A common pathway in periodic fever syndromes

The Influence of Coexisting Familial Mediterranean Fever on Crohn's Disease: Data From an FMF Endemic Area

GOAL

The goal of this study was to evaluate the impact of coexisting familial Mediterranean fever (FMF) on Crohn's disease (CD) patients' phenotype and disease course in an endemic region for FMF.

BACKGROUND

CD and FMF are inflammatory diseases characterized by recurrent abdominal pain and fever attacks. The impact of coexisting FMF on CD patients' phenotype and disease course is currently unknown.

MATERIALS AND METHODS

We reviewed the medical records of 210 adult CD patients who were regularly followed up at a tertiary gastroenterology clinic between November 2006 and April 2018. The patients were divided into FMF positive (CD-FMF) and FMF negative (CD-control) groups. The severity of CD was assessed by the rate of hospitalization because of CD, the need for biological therapy, and whether surgery was performed for CD.

RESULTS

Eight (3.8%) of 210 CD patients have concomitant FMF, which is 35 to 40 times higher than expected in an endemic region for FMF. Baseline demographic parameters, location/behavior of the CD, and initial therapeutic regimens were similar between the 2 groups. The prevalence of peripheral arthritis was significantly higher in CD-FMF group (37.5% vs. 10.4%, respectively, P =0.04). A significantly greater proportion of the CD-FMF patients had received biological therapy (50% vs. 11.9%; P =0.012). Steroid dependence and CD-related hospitalization rates in the CD-FMF group were relatively higher but were not statistically significant (37.5% vs. 15.3 and 62.5% vs. 41.1%).

CONCLUSIONS

Our findings indicate that the disease course of CD tends to be more severe in patients with coexisting FMF.

Detection of a rare variant in PSTPIP1 through three generations in a family with an initial diagnosis of FMF/MKD-overlapping phenotype

OBJECTIVE

The presence of FMF cases without MEFV (MEFV innate immunity regulator, pyrin) pathogenic variants led us to search for other genes' involvement in the disease development. Here, we describe the presence of genetic heterogeneity in a three-generation family with an FMF/mevalonate kinase deficiency (MKD)-overlapping phenotype without MEFV/MVK (mevalonate kinase) pathogenic variants.

METHOD

Targeted sequencing revealed a rare, fully penetrant variant in PSTPIP1 (p.Arg228Cys, rs781341816). Computational stability analyses of PSTPIP1 protein were performed. PSTPIP1-pyrin protein interaction was examined by immunoprecipitation and immunoblotting in peripheral blood mononuclear cells (PBMCs) of patients and healthy controls. PBMCs were cultured, and inflammation was induced by LPS+ATP treatment, followed by protein level measurements of caspase-1, IL1ß, pyrin and PSTPIP1 in cell lysates and mature caspase-1 and mature IL1ß in supernatants.

RESULTS

The conserved, rare (GnomAD, 0.000028) PSTPIP1 p.Arg228Cys variant, previously reported in ClinVar as a variant with uncertain significance, showed complete penetrance in the family presenting an autosomal dominant pattern. Computational analyses showed a potentially destabilizing effect of the variant on PSTPIP1 protein. Accordingly, PSTPIP1-pyrin interaction was increased in patients harboring the variant, which resulted in elevated levels of mature caspase-1 and IL1ß in the inflammation-induced patient samples.

CONCLUSIONS

Unlike previously described cases with pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA)-associated PSTPIP1 variants, our patients with the p.Arg228Cys variant presented with an FMF/MKD-overlapping phenotype. As additional data on the genetic heterogeneity in the variable clinical spectrum of autoinflammatory syndromes, we suggest that the p.Arg228Cys variant in PSTPIP1 is related to inflammation responses through strong PSTPIP1-pyrin interaction and pyrin inflammasome activation.

Comparison of the histopathological characteristics of diffuse sclerosing osteomyelitis of the mandible, chronic suppurative osteomyelitis, and craniofacial fibrous dysplasia

BACKGROUND

There are relatively few reports on the histopathological characteristics of diffuse sclerosing osteomyelitis of the mandible (DSOM), which is difficult to distinguish from chronic suppurative osteomyelitis (CSO) and craniofacial fibrous dysplasia (CFD). This study aimed to summarize and compare the histopathological characteristics of DSOM, CFD, and CSO.

MATERIALS AND METHODS

In this study, hematoxylin and eosin-stained sections of patients with DSOM, CSO, and CFD at the Peking University Hospital of Stomatology from 2015 to 2020 were retrieved. The histopathological characteristics were summarized, including new bone formation, inflammatory cell infiltration, bone trabecular morphology, osteoclasts, sequestrum, bacterial mass, and calcified spherules, similar to cementicles. The histopathological characteristics of DSOM, CSO, and CFD were compared, and the results were statistically analyzed.

RESULTS

In total, 50, 13, and 10 patients with DSOM, CSO, and CFD were included in this study, respectively. In terms of new bone formation, both DSOM and CSO showed reactive bone formation (p = 1), whereas CFD mainly showed fiber osteogenesis (p < 0.001). The inflammatory cells of DSOM were mainly lymphocytes and plasma cells, whereas those of CSO were mainly lymphocytes and neutrophils (p < 0.001), and there was usually no inflammatory cell infiltration in the CFD specimens (p < 0.001). DSOM, CSO, and CFD showed irregular bone trabeculae (p = 0.045, p = 0.703) and active osteoclasts (p1 = 0.189, p2 = 0.256). DSOM showed a small amount of bacterial mass but no sequestrum; neither of which was found in CFD (p = 1, p = 1), but it was common in CSO (p = 0.011 and p = 0.025). DSOM and CSO showed smooth and regular basophilic lines (p = 0.308), whereas CFD showed a rough and irregular basophilic line (p < 0.001).

CONCLUSIONS

The histopathological characteristics of the three diseases were partly similar, but there were evident differences. The main differences are the type of new bone formation, types and distribution of inflammatory cells, and presence of sequestrum and bacterial masses. These differences will help clinicians diagnose DSOM.

Imaging findings of sterile pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome: differential diagnosis and review of the literature

Pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome is a rare autosomal-dominant autoinflammatory disease of incomplete penetrance and variable expression. PAPA syndrome is the result of a mutation in the proline serine threonine phosphatase-interacting protein 1 (PSTPIP1/CD2BP1) gene located on chromosome 15, which results in an abnormal overproduction of the pro-inflammatory cytokine interleukin-1β (IL-1). This syndrome clinically manifests as early onset of recurrent episodes of acute aseptic inflammation of the joints, generally occurring in the first two decades of life, followed by manifestation of characteristic skin lesions in the third decade, after an obvious decline in the joint symptoms. Although uncommon, the potential clinical implications of PAPA syndrome warrant an appropriate diagnosis in a timely fashion.

