GSDMD), as inhibitors for both are capable of completely block cell death and S100A12 release. When pyrin-activator TcdA (Clostridium difficile toxin A) is used to stimulate, neutrophilic cell death and S100A12 release are significantly enhanced in neutrophils from FMF patients compared to neutrophils from HC. CONCLUSIONS: We are able to demonstrate that activation threshold of neutrophils from inactive FMF patients is decreased, most likely by pre-activated pyrin. FMF neutrophils present with intrinsically higher ROS production, when cultured ex vivo. This higher baseline ROS activity leads to increased GSDMD cleavage and subsequent release of, e.g., S100A12, and to increased cell death with features of NETosis and pyroptosis. We show for the first time that cell death pathways in neutrophils of inactive FMF patients are easily triggered and lead to ROS- and GSDMD-dependent activation mechanisms and possibly pathology. This could be therapeutically addressed by blocking ROS or GSDMD cleavage to decrease inflammatory outbreaks when becoming highly active.

Breaking down the fences among registries on autoinflammatory diseases: the E-Merge project.

BACKGROUND: Among the various numbers of different autoinflammatory diseases (AIDs), the absolute majority of them remains rare, with a single representative in large populations. This project, endorsed by PRES, supported by the EMERGE fellowship program, and performed in line with the Metadata registry for the ERN RITA (MeRITA), has the objective of performing a data synchronization attempt of the most relevant research questions regarding clinical features, diagnostic strategies, and optimal management of autoinflammatory diseases. RESULTS: An analysis of three large European registries: Eurofever, JIR-cohort and AID-Net, with a total coverage of 7825 patients from 278 participating centers from different countries, was performed in the context of epidemiological and clinical data merging. The data collected and evaluated in the registries does not cover only pediatric patients, but also adults with newly diagnosed AIDs. General aspects of the existing epidemiological data have been discussed in the context of patient global distribution, potential diagnostic delays, access to genetic testing, and the availability of the treatment. CONCLUSIONS: In general, the results indicate a great potential for upcoming collaborative work using existing data in cohorts that enhance the quality of medical care performed for patients with autoinflammatory diseases.

Refining the dermatological spectrum in primary immunodeficiency: mucosa-associated lymphoid tissue lymphoma translocation protein 1 deficiency mimicking Netherton/Omenn syndromes.

The proteinase mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1), which forms part of the caspase recruitment domain-containing protein 11-B-cell lymphoma 10-MALT1 signalosome complex, plays a direct role in nuclear factor kappa B activation. Here, we describe the case of a female infant with severe immune dysregulation leading to recurrent systemic infections, failure to thrive and severe crises of ichthyosiform erythroderma with high levels of serum IgE. Hence, initial symptoms indicated Netherton syndrome or Omenn syndrome. Surprisingly, sequence analyses of SPINK5 and RAG1/RAG2, respectively, excluded these diseases. During the hospital stay the patient's health deteriorated, despite intensive care therapy, and she died. In order to delineate the diagnosis, whole-exome sequencing was performed. Two compound heterozygous mutations in MALT1 were found and verified by Sanger sequencing (exon 2 c.245T>C, exon 2 c.310dup), which led to a MALT1 deficiency at the protein level. Based on these results, an immunological analysis was performed, as was immunofluorescence staining of key skin proteins, to confirm a diagnosis of MALT1 deficiency. This case report provides a closer description of the clinical and histological skin phenotype of MALT1 deficiency, and we conclude that MALT1 deficiency must be considered a possible differential diagnosis of Netherton and Omenn syndromes. What's already known about this topic? Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) deficiency is a combined immunodeficiency. MALT1 is part of the caspase recruitment domain-containing protein 11-B-cell lymphoma 10-MALT1 signalosome complex, which is essential for nuclear factor kappa B activation. Current publications describe a phenotype of recurrent systemic infections; only in a few cases has an inflammatory involvement of the integument been described. What does this study add? A closer description of the cutaneous phenotype of MALT1 deficiency in a patient with two novel MALT1 mutations. Immune mapping of follicular epidermis shows lympho-epithelial Kazal-type-related inhibitor is reduced in MALT1 deficiency and absent on interfollicular staining. Clinically, MALT1 deficiency mimics Netherton syndrome and Omenn syndrome, and should be considered a differential diagnosis.

