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]

The effect of vitamin D supplementation on attacks in PFAPA syndrome patients with low vitamin D levels

BACKGROUND-AIM

To evaluate the effect of vitamin D supplementation on the frequency and duration of attacks in patients of PFAPA syndrome with low vitamin D levels.

METHODS

This retrospective study comprised PFAPA patients with vitamin D deficiency/insufficiency between 2018 and 2023. The frequency and duration of PFAPA attacks before and after vitamin D supplementation were noted.

RESULTS

Seventy-one patients were included. Of the 71 patients, 24 (33.8%) had vitamin D insufficiency, and 47 (66.2%) had vitamin D deficiency. In patients with vitamin D insufficiency, mean attack frequency and mean attack duration before vitamin D supplementation were 4.3 ± 1.9/year and 2.2 ± 1.6 days, respectively, while mean attack frequency and mean attack duration after vitamin D supplementation were 3.5 ± 2.7/year per year and 1.3 ± 0.9 days respectively (p = 0.2, p = 0.2, respectively). In patients with vitamin D deficiency, mean attack frequency and mean attack duration before vitamin D supplementation were 7.4 ± 2.1/year and 2.2 ± 1.6 days, respectively, while mean attack frequency and mean attack duration after vitamin D supplementation were 3.3 ± 2.4/year and 1.3 ± 0.9 days respectively (p < 0.01, p = 0.04, respectively). When the vitamin D level and the frequency of attacks were compared, the cut-off value of vitamin D was found to be 29.7 nmol/L.

CONCLUSIONS

In PFAPA patients with low vitamin D levels, the frequency and duration of PFAPA attacks were reduced with vitamin D supplementation. Especially at vitamin D level cut-off > 29.7 nmol/L, the frequency of attacks reduced significantly.

COVID 19 vaccination as a trigger of acute genital ulcers in an immunocompromised adolescent-case study and literature review

Acute genital ulcers can affect females of all ages. In children, they often appear as an emergency and remain a diagnostic challenge for pediatricians, gynecologists and dermatologists. Prompt diagnosis and identification of disease- related factors help to implement appropriate treatment. Firstly, it is crucial to properly compile the past medical history of the patient. Past infectious, autoimmune, malignant or traumatic conditions, as well as vaccinations may contribute to the occurrence of acute genital ulcers. Moreover, new infectious agents, such as severe acute respiratory syndrome coronavirus 2 and vaccinations against Coronavirus disease of 2019, may play a significant role in the development of atypical clinical symptoms. Here we present a case of a 12-year-old girl with acute genital ulcers. Additional symptoms accompanying the ulcer included: abdominal pain, nausea, vomiting, dysuria, vulvar pain and fever. Blood test showed leukocytosis, especially neutrophilia and monocytosis and increased levels of c-reactive protein and procalcitonin. Serological tests for the most common infections were negative. Moreover, the patient had a history of autoimmune diseases. She had periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome, and IgA vasculitis, also known as Henoch-Schönlein purpura in her past medical history. Additionally, she was vaccinated against SARS-CoV-2 shortly before the lesions appeared.

Case Report: Identification of a CARD8 variant in all three patients with PFAPA syndrome complicated with Kawasaki disease

Background

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA syndrome), and Kawasaki disease (KD) are both considered to be disorders of the innate immune system, and the potential role of inflammasome activation in the immunopathogenesis of both diseases has been previously described.

Case presentation

Herein, we report the clinical courses of three patients who presented a rare combination of PFAPA syndrome and KD. Two patients who presented KD later developed the PFAPA syndrome, of whom one developed recurrent KD 2 years after the initial diagnosis. The third patient developed KD one year after the onset of PFAPA syndrome. The presence of both of these conditions within individual patients, combined with the knowledge that inflammasome activation is involved in both PFAPA syndrome and KD, suggests a shared background of inflammatory dysregulation. To elucidate the mechanism underlying shared inflammatory dysregulation, we investigated the roles of Nod-like receptors (NLRs) and their downstream inflammasome-related genes. All the patients had a frameshift variant in CARD8 (CARD8-FS). A previous study demonstrated a higher frequency of CARD8-FS, whose product loses CARD8 activity and activates the NLRP3 inflammasome, in patients with the PFAPA syndrome. Additionally, the NLRP3 inflammasome is known to be activated in patients with KD. Together, these results suggest that the CARD8-FS variant may also be essential in KD pathogenesis. As such, we analyzed the CARD8 variants among patients with KD. However, we found no difference in the variant frequency between patients with KD and the general Japanese population.

Conclusions

We report the clinical courses of three patients with a rare combination of PFAPA syndrome and KD. All the patients had the CARD8-FS variant. However, we could not find a difference in the variant frequency between patients with KD and the general Japanese population. As the frequency of KD is much higher than that of PFAPA among Japanese patients, and the cause of KD is multifactorial, it is possible that only a small portion of patients with KD harbor CARD8-FS as a causative gene.

Altered serum antibody levels in children with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis

Objectives

This study aimed to extend the literature by analyzing immunoglobulin (Ig) A, IgE, IgG, IgG2, IgG3, and IgM antibody levels in periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) patients.

Patients and methods

This study retrospectively analyzed the antibody test results of 20 pediatric patients (10 males, 10 females; mean age: 2.5±1.5 years; range, 0.5 to 5.4 years) with and without flare who were initially evaluated for a number of underlying diseases due to periodic fever/infectious symptoms but then diagnosed with PFAPA between January 2015 and December 2020. Antibody levels were determined by chemiluminescence microparticle immunoassay. The results were retrospectively compared with a group of healthy children after the PFAPA diagnosis was confirmed.

Results

The chemiluminescence microparticle immunoassay revealed 35%, 65%, 20%, 86.6%, and 55% of PFAPA cases with low serum levels of IgA, IgG, IgG2, IgG3, and IgM respectively, while 56.2% had high IgE levels. Moreover, low serum levels of at least two antibody classes or subclasses were reported in 80% of the PFAPA children. While cases with low IgG serum levels were with the highest incidence rates among the low IgG3 PFAPA patient population, both high IgE and low IgM cases were common in the rest of the patients.

Conclusion

Our results suggest an association between PFAPA and low serum antibody levels, particularly of IgG3. Future studies are needed to confirm our conclusion.

The inhibitory effect of DIF-3 on polyinosinic-polycytidylic acid-induced innate immunity activation in human cerebral microvascular endothelial cells

For the treatment and prevention of autoinflammatory diseases, it is essential to develop the drug, regulating the innate immune system. Although differentiation-inducing factor (DIF) derivatives, extracted from the cellular slime mold, Dictyostelium discoideum, exhibit immunomodulatory effects, their effects on the regulation of innate immunity in brain are unknown. In this study, we used the human cerebral microvascular endothelial cell line, hCMEC/D3, to investigate the effects of DIF derivatives on the generation of C-X-C motif chemokine (CXCL) 10 and interferon (IFN)-β induced by polyinosinic-polycytidylic acid (poly IC). DIF-3 (1-10 μM), but not DIF-1 and DIF-2, dose-dependently inhibited the biosynthesis of not only CXCL10 but also CXCL16 and C-C motif chemokine 2 induced by poly IC. DIF-3 also strongly decreased IFN-β mRNA expression and protein release from the cells induced by poly IC through the prohibition of p65, a subtype of NF-ĸB, not interferon regulatory transcription factor 3 phosphorylation. In the docking simulation study, we confirmed that DIF-3 had a high affinity to p65. These results suggest that DIF-3 regulates the innate immune system by inhibiting TLR3/IFN-β signaling axis through the NF-ĸB phosphorylation inhibition.

