Buttarelli M, Rapari G, Riccio M, Manna R, Rigante D , et al.
International journal of molecular sciences •
Autoinflammatory diseases involve recurrent systemic inflammation caused by dysregulated innate immunity, arising from genetic or multifactorial mechanisms, as seen in periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome. About 10% of PFAPA patients show autosomal dominant inheritance. We describe a three-generation family with a PFAPA-like recurrent fever syndrome displaying clear autosomal dominant transmission. All affected individuals tested negative on a diagnostic panel of 13 known autoinflammatory genes. Whole-exome sequencing was performed in two distantly related affected members, followed by variant filtering, segregation analysis, and phenotype-based prioritization. A single heterozygous missense variant in , c.154G>A p.(Asp52Asn), co-segregated with disease in all affected relatives. This variant is extremely rare in population databases, absent from ClinVar, present in COSMIC, and predicted as damaging by REVEL and CADD. RXFP1, not previously implicated in autoinflammatory or innate immune disorders, encodes the relaxin family peptide receptor 1, a G protein-coupled receptor involved in extracellular matrix regulation, anti-fibrotic pathways, and modulation of inflammatory cytokine production. Protein network analysis showed interactions with RLXN1-3, inflammatory mediators, PTGDR, ADORA2B, and C1QTNF8, supporting an immunomodulatory function. This is the first report linking variation to a hereditary recurrent fever syndrome, identifying relaxin signalling as a potential immune regulatory pathway.
The underlying mechanisms responsible for the periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome are unknown. The main purpose of this study was to retrospectively assess different characteristics and lab-work investigations including serum 25(OH)-vitamin D levels in patients with PFAPA syndrome evaluated at our University hospital during the decade 2014-2024. The medical charts of 151 children with diagnosis of PFAPA syndrome were retrospectively evaluated: for each patient demographic data, clinical manifestations during acute episodes, and laboratory analyses during a well-being phase within the trimester following PFAPA diagnosis were examined. A focus was given to serum 25-hydroxyvitamin D [25(OH)-vitamin D] concentration, recognized as the functional status indicator for vitamin D. Based on the reference values for normal serum 25(OH)-vitamin D, patients were divided into two groups (inadequate versus normal vitamin D levels); the groups were compared to identify if hypovitaminosis D could have any relationship with the evolution of PFAPA syndrome over time. Forty-five PFAPA patients (30% of the whole cohort) had serum 25(OH)-vitamin D below the normal reference (< 30 ng/mL), and inadequate vitamin D serum levels were associated with a persistent pattern of PFAPA syndrome, also showing an inverse correlation with age at disease onset. This study offers a static snapshot of vitamin D status in children with PFAPA syndrome, without accounting for specific time points, and suggests that serum 25(OH)-vitamin D levels might contribute to a longer duration of the recurring PFAPA symptoms.
Sicignano LL, Rigante D, Moccaldi B, Massaro MG, Delli Noci S , et al.
Advances in therapy •
Analogies or differences of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome in children and adults are barely known. The aim of our study was to compare the overall characteristics of a large cohort of patients, both children and adults, diagnosed with PFAPA syndrome. In the last decade, we identified 120 children and 63 adults with periodically recurring fevers, who fulfilled the criteria for PFAPA diagnosis. The two subcohorts were analyzed according to demographic features, clinical manifestations, laboratory data, and responses to therapies. The mean age of onset was 2.4 ± 1.5 and 19.7 ± 10.3 years, respectively, in children and adults, while attacks occurred every 3.8 ± 0.8 and every 4.3 ± 2.3 weeks, respectively, in children and adults. A higher prevalence of exudative pharyngitis was observed in children (58.8%), and the majority of children had only two cardinal signs during flares. In adults, there was a higher interpersonal variability of the intercritical periods. Inflammatory markers measured during non-febrile periods were normal in children but altered in the totality of adults during febrile periods. A strong efficacy of corticosteroids in controlling the pediatric syndrome was observed, but response rates to steroids were less brilliant in adults. Colchicine and interleukin-1 inhibitors were used in the management of the steroid-resistant adult syndrome. Conversely, tonsillectomy was performed in a very low number of children, but was effective in 60.7% of adults when treated after 16 years. The mean age of disappearance of PFAPA symptoms has been 6.4 ± 2.4 years in children, while only 27% of adults have shown a complete drug-free symptom regression. A linear conformity of the PFAPA syndrome has been observed between pediatric and adult patients. PFAPA symptoms tended to disappear with no sequelae in 94.1% of children, while the disease was still active in almost 3/4 of adults at the time of our assessment.
