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

The first proteomics analysis of tonsils in patients with periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome (PFAPA)

BACKGROUND

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is a recurrent fever syndrome. The exact etiopathogenesis of PFAPA syndrome remains unknown. Biological fluids or tissues may provide disease-specific biomarkers that may help clinicians to find new pathogenic pathways.

METHODS

Tonsil tissues of seven patients with PFAPA were collected during the tonsillectomy. Seven patients who underwent tonsillectomy for reasons other than chronic tonsillitis were enrolled as a control group. The nHPLC LC-MS/MS system was used for protein identification and label-free quantification. Bioinformatics analysis was carried out using the UniProt accession numbers of the identified proteins.

RESULTS

Proteomics analysis revealed to identity of proteins of which at least 23 were up and 57 were downregulated. Bioinformatics analysis of differentially regulated proteins by STRING indicated that protein folding and clearance machinery were interrupted in PFAPA patients compared to the controls. The affected pathways underlined the importance of the mitochondrial electron transport chain and ATP biosynthesis process.

CONCLUSION

Although it is not clear that changes in tonsil protein expression whether directly related to pathogenesis or simply result of chronic inflammation, the identification of tonsil biomarkers for PFAPA may provide clinicians an opportunity to understand disease pathogenesis or develop new molecular targets for treatments.

IMPACT

Proteomics analyses of tonsils revealed the identity of 80 proteins of which at least 23 were up and 57 were downregulated. Bioinformatics analysis underlined the importance of mitochondrial ETC and regulation of ATP biosynthetic process. This is the first study evaluating the proteomics of the tonsils of PFAPA patients. The identification of tonsil biomarkers for PFAPA may provide clinicians an opportunity to understand disease pathogenesis or develop new molecular targets for treatments.

Perioperative care of the patient with a periodic fever syndrome

Periodic fever syndromes are autoinflammatory disorders associated with recurrent fevers unrelated to infection. Little is known about the perioperative management of patients with these syndromes, and existing literature consists primarily of case reports and occasional case series. This narrative review discusses background information and diagnostic criteria for the three most common periodic fever syndromes: periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA), familial Mediterranean fever (FMF), and TNF receptor-associated periodic syndrome (TRAPS), and describes perioperative considerations for anesthesia providers when caring for the patient with a periodic fever syndrome. We include a systems-based framework in which to organize these considerations.

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.

Tonsillotomy for Periodic Fever Syndrome: A Randomized and Controlled Trial

OBJECTIVE

Tonsillectomy is an effective treatment for periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome. Tonsillotomy has a milder operative risk profile and postoperative morbidity in children than tonsillectomy. We aimed to compare the efficacy of tonsillotomy to observation-only in children with PFAPA syndrome at a 3-month follow-up.

METHODS

This was a randomized multicenter trial with sequential design. Participants were randomized into a tonsillotomy group and a control group that was only observed. The trial started in 1/2017 and was accomplished in 12/2021 with 16 patients (10 boys, six girls, the mean age 4.2 years). The symptoms were monitored with daily symptom diaries.

RESULTS

After the 3-month follow-up, 7/8 patients (87.5%) in the tonsillotomy group and 2/8 (25%) patients in the control group were free from PFAPA symptoms (95% CI 13% to 87%; p = 0.0021). The mean number of days with fever was 2.6 (SD 3.7) in the tonsillotomy group and 8.0 (SD 6.5) days in the control group (n = 8) (p = 0.06). Mean number of fever days compatible with PFAPA syndrome was 0.8 (SD 1.4) in the tonsillotomy group and 6.5 (SD 6.0) in the control group (95%CI -10% to -1%; p = 0.007). Rescue tonsillectomy was needed for all patients in the control group and none of the patients in the tonsillotomy group.

CONCLUSIONS

Tonsillotomy might be an effective treatment option for children with PFAPA syndrome. Further studies are needed to clarify the long-term efficacy of tonsillotomy for treating PFAPA.

LEVEL OF EVIDENCE

2 Laryngoscope, 134:968-972, 2024.

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.

Exploring the immunological basis of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome: immunohistochemical staining features of palatine tonsils

OBJECTIVES

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is the most common periodic fever syndrome during early childhood period with regular febrile attacks of sterile upper airway inflammation. The cessation of attacks following tonsillectomy points to fundamental role of tonsil tissue on etiopathogenesis of disease, which is not clarified satisfactorily. The aim of this study is to explore the immunological basis of PFAPA by evaluating the cellular properties of tonsils, and microbial exposition such as Helicobacter pylori on tonsillectomy materials.

