Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) is a disorder of innate immunity and Th1 activation responsive to IL-1 blockade. Proc Natl Acad Sci U S A. 2011;108:7148-7153. [PMID: 21478439 DOI: 10.1073/pnas.1103681108]

Family History in Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA) Syndrome

OBJECTIVE

The goal of this study was to describe family history and inheritance patterns in patients with periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis (PFAPA) syndrome.

METHODS

We performed a case-control study to compare the family histories of patients with PFAPA recruited from Vanderbilt University Medical Center and matched healthy control subjects from a pediatric primary care practice in Nashville, Tennessee, by using a structured questionnaire. Characteristics of paired case subjects, control subjects, and their family members were compared by using McNemar's test and Wilcoxon signed-rank tests.

RESULTS

Eighty PFAPA index case subjects and 80 control subjects were recruited. Eighteen PFAPA case subjects (23%) had ≥1 family member with PFAPA. Parents of PFAPA index case subjects were more likely to have recurrent pharyngitis (36% vs 16%; P < .001) and recurrent aphthous stomatitis (46% vs 28%; P = .002) compared with parents of control subjects. Siblings of case subjects had a higher prevalence of PFAPA (10% vs 2%; P = .04), recurrent pharyngitis (24% vs 10%; P = .03), and recurrent aphthous stomatitis (27% vs 7%; P = .003) compared with siblings of control subjects.

CONCLUSIONS

A portion of PFAPA case subjects seems to be familial, implying an inherited genetic predisposition to the disorder and/or shared environmental exposures. First-degree relatives (parents and siblings) of patients with PFAPA have a higher prevalence of recurrent pharyngitis and aphthous stomatitis than relatives of control subjects, which suggests that these disorders represent reduced penetrance phenotypes of PFAPA. Further characterization of the genetics and inflammatory profiles of these patients and their relatives is warranted.

Induction of Myeloid-Derived Suppressor Cells in Cryopyrin-Associated Periodic Syndromes

Cryopyrin-associated periodic syndromes (CAPS) are caused by mutations in the NLRP3 gene leading to overproduction of IL-1β and other NLRP3 inflammasome products. Myeloid-derived suppressor cells (MDSCs) represent a novel innate immune cell subset capable of suppressing T-cell responses. As inflammasome products were previously found to induce MDSCs, we hypothesized that NLRP3 inflammasome-dependent factors induce the generation of MDSCs in CAPS. We studied neutrophilic MDSCs, their clinical relevance, and MDSC-inducing factors in a unique cohort of CAPS patients under anti-IL-1 therapy. Despite anti-IL-1 therapy and low clinical disease activity, CAPS patients showed significantly elevated MDSCs compared to healthy controls. MDSCs were functionally competent, as they suppressed polyclonal T-cell proliferation, as well as Th1 and Th17 responses. In addition, MDSCs decreased monocytic IL-1β secretion. Multiplex assays revealed a distinct pattern of MDSC-inducing cytokines, chemokines, and growth factors. Experimental analyses demonstrated that IL-1 cytokine family members and autoinflammation-associated alarmins differentially induced human MDSCs. Increased MDSCs might represent a novel autologous anti-inflammatory mechanism in autoinflammatory conditions and may serve as a future therapeutic target.

PFAPA syndrome: a review on treatment and outcome

The syndrome of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA syndrome) is the most common cause of periodic fever in childhood. The current pharmacological treatment includes corticosteroids, which usually are efficacious in the management of fever episodes, colchicine, for the prophylaxis of febrile episodes, and other medication for which efficacy has not been proven so far. Tonsillectomy is an option for selected patients. Usually PFAPA syndrome resolves during adolescence, but there is increasing evidence that this condition may persist into adulthood.

Guidelines for the management and treatment of periodic fever syndromes: periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome

OBJECTIVE

To establish guidelines based on scientific evidence for the management of periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome.

DESCRIPTION OF THE EVIDENCE COLLECTION METHOD

The Guideline was prepared from 5 clinical questions that were structured through PICO (Patient, Intervention or indicator, Comparison and Outcome), to search in key primary scientific information databases. After defining the potential studies to support the recommendations, these were graduated considering their strength of evidence and grade of recommendation.

RESULTS

806 articles were retrieved and evaluated by title and abstract; from these, 32 articles were selected to support the recommendations.