Soriano A, Soriano M, Espinosa G, Manna R, Emmi G , et al.
Frontiers in immunology •
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.
Sangiorgi E, Azzarà A, Molinario C, Pietrobono R, Rigante D , et al.
European journal of human genetics : EJHG •
PFAPA is an autoinflammatory syndrome characterized by periodic fever, aphthous stomatitis, sterile pharingitis, and adenitis, with an onset usually before the age of five. While the condition is most commonly sporadic, a few cases are familial and are usually compatible with an autosomal dominant (AD) transmission pattern, with reduced penetrance in some pedigrees. We performed exome analysis in a family where PFAPA was present in three relatives in two generations showing apparent AD segregation, identifying several rare and/or novel heterozygous variants in genes involved in the autoinflammatory pathway. Following segregation analysis of candidate variants, only one, c. 2770T>C p.(S924P) in the ALPK1 gene, was found to be consistently present in affected family members. ALPK1 is broadly expressed in different tissues and its protein is the intracellular kinase activated by the bacterial ADP-heptose bisphosphate that phosphorylates and activates TRAF-Interacting protein with Forkhead-Associated domain (TIFA) and triggers the immediate response to Gram-negative bacterial invasion. Sequencing analysis of 13 additional sporadic cases and 10 familial PFAPA cases identified two additional heterozygous missense variants c.1024G>C p.(D342H) and c.710C>T p.(T237M) in two sporadic patients, suggesting that rare variants in ALPK1 may represent a predisposing factor for recurrent periodic fever in a pediatric population.
Cantarini L, Vitale A, Sicignano LL, Emmi G, Verrecchia E , et al.
Frontiers in immunology •
To identify a set of variables that could discriminate patients with adult-onset periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome from subjects with fever of unknown origin (FUO). We enrolled 74 adults diagnosed with PFAPA syndrome according to the currently used pediatric diagnostic criteria and 62 additional patients with FUO. After having collected clinical and laboratory data from both groups, univariate and multivariate analyses were performed to identify the variables associated with PFAPA diagnosis. Odds ratio (OR) values, their statistical significance, and corresponding 95% confidence interval (CI) were evaluated for each diagnostic factor both at the univariate and multivariate analyses. Diagnostic accuracy was evaluated by the area under receiver operating characteristic (ROC) curve, while the leave-one-out cross-validation procedure was used to ensure that the model maintains the same diagnostic power when applied to new data. According to the multivariate analysis, the clinical variables that discriminated PFAPA patients were: fever episodes associated with cervical lymphadenitis (OR = 92; < 0.0001), fever attacks associated with erythematous pharyngitis (OR = 231; < 0.0001), increased inflammatory markers during fever attacks (OR = 588; = 0.001), and the lack of clinical and laboratory signs of inflammation between flares (OR = 1202; < 0.0001). These variables were considered for a diagnostic model which accounted for their OR values. The diagnostic accuracy of the proposed set of criteria corresponded to an area under ROC curve of 0.978 (95% CI 0.958-0.998), with a model sensitivity and specificity equal to 93.4% (95% CI 87.5-96.5%) and 91.7% (95% CI 82.8-96.7%), respectively. we have provided herein a set of clinical diagnostic criteria for adult-onset PFAPA syndrome. Our criteria represent an easy-to-use diagnostic tool aimed at identifying PFAPA patients among subjects with FUO with a high-predictive potential, as shown by its very high sensitivity and specificity.