National Institutes of Health

12
PFAPA Syndrome Publications
28
PFAPA Syndrome Researchers

Publications

Features Associated with Response to Tonsillectomy in Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis Syndrome in Children.

Manthiram K, Ortega-Villa AM, Lapidus S, Bowes M, Romeo T , et al.
The Journal of pediatrics •

To identify clinical features associated with response to tonsillectomy among children with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome and to determine optimal management of children with continued episodes after tonsillectomy. Patients with PFAPA seen at Vanderbilt University Children's Hospital and the National Institutes of Health (NIH) who underwent tonsillectomy were enrolled and queried regarding symptoms before and after surgery. Ninety-seven subjects with PFAPA (43 Vanderbilt, 54 NIH) were followed for a median of 49 months following tonsillectomy. Nearly half of participants reported complete resolution of PFAPA episodes (65% at Vanderbilt and 35% at NIH), while 25% had less severe or frequent episodes, 23% had a period of remission with recurrence, and 4% had no change in episodes. By logistic regression, factors associated with a full response to tonsillectomy were episode resolution with glucocorticoid treatment, presence of exudative pharyngitis, absence of rash, and absence of arthralgia/myalgia during pre-tonsillectomy PFAPA flares. Among those requiring treatment for persistent flares post-tonsillectomy, 15/19 (79%) reported improvement with cimetidine or famotidine prophylaxis. Tonsillectomy remains effective in improving PFAPA flares in most patients. However, unique episode features prior to tonsillectomy appear to be clinical predictors of response to tonsillectomy. Histamine receptor 2 antagonists like cimetidine were effective prophylactic agents for refractory cases post-tonsillectomy. Patients with incomplete response to tonsillectomy may represent a subset of PFAPA with unique factors affecting their pathogenesis.

Increase in pediatric recurrent fever evaluations during the first year of the COVID-19 pandemic in North America.

Mansfield LM, Lapidus SK, Romero SN, Moorthy LN, Adler-Shohet FC , et al.
Frontiers in pediatrics •

The impact of the COVID-19 pandemic on new diagnoses of recurrent fevers and autoinflammatory diseases is largely unknown. The Childhood Arthritis and Rheumatology Research Alliance (CARRA) PFAPA/AID Working Group aimed to investigate the impact of the COVID-19 pandemic on the number of pediatric patients evaluated for recurrent fevers and autoinflammatory diseases in North America. The absolute number of new outpatient visits and the proportion of these visits attributed to recurrent fever diagnoses during the pre-pandemic period (1 March 2019-29 February 2020) and the first year of the COVID-19 pandemic (1 March 2020-28 February 2021) were examined. Data were collected from 27 sites in the United States and Canada. Our results showed an increase in the absolute number of new visits for recurrent fever evaluations in 21 of 27 sites during the COVID-19 pandemic compared to the pre-pandemic period. The increase was observed across different geographic regions in North America. Additionally, the proportion of new visits to these centers for recurrent fever in relation to all new patient evaluations was significantly higher during the first year of the pandemic, increasing from 7.8% before the pandemic to 10.9% during the pandemic year ( < 0.001). Our findings showed that the first year of the COVID-19 pandemic was associated with a higher number of evaluations by pediatric subspecialists for recurrent fevers. Further research is needed to understand the reasons behind these findings and to explore non-infectious triggers for recurrent fevers in children.

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

Wang A, Manthiram K, Dedeoglu F, Licameli GR
World journal of otorhinolaryngology - head and neck surgery •

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.

Spectrum of Systemic Auto-Inflammatory Diseases in India: A Multi-Centric Experience.

