Syndrome of Undifferentiated Recurrent Fever (SURF): An Emerging Group of Autoinflammatory Recurrent Fevers

Could tocilizumab be used in familial Mediterranean fever? A systematic review

INTRODUCTION

Familial Mediterranean Fever (FMF) is the most common monogenic autoinflammatory disease characterized by recurrent fever and serosal inflammation. Although colchicine is the primary treatment, around 10% of FMF patients do not respond to it, necessitating alternative therapies. Biologic treatments, such as IL-1β, TNF-α and IL-6 inhibitors, have been considered. However, the accessibility and cost of IL-1β inhibitors may limit their use in certain regions. Tocilizumab (TCZ), an IL-6 receptor inhibitor, offers an alternative, but its efficacy in FMF is not well-documented.

OBJECTIVE

To evaluate the efficacy and safety of TCZ in the treatment of FMF.

METHODS

Following PRISMA guidelines, we identified 237 articles on the use of TCZ in FMF.

RESULTS

After selection, 14 articles were included: two double-blind RCTs, two retrospective studies and 10 case reports. Multicentre double-blind RCTs reported mixed results in FMF patients without AA amyloidosis due to genetic/classification heterogeneity of the available studies, possible misdiagnosed FMF patients and study design. Retrospective studies suggest that TCZ may benefit FMF patients with established renal AA amyloidosis, potentially preventing progression and managing flares more effectively. TCZ showed a safe profile with no specific adverse events, but data on its use during pregnancy or breastfeeding are lacking. There was no available data on the use of TCZ in paediatric FMF.

CONCLUSION

This review summarizes the current state of research, safety and efficacy of TCZ in FMF. While IL1β inhibitors remain the first choice for colchicine-resistant or intolerant FMF patients, TCZ might be of interest in some selected FMF patients with established AA amyloidosis and resistance to colchicine and interleukin 1 inhibitors.

Clinical Challenges of Emerging Acquired Autoinflammatory Diseases, Including VEXAS Syndrome

Vacuoles, E1-ubiquitin-activating enzyme, X-linked, autoinflammatory, somatic (VEXAS) syndrome, caused by an acquired mutation in the ubiquitin-activating enzyme ubiquitin-like modifier activating enzyme 1 (UBA1), was discovered in 2020. Since then, many cases have been reported worldwide. Recently, we performed UBA1 genetic testing in suspected cases of VEXAS throughout Japan and investigated the clinical features of these cases. Most cases were elderly patients in their 70s with clinical features consistent with VEXAS syndrome, such as myelodysplastic syndrome, high-grade fever, skin rash, chondritis, and pulmonary infiltration. However, approximately half of the analyzed patients were negative for the UBA1 variant. As the concept of "acquired autoinflammatory diseases," including VEXAS syndrome, has gained popularity, the number of suspected cases is expected to increase. Currently, there are no established diagnostic or treatment guidelines for these conditions, and they need to be urgently developed. This review summarizes the clinical problems faced by patients with acquired autoinflammatory diseases, including VEXAS.

Clinical, Immunologic, and Genetic Characteristics in Patients With Syndrome of Undifferentiated Recurrent Fevers

OBJECTIVE

Syndrome of undifferentiated recurrent fevers (SURF) is characterized by recurrent fevers and autoinflammation without a confirmed molecular diagnosis of a hereditary recurrent fever syndrome, and not fulfilling criteria for periodic fever, adenitis, pharyngitis, aphthous stomatitis syndrome (PFAPA). The goal of this study was to characterize clinical features of patients with SURF compared to patients with PFAPA and to analyze their cytokine signature, genetic variations, and responses to treatment.

METHODS

We enrolled 46 patients observed at Cincinnati Children's Hospital Medical Center. Baseline data and inflammatory cytokines were collected at enrollment, and their clinical course was followed. Cytokine analysis was performed using a cytokine multiplex assay. Many patients had specific or whole exome genetic testing.

RESULTS

The prevalence of rash and arthralgias were higher in patients with SURF compared to patients with PFAPA. Pharyngitis and adenopathy were less frequent. A subset of patients with SURF clustered together with elevated proinflammatory cytokines and more frequently required biologic therapy. Focused analysis of whole exome sequencing  data revealed that variants of unknown clinical significance (VUCS) were frequently identified in genes implicated in B cell development, immunodeficiencies, and inflammatory bowel disease risk. Treatments for patients with SURF commonly included on-demand steroids, colchicine, and anti-interleukin-1 therapy.

CONCLUSION

Our findings suggest SURF is a heterogeneous group but has distinct clinical and immunologic features from disorders such as PFAPA. Patients have frequent VUCS, which may have relevance to disease pathogenesis. A subset of patients showed more inflammation and an increased need for biologic therapy. Further research is necessary to define whether there exist distinct SURF endotypes and to better predict treatment outcomes.

Attempts to identify the molecular cause of autoinflammatory recurrent fever

Systemic autoinflammatory diseases caused by dysregulation of the innate immunity are a known cause of recurrent fevers. We present the molecular diagnosis results of 12 children with recurrent fever, analyzing the correlation between molecular findings and clinical symptoms. No pathogenic variants confirming autoinflammatory disease were found. One child was diagnosed with SRP54 deficiency, linked to congenital neutropenia with a cyclic pattern. Variants of uncertain significance were found in 6 patients in genes associated with autoinflammatory disorders, though two lacked clinical correlation. Variants of uncertain significance in the NLRC4 gene were detected in 2 patients with periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome, in the PLSG2 gene in 1 child with systemic juvenile idiopathic arthritis, and in the MEFV gene in 1 patient with syndrome of uncertain recurrent fever. COVID-19 was identified as a triggering factor in 54.5% of cases. Further research is needed to clarify the role of genetic variants and environmental factors in recurrent fevers.