METHODS

The paraffinized tonsil samples of 26 PFAPA and 29 control patients with obstructive upper airway disorder were compared in terms of immunohistochemical staining features including CD4, CD8, CD123, CD1a, CD20, and H. pylori.

RESULTS

The median number of CD8+ cells was 1485 (1218-1287) in PFAPA while it was 1003 (852-1261.5) in control group and the difference was statistically significant (p=0.001). Similarly, CD4+ cell counts were statistically higher in PFAPA group than control (833.5 vs 622). The ratio of CD4/CD8 did not differ between two groups; also, there was no statistically difference in terms of the other immunohistochemical staining results, such as CD20, CD1a, CD123 and H. pylori.

CONCLUSION

This is the largest number of pediatric tonsillar tissue study of PFAPA patients in current literature and we emphasized the triggering effects of CD8+ and CD4+ T-cells on PFAPA tonsils.

KEY POINTS

• The cessation of attacks following tonsillectomy points to fundamental role of tonsil tissue on etiopathogenesis of disease, which is not clarified satisfactorily. • In current study, 92.3% of our patients did not experience any attacks following operation similarly with literature. • We observed the increased number of CD4+ and CD8+ T cell counts on PFAPA tonsils compared to control group and emphasized the active role of both CD4+ and CD8+ cells localized on PFAPA tonsils in immune dysregulation. • Some other cell types evaluated in this study such as CD19+ (B cells), CD1a (dendritic cells), and CD123 (IL-3 receptors, for pluripotent stem cells) and H. pylori did not differ in PFAPA patients compared to the control group.

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.

The role of inflammatory mediators in the pathogenesis of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome

INTRODUCTION

As a recurrent disease, periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is characterized by episodes of febrile attacks and is often prominent in children under five years of age. However, the etiology of this condition has not been fully understood yet.

MATERIALS AND METHODS

The search in the extensive literature of peer-reviewed articles published from the inception to December 2021 was conducted to identify the relevant studies, using the electronic databases of MEDLINE/PubMed, Embase, Scopus, the Cochrane Library, and the Web of Science.

RESULTS

The analysis of complex relationships indicates that inflammatory factors, such as various cytokines and acute-phase proteins (APPs), play leading roles in the pathogenesis of this disease. Accordingly, this article summarizes the current state of knowledge to explain the mechanisms involved in inflammatory responses among patients with PFAPA syndrome and investigate its role in the pathogenesis of this disease. Moreover, the possibilities for further implementation of new therapeutic strategies are pointed out.

CONCLUSION

It is concluded that some pathophysiological processes are associated with immune dysregulation, which itself may be secondary to environmental factors, genetic background, and underlying diseases, including latent infections that multiply inflammatory mediators. elevated inflammatory markers similarly play a significant part in the clinical outcomes of this condition, whose pyrogenic nature is the reason for the development of episodes of febrile attacks in the population of patients suffering from PFAPA syndrome.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome (PFAPA) or recurrent urinary tract infections: a case report

BACKGROUND

Fever is the most frequent reason for medical consultation in children, and makes up 15-25% of all consultations in primary care and emergency departments. In here we report a case of a 13 year-old girl who referred with an unusual presentation of fever and was misdiagnosed with recurrent urinary tract infection for 8 years.

CASE PRESENTATION

This is a Clinical Reasoning Cycle case study. A 13 year-old girl was referred with a chief complaint of recurrent fevers from 8 years. During her first febrile episode, she had a 5-day high-grade fever associated with loss of appetite. Her physical examination at that time was unremarkable. Blood tests showed leukocytosis with a shift to the left and urine examination was in favor of pyuria. The urine culture was positive for bacterial growth. The episodes of fever were repeated every 45 days. Accordingly, the patient was diagnosed as a case of recurrent urinary tract infection. In the intervals between her febrile episodes, the patient was healthy and laboratory tests were normal. Ultrasonography, voiding cystourethrogram and dimercaptosuccinic acid scans were normal. During her last visit, the patient mentioned difficulty in swallowing and on examination cervical lymph nodes, exudative tonsillitis and painful aphthous stomatitis were detected. All antibiotics were stopped and corticosteroids were started. The patient's symptoms were relieved and the interval between her febrile episodes became longer.

CONCLUSIONS

Our study shows that a patient should never be marked, particularly when the symptom and signs aren't completely justifying a patient's condition.

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.

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.

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.