Pathogenic NLRP3 mutants form constitutively active inflammasomes resulting in immune-metabolic limitation of IL-1β production

Cryopyrin-associated periodic syndrome (CAPS) is an autoinflammatory condition resulting from monoallelic NLRP3 variants that facilitate IL-1β production. Although these are gain-of-function variants characterized by hypersensitivity to cell priming, patients with CAPS and animal models of the disease may present inflammatory flares without identifiable external triggers. Here we find that CAPS-associated NLRP3 variants are forming constitutively active inflammasome, which induce increased basal cleavage of gasdermin D, IL-18 release and pyroptosis, with a concurrent basal pro-inflammatory gene expression signature, including the induction of nuclear receptors 4 A. The constitutively active NLRP3-inflammasome of CAPS is responsive to the selective NLRP3 inhibitor MCC950 and its activation is regulated by deubiquitination. Despite their preactivated state, the CAPS inflammasomes are responsive to activation of the NF-κB pathway. NLRP3-inflammasomes with CAPS-associated variants affect the immunometabolism of the myeloid compartment, leading to disruptions in lipids and amino acid pathways and impaired glycolysis, limiting IL-1β production. In summary, NLRP3 variants causing CAPS form a constitutively active inflammasome inducing pyroptosis and IL-18 release without cell priming, which enables the host's innate defence against pathogens while also limiting IL-1β-dependent inflammatory episodes through immunometabolism modulation.

HHV-6B detection and host gene expression implicate HHV-6B as pulmonary pathogen after hematopoietic cell transplant

Limited understanding of the immunopathogenesis of human herpesvirus 6B (HHV-6B) has prevented its acceptance as a pulmonary pathogen after hematopoietic cell transplant (HCT). In this prospective multicenter study of patients undergoing bronchoalveolar lavage (BAL) for pneumonia after allogeneic HCT, we test blood and BAL fluid (BALF) for HHV-6B DNA and mRNA transcripts associated with lytic infection and perform RNA-seq on paired blood. Among 116 participants, HHV-6B DNA is detected in 37% of BALs, 49% of which also have HHV-6B mRNA detection. We establish HHV-6B DNA viral load thresholds in BALF that are highly predictive of HHV-6B mRNA detection and associated with increased risk for overall mortality and death from respiratory failure. Participants with HHV-6B DNA in BALF exhibit distinct host gene expression signatures, notable for enriched interferon signaling pathways in participants clinically diagnosed with idiopathic pneumonia. These data implicate HHV-6B as a pulmonary pathogen after allogeneic HCT.

Biological and clinical roles of IL-18 in inflammatory diseases

Several new discoveries have revived interest in the pathogenic potential and possible clinical roles of IL-18. IL-18 is an IL-1 family cytokine with potent ability to induce IFNγ production. However, basic investigations and now clinical observations suggest a more complex picture. Unique aspects of IL-18 biology at the levels of transcription, activation, secretion, neutralization, receptor distribution and signalling help to explain its pleiotropic roles in mucosal and systemic inflammation. Blood biomarker studies reveal a cytokine for which profound elevation, associated with detectable 'free IL-18', defines a group of autoinflammatory diseases in which IL-18 dysregulation can be a primary driving feature, the so-called 'IL-18opathies'. This impressive specificity might accelerate diagnoses and identify patients amenable to therapeutic IL-18 blockade. Pathogenically, human and animal studies identify a preferential activation of CD8+ T cells over other IL-18-responsive lymphocytes. IL-18 agonist treatments that leverage the site of production or subversion of endogenous IL-18 inhibition show promise in augmenting immune responses to cancer. Thus, the unique aspects of IL-18 biology are finally beginning to have clinical impact in precision diagnostics, disease monitoring and targeted treatment of inflammatory and malignant diseases.

The use of ketotifen as long-term anti-inflammatory prophylaxis in children with PFAPA syndrome

Introduction

Periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome (PFAPA) is the most frequent periodic fever syndrome in children. Its pathogenesis is still unknown, but some disease-modifying factors were observed. Several medications were tested for the long-term prophylaxis of inflammatory flares; however, none are standardly used.

Methods

This prospective clinical trial enrolled 142 children (71 girls, 50%) meeting diagnostic criteria for PFAPA syndrome. We analysed selected clinical characteristics and compared laboratory parameters during the flare and attack-free period (at least two weeks after the attack). Moreover, we assessed the possible therapeutic effect of ketotifen on the duration of attack free-periods and clinical picture.

Results

The mean age of patients was 6.81 ± 3.03 years and the mean age of onset of symptoms was 2.31 ± 2.02 years. No significant differences were observed between genders.We recorded a positive family history for PFAPA in 31.69% of patients. Attacks lasted for 2.8 ± 1.2 days, with intervals between attacks of 4 ± 1 weeks. We administered ketotifen in 111 (77.8%) patients, and a positive effect was observed in 86 (77.5%) of patients. We observed prolonged attack-free intervals in patients treated with ketotifen (14.7 ± 8.9 days in comparison with 4.4 ± 1.9 days before the treatment; p<0.001). The used dose of ketotifen was 0.08 ± 0.01 mg/kg/day. Mild side effects were observed in four patients (restlessness, irritability, agitation and constipation).

Discussion

Our data supports the use of ketotifen for long-term prophylaxis in children with PFAPA syndrome with positive effects on the attenuation of disease activity and the prolongation of attack-free periods. Further well-designed studies should confirm the preliminary data.

Adult-onset Periodic Fever, Aphthous Stomatitis, Pharyngitis and Cervical Adenitis Syndrome Responsive to Colchicine

We herein report a rare case of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome that occurred in an 18-year-old man. He visited our hospital with recurrent episodes of a fever, pharyngitis and adenitis without suggestive findings of infection. These episodes resolved within 5 days and recurred quite regularly, with an interval of about 30 days. As the febrile episodes significantly impaired his quality of life, he was treated with colchicine (0.5 mg) as prophylaxis. This completely prevented the episodes during six months of follow-up. Colchicine may therefore be effective in cases of adult-onset PFAPA syndrome.

What is PFAPA syndrome? Genetic clues about the pathogenesis

PURPOSE OF REVIEW

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most common periodic fever syndrome in childhood. Recent studies report genetic susceptibility variants for PFAPA syndrome and the efficacy of tonsillectomy in a broader cohort of patients with recurrent stereotypical fever. In this review, we highlight the findings of these studies and what they may reveal about the pathogenesis of PFAPA.

RECENT FINDINGS

Newly identified genetic susceptibility loci for PFAPA suggest that it is a complex genetic disorder linked to Behçet's disease and recurrent aphthous ulcers. Patients who have PFAPA with some features of Behçet's disease have been reported. Moreover, the efficacy of tonsillectomy has now been described in patients who do not meet the full diagnostic criteria for PFAPA, although the immunologic profile in the tonsils is different from those with PFAPA. Factors that predict response to tonsillectomy are also reported.

SUMMARY

These findings highlight the heterogeneous phenotypes that may be related to PFAPA due to common genetic susceptibility or response to therapy. These relationships raise questions about how to define PFAPA and highlight the importance of understanding of the genetic architecture of PFAPA and related diseases.