Hof1 and Chs4 Interact via F-BAR Domain and Sel1-like Repeats to Control Extracellular Matrix Deposition during Cytokinesis

Localized extracellular matrix (ECM) remodeling is thought to stabilize the cleavage furrow and maintain cell shape during cytokinesis [1-14]. This remodeling is spatiotemporally coordinated with a cytoskeletal structure pertaining to a kingdom of life, for example the FtsZ ring in bacteria [15], the phragmoplast in plants [16], and the actomyosin ring in fungi and animals [17, 18]. Although the cytoskeletal structures have been analyzed extensively, the mechanisms of ECM remodeling remain poorly understood. In the budding yeast Saccharomyces cerevisiae, ECM remodeling refers to sequential formations of the primary and secondary septa that are catalyzed by chitin synthase-II (Chs2) and chitin synthase-III (the catalytic subunit Chs3 and its activator Chs4), respectively [18, 19]. Surprisingly, both Chs2 and Chs3 are delivered to the division site at the onset of cytokinesis [6, 20]. What keeps Chs3 inactive until secondary septum formation remains unknown. Here, we show that Hof1 binds to the Sel1-like repeats (SLRs) of Chs4 via its F-BAR domain and inhibits Chs3-mediated chitin synthesis during cytokinesis. In addition, Hof1 is required for rapid accumulation as well as efficient removal of Chs4 at the division site. This study uncovers a mechanism by which Hof1 controls timely activation of Chs3 during cytokinesis and defines a novel interaction and function for the conserved F-BAR domain and SLR that are otherwise known for their abilities to bind membrane lipids [21, 22] and scaffold protein complex formation [23].

Current knowledge on procaspase-1 variants with reduced or abrogated enzymatic activity in autoinflammatory disease

Caspase-1 is a proinflammatory enzyme that is essential in many inflammatory conditions including infectious, autoimmune, and autoinflammatory disorders. The inflammation is mainly mediated by the generation of inflammasomes that activate caspase-1 and subsequently interleukin (IL)-1β and IL-18. In addition, homotypic CARD/CARD interaction of procaspase-1 with RIP2 and thereby activation of the NF-κB pathways may play some role in the inflammation. However, normally, this pathway seems to become downregulated rapidly by the cleavage and excretion of RIP2 by active (pro-)caspase-1. In patients with unexplained recurrent systemic inflammation, CASP1 variants were detected, which often destabilized the caspase-1 dimer interface. Obviously, the resulting decreased or abrogated enzymatic activity and IL-1β production did not prevent the febrile episodes. As an unexpected finding, the inactive procaspase-1 variants significantly enhanced proinflammatory signaling by increasing RIP2 mediated NF-κB activation in an in vitro cell transfection model. A likely reason is the failure of inactive procaspase-1 to cleave bound RIP2 and also to mediate its excretion out of the intracelluar space thereby keeping the RIP2-NF-κB pathway upregulated. Hence, proinflammatory effects of enzymatically inactive procaspase-1 variants may partially explain the inflammatory episodes of the patients.

Detection of Mediterranean fever gene mutations in Egyptian children with inflammatory bowel disease

AIM

The aim of the current study is to investigate the prevalence of familial Mediterranean fever gene (MEFV) mutations in a cohort of Egyptian children with inflammatory bowel disease (IBD), and to characterize familial Mediterranean fever (FMF)-IBD patients, helping better understanding of IBD pathogenesis.

METHODS

The study enrolled 17 patients with ulcerative colitis (UC), 15 with Crohn's disease(CD), 10 with indeterminate colitis (IC) and 33 healthy children as controls. All cases and controls were tested for 12 FMF gene mutations by reverse hybridization after multiplex polymerase chain reaction amplification and DNA sampling.

RESULTS

Eighty-eight percent of the IBD patients carried the mutations, with Sequence variant V627A being the commonest versus 42.4% of controls. No associations were found between MEFV gene mutations, and phenotypic characteristics of IBD patients.

CONCLUSION

IBD patients, in populations with a high background carrier rate of MEFV variants, should be screened for MEFV gene mutations, especially those diagnosed as indeterminate colitis. Testing larger numbers of healthy Egyptian children for MEFV gene mutation is important to further determine the allele frequency in Egypt.

Association of familial Mediterranean fever in Turkish children with inflammatory bowel disease

AIM

Familial Mediterranean fever (FMF) and inflammatory bowel disease (IBD) carry similar clinical and biological properties. Both are characterized with chronic inflammation attacks and neutrophil migration and impaired apoptosis mechanism are present in the areas of damage in both conditions. In our study, we aimed to determine the frequency of association of FMF in patients with IBD, to compare the demographic, clinical, laboratory and treatment response properties in these patients with the ones in other IBD patients and to determine association of FMF especially in treatment-resistant patients.

MATERIAL AND METHODS

Fifty-three patients who were being followed up with a diagnosis of IBD aged between 0 and 18 years were included in the study. The patient group included the patients who were diagnosed with IBD according to clinical, serological, endoscopic and histopathological criteria, who were being followed up and whose therapies were continuing. Genetic analysis in terms of MEFV gene mutations was performed in all patients with a diagnosis of IBD. Acute phase reactants, complete blood count, immunoglobulin levels, stool analysis, "perinuclear anti-neutrophil cytoplasmic antibodies" (pANCA) and "anti-Saccharomyces cerevisiae antibodies" (ASCA) were studied at the time of diagnosis. The diagnosis of FMF was made according to detailed history, physical examination findings, laboratory tests and the results of genetic analyses in terms of MEFV gene mutations in accordance with the criteria defined in 2009.

RESULTS

We found that FMF accompanied in 14 (26.4%) of the patients who had a diagnosis of IBD. 3 of these 14 patients in whom FMF accompanied were being followed up with a diagnosis of Crohn disease and 11 were being followed up with a diagnosis of ulcerative colitis. All of these patients had MEFV gene mutation. These mutations included M694V (50%), K695R (21.4%), M680I (14.3%) and R202Q (14.3%) in order of frequency. When the laboratory data were compared between the patients who had a diagnosis of IBD alone and who had a diagnosis of IBD plus FMF, it was observed that the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values were statistically significantly higher in the IBD+FMF group.

CONCLUSIONS

FMF is a common condition in the Turkish population and M694V mutation is found most commonly. In our study, this status did not change in cases where FMF accompanied IBD, but K695R mutation was found more frequently compared to FMF alone. We think that it should be kept in mind that other inflammatory conditions including mainly FMF may accompany IBD, if a case of IBD does not have an expected course or is resistant to treatment.

