Gain-of-function CEBPE mutation causes noncanonical autoinflammatory inflammasomopathy.

BACKGROUND: CCAAT enhancer-binding protein epsilon (C/EBPε) is a transcription factor involved in late myeloid lineage differentiation and cellular function. The only previously known disorder linked to C/EBPε is autosomal recessive neutrophil-specific granule deficiency leading to severely impaired neutrophil function and early mortality. OBJECTIVE: The aim of this study was to molecularly characterize the effects of C/EBPε transcription factor Arg219His mutation identified in a Finnish family with previously genetically uncharacterized autoinflammatory and immunodeficiency syndrome. METHODS: Genetic analysis, proteomics, genome-wide transcriptional profiling by means of RNA-sequencing, chromatin immunoprecipitation (ChIP) sequencing, and assessment of the inflammasome function of primary macrophages were performed. RESULTS: Studies revealed a novel mechanism of genome-wide gain-of-function that dysregulated transcription of 464 genes. Mechanisms involved dysregulated noncanonical inflammasome activation caused by decreased association with transcriptional repressors, leading to increased chromatin occupancy and considerable changes in transcriptional activity, including increased expression of NLR family, pyrin domain-containing 3 protein (NLRP3) and constitutively expressed caspase-5 in macrophages. CONCLUSION: We describe a novel autoinflammatory disease with defective neutrophil function caused by a homozygous Arg219His mutation in the transcription factor C/EBPε. Mutated C/EBPε acts as a regulator of both the inflammasome and interferome, and the Arg219His mutation causes the first human monogenic neomorphic and noncanonical inflammasomopathy/immunodeficiency. The mechanism, including widely dysregulated transcription, is likely not unique for C/EBPε. Similar multiomics approaches should also be used in studying other transcription factor-associated diseases.

The evolving treatment of ANCA-associated vasculitides.

Prevention of organ damage and maintenance of long-term remission are the principal goals for treatment of ANCA-associated vasculitides. This can be accomplished by early diagnosis and swift initiation of remission-inducing agents. Outcome has improved but relapses and glucocorticoid- and cyclophosphamide-related toxicity are still major concerns. For remission induction in generalized disease a combination of glucocorticoids and cyclophosphamide or rituximab is used. Rituximab is suitable especially for younger patients with fertility concerns and when cyclophosphamide avoidance otherwise is desirable. In the treatment of relapses and refractory disease, rituximab has proved effective. As maintenance treatment rituximab prevents relapses more effectively than azathioprine.

[IgG4-related disease--a common denominator of many conditions previously regarded as being confined to a single organ]. / IgG4:ään liittyvä i sairaus--monen näennäsesti yhden elimen tautitilan yhteinen nimittäjä.

IgG4-related disease is a newly recognized systemic condition characterized by high serum IgG4 levels and an inflammatory reaction rich in IgG4-positive plasma cells associated with fibrosis and obliterative phlebitis. It predominantly affects middle-aged or elderly males and was first described as autoimmune pancreatitis. The disease may also involve the hepatobiliary tract, salivary glands, orbit, lymph nodes, and the lungs, aorta, retroperitoneum, skin, nervous system, kidneys and thyroid gland. It may mimic infections, malignancies, and other immune-mediated conditions. Histopathology and immunohistochemistry form the basis of the diagnosis. Glucocorticoids are usually effective but relapses occur commonly.

[Systemic sclerosis]. / Systeeminen skleroosi.

Systemic sclerosis (scleroderma) is a rare connective tissue disease characterized by vasculopathy and immune dysfunction, leading to fibrosis with damage of multiple organs. Two major clinical subtypes are the diffuse and limited forms. The combination of Raynaud's phenomenon, puffy fingers and positive antinuclear antibodies are red flag features that should alert the clinician to the presence of very early systemic sclerosis, which can be treated with vasodilator, antithrombotic, and immunosuppressive drugs. Progress has been made even in the management of the most severe manifestations, including interstitial lung disease, pulmonary artery hypertension and scleroderma renal crisis.

Injection-site reactions upon Kineret (anakinra) administration: experiences and explanations.