Electro-mechanical dysfunction in long QT syndrome: Role for arrhythmogenic risk prediction and modulation by sex and sex hormones.

Long QT syndrome (LQTS) is a congenital arrhythmogenic channelopathy characterized by impaired cardiac repolarization. Increasing evidence supports the notion that LQTS is not purely an "electrical" disease but rather an "electro-mechanical" disease with regionally heterogeneously impaired electrical and mechanical cardiac function. In the first part, this article reviews current knowledge on electro-mechanical (dys)function in LQTS, clinical consequences of the observed electro-mechanical dysfunction, and potential underlying mechanisms. Since several novel imaging techniques - Strain Echocardiography (SE) and Magnetic Resonance Tissue Phase Mapping (TPM) - are applied in clinical and experimental settings to assess the (regional) mechanical function, advantages of these non-invasive techniques and their feasibility in the clinical routine are particularly highlighted. The second part provides novel insights into sex differences and sex hormone effects on electro-mechanical cardiac function in a transgenic LQT2 rabbit model. Here we demonstrate that female LQT2 rabbits exhibit a prolonged time to diastolic peak - as marker for contraction duration and early relaxation - compared to males. Chronic estradiol-treatment enhances these differences in time to diastolic peak even more and additionally increases the risk for ventricular arrhythmia. Importantly, time to diastolic peak is particularly prolonged in rabbits exhibiting ventricular arrhythmia - regardless of hormone treatment - contrasting with a lack of differences in QT duration between symptomatic and asymptomatic LQT2 rabbits. This indicates the potential added value of the assessment of mechanical dysfunction in future risk stratification of LQTS patients.

[Translational research in pediatric rheumatology. Current research approaches to the innate immune system]. / Translationale Forschung in der pädiatrischen Rheumatologie. Aktuelle Forschungsansätze zum angeborenen Immunsystem.

Translational research aims at closely linking basic research and clinical observations so that important mechanistic insights identified in one field should trigger progress in the other. Particularly in the field of pediatric rheumatology this approach has significantly improved the understanding and therapy of several diseases in recent years. One focus of our research in this respect is on the structure, release mechanisms and function of damage associated molecular patterns (DAMP), particularly S100 proteins. Due to their huge potential as inflammation biomarkers for more specific diagnostics these proteins are of particular clinical interest. Overactivated cells of the innate immune system play a crucial role in the development of rheumatic diseases. Innate mechanisms, such as the generation of neutrophil extracellular traps (NETosis) were linked to the pathogenesis of inflammatory diseases, such as systemic lupus erythematosus and rheumatoid arthritis. Furthermore, it became increasingly more evident that various excessive sterile inflammatory mechanisms and reactions significantly contribute to an activation of adaptive immune responses and thus to the development of autoimmunity. Studying such potentially DAMP-dependent pathways at the interface between innate and adaptive immunity can provide a better understanding of autoinflammatory conditions in pediatric rheumatology and to identify novel targets for optimization of therapy.

Elevated calprotectin levels reveal bowel inflammation in spondyloarthritis.

INTRODUCTION: Microscopic bowel inflammation is present in up to 50% of patients with spondyloarthritis (SpA) and is associated with more severe disease. Currently no reliable biomarkers exist to identify patients at risk. Calprotectin is a sensitive marker of neutrophilic inflammation, measurable in serum and stool. OBJECTIVES: To assess whether serum and faecal calprotectin in addition to C-reactive protein (CRP) can be used to identify patients with SpA at risk of microscopic bowel inflammation. METHODS: Serum calprotectin and CRP were measured in 125 patients with SpA. In 44 of these patients, faecal samples were available for calprotectin measurement. All 125 patients underwent an ileocolonoscopy to assess the presence of microscopic bowel inflammation. RESULTS: Microscopic bowel inflammation was present in 53 (42.4%) patients with SpA. Elevated serum calprotectin and CRP were independently associated with microscopic bowel inflammation. Faecal calprotectin was also significantly higher in patients with microscopic bowel inflammation. Patients with CRP and serum calprotectin elevated had a frequency of bowel inflammation of 64% vs 25% in patients with low levels of both. When either CRP or serum calprotectin was elevated, the risk was intermediate (40%) and measuring faecal calprotectin provided further differentiation. Hence we suggest a screening approach where initially serum calprotectin and CRP are assessed and, if necessary, faecal calprotectin. The model using this scenario provided an area under the ROC curve of 74.4% for detection of bowel inflammation. CONCLUSIONS: Calprotectin measurements in stool and serum, in addition to CRP, may provide a promising strategy to identify patients with SpA at risk of bowel inflammation and could play a role in overall patient stratification.