Update on research and clinical translation on specific clinical areas: From bench to bedside: How insight in immune pathogenesis can lead to precision medicine of severe juvenile idiopathic arthritis

Despite the enormous progress in the treatment of juvenile idiopathic arthritis (JIA), innovations based on true bench-to-bedside research, performed in JIA patients, are still scarce. This chapter describes novel developments in which clinical innovations go hand in hand with basic discoveries. For the purpose of this review, we will mainly focus on developments in severe forms of JIA, most notably systemic JIA and polyarticular JIA. However, also in less severe forms of JIA, such as oligoarticular JIA, better insight will help to improve diagnosis and treatment. Facilitating the transition from bench to bedside will prove crucial for addressing the major challenges in JIA management. If successful, it will set new standards for a safe, targeted and personalized therapeutic approach for children with JIA.

Alarmins, inflammasomes and immunity

The elaboration of an effective immune response against pathogenic microbes such as viruses, intracellular bacteria or protozoan parasites relies on the recognition of microbial products called pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs) such as Toll-like receptors (TLRs). Ligation of the PRRs leads to synthesis and secretion of pro-inflammatory cytokines and chemokines. Infected cells and other stressed cells also release host-cell derived molecules, called damage-associated molecular patterns (DAMPs, danger signals, or alarmins), which are generic markers for damage. DAMPs are recognized by specific receptors on both immune and nonimmune cells, which, depending on the target cell and the cellular context, can lead to cell differentiation or cell death, and either inflammation or inhibition of inflammation. Recent research has revealed that DAMPs and PAMPs synergize to permit secretion of pro-inflammatory cytokines such as interleukin-1β (IL-1β): PAMPs stimulate synthesis of pro-IL-1β, but not its secretion; while DAMPs can stimulate assembly of an inflammasome containing, usually, a Nod-like receptor (NLR) member, and activation of the protease caspase-1, which cleaves pro-IL-1β into IL-1β, allowing its secretion. Other NLR members do not participate in formation of inflammasomes but play other essential roles in regulation of the innate immune response.

Association of inflammatory bowel disease with familial Mediterranean fever in Turkish children

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) and familial Mediterranean fever (FMF) share common clinical and biological features. The prevalence of other inflammatory diseases, including IBD, is increased in FMF. We investigated the presence of IBD accompanying FMF in patients who were being followed up with a diagnosis of FMF and the relation of IBD with the MEFV gene mutation.

METHODS

A total of 78 children with FMF were enrolled in the study. The patients were included in the study independent of the presence of complaints. Colonoscopy for IBD was performed if any of the following was present: blood mixed with mucus in the stool; chronic diarrhea (loose and frequent stools lasting >4 weeks); abdominal pain incompatible with FMF (localized in a certain part of the abdomen, not occurring during attacks, >3 days); and positive IgA and IgG anti-Saccharomyces cerevisiae antibodies and perinuclear antineutrophil cytoplasmic antibodies. MEFV gene mutations were analyzed in patients diagnosed as having IBD and FMF.

RESULTS

Of the 78 patients with a diagnosis of FMF, colonoscopy was performed and biopsy samples were taken in 20 patients (25.6%) who had abdominal pain incompatible with FMF, chronic diarrhea, bloody stools, and/or positive perinuclear anti-neutrophil cytoplasmic antibody or anti-Saccharomyces cerevisiae antibody. Histopathological examination resulted in a diagnosis of IBD in 12 of the 78 patients (15.4%). MEFV gene mutations were present in all 12 patients diagnosed as having IBD. We observed M694 V mutations in 5 of 12 patients (41.7%), M680I mutations in 3 (25%), K695R mutations in 3 (25%), and E148Q mutations in 1 (8.3%).

CONCLUSIONS

We found that the number of patients with FMF was higher than the number with IBD in the general population. When IBD accompanied FMF, the most common mutation was M694 V; however, the high rate (25%) of K695R mutation in our patients with FMF and IBD was not observed in previous studies.

Association of the MEFV gene variations with inflammatory bowel disease in Turkey

BACKGROUND

Association of NOD2 (CARD15) gene mutations with inflammatory bowel diseases (IBD) is well known. We herein aimed to investigate the role of familial Mediterranean fever-associated MEFV variations in IBD patients as additional regional-specific risk factor.

STUDY

One hundred thirty-seven (78 female, 56.9%) IBD patients [62 Crohn's disease (CD), 75 ulcerative colitis (UC)] were enrolled into the study. The diagnosis of all patients was confirmed by colonoscopy, histopathology, and the clinical findings. One hundred one healthy donors' samples were used as healthy controls. All patients were genotyped for the most common E148Q, M608I, M694V, and V726A variations of the MEFV and R702W, G908R, and 1007fs of the NOD2.

RESULTS

The overall MEFV variation frequency was found to be higher in the IBD (25.5%) patients (28% in UC, 22.6% in CD) compared with controls (9.9%, P=0.006). This association was stronger with the penetrant exon 10 variations (M694V, M680I, V726A; odds ratio =4.5, P=0.001). Contribution of M694V was higher compared with the other variations (14.5% in CD, 17.3% in UC and 3% in controls, odds ratio =6.039, 95% confidence intervals, 1.7-20.7, P=0.002). The overall frequency of 3 NOD2 variants in the IBD group was not different from that of controls.

CONCLUSIONS

The results of this study suggest that the MEFV variations may be an additional susceptibility factor for IBD in certain parts of the world where the carrier rate is high, and the genetic background of the IBD patients may show regional changes.

Autoinflammatory bone disorders

Autoinflammatory bone disorders are characterized by chronic non-infectious osteomyelitis and inflammation-induced bone resorption and result from aberrant activation of the innate immune system. Sporadic chronic non-bacterial osteomyelitis (CNO) is the most common disease subtype. The clinical picture is highly variable and the exact underlying pathophysiology remains to be determined. Recently, novel insights in the pathophysiology of sterile bone inflammation have been gathered by analyzing patients with rare, monogenic inflammatory diseases. In this overview CNO and Majeed syndrome, cherubism, hypophosphatasia and primary hypertrophic osteoarthropathy will be discussed. For the latter four disorders, a genetic cause affecting bone metabolism and leading to chronic bone inflammation has been described. The exact pathophysiology of CNO remains to be determined. Insights from monogenic autoinflammatory bone diseases and the identification of distinct inflammatory pathways may help to understand the pathogenesis of bone inflammation and inflammation-induced bone resorption in more common diseases.

Spontaneous inflammatory pain model from a mouse line with N-ethyl-N-nitrosourea mutagenesis

BACKGROUND

N-ethyl-N-nitrosourea mutagenesis was used to induce a point mutation in C57BL/6 J mice. Pain-related phenotype screening was performed in 915 G3 mice. We report the detection of a heritable recessive mutant in meiotic recombinant N1F1 mice that caused an abnormal pain sensitivity phenotype with spontaneous skin inflammation in the paws and ears.

