New workflow for classification of genetic variants' pathogenicity applied to hereditary recurrent fevers by the International Study Group for Systemic Autoinflammatory Diseases (INSAID)

Long-term efficacy and safety of colchicine and anti-IL-1 blockers in FMF: results from the Eurofever multicenter observational study

INTRODUCTION

The majority of currently available data on familial Mediterranean fever (FMF) come from retrospective national or international studies.

METHODS

An observational study collected data on the Eurofever international FMF cohort. Patients fulfilling