A Potential Partnership between Genetics and the Oral Microbiome in Children Displaying Periodic Fever/Aphthosis/Pharyngitis/Adenitis Syndrome

Periodic fever/aphthosis/pharyngitis/adenitis (PFAPA) syndrome was initially described in a small cohort of American children [...].

Diagnostic performance of routine blood parameters in periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome

BACKGROUND

We aimed to investigate the difference between PFAPA and streptococcal tonsillitis (Strep Pharyngitis) by using blood parameters. We want to evaluate the relationship between periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome, and tonsillitis by using NLR.

METHODS

The data of 141 pediatric patients who had applied to our clinic between October 2016 and March 2019 and were diagnosed with PFAPA syndrome and tonsillitis were reviewed from hospital records. The demographic data of the study group were recorded, as were their WBC, neutrophil, and lymphocyte counts, NLR, and MPV values, which are obtained by proportioning these two counts.

RESULTS

CRP and ESR values were significantly higher in the PFAPA group (p = 0.026 and p < 0.001, respectively). No significant difference was determined between the groups in terms of platelet count or lymphocyte count. Receiver operating curve analyses were calculated. The AUC was 0.713 ± 0.04 according to age, and the CRP was 0.607 ± 0.04 (95% confidence interval). Using a cutoff point of >49 months for age, the sensitivity was 0.71 and the specificity was 0.67.

CONCLUSION

With simple laboratory parameters, PFAPA syndrome can be differentiated from a diagnosis of tonsillitis. This may reduce the costs associated with unnecessary antibiotic use. However, these findings still need to be confirmed by other future studies.

Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenitis Syndrome and Syndrome of Unexplained Recurrent Fevers in Children and Adults

Children and adults with autoinflammatory disorders, who often experience recurrent fevers, rashes, cold-induced symptoms, conjunctivitis, lymphadenopathy, recurrent infections, aphthous stomatitis, and abnormal blood cell counts, may present to the allergist/immunologist because the symptoms mimic allergies and disorders of immunity. In recent years, there has been increased recognition of non-monogenic autoinflammatory disorders, including periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome and syndrome of undifferentiated recurrent fevers. For many clinical practitioners, the natural history, diagnostic criteria, differential diagnoses, and preferred therapies remain challenging because of the presumed rarity of patients and the evolving field of autoinflammation. Here, we aim to provide a practical framework for the clinical allergist/immunologist to evaluate and treat this patient population.

Histone demethylase KDM5B licenses macrophage-mediated inflammatory responses by repressing Nfkbia transcription

Macrophages play a critical role in the immune homeostasis and host defense against invading pathogens. However, uncontrolled activation of inflammatory macrophages leads to tissue injury and even fuels autoimmunity. Hence the molecular mechanisms underlying macrophage activation need to be further elucidated. The effects of epigenetic modifications on the function of immune cells draw increasing attention. Here, we demonstrated that lysine-specific demethylase 5B (KDM5B), a classical transcriptional repressor in stem cell development and cancer, was required for the full activation of NF-κB signaling cascade and pro-inflammatory cytokine production in macrophages. KDM5B deficiency or inhibitor treatment protected mice from immunologic injury in both collagen-induced arthritis (CIA) model and endotoxin shock model. Genome-wide analysis of KDM5B-binding peaks identified that KDM5B was selectively recruited to the promoter of Nfkbia, the gene encoding IκBα, in activated macrophages. KDM5B mediated the H3K4me3 modification erasing and decreased chromatin accessibility of Nfkbia gene locus, coordinating the elaborate suppression of IκBα expression and the enhanced NF-κB-mediated macrophage activation. Our finding identifies the indispensable role of KDM5B in macrophage-mediated inflammatory responses and provides a candidate therapeutic target for autoimmune and inflammatory disorders.

Can the effectiveness of tonsillectomy for PFAPA syndrome be predicted based on clinical factors

OBJECTIVES

To evaluate the clinical factors associated with the outcome of tonsillectomy in children with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome, thereby clarifying who would most likely benefit from that surgery.

METHODS

This was a case-control study of 53 PFAPA patients who underwent tonsillectomy and were divided into a complete-resolution group and a postoperative-fever group. Logistic regression analyses were performed using 17 clinical factors as variables to identify factors associated with the surgical outcome. Hierarchical cluster analysis was also performed to evaluate for relationships between phenotypes and surgical outcomes.

RESULTS

Thirty-nine (73.6%) patients had complete resolution after tonsillectomy. In simple logistic regression analysis, the surgical outcome showed significant positive trends with late-onset (odds ratio [OR] 7.1, P = 0.02) and presence of headache (OR 6.5, P = 0.01). In stepwise multiple logistic regression analysis adjusted for age at onset, presence of headache was significantly associated with complete resolution (OR 6.5, P = 0.01). The complete resolution rates for each combination of headache status and age at onset were as follows: presence of headache/age at onset ≥36 months, 100% (14/14); presence of headache/age at onset <36 months, 76.9% (10/13); absence of headache/age at onset ≥36 months, 75.0% (6/8); and absence of headache/age at onset <36 months, 43.8% (7/16). In hierarchical cluster analysis, complete resolution, age at onset, and headache were in the same cluster.

CONCLUSIONS

PFAPA patients with headache and late onset responded well to tonsillectomy. The mechanisms underlying this association may warrant further investigation.

Dermatologic Manifestations of Noninflammasome-Mediated Autoinflammatory Diseases

Autoinflammatory diseases (AIDs) arise from disturbances that alter interactions of immune cells and tissues. They give rise to prominent (auto)inflammation in the absence of aberrant autoantibodies and/or autoreactive T cells. AIDs that are predominantly caused by changes in the inflammasome pathways, such as the NLRP3- or pyrin-associated inflammasome, have gained substantial attention over the last years. However, AIDs resulting primarily from other changes in the defense system of the innate immune system are less well-studied. These noninflammasome-mediated AIDs relate to, for example, disturbance in the TNF or IFN signaling pathways or aberrations in genes affecting the IL-1RA. The spectrum of clinical signs and symptoms of these conditions is vast. Thus, recognizing early cutaneous signs constitutes an important step in differential diagnoses for dermatologists and other physicians. This review provides an overview of the pathogenesis, clinical presentation, and available treatment options highlighting dermatologic aspects of noninflammasome-mediated AIDs.

Efficacy of canakinumab in a patient with adult-onset glucocorticoid-resistant periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome, a polygenic or multifactorial condition, is the most frequent autoinflammatory disease in children. There is increasing evidence that some patients may have a disease onset during adulthood. With regard to PFAPA syndrome treatment, single medium-to-high doses of glucocorticoids during flares constitute the therapy of choice in children and adults, colchicine may be useful in some patients, and tonsillectomy has been reported of utility mainly in paediatric patients. Interleukin-1 (IL-1) blockers have been sporadically used with good response in glucocorticoid-resistant cases. We report a patient with an adult onset of glucocorticoid-resistant PFAPA syndrome and inconsistent response to colchicine and anakinra, who later achieved a complete and sustained response to canakinumab. Although canakinumab seems to be a good therapeutic option in paediatric and adult patients with refractory PFAPA syndrome, the best anti-IL-1 agent and the sequence of administration have to be still determined in well-designed clinical trials.