Activated STING in a vascular and pulmonary syndrome.

BACKGROUND: The study of autoinflammatory diseases has uncovered mechanisms underlying cytokine dysregulation and inflammation. METHODS: We analyzed the DNA of an index patient with early-onset systemic inflammation, cutaneous vasculopathy, and pulmonary inflammation. We sequenced a candidate gene, TMEM173, encoding the stimulator of interferon genes (STING), in this patient and in five unrelated children with similar clinical phenotypes. Four children were evaluated clinically and immunologically. With the STING ligand cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), we stimulated peripheral-blood mononuclear cells and fibroblasts from patients and controls, as well as commercially obtained endothelial cells, and then assayed transcription of IFNB1, the gene encoding interferon-ß, in the stimulated cells. We analyzed IFNB1 reporter levels in HEK293T cells cotransfected with mutant or nonmutant STING constructs. Mutant STING leads to increased phosphorylation of signal transducer and activator of transcription 1 (STAT1), so we tested the effect of Janus kinase (JAK) inhibitors on STAT1 phosphorylation in lymphocytes from the affected children and controls. RESULTS: We identified three mutations in exon 5 of TMEM173 in the six patients. Elevated transcription of IFNB1 and other gene targets of STING in peripheral-blood mononuclear cells from the patients indicated constitutive activation of the pathway that cannot be further up-regulated with stimulation. On stimulation with cGAMP, fibroblasts from the patients showed increased transcription of IFNB1 but not of the genes encoding interleukin-1 (IL1), interleukin-6 (IL6), or tumor necrosis factor (TNF). HEK293T cells transfected with mutant constructs show elevated IFNB1 reporter levels. STING is expressed in endothelial cells, and exposure of these cells to cGAMP resulted in endothelial activation and apoptosis. Constitutive up-regulation of phosphorylated STAT1 in patients' lymphocytes was reduced by JAK inhibitors. CONCLUSIONS: STING-associated vasculopathy with onset in infancy (SAVI) is an autoinflammatory disease caused by gain-of-function mutations in TMEM173. (Funded by the Intramural Research Program of the National Institute of Arthritis and Musculoskeletal and Skin Diseases; ClinicalTrials.gov number, NCT00059748.).

S100A12 and hBD2 correlate with the composition of the fecal microflora in ELBW infants and expansion of E. coli is associated with NEC.

OBJECTIVE: To describe the development of the gut microbiota in extremely low birth weight (ELBW) infants with and without necrotizing enterocolitis (NEC) between April 2008 and December 2009, fecal microflora was prospectively analyzed in fecal samples of all ELBW infants using real-time PCR assays. In addition, fecal inflammatory were measured. RESULTS: Fecal microflora established early in ELBW infants and microbiota composition remained stable over the first 28 days of life except for the prevalence of C. difficile which decreased with decreasing antibiotic use. Infants who subsequently developed NEC had an increase of total bacterial count (9.8-fold) 24 h prior to clinical symptoms mainly due to the expansion of E. coli species (21.6-fold), whereas microbiota composition did not differ from healthy ELBW infants five days before onset of NEC. Importantly, S100A12 and hBD2 positively correlated with the total and E. coli bacterial CFU/g feces (r (2) 0.4 and 0.64, resp.). CONCLUSIONS: In summary, we found evidence for a disturbed homeostasis between the intestinal microbiome and host immunity in ELBW infants with NEC. Moreover, S100A12 and hBD2 correlate with the fecal microbiota thus linking the intestinal innate immune response to the bacterial colonization thus possibly providing a diagnostic tool in the future.

Hypertensive heart disease: MR tissue phase mapping reveals altered left ventricular rotation and regional myocardial long-axis velocities.