METHODS

We investigated abnormal sensory processing, neuronal peptides, and behavioral responses after the induction of autoinflammatory disease. Single-nucleotide polymorphism (SNP) markers and polymerase chain reaction product sequencing were used to identify the mutation site.

RESULTS

All affected mice developed paw inflammation at 4-8 weeks. Histological examinations revealed hyperplasia of the epidermis in the inflamed paws and increased macrophage expression in the spleen and paw tissues. Mechanical and thermal nociceptive response thresholds were reduced in the affected mice. Locomotor activity was decreased in affected mice with inflamed hindpaws, and this reduction was attributable to the avoidance of contact of the affected paw with the floor. Motor strength and daily activity in the home cage in the affected mice did not show any significant changes. Although Fos immunoreactivity was normal in the dorsal horn of affected mice, calcitonin gene-related peptide immunoreactivity significantly increased in the deep layer of the dorsal horn. The number of microglia increased in the spinal cord, hippocampus, and cerebral cortex in affected mice, and the proliferation of microglia was maintained for a couple of months. Two hundred eighty-five SNP markers were used to reveal the affected gene locus, which was found on the distal part of chromosome 18. A point mutation was detected at A to G in exon 8 of the pstpip2 gene, resulting in a conserved tyrosine residue at amino acid 180 replaced by cysteine (Y180 C).

CONCLUSIONS

The data provide definitive evidence that a mutation in pstpip2 causes autoinflammatory disease in an N-ethyl-N-nitrosourea mutagenesis mouse model. Thus, our pstpip2 mutant mice provide a new model for investigating the potential mechanisms of inflammatory pain.

Autoinflammatory syndromes: diagnosis and management

During the last decades the description of autoinflammatory syndromes induced great interest among the scientific community. Mainly rheumatologists, immunologists and pediatricians are involved in the discovery of etiopathogenesis of these syndromes and in the recognition of affected patients. In this paper we will discuss the most important clues of monogenic and non-genetic inflammatory syndromes to help pediatricians in the diagnosis and treatment of these diseases.

Familial mediterranean Fever: a retrospective clinical and molecular study in the East of anatolia region of Turkey

Familial Mediterranean Fever (FMF) is an autoinflammatory periodic disorder. We aim to identify the distribution and the frequency of the Mediterranean Fever (MEFV) gene mutations in the east of Anatolia in Turkey and perform a genotype/phenotype correlation in the patients’ cohort. The study was carried out on 415 clinically diagnosed Turkish FMF patients and 103 healthy controls. The tested individuals were screened for the most common twelve MEFV mutations. The most important features were the predominance of the M694V and E148Q mutations in patient group and the earlier of onset of the disease in M694V mutation carriers compared with the carriers of other mutations (P=0.00). We discuss the high frequency of E148Q mutations in patient group compared with controls, genetic counseling in intermarriage families and the variations in mutation frequency according to regions of Turkey.

An infant with severe refractory Crohn's disease and homozygous MEFV mutation who dramatically responded to colchicine

Previous studies have suggested that inflammatory bowel disease is particulary frequent and severe in familial Mediterranean fever (FMF) families. An 8-month-old boy was admitted to our hospital with chronic bloody diarrhea, failure to thrive and high-grade fever. He was diagnosed as Crohn's disease (CD) based on clinical, laboratory and histological findings and, corticosteroid therapy was started. The patient did not respond to intensive medical therapy including intravenous corticosteroid, mesalazine, azathioprine, intravenous cyclosporine and enteral feeding. MEFV gene mutation analysis revealed homozygous M694V mutation. In addition to azathioprine and cyclosporine therapy, with the diagnosis of FMF, colchicine therapy was started and partial remission was observed within 2 weeks. To the best of our knowledge, this is the first report of association of CD and FMF in an infant. In cases of CD resistant to medical therapy, possibility of underlying FMF should be considered, especially in countries where FMF is prevalent.

Genetic variation in the familial Mediterranean fever gene (MEFV) and risk for Crohn's disease and ulcerative colitis

BACKGROUND AND AIMS

The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1beta processing. Pyrin has been shown to interact with the gene product of NLRP3, NALP3/cryopyrin, also an important active member of the inflammasome. The NLRP3 region was recently reported to be associated with Crohn's disease (CD) susceptibility. We therefore sought to evaluate MEFV as an inflammatory bowel disease (IBD) susceptibility gene.

METHODOLOGY AND RESULTS

MEFV colonic mucosal gene expression was significantly increased in experimental colitis mice models (TNBS p<0.0003; DSS p<0.006), in biopsies from CD (p<0.02) and severe ulcerative colitis (UC) patients (p<0.008). Comprehensive genetic screening of the MEFV region in the Belgian exploratory sample set (440 CD trios, 137 UC trios, 239 CD cases, 96 UC cases, and 107 healthy controls) identified SNPs located in the MEFV 5' haplotype block that were significantly associated with UC (rs224217; p = 0.003; A allele frequency: 56% cases, 45% controls), while no CD associations were observed. Sequencing and subsequent genotyping of variants located in this associated haplotype block identified three synonymous variants (D102D/rs224225, G138G/rs224224, A165A/rs224223) and one non-synonymous variant (R202Q/rs224222) located in MEFV exon 2 that were significantly associated with UC (rs224222: p = 0.0005; A allele frequency: 32% in cases, 23% in controls). No consistent associations were observed in additional Canadian (256 CD trios, 91 UC trios) and Scottish (495 UC, 370 controls) sample sets. We note that rs224222 showed marginal association (p = 0.012; G allele frequency: 82% in cases, 70% in controls) in the Canadian sample, but with a different risk allele. None of the NLRP3 common variants were associated with UC in the Belgian-Canadian UC samples and no significant interactions were observed between NLRP3 and MEFV that could explain the observed flip-flop of the rs224222 risk allele.

CONCLUSION

The differences in association levels observed between the sample sets may be a consequence of distinct founder effects or of the relative small sample size of the cohorts evaluated in this study. However, the results suggest that common variants in the MEFV region do not contribute to CD and UC susceptibility.

Targeted treatment of pyoderma gangrenosum in PAPA (pyogenic arthritis, pyoderma gangrenosum and acne) syndrome with the recombinant human interleukin-1 receptor antagonist anakinra

The triad of sterile pyogenic arthritis, pyoderma gangrenosum and acne is known by the acronym of PAPA syndrome. It is a rare autosomal dominant disease of early onset. The treatment of pyoderma gangrenosum is challenging as there is often only partial response to systemic glucocorticosteroids and immunosuppressive therapies. We report the rapid and lasting response of pyoderma gangrenosum to the targeted treatment with the recombinant human interleukin-1 receptor antagonist (rHuIL-1Ra) anakinra in a patient with PAPA syndrome.