Endoscopic characterization of gastrointestinal manifestations in children with undifferentiated recurrent fever

BACKGROUND AND STUDY AIMS

Systemic autoinflammatory diseases are characterized by recurrent or chronic inflammation, and monogenic forms are increasingly defined. However, a group of patients without genetic diagnosis is called the syndrome of undifferentiated recurrent fever (SURF). This study analyzed the clinical and endoscopic features of patients with SURF presenting with gastrointestinal (GI) symptoms.

PATIENTS AND METHODS

Between 2019 and 2022, GI endoscopy were performed in patients with SURF who presented with GI symptoms. Clinical, genetic, laboratory, and endoscopy findings were analyzed.

RESULTS

Fifteen patients were included in the study, eight (53.3 %) were girls. The mean age was 10.5 ± 5.80 years, and the median age at symptom onset was 4 (0.3-16) years. All patients experienced fever and abdominal pain. Thirteen patients (86.7 %) experienced diarrhea, 11 (73.3 %) reported myalgia, and 10 (66.7 %) had joint involvement. Lymphoid follicles in the terminal ileum mucosa were detected in 10 patients (66.7 %), and nodular lymphoid hyperplasia in the terminal ileum was the histopathological finding in 12 patients (80 %).

CONCLUSIONS

The current study found that patients with SURF experiencing gastrointestinal symptoms have excessive lymph node formation in the terminal ileal mucosa due to an exaggerated inflammatory response. This may be the cause of their GI symptoms.

TNFRSF11A variants contribute to systemic autoinflammatory diseases: A case series of 12 patients

BACKGROUND

Limited evidence suggests that variants in TNFRSF11A gene, encoding RANK, may contribute to systemic autoinflammatory disease (SAID).

AIM/METHODS

To estimate the prevalence of TNFRSF11A variants in a cohort of patients with SAIDs screened for 26 related genes and describe the disease phenotypic expression.

RESULTS

A total of 12 out of 167 patients, 7 males, aged (median) 38 years at disease onset, yielded at least one TNFRSF11A rare variant. All patients carried a coexisting variant in at least one other SAID-related gene, most frequently MEFV (6 patients), but also TNFRSF1A, NOD2, NLRP3, NLRP7, MVK, IL36RN, RBCK1, PLCG2 and PSMB8. SAID episodes lasting (median) 9 days manifested with high grade fever (91%), myalgias (75%), malaise (67%), serositis (58%), arthralgias/arthritis (58%), gastrointestinal involvement (33%), and rash (25%), and responded to corticosteroids. The most common initial clinical diagnosis was TNF-associated periodic fever syndrome (TRAPS), which was, however, confirmed, in only one patient. The emergence of MEFV variations supported the diagnosis of atypical Familial Mediterranean Fever in two cases, whereas the diagnosis of Yao syndrome was speculated in two patients with NOD2 variants. The presence of atypical disease and the inability of defining diagnosis in the remaining 7 patients, supported the possible involvement of TNFRSF11A variants in the phenotypic expression of SAIDs.

CONCLUSION

TNFRSF11A variants, occurring in 7% of SAID patients always in combination with other SAID-related gene variants, contribute to the development of an autoinflammatory syndrome resembling to TRAPS. Additional studies to confirm novel pathogenic SAID pathways are clearly warranted.

Otorhinolaryngological manifestations of autoinflammatory diseases. Systematic review

OBJECTIVES

To detail the main otorhinolaryngological manifestations of autoinflammatory diseases, aiming to contribute to early diagnosis and treatment.

DATA SOURCES

Searches were conducted in PubMed, LILACS, Cochrane Library.

REVIEW METHODS

A systematic review of the medical literature on autoinflammatory diseases was conducted to identify characteristic head and neck manifestations, using PRISMA criteria. Observational studies or systematic reviews with a minimum of 10 cases per disease were included. Qualitative synthesis and a risk assessment were carried out.

RESULTS

Our review included 29 articles that met the inclusion criteria, with 10 to 486 patients per study. Autoinflammatory diseases with characteristic head and neck manifestations included VEXAS syndrome (auricular, nasal, or laryngotracheal chondritis), NPRL3-AID (hearing loss), NPRL12-AID (cervical lymphadenopathies, hearing loss and oral ulcers), HIDSs syndrome (painful cervical nodes and oral ulcers), haploinsufficiency A20 (oral ulcers), TRAPS (pharyngitis, aphthous stomatitis, periorbital edema, and cervical lymphadenopathies), Behcet's disease (oral and pharyngeal ulcers), PFAPA syndrome (recurrent tonsillitis, oral ulcers, and painful cervical adenopathies), Kawasaki disease (cervical nodes, pharyngitis and changes in oral mucosa) and undefined periodic fever (pharyngitis, oral ulcers, and painful cervical nodes).