Anakinra (Kineret), a recombinant form of human interleukin-1 (IL-1) receptor antagonist, is approved for the treatment of rheumatoid arthritis (RA) in combination with methotrexate. Kineret is self-administered by daily subcutaneous injections in patients with active RA. The mechanism of action of anakinra is to competitively inhibit the local inflammatory effects of IL-1. Kineret is generally safe and well tolerated and the only major treatment-related side effects that appear are skin reactions at the injection site. Due to the relatively short half-life of anakinra, daily injection of the drug is required. This, in combination with the comparably high rates of injection-site reactions (ISRs) associated with the drug, can become a problem for the patient. The present review summarises published data concerning ISRs associated with Kineret and provides some explanations as to their cause. The objective is also to present some clinical experiences of how the ISRs can be managed.

Differential cytokine secretion results from p65 and c-Rel NF-κB subunit signaling in peripheral blood mononuclear cells of TNF receptor-associated periodic syndrome patients.

Tumor necrosis factor receptor-associated periodic syndrome (TRAPS) is an autosomal dominant autoinflammatory condition caused by mutations in the TNFRSF1A gene which encodes the tumor necrosis factor (TNF) receptor, TNFR1. We investigated the effect of three high penetrance and three low penetrance TNFRSF1A mutations upon NF-κB transcription factor family subunit activity, and the resulting impact upon secretion of 25 different cytokines. Whilst certain mutations resulted in elevated NF-κB p65 subunit activity, others instead resulted in elevated c-Rel subunit activity. Interestingly, high p65 activity was associated with elevated IL-8 secretion, whereas high c-Rel activity increased IL-1ß and IL-12 secretion. In conclusion, while all six TNFRSF1A mutations showed enhanced NF-κB activity, different mutations stimulated distinct NF-κB family subunit activities, and this in turn resulted in the generation of unique cytokine secretory profiles.

[Large-vessel vasculitides]. / Suurten suonten vaskuliitit.

Temporal arteritis (giant cell arteritis), and Takayasu's arteritis are the two primary large-vessel vasculitides. Both are characterized by activation of the adaptive immune system in the vessel wall and activation of the innate immune system, manifesting as systemic inflammatory symptoms and an acute phase reaction. The clinical findings in temporal arteritis commonly include visual loss, headache, scalp tenderness, jaw claudication and polymyalgia rheumatica. Takayasu's arteritis begins with non-specific symptoms followed by decreased perfusion of the extremities, internal organs and brain as the disease progresses to vessel narrowing. Temporal artery biopsy is the gold standard for diagnosing temporal arteritis, whereas the diagnosis of Takayasu's arteritis relies on magnetic angiography or computed tomography angiography of the aorta and its branches. Glucocorticoids are the cornerstone of treatment of both diseases. In selected cases of Takayasu's arteritis methotrexate and tumour necrosis factor inhibitors have proved useful.

Low TNF-induced NF-kappaB and p38 phosphorylation levels in leucocytes in tumour necrosis factor receptor-associated periodic syndrome.

OBJECTIVE: TNF receptor-associated periodic syndrome (TRAPS) is a systemic autoinflammatory disorder caused by mutations in the type 1 TNF receptor (TNFRSF1A) gene. Because the pathomechanism of TRAPS may involve aberrant TNF-mediated intracellular signalling, we examined phosphorylation levels of nuclear factor kappaB (NF-kappaB) and p38 in response to TNF in 10 patients with three different TNFRSF1A mutations (C73R, C88Y and F112I). METHODS: Phosphorylation levels of NF-kappaB p65 and p38 were determined in fresh leucocytes stimulated with TNF (0-100 ng/ml) for 2.5-20 min and permeabilized for phospho-specific antibodies in a whole blood flow cytometry assay. As control agonists, we used bacterial lipopolysaccharide (LPS) and IFN-gamma, the latter mediating phosphorylation of the signal transducer and activator of transcription 1. Areas under curve values for dose-response and time course of NF-kappaB and p38 phosphorylation were calculated for the comparison of patients and reference subjects. RESULTS: NF-kappaB and p38 phosphorylation levels of monocytes, lymphocytes and neutrophils stimulated with TNF were significantly lower in TRAPS patients than in reference subjects. Phosphorylation levels induced by LPS, or by IFN-gamma, in patient and reference samples were comparable, indicating that the defect was confined to TNF-mediated signalling. CONCLUSIONS: In the three families studied, TRAPS was associated with low TNF-mediated signalling in leucocytes. This deficiency of the innate immune system may result in the activation of as yet unidentified compensatory regulatory mechanisms yielding the hyperinflammatory phenotype of TRAPS.