RECOMMENDATIONS

1. PFAPA is a diagnosis of exclusion established on clinical grounds, and one must suspect of this problem in children with recurrent and periodic febrile episodes of unknown origin, or with recurrent tonsillitis interspersed with asymptomatic periods, especially in children in good general condition and with preservation of weight and height development. 2. Laboratory findings are nonspecific. Additional tests do not reveal pathognomonic changes. 3. The evidence supporting an indication for surgical treatment (tonsillectomy with or without adenoidectomy), is based on two non-blinded randomized clinical trials with small numbers of patients. 4. The use of prednisone at the onset of fever in patients with PFAPA proved to be an effective strategy. There is still need for more qualified evidence to support its use in patients with PFAPA. 5. Despite promising results obtained in studies with IL-1β inhibitors, such studies are limited to a few case reports.

Recurrent Fevers for the Pediatric Immunologist: It's Not All Immunodeficiency

Autoinflammatory diseases are disorders of the innate immune system, characterized by systemic inflammation independent of infection and autoreactive antibodies or antigen-specific T cells. Similar to immunodeficiencies, these immune dysregulatory diseases have unique presentations, genetics, and available therapies. Given the presentation of fevers, rashes, and mucosal symptoms in many of the disorders, the allergist/immunologist is the appropriate medical home for these patients: to appropriately rule out immunodeficiencies, evaluate for allergic disease, and diagnose and treat recurrent fever disorders. However, many practicing physicians are unfamiliar with the clinical presentation, diagnosis, and treatment of autoinflammatory disorders. This review will focus on understanding the signs and symptoms of classic autoinflammatory disorders, introduce newly described monogenic and polygenic disorders, and address the approach to the patient with recurrent fevers to distinguish autoinflammation from immunodeficiency and autoimmunity.

Multiple Serum Cytokine Profiling to Identify Combinational Diagnostic Biomarkers in Attacks of Familial Mediterranean Fever

The precise cytokine networks in the serum of individuals with familial Mediterranean fever (FMF) that are associated with its pathogenesis have been unknown. Here, we attempted to identify specific biomarkers to diagnose or assess disease activity in FMF patients. We measured serum levels of 45 cytokines in 75 FMF patients and 40 age-matched controls by multisuspension cytokine array. FMF in "attack" or "remission" was classified by Japan College of Rheumatology-certified rheumatologists according to the Tel Hashomer criteria. Cytokines were ranked by their importance by a multivariate classification algorithm. We performed a logistic regression analysis to determine specific biomarkers for discriminating FMF patients in attack. To identify specific molecular networks, we performed a cluster analysis of each cytokine. Twenty-nine of the 45 cytokines were available for further analyses. Eight cytokines' serum levels were significantly elevated in the FMF attack versus healthy control group. Nine cytokines were increased in FMF attack compared to FMF remission. Multivariate classification algorithms followed by a logistic regression analysis revealed that the combined measurement of IL-6, IL-18, and IL-17 distinguished FMF patients in attack from the controls with the highest accuracy (sensitivity 89.2%, specificity 100%, and accuracy 95.5%). Among the FMF patients, the combined measurement of IL-6, G-CSF, IL-10, and IL-12p40 discriminated febrile attack periods from remission periods with the highest accuracy (sensitivity 75.0%, specificity 87.9%, and accuracy 84.0%). Our data identified combinational diagnostic biomarkers in FMF patients based on the measurement of multiple cytokines. These findings help to improve the diagnostic performance of FMF in daily practice and extend our understanding of the activation of the inflammasome leading to enhanced cytokine networks.

Anti-interleukin 1 treatment in secondary amyloidosis associated with autoinflammatory diseases

BACKGROUND

Amyloidosis may complicate autoinflammatory diseases (AID). We aimed to evaluate the renal biopsy findings, and clinical and laboratory parameters in patients with AID-associated amyloidosis who have responded to anti-interleukin 1(IL1) treatment.

METHODS

Two children with systemic juvenile idiopathic arthritis and one with cryopyrin-associated periodic syndrome diagnosed as having reactive amyloidosis were treated with anti-IL1 drugs. The renal histopathological findings at the time of diagnosis of amyloidosis and after the onset of anti-IL1 were evaluated according to the amyloid scoring/grading system.

RESULTS

The median age of disease onset and diagnosis of amyloidosis were 3 and 12 years, respectively. Anakinra was started in all; however, anakinra caused a local cutaneous reaction in one, thus canakinumab was commenced. Proteinuria improved in all. Control renal biopsies were performed a median of 3 years after the first biopsies. The renal amyloid prognostic score did not improve in patient 1, and progressed in patients 2 and 3. The renal amyloid grade progressed in patient 2.

CONCLUSIONS

This is the first series demonstrating progression of renal tissue damage after the improvement of proteinuria with anti-IL 1 in AID-associated amyloidosis. Anti-IL1 drugs are important to prevent further amyloid accumulation; however, new treatment strategies are needed to target the amyloid deposits.