CONCLUSION

Given their complex diagnosis and unique head and neck manifestations, otolaryngologists must be well-versed in these diseases for early detection and treatment. ENT specialists should consider the possibility of an autoinflammatory disease when encountering symptoms such as auricular, nasal, or laryngeal chondritis, recurrent oral ulcers, painful inflammatory lymphadenopathies, periorbital edema, recurrent pharyngitis, or hearing loss within the context of compatible systemic conditions.

Impact of multiple MEFV variants of unknown significance on the diagnosis and clinical presentation of familial Mediterranean fever

The detection of variants of unknown significance (VUS) in familial Mediterranean fever (FMF) is common; however, their diagnostic value remains elusive, and the interpretation of multiple VUS remains difficult. Therefore, we examined FMF diagnosis-associated factors 1-year post-genetic testing in patients with only VUS and assessed the impact of multiple VUS on diagnosis and clinical features. A 1-year follow-up was conducted on patients clinically suspected of having FMF without confirmatory diagnosis owing to the presence of only VUS. Clinical features were compared between patients with a single VUS and those with multiple VUS among patients diagnosed with FMF. Among 261 patients followed up, 202 were diagnosed with FMF based on clinical judgment. No specific clinical symptoms or variant patterns at genetic testing were associated with diagnosis at 1 year. Multiple VUS was significantly and independently associated with a lower response to colchicine than single VUS among patients diagnosed with FMF. However, clinical symptoms showed no correlation with the number of VUS. In conclusion, predicting FMF diagnosis 1-year post-genetic testing in patients with only VUS remains challenging. Moreover, the impact of multiple VUS on FMF may be limited owing to the lack of correlation with clinical features, except colchicine response.

Autoinflammatory Diseases: A Review

Autoinflammatory disease (AID) is a vast spectrum of disorders characterized by recurrent attacks of sterile inflammation. Since the first cloning of the familial Mediterranean fever gene in 1997, there has been a rapid rate of discovery of new AIDs. As of 2022, there have been 485 inborn errors of immunity documented by the International Union of Immunological Societies, for which many display aspects of autoinflammation. The pathophysiology of AIDs is complex. Although many are caused by rare mutations in genes that govern innate immunity, others are polygenic, where disease expression is thought to be triggered by environmental factors in genetically predisposed hosts. AIDs range in prevalence from common entities like gout to ultrarare monogenic diseases. Whereas AIDs were initially studied in pediatric populations, it is now apparent that they can present in adulthood and even in the elderly. AIDs can be clinically challenging given their rarity, as well as the heterogeneity in presentation and underlying etiology. Although the care of AIDs can span medical disciplines, the rheumatologist often plays a central role given the inflammatory nature of these illnesses. In this review, we explore the current understanding of the pathophysiology of these complex conditions and propose a classification system for AIDs. We place an emphasis on AIDs that present to the adult rheumatologist and discuss important AIDs that can mimic more classic rheumatic diseases such as systemic lupus erythematosus and inflammatory arthritis. Finally, we offer an approach to the clinical assessment, diagnosis, and management of AIDs.

New and future perspectives in familial Mediterranean fever and other autoinflammatory diseases

Systemic autoinflammatory diseases are a group of disorders characterized by sterile episodes of inflammation resulting from defects in the innate immune system. In contrast to classical autoimmune diseases, where circulating autoantibodies and the adaptive immune system are involved, these conditions involve excessive presence of proinflammatory cytokines leading to inflammatory attacks. Excessive cytokine production, functional mutations in regulatory pathways, excessive interferon production, defects in the nuclear factor-kappa B signaling pathway, abnorARCHmal protein folding, and complement activation are the mechanisms leading to autoinflammatory diseases. A defect in the mTOR pathway and trained immunity are newly discovered possible causes in pathogenesis. Early onset and severe forms of classical rheumatological diseases have been more frequently associated with autoinflammatory diseases in the last decade. Therefore, monogenic autoinflammatory diseases should be considered in rheumatic diseases with family history, consanguinity, early onset, and severe disease. The combination of functional and genotyping research will help to identify unclassified patients. The optimal treatment strategy remains uncertain, functional studies such as interferon signature and cytokine profiling, may prove valuable in guiding the treatment process. Stem cell transplantation strategies in autoinflammatory diseases with partial response to biological therapies can be considered. Autoinflammatory diseases are becoming increasingly complex and are bringing new perspectives to already known rheumatic diseases. Although we have effective treatments, we are still far from personalized recommendations.

A Challenging Case of Recurrent Fever

Syndrome of undifferentiated recurrent fever (SURF) includes heterogeneous episodes of systemic inflammation without documented infection, without response to antibiotherapy, and characterized by a paucity of specific clinical or molecular criteria. Colchicine is an effective treatment with an impact on morbimortality. We describe a case of a previously healthy one-year-old male, with consanguineous ancestry, admitted four times due to recurrent fever, associated with nonspecific symptoms and an increase of inflammatory markers in a sepsis-like pattern. No consistent infection was documented, and there was no response to broad-spectrum antibiotics. The evolution revealed corticosteroid dependency. The autoinflammatory syndrome-targeted next-generation sequencing (NGS) gene panel didn't detect relevant pathogenic variants. SURF was postulated as a diagnosis of exclusion, and the effectiveness of colchicine supports an autoinflammatory etiology. We aimed to draw attention to recurrent fevers associated with autoinflammatory disorders due to their challenging diagnosis. Improved understanding of immune pathways and advances in genetic testing will enable greater accuracy in the approach.

