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]

Incidence, clinical characteristics and outcome in Norwegian children with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome; a population-based study

AIM

To describe the incidence, epidemiology, clinical presentation and clinical outcome of children with the syndrome of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) in a population-based study.

METHODS

In a prospective population-based study, all children in South Rogaland, Norway, diagnosed with PFAPA during 2004-2010 were evaluated clinically, and parents were interviewed systematically. A follow-up interview was performed for all patients.

RESULTS

A total of 46 children (32 boys; p = 0.011) were diagnosed with PFAPA. We calculated an incidence of 2.3 per 10 000 children up to 5 years of age. The median age of onset was 11.0 months (quartiles: 5.0, 14.8). Nearly 37 children were followed until resolution. In 17 of these, a tonsillectomy was performed with prompt resolution of PFAPA in all. The median age of spontaneous resolution was 60.2 months (range 24-120) and in children with tonsillectomy 50.9 months (range 15-128).

CONCLUSION

The incidence of PFAPA was 2.3 per 10 000 children up to 5 years of age. In the majority of cases, onset of symptoms may be during the first year of life.

Statin-induced T-lymphocyte modulation and neuroprotection following experimental subarachnoid hemorrhage

INTRODUCTION

Statins influence immune system activities through mechanisms independent of their lipid-lowering properties. T cells can be subdivided based on cytokine secretion patterns into two subsets: T-helper cells type 1 (Th1) and type 2 (Th2). Independent laboratory studies have shown statins to be potent inducers of a Th2 switch in immune cell response and be neuroprotective in several models of central nervous system (CNS) disease. This study was the first to evaluate the immune modulating effects of statins in subarachnoid hemorrhage (SAH).

METHODS

Simvastatin was administered to rats intraperitoneally in two dosages (1 and 20 mg/kg) 30 min after the induction of SAH using endovascular perforation. Neurological scores were assessed 24 h later. Animals were then sacrificed, and samples of cortex and brain stem were tested for expression of the T-regulatory cell cytokine transforming growth factor (TGF) β1, as well as interleukin (IL) 1β, a proinflammatory cytokine associated with Th1 immune responses. The presence of TGF-β1 secreting T cells was evaluated with the use of brain slices.

RESULTS

SAH significantly impaired neurological function in all SAH groups (treated and untreated) versus sham. Animals treated with high-dose simvastatin had less neurological impairment than both untreated and low-dose groups. Cortical and brain-stem levels of TGF-β1 were significantly elevated following SAH in the high-dose group. IL-1β was significantly elevated following the induction of SAH but was inhibited by high-dose simvastatin. Double-labeled fluorescent immunohistochemical data demonstrated the presence of lymphocytes in the subarachnoid and perivascular spaces following SAH. Expression of TGF-β1 by lymphocytes was markedly increased following treatment with high-dose simvastatin.

CONCLUSION

The present study elucidated the potential role of a Th2 immune switch in statin provided neuroprotection following SAH.

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome and IgA nephropathy

BACKGROUND

A syndrome of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA), as well as immunoglobulin A nephropathy (IgAN), may be caused by autoimmune reactivity nephropathy.

CASE-DIAGNOSIS/TREATMENT

A 10-year-old boy presented with periodic fever, exudative tonsillitis, oral aphthous ulcer, and cervical lymph node inflammation. These conditions had occurred at intervals of about 2-6 weeks since the age of 3 years. Microscopic hematuria, first detected at age 8 years, worsened during episodes of PFAPA-related fever; since 10 years of age, the hematuria was accompanied by sustained proteinuria. Examination of a kidney biopsy specimen led to a diagnosis of IgAN. In the kidney specimen, fractalkine immunoreactivity and heavy macrophage infiltration were prominent. Multi-drug cocktail therapy improved the urinalysis findings, and subsequent tonsillectomy succeeded in controlling recurrences of PFAPA and IgAN. In a post-treatment renal biopsy specimen, mesangial proliferation was decreased, and fractalkine immunoreactivity was absent.