The inflammasomes: guardians of the body

The innate immune system relies on its capacity to rapidly detect invading pathogenic microbes as foreign and to eliminate them. The discovery of Toll-like receptors (TLRs) provided a class of membrane receptors that sense extracellular microbes and trigger antipathogen signaling cascades. More recently, intracellular microbial sensors have been identified, including NOD-like receptors (NLRs). Some of the NLRs also sense nonmicrobial danger signals and form large cytoplasmic complexes called inflammasomes that link the sensing of microbial products and metabolic stress to the proteolytic activation of the proinflammatory cytokines IL-1beta and IL-18. The NALP3 inflammasome has been associated with several autoinflammatory conditions including gout. Likewise, the NALP3 inflammasome is a crucial element in the adjuvant effect of aluminum and can direct a humoral adaptive immune response. In this review, we discuss the role of NLRs, and in particular the inflammasomes, in the recognition of microbial and danger components and the role they play in health and disease.

An integrated classification of pediatric inflammatory diseases, based on the concepts of autoinflammation and the immunological disease continuum

Historically, pediatric inflammatory diseases were viewed as autoimmune but developments in genetics of monogenic disease have supported our proposal that "inflammation against self" be viewed as an immunologic disease continuum (IDC), with genetic disorders of adaptive and innate immunity at either end. Innate immune-mediated diseases may be associated with significant tissue destruction without evident adaptive immune responses and are designated as autoinflammatory due to distinct immunopathologic features. However, the majority of pediatric inflammatory disorders are situated along this IDC. Innate immunity has been demonstrated in polygenic disorders, particularly Crohn's disease (CD). A genetic overlap exists between CD and some major histocompatibility complex (MHC) class I-associated diseases, including psoriasis; these diseases seem to represent a true intermediate between autoinflammation and autoimmunity. Conversely, classical autoimmune diseases, with autoantibody and MHC class II associations, including celiac disease and rheumatoid arthritis (RA), have adaptive immune genetic associations, including Cytotoxic T-Lymphocyte Antigen-4 (CTLA4) and PTPN22. This proposed classification is clinically relevant, because innate immune-mediated disorders may respond to cytokine antagonism whereas autoimmune-mediated diseases respond better to anti-T and B cell therapies. Furthermore, the etiopathogenesis of poorly defined "autoimmune" diseases, such as juvenile idiopathic arthritis, may be inferred to have substantial innate immune involvement, based on response to IL-1 antagonism.

The Inflammasomes: Guardians of the Body

The innate immune system relies on its capacity to rapidly detect invading pathogenic microbes as foreign and to eliminate them. The discovery of Toll-like receptors (TLRs) provided a class of membrane receptors that sense extracellular microbes and trigger antipathogen signaling cascades. More recently, intracellular microbial sensors have been identified, including NOD-like receptors (NLRs). Some of the NLRs also sense nonmicrobial danger signals and form large cytoplasmic complexes called inflammasomes that link the sensing of microbial products and metabolic stress to the proteolytic activation of the proinflammatory cytokines IL-1β and IL-18. The NALP3 inflammasome has been associated with several autoinflammatory conditions including gout. Likewise, the NALP3 inflammasome is a crucial element in the adjuvant effect of aluminum and can direct a humoral adaptive immune response. In this review, we discuss the role of NLRs, and in particular the inflammasomes, in the recognition of microbial and danger components and the role they play in health and disease.

Auto-inflammatory syndromes and oral health

Auto-inflammatory diseases (periodic syndromes) are rare childhood-onset disorders which are characterized by fluctuating or recurrent episodes of fever and inflammation affecting serosal surfaces, joints, eyes and/or skin without significant autoantibody production or an identifiable underlying infection. They are disorders of innate immunity and the underlying genetic defect has been identified in most of the syndromes. Diagnosis relies on clinical symptoms and evidence of an elevated acute phase response during attacks, supported by finding mutations in the relevant genes. Several syndromes can lead to systemic AA amyloidosis. Aphthous-like oral ulceration has been reported as one manifestation in several of the syndromes, including periodic fever, aphthous-stomatitis, pharyngitis, adenitis (PFAPA) familial Mediterranean fever (FMF), hyperimmunoglobulinaemia D and periodic fever syndrome, tumour necrosis factor receptor associated periodic syndrome and pyogenic sterile arthritis, pyoderma gangrenosum, acne (PAPA). Chronic jaw recurrent osteomyelitis has been recorded in chronic recurrent multifocal osteomyelitis. Advances in the molecular pathogenesis of these syndromes and the regulation of innate immunity have enhanced diagnosis, and rationalized therapies. This article reviews the periodic fever syndromes relevant to oral health and the suggested association of FMF with Behçet's disease.

The Inflammasomes: Guardians of the Body

The innate immune system relies on its capacity to rapidly detect invading pathogenic microbes as foreign and to eliminate them. The discovery of Toll-like receptors (TLRs) provided a class of membrane receptors that sense extracellular microbes and trigger antipathogen signaling cascades. More recently, intracellular microbial sensors have been identified, including NOD-like receptors (NLRs). Some of the NLRs also sense nonmicrobial danger signals and form large cytoplasmic complexes called inflammasomes that link the sensing of microbial products and metabolic stress to the proteolytic activation of the proinflammatory cytokines IL-1β and IL-18. The NALP3 inflammasome has been associated with several autoinflammatory conditions including gout. Likewise, the NALP3 inflammasome is a crucial element in the adjuvant effect of aluminum and can direct a humoral adaptive immune response. In this review, we discuss the role of NLRs, and in particular the inflammasomes, in the recognition of microbial and danger components and the role they play in health and disease.

The Inflammasomes: Guardians of the Body

The innate immune system relies on its capacity to rapidly detect invading pathogenic microbes as foreign and to eliminate them. The discovery of Toll-like receptors (TLRs) provided a class of membrane receptors that sense extracellular microbes and trigger antipathogen signaling cascades. More recently, intracellular microbial sensors have been identified, including NOD-like receptors (NLRs). Some of the NLRs also sense nonmicrobial danger signals and form large cytoplasmic complexes called inflammasomes that link the sensing of microbial products and metabolic stress to the proteolytic activation of the proinflammatory cytokines IL-1β and IL-18. The NALP3 inflammasome has been associated with several autoinflammatory conditions including gout. Likewise, the NALP3 inflammasome is a crucial element in the adjuvant effect of aluminum and can direct a humoral adaptive immune response. In this review, we discuss the role of NLRs, and in particular the inflammasomes, in the recognition of microbial and danger components and the role they play in health and disease.