Disease phenotypes in adult patients with suspected undifferentiated autoinflammatory diseases and PFAPA syndrome: Clinical and therapeutic implications

BACKGROUND

Undifferentiated autoinflammatory diseases are characterized by recurrent or persistent fever, usually combined with other inflammatory manifestations, and negative or inconclusive genetic studies for monogenic autoinflammatory disorders.

AIMS

To define and characterize disease phenotypes in adult patients diagnosed in an adult reference center with undifferentiated autoinflammatory diseases, and to analyze the efficacy of the drugs used in order to provide practical diagnostic and therapeutic recommendations.

METHODS

Retrospective study (2015-2022) of patients with undifferentiated autoinflammatory diseases among all patients visited in our reference center. Demographic, clinical, laboratory features and detailed therapeutic information was collected.

RESULTS

Of the 334 patients with a suspected autoinflammatory disease, 134 (40%) patients (61% women) were initially diagnosed with undifferentiated autoinflammatory diseases. Mean age at disease onset and at diagnosis was 28.7 and 37.7 years, respectively. In 90 (67.2%) patients, symptoms started during adulthood. Forty-four (32.8%) patients met diagnostic/classification criteria for adult periodic fever with aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome. In the remaining patients, four additional phenotypes were differentiated according to the predominant manifestations: a) Predominantly fever phenotype (n = 18; 13.4%); b) Predominantly abdominal/pleuritic pain phenotype (n = 9; 6.7%); c) Predominantly pericarditis phenotype (n = 18; 13.4%), and d) Complex syndrome phenotype (n = 45; 33.6%). Prednisone (mainly on demand), colchicine and anakinra were the drugs commonly used. Overall, complete responses were achieved with prednisone in 41.3%, colchicine in 40.2%, and anakinra in 58.3% of patients in whom they were used. By phenotypes, prednisone on demand was more effective in adult PFAPA syndrome and colchicine in patients with the abdominal/pleuritic pain pattern and PFAPA syndrome. Patients with complex syndrome achieved complete responses with prednisone (21.9%), colchicine (25.7%) and anakinra (44.4%), and were the group more often requiring additional immunosuppressive drugs.

CONCLUSIONS

The analysis of the largest single-center series of adult patients with undifferentiated autoinflammatory diseases identified and characterized different disease phenotypes and their therapeutic approaches. This study is expected to contribute to increase the awareness of physicians for an early identification of these conditions, and to provide the best known therapeutic options.

Clinical presentation and genetic variants in patients with autoinflammatory diseases: results from the German GARROD registry

To investigate clinical symptoms and genetic variants in patients from the German anti-IL-1 registry for autoinflammatory orphan diseases (GARROD) between 2013 and 2022. Multicentre, retrospective analysis of demographic, clinical and genetic data of patients with autoinflammatory diseases (AID) who received anti-IL-1 targeted therapy. The cohort comprised 152 patients with familial Mediterranean fever (FMF; n = 71), cryopyrin-associated periodic syndromes (CAPS; n = 43), TNF-receptor associated periodic syndrome (TRAPS; n = 19), mevalonate kinase deficiency (MKD; n = 3) and unclassified AID (uAID; n = 16). Inflammatory attacks started in 61.2% of the patients before the age of 18 years. The delay between the first AID attack and anti-IL-1 therapy was 17.8 years. Monogenetic AIDs were diagnosed by clinical symptoms. Genetic analyses confirmed the diagnosis in 87.3% of patients with FMF, 65.2% with CAPS and 94.8% with TRAPS. Among this group, heterozygous MEFV variants and variants of unknown significance (VUS) were detected in 22.5% of patients with FMF, 51.2% with CAPS and 47.4% with TRAPS. Patients with VUS were older at disease onset which is consistent with a milder phenotype. Twenty-four patients had secondary AA amyloidosis (AA) at initiation of anti-IL-1 therapy. The mean age of these patients was 16.4 years at their first attack and 44.9 years at the time of AA diagnosis. Turkish-Armenian ancestry correlated with MEFV variants and higher FMF disease activity compared to German ancestry. Molecular genetic analyses should substantiate the clinical diagnosis of a monogenetic AID. Our data support the concept of variable penetrance of VUS which can be associated with late-onset AID.

The expanding clinical spectrum of autoinflammatory diseases with NOD2 variants: a case series and literature review

Objective

To assess the impact conferred by NOD2 variants on the clinical spectrum of patients with systemic autoinflammatory diseases (SAIDs) in Greece.

Methods

Consecutive patients (n=167) with confirmed SAIDs who underwent screening by next generation sequencing (NGS) targeting 26 SAID-associated genes, and carried at least one NOD2 gene variant, were retrospectively studied. The demographic, clinical and laboratory parameters were recorded.