Suri D, Rawat A, Jindal AK, Vignesh P, Gupta A , et al.
Frontiers in immunology •

Systemic autoinflammatory diseases (SAID) are rare inherited disorders involving genes regulating innate immune signaling and are characterized by periodic or chronic multi-systemic inflammation. To describe spectrum of clinical, immunological, molecular features, and outcomes of patients with SAID in India. Request to share data was sent to multiple centers in India that are involved in care and management of patients with Inborn Errors of Immunity. Six centers provided requisite data that were compiled and analyzed. Data on 107 patients with SAID were collated-of these, 29 patients were excluded due to unavailability of complete information. Twelve patients (15%) had type 1 interferonopathies, 21 (26%) had diseases affecting inflammasomes, 30 patients (41%) had non-inflammasome related conditions and 1five patients (19%) had Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA). Type1 interferonopathies identified in the cohort included patients with Deficiency of Adenosine Deaminase 2 ( (six patients; five families); STING-associated vasculopathy infantile-onset (SAVI) (three patients, one family); Spondyloenchondro-dysplasia with Immune Dysregulation (SPENCD) (two patients). Diseases affecting inflammasomes include Mevalonate Kinase Deficiency (eight patients); Cryopyrin-Associated Periodic Syndromes (CAPS) (seven patients); NLR Family, Pyrin domain-containing 12 NLRP12) (two patients); Familial Mediterranean fever (FMF) (two patients); Autoinflammation and PLCG-associated antibody deficiency and immune dysregulation (APLAID) (two patients). TNF receptor-associated periodic syndrome (TRAPS) (three patients); A20 haploinsufficiency (four patients); Deficiency of Interleukin 1 Receptor Antagonist (DIRA) (two patients) were categorized as non-inflammasome related conditions. There were significant delays in diagnosis Corticosteroids and other immunosuppressive agents were used for treatment as anti-IL-1 drugs and other biological agents were and still are not available in India. Eight (16.3%) patients had so far succumbed to their illness. This is the first nationwide cohort of patients with SAID from India. Clinical manifestations were diverse. Overlapping of clinical features with other relatively common rheumatological disorders often resulted in delays in diagnosis. More nationwide efforts are needed to enhance awareness of SAID among health care professionals and there is an urgent need to make targeted immunotherapies universally available.

Classification criteria for autoinflammatory recurrent fevers.

Gattorno M, Hofer M, Federici S, Vanoni F, Bovis F , et al.
Annals of the rheumatic diseases •

Different diagnostic and classification criteria are available for hereditary recurrent fevers (HRF)-familial Mediterranean fever (FMF), tumour necrosis factor receptor-associated periodic fever syndrome (TRAPS), mevalonate kinase deficiency (MKD) and cryopyrin-associated periodic syndromes (CAPS)-and for the non-hereditary, periodic fever, aphthosis, pharyngitis and adenitis (PFAPA). We aimed to develop and validate new evidence-based classification criteria for HRF/PFAPA. Step 1: selection of clinical, laboratory and genetic candidate variables; step 2: classification of 360 random patients from the Eurofever Registry by a panel of 25 clinicians and 8 geneticists blinded to patients' diagnosis (consensus ≥80%); step 3: statistical analysis for the selection of the best candidate classification criteria; step 4: nominal group technique consensus conference with 33 panellists for the discussion and selection of the final classification criteria; step 5: cross-sectional validation of the novel criteria. The panellists achieved consensus to classify 281 of 360 (78%) patients (32 CAPS, 36 FMF, 56 MKD, 37 PFAPA, 39 TRAPS, 81 undefined recurrent fever). Consensus was reached for two sets of criteria for each HRF, one including genetic and clinical variables, the other with clinical variables only, plus new criteria for PFAPA. The four HRF criteria demonstrated sensitivity of 0.94-1 and specificity of 0.95-1; for PFAPA, criteria sensitivity and specificity were 0.97 and 0.93, respectively. Validation of these criteria in an independent data set of 1018 patients shows a high accuracy (from 0.81 to 0.98). Eurofever proposes a novel set of validated classification criteria for HRF and PFAPA with high sensitivity and specificity.

An international delphi survey for the definition of the variables for the development of new classification criteria for periodic fever aphtous stomatitis pharingitis cervical adenitis (PFAPA).