NLRP3 gene variants and serum NLRP3 levels in periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome

OBJECTIVES

Although most of the autoinfammatory disorders have a confirmed genetic cause, periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome still has an unknown genetic background. However, familial cases of PFAPA syndrome have been reported suggesting a genetic its basis. PFAPA syndrome may also be considered an infammasome disorder as variants in infammasome-associated genes such as CARD8, NLRP3, and MEFV have been reported to contribute to the disease.

METHODS

Polymerase chain reaction (PCR)/Sanger sequencing analysis was performed for the detection of the variations in 71 PFAPA patients and 71 healthy controls. NLRP3 concentrations in serum were measured in 71 PFAPA patients and 71 healthy controls.

RESULTS

No statistically significant differences were observed in the allele or genotype frequencies of the NLRP3 polymorphisms between the controls and patients (P > 0.05). We found no significant differences for NLRP3 serum levels between PFAPA patients and controls (p > 0.05). Mutations in the MEFV gene were detected in 32.5% of our patients (13/40).

CONCLUSIONS

It seems that the synergistic effect of different genes plays a role in the formation of PFAPA syndrome. For this reason, it may be useful to examine the presence of mutations in genes such as NLRP3, MEFV, and CARD8 together while investigating the genetics of PFAPA syndrome. Key points • Familial cases of PFAPA syndrome have been reported suggesting a genetic basis for this syndrome. • Elevated serum or plasma levels of IL-1β, IL-6, and IL-18 have been demonstrated during PFAPA flares in several studies. • It seems that the synergistic effect of different genes plays a role in the formation of PFAPA syndrome.

The Association Between Vitamin D Level and PFAPA Syndrome: A Systematic Review

Periodic Fever, Aphthous Ulcers, Pharyngitis and Adenitis (PFAPA) Syndrome's etiology is not well understood. The objective of this study is to explore the association between vitamin D level and PFAPA syndrome. A systematic review of all publications addressing the association between vitamin D level and PFAPA syndrome prior to May 2019 was conducted. Data were collected from online medical databases namely, PubMed, Ovid Medline, Embase, Cochrane Library, Google Scholar, and Scopus. The review adhered to the PRISMA statement and was performed in 3 main phases; an initial screening review of abstracts was performed, followed by a detailed review of full articles based on inclusion and exclusion criteria, and lastly a final review to extract data from selected articles. 3 prospective review-based and one case report articles were included with a total of 281 patients, 98 of whom were cases of PFAPA, while 183 were controls. Vitamin D levels were deficient in 27% of PFAPA group as compared with the control. Vitamin D supplementation was given as an initial treatment in 25/98 of the patients. Only 1 patient received it as a second treatment. After vitamin D supplementation, a marked reduction of the number of febrile episodes and modification of the mean duration were recognized. There may be an association between Vitamin D deficiency and a higher frequency of PFAPA episodes. Vitamin D supplementation in children with PFAPA may reduce the frequency of episodes and help manage the condition.

Challenges in the diagnosis of periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome in developing countries—A decade of experience from North India

Background

Reports of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome from developing countries are sparse. Recognizing PFAPA is often challenging in these regions due to a higher incidence of infectious illnesses and significant resource constraints. Herein, we present our experience from North India regarding the diagnosis and management of PFAPA syndrome.

Methods

We reviewed cases of non-monogenic periodic fever syndrome diagnosed at our center from January 2011 to December 2021. A total of 17 children who fulfilled the Marshall criteria for PFAPA syndrome were included. Data regarding basic clinical features, treatment/outcome, and performance of the recently proposed Eurofever/PRINTO and Takeuchi criteria were analyzed.

Results

Besides recurrent fever, the triad of oral aphthae, pharyngitis, and adenitis was noted in only 18% of patients. Episodes of exudative pharyngitis/tonsillitis were documented in 24%. These figures were lower than the values reported from developed countries. The Takeuchi and Eurofever/PRINTO criteria were fulfilled in 76% and 71% cases, respectively. In addition to antipyretics and supportive care, intermittent steroid therapy was the main treatment modality used. Additional treatment with colchicine (n = 3) and thalidomide (n = 1) was used successfully in a few patients. Before the diagnosis of PFAPA, all patients had received multiple courses of antimicrobials (without microbiological confirmation). These included multiple courses of antibacterials for fever, pharyngotonsillitis, and/or cervical adenitis in all patients and antivirals for fever and aphthous stomatitis in a patient. Empiric antitubercular therapy had also been administered in two patients.

Conclusions

A significant proportion of patients with PFAPA seem to remain undiagnosed in the Indian subcontinent. Increased awareness and improvement in basic healthcare facilities are crucial in enhancing the recognition of PFAPA, which would eliminate the unprecedented scale of undesirable antimicrobial use in such children.

Epidemiology and clinical features of PFAPA: a retrospective cohort study of 336 patients in western Sweden

BACKGROUND

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome is generally regarded as the most common autoinflammatory disease, but the epidemiology of the disease is largely unknown. The objectives of this study were to estimate the annual incidence and describe the clinical features of PFAPA in a large cohort from western Sweden.

METHODS

The study retrospectively included children < 18 years of age diagnosed with PFAPA between 2006 and 2017 at three hospitals: NU Hospital Group, Skaraborg Hospital and Queen Silvia Children's Hospital. Patients were identified by searching for relevant diagnostic ICD-10 codes in the comprehensive electronic medical records and data were retrieved by reviewing case records. To estimate incidence, patients with symptom onset from January 1, 2006, to December 31, 2016, were included. Population data for the study area during this period were retrieved from Statistics Sweden.

RESULTS

In this study, 336 patients with PFAPA were identified. Of these, 156 (46%) were girls and 180 (54%) were boys. Almost 90% of the children with PFAPA (291 patients) experienced their first symptoms before the age of 5 years and fewer than 3% presented at ages above 10 years. Pharyngitis was the most common symptom during febrile episodes, followed by cervical adenitis and aphthous stomatitis. Fourteen percent of the patients displayed atypical features, of which skin rash was the most common. To calculate incidence, 251 patients with symptom onset during the study period were identified. The mean annual incidence was estimated at 0.86/10,000 for children < 18 years of age and 2.6/10,000 for children < 5 years of age.

CONCLUSIONS

This study adds to the understanding of the epidemiology of PFAPA syndrome by presenting incidence rates based on a large cohort and in different age groups in a population-based setting. It also shows the distribution of age of onset of PFAPA, with a peak in 1-year-olds and waning at older ages. Signs and symptoms of PFAPA syndrome were similar in children with symptom onset before vs. after 5 years of age.

New insights on multigenic autoinflammatory diseases

Autoinflammatory diseases are disorders of the innate immune system, which can be either monogenic due to a specific genetic mutation or complex multigenic due to the involvement of multiple genes. The aim of this review is to explore and summarize the recent advances in pathogenesis, diagnosis, and management of genetically complex autoinflammatory diseases, such as Schnitzler's syndrome; adult-onset Still's disease; synovitis, acne, pustulosis, hyperostosis, osteitis syndrome/chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis; Adamantiades-Behçet's disease; Yao syndrome; and periodic fever with aphthous stomatitis, pharyngitis, and adenitis syndrome. The PubMed database was screened for relevant articles using free text words and specific search strings. The search was limited to English-language articles, reporting the results of studies in humans, published through March 2021. Evidence from literature suggest that these rare multigenic autoinflammatory diseases can present with different clinical features and the diagnosis of these diseases can be challenging due to a combination of nonspecific manifestations that can be seen in a variety of other conditions. Diagnostic delays and disease complications may occur due to low disease awareness and the lack of pathognomonic markers. The pathogeneses of these diseases are complex and in some cases precise pathogenesis is not clearly understood. Conventional treatments are commonly used for the management of these conditions, but biologics have shown promising results. Biologics targeting proinflammatory cytokines including IL-1, IL-6, TNF-α, IL-17A and IL-18 have been shown to ameliorate signs and symptoms of different multigenic autoinflammatory diseases.