OBJECTIVES: The aim of this study was the evaluation of left ventricular (LV) segmental 3D velocities in patients with hypertensive heart disease using magnetic resonance (MR) tissue phase mapping (TPM). METHODS: LV radial, long-axis and rotational myocardial velocities were assessed by TPM in patients with LV hypertrophy and preserved EF (n = 18, age = 53 ± 12 years) and volunteers (n = 20, age = 51 ± 4 years). Systolic and diastolic peak and time-to-peak velocities were mapped onto a 16-segment LV model. 3D myocardial motion was displayed on an extended visualisation model. Correlation coefficients were calculated to investigate differences in regional dynamics. RESULTS: Patients revealed diastolic dysfunction as expressed by decreased peak long-axis velocities in all (except apical) segments (basal, P ≤ 0.01; two midventricular segments, P = 0.02, P = 0.03). During systole, hypertrophy was associated with heterogeneous behaviour for long-axis velocities including an increase in anteroseptal apical and midventricular regions (P = 0.001), a reduction in mid-inferior segments (P = 0.03) and enhanced septal velocities (P < 0.05). Segmental correlation analysis revealed altered dynamics of LV base rotation and increased dyssynchrony of lateral long-axis motion. CONCLUSIONS: Patients with hypertensive heart disease demonstrated alterations in systolic long-axis motion, basal rotation and dyssynchrony. Longitudinal studies are needed to investigate the value of regional wall motion abnormalities regarding disease progression and outcome.

Monitoring disease activity by stool analyses: from occult blood to molecular markers of intestinal inflammation and damage.

It is a common experience that gastrointestinal symptoms urge us to differentiate inflammatory bowel disease (IBD) from functional disorders. Furthermore, in patients with proven IBD the disease activity has to be accurately monitored. Faecal markers of neutrophil influx into the mucosa are promising indicators of intestinal inflammation. Some neutrophil-derived proteins may be linked to the pathogenesis of IBD due to their functions as damage-associated molecular pattern molecules (DAMPs). Phagocyte-specific DAMPs of the S100 family are released from neutrophils or monocytes, followed by pro-inflammatory activation of pattern recognition receptors. The complex of S100A8/S100A9 was termed "calprotectin" and has been in use as a faecal marker for 10 years. More recently, faecal S100A12 has been reported to be an even more accurate faecal marker of inflammation. We review the biology of this novel group of molecules which can be used as surrogate markers directly linked to the molecular mechanisms of gut inflammation.

Phagocyte-specific S100 proteins are released from affected mucosa and promote immune responses during inflammatory bowel disease.

Phagocyte-derived S100 proteins are endogenous activators of innate immune responses. S100A12 binds to the receptor for advanced glycation end-products, while complexes of S100A8/S100A9 (myeloid-related proteins, MRP8/14; calprotectin) are ligands of toll-like receptor 4. These S100 proteins can be detected in stool. In the present study we analyse the release of S100A12 and MRP8/14 from intestinal tissue. Specimens from patients with Crohn's disease (CD; n = 30), ulcerative colitis (UC; n = 30), irritable bowel syndrome (IBS; n = 30) or without inflammation (n = 30) were obtained during endoscopy. After 24 h culture, S100A12 and MRP8/14 were analysed in supernatants. Endoscopic, histological, laboratory and clinical disease activity measures were documented. We found an increased spontaneous release of S100A12 from tissue in inflammatory bowel disease (IBD). The release of S100A12 into the supernatants was 28-fold enhanced in inflamed tissue when compared to non-inflamed tissue (mean 46.9 vs. 1.7 ng/ml, p < 0.0001). In active CD, release of S100A12 and MRP8/14 was strongly dependent on localization, with little release from sites of active ileal inflammation compared to colonic inflammation. This difference was more pronounced for S100A12 than for MRP8/14. S100A12 and MRP8/14 provoked up-regulation of adhesion molecules and chemokines on human intestinal microvascular endothelial cells (HIMECs) isolated from normal colonic tissue. The direct release of phagocyte-derived S100 proteins from inflamed tissues may reflect secretion from infiltrating neutrophils (S100A12) and also monocytes or epithelial cells (MRP8/14). Via activation of pattern recognition receptors, these proteins promote inflammation in intestinal tissue. The enhanced mucosal release can explain the correlation of fecal markers with disease activity in IBD.