Vanoni F, Federici S, Antón J, Barron KS, Brogan P , et al.
Pediatric rheumatology online journal •

Diagnosis of Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) is currently based on a set of criteria proposed in 1999 modified from Marshall's criteria. Nevertheless no validated evidence based set of classification criteria for PFAPA has been established so far. The aim of this study was to identify candidate classification criteria PFAPA syndrome using international consensus formation through a Delphi questionnaire survey. A first open-ended questionnaire was sent to adult and pediatric clinicians/researchers, asking to identify the variables thought most likely to be helpful and relevant for the diagnosis of PFAPA. In a second survey, respondents were asked to select, from the list of variables coming from the first survey, the 10 features that they felt were most important, and to rank them in descending order from most important to least important. The response rate to the first and second Delphi was respectively 109/124 (88%) and 141/162 (87%). The number of participants that completed the first and second Delphi was 69/124 (56%) and 110/162 (68%). From the first Delphi we obtained a list of 92 variables, of which 62 were selected in the second Delphi. Variables reaching the top five position of the rank were regular periodicity, aphthous stomatitis, response to corticosteroids, cervical adenitis, and well-being between flares. Our process led to identification of features that were felt to be the most important as candidate classification criteria for PFAPA by a large sample of international rheumatologists. The performance of these items will be tested further in the next phase of the study, through analysis of real patient data.

Unraveling the pathogenesis of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis through genetic, immunologic, and microbiologic discoveries: an update.

Manthiram K, Lapidus S, Edwards K
Current opinion in rheumatology •

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is considered the most common periodic fever syndrome of childhood. Although it was first described three decades ago, the pathogenesis has been poorly understood. Recent studies on the heritability and immunology of the disorder have begun to shed light into the mechanisms of this autoinflammatory disorder. This review will focus on the pathogenesis of PFAPA, especially as it pertains to the genetic susceptibility, tonsillar immunology, and the role of the microbiome. Recent literature provides insights into the heritability, potential genetic modifiers, and the immunologic and microbiological profile of the tonsils in this syndrome. Evidence is mounting that PFAPA is inherited as a complex genetic disease. Furthermore, tonsillectomy is curative in the majority of patients, including those who do not meet the complete clinical criteria for PFAPA. The tonsils in PFAPA patients may exhibit unique immunologic and microbiological features. The goal of this review is to outline these new developments.

Physicians' perspectives on the diagnosis and management of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome.

Manthiram K, Li SC, Hausmann JS, Amarilyo G, Barron K , et al.
Rheumatology international •

To assess the practice patterns of pediatric rheumatology and infectious diseases subspecialists in the diagnosis and treatment of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome. An online survey assessing diagnostic and treatment approaches was sent to 424 members of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) and 980 members of the Pediatric Infectious Disease Society (PIDS). 277 physicians (123 from CARRA and 154 from PIDS representing 21% of the total membership) completed the survey. To diagnose PFAPA, most respondents agreed that patients must have the following features of the diagnostic criteria: stereotypical fever episodes (95%), asymptomatic intervals between episodes (93%), and normal growth and development (81%). However, 71% of the respondents did not require age of onset <5 years, 33% did not require regular intervals between episodes, and 79% did not require the concomitant signs of aphthous stomatitis, adenitis, or pharyngitis during episodes as long as episodes were regular. Over half (58%) considered episode resolution with steroids to be diagnostic of PFAPA. Corticosteroids, antipyretics, tonsillectomy, and cimetidine were the most commonly prescribed treatments, while steroids and tonsillectomy were most effective. Subspecialists in pediatric rheumatology and infectious diseases showed limited adherence to the complete published criteria for diagnosing PFAPA suggesting heterogeneity in the characteristics of patients diagnosed with the disorder. These findings emphasize the need to develop consensus diagnostic and treatment guidelines in well-characterized patient populations.

Proceedings of the 2016 Childhood Arthritis and Rheumatology Research Alliance (CARRA) Scientific Meeting : Toronto, Canada. 14-17 April 2016.

Fotis L, Shaikh N, Baszis K, French A, Tarr P , et al.
Pediatric rheumatology online journal •