The Inflammasomes: Guardians of the Body

The innate immune system relies on its capacity to rapidly detect invading pathogenic microbes as foreign and to eliminate them. The discovery of Toll-like receptors (TLRs) provided a class of membrane receptors that sense extracellular microbes and trigger antipathogen signaling cascades. More recently, intracellular microbial sensors have been identified, including NOD-like receptors (NLRs). Some of the NLRs also sense nonmicrobial danger signals and form large cytoplasmic complexes called inflammasomes that link the sensing of microbial products and metabolic stress to the proteolytic activation of the proinflammatory cytokines IL-1β and IL-18. The NALP3 inflammasome has been associated with several autoinflammatory conditions including gout. Likewise, the NALP3 inflammasome is a crucial element in the adjuvant effect of aluminum and can direct a humoral adaptive immune response. In this review, we discuss the role of NLRs, and in particular the inflammasomes, in the recognition of microbial and danger components and the role they play in health and disease.

Autoinflammatory diseases

Autoinflammatory diseases (AIDs) are illnesses caused by primary dysfunction of the innate immune system. Proteins that are mutated in AIDs mediate the regulation of NFkappaB activation, cell apoptosis, and IL-1beta secretion through cross-regulated and sometimes common signaling pathways. AIDs include a broad number of monogenic [e.g., familial Mediterranean fever (FMF), cryopyrin-associated periodic syndrome (CAPS), mevalonate kinase deficiency (MKD), tumor necrosis factor (TNF)-receptor-associated periodic syndrome (TRAPS)] and multifactorial (e.g., Behçet's syndrome) disorders. These conditions are characterized by recurrent attacks of fever, abdominal pain, arthritis, and cutaneous signs; these symptoms sometimes overlap, obscuring diagnosis. Distinguishing signs and the use of specific functional tests where available (e.g., in MKD) are helpful. However, some patients remain hard to manage despite the advent of new genetic tests and/or due to lack of effective treatment.

NOD-like receptors and inflammation

The nucleotide-binding and oligomerization domain, leucine-rich repeat (also known as NOD-like receptors, both abbreviated to NLR) family of intracellular pathogen recognition receptors are increasingly being recognized to play a pivotal role in the pathogenesis of a number of rare monogenic diseases, as well as some more common polygenic conditions. Bacterial wall constituents and other cellular stressor molecules are recognized by a range of NLRs, which leads to activation of the innate immune response and upregulation of key proinflammatory pathways, such as IL-1beta production and translocation of nuclear factor-kappaB to the nucleus. These signalling pathways are increasingly being targeted as potential sites for new therapies. This review discusses the role played by NLRs in a variety of inflammatory diseases and describes the remarkable success to date of these therapeutic agents in treating some of the disorders associated with aberrant NLR function.

The infevers autoinflammatory mutation online registry: update with new genes and functions

Infevers (Internet Fevers; http://fmf.igh.cnrs.fr/ISSAID/infevers), a website dedicated to mutations responsible for hereditary autoinflammatory diseases, was created in 2002 and has continued to evolve. This new version includes eight genes; six were already present: MEFV, MVK, TNFRSF1A, NLRP3, NOD2, PSTPIP1, and two are new, LPIN2 and NLRP7. Currently, Infevers contains over 540 sequence variants. Several new database functions were recently instituted. The website now accepts confidential data and complex alleles. For each gene, a newly created menu offers: 1) a tabular list of the variants that can be sorted by several parameters; 2) a gene graph providing a schematic representation of the variants along the gene; 3) statistical analysis of the data according to the phenotype, alteration type, and location of the mutation in the gene; 4) the cDNA and gDNA sequences of each gene, showing the nucleotide changes along the sequence, with a color-based code highlighting the gene domains, the first ATG, and the termination codon; and 5) a "download" menu making all tables and figures available for the users, which, except for the gene graphs, are all automatically generated and updated upon submission of the variants. Finally, the entire database was curated to comply with the HUGO Gene Nomenclature Committee (HGNC) and HGVS nomenclature guidelines, and wherever necessary, an informative note was provided. Infevers has already proven useful for the scientific community with a mean number of visits per month of 200 in 2002 and 800 in 2007, and its new design will lead to a more comprehensive comparative analysis and interpretation of auto-inflammatory sequence variants.

Successful treatment of resistant pseudogout with anakinra

We describe herein the case of a 63-year-old man with pseudogout affecting multiple joints that was resistant to treatment with allopurinol, steroids, and antiinflammatory drugs. Based on recent data on the molecular mechanism of pseudogout that demonstrated overproduction of interleukin-1 (IL-1), we treated the patient with anakinra, an IL-1 receptor antagonist. The patient responded to treatment with anakinra within 2 weeks, with resolution of the signs and symptoms of pseudogout and normalization of levels of inflammation markers.

The familial Mediterranean fever (MEFV) gene may be a modifier factor of inflammatory bowel disease in infancy

Pediatric inflammatory bowel disease (IBD) usually manifests in childhood or adolescence, but a small number of cases present in infancy. Genetic factors are more important than environmental ones in the onset of pediatric IBD. We report here the concurrent manifestation of IBD and familial Mediterranean fever (FMF) in three infants (less than 6 months of age) in whom infantile ulcerative colitis (UC) was associated with the MEFV mutation. One patient required colectomy before the diagnosis of FMF, and in the other two patients, the UC could not be controlled until colchicine was added to the drug regimen. We suggest that the onset of UC in infants should prompt a search for MEFV mutations as this association may influence the management of the disease.

Primer: inflammasomes and interleukin 1beta in inflammatory disorders

Inflammasomes are large, multimeric protein complexes that link the sensing of microbial products and metabolic stress to the proteolytic processing of prointerleukin (pro-IL)-1beta to its active form. NALP1 and NALP2 are founding members of the Nod-like receptor family. Other Nod-like receptors, including NALP3 and NOD2, which are associated with inflammatory disorders, have also been described. The NALP1 and NALP3 inflammasomes are located in the cytoplasm and can, therefore, detect intracellular infection through recognition of microbial pathogen-associated molecular patterns. The inflammasome pathways cooperate with Toll-like receptor pathways to mediate a rapid and appropriate response to pathogens and genotoxic stress. Mutations in both pyrin and NALP3 components of inflammasomes are associated with innate-immune-mediated diseases (familial Mediterranean fever and the 'cryopyrinopathies'), and aberrant IL-1beta processing has been reported in several autoinflammatory conditions, including Muckle-Wells syndrome, chronic infantile neurologic, cutaneous and articular syndrome/neonatal onset multisystem inflammatory disease, and gout. The effectiveness of IL-1beta blockade in treating many of these conditions has transformed the understanding and management of these disorders and also highlighted the role of aberrant IL-1beta signaling in other conditions, such as adult-onset Still's disease and systemic juvenile idiopathic arthritis.