Tonsillar microbiota in children with PFAPA (periodic fever, aphthous stomatitis, pharyngitis, and adenitis) syndrome

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) is a childhood febrile syndrome of unknown origin that is often cured with tonsillectomy. We aimed to compare the bacterial microbiota of the tonsils removed from PFAPA patients with those of controls. We used next-generation sequencing technology to investigate the bacterial microbiota of the tonsils of 30 PFAPA patients and 24 controls. We found significant differences in the presence and relative abundance of many bacteria between PFAPA cases and controls. For example, cyanobacteria, potential producers of microcystins and other toxins, were more common in the case samples (14/30, 47 %) than in the controls (4/24, 17 %, p = 0.02), and the mean relative abundance of cyanobacteria was higher in the case samples (0.2 %) than in the controls (0.01 %, p = 0.01). Streptococci were present in all samples in both groups, but their mean relative abundance was lower in the case samples (3.7 %) than in the controls (9.6 %, p = 0.01). Typical nasopharyngeal microbes such as fusobacteria, Prevotella, Tannerella, Porphyromonas, and Parvimonas dominated the microbiota of the tonsils in both groups. The microbiota of the tonsils removed from PFAPA patients differed significantly from those of the controls. Tonsillar microbiota may play a role in triggering the inflammatory processes that lead to symptoms of PFAPA.

Procalcitonin and C-reactive protein-based decision tree model for distinguishing PFAPA flares from acute infections

As no specific laboratory test has been identified, PFAPA (periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis) remains a diagnosis of exclusion. We searched for a practical use of procalcitonin (PCT) and C-reactive protein (CRP) in distinguishing PFAPA attacks from acute bacterial and viral infections. Levels of PCT and CRP were measured in 38 patients with PFAPA and 81 children diagnosed with an acute bacterial (n=42) or viral (n=39) infection. Statistical analysis with the use of the C4.5 algorithm resulted in the following decision tree: viral infection if CRP≤19.1 mg/L; otherwise for cases with CRP>19.1 mg/L: bacterial infection if PCT>0.65ng/mL, PFAPA if PCT≤0.65 ng/mL. The model was tested using a 10-fold cross validation and in an independent test cohort (n=30), the rule’s overall accuracy was 76.4% and 90% respectively. Although limited by a small sample size, the obtained decision tree might present a potential diagnostic tool for distinguishing PFAPA flares from acute infections when interpreted cautiously and with reference to the clinical context.

The Pathogenesis of Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis Syndrome: A Review of Current Research

Background. PFAPA syndrome is a chronic disease that is characterized by recurrent episodes of high fever, aphthous stomatitis, pharyngitis, and cervical adenitis. Knowledge regarding the etiology of PFAPA is limited. Objectives. To provide up-to-date information considering etiology of PFAPA syndrome, by summarizing what has been explored and established in this area so far. Materials and Methods. PubMed, Web of Science, and Scopus databases were searched for pertinent reports. Eventually 19 articles were selected. The results were classified into categories regarding three areas of interest: familial occurrence, genetic basis, and immunological mechanisms of PFAPA. Results. Recent findings suggest that there is a familial tendency to PFAPA but the level of evidence does not warrant definite conclusions. The absence of a clear monogenic trait indicates a heterogenous, polygenic, or complex inheritance of PFAPA syndrome. As two mutations with a possible functional effect on the inflammasomes (MEFV E148Q and NLRP3 Q703K) have been found in several PFAPA cohorts, the role of inflammasome-related genes in PFAPA pathogenesis cannot be excluded. Immunological mechanisms of PFAPA involve an abnormal, IL-1β dependent innate immune response to an environmental trigger, which leads to Th1-driven inflammation expressed by recruitment of T-cells to the periphery.

Practice parameter for the diagnosis and management of primary immunodeficiency

The American Academy of Allergy, Asthma & Immunology (AAAAI) and the American College of Allergy, Asthma & Immunology (ACAAI) have jointly accepted responsibility for establishing the "Practice parameter for the diagnosis and management of primary immunodeficiency." This is a complete and comprehensive document at the current time. The medical environment is a changing environment, and not all recommendations will be appropriate for all patients. Because this document incorporated the efforts of many participants, no single individual, including those who served on the Joint Task Force, is authorized to provide an official AAAAI or ACAAI interpretation of these practice parameters. Any request for information about or an interpretation of these practice parameters by the AAAAI or ACAAI should be directed to the Executive Offices of the AAAAI, the ACAAI, and the Joint Council of Allergy, Asthma & Immunology. These parameters are not designed for use by pharmaceutical companies in drug promotion.