P1 Serologic evidence of gut-driven systemic inflammation in juvenile idiopathic arthritis Lampros Fotis, Nur Shaikh, Kevin Baszis, Anthony French, Phillip Tarr P2 Oral health and anti-citrullinated peptide antibodies (ACPA) in juvenile idiopathic arthritis Sriharsha Grevich, Peggy Lee, Sarah Ringold, Brian Leroux, Hannah Leahey, Megan Yuasa, Jessica Foster, Jeremy Sokolove, Lauren Lahey, William Robinson, Joshua Newsom, Anne Stevens P3 Novel autoantigens for endothelial cell antibodies in pediatric rheumatic diseases identified by proteomics Rie Karasawa, Mayumi Tamaki, Megumi Tanaka, Toshiko Sato, Kazuo Yudoh, James N. Jarvis P4 Transcriptional profiling reveals monocyte signature associated with JIA patient poor response to methotrexate Halima Moncrieffe, Mark F. Bennett, Monica Tsoras, Lorie Luyrink, Huan Xu, Sampath Prahalad, Paula Morris, Jason Dare, Peter A. Nigrovic, Margalit Rosenkranz, Mara Becker, Kathleen M. O’Neil, Thomas Griffin, Daniel J. Lovell, Alexei A. Grom, Mario Medvedovic, Susan D. Thompson P5 A multi-dimensional genomic map for polyarticular juvenile idiopathic arthritis Lisha Zhu, Kaiyu Jiang, Laiping Wong, Michael J Buck, Yanmin Chen, Halima Moncrieffe, Laura Brungs, Tao Liu, Ting Wang, James N Jarvis P6 Tocilizumab for treatment of children with refractory JIA Khaled Alsaeid, Jasim Alfailakawi, Hamid Alenezi, Hazim Alsaeed P7 Clinical characteristics of the initial patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Registry Tim Beukelman, Marc Natter, Norm Ilowite, Kelly Mieszkalski, Grendel Burrell, Brian Best, Helen Bristow, Shannon Carr, Anne Dennos, Rachel Kaufmann, Yukiko Kimura, Laura Schanberg P8 Comparative performance of small and large clinical centers in a comprehensive pediatric rheumatology disease registry Peter R Blier P9 Clinical characteristics of children with membranous lupus nephritis: The Childhood Arthritis and Rheumatology Research Alliance Legacy Registry Alexis Boneparth, Scott E. Wenderfer, L. Nandini Moorthy, Suhas M. Radhakrishna, Anna Carmela P. Sagcal-Gironella, Emily von Scheven P10 Rituximab use in pediatric lupus anticoagulant hypoprothrombinemia syndrome - a two center experience Kader Cetin Gedik, Salma Siddique, Cassyanne L. Aguiar, Doruk Erkan P11 Predictors of complementary and alternative medicine use and response in children with musculoskeletal conditions Ezra Cohen, Yvonne Lee, Michelle Dossett, Darshan Mehta, Roger Davis P12 Comparison of pediatric rheumatology and nephrology survey results for the treatment of refractory proliferative lupus nephritis and renal flare in juvenile SLE Mileka Gilbert, Beatrice Goilav, Esra Meidan, Joyce Hsu, Alexis Boneparth, Anabelle Chua, Stacy Ardoin, Scott E. Wenderfer, Emily Von Scheven, Natasha M. Ruth P13 Transitioning lupus patients from pediatric to adult rheumatology Joyce Hui-Yuen, Kader Cetin Gedik, Liza Bermudez, Ashlea Cook, Lisa Imundo, Amy Starr, Andrew Eichenfield, Anca Askanase P14 The systemic juvenile idiopathic arthritis cohort of the Childhood Arthritis & Rheumatology Research Alliance Registry Ginger Janow, Laura E. Schanberg, Soko Setoguchi, Victor Hasselblad, Elizabeth D. Mellins, Rayfel Schneider, Yukiko Kimura, The CARRA Legacy Registry Investigators P15 Results of the pilot study of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) consensus treatment plans for new-onset systemic juvenile idiopathic arthritis Yukiko Kimura, Sriharsha Grevich, Timothy Beukelman, Esi Morgan, T Brent Graham, Maria Ibarra, Yonit Sterba Ruas, Marisa Klein-Gitelman, Karen Onel, Sampath Prahalad, Marilynn Punaro, Sarah Ringold, Dana Toib, Heather Van Mater, Jennifer E. Weiss, Pamela F. Weiss, Kelly Mieszkalski, Laura E. Schanberg P16 A systemic review of pain relief modalities in juvenile idiopathic arthritis: First step in developing a novel decision support intervention Timothy S. H. Kwok, Jacinthe Bisaillon, Christine Smith, Lucie Brosseau, Jennifer Stinson, Adam M. Huber, Ciaran M. Duffy, Karine Toupin April P17 Barriers and facilitators to care retention for pediatric systemic lupus erythematous patients in South Africa: A qualitative study Laura B