Faecal S100A12 as a non-invasive marker distinguishing inflammatory bowel disease from irritable bowel syndrome.

OBJECTIVE: S100A12 is a pro-inflammatory protein that is secreted by granulocytes. S100A12 serum levels increase during inflammatory bowel disease (IBD). We performed the first study analysing faecal S100A12 in adults with signs of intestinal inflammation. METHODS: Faecal S100A12 was determined by ELISA in faecal specimens of 171 consecutive patients and 24 healthy controls. Patients either suffered from infectious gastroenteritis confirmed by stool analysis (65 bacterial, 23 viral) or underwent endoscopic and histological investigation (32 with Crohn's disease, 27 with ulcerative colitis, and 24 with irritable bowel syndrome; IBS). Intestinal S100A12 expression was analysed in biopsies obtained from all patients. Faecal calprotectin was used as an additional non-invasive surrogate marker. RESULTS: Faecal S100A12 was significantly higher in patients with active IBD (2.45 +/- 1.15 mg/kg) compared with healthy controls (0.006 +/- 0.03 mg/kg; p<0.001) or patients with IBS (0.05 +/- 0.11 mg/kg; p<0.001). Faecal S100A12 distinguished active IBD from healthy controls with a sensitivity of 86% and a specificity of 100%. We also found excellent sensitivity of 86% and specificity of 96% for distinguishing IBD from IBS. Faecal S100A12 was also elevated in bacterial enteritis but not in viral gastroenteritis. Faecal S100A12 correlated better with intestinal inflammation than faecal calprotectin or other biomarkers. CONCLUSIONS: Faecal S100A12 is a novel non-invasive marker distinguishing IBD from IBS or healthy individuals with a high sensitivity and specificity. Furthermore, S100A12 reflects inflammatory activity of chronic IBD. As a marker for neutrophil activation, faecal S100A12 may significantly improve our arsenal of non-invasive biomarkers of intestinal inflammation.

Elevated serum levels of calcium-binding S100 proteins A8 and A9 reflect disease activity and abnormal differentiation of keratinocytes in psoriasis.

BACKGROUND: The expression of calcium-binding S100 molecules organized within the epidermal differentiation complex on chromosome 1q21 is disturbed in hyperproliferative skin diseases such as psoriasis. OBJECTIVES: We studied whether serum levels of S100 proteins A8 (S100A8) and A9 (S100A9) are elevated in psoriasis, correlated their amounts with disease activity and identified potential cellular sources. METHODS: Serum obtained from psoriasis patients or from healthy individuals was studied for S100A8 and S100A9 levels by enzyme-linked immunosorbent assay. Data were correlated to disease activity as reflected by the Psoriasis Area and Severity Index (PASI). Cellular sources of S100A8 and S100A9 were identified by in situ hybridization and immunohistochemistry of lesional psoriatic and nonlesional, nonpsoriatic skin. RESULTS: A significant increase of S100A8/S100A9 serum levels was found in patients with psoriasis compared with healthy controls. Grading the patients into two groups of severity, individuals with a PASI of <15 showed serum levels of 705+/-120 ng mL-1 (mean+/-SEM, n=18), those with a PASI of >or=15 showed levels of 1315+/-150 ng mL-1 (n=32) while controls presented with 365+/-50 ng mL-1. Performing in situ hybridization of lesional psoriatic skin we detected a dramatic induction of both S100A8 and S100A9 mRNA and protein primarily in the suprabasal layers of the epidermis while expression was negligible in nonlesional, nonpsoriatic interfollicular epidermis. CONCLUSIONS: Our data demonstrate that hyperproliferation and abnormal differentiation of psoriatic skin is associated with a massive upregulation and secretion of S100A8 and S100A9, suggesting not only a prominent role of these molecules during intracellular calcium-dependent signalling but also implying distinct extracellular functions.

Myeloid related proteins MRP8/MRP14 may predict disease flares in juvenile idiopathic arthritis.

