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

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.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis recurrence temporally associated with allergen-specific immunotherapy in a female adolescent: a case report

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most common periodic fever syndrome in pediatric patients. It is clinically characterized by fever flares lasting 3-7 days, reappearing every 2-8 weeks with a distinctive clockwork regularity. PFAPA generally begins before 5 years of age and usually ceases 3-5 years after onset. Recurrences may be observed in adolescence and adulthood in up to 20% of cases. The authors aim to describe a case of PFAPA recurrence in adolescence temporally associated with allergen-specific immunotherapy (ASIT). A 16-year-old female patient was referred to the rheumatology unit due to recurrent episodes of fever one month after initiating ASIT for allergic rhinitis. These episodes occurred every 4 weeks and lasted 3 days. During these episodes, she also presented with a sore throat, tonsillar exudates, and cervical lymphadenopathy. Abortive treatment with oral prednisolone was attempted in these episodes, with complete resolution of fever after a single dose. After reviewing her medical background, she had previously experienced febrile episodes accompanied by aphthous ulcers and tonsillar exudates occurring every 7-8 weeks from age 2-7. The etiopathogenesis of PFAPA remains uncertain. Environmental triggers, particularly those with immunomodulator effects, may interfere with the immune responses responsible for PFAPA occurrence, but the mechanisms are still unclear. The authors describe the first report of the reappearance of PFAPA flares, possibly due to ASIT. Further studies are needed to fully clarify if ASIT constitutes a true environmental trigger of PFAPA.

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.

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 [...].

Does having MEFV gene sequence variants affect the clinical course and colchicine response in children with PFAPA syndrome?

The primary aim of this study was to document the treatment modalities used in periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome and look for the efficacy and safety of colchicine in the treatment of PFAPA patients. The secondary aim was to search for whether having MEFV (Mediterranean fever) gene sequence variants affect the clinical course and response to colchicine. The study was conducted in 2 pediatric rheumatology centers. The patients that have been diagnosed with PFAPA syndrome between December 2017 and December 2021 were evaluated retrospectively. The study included 157 patients with PFAPA syndrome (54.8% boys and 45.2% girls). The median follow-up duration was 18 (IQR: 12-30) months. One hundred and fifty-five patients (98.7%) had exudative pharyngitis, 120 patients (76.4%) had aphthous stomatitis, and 82 patients (52.2%) had cervical lymphadenitis during the attacks. Clinical features during attacks were not affected by the presence or absence of the MEFV gene sequence variants. Corticosteroid treatment during attacks was given to 152 patients (96.8%). The frequency of fever attacks did not change in 57 patients (37.5%), increased in 57 patients (37.5%), and decreased in 38 patients (25%) after corticosteroid use. Colchicine was given to 122 patients (77.7%) in the cohort. After colchicine treatment, complete/near-complete resolution of the attacks was observed in 57 patients (46.7%). Colchicine led to partial resolution of the attacks in 59 patients (48.4%). In only 6 patients (4.9%), no change was observed in the nature of the attacks with colchicine treatment. The median duration of the attacks was 4 (IQR: 4-5) days before colchicine treatment, and it was 2 (IQR: 1-2.5) days after colchicine treatment. Also, a significant decrease in the frequency of the attacks was observed before and after colchicine treatment [every 4 (IQR: 3-4) weeks versus every 10 (IQR: 8-24) weeks, respectively, (p < 0.001)]. The overall response to colchicine was not affected by MEFV sequence variants. It was seen that the frequency of fever attacks decreased dramatically in both groups, and children with MEFV variants had significantly less attacks than children without MEFV variants after colchicine treatment (every 11 weeks vs every 9.5 weeks, respectively, p: 0.02).

CONCLUSION

Colchicine seems to be an effective and safe treatment modality in PFAPA treatment. It led to a change in the nature of the attacks either in the frequency, duration, or severity of the attacks in 95.1% of the patients. This study has shown that having MEFV gene sequence variants did not affect the clinical course or response to colchicine. We recommend that colchicine should be considered in all PFAPA patients to see the response of the patient, irrespective of the MEFV gene mutations.