Roles of F-BAR/PCH proteins in the regulation of membrane dynamics and actin reorganization

The Pombe Cdc15 Homology (PCH) proteins have emerged in many species as important coordinators of signaling pathways that regulate actomyosin assembly and membrane dynamics. The hallmark of the PCH proteins is the presence of a Fes/CIP4 homology-Bin/Amphiphysin/Rvsp (F-BAR) domain; therefore they are commonly referred to as F-BAR proteins. The prototype F-BAR protein, Cdc15p of Schizosaccharomyces pombe, has a role in the formation of the contractile actomyosin ring during cytokinesis. Vertebrate F-BAR proteins have an established role in binding phospholipids and they participate in membrane deformations, for instance, during the internalization of transmembrane receptors. This way the F-BAR proteins will function as linkers between the actin polymerization apparatus and the machinery regulating membrane dynamics. Interestingly, some members of the F-BAR proteins are implicated in inflammatory or neurodegenerative disorders and the observations can be expected to have clinical implications for the treatment of the diseases.

Autoinflammatory syndromes with a dermatological perspective

The term autoinflammatory syndromes describes a distinct group of systemic inflammatory diseases apparently different from infectious, autoimmune, allergic and immunodeficient ones. Originally, it was almost synonymous with clinically defined hereditary periodic fever syndromes, including familial Mediterranean fever, hyper immunoglobulin D syndrome with periodic fever and tumor necrosis factor receptor-associated periodic syndrome. Similar but distinct periodic fever syndromes accompanied by urticarial rash, familial cold autoinflammatory syndrome, Muckle-Wells syndrome and chronic infantile neurological cutaneous articular syndrome, have all been reportedly associated with CIAS1 mutations and are collectively called cryopyrin-associated periodic syndromes. Consequently, the concept of autoinflammatory syndromes has been spread to contain other systemic inflammatory diseases: rare hereditary diseases with or without periodic fevers, such as pyogenic sterile arthritis, pyoderma gangrenosum and acne syndrome, Blau syndrome and chronic recurrent multifocal osteomyelitis, and the more common collagen disease-like diseases, such as Behcet's disease, Crohn's disease, sarcoidosis and psoriatic arthritis. These diseases are all caused by or associated with mutations of genes regulating innate immunity and have common clinical features accompanied with activation of neutrophils and/or monocytes/macrophages. In this review, major autoinflammatory syndromes are summarized and the pathophysiology of related skin disorders is discussed in association with dysregulated innate immune signaling.

The NLR network and the immunological disease continuum of adaptive and innate immune-mediated inflammation against self

The nucleotide-binding domain, leucine-rich repeat containing family (NLR) network has provided pivotal genetic and molecular insights into diseases that were hitherto regarded as autoimmune. The NLR-related disorders include rare monogenic autoinflammatory diseases collectively termed cryopyrin-associated periodic syndromes, Crohn's disease which is a common polygenic disease and also an association at the mechanistic level with gout and pseudogout. Unlike the classical autoimmune diseases where disease immunopathogenesis is played out primarily in the primary and secondary lymphoid organs, the immunopathogenesis of the NLR-related disorders is played out in the tissues where inflammation arises. As the genetic mutations or molecular cascades associated with the NLR-related disorders have a widespread cellular distribution, it has been somewhat enigmatic why these disorders attack certain territories, but not others. This implies that tissue-specific factors in the target organs themselves contribute to disease expression. Such examples include the high abundance of NOD2 expressing cells in the part of the gut most typically afflicted by Crohn's disease and the preferential deposition of crystals in the joints to where inflammation localises in gout and pseudogout. The NLR network is associated principally with increases in TNF or IL-1 production, both of which are key players in innate immunity. Therefore, the NLR network identifies at the genetic and molecular level a robust paradigm for innate immune activation against self. This tissue-specific-factor-associated inflammation is the diametric opposite of classical autoimmunity. Of note, the MHC class-I-associated diseases including psoriasis (HLA-Cw6) and ankylosing spondylitis (HLA-B27) show striking clinical overlaps with Crohn's disease and also some rare monogenic diseases. Thus, the NLR innate immune pathway allows the full spectrum of inflammation against self to be viewed along an immunological disease continuum with autoantibody-associated disease at one end, innate immune diseases at the other and MHC class-1-related disorders as an intermediate.

Pombe Cdc15 homology proteins: regulators of membrane dynamics and the actin cytoskeleton

Pombe Cdc15 homology (PCH) proteins have emerged in many species as important coordinators of signalling pathways that regulate actomyosin assembly and membrane dynamics. For example, the prototype PCH protein, Cdc15p of Schizosaccharomyces pombe, has a role in assembly of the contractile ring, which is needed to separate dividing cells. Recently, mammalian PCH proteins have been found to bind phospholipids and to participate in membrane deformation. These findings suggest that PCH proteins are crucial linkers of membrane dynamics and actin polymerization, for example, during the internalization of transmembrane receptors. Intriguingly, some members of the PCH protein family are mutated in neurodegenerative and inflammatory diseases, which has implications for the identification of cures for such disorders.

A proposed classification of the immunological diseases

The formal recognition and genetic understanding of the autoinflammatory diseases has defined mechanisms of self-directed inflammation that are independent of adaptive immunity.

Hereditary auto-inflammatory disorders and biologics

The term auto-inflammatory disorders has been coined to describe a group of conditions characterized by spontaneously relapsing and remitting bouts of systemic inflammation without apparent involvement of antigen-specific T cells or significant production of auto-antibodies. The hereditary periodic fever syndromes are considered as the prototypic auto-inflammatory diseases, and genetic studies have yielded important new insights into innate immunity. DNA analysis has greatly enhanced the clinical characterization of these conditions, and elucidation of their molecular aetiopathogenesis has suggested that therapies may be aimed at specific targets within the immune cascade. The availability of biologic response modifiers such as inhibitors of tumour necrosis factor (TNF) and interleukin-1beta has greatly improved the outlook for some of these disorders, although effective therapies remain elusive in patients with certain conditions, including hyperimmunoglobulinaemia-D with periodic fever syndrome (HIDS) and a proportion of those with TNF-receptor associated periodic syndrome (TRAPS). Indeed, outstanding challenges and the unique potential to further elucidate molecular mechanisms in innate immunity are illustrated by the dashed early hope that TNF blockade would be a panacea for TRAPS: not only is etanercept (Enbrel) ineffective in some cases, but there are anecdotal reports of this condition being greatly exacerbated by infliximab (Remicade).