Analysis of KSHV B lymphocyte lineage tropism in human tonsil reveals efficient infection of CD138+ plasma cells

Despite 25 years of research, the basic virology of Kaposi Sarcoma Herpesviruses (KSHV) in B lymphocytes remains poorly understood. This study seeks to fill critical gaps in our understanding by characterizing the B lymphocyte lineage-specific tropism of KSHV. Here, we use lymphocytes derived from 40 human tonsil specimens to determine the B lymphocyte lineages targeted by KSHV early during de novo infection in our ex vivo model system. We characterize the immunological diversity of our tonsil specimens and determine that overall susceptibility of tonsil lymphocytes to KSHV infection varies substantially between donors. We demonstrate that a variety of B lymphocyte subtypes are susceptible to KSHV infection and identify CD138+ plasma cells as a highly targeted cell type for de novo KSHV infection. We determine that infection of tonsil B cell lineages is primarily latent with few lineages contributing to lytic replication. We explore the use of CD138 and heparin sulfate proteoglycans as attachment factors for the infection of B lymphocytes and conclude that they do not play a substantial role. Finally, we determine that the host T cell microenvironment influences the course of de novo infection in B lymphocytes. These results improve our understanding of KSHV transmission and the biology of early KSHV infection in a naïve human host, and lay a foundation for further characterization of KSHV molecular virology in B lymphocyte lineages.

KSHV infection is associated with cancer in B cells and endothelial cells, particularly in the context of immune suppression. Very little is known about how KSHV is transmitted and how it initially establishes infection in a new host. Saliva is thought to be the primary route of person-to-person transmission for KSHV, making the tonsil a likely first site for KSHV replication in a new human host. Our study examines KSHV infection in B cells extracted from the tonsils of 40 human donors in order to determine what types of B cells are initially targeted for infection and examine how the presence (or absence) of other immune cells influence the initial stages of KSHV infection. We found that a variety of B cell subtypes derived from tonsils can be infected with KSHV. Interestingly, plasma cells (mature antibody-secreting B cells) were a highly targeted cell type. These results lay the foundation for further studies into the specific biology of KSHV in different types of B cells, an effort that may help us ultimately discover how to prevent the establishment of infection in these cells or reveal new ways to halt the progression of B cell cancers associated with KSHV infection.

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.

The immunology of the periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome; what can the tonsils reveal. A literature review

OBJECTIVES

Tonsillectomy (TE) or adenotonsillectomy (ATE) may have a beneficial effect on the clinical course in children with the periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome. However, an immunological reason for this effect remains unknown. This literature review summarizes the current knowledge regarding the immunological role of the tonsils in the PFAPA syndrome.

METHODS

We searched PubMed, Medline, EMBASE and Cochrane for papers written in English dated from 1 January 1987 to 30 April 2019. The search included all studies reporting histological, immunological or microbiological workup of tonsil specimens from children aged 0-18 years with PFAPA.

RESULTS

Thirteen articles reported histological, immunological or microbiological workup of tonsil specimens in children with PFAPA. The histology of tonsil specimens from children with PFAPA displayed chronic tonsillar inflammation with lymphoid hyperplasia. No uniform immunological pattern was identified, but some studies found fewer B-lymphocytes and smaller germinal centers in PFAPA compared to controls. A difference in tonsillar microbiota between PFAPA and controls was found in one study.

CONCLUSION

A uniform immunological or microbiological pattern explaining the clinical effect of TE in children with PFAPA has not been revealed. Future targeted immunological studies of tonsils in PFAPA patients could possibly illuminate the understanding of the immunology in this disease.

Immune Dysregulation in the Tonsillar Microenvironment of Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA) Syndrome

Periodic Fever, Aphthous stomatitis, Pharyngitis and Adenitis (PFAPA) syndrome is an inflammatory disorder of childhood classically characterized by recurrent fevers, pharyngitis, stomatitis, cervical adenitis, and leukocytosis. While the mechanism is unclear, previous studies have shown that tonsillectomy can be a therapeutic option with improvement in quality of life in many patients with PFAPA, but the mechanisms behind surgical success remain unknown. In addition, long-term clinical follow-up is lacking. In our tertiary care center cohort, 62 patients with PFAPA syndrome had complete resolution of symptoms after surgery (95.3%). Flow cytometric evaluation demonstrates an inflammatory cell population, distinct from patients with infectious pharyngitis, with increased numbers of CD8+ T cells (5.9% vs. 3.8%, p < 0.01), CD19+ B cells (51% vs. 35%, p < 0.05), and CD19+CD20+CD27+CD38-memory B cells (14% vs. 7.7%, p < 0.01). Cells are primed at baseline with increased percentage of IL-1β positive cells compared to control tonsil-derived cells, which require exogenous LPS stimulation. Gene expression analysis demonstrates a fivefold upregulation in IL1RN and TNF expression in whole tonsil compared to control tonsils, with persistent activation of the NF-κB signaling pathway, and differential microbial signatures, even in the afebrile period. Our data indicates that PFAPA patient tonsils have localized, persistent inflammation, in the absence of clinical symptoms, which may explain the success of tonsillectomy as an effective surgical treatment option. The differential expression of several genes and microbial signatures suggests the potential for a diagnostic biomarker for PFAPA syndrome.