Lewandowski, Christiaan Scott P18 Evaluating the feasibility of conducting comparative effectiveness studies in juvenile Localized Scleroderma (jLS) Suzanne C. Li, Kathryn S. Torok, C. Egla Rabinovich, Sandy D. Hong, Mara L Becker, Fatma Dedeoglu, Maria F. Ibarra, Polly J Ferguson, Rob C. Fuhbrigge, Katie G. Stewart, Elena Pope, Ronald M. Laxer, Thomas G. Mason, Gloria C. Higgins, Xiaohu Li, Marilynn G. Punaro, George Tomlinson, Eleanor Pullenayegum, John Matelski, Laura Schanberg, Brian M. Feldman P19 Tonsillar histology in patients with periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome Kalpana Manthiram, Hernan Correa, Kathryn Edwards P20 Clinical course of juvenile dermatomyositis presenting as skin predominant disease Edward J. Oberle, Michelle Bayer, Dominic O. Co, Hatice Ezgi Baris, Yvonne Chiu, Adam Huber, Susan Kim P21 A Survey of musculoskeletal ultrasound practices of pediatric rheumatologists in North America Edward J Oberle, Timothy Beukelman P22 Assessment, classification and treatment of calcinosis as a complication of juvenile dermatomyositis: A survey of pediatric rheumatologists by the Childhood Arthritis and Rheumatology Research Alliance Amir B. Orandi, Kevin W. Baszis, Vikas Dharnidharka, Mark F. Hoeltzel, for the CARRA JDM Committee P23 CARRA dermatomyositis CTP pilot study Ann Reed, Adam Huber, George Tomlinson, Eleanor Pullenayegum, John Matelski, Y. Ingrid Goh, Laura Schanberg, Brian M. Feldman P24 Unexpectedly high incidences and prolonged disease activity in children with chronic non-bacterial osteomyelitis (CNO) as compared to bacterial osteomyelitis Anja Schnabel, Ursula Range, Gabriele Hahn, Timo Siepmann, Reinhard Berner, Christian Michael Hedrich P25 Juvenile systemic sclerosis cohort within the Childhood Arthritis and Rheumatology Research Alliance (CARRA) Legacy Registry: Follow up characteristics Brandi Stevens, Kathryn S. Torok, Suzanne Li, Nicole Hershey, Megan Curran, Gloria Higgins, Katharine Moore, Egla Rabinovich, Anne M. Stevens, for the CARRA Registry Investigators P26 Development and usability testing of an iPad and desktop psycho-educational game for children with Juvenile Idiopathic Arthritis and their parents Jennifer Stinson, Mark Connelly, Adam Huber, Nadia Luca, Lynn Spiegel, Argerie Tsimicalis, Stephanie Luca, Naweed Tajuddin, Roberta Berard, Julia Barsalou, Sarah Campillo, Paul Dancey, Ciaran Duffy, Brian Feldman, Nicole Johnson, Patrick McGrath, Natalie Shiff, Shirley Tse, Lori Tucker, Charles Victor P27 : User-centred design and development of a smartphone app to support self-management for youth with arthritis pain Jennifer Stinson, Chitra Lalloo, Lauren Harris, Joseph Cafazzo, Lynn Spiegel, Brian Feldman, Nadia Luca, Ronald Laxer P28 Accessing pediatric rheumatology care: Despite barriers, few parents prefer telemedicine Danielle R. Bullock, Richard K. Vehe, Lei Zhang, Colleen K. Correll P29 Exploration of factors contributing to time to achieve clinically inactive disease (CID) in juvenile idiopathic arthritis (JIA): A preliminary report Suhas Ganguli, Max Shenberger, Ritesh Korumilli, Beth Gottlieb P30 Pediatric rheumatology referral patterns: Presenting complaints of new patients at a large, urban academic center Martha Rodriguez, Deirdre de Ranieri, Karen Onel, Linda Wagner-Weiner, Melissa Tesher P31 Quality improvement (QI) initiatives in childhood systemic lupus erythematosus (cSLE) Elizabeth Roth Wojcicki, Kristyn L. Maletta, Dominic O. Co, Marsha Malloy, Sarah Thomson, Judyann C. Olson P32 Proliferative lupus nephritis in juvenile SLE: Support from the pediatric nephrology community for the definitions of responsiveness and flare in the 2012 consensus treatment plans Scott E. Wenderfer, Mileka Gilbert, Joyce Hsu, Sangeeta Sule, Tamar B. Rubinstein, Beatrice Goilav, Daryl M. Okamura, Annabelle Chua, Laurence A. Greenbaum, Jerome C. Lane, Emily von Scheven, Stacy P. Ardoin, Natasha M. Ruth P33 The steroid taper app: Making of a mobile app Jennifer M. P. Woo, Marsha M. Malloy, James A. Jegers, Dustin J. Hahn, Mary K. Hintermeyer, Stacey M. Martinetti, Gretchen R. Heckel, Elizabeth L. Roth-Wojcicki, Dominic O. Co