Basic Characteristics of Adults with Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenopathy Syndrome in Comparison with the Typical Pediatric Expression of Disease

Autoinflammatory diseases are caused by inflammasome dysregulation leading to overproduction of proinflammatory cytokines and a pathological delay in the inflammation switching off. The progress of cellular biology has partially clarified pathogenic mechanisms behind monogenic autoinflammatory diseases, whereas little is known about the polygenic ones. Although the genetic susceptibility of periodic fever, aphthous stomatitis, pharyngitis, and adenopathy (PFAPA) syndrome is still obscure, the presence of overlapping symptoms with monogenic periodic fevers, the recurrence in family members, the important role played by dysregulated interleukin- (IL-) 1β secretion during flares, the overexpression of inflammasome-associated genes during attacks, and, last but not least, the therapeutic efficacy of IL-1β blockade strongly indicate a potential genetic involvement in its pathogenesis, probably linked with environmental factors. PFAPA syndrome has a typical inception in the pediatric age, but a delayed onset during adulthood has been described as well. Treatments required as well as effectiveness of tonsillectomy remain controversial, even if the disease seems to have a self-limited course mostly in children. The purpose of this review is to provide an overview of this complex polygenic/multifactorial autoinflammatory disorder in which the innate immune system undoubtedly plays a basic role.

From bench to bedside and back again: translational research in autoinflammation

Translational research approaches brought major changes to the understanding and treatment options of autoinflammatory diseases. Patients with common complex multifactorial diseases such as systemic-onset juvenile idiopathic arthritis (sJIA), and particularly those with rare monogenic autoinflammatory diseases such as cryopyrin-associated periodic syndromes (CAPS) or TNF receptor-associated periodic syndrome (TRAPS), benefited from a deeper understanding of the pathophysiological mechanisms and new treatment options emerging from preclinical studies. The study of IL-1 and IL-6 in this context led to novel therapies by forward translation. Conversely, effective treatment of sJIA and TRAPS with IL-1 blockade stimulated reverse translational efforts to study the pathophysiology of these cytokines in autoinflammatory diseases. These translational efforts led to the discovery of biomarkers such as S100 proteins, IL-18 or serum amyloid A, which are components of the inflammatory process, support diagnosis and allow for monitoring of disease activity, helping to predict patient outcomes. The ongoing characterization of autoinflammatory diseases in individual patients has led to classification into heterogeneous subgroups. Further characterization of relevant subgroups and the design of tailored treatment regimens, as well as the identification of new therapeutic targets and treatment options, are the major future challenges in the field of autoinflammatory diseases, particularly for paediatric rheumatologists.

Analysis of the genetic basis of periodic fever with aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome

PFAPA syndrome is the most common autoinflammatory syndrome in children from Western countries. In spite of its strong familial clustering, its genetic basis and inheritance pattern are still unknown. We performed a comprehensive genetic study on 68 individuals from 14 families. Linkage analysis suggested a susceptibility locus on chromosome 8, but direct molecular sequencing did not support this initial statistical finding. Exome sequencing revealed the absence of any gene that was mutated in all patients. Exhaustive screening of genes involved in other autoinflammatory syndromes or encoding components of the human inflammasome showed no DNA variants that could be linked to PFAPA molecular pathology. Among these, the previously-reported missense mutation V198M in the NLRP3 gene was clearly shown not to co-segregate with PFAPA. Our results on this relatively large cohort indicate that PFAPA syndrome is unlikely to be a monogenic condition. Moreover, none of the several genes known to be involved in inflammation or in autoinflammatory disorders seem to be relevant, alone, to its etiology, suggesting that PFAPA results from oligogenic or complex inheritance of variants in multiple disease genes and/or non-genetic factors.

Clinical features and genetic background of the periodic Fever syndrome with aphthous stomatitis, pharyngitis, and adenitis: a single center longitudinal study of 81 patients

PFAPA syndrome is the most common autoinflammatory disorder in childhood with unknown etiology. The aim of our study was clinical evaluation of PFAPA patients from a single tertiary care center and to determine whether variations of AIM2, MEFV, NLRP3, and MVK genes are involved in PFAPA pathogenesis. Clinical and laboratory data of consecutive patients with PFAPA syndrome followed up at the University Children's Hospital, Ljubljana, were collected from 2008 to 2014. All four genes were PCR amplified and directly sequenced. Eighty-one patients fulfilled criteria for PFAPA syndrome, 50 (63%) boys and 31 (37%) girls, with mean age at disease onset of 2.1 ± 1.5 years. Adenitis, pharyngitis, and aphthae were present in 94%, 98%, and 56%, respectively. Family history of recurrent fevers in childhood was positive in 78%. Nineteen variants were found in 17/62 (27%) patients, 4 different variants in NLRP3 gene in 13 patients, and 6 different variants in MEFV gene in 5 patients, and 2 patients had 2 different variants. No variants of clinical significance were found in MVK and AIM2 genes. Our data suggest that PFAPA could be the result of multiple low-penetrant variants in different genes in combination with epigenetic and environmental factors leading to uniform clinical picture.