Results

In total, 24 rare NOD2 variants in 23/167 patients (14%) were detected. Notably, 18 patients had at least one co-existing variant in 13 genes other than NOD2. Nine patients had juvenile- and 14 adult-onset disease. All patients presented with symptoms potentially induced by the NOD2 variants. In particular, the candidate clinical diagnosis was Yao syndrome (YAOS) in 12 patients (7% of the whole SAID cohort). The clinical spectrum of patients with YAOS (mean episode duration 8 days) was fever (n=12/12), articular symptoms (n=8), gastrointestinal symptoms (n=7; abdominal pain/bloating in 7; diarrhea in 4; oral ulcers in 3), serositis (n=7), and rash (n=5), while the inflammatory markers were elevated in all but one patient. Most of these patients showed a poor response to nonsteroidal anti-inflammatory drugs (n=7/9), colchicine (n=6/8) and/or anti-TNF treatment (n=3/4), while a complete response was observed in 6/10 patients receiving steroids and 3/5 on anti-IL1 treatment. Another 8 patients were diagnosed with either FMF (n=6) or PFAPA syndrome (n=2) presenting with prominent diarrhea (n=7), oral ulcers (n=2), periorbital swelling and sicca-like symptoms (n=1), or maculopapular rash (n=1). One patient had a clinically undefined SAID, albeit characterized by oral ulcers and diarrhea. Finally, one patient presented with chronic relapsing urticaria with periorbital edema and inflammatory markers, and another one had a Crohn-like syndrome with good response to anti-IL-1 but refractory to anti-TNF treatment.

Conclusion

NOD2 variants were detected in 1 out of 7 SAID patients and seem to have an impact on disease phenotype and treatment response. Further studies should validate combined molecular and clinical data to better understand these distinct nosological entities.

Pyrin Inflammasome Activation Defines Colchicine-Responsive SURF Patients from FMF and Other Recurrent Fevers

Syndrome of undifferentiated recurrent fever (SURF) is characterized by recurrent fevers, a lack of confirmed molecular diagnosis, and a complete or partial response to colchicine. Despite the clinical similarities to familial Mediterranean fever (FMF), the underlying inflammatory mechanisms of SURF are not yet understood. We here analyzed the in vitro activation of the pyrin inflammasome in a cohort of SURF patients compared to FMF and PFAPA patients. Peripheral blood mononuclear cells (PBMC) were collected from SURF (both colchicine-treated and untreated), FMF, PFAPA patients, and healthy donors. PBMC were stimulated ex vivo with Clostridium difficile toxin A (TcdA) and a PKC inhibitor (UCN-01), in the presence or absence of colchicine. The assembly of the pyrin inflammasome was evaluated by measuring the presence of apoptosis-associated Speck-like protein containing caspase recruitment domain (ASC) specks in monocytes using flow cytometry. IL-1β secretion was quantified using an ELISA assay. No differences in TcdA-induced activation of pyrin inflammasome were observed among FMF, PFAPA, and healthy donors. Untreated SURF patients showed a reduced response to TcdA, which was normalized after colchicine treatment. In contrast to FMF, SURF patients, similar to PFAPA patients and healthy donors, did not exhibit pyrin inflammasome activation in response to UCN-01-mediated pyrin dephosphorylation. These data demonstrate that in vitro functional analysis of pyrin inflammasome activation can differentiate SURF from FMF and PFAPA patients, suggesting the involvement of the pyrin inflammasome in the pathophysiology of SURF.

Safety and efficacy of canakinumab treatment for undifferentiated autoinflammatory diseases: the data of a retrospective cohort two-centered study

Introduction

The blockade of interleukine-1 (anakinra and canakinumab) is a well-known highly effective tool for monogenic autoinflammatory diseases (AIDs), such as familial Mediterranean fever, tumor necrosis factor receptor-associated periodic syndrome, hyperimmunoglobulinaemia D syndrome, and cryopyrin-associated periodic syndrome, but this treatment has not been assessed for patients with undifferentiated AIDs (uAIDs). Our study aimed to assess the safety and efficacy of canakinumab for patients with uAIDs.

Methods

Information on 32 patients with uAIDs was retrospectively collected and analyzed. Next-generation sequencing and Federici criteria were used for the exclusion of the known monogenic AID.

Results

The median age of the first episode was 2.5 years (IQR: 1.3; 5.5), that of the disease diagnosis was 5.7 years (IQR: 2.5;12.7), and that of diagnostic delay was 1.1 years (IQR: 0.4; 6.1). Patients had variations in the following genes: IL10, NLRP12, STAT2, C8B, LPIN2, NLRC4, PSMB8, PRF1, CARD14, IFIH1, LYST, NFAT5, PLCG2, COPA, IL23R, STXBP2, IL36RN, JAK1, DDX58, LACC1, LRBA, TNFRSF11A, PTHR1, STAT4, TNFRSF1B, TNFAIP3, TREX1, and SLC7A7. The main clinical features were fever (100%), rash (91%; maculopapular predominantly), joint involvement (72%), splenomegaly (66%), hepatomegaly (59%), lymphadenopathy (50%), myalgia (28%), heart involvement (31%), intestinal involvement (19%); eye involvement (9%), pleuritis (16%), ascites (6%), deafness, hydrocephalia (3%), and failure to thrive (25%). Initial treatment before canakinumab consisted of non-biologic therapies: non-steroidal anti-inflammatory drugs (NSAID) (91%), corticosteroids (88%), methotrexate (38%), intravenous immunoglobulin (IVIG) (34%), cyclosporine A (25%), colchicine (6%) cyclophosphamide (6%), sulfasalazine (3%), mycophenolate mofetil (3%), hydroxychloroquine (3%), and biologic drugs: tocilizumab (62%), sarilumab, etanercept, adalimumab, rituximab, and infliximab (all 3%). Canakinumab induced complete remission in 27 patients (84%) and partial remission in one patient (3%). Two patients (6%) were primary non-responders, and two patients (6%) further developed secondary inefficacy. All patients with partial efficacy or inefficacy were switched to tocilizumab (n = 4) and sarilumab (n = 1). The total duration of canakinumab treatment was 3.6 (0.1; 8.7) years. During the study, there were no reported Serious Adverse Events (SAEs). The patients experienced non-frequent mild respiratory infections at a rate that is similar as before canakinumab is administered. Additionally, one patient developed leucopenia, but it was not necessary to stop canakinumab for this patient.