OBJECTIVE: An unsolved problem in juvenile idiopathic arthritis (JIA) is to identify patients at special risk for relapse. It is important to adjust anti-inflammatory and immunosuppressive therapy to the children's actual disease activity especially in times of remission. Our aim was to analyze if the serum levels of MRP8/MRP14 are reliable predictive markers for the risk of relapse in clinically inactive juvenile idiopathic arthritis. METHODS: Serum concentrations of MRP8/MRP14 were determined by ELISA and correlated with laboratory and clinical parameters for disease activity in patients with JIA. 29 patients with changing disease activity were followed up for a mean time of 2.9 years. Two groups of patients--one before relapse (mean 3.7 months) but without clinical signs of disease reactivation, and one in remission for 12 further months--were compared. RESULTS: MRP8/MRP14 serum levels in patients before relapses were significantly higher than the levels in patients in stable remission for one year (662 ng/ml versus 395 ng/ml; p < 0.05). Using a cut-off for MRP8/MRP14 of 450 ng/ml the likelihood ratio for relapse was 3.7 (positive predictive value 80%), while no differences were found for C-reactive protein and erythrocyte sedimentation rate between the two groups. CONCLUSION: MRP8/MRP14 correlate with individual disease activity in patients with JIA. Our data suggest that local disease activity may be present even months before flares become clinically apparent. Serum levels of MRP8/MRP14 can give a hint as to clinically occult disease activity, in this way helping to adjust therapy in times of low disease activity.

Methotrexate treatment in juvenile idiopathic arthritis: when is the right time to stop?

OBJECTIVES: To investigate whether prolonged methotrexate (MTX) treatment after induction of remission influences the subsequent duration of remission in patients with juvenile idiopathic arthritis (JIA), and to analyse the usefulness of myeloid related proteins 8 and 14 (MRP8/MRP14) as predictive markers for the stability of remission at the time when MTX is withdrawn. METHODS: Twenty five patients with oligoarticular and polyarticular JIA who received MTX to induce remission were followed up. MTX treatment was stopped after a mean of 3.8 months (group 1) or 12.6 months (group 2) after remission was documented. Differences in the number of relapses between these groups were looked for. Additionally, MRP8/MRP14 were analysed by ELISA in 22 patients. RESULTS: No difference was found in the number of relapses between patients with prolonged or early discontinued MTX treatment. Patients who were in stable remission had significantly lower MRP levels when MTX was discontinued than patients with relapses. With a cut off point for MRP8/MRP14 at 250 ng/ml, sensitivity and specificity were 100% and 70%, respectively. CONCLUSION: Longer duration of MTX treatment after induction of remission does not generally improve the status of remission in patients with JIA. Residual synovial inflammation seems to influence the rate of relapses after discontinuation of MTX treatment. MRP8/MRP14 indicate residual activity even in the absence of other laboratory or clinical signs of continuing inflammation. Normal serum concentrations of MRP8/MRP14 in clinical inactive arthritis may help to identify patients in whom MTX can be safely withdrawn after remission is achieved.

Expression of S100A12 (EN-RAGE) in cystic fibrosis.

BACKGROUND: Chronic airway inflammation and recurrent infections are a core phenomenon in cystic fibrosis (CF). Diagnosing acute infectious exacerbations is difficult in the presence of chronic inflammatory processes. S100A12 exhibits proinflammatory functions via interaction with the multiligand receptor for advanced glycation end products. Blocking this interaction inhibits inflammatory processes in mice. METHODS: The expression of S100A12 in lung specimens of patients with end stage lung disease of CF was investigated, and S100A12 levels in the serum of patients with acute infectious exacerbations of CF were measured. RESULTS: Immunohistochemical studies of CF lung biopsy specimens revealed a significant expression of S100A12 by infiltrating neutrophils. High S100A12 levels were found in the sputum of patients with CF, and serum levels of S100A12 during acute infectious exacerbations were significantly increased compared with healthy controls (median 225 ng/ml v 46 ng/ml). After treatment with intravenous antibiotics the mean S100A12 level decreased significantly. There was also a significant difference between S100A12 levels in patients with acute infectious exacerbations and 18 outpatients without exacerbations (median 225 ng/ml v 105 ng/ml). CONCLUSIONS: S100A12 is extensively expressed at local sites of inflammation in CF. It is a serum marker for acute infectious exacerbations. High local expression of S100A12 suggests that this protein has a proinflammatory role during airway inflammation and may serve as a novel target for anti-inflammatory treatments.