Interleukin-1 as a common denominator from autoinflammatory to autoimmune disorders: premises, perils, and perspectives

A complex web of dynamic relationships between innate and adaptive immunity is now evident for many autoinflammatory and autoimmune disorders, the first deriving from abnormal activation of innate immune system without any conventional danger triggers and the latter from self-/non-self-discrimination loss of tolerance, and systemic inflammation. Due to clinical and pathophysiologic similarities giving a crucial role to the multifunctional cytokine interleukin-1, the concept of autoinflammation has been expanded to include nonhereditary collagen-like diseases, idiopathic inflammatory diseases, and metabolic diseases. As more patients are reported to have clinical features of autoinflammation and autoimmunity, the boundary between these two pathologic ends is becoming blurred. An overview of monogenic autoinflammatory disorders, PFAPA syndrome, rheumatoid arthritis, type 2 diabetes mellitus, uveitis, pericarditis, Behçet's disease, gout, Sjögren's syndrome, interstitial lung diseases, and Still's disease is presented to highlight the fundamental points that interleukin-1 displays in the cryptic interplay between innate and adaptive immune systems.

PFAPA syndrome and Behçet's disease: a comparison of two medical entities based on the clinical interviews performed by three different specialists

The pediatric syndrome characterized by periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) and adult Behçet's disease share some clinical manifestations and are both polygenic autoinflammatory disorders with interleukin-1β showing to play a pivotal role. However, the diagnosis is mostly clinical and we hypothesize that specific criteria may be addressed differently by different physicians. To determine the diagnostic variability, we compared the answers of 80 patients with a definite diagnosis of Behçet's disease (age 42.1 ± 13.7 years) obtained by separate telephone interviews conducted by a rheumatologist, a pediatrician, and an internist working largely in the field of autoinflammatory disorders. Questions were related to the age of symptom onset, the occurrence of recurrent fevers during childhood, and the association with oral aphthosis, cervical adenitis and/or pharyngitis, previous treatments, possible growth impairment, the time lapse between PFAPA-like symptoms and the onset of Behçet's disease, and the occurrence of Behçet-related manifestation during childhood. The rheumatologist identified 30 % of patients with Behçet's disease fulfilling PFAPA syndrome diagnostic criteria, compared to the pediatrician and the internist identifying 10 and 7.5 %, respectively. Most of the patients suffered from recurrent oral aphthosis in childhood also without fever (50, 39, and 48 % with each interviewer), yet no patient fulfilled the Behçet's disease diagnostic criteria. Our data suggest that physician awareness and expertise are central to the diagnosis of autoinflammatory disorders through an accurate collection of the medical history.

Polyclonal, newly derived T cells with low expression of inhibitory molecule PD-1 in tonsils define the phenotype of lymphocytes in children with Periodic Fever, Aphtous Stomatitis, Pharyngitis and Adenitis (PFAPA) syndrome

PURPOSE

PFAPA syndrome is a benign, recurrent inflammatory disease of childhood. Tonsillectomy is one of the therapeutic options with a yet unexplained biological mechanism. We tested whether specific lymphocyte subsets recruited from blood to human tonsils participate in PFAPA pathogenesis.

METHODS

Paired tonsils/peripheral blood (PB) samples were investigated (a) from children with PFAPA that successfully resolved after tonsillectomy (n=10) (b) from children with obstructive sleep apnoea syndrome as controls (n=10). The lymphocyte profiles were analysed using 8-colour flow cytometry, immunoglobulin (IGH) and T-cell receptor (TCR) gene rearrangements via PCR and next generation sequencing; a TREC/KREC analysis was performed using qPCR.

RESULTS

The PFAPA tonsils in the asymptomatic phase had a lower percentage of B-lymphocytes than controls; T-lymphocyte counts were significantly higher in PB. The percentages of cytotoxic CD8pos T-lymphocytes were approximately 2-fold higher in PFAPA tonsils; the transitional B cells and naïve stages of both the CD4pos and CD8pos T-lymphocytes with a low expression of PD-1 molecule and high numbers of TREC were also increased. With the exception of elevated plasmablasts, no other differences were significant in PB. The expression levels of CXCL10, CXCL9 and CCL19 genes were significantly higher in PFAPA tonsils. The IGH/TCR pattern showed no clonal/oligoclonal expansion. DNA from the Epstein-Barr virus, Human Herpervirus-6 or adenovirus was detected in 7 of 10 PFAPA tonsils but also in 7 of 9 controls.