Conclusion

The treatment of patients with uAIDs using canakinumab was safe and effective. Further randomized clinical trials are required to confirm the efficacy and safety.

A "SURFin' Leukemia": Acute Lymphoblastic Leukemia Masquerading as a Syndrome of Undifferentiated Recurrent Fever

Periodic fever is not uncommon in childhood and is often ascribed to autoinflammatory conditions; however, it may be present also in children with cancer. We here describe the case of a 3-year-old boy with acute lymphoblastic leukemia who initially presented with a 4-month history of recurrent, stereotyped episodes of fever and localized joint pain, separated by completely symptom-free intervals. These symptoms were initially interpreted as a possible syndrome of undifferentiated recurrent fever until more signs of leukemia became apparent. Our report confirms that acute lymphoblastic leukemia can rarely present with periodic fever, thus possibly leading to diagnostic errors unless a high index of suspicion is maintained.

Detection of a rare variant in PSTPIP1 through three generations in a family with an initial diagnosis of FMF/MKD-overlapping phenotype

OBJECTIVE

The presence of FMF cases without MEFV (MEFV innate immunity regulator, pyrin) pathogenic variants led us to search for other genes' involvement in the disease development. Here, we describe the presence of genetic heterogeneity in a three-generation family with an FMF/mevalonate kinase deficiency (MKD)-overlapping phenotype without MEFV/MVK (mevalonate kinase) pathogenic variants.

METHOD

Targeted sequencing revealed a rare, fully penetrant variant in PSTPIP1 (p.Arg228Cys, rs781341816). Computational stability analyses of PSTPIP1 protein were performed. PSTPIP1-pyrin protein interaction was examined by immunoprecipitation and immunoblotting in peripheral blood mononuclear cells (PBMCs) of patients and healthy controls. PBMCs were cultured, and inflammation was induced by LPS+ATP treatment, followed by protein level measurements of caspase-1, IL1ß, pyrin and PSTPIP1 in cell lysates and mature caspase-1 and mature IL1ß in supernatants.

RESULTS

The conserved, rare (GnomAD, 0.000028) PSTPIP1 p.Arg228Cys variant, previously reported in ClinVar as a variant with uncertain significance, showed complete penetrance in the family presenting an autosomal dominant pattern. Computational analyses showed a potentially destabilizing effect of the variant on PSTPIP1 protein. Accordingly, PSTPIP1-pyrin interaction was increased in patients harboring the variant, which resulted in elevated levels of mature caspase-1 and IL1ß in the inflammation-induced patient samples.

CONCLUSIONS

Unlike previously described cases with pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA)-associated PSTPIP1 variants, our patients with the p.Arg228Cys variant presented with an FMF/MKD-overlapping phenotype. As additional data on the genetic heterogeneity in the variable clinical spectrum of autoinflammatory syndromes, we suggest that the p.Arg228Cys variant in PSTPIP1 is related to inflammation responses through strong PSTPIP1-pyrin interaction and pyrin inflammasome activation.

Identification by Exome Sequencing of Predisposing Variants in Familial Cases of Autoinflammatory Recurrent Fevers

Periodic fever syndromes include autoinflammatory disorders (AID) that involve innate immunity. These disorders are characterized by recurrent fevers and aberrant multi-organ inflammation, without any involvement of T or B cells or the presence of autoantibodies. A complex genetic architecture has been recognized for many AID. However, this complexity has only been partially uncovered for familial Mediterranean fever and other conditions that have a classical monogenic origin and Mendelian transmission. Several gene panels are currently available for molecular diagnosis in patients suspected of having AID. However, even when an extensive number of genes (up to 50-100) are tested in a cohort of clinically selected patients, the diagnostic yield of AID ranges between 15% and 25%, depending on the clinical criteria used for patient selection. In the remaining 75-85% of cases, it is conceivable that the causative gene or genes responsible for a specific condition are still elusive. In these cases, the disease could be explained by variants, either recessive or dominant, that have a major effect on unknown genes, or by the cumulative impact of different variants in more than one gene, each with minor additive effects. In this study, we focused our attention on five familial cases of AID presenting with classical autosomal dominant transmission. To identify the probable monogenic cause, we performed exome sequencing. Through prioritization, filtering, and segregation analysis, we identified a few variants for each family. Subsequent bioinformatics evaluation and pathway analysis helped to narrow down the best candidate genes for each family to FCRL6, PKN1, STAB1, PTDGR, and VCAM1. Future studies on larger cohorts of familial cases will help confirm the pathogenic role of these genes in the pathogenesis of these complex disorders.

The assessment of autoinflammatory disease classification criteria (Eurofever/PRINTO) in a real-life cohort

OBJECTIVE

The aim of the study was to determine the sensitivity and specificity rates of Eurofever/PRINTO autoinflammatory recurrent fever classification criteria with real-life data in patients with an autoinflammatory disease.