[Diagnosis and management of small vessel vasculitides]. / Pienten suonten vaskuliittien diagnostiikka ja hoito.

The spectrum of small vessel vasculitides includes Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome, Henoch-Schönlein purpura, cutaneous leukocytoclastic vasculitis and essential cryoglobulinemic vasculitis. The first three are characterized by the presence of circulating anti-neutrophil cytoplasmic antibodies (ANCA). The symptoms of vasculitis range from stable or slowly progressive to rapidly progressive glomerulonephritis or alveolar haemorrhage. The diagnosis of small vessel vasculitis should preferably rely on both clinical findings and histopathological examination of the organ involved. Cyclophosphamide combined with glucocorticoids is still standard therapy for remission induction in generalized ANCA-associated vasculitis. In severe cases the use of plasmapheresis treatment has been advocated. Medications suitable for remission maintenance include azathioprine, methotrexate, leflunomide and mycophenolate mofetil. Early experience with biologic drugs, particularly with rituximab, for refractory disease has been quite promising.

[Central nervous system vasculitis]. / Keskushermostovaskuliitit.

Central nervous system vasculitides are rare and life-threatening diseases with challenging diagnostics. Their neurological symptom spectrum is multifaceted: the patient may have intense headache, confusion, decreased cognitive function, changes in consciousness, epileptic attacks and symptoms resembling multiple sclerosis. Angiographic investigations, magnetic resonance imaging of the brain and examination of cerebrospinal fluid will clarify the diagnosis, but brain biopsy may be required to confirm the diagnosis. In differential diagnostics, special attention should be paid to cerebrovascular vasoconstriction syndromes. Standard therapy of cerebral vasculitis includes corticosteroids often combined with immunosuppressants.

Diagnostic performance and utility of very high-resolution ultrasonography in diagnosing giant cell arteritis of the temporal artery.

OBJECTIVE: Very-high resolution US (VHRU; 55 MHz) provides improved resolution and could provide non-invasive diagnostic information in GCA of the temporal artery. The objective of this study was to assess the diagnostic utility of VHRU-derived intima thickness (VHRU-IT) in comparison to high-resolution US halo-to-Doppler ratio (HRU-HDR) in patients referred for temporal artery biopsy. METHODS: VHRU and HRU of the temporal artery were performed before a biopsy procedure in 78 prospectively recruited consecutive patients who had received glucocorticoid treatment for a median of 8 days (interquartile range 0-13 days) before imaging. Based on the final diagnosis and biopsy findings, the study population was divided into the following four groups: non GCA (n = 40); clinical GCA with no inflammation on biopsy (n = 15); clinical GCA with inflammation limited to adventitia (n = 9); and clinical GCA with transmural inflammation (TMI; n = 11). RESULTS: Both VHRU and HRU were useful for identifying subjects with TMI, with VHRU outperforming HRU (area under curve: VHRU-IT 0.99, 95% CI 0.97, 1.00; HRU-HDR 0.74, 95% CI 0.52, 0.96; P=0.026). The diagnostic utility for diagnosing clinical GCA (negative biopsy) or inflammation limited to the adventitia was poor for both VHRU and HRU-HDR. From 5 days after initiation of glucocorticoid treatment, VHRU-IT was increased in eight of nine patients, whereas HRU-HDR was positive in three of seven patients. Both methods showed excellent inter-observer agreement (Cohen's κ: VHRU-IT 0.873; HRU-HDR 0.811). CONCLUSION: In suspected GCA, VHRU allows non-invasive real-time imaging of TMI manifestations of the temporal artery wall. VHRU-derived intimal thickness measurement seems to be more sensitive than the halo sign and HRU-HDR in detecting TMI in patients with prolonged glucocorticoid treatment.

Non-Invasive Vascular Very-High Resolution Ultrasound to Quantify Artery Intima Layer Thickness: Validation of the Four-Line Pattern.