Mutation of mouse Mayp/Pstpip2 causes a macrophage autoinflammatory disease

Macrophage actin-associated tyrosine phosphorylated protein (MAYP)/PSTPIP2, a PCH protein, is involved in the regulation of macrophage motility. Mutations in a closely related gene, PSTPIP1/CD2BP1, cause a dominantly inherited autoinflammatory disorder known as PAPA syndrome. A mutant mouse obtained by chemical mutagenesis exhibited an autoinflammatory disorder characterized by macrophage infiltration and inflammation, leading to osteolysis and necrosis in paws and necrosis of ears. Positional cloning of this recessive mutation, termed Lupo, identified a T to A nucleotide exchange leading to an amino acid substitution (I282N) in the sequence of MAYP. Mayp(Lp/Lp) disease was transferable by bone marrow transplantation and developed in the absence of lymphocytes. Consistent with the involvement of macrophages, lesion development could be prevented by the administration of clodronate liposomes. MAYP is expressed in monocytes/macrophages and in a Mac1+ subfraction of granulocytes. LPS stimulation increases its expression in macrophages. Because of the instability of the mutant protein, MAYP expression is reduced 3-fold in Mayp(Lp/Lp) macrophages and, on LPS stimulation, does not rise above the level of unstimulated wild-type (WT) cells. Mayp(Lp/Lp) mice expressed elevated circulating levels of several cytokines, including MCP-1; their macrophages exhibited altered cytokine production in vitro. These studies suggest that MAYP plays an anti-inflammatory role in macrophages.

Increased frequency of mutations in the gene responsible for familial Mediterranean fever (MEFV) in a cohort of patients with ulcerative colitis: evidence for a potential disease-modifying effect?

The MEFV gene, responsible for familial Mediterranean fever (FMF), is involved in inflammatory reactions through altered leukocyte apoptosis, secretion of interleukin (IL)-1beta, and activation of the NF-kappa B pathway. Ulcerative Colitis (UC) and FMF are both characterized by a recurrent pattern of presentation with periods of remission and flares associated with neutrophilic infiltration at the site of injury. The aim of this study was to investigate the possible correlation between UC and MEFV gene alterations. Twenty-five consecutive, first-diagnosed and untreated UC patients, 28 control patients with rheumatoid arthritis, and 65 normal individuals were analyzed. Nonisotopic RNase Cleavage Assay (NIRCA) was applied as a first-step mutational screening method of exons 10 and 2 of MEFV gene; direct sequencing was subsequently performed to confirm the results. MEFV mutations were identified in 7 (3 M694V/0, 2 M680I/0, 1 E148Q/E148Q, and 1 A744S/0) out of 25 UC patients versus 1 (M694V/0) out of 28 rheumatoid arthritis patients (P = .0199) and 1 (M694V/0) out of 65 healthy controls (P = .0004). Four out of 7 patients with MEFV mutations had inflammatory arthritis, a clinical finding that was not observed in the 18 UC patients with unmutated MEFV (P = .0028). Patients with UC almost universally carried the T A C G MEFV exon 2 haplotype in contrast with normal individuals (P < .0001) and FMF patients (P = .0310). In conclusion the increased frequency of mutations of MEFV in UC patients, especially in those with episodic arthritis, suggests a possible modifying effect of MEFV in the disease process and its localization within the joint. The difference in distribution of MEFV exon 2 haplotypes between UC patients and both FMF patients and normal individuals, suggests that UC patients constitute a genetically distinct population. Larger, longitudinal studies are needed to confirm these initial findings.

Cryopyrin and pyrin activate caspase-1, but not NF-kappaB, via ASC oligomerization

Mutations in cryopyrin and pyrin proteins are responsible for several autoinflammatory disorders in humans, suggesting that these proteins play important roles in regulating inflammation. Using a HEK293 cell-based reconstitution system that stably expresses ASC and procaspase-1 we demonstrated that neither cryopyrin nor pyrin or their corresponding disease-associated mutants could significantly activate NF-kappaB in this system. However, both cryopyrin and two disease-associated cryopyrin mutants induced ASC oligomerization and ASC-dependent caspase-1 activation, with the disease-associated mutants being more potent than the wild-type (WT) cryopyrin, because of increased self-oligomerization. Contrary to the proposed anti-inflammatory activity of WT pyrin, our results demonstrated that pyrin, like cryopyrin, can also assemble an inflammasome complex with ASC and procaspase-1 leading to ASC oligomerization, caspase-1 activation and interleukin-1beta processing. Thus, we propose that pyrin could function as a proinflammatory molecule.

A probable case of Muckle-Wells syndrome

Muckle-Wells syndrome is a rare autosomally dominant disorder belonging to the group of periodic fever syndromes. Three main features of the disease are: (i) urticarial eruptions; (ii) progressive perceptive deafness; and (iii) amyloid nephropathy. A 26-year-old Japanese woman had suffered at birth from an urticarial rash and episodic fever. The fever was frequently associated with chills and ill-defined malaise. There was no familial history of urticarial rash or fever. Although she did not recognize hearing loss, audiometry revealed perceptive deafness. She also had hepatosplenomegaly and hyperimmunoglobulinemia, but did not have persistent arthritis, or any neurological or gastrointestinal disorder. No growth retardation was observed. Skin biopsy specimens from her buttock showed a sparse perivascular and interstitial infiltrate of neutrophils in the papillary dermis. Periodic fever syndrome was diagnosed. Muckle-Wells syndrome was most likely, although no amyloid nephropathy was observed and no gene mutations of CIAS1 (T785C, C778T, G907A, G1315A, G1075C) were detected. We treated her with prednisolone, which had a partial effect. Previous treatment with colchicines, antihistamines, dapsone, clarithromycin, minocycline hydrochloride and loxoprofen sodium had been unsuccessful. Muckle-Wells syndrome may go undiagnosed for many years or be misdiagnosed as refractory urticaria. Therefore, we should consider the possibility of periodic fever syndrome when we see patients with refractory urticaria and episodic fever.

Distinguishing among prolonged, recurrent, and periodic fever syndromes: approach of a pediatric infectious diseases subspecialist

Most children with prolonged, recurrent, or periodic fever are healthy and have self-limited, common illnesses, and the primary care practitioner usually can reassure families and continue to reassess the patient as circumstances dictate. For a child with true fever of unknown origin, a pediatric infectious diseases subspecialist should be consulted. This article discusses three objectives for the clinician: (1) to categorize patterns of fever illnesses and prioritize differential diagnoses; (2) to diagnose and manage the most frequently encountered prolonged fever syndrome, deconditioning; and (3) to expand knowledge and approach to diagnosing periodic fever syndromes. The approach described in this article represents the honed, 30-year experience of a pediatric infectious diseases subspecialist.