Surgical outcomes and unique histological features of tonsils after tonsillectomy in adults with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome

OBJECTIVES

Data on the adult-onset periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome are scarce. European studies reported that unlike pediatric-onset PFAPA, tonsillectomy is ineffective for adult-onset PFAPA. The aims of this study were (1) to assess the response to tonsillectomy in a cohort of Japanese adult-onset PFAPA patients and (2) to evaluate the histologic appearance of tonsils in adult-onset PFAPA patients and to compare them with those of tonsils from age- and sex-matched controls with chronic tonsillitis.

METHODS

In this retrospective cohort study, 5 adults with PFAPA and 15 controls who had undergone tonsillectomy were recruited. The size of the tonsil germinal centers was measured by hematoxylin and eosin staining, and the number and density of B and T lymphocytes in germinal centers were measured by immunohistochemistry, using CD3, CD4 and CD8 as T cell markers and CD20 as B cell marker.

RESULTS

All patients had complete remission of the symptoms after surgery. PFAPA patients had significantly smaller germinal center areas than controls. The number and density of CD8+ cells in germinal centers were significantly lower in tonsils from PFAPA compared with controls. No differences were found between the two groups in CD3+, CD4+, and CD20+ cells. These results are compatible with the tonsillar features of pediatric-onset PFAPA.

CONCLUSION

Our report demonstrates that tonsillectomy might be effective for adult-onset PFAPA and that tonsils of adult- and pediatric-onset PFAPA share the same histological features. These results suggest that the pathogenic mechanisms of adult- and pediatric-onset PFAPA are identical.

Towards better diagnostic criteria for periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome

AIM

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome is the most common cause of a periodic fever in childhood. The exact pathogenesis and the aetiology of PFAPA are still unknown.

METHODS

We conducted a non-systematic review of published articles about PFAPA syndrome and summarised the evidence for diagnostic criteria and treatment options for PFAPA.

RESULTS

The first proposed diagnostic criteria for PFAPA, in addition to periodic fever, included aphthous stomatitis, pharyngitis or cervical lymphadenitis in children younger than five years at the beginning of the symptoms. C-reactive protein (CRP) levels and leucocyte counts increase in most patients during episodes. Recent research reveals that tonsillectomy provides an immediate and long-lasting cure for PFAPA, even in the absence of classic criteria of aphthous stomatitis, pharyngitis or cervical adenitis and in children older than five years.

CONCLUSION

We suggest that PFAPA can be diagnosed in children with at least five regularly occurring fever episodes without any other explanation, even in the absence of aphthous stomatitis, pharyngitis or cervical lymphadenitis and also in children older than five years.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome: main features and an algorithm for clinical practice

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is a recurrent fever syndrome of early childhood with increasing number of adult-onset cases. Although it is a self-limited disease, it may negatively affect the quality of life. The aim of this review is to present a detailed analysis of PFAPA syndrome and an algorithm for diagnosis, therapeutic options, and evaluation of outcome. A comprehensive literature search was conducted through the Cochrane Library, Scopus, and MEDLINE/PubMed databases. The main topics covered are the epidemiology, clinical manifestations, diagnosis, differential diagnosis, etiopathogenesis, genetics, management, disease course and prognosis, disease in adults, unsolved issues, and unmet needs in PFAPA. The diagnosis of PFAPA is mainly based on clinical classification criteria. The most relevant hypothesis for pathogenesis is that dysregulated immune system in a genetically predisposed individual responds to a yet unidentified trigger in an exaggerated way. The pedigree analyses suggest a genetic background for the disease with an autosomal dominant pattern of inheritance. For management, single-dose corticosteroids during attacks and tonsillectomy remain the most effective therapies, while colchicine is a promising option to decrease attack frequency. There remain unsolved issues in PFAPA such as the exact etiopathogenesis and genetic background, the reason why the inflammation is restricted to the oropharyngeal lymphoid tissue, reasons for clock-work regularity of attacks, and self-limited disease course. There is need for a valid diagnostic criteria set with a high performance for both children and adults and consensus on management of PFAPA.