Preliminary findings suggest that very-high resolution ultrasound (VHRU, 55 MHz) could differentiate arterial intima layer thickness (IT) non-invasively in vivo. We aimed to validate ultrasound-derived IT measurements and describe a four-line pattern consistent with intimal thickening. VHRU was applied to temporal arteries of 37 patients with suspected giant cell arteritis without inflammation on histology. Anatomically matched ultrasound-derived measurements of arterial layer thickness with the leading-edge method was compared to histology. Intimal thickening (IT >0.06 mm on histology) was identified as a four-line pattern in VHRU with a sensitivity of 96.3% and a specificity of 100%. Histologic and VHRU IT measurement agreement was excellent (mean difference 0.007 mm; 95% limits of agreement, -0.043 to 0.057) and intra-class coefficient (ICC) 0.923 (95% confidence interval [CI], 0.833-0.964). Intra- and inter-observer agreements for VHRU IT were high: ICC 0.946 (95% CI, 0.877-0.976) and 0.872 (95% CI, 0.773-0.943). VHRU utilizing the leading-to-leading edge method allows accurate and reliable measurements of arterial IT in patients with IT >0.06 mm. Measurements of IT will provide the opportunity to explore early subclinical structural intimal changes in the arterial wall increasing with age.

Transthyretin microheterogeneity and molecular interactions: implications for amyloid formation.

Aggregation of transthyretin (TTR), a plasma-binding protein for thyroxine and retinol-binding protein, is the cause of several amyloid diseases. Disease-associated mutations are well known, but wild-type TTR is, to a lesser extent, also amyloidogenic. Monomerization, not oligomer formation as in several other depository diseases, is the rate-limiting step in TTR aggregation, and stabilization of the natively tetrameric form can inhibit amyloid formation. Modifications on Cys10, as well as interactions with native ligands in plasma, were early found to influence the equilibrium between tetrameric and monomeric TTR by dissociating or stabilizing the tetramer. Following these discoveries, synthetic ligands for pharmacological prevention of TTR aggregation could be developed. In this article, we outline how the different types of TTR interactions and its microheterogeneity in plasma are related to its propensity to form amyloid fibrils. We conclude that plasma constituents and dietary components may act as natural TTR stabilizers whose mechanisms of action provide cues for the amelioration of TTR amyloid disease.

Setting up TRAPS.

Tumour necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS) is a dominantly inherited autoinflammatory disease caused by heterozygous mutations in the TNFRSF1A gene encoding for the TNF receptor 1 (TNFR1). TRAPS is a multi-faceted and heterogeneous disease which commonly manifests as recurrent episodes of high fever accompanied by abdominal pain, pleurisy, migratory rash, and myalgia. Disease attacks occur spontaneously or may be elicited by minor triggers. Because of a vigorous and sustained acute-phase response it may be complicated by systemic AA amyloidosis. Therapeutically interleukin-1 blockade seems even more promising than TNF blockade. Studies on the pathogenesis of TRAPS have shown TNFα-dependent cellular signalling to be defective, an enigmatic finding considering the hyperinflammatory phenotype of the disease. Several studies indicate that most mutated receptors never reach the cell surface but are misfolded and trapped in the endoplasmic reticulum, where they may elicit an intracellular inflammatory response, and thus lead to constitutional expression of proinflammatory cytokines. The aim of this review is to describe the current understanding of the pathogenesis of TRAPS by integrating recent clinical and laboratory data.

Beneficial effect of interleukin 1 inhibition with anakinra in adult-onset Still's disease. An open, randomized, multicenter study.

OBJECTIVE: To study the efficacy of anakinra versus disease-modifying antirheumatic drugs (DMARD) in refractory adult-onset Still's disease (AOSD). METHODS: In a 24-week study, 22 patients with AOSD taking prednisolone ≥ 10 mg/day received anakinra (n = 12) or DMARD (n = 10). The primary endpoint was achievement of remission. RESULTS: At 8 and 24 weeks, 7/12 and 6/12 receiving anakinra and 5/10 and 2/10 receiving DMARD achieved remission. Anakinra induced greater improvement in physical health measured by Medical Outcomes Study Short-Form 36 (SF-36; p < 0.011). During an open-label extension (OLE) of 28 weeks, 7/14 patients taking anakinra and 2/3 taking DMARD were in remission. CONCLUSION: Anakinra induced more beneficial responses than DMARD in patients with AOSD and was favored in the OLE phase. (ClinicalTrials.gov Protocol Registration NCT01033656).

Expression of APRIL in diffuse large B cell lymphomas from patients with systemic lupus erythematosus and rheumatoid arthritis.