PFAPA Syndrome: Clinical, Laboratory and Therapeutic Features in a Single-Centre Cohort

Objective

The aim of this study is to describe a group of Romanian children with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome.

Materials

This consisted of 39 children diagnosed with PFAPA syndrome according to Thomas’ criteria (eight patients with an age at diagnosis <1 year and 31 patients with an age at diagnosis >1 year).

Methods

Retrospective analysis of the patients with PFAPA syndrome was focused on clinical features, laboratory findings and therapeutic methods. Comparison between the two groups divided by age at onset was also investigated.

Results

Median age at onset was 1.58 years, and median age at diagnosis was 2.97 years. The mean interval between episodes was 35.5 days and the mean duration per febrile episode was 4.1 days. The median diagnosis delay was 2.42 years. The patients presented pharyngitis (100%), adenitis (94.8%) and aphthous lesions (66.7%). The frequency of febrile attacks was higher in children with an age at diagnosis under 1 year (p = 0.0287). Younger age was associated with the presence of aphthae. The mean value of C-reactive protein (CRP) was 7.9mg/dl and the mean value of leucocytes was 14,839/mm³. In 95% of patients given oral corticosteroids, remission of symptoms was reported within 24 h. In three patients, tonsillectomy was performed with complete remission of the disease.

Conclusion

We present a cohort of children with PFAPA syndrome, with clinical and laboratory features similar to those described in the literature. Febrile attacks had a higher incidence in children with younger age at the onset of the disease. The patients had a favorable response to corticosteroids.

Periodic Fever in Children: Etiology and Diagnostic Challenges

Periodic fever in children is an autoinflammatory illness with an unknown cause. Symptoms include frequent episodes of fever that are followed by an increase in inflammatory markers. A genetic background for periodic fever of unknown origin has been hypothesized, based on its family clustering and parallels to other autoinflammatory illnesses such as familial Mediterranean fever. Genome analysis has been used in studies to look for related gene variations in periodic fever of unknown origin in the pediatric population. 

Children with periodic fevers might be a diagnostic challenge. After ruling out the most prevalent causes, a wide variety of other possibilities are investigated. Infectious and noninfectious causes of periodic fever in children are discussed in this article.

Inflammasomes (intracellular proteins that activate interleukin (IL)-1b and IL-18) and genetic/hereditary variations are thought to be implicated in the pathogenesis of periodic fever. Evaluation and ruling out possible infective or noninfective causes is vital in the diagnosis of periodic fever in children. Investigations demonstrate that there isn't a single gene linked to it, suggesting that it may have a multifactorial or polygenic origin, with an environmental trigger causing inflammasome activation and fever flares. Treatment is usually symptomatic, with drugs such as colchicine and cimetidine having shown promising results in trials.

We explored the literature on periodic fever in children for its epidemiology, pathophysiology, the role of various genes and how they influence the disease and associated complications, and its various treatment modalities.

The Preferential Use of Anakinra in Various Settings of FMF: A Review Applied to an Updated Treatment-Related Perspective of the Disease

Familial Mediterranean fever (FMF), the most frequent monogenic autoinflammatory disease, is manifested with recurrent and chronic inflammation and amyloid A (AA) amyloidosis, driven by overproduction of interleukin 1 (IL-1) through an activated pyrin inflammasome. Consequently, non-responsiveness to colchicine, the cornerstone of FMF treatment, is nowadays addressed by IL-1- blockers. Each of the two IL-1 blockers currently used in FMF, anakinra and canakinumab, has its own merits for FMF care. Here we focus on anakinra, a recombinant form of the naturally occurring IL-1 receptor antagonist, and explore the literature by using PubMed regarding the utility of anakinra in certain conditions of FMF. Occasionally we enrich published data with our own experience. To facilitate insights to anakinra role, the paper briefs some clinical, genetic, pathogenetic, and management aspects of FMF. The clinical settings of FMF covered in this review include colchicine resistance, AA amyloidosis, renal transplantation, protracted febrile myalgia, on- demand use, leg pain, arthritis, temporary suspension of colchicine, pediatric patients, and pregnancy and lactation. In many of these instances, either because of safety concerns or a necessity for only transient and short-term use, anakinra, due to its short half-life, is the preferred IL-1 blocker.

Therapeutic potential of targeting IL-1 family cytokines in chronic inflammatory skin diseases

The interleukin-1 (IL-1) family of cytokines is a central regulator of a myriad of immunological responses. It comprises several cytokines, including those belonging to the IL-1, IL-36 and IL-18 subfamilies, as well as IL-33. The IL-1 family primarily plays a role in orchestrating innate immune responses but also in adaptive immunity. Increased interest in the IL-1 family occurred following the discovery that dysregulation of IL-1 signalling underlies the pathogenesis of several monogenic auto-inflammatory diseases, characterized by sterile inflammation involving the skin and other organs. This also provided increased understanding of the role of innate immunity and the IL-1 family in polygenic auto-inflammatory skin conditions, such as neutrophilic dermatoses, as well as in some of the most common chronic inflammatory skin diseases, such as psoriasis or hidradenitis suppurativa. Several therapeutic agents have been developed to inhibit the IL-1 family members and their signalling pathways. These have shown therapeutic efficacy in several chronic inflammatory skin disorders. The aim of this review is to thoroughly describe the consequences of pathological dysregulation of IL-1, IL-33, IL-36, IL-18 pathways in dermatological conditions and to provide a forward-looking update on therapeutic strategies targeting signalling by IL-1 family cytokines.

Systemic Autoinflammatory Diseases: A Growing Family of Disorders of Overlapping Immune Dysfunction

Systemic autoinflammatory diseases (SAIDs) are characterized by unprovoked exaggerated inflammation on a continuum from benign recurrent oral ulceration to life-threatening strokes or amyloidosis, with renal failure as a potential sequela. The ability to discriminate these diagnoses rests on the genetic and mechanistic defect of each disorder, considering potential overlapping autoinflammation, autoimmunity, and immune deficiency. A comprehensive and strategic genetic investigation influences management as well as the consequential expected prognoses in these subsets of rare diseases. The ever-expanding therapeutic armamentarium reflects international collaborations, which will hasten genetic discovery and consensus-driven treatment.

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome: A review

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is the most common periodic fever condition in children, with most cases appearing by the age of 5. Although PFAPA is generally a self-limited condition, it can have a major impact on a child's quality of life, as well as that of their family. Recent research has continued to shed light on the genetic and immunologic factors that play a role in the pathogenesis of PFAPA. There also exists significant heterogeneity in treatment strategies, and progress has been made to develop evidence-based management strategies and establish a standard of care. This review will outline current knowledge regarding the pathogenesis of PFAPA, as well as treatment strategies and our clinical experience.