WHAT IS KNOWN

• Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is the most common periodic fever syndrome in the world. Familial Mediterranean fever (FMF) is the most common cause of periodic fever syndrome in Turkey. • Colchicine has become a new treatment option in PFAPA.

WHAT IS NEW

• Some PFAPA patients have Mediterranean fever (MEFV) gene variants, and it is speculated that PFAPA patients with MEFV gene mutations respond better to colchicine. • The aim of this study was to look for this hypothesis. We have seen that the clinical phenotype and colchicine response of PFAPA patients were not affected by MEFV gene sequence variants.

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.

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.

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.

M, Ziaee V. Colchicine versus cimetidine: the better choice for Periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome prophylaxis, and the role of MEFV gene mutations

BACKGROUND

During childhood, the most common periodic fever is periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome. The effective treatment and prevention of febrile attacks improve these patients' and their families' quality of life. However, there is no single strategy or evidence-based guideline to manage this syndrome, and most of them are based on consensus treatment plans.

METHODS

This randomized controlled trial was carried out on 67 PFAPA patients referred to three tertiary centers of pediatric rheumatology. The patients were divided into two groups, including group 1 (n = 36) receiving prednisolone plus colchicine and group 2 (n = 31) receiving prednisolone plus cimetidine. Demographic characteristics and the number of febrile episodes were compared between the two groups before and after the intervention.

RESULTS

In both groups, the number of febrile episodes after the treatment decreased (P ≤ 0.001). Statistical Analysis showed no significant difference between the two groups (P = 0.88). Moreover, 44 patients from both groups were checked for the MEFV gene. There were no statistical differences between MEFV positive and negative subgroups in response to colchicine (P = 1).

CONCLUSION

This study showed that both drug regimens are significantly effective in preventing febrile attacks in PFAPA syndrome, and the presence of a MEFV gene mutation might not be the only significant risk factor for a response to colchicine.

TRIAL REGISTRATION

IRCT, IRCT20191222045847N1. Registered 23 October 2019, https://fa.irct.ir/search/result?query=IRCT20191222045847N1.

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.

Development and implementation of the AIDA International Registry for patients with Periodic Fever, Aphthous stomatitis, Pharyngitis, and cervical Adenitis syndrome

OBJECTIVE

Aim of this paper is to illustrate the methodology, design, and development of the AutoInflammatory Disease Alliance (AIDA) International Registry dedicated to patients with the Periodic Fever, Aphthous stomatitis, Pharyngitis, and cervical Adenitis (PFAPA) syndrome.

METHODS

This is a physician-driven, non-population- and electronic-based registry proposed to gather real-world demographics, clinical, laboratory, instrumental and socioeconomic data from PFAPA patients. Data recruitment is realized through the on-line Research Electronic Data Capture (REDCap) tool. This registry is thought to collect standardized information for clinical research leading to solid real-life evidence. The international scope and the flexibility of the registry will facilitate the realization of cutting-edge study projects through the constant updating of variables and the possible merging and transfer of data between current and future PFAPA registries.

RESULTS

A total of 112 centers have already been involved from 23 countries and 4 continents starting from August 24th, 2021, to April 6th, 2022. In total 56/112 have already obtained the formal approval from their local Ethics Committees. The platform counts 321 users (113 principal investigators, 203 site investigators, two lead investigators, and three data managers). The registry collects retrospective and prospective data using 3,856 fields organized into 25 instruments, including PFAPA patient's demographics, medical histories, symptoms, triggers/risk factors, therapies, and impact on the healthcare systems.

CONCLUSIONS

The development of the AIDA International Registry for PFAPA patients will enable the on-line collection of standardized data prompting real-life studies through the connection of worldwide groups of physicians and researchers. This project can be found on https://clinicaltrials.gov NCT05200715.