OBJECTIVE: Patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) have an increased risk of diffuse large B cell lymphoma (DLBCL). The cytokine A PRoliferating-Inducing Ligand (APRIL) is strongly expressed in DLBCL in the general population and is detected in high concentrations in sera from subgroups of patients with RA and SLE. To investigate a possible association between APRIL and DLBCL in RA and SLE, we examined APRIL expression in lymphoma biopsies from patients with RA and SLE and from DLBCL patients without inflammatory disease. METHODS: Lymphoma tissue from 95 RA, 12 SLE, and 63 comparator DLBCL cases were stained with anti-APRIL antibodies (Aprily-2). The percentage of positively stained cells of the comparator cases were divided into quartiles (1-4, where 4 = most stained) and compared with the results for the RA and SLE lymphomas. APRIL expression was correlated to clinical variables. RESULTS: The odds ratio for high expression of APRIL (quartiles 3 and 4) was elevated in the SLE DLBCL (OR 23.6, 95% CI 2.4-231.2), but not in the RA DLBCL (OR 0.8, 95% CI 0.3-2.0). RA patients in quartile 4 had higher cumulated RA disease activity than those in quartile 1 (p = 0.013). Epstein-Barr virus in the lymphoma tissue was associated with high APRIL expression (p = 0.009). CONCLUSION: The high expression of APRIL in DLBCL in SLE and in an RA subset might indicate an association between APRIL and lymphoma in these subsets of rheumatic diseases, but could also reflect a dysregulation of APRIL per se in these patient groups.

A marked decline in the incidence of renal replacement therapy for amyloidosis associated with inflammatory rheumatic diseases - data from nationwide registries in Finland.

Risk for amyloidosis in rheumatic diseases is associated with a long-lasting inflammation. To assess possible changes in the incidence of terminal uraemia due to amyloidosis associated with rheumatic diseases on a nationwide basis, we scrutinised the files of the Finnish Registry for Kidney Diseases for patients suffering from amyloidosis associated with rheumatoid arthritis (RA), ankylosing spondylitis (AS) or juvenile idiopathic arthritis (JIA) over the period 1995-2008. The registry has an estimated 97-99% coverage of all patients accepted for renal replacement therapy (RRT) in the country. Data on the consumption of antirheumatic drugs were collected from two sources: the Social Insurance Institution's Drug Reimbursement Register, and the Sales Register of the National Agency for Medicines from the above period. Altogether 264 cases were identified. Two hundred twenty-nine of them had RA, 15 AS and 20 JIA. When the total annual number of new admissions to RRT varied between 20 and 37 at the end of 1990s, it was under half of that from 2002 onwards. Over this period, the number of users of low-dose methotrexate (MTX) has increased 3.6-fold, the drug being the most frequently used disease modifying anti-rheumatic drug in Finland. The present nationwide series is the first to show that the incidence of end-stage renal disease due to amyloidosis associated with rheumatic diseases is decreasing. An obvious reason for this is intensive anti-rheumatic drug therapy.

Amyloidosis-recent developments.

OBJECTIVES: To describe the clinical presentation, diagnosis, classification, grading, evaluation of prognosis, and treatment of amyloidosis against the background of its pathomechanisms. METHODS: PubMed and MEDLINE databases (1990 to October 2007) and internet were searched for the key word amyloidosis and evaluated on the basis of the authors' own clinical experience and work on the topic. RESULTS: A clinical suspicion of amyloidosis arises when a patient with a chronic inflammatory disease, plasma cell dyscrasia, or a family history of hereditary amyloidosis develops "an amyloid syndrome" or more rare but specific signs. Microscopy of Congo red stained tissue specimens under polarized light shows birefringent amyloid, which is typed by identification of the amyloid precursor by immunohistochemistry, amino acid sequencing, or proteomics. The diagnosis can be supported by genetic tests. Amyloidosis now covers biochemically and clinically 27 distinct types in man and 9 in animals. Grading to mild, moderate, and severe disease based on laboratory tests and radiology is introduced. Prognosis is affected by the rate of synthesis and the concentration of the circulating precursor. Accurate diagnosis of the underlying disease is mandatory as the treatment is based on disease control and inhibition of amyloid precursor production. Organ-specific treatment, such as transplantation, hemodialysis, treatment of heart failure, pacemakers, and substitution to prevent nutritional deficiencies, is often needed. CONCLUSIONS: As our knowledge of the pathogenesis of amyloidosis and the structure-function relationship of amyloid proteins increases, new therapies will be developed to prevent protein misfolding and aggregation, inhibit fibrillogenesis, and enhance clearance of amyloid.