Measles Lymphadenopathy in a Child With PFAPA Syndrome

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is a common cause of periodic fever in children. The pathogenesis of PFAPA is unknown but likely involves immune system dysregulation and may be initiated by an environmental trigger. Tonsillectomy resolves or improves symptoms in some patients, but the reason for this is unknown; moreover, specific abnormalities in tonsillectomy specimens from PFAPA patients have not been described. Here, we report measles virus in tonsil from a child with PFAPA. Measles-type viral cytopathic effect was discovered on histological examination of tonsillar tissue after therapeutic tonsillectomy for PFAPA. Molecular testing showed the left tonsil was positive for measles RNA by reverse transcription polymerase chain reaction (RT-PCR) while the right tonsil was inconclusive (weakly positive). Real-time RT-PCR specific for measles vaccine strain RNA (genotype A) was weakly reactive in the left tonsil tissue when tested in 3 independent replicates, but this result could not be confirmed with conventional genotyping by sequencing. The relationship and clinical significance between measles virus and PFAPA in this case is unclear but may be related to PFAPA-associated immune dysregulation. Additional investigation of measles virus in PFAPA patients would be helpful in further exploring this potential association.

The role of tonsillectomy in the Periodic Fever, Aphthous stomatitis, Pharyngitis and cervical Adenitis syndrome; a literature review

Background

Tonsillectomy (TE) or adenotonsillectomy (ATE) may have a beneficial effect on the clinical course in children with the Periodic Fever, Aphthous stomatitis, Pharyngitis and cervical Adenitis (PFAPA) syndrome. However, an immunological reason for this effect remains unknown. This literature review summarizes the current knowledge of the effect of TE or ATE in the PFAPA syndrome.

Methods

A search of PubMed, Medline, EMBASE and Cochrane was conducted for papers written in English dated from 1 January 1987 to 31 December 2016. The search included all studies reporting outcomes after TE or ATE from children aged 0 to 18 years with PFAPA.

Results

Two randomized controlled trials reported significantly faster resolution of febrile episodes after TE or ATE in children with PFAPA compared to controls (non-surgery groups). We identified 28 case series including 555 children with PFAPA. The diagnosis was set prospectively before surgery in 440 children and retrospectively after surgery in 115 of the children. TE or ATE had a curative effect in 509 of the 555 children with PFAPA (92%), but few studies were of high quality.

Conclusion

TE or ATE may have a curative effect on children with PFAPA, but the evidence is of moderate quality. Further high-quality randomized controlled studies are still needed.

Electronic supplementary material

The online version of this article (10.1186/s12901-017-0049-5) contains supplementary material, which is available to authorized users.

Unique histologic features of tonsils from patients with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome

The objective of this study is to compare the histology and immune cell composition of tonsils from patients with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome to those from patients with obstructive sleep apnea (OSA). Patients with PFAPA and age-matched controls with OSA who had undergone tonsillectomy at Vanderbilt Children's Hospital were recruited. After informed consent, archival paraffin-embedded, formalin-fixed tonsil tissues were obtained. Sizes of major histologic regions were measured. Cores of germinal centers, crypts, and squamous epithelium were assembled on a tissue microarray for immunohistochemical staining and digital image analysis. Features of tonsils from PFAPA and OSA patients were compared with Wilcoxon signed-rank test. Samples from 16 cases with PFAPA and 16 controls with OSA were evaluated. Tonsils from PFAPA cases had significantly smaller germinal centers (0.18 vs. 0.47 mm², p = 0.001) and wider squamous epithelia (176 vs. 138 μm, p = 0.008) than those of OSA patients. The percentages of B and T lymphocytes and myeloid cells were comparable in germinal centers, crypts, and squamous epithelia from PFAPA and OSA patients. Longer time from the last febrile episode in PFAPA cases was associated with larger germinal center area (Spearman's rho = 0.61, p = 0.02). We found differences in the sizes of germinal centers and squamous epithelia in tonsils of patients with PFAPA and OSA, but the cellular compositions within these areas were comparable. Our results suggest that tonsils from patients with PFAPA change histologically over time with enlarging germinal centers following a febrile episode. Additional studies are needed to understand the pathogenesis of PFAPA.

Review of autoinflammatory diseases, with a special focus on periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome

There have been remarkable developments in the field of autoinflammatory diseases over the last 20 years. Research has led to definitions of new conditions, increased understanding of disease mechanisms and specific treatment. The polygenic autoinflammatory condition of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) is the most common autoinflammatory disorder among children in many parts of the world. The clinical features often include clockwork regularity of episodes, prompt responses to corticosteroids and therapeutic effects of tonsillectomy, but the disease mechanisms are largely unknown.

Conclusion

This review discusses the emerging understanding of autoinflammatory diseases, with special emphasis on PFAPA.

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.

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.

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.