CONCLUSION

Immunologic reactions against certain antigens in local mucosa, including tonsils, may be impaired in PFAPA and IgAN, as evidenced by the suppression of both diseases in our patient by tonsillectomy. Accordingly, the concurrence of PFAPA and IgAN in our patient appeared to be a consequence of shared autoimmune mechanisms and systemic and local increases in cytokine concentrations, rather than coincidence.

Periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis syndrome is linked to dysregulated monocyte IL-1β production

BACKGROUND

The exact pathogenesis of the pediatric disorder periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis (PFAPA) syndrome is unknown.

OBJECTIVES

We hypothesized that PFAPA might be due to dysregulated monocyte IL-1β production linked to genetic variants in proinflammatory genes.

METHODS

Fifteen patients with PFAPA syndrome were studied during and outside a febrile episode. Hematologic profile, inflammatory markers, and cytokine levels were measured in the blood. The capacity of LPS-stimulated PBMCs and monocytes to secrete IL-1β was assessed by using ELISA, and active IL-1β secretion was visualized by means of Western blotting. Real-time quantitative PCR was performed to assess cytokine gene expression. DNA was screened for variants of the MEFV, TNFRSF1A, MVK, and NLRP3 genes in a total of 57 patients with PFAPA syndrome.

RESULTS

During a febrile attack, patients with PFAPA syndrome revealed significantly increased neutrophil counts, erythrocyte sedimentation rates, and C-reactive protein, serum amyloid A, myeloid-related protein 8/14, and S100A12 levels compared with those seen outside attacks. Stimulated PBMCs secreted significantly more IL-1β during an attack (during a febrile episode, 575 ± 88 pg/mL; outside a febrile episode, 235 ± 56 pg/mL; P < .001), and this was in the mature active p17 form. IL-1β secretion was inhibited by ZYVAD, a caspase inhibitor. Similar results were found for stimulated monocytes (during a febrile episode, 743 ± 183 pg/mL; outside a febrile episode, 227 ± 92 pg/mL; P < .05). Genotyping identified variants in 15 of 57 patients, with 12 NLRP3 variants, 1 TNFRSF1A variant, 4 MEFV variants, and 1 MVK variant.

CONCLUSION

Our data strongly suggest that IL-1β monocyte production is dysregulated in patients with PFAPA syndrome. Approximately 20% of them were found to have NLRP3 variants, suggesting that inflammasome-related genes might be involved in this autoinflammatory syndrome.

Treating inflammation by blocking interleukin-1 in a broad spectrum of diseases

Interleukin-1 (IL-1) is a highly active pro-inflammatory cytokine that lowers pain thresholds and damages tissues. Monotherapy blocking IL-1 activity in autoinflammatory syndromes results in a rapid and sustained reduction in disease severity, including reversal of inflammation-mediated loss of sight, hearing and organ function. This approach can therefore be effective in treating common conditions such as post-infarction heart failure, and trials targeting a broad spectrum of new indications are underway. So far, three IL-1-targeted agents have been approved: the IL-1 receptor antagonist anakinra, the soluble decoy receptor rilonacept and the neutralizing monoclonal anti-IL-1β antibody canakinumab. In addition, a monoclonal antibody directed against the IL-1 receptor and a neutralizing anti-IL-1α antibody are in clinical trials.

C-reactive protein and procalcitonin during febril attacks in PFAPA syndrome

OBJECTIVES

To assess the levels of procalcitonin (PCT) and C-reactive protein (CRP) in children diagnosed with PFAPA (periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis) during their febrile attacks.

METHODS

23 patients with diagnosis of PFAPA included into the study prospectively during a three years period. In these patients, CRP and PCT values were recorded during 78 febrile episodes. Furthermore, 20 patients with diagnosis of pneumonia were chosen as a control group and their CRP and PCT values were measured. Normal reference values for CRP and PCT were 0-10 mg/L and 0-0.5 ng/mL, respectively.