Still's Disease in the Constellation of Hyperinflammatory Syndromes: A Link with Kawasaki Disease?

Still’s disease and Kawasaki disease (KD) today belong to the group of cytokine storm syndromes, a pathophysiological set related to excessive activation of the innate immune response. We present here a personal vision of what can link these two diseases, taking up their concepts at their beginning. By their many clinical and physiopathological similarities, we conclude that they constitute a common spectrum whose fate is modified by subtle differences in terms of adaptive response that could, in part, be driven by genetic factors.

PFAPA (periodic fever, aphthous stomatitis, pharyngitis, and adenitis) syndrome: an overview of genetic background

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is an autoinflammatory disorder with an uncertain origin. PFAPA manifestations occur in the form of regular attacks accompanied by a rise in inflammatory markers. Regarding the family clustering of PFAPA and its similarities with other autoinflammatory disorders such as familial Mediterranean fever, a genetic basis is suggested for the disease. Studies have conducted genome analysis in order to find possible gene variants in PFAPA. Associations with variations in several genes such as MEFV, NLRP, TNFRSF1A, CARD15/NOD2, and MVK have been suggested and analyzed. Inflammasomes, intracellular proteins that are members of innate immunity and activate interleukin-1b (IL-1b) and IL-18, are proposed to be involved in PFAPA pathogenesis. The investigations show that a single gene cannot be found in association with PFAPA, and that it might have a multifactorial or polygenic basis, in which an environmental trigger can provoke inflammasome activation and activate PFAPA flares.

Altered tonsillar toll-like receptor (TLR)-1 and TLR-2 expression levels between periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA), and group A beta-hemolytic streptococcal (GAβHS) recurrent tonsillitis patients

INTRODUCTION

Tonsillar microenvironment is thought to contribute to innate immune dysregulation responsible for the periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) because of beneficial effects of tonsillectomy on treatment of the syndrome. Accordingly previous studies reported altered lymphocyte frequency, cytokine level and microbial composition in PFAPA tonsils. The aim of our study is to monitor expression levels of pro-inflammatory cell surface Toll-like receptors (TLRs) which have important role in induction of inflammation and maintaining tissue haemostasis.

MATERIALS AND METHODS

Seven patients with PFAPA syndrome, and eight patients with group A beta-hemolytic streptococcal (GAβHS) recurrent tonsillitis were included in our study. Tonsillar expression levels of TLR-1, -2, -4, -5, and -6 were monitored by immunohistochemistry (IHC). Expression levels were scored using semi-quantitative analysis method and were statistically analyzed by Two-Way Repeated Measures Analysis of Variance test.

RESULTS

IHC analysis demonstrated expression of all TLRs in tonsillar surface epithelium (SE) and lymphoid interior (LI) except for TLR-6 which was not present in the former. There has not been any statistically significant difference in TLR expression levels between PFAPA and GAβHS tonsils, except for TLR-1 and TLR-2 which were higher on LI and lower on SE of PFAPA tonsils, respectively, than that of the GAβHS samples.

CONCLUSIONS

Altered TLR expression levels may be involved in PFAPA pathogenesis. Future studies with higher patient number, uninflamed tonsils and cellular markers are required to further enlighten the role of TLRs in the development of syndrome.

Undifferentiated recurrent fevers in pediatrics are clinically distinct from PFAPA syndrome but retain an IL-1 signature

Autoinflammatory disorders of the innate immune system present with recurrent episodes of inflammation often beginning in early childhood. While there are now more than 30 genetically-defined hereditary fever disorders, many patients lack a clear diagnosis. Many pediatric patients are often grouped with patients with periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome despite failing to meet diagnostic criteria. Here, we categorize these patients as syndrome of undifferentiated recurrent fever (SURF), and identify the unique features which distinguish them from the PFAPA syndrome. SURF patients were more likely to report gastrointestinal symptoms of nausea, vomiting and abdominal pain, and experienced inconsistent responses to on-demand steroid therapy compared to PFAPA patients. For this previously undefined cohort, an optimal course of therapy remains uncertain, with medical and surgical therapies largely driven by parental preference. A subset of patients with SURF underwent tonsillectomy with complete resolution. Flow cytometric evaluation demonstrates leukocytic populations distinct from PFAPA patients, with reduced CD3+ T cell numbers. SURF patient tonsils were predominantly characterized by an IL-1 signature compared to PFAPA, even during the afebrile period. Peripheral blood signatures were similar between groups suggesting that PFAPA and SURF patient tonsils have localized, persistent inflammation, without clinical symptoms. These data suggest that SURF is a heterogenous syndrome on the autoinflammatory disease spectrum.

Vestibular involvement of PFAPA syndrome

OBJECTIVE

PFAPA syndrome is derived from the initials of the English words of the findings that make up the syndrome ("Periodic Fever", "Aphthous Stomatitis", "Pharyngitis", "Adenitis"). This study aims to evaluate the vestibular system in patients with PFAPA syndrome by the cVEMP test and to give a general review of PFAPA syndrome in light of current literature.

METHODS

In this prospective study, 30 patients aged 4-6 who were diagnosed with PFAPA in a tertiary pediatrics clinic, between January 2016 and February 2020 and 30 children of the same age group who applied to a tertiary otorhinolaryngology clinic for other reasons and proven to have no hearing or vestibular problems were included and in addition to routine physical examination, electromyographic activity of the sternocleidomastoid muscle surface was measured.

RESULTS

We found that the amplitude difference between cVEMP p1-n1 in patients with PFAPA syndrome in both ears decreased compared to the healthy control group.

CONCLUSION

Our study proves there is a vestibular system involvement of PFAPA syndrome. This study is the first in the literature to search the relationship between PFAPA and the vestibular system.

Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis Syndrome: A Rare Etiology of Fever in Adults

We report the case of a 28-year-old male, with a past history of recurrent pharyngitis and tonsillectomy, who presented to the emergency department with fever, pharyngitis, and cervical adenitis. Inflammatory markers were elevated and the patient was initially started on ceftriaxone with remission after four days. However, the symptoms recurred three weeks later and an autoinflammatory disease was suspected. After exclusion of other illnesses, a diagnosis of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome was confirmed. The patient was successfully treated with a single dose of 60 mg of prednisolone at the beginning of the flare.

PFAPA syndrome has been classically diagnosed solely in children but cases in adults are being increasingly recognized. Despite the increasing evidence of the delayed onset of PFAPA syndrome during adulthood, no specific tools are available to detect it and diagnosis is currently based on clinical diagnostic criteria, which have very low specificity and are tailored to pediatric patients. This case report stresses the need to consider this entity seriously despite its rarity, even among the adult population, so as to reduce iatrogenesis, start appropriate therapy in a prompt manner, and improve the quality of life of PFAPA patients.

Off-label use of anti-IL-1 drugs in rheumatic diseases

Interleukin-1 (IL-1) plays a key role in the pathogenesis of different rheumatic diseases. There are now several agents available on the market capable of blocking IL-1. The proven effectiveness and excellent safety of these drugs makes them a possible therapeutic option in the treatment of IL-1 driven diseases, when previous therapies are contraindicated or ineffective. This article discusses the European wide off-label use of these drugs for the treatment of rheumatic diseases.

Galectin-3: a new biomarker for differentiating periodic fever, adenitis, pharyngitis, aphthous stomatitis (PFAPA) syndrome from familial Mediterranean fever?