METHODS

A total of 119 patients were included in the study. Based on clinical symptoms, they were divided into four subgroups: cryopyrin-associated periodic syndromes (CAPS), TNF receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), and syndrome of undifferentiated recurrent fever (SURF) using the Eurofever/PRINTO clinical classification criteria. In the last step, the patients were re-evaluated in the light of genetic results and their final diagnosis was reached.

RESULTS

A total of 119 patients, including 37 CAPS, 13 TRAPS, 8 MKD, 39 SURF, 14 NLRP12-related autoinflammatory disease (NLRP12-AID), and 8 familial Mediterranean fever (FMF) patients were evaluated in the study. While the sensitivity of the new clinical Eurofever/PRINTO criteria was 48% for CAPS, 77% for TRAPS, 87.5%for MKD, and the specificity of the clinical criteria was 86% for CAPS, 85% for TRAPS, and 60% for MKD. The sensitivity of the new mixed (genetic plus clinical variables) Eurofever/PRINTO criteria was 27% for CAPS, 61% forTRAPS, 85% for MKD, and the specificity of the mixed criteria for each group was 100%.

CONCLUSION

We found the sensitivity of the Eurofever/PRINTO classification criteria to be low as genotypic changes between populations cause phenotypic differences. For this reason, we think that patient-based evaluation is correct rather than standard classification criteria in real life. Key-points • In systemic autoinflammatory diseases, common variants in the populations may alter the phenotype, and making it difficult to classify some patients with the current classification criteria. • In populations with common genetic variants, the classification criteria should be modified according to the clinical phenotype.

IL-1 and autoinflammatory disease: biology, pathogenesis and therapeutic targeting

Over 20 years ago, it was first proposed that autoinflammation underpins a handful of rare monogenic disorders characterized by recurrent fever and systemic inflammation. The subsequent identification of novel, causative genes directly led to a better understanding of how the innate immune system is regulated under normal conditions, as well as its dysregulation associated with pathogenic mutations. Early on, IL-1 emerged as a central mediator for these diseases, based on data derived from patient cells, mutant mouse models and definitive clinical responses to IL-1 targeted therapy. Since that time, our understanding of the mechanisms of autoinflammation has expanded beyond IL-1 to additional innate immune processes. However, the number and complexity of IL-1-mediated autoinflammatory diseases has also multiplied to include additional monogenic syndromes with expanded genotypes and phenotypes, as well as more common polygenic disorders seen frequently by the practising clinician. In order to increase physician awareness and update rheumatologists who are likely to encounter these patients, this review discusses the general pathophysiological concepts of IL-1-mediated autoinflammation, the epidemiological and clinical features of specific diseases, diagnostic challenges and approaches, and current and future perspectives for therapy.

Development and Implementation of the AIDA International Registry for Patients With Undifferentiated Systemic AutoInflammatory Diseases

Objective

This paper points out the design, development and deployment of the AutoInflammatory Disease Alliance (AIDA) International Registry dedicated to pediatric and adult patients affected by Undifferentiated Systemic AutoInflammatory Diseases (USAIDs).

Methods

This is an electronic registry employed for real-world data collection about demographics, clinical, laboratory, instrumental and socioeconomic data of USAIDs patients. Data recruitment, based on the Research Electronic Data Capture (REDCap) tool, is designed to obtain standardized information for real-life research. The instrument is endowed with flexibility, and it could change over time according to the scientific acquisitions and potentially communicate with other similar tools; this platform ensures security, data quality and data governance.

Results

The focus of the AIDA project is connecting physicians and researchers from all over the world to shed a new light on heterogeneous rare diseases. Since its birth, 110 centers from 23 countries and 4 continents have joined the AIDA project. Fifty-four centers have already obtained the approval from their local Ethics Committees. Currently, the platform counts 290 users (111 Principal Investigators, 179 Site Investigators, 2 Lead Investigators, and 2 data managers). The Registry is collecting baseline and follow-up data using 3,769 fields organized into 23 instruments, which include demographics, history, symptoms, trigger/risk factors, therapies, and healthcare information access for USAIDs patients.

Conclusions

The development of the AIDA International Registry for USAIDs patients will facilitate the online collection of real standardized data, connecting a worldwide group of researchers: the Registry constitutes an international multicentre observational groundwork aimed at increasing the patient cohort of USAIDs in order to improve our knowledge of this peculiar cluster of autoinflammatory diseases. NCT05200715 available at https://clinicaltrials.gov/.

COVID-19 infection among patients with autoinflammatory diseases: a study on 117 French patients compared with 1545 from the French RMD COVID-19 cohort: COVIMAI - the French cohort study of SARS-CoV-2 infection in patient with systemic autoinflammatory diseases

Objective

There is little known about SARS-CoV-2 infection in patients with systemic autoinflammatory disease (SAID). This study aimed to describe epidemiological features associated with severe disease form and death. Mortality between patients with and without SAID hospitalised for SARS-CoV-2 infection was compared.

Methods

A national multicentric prospective cohort study was conducted from the French Rheumatic and Musculoskeletal Diseases (RMD) COVID-19 cohort. Patients with SAID were matched with patients with non-SAID on age±7 years, gender and number of comorbidities to consider important confounding factors. Impact of SAID on severity of SARS-CoV-2 infection was analysed using multinomial logistic regression for severity in three classes (mild, moderate and severe with mild status as reference). Fine-Gray regression model for length of hospital stay and binomial logistic regression model for risk of death at 30 days.