CONCLUSIONS

Our findings suggest that the uninhibited, polyclonal response of newly derived lymphocytes participate in the pathogenesis of PFAPA. Because most of the observed changes were restricted to tonsils and were not present in PB, they partly explain the therapeutic success of tonsillectomy in PFAPA syndrome.

An expanding role for interleukin-1 blockade from gout to cancer

There is an expanding role for interleukin (IL)-1 in diseases from gout to cancer. More than any other cytokine family, the IL-1 family is closely linked to innate inflammatory and immune responses. This linkage is because the cytoplasmic segment of all members of the IL-1 family of receptors contains a domain, which is highly homologous to the cytoplasmic domains of all toll-like receptors (TLRs). This domain, termed "toll IL-1 receptor (TIR) domain," signals as does the IL-1 receptors; therefore, inflammation due to the TLR and the IL-1 families is nearly the same. Fundamental responses such as the induction of cyclo-oxygenase type 2, increased surface expression of cellular adhesion molecules and increased gene expression of a broad number of inflammatory molecules characterizes IL-1 signal transduction as it does for TLR agonists. IL-1β is the most studied member of the IL-1 family because of its role in mediating autoinflammatory disease. However, a role for IL-1α in disease is being validated because of the availability of a neutralizing monoclonal antibody to human IL-1α. There are presently three approved therapies for blocking IL-1 activity. Anakinra is a recombinant form of the naturally occurring IL-1 receptor antagonist, which binds to the IL-1 receptor and prevents the binding of IL-1β as well as IL-1α. Rilonacept is a soluble decoy receptor that neutralizes primarily IL-1β but also IL-1α. Canakinumab is a human monoclonal antibody that neutralizes only IL-1β. Thus, a causal or significant contributing role can be established for IL-1β and IL-1α in human disease.

An update on autoinflammatory diseases

Autoinflammatory diseases area group of clinical conditions other than autoimmune diseases, characterized by recurrent inflammatory episodes. From apathogenetic point of view they are determined by a dys regulation of innate immunity, without involvement of specific immunity (auto reactive T cells and auto antibodies). Recently, the increased knowledge in the field of auto inflammation highlighted shared immune mechanisms in the pathogenesis of both classical monogenetic and multifactorial auto inflammatory diseases and a broad spectrum of chronic age-related inflammatory pathologies. The current increase in the prevalence of chronic inflammatory diseases makes this subject of topical interest. In the light of these considerations, we propose an update of auto inflammatory diseases and a new interpretation of auto inflammation with both theoretical and clinical implications.

IL-18 gene polymorphisms in aphthous stomatitis vs. Behçet's disease in a cohort of Egyptian patients

OBJECTIVE

A clinical investigation of the potential correlation of two single-nucleotide polymorphisms at -137 (G/C) and -607 (C/A) in the promoter region of the IL-18 gene, with the susceptibility to aphthous stomatitis and Behçet's disease.

PATIENT AND METHODS

This study included 80 aphthous stomatitis patients and 80 patients with Behçet's disease. Eighty healthy subjects were enrolled as a control group. IL-18 single-nucleotide polymorphisms at -607 and -137 regions were analyzed using polymerase chain reaction-restriction fragment length polymorphism analysis.

RESULTS

The genotype and allele distributions of the two regions did not differ significantly between patients with aphthous stomatitis and controls. The genotype and allele distributions at -607 were significantly different between patients with Behçet's disease [CC (P = 0.044), C allele (P = 0.043), A allele (P = 0.043)], and controls. The frequency of the GG genotype at position -137 in patients with Behçet's disease was associated only with a higher rate of ocular manifestations (OR= 1.4, CI= 0.76-2.7, P = 0.031).

CONCLUSION

IL-18 gene polymorphisms were not associated with any susceptibility to aphthous stomatitis, while a positive association was found with patients with Behçet's disease regarding -607 promoter site. Moreover, patients with Behçet's disease carrying the GG genotype at position -137 had a higher risk of developing ocular manifestations.

Vitamin D levels and effects of vitamin D replacement in children with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome

BACKGROUND

The periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome is an autoinflammatory disease characterized by regularly recurrent fever episodes due to seemingly unprovoked inflammation.

OBJECTIVE

To assess serum 25-hydroxyvitamin D [25(OH)D] concentrations in children with PFAPA syndrome and evaluate longitudinally the effect of wintertime vitamin D supplementation on the disease course.