Differentiating PFAPA (periodic fever, aphthosis, pharyngitis, and adenitis) syndrome from familial Mediterranean fever (FMF) could be challenging in some cases. Galectin-3 is a lectin with regulatory functions in apoptosis and inflammation. We aimed to test whether galectin-3 could be a biomarker for differentiating PFAPA syndrome from FMF. Patients with PFAPA syndrome, FMF, cryopyrin-associated periodic syndrome (CAPS), and streptococcal pharyngitis, and healthy controls were included in this study. Serum galectin-3 levels were measured using enzyme-linked immunosorbent assay. Eighty-seven patients (36 with PFAPA, 39 with FMF, 8 with CAPS, 4 with streptococcal pharyngitis), and 17 healthy controls were included. Blood samples were drawn during attacks from 20 PFAPA and 7 FMF patients and attack-free periods from 22 PFAPA, 35 FMF, and 8 CAPS patients. The median serum galectin-3 level in the PFAPA-attack group (1.025 ng/ml) was significantly lower than the levels in healthy control (2.367 ng/ml), streptococcal pharyngitis (3.021 ng/ml), FMF attack (2.402 ng/ml), and FMF-attack-free groups (2.797 ng/ml) (p = 0.006, 0.03, 0.01, and < 0.001, respectively). PFAPA-attack-free group had lower galectin-3 levels than the FMF-attack-free group (1.794 vs. 2.797 ng/ml, respectively; p = 0.01). Galectin-3 levels did not differ significantly between CAPS and attack-free PFAPA patients (1.439 ng/ml vs. 1.794 ng/ml, respectively; p = 0.63). In our study, for the first time, we defined galectin-3 as a promising biomarker that differs between PFAPA and FMF patients during both disease flares and attack-free periods. Further studies with high number of patients could validate its role as a biomarker.

Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis Syndrome: Relapse and Tonsillar Regrowth After Childhood Tonsillectomy

OBJECTIVES/HYPOTHESIS

Tonsillectomy is an effective treatment for periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome, but the role of adenoidectomy, as well as later tonsillar regrowth, is unclear. To find out if the volume of lymphoid tissue is pivotal to the efficacy, we analyzed the association between the relapse of the symptoms of PFAPA syndrome and regrowth of tonsillar tissue after tonsillectomy or adenotonsillectomy.

STUDY DESIGN

Prospective cohort study of operated PFAPA pateints.

METHODS

We invited all patients that had undergone tonsillectomy or adenotonsillectomy due to PFAPA syndrome at the Oulu University Hospital, Oulu, Finland, between the years 1990 and 2007, at the age of ≤12 years, to a follow-up visit, after an average period of 9.8 years after their diagnoses. Out of the 132 invited, 94 (71%) participated in the follow-up study.

RESULTS

At the follow-up study visit, 5 (5%) of the 94 PFAPA syndrome cases experienced recurrent fevers. The regrowth of palatine tonsillar tissue was seen in four of them (80%) as compared to 19/89 (21%) of symptom-free patients (P = .006). Two of the patients with clear PFAPA relapse at the time of the study visit were reoperated with clear effect on the symptoms. At the time of the study visit, 59/63 (94%) of the patients who had undergone adenotonsillectomy and 30/31 of the patients (97%) who had undergone tonsillectomy earlier were free of fever flares (P = .99).

CONCLUSION

Palatine tonsil regrowth was associated with PFAPA syndrome relapse after tonsillectomy. Reoperation might be a treatment option in these patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E2149-E2152, 2021.

Systemic autoinflammatory disease in adults

Systemic autoinflammatory disorders comprise an expanding group of rare conditions. They are mediated by dysfunction of the innate immune system and share a core of phenotypic manifestations including recurrent attacks of fever, cutaneous signs, chest or abdominal pain, lymphadenopathy, vasculopathy, and musculoskeletal symptoms. Diagnosis is often established in childhood, but a growing number of adult patients are being recognized with systemic autoinflammatory disorders, including adult-onset disease. In this review, we provide a concise update on the pathophysiology, clinical presentation, and diagnostic approach of systemic autoinflammatory disorders with an emphasis on the adult patient population. Despite the recent advances in genetic testing, the diagnosis of autoinflammatory disease in adult patients is often based on a thorough knowledge of the clinical phenotype. Becoming acquainted with the clinical features of these rare disorders may assist in developing a high index of suspicion for autoinflammatory disease in patients presenting with unexplained episodes of fever or inflammation.

Tonsil Mycobiome in PFAPA (Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis) Syndrome: A Case-Control Study

Periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome (PFAPA) is the most common periodic fever syndrome in children with unknown etiology, effectively treated with tonsillectomy. Earlier we have shown that tonsil microbiome is different in patients with PFAPA as compared to that in controls. Recently, fungal microbiome, mycobiome, has been linked to the pathogenesis of inflammatory diseases. We now investigated the role of mycobiome of tonsils in PFAPA. Random forest classification, a machine learning approach, was used for the analysis of mycobiome data. We examined tonsils from 30 children with PFAPA and 22 control children undergoing tonsillectomy for non-infectious reasons. We identified 103 amplicon sequence variants, mainly from two fungal phyla, Ascomycota and Basidiomycota. The mean relative abundance of Candida albicans in the tonsil mycobiome was 11% (95% CI: 19 to 27%) in cases and 3.4 % (95% CI: -0.8% to 8%) in controls, p =0.104. Mycobiome data showed no statistical difference in differentiating between PFAPA cases and controls compared to a random chance classifier (area under the curve (AUC) = 0.47, SD = 0.05, p = 0.809). In conclusion, in this controlled study, tonsillar mycobiome in children with PFAPA syndrome did not differ from that of the controls.

BRLF1 suppresses RNA Pol III-mediated RIG-I inflammasome activation in the early EBV lytic lifecycle

Latent infection with herpesviruses constitutively activates inflammasomes, while lytic replication suppresses their activation through distinct mechanisms. However, how Epstein-Barr virus (EBV) lytic replication inhibits the activation of inflammasomes remains unknown. Here, we reveal that the EBV immediate-early protein BRLF1 inhibits inflammasome activation, and BRLF1 deficiency significantly increases the activation of inflammasomes and pyroptosis during early lytic lifecycle. BRLF1 interacts with RNA polymerase III subunits to suppress immunostimulatory small RNA transcription, RIG-I inflammasome activation, and antiviral responses. Consequently, BRLF1-deficient EBV primary infection induces robust T-cell and NK cell activation and killing through IL-1β and IL-18. A BRLF1-derived peptide that inhibits inflammasome activation is sufficient to suppress T-cell and NK cell responses during BRLF1-deficient EBV primary infection in lymphocytes. These results reveal a novel mechanism involved in the evasion of inflammasome activation and antiviral responses during EBV early lytic infection and provide a promising approach for the manipulation of inflammasomes against infection of oncogenic herpesviruses.

Recurrence of Symptoms Associated with Menstruation in a Patient with a History of Periodic Fevers

BACKGROUND

Periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome is a cyclic autoinflammatory disease generally diagnosed in childhood. There have been studies suggesting a relationship between menstruation and other autoinflammatory syndromes such as familial Mediterranean fever (FMF), but not PFAPA specifically.

CASE

This case describes a patient with a diagnosis of PFAPA who experienced complete resolution with tonsillectomy only to have recurrence of symptoms with onset of menstruation. She experienced symptom control with initiation of oral contraceptives.

