Papa R, Bovis F, Federici S, Palmeri S, Bustaffa M , et al.
Arthritis & rheumatology (Hoboken, N.J.) •
To develop evidence-based criteria to classify patients with syndrome of undifferentiated recurrent fevers (SURF). One hundred twelve patients with SURF observed in a single tertiary referral center were analyzed. Patients with genetically confirmed hereditary recurrent fever (HRF) or with periodic fever, aphthosis, pharyngitis, and adenitis (PFAPA) syndrome already analyzed for the Eurofever classification criteria were used as disease controls. A decision tree approach was tested by randomly splitting the available data in a training set and in an internal test set. An alternative model using a classical regression model was also analyzed. An external validation for both approaches was performed on 123 patients recruited from four other centers. The decision tree model integrating clinical and genetic data identified 91% of patients with SURF. A decision tree model based solely on clinical variables identified up to 88% of patients with SURF. The logistic regression model including genetic tests exhibited an overall accuracy of 89.2% (95% confidence interval [CI] 81.1-94.7). In contrast, the logistic regression model exclusively based on clinical manifestations displayed an overall accuracy of 66.7% (95% CI 56.1-76.1). When the classification criteria including genetic tests were applied to the external validation cohort, the model demonstrated a strong discriminative power, with areas under the receiver operating characteristic curve of 96.3% using the decision tree model and 88.0% with the logistic regression model. The study shows the possibility of achieving evidence-based criteria that can classify SURF at least with respect to the main HRF and PFAPA syndrome and may be considered as a preliminary tool for the enrollment of more homogeneous cohorts of patients in future studies.
Vyzhga Y, Wittkowski H, Hentgen V, Georgin-Lavialle S, Theodoropoulou A , et al.
Pediatric rheumatology online journal •
Systemic autoinflammatory disorders (SAIDs) represent a growing spectrum of diseases characterized by dysregulation of the innate immune system. The most common pediatric autoinflammatory fever syndrome, Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA), has well defined clinical diagnostic criteria, but there is a subset of patients who do not meet these criteria and are classified as undefined autoinflammatory diseases (uAID). This project, endorsed by PRES, supported by the EMERGE fellowship program, aimed to analyze the evolution of symptoms in recurrent fevers without molecular diagnosis in the context of undifferentiated AIDs, focusing on PFAPA and syndrome of undifferentiated recurrent fever (SURF), using data from European AID registries. Data of patients with PFAPA, SURF and uSAID were collected from 3 registries including detailed epidemiological, demographic and clinical data, results of the genetic testing and additional laboratory investigations with retrospective application of the modified Marshall and PRINTO/Eurofever classification criteria on the cohort of PFAPA patients and preliminary SURF criteria on uSAID/SURF patients. Clinical presentation of PFAPA is variable and some patients did not fit the conventional PFAPA criteria and exhibit different symptoms. Some patients did not meet the criteria for either PFAPA or SURF, highlighting the heterogeneity within these groups. The study also explored potential overlaps between PFAPA and SURF/uAID, revealing that some patients exhibited symptoms characteristic of both conditions, emphasizing the need for more precise classification criteria. Patients with recurrent fevers without molecular diagnoses represent a clinically heterogeneous group. Improved classification criteria are needed for both PFAPA and SURF/uAID to accurately identify and manage these patients, ultimately improving clinical outcomes.
Vanoni F, Caorsi R, Aeby S, Cochard M, AntĂłn J , et al.
Pediatric rheumatology online journal •
Diagnosis of Periodic Fever, Aphthous stomatitis, Pharyngitis and Cervical Adenitis (PFAPA) syndrome is currently based on the modified Marshall's criteria, but no validated evidence based classification criteria for PFAPA has been established so far. A multistep process, based on the Delphi and Nominal Group Technique was conducted. After 2 rounds of e-mail Delphi survey involving 21 experts in autoinflammation we obtained a list of variables that were discussed in an International Consensus Conference. Variables reaching the 80% of consensus between participants were included in the new classification criteria. In the second phase the new classification criteria and the modified Marshall's criteria were applied on a cohort of 80 pediatric PFAPA patients to compare their performance. The Delphi Survey was sent to 22 participants, 21 accepted to participate. Thirty variables were obtained from the survey and have been discussed at the Consensus Conference. Through the Nominal Group Technique we obtained a new set of classification criteria. These criteria were more restrictive in respect to the modified Marshall's criteria when applied on our cohort of patients. Our work led us to identify a new set of classification criteria for PFAPA syndrome, but they resulted to be too restrictive to be applied in daily clinical practice for the diagnosis of PFAPA.