STUDY DESIGN

We have evaluated 25 Italian patients (19 males, 6 females, aged 2.4-5.3 years), fulfilling the Euro-Fever PFAPA criteria. For each patient, we recorded demographic and anthropometric data, clinical manifestations, serum calcium, phosphate, and 25(OH)D. After 400 IU vitamin D supplementation during wintertime, clinical and auxological characteristics, calcium, phosphate, and 25(OH)D levels were re-evaluated. Data were compared with a sex- and age-matched control group.

RESULTS

PFAPA patients showed reduced 25(OH)D levels than controls (p<0.0001). Regarding the effect of seasons on vitamin D, winter 25(OH)D levels were significantly reduced than summer ones (p<0.005). Moreover, these levels were significantly lower than in healthy controls (p<0.005), and correlated with both fever episodes (p<0.005) and C-reactive protein values (p<0.005). After vitamin D supplementation, PFAPA patients showed a significantly decreased number of febrile episodes and modification of their characteristics (mean duration of fever episodes, p<0.05; number of febrile episodes per year p<0.005).

CONCLUSIONS

Deficient and insufficient vitamin D serum levels were found in most children with PFAPA syndrome, and hypovitaminosis D might be a significant risk factor for PFAPA flares. However, vitamin D supplementation seems to significantly reduce the typical PFAPA episodes and their duration, supporting the role of vitamin D as an immune-regulatory factor in this syndrome.

SPAG7 is a candidate gene for the periodic fever, aphthous stomatitis, pharyngitis and adenopathy (PFAPA) syndrome

Periodic fever, aphthous stomatitis, pharyngitis and adenopathy (PFAPA) syndrome is an auto-inflammatory disease for which a genetic basis has been postulated. Nevertheless, in contrast to the other periodic fever syndromes, no candidate genes have yet been identified. By cloning, following long insert size paired-end sequencing, of a de novo chromosomal translocation t(10;17)(q11.2;p13) in a patient with typical PFAPA syndrome lacking mutations in genes associated with other periodic fever syndromes we identified SPAG7 as a candidate gene for PFAPA. SPAG7 protein is expressed in tissues affected by PFAPA and has been functionally linked to antiviral and inflammatory responses. Haploinsufficiency of SPAG7 due to a microdeletion at the translocation breakpoint leading to loss of exons 2-7 from one allele was associated with PFAPA in the index. Sequence analyses of SPAG7 in additional patients with PFAPA point to genetic heterogeneity or alternative mechanisms of SPAG7 deregulation, such as somatic or epigenetic changes.

Development of Kawasaki disease in a patient with PFAPA

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome (PFAPA) is one of the autoinflammatory diseases of unknown etiology characterized by regularly recurrent fever episodes with attacks lasting 3-6 days every 3-8 weeks associated with at least one of the three cardinal clinical signs: aphthous stomatitis, pharyngitis, and cervical adenitis. Kawasaki disease (KD) is an acute, self-limited systemic vasculitis that occurs predominantly in infants and young children. In most KD patients, i.v. immunoglobulin leads to a rapid amelioration of clinical symptoms and significantly decreases the risk of coronary artery aneurysms. Although the etiology of KD is still unknown, it was reported that innate immunity was activated in the patients. Described herein is a patient with PFAPA who developed KD. This is the first report of KD development in a PFAPA patient. The association between KD and PFAPA may represent a genetic predisposition to dysregulated innate immune response.

Treating inflammation by blocking interleukin-1 in humans

IL-1 is a master cytokine of local and systemic inflammation. With the availability of specific IL-1 targeting therapies, a broadening list of diseases has revealed the pathologic role of IL-1-mediated inflammation. Although IL-1, either IL-1α or IL-1β, was administered to patients in order to improve bone marrow function or increase host immune responses to cancer, these patients experienced unacceptable toxicity with fever, anorexia, myalgias, arthralgias, fatigue, gastrointestinal upset and sleep disturbances; frank hypotension occurred. Thus it was not unexpected that specific pharmacological blockade of IL-1 activity in inflammatory diseases would be beneficial. Monotherapy blocking IL-1 activity in a broad spectrum of inflammatory syndromes results in a rapid and sustained reduction in disease severity. In common conditions such as heart failure and gout arthritis, IL-1 blockade can be effective therapy. Three IL-1blockers have been approved: the IL-1 receptor antagonist, anakinra, blocks the IL-1 receptor and therefore reduces the activity of IL-1α and IL-1β. A soluble decoy receptor, rilonacept, and a neutralizing monoclonal anti-interleukin-1β antibody, canakinumab, are also approved. A monoclonal antibody directed against the IL-1 receptor and a neutralizing anti-IL-1α are in clinical trials. By specifically blocking IL-1, we have learned a great deal about the role of this cytokine in inflammation but equally important, reducing IL-1 activity has lifted the burden of disease for many patients.