RESULTS

Mean CRP and PCT values of patients with PFAPA were 94.8±71.6 mg/L and 0.29±0.14 ng/mL, respectively. In control group, mean CRP value was 153.2±26 mg/L and PCT was 1.59±0.53 ng/mL. CRP and PCT were high in control group. CRP was detected high and PCT was normal in PFAPA. Compared to control group, in PFAPA group, CRP values were not significantly (p>0.05) and PCT values were significantly lower (p<0.001).

CONCLUSION

During febrile episodes in the patients with diagnosis of PFAPA, CRP values were substantially elevated, whereas PCT values were within normal levels. Concomitant assessment of CRP and PCT in addition to clinical diagnostic criteria may be of help in making diagnosis and distinguishing febrile attacks from infections. However, studies in larger groups are required.

Pediatric infectious disease: unusual head and neck infections

Infections in children in the head and neck regions are common, leading to frequent use and overuse of antibiotics. This review includes common as well as diverse and unusual infectious diseases, such as PFAPA (Periodic Fever Aphthous stomatitis, Pharyngitis, Adenitis) syndrome, Lemierre Syndrome, Arcanobacterium infection, and tuberculous and nontuberculous adenitis, which occur in infants, children, and adolescents. In addition, the first pediatric vaccines available with the potential to prevent oropharyngeal cancers are reviewed.

Autoinflammatory syndromes

There has been an expansion of the autoinflammatory syndromes due to the discovery of new diseases related to mutations in genes regulating the innate immune system and the knowledge gained from these diseases as applied to more common nongenetic inflammatory conditions. Autoinflammatory syndromes are characterized by unprovoked (or triggered by minor events) recurrent episodes of systemic inflammation involving various body systems, which are often accompanied by fever. Inflammation is mediated by polymorphonuclear and macrophage cells through cytokines, particularly interleukin-1. This article reviews the clinical approach to patients with suspected autoinflammatory syndromes, several of the main and new (mostly genetics) syndromes, advances in treatment, and prognosis.

Immunology in clinic review series; focus on autoinflammatory diseases: update on monogenic autoinflammatory diseases: the role of interleukin (IL)-1 and an emerging role for cytokines beyond IL-1

OTHER THEMES PUBLISHED IN THIS IMMUNOLOGY IN THE CLINIC REVIEW SERIES Allergy, Host Responses, Cancer, Type 1 diabetes and viruses, Metabolic diseases.

SUMMARY

The disease-based discovery of the molecular basis for autoinflammatory diseases has led not only to a rapidly growing number of clinically and genetically identifiable disorders, but has unmantled key inflammatory pathways such as the potent role of the alarm cytokine interleukin (IL)-1 in human disease. Following its initial failures in the treatment of sepsis and the moderate success in the treatment of rheumatoid arthritis, IL-1 blocking therapies had a renaissance in the treatment of a number of autoinflammatory conditions, and IL-1 blocking therapies have been Food and Drug Administration (FDA)-approved for the treatment of the autoinflammatory conditions: cryopyrin-associated periodic syndromes (CAPS). CAPS and deficiency of the IL-1 receptor antagonist (DIRA), both genetic conditions with molecular defects in the IL-1 pathway, have provided a pathogenic rationale to IL-1 blocking therapies, and the impressive clinical results confirmed the pivotal role of IL-1 in human disease. Furthermore, IL-1 blocking strategies have shown clinical benefit in a number of other genetically defined autoinflammatory conditions, and diseases with clinical similarities to the monogenic disorders and not yet identified genetic causes. The discovery that IL-1 is not only triggered by infectious danger signals but also by danger signals released from metabolically 'stressed' or even dying cells has extended the concept of autoinflammation to disorders such as gout, and those that were previously not considered inflammatory, such as type 2 diabetes, coronary artery disease, obesity and some degenerative diseases, and provided the conceptual framework to target IL-1 in these diseases. Despite the tremendous success of IL-1 blocking therapy, the use of these agents in a wider spectrum of autoinflammatory conditions has uncovered disease subsets that are not responsive to IL-1 blockade, including the recently discovered proteasome-associated autoinflammatory syndromes such as chronic atypical neutrophilic dermatitis with lipodystrophy and elevated temperatures (CANDLE), Japanese autoinflammatory syndrome with lipodystrophy (JASL), Nakajo-Nishimura syndrome (NNS) and joint contractures, muscle atrophy, panniculitis induced lipodystrophy (JMP), and urge the continued quest to characterize additional dysregulated innate immune pathways that cause autoinflammatory conditions.

[Periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome]

Periodic fever, aphthous stomatitis, pharyngitis and adenitis (PFAPA) syndrome is a non-hereditary autoinflammatory disease, characterized by relatively regular recurrence of febrile episodes of 3-6 days duration, accompanied by aphthous stomatitis, pharyngitis/tonsillitis, and/or cervical adenititis. It is considered to be the most common periodic fever syndrome in Japan. Although no responsible gene is identified, some genetic factors may confer the predisposition toward this disorder. Important differential diagnosis includes hereditary periodic syndromes and cyclic neutropenia. Although its etiology is still to be elucidated, a recent study suggested an environmentally triggered activation of complement and IL-1β/IL-18 during PFAPA syndrome flares, with induction of Th1-chemokines and subsequent retention of activated T cells in peripheral tissues. This study also demonstrated the possibility that IP-10/CXCL10 might serve as a potential biomarker to differentiate PFAPA syndrome from other periodic fever syndromes. Therapeutic strategy for PFAPA syndrome has not been well established. Recent advances in the understating of etiology and pathophysiology might lead to re-evaluation of recent therapeutic options and/or development of new treatment.

The fresco of autoinflammatory diseases from the pediatric perspective

Autoinflammatory diseases are genetic or acquired clinical entities globally caused by the aberrant release of the proinflammatory cytokine interleukin-1 and mostly characterized by recurrent spontaneous inflammatory events which do not produce antigen-specific T cells or autoantibodies. Within the past decade, the list of autoinflammatory diseases has included cryopyrin-associated periodic syndromes, familial Mediterranean fever, mevalonate kinase deficiency, tumor necrosis factor receptor-associated periodic syndrome, hereditary pyogenic disorders, pediatric granulomatous autoinflammatory diseases, idiopathic febrile syndromes, complement dysregulation syndromes and Behçet's disease. Most of these conditions interact with the inflammasomes, intracellular molecular complexes coordinating the phylogenetically ancient response of the innate immune system. The pathogenetic mechanisms of these diseases have shown the evidence of disrupted interleukin-1 signaling for most of them and allowed to locate interleukin-1 as an attractive therapeutic target. The whole fresco of autoinflammatory diseases in pediatrics will be discussed in this review with the aim of establishing both diagnostic clues and treatments for each condition.

A clinical perspective of IL-1β as the gatekeeper of inflammation

An expanding spectrum of acute and chronic non-infectious inflammatory diseases is uniquely responsive to IL-1β neutralization. IL-1β-mediated diseases are often called "auto-inflammatory" and the dominant finding is the release of the active form of IL-1β driven by endogenous molecules acting on the monocyte/macrophage. IL-1β activity is tightly controlled and requires the conversion of the primary transcript, the inactive IL-1β precursor, to the active cytokine by limited proteolysis. Limited proteolysis can take place extracellularly by serine proteases, released in particular by infiltrating neutrophils or intracellularly by the cysteine protease caspase-1. Therefore, blocking IL-1β resolves inflammation regardless of how the cytokine is released from the cell or how the precursor is cleaved. Endogenous stimulants such as oxidized fatty acids and lipoproteins, high glucose concentrations, uric acid crystals, activated complement, contents of necrotic cells, and cytokines, particularly IL-1 itself, induce the synthesis of the inactive IL-1β precursor, which awaits processing to the active form. Although bursts of IL-1β precipitate acute attacks of systemic or local inflammation, IL-1β also contributes to several chronic diseases. For example, ischemic injury, such as myocardial infarction or stroke, causes acute and extensive damage, and slowly progressive inflammatory processes take place in atherosclerosis, type 2 diabetes, osteoarthritis and smoldering myeloma. Evidence for the involvement of IL-1β and the clinical results of reducing IL-1β activity in this broad spectrum of inflammatory diseases are the focus of this review.