Dytrych P, Krol P, Kotrova M, Kuzilkova D, Hubacek P , et al.
Molecular immunology •
PFAPA syndrome is a benign, recurrent inflammatory disease of childhood. Tonsillectomy is one of the therapeutic options with a yet unexplained biological mechanism. We tested whether specific lymphocyte subsets recruited from blood to human tonsils participate in PFAPA pathogenesis. Paired tonsils/peripheral blood (PB) samples were investigated (a) from children with PFAPA that successfully resolved after tonsillectomy (n=10) (b) from children with obstructive sleep apnoea syndrome as controls (n=10). The lymphocyte profiles were analysed using 8-colour flow cytometry, immunoglobulin (IGH) and T-cell receptor (TCR) gene rearrangements via PCR and next generation sequencing; a TREC/KREC analysis was performed using qPCR. The PFAPA tonsils in the asymptomatic phase had a lower percentage of B-lymphocytes than controls; T-lymphocyte counts were significantly higher in PB. The percentages of cytotoxic CD8pos T-lymphocytes were approximately 2-fold higher in PFAPA tonsils; the transitional B cells and naĂŻve stages of both the CD4pos and CD8pos T-lymphocytes with a low expression of PD-1 molecule and high numbers of TREC were also increased. With the exception of elevated plasmablasts, no other differences were significant in PB. The expression levels of CXCL10, CXCL9 and CCL19 genes were significantly higher in PFAPA tonsils. The IGH/TCR pattern showed no clonal/oligoclonal expansion. DNA from the Epstein-Barr virus, Human Herpervirus-6 or adenovirus was detected in 7 of 10 PFAPA tonsils but also in 7 of 9 controls. Our findings suggest that the uninhibited, polyclonal response of newly derived lymphocytes participate in the pathogenesis of PFAPA. Because most of the observed changes were restricted to tonsils and were not present in PB, they partly explain the therapeutic success of tonsillectomy in PFAPA syndrome.
Król P, Böhm M, Sula V, Dytrych P, Katra R , et al.
Clinical and experimental rheumatology •
This paper aims to describe clinical and laboratory features and disease outcome in a single-centre cohort of patients with PFAPA syndrome (Periodic Fever, Aphtous stomatitis, Pharyngitis, and Adenitis) and to test performance of diagnostic and therapeutic algorithms. Patients fulfilling criteria were selected from the fever clinic population. Prospective follow-up together with recruitment of newly diagnosed patients followed pre-defined guidelines. Diagnostic and therapeutic algorithms and definitions of outcome and therapy response were formulated. Paired blood samples during febrile and afebrile periods were compared. Out of 176 patients referred for suspected periodic fever 125 children fulfilled criteria. Their age at onset was 23 months, median episode duration 3.5 days at 4-week intervals. Fever was associated with pharyngitis (91%), cervical adenitis (78%) and aphtae (41%). Among therapeutic options, episodic prednisone proved to be the most common first-line treatment. Administered to 77 patients, it reduced symptoms in 94%. Tonsillectomy led to the full symptom resolution in all 18 patients. Forty-six patients reached disease remission. Distribution of typical symptoms, response to therapies and disease outcome in a large patient cohort were documented. We offer diagnostic and therapeutic algorithms that have proven effective during this prospective trial. Our findings support the general belief of benign nature of this aetiologically unclear condition, despite proportion of patients having persistent disease for years. Maintenance of normal findings in afebrile intervals, striking response to a single dose of prednisone and normal growth and development together with spontaneous tendency towards prolongation of afebrile intervals are important confirmatory features of PFAPA syndrome.