Elevated levels of CXCL10 in the Periodic Fever, Aphthous stomatitis, Pharyngitis and cervical Adenitis syndrome (PFAPA) during and between febrile episodes; an indication of a persistent activation of the innate immune system

BACKGROUND

The Periodic Fever, Aphthous stomatitis, Pharyngitis and cervical Adenitis syndrome (PFAPA) is the most common periodic fever syndrome in childhood. Clinically, PFAPA may resemble autoinflammatory diseases, but the etiology is not fully understood.

METHODS

We measured inflammatory proteins in plasma and hematologic parameters in children with PFAPA during and between febrile episodes, and in a control group with suspected bacterial pneumonia. In children with PFAPA, a first blood sample was taken within 24 hours of a febrile episode and a second sample between episodes. In children with pneumonia, the first sample was taken shortly after admission and a second sample after full recovery.

RESULTS

A total of 22 children with PFAPA and 14 children with pneumonia were included. In children with PFAPA, levels of interleukin (IL) 6, CXCL10 and CCL4 were significantly increased during febrile episodes. The levels of IL-6 and CXCL10 were higher in children with PFAPA during febrile episodes than in children with pneumonia. The levels of CXCL10 remained higher in children with PFAPA between febrile episodes compared to children with pneumonia after recovery. Children with PFAPA had a relative eosinopenia and lymphocytopenia with reduced numbers of both CD4+ and CD8+ T cells during febrile episodes. This pattern was not observed in the children with pneumonia.

CONCLUSIONS

The results indicate an innate immune response as the initial step in PFAPA, and a subsequent adaptive response with activation and redistribution of T cells. Moreover, an activation of the innate immune system involving CXCL10 may persist between febrile episodes. CXCL10 may be a possibly clinical marker in children with PFAPA.

Prolonged and recurrent fevers in children

Some children referred for prolonged fever are actually not having elevated temperatures; the approach here requires dissection of the history and correction of health misperceptions. Others have well-documented fevers associated with clinical, laboratory, or epidemiologic findings that should point to a specific diagnosis. "Fever-of-Unknown-Origin" (FUO) is the clinical scenario of daily fever for ≥ 14 days that defies explanation after a careful history, physical examination, and basic laboratory tests. The diagnostic approach requires a meticulous fever diary, serial clinical and laboratory evaluations, vigilance for the appearance of new signs and symptoms, and targeted investigations; the pace of the work-up is determined by the severity of the illness. Approximately half of children with FUO will have a self-limited illness and will never have a specific diagnosis made; the other half will ultimately be found to have, in order, infectious, inflammatory, or neoplastic conditions. Irregular, intermittent, recurrent fevers in the well-appearing child are likely to be sequential viral illnesses. Monogenic autoinflammatory diseases should be considered in those who do not fit the picture of recurrent infections and who do not have hallmarks of immune deficiency. Stereotypical febrile illnesses that recur with clockwork periodicity should raise the possibilities of cyclic neutropenia, if the cycle is approximately 21 days, or periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome, the most common periodic fever in childhood.

Gene expression profiles in febrile children with defined viral and bacterial infection

Viral infections are common causes of fever without an apparent source in young children. Despite absence of bacterial infection, many febrile children are treated with antibiotics. Virus and bacteria interact with different pattern recognition receptors in circulating blood leukocytes, triggering specific host transcriptional programs mediating immune response. Therefore, unique transcriptional signatures may be defined that discriminate viral from bacterial causes of fever without an apparent source. Gene expression microarray analyses were conducted on blood samples from 30 febrile children positive for adenovirus, human herpesvirus 6, or enterovirus infection or with acute bacterial infection and 22 afebrile controls. Blood leukocyte transcriptional profiles clearly distinguished virus-positive febrile children from both virus-negative afebrile controls and afebrile children with the same viruses present in the febrile children. Virus-specific gene expression profiles could be defined. The IFN signaling pathway was uniquely activated in febrile children with viral infection, whereas the integrin signaling pathway was uniquely activated in children with bacterial infection. Transcriptional profiles classified febrile children with viral or bacterial infection with better accuracy than white blood cell count in the blood. Similarly accurate classification was shown with data from an independent study using different microarray platforms. Our results support the paradigm of using host response to define the etiology of childhood infections. This approach could be an important supplement to highly sensitive tests that detect the presence of a possible pathogen but do not address its pathogenic role in the patient being evaluated.