Results

We identified 117 patients with SAID (sex ratio 0.84, 17 children) and compared them with 1545 patients with non-autoinflammatory immune-mediated inflammatory disorders (non-SAID). 67 patients had a monogenic SAID (64 with familial Mediterranean fever). Other SAIDs were Behçet’ disease (n=21), undifferentiated SAID (n=16), adult-onset Still disease (n=9) and systemic-onset juvenile idiopathic arthritis (n=5). Ten adults developed severe form (8.6%). Six patients died. All children had a benign disease. After matching on age±7 years, sex and number of comorbidities, no significant difference between the two groups in length of stay and the severity of infection was noted.

Conclusion

As identified in the whole French RMD COVID-19 cohort, patients with SAID on corticosteroids and with multiple comorbidities are prone to develop more severe COVID-19 forms.

Clinical characterization, long-term follow-up, and response to treatment of patients with syndrome of undifferentiated recurrent fever (SURF)

OBJECTIVES

To describe a homogeneous group of patients with undifferentiated recurrent fevers followed-up in a tertiary referral center for systemic autoinflammatory diseases (SAIDs).

METHODS

Patients with undifferentiated recurrent fevers seen at our Center from 2008 to 2021 and followed-up for at least one year were included in a retrospective study. Monogenic recurrent fevers, patients carrying variants of unknown origin and PFAPA (Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis) syndrome were excluded.

RESULTS

Fifty patients (34 male, 16 female) were included in the study. The median age at onset was 3 years, and the median follow-up was 3.3 years. At baseline, arthralgia (70%) and abdominal pain (65%) were the most frequent manifestations. NSAIDs or steroids on demand had a variable and transient effect. Tonsillectomy was ineffective in the 10 patients (20%) that underwent surgery. Forty-eight patients (96%) were treated with colchicine. A complete response (absence of fever) was achieved in 31 patients (64.6%). Nine patients (18%) showed a partial response, with a median reduction of fever episodes per year of 72%. Nine patients (16.7%) were considered resistant to colchicine. The presence of generalized lymphadenopathy and, to a lesser extent, exudative tonsillitis was associated with a lack of response to colchicine.

CONCLUSIONS

We describe the largest series of patients with syndrome of undifferentiated recurrent fever (SURF) reported in the literature so far. SURF should be considered as a distinct clinical entity in the context of multifactorial autoinflammatory diseases.

Transitional care management in patients with auto-inflammatory diseases: experience of cooperation of a paediatric and adult centre

Objectives

Auto-inflammatory Diseases (AIDs) are a group of diseases with a strong genetic component, inducing an inappropriate activation of innate immunity. The patients with pediatric onset will face the transitional care (TC) from a pediatrician to an adult care setting, during the critical phase of the adolescence. That implies a risk of failure and drop out, due to the different approach of pediatrician compared to the adult doctor. To describe the model of TC for AIDs from a paediatric to adult centre of two hospitals in Rome, and to pointing out the different steps emerged from specific experiences.

Methods

In November 2020, a Board of paediatricians and internists discussed their experience to identify “hot topics” for a successful management of TC.

Results

The Board agreed on the optimal time for the transition (12–18 years). Specific elements to be considered are the reached level of emotional and intellectual maturity, and the clinical stability of the disease.

Conclusions

The TC of patients with chronic AIDs, requires a strong cooperation to define the adequate follow-up, and to guarantee the compliance to the treatment. This model allows us to investigate AIDs complex cases, requiring a long period of observations.

Anakinra in Paediatric Rheumatology and Periodic Fever Clinics: Is the Higher Dose Safe?

OBJECTIVE

Anakinra has been increasingly used in off-label indications as well as dosing and mode of administration in a variety of inflammatory conditions. We aimed to review our clinical practice and compare treatment outcomes with published data.

METHODS

Clinical data from electronic records were retrospectively reviewed for patients treated with anakinra over the past 6 years for autoinflammatory diseases (AID).

RESULTS

From 47 eligible patients (27 female patients), 32 were children. Macrophage activation syndrome (MAS) was the indication for anakinra therapy in 42.6% of patients. Systemic juvenile idiopathic arthritis (SJIA) was the most common underlying diagnosis (19/47) followed by the spectrum of AID. Off-label use was noted in 38.3% patients. Recommended dose was exceeded in 21 children (mean induction dose 5.1, highest dose 29.4 mg/kg/day) and two adults; five patients were treated intravenously. The mean treatment duration for SJIA was 1.4 years, that for AID was 2.2 years, and that for patients with higher anakinra dose was 9.7 (19.3) months. The mean follow-up duration was 2.7 (1.7) years. Treatment was effective in the majority of SJIA and cryopyrinopathy patients as well as those with MAS. Anakinra was well-tolerated without any major adverse effects even in patients with long-term administration of higher than recommended doses including two infants treated with a dose of over 20 mg/kg/day.

CONCLUSION

Our results support early use of anakinra in the individually tailored dosing. In patients with hyperinflammation, anakinra may be lifesaving and may even allow for corticosteroid avoidance. Further studies are needed in order to set up generally accepted response parameters and define condition-specific optimal dosing regimen.