Advances in the genetically complex autoinflammatory diseases.

Ombrello MJ
Seminars in immunopathology •

Monogenic diseases usually demonstrate Mendelian inheritance and are caused by highly penetrant genetic variants of a single gene. In contrast, genetically complex diseases arise from a combination of multiple genetic and environmental factors. The concept of autoinflammation originally emerged from the identification of individual, activating lesions of the innate immune system as the molecular basis of the hereditary periodic fever syndromes. In addition to these rare, monogenic forms of autoinflammation, genetically complex autoinflammatory diseases like the periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome, chronic recurrent multifocal osteomyelitis (CRMO), Behçet's disease, and systemic arthritis also fulfill the definition of autoinflammatory diseases-namely, the development of apparently unprovoked episodes of inflammation without identifiable exogenous triggers and in the absence of autoimmunity. Interestingly, investigations of these genetically complex autoinflammatory diseases have implicated both innate and adaptive immune abnormalities, blurring the line between autoinflammation and autoimmunity. This reinforces the paradigm of concerted innate and adaptive immune dysfunction leading to genetically complex autoinflammatory phenotypes.

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) is a disorder of innate immunity and Th1 activation responsive to IL-1 blockade.

Stojanov S, Lapidus S, Chitkara P, Feder H, Salazar JC , et al.
Proceedings of the National Academy of Sciences of the United States of America •

The syndrome of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) is the most common periodic fever disease in children. However, the pathogenesis is unknown. Using a systems biology approach we analyzed blood samples from PFAPA patients whose genetic testing excluded hereditary periodic fevers (HPFs), and from healthy children and pediatric HPF patients. Gene expression profiling could clearly distinguish PFAPA flares from asymptomatic intervals, HPF flares, and healthy controls. During PFAPA attacks, complement (C1QB, C2, SERPING1), IL-1-related (IL-1B, IL-1RN, CASP1, IL18RAP), and IFN-induced (AIM2, IP-10/CXCL10) genes were significantly overexpressed, but T cell-associated transcripts (CD3, CD8B) were down-regulated. On the protein level, PFAPA flares were accompanied by significantly increased serum levels of chemokines for activated T lymphocytes (IP-10/CXCL10, MIG/CXCL9), G-CSF, and proinflammatory cytokines (IL-18, IL-6). PFAPA flares also manifested a relative lymphopenia. Activated CD4(+)/CD25(+) T-lymphocyte counts correlated negatively with serum concentrations of IP-10/CXCL10, whereas CD4(+)/HLA-DR(+) T lymphocyte counts correlated positively with serum concentrations of the counterregulatory IL-1 receptor antagonist. Based on the evidence for IL-1β activation in PFAPA flares, we treated five PFAPA patients with a recombinant IL-1 receptor antagonist. All patients showed a prompt clinical and IP-10/CXCL10 response. Our data suggest an environmentally triggered activation of complement and IL-1β/-18 during PFAPA flares, with induction of Th1-chemokines and subsequent retention of activated T cells in peripheral tissues. IL-1 inhibition may thus be beneficial for treatment of PFAPA attacks, with IP-10/CXCL10 serving as a potential biomarker.