SUMMARY AND CONCLUSION

Prior to this case report, there had been no evidence in the literature suggesting a relationship between PFAPA and menstruation despite the observed association in other autoinflammatory syndromes. Onset of menses may be a trigger in PFAPA.

PIK3AP1 and SPON2 Genes Are Differentially Methylated in Patients With Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenitis (PFAPA) Syndrome

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is the most common autoinflammatory disease in children and is often grouped together with hereditary periodic fever syndromes, although its cause and hereditary nature remain unexplained. We investigated whether differential DNA methylation was present in DNA from peripheral blood mononuclear cells (PBMC) in patients with PFAPA vs. healthy controls. A whole-epigenome analysis (MeDIP and MBD) was performed using pooled DNA libraries enriched for methylated genomic regions and identified candidate genes, two of which were further evaluated with methylation-specific restriction enzymes coupled with qPCR (MSRE-qPCR). The analysis showed that the PIK3AP1 and SPON2 gene regions are differentially methylated in patients with PFAPA. MSRE-qPCR proved to be a quick, reliable, and cost-effective method of confirming results from MeDIP and MBD. Our findings indicate that a B-cell adapter protein (PIK3AP1), as the PI3K binding inhibitor of inflammation, and spondin-2 (SPON2), as a pattern recognition molecule and integrin ligand, could play a role in the etiology of PFAPA. Their role and the impact of changed DNA methylation in PFAPA etiology and autoinflammation need further investigation.

Oral Mucosal Injury Caused by Targeted Cancer Therapies

Targeted cancer therapies have fundamentally transformed the treatment of many types of cancers over the past decade, including breast, colorectal, lung, and pancreatic cancers, as well as lymphoma, leukemia, and multiple myeloma. The unique mechanisms of action of these agents have resulted in many patients experiencing enhanced tumor response together with a reduced adverse event profile as well. Toxicities do continue to occur, however, and in selected cases can be clinically challenging to manage. Of particular importance in the context of this monograph is that the pathobiology for oral mucosal lesions caused by targeted cancer therapies has only been preliminarily investigated. There is distinct need for novel basic, translational, and clinical research strategies to enhance design of preventive and therapeutic approaches for patients at risk for development of these lesions. The research modeling can be conceptually enhanced by extrapolating "lessons learned" from selected oral mucosal conditions in patients without cancer as well. This approach may permit determination of the extent to which pathobiology and clinical management are either similar to or uniquely distinct from oral mucosal lesions caused by targeted cancer therapies. Modeling associated with oral mucosal disease in non-oncology patients is thus presented in this context as well. This article addresses this emerging paradigm, with emphasis on current mechanistic modeling and clinical treatment. This approach is in turn designed to foster delineation of new research strategies, with the goal of enhancing cancer patient treatment in the future.

Common genetic susceptibility loci link PFAPA syndrome, Behçet's disease, and recurrent aphthous stomatitis

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most common periodic fever syndrome in children. The disease appears to cluster in families, but the pathogenesis is unknown. We queried two European-American cohorts and one Turkish cohort (total n = 231) of individuals with PFAPA for common variants previously associated with two other oropharyngeal ulcerative disorders, Behçet's disease and recurrent aphthous stomatitis. In a metaanalysis, we found that a variant upstream of IL12A (rs17753641) is strongly associated with PFAPA (OR 2.13, P = 6 × 10-9). We demonstrated that monocytes from individuals who are heterozygous or homozygous for this risk allele produce significantly higher levels of IL-12p70 upon IFN-γ and LPS stimulation than those from individuals without the risk allele. We also found that variants near STAT4, IL10, and CCR1-CCR3 were significant susceptibility loci for PFAPA, suggesting that the pathogenesis of PFAPA involves abnormal antigen-presenting cell function and T cell activity and polarization, thereby implicating both innate and adaptive immune responses at the oropharyngeal mucosa. Our results illustrate genetic similarities among recurrent aphthous stomatitis, PFAPA, and Behçet's disease, placing these disorders on a common spectrum, with recurrent aphthous stomatitis on the mild end, Behçet's disease on the severe end, and PFAPA intermediate. We propose naming these disorders Behçet's spectrum disorders to highlight their relationship. HLA alleles may be factors that influence phenotypes along this spectrum as we found new class I and II HLA associations for PFAPA distinct from Behçet's disease and recurrent aphthous stomatitis.

Current Therapeutic Options for the Main Monogenic Autoinflammatory Diseases and PFAPA Syndrome: Evidence-Based Approach and Proposal of a Practical Guide

Monogenic autoinflammatory diseases are rare conditions caused by genetic abnormalities affecting the innate immunity. Previous therapeutic strategies had been mainly based on results from retrospective studies and physicians' experience. However, during the last years, the significant improvement in their genetic and pathogenic knowledge has been accompanied by a remarkable progress in their management. The relatively recent identification of the inflammasome as the crucial pathogenic mechanism causing an aberrant production of interleukin 1β (IL-1β) in the most frequent monogenic autoinflammatory diseases led to the introduction of anti-IL-1 agents and other biologic drugs as part of the previously limited therapeutic armamentarium available. Advances in the treatment of autoinflammatory diseases have been favored by the use of new biologic agents and the performance of a notable number of randomized clinical trials exploring the efficacy and safety of these agents. Clinical trials have contributed to increase the level of evidence and provided more robust therapeutic recommendations. This review analyzes the treatment of the most frequent monogenic autoinflammatory diseases, namely, familial Mediterranean fever, tumor necrosis factor receptor-associated periodic fever syndrome, hyperimmunoglobulin D syndrome/mevalonate kinase deficiency, and cryopyrin-associated periodic syndromes, together with periodic fever with aphthous stomatitis, pharyngitis, and cervical adenitis syndrome, which is the most common polygenic autoinflammatory disease in children, also occurring in adult patients. Finally, based on the available expert consensus recommendations and the highest level of evidence of the published studies, a practical evidence-based guideline for the treatment of these autoinflammatory diseases is proposed.

Why and How Should We Treat Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis (PFAPA) Syndrome?

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is characterized by recurrent fever flares accompanied by symptoms and signs forming the disease acronym and alternating with asymptomatic periods. Despite the disease having a generally favorable outcome, with spontaneous remission after a few years, it does have a major impact on the quality of life of the child and his or her relatives. Beside symptomatic medications during fever flares, the most used treatment consists of a single dose of corticosteroids at flare onset to interrupt the attack; fever resolves usually within a few hours, but often with a shorter interval between the attacks. For these patients, colchicine has been shown to decrease the frequency of the flares. Other medications were also reported in case series of patients with PFAPA syndrome. These include the interleukin-1 blocker anakinra to treat flares, cimetidine (which showed no convincing effect), and other drugs with anecdotal use. The pediatrician faces a difficult question: should they wait for spontaneous disease resolution and only treat the flares medically, or should they propose tonsillectomy that may induce remission? Due to the lack of strong evidence, the answer will vary on an individual basis, depending on the impact on the patient's quality of life. The choice of the best therapeutic strategy will be based on the response to the flare-based therapy and on disease severity (quality of life, school performances); long-term data on the remission rate under the different therapeutic strategies are currently missing. More randomized controlled studies are needed to help the treating physician to choose the best therapy, as well as real-life long-term data to evaluate the long-term outcome of children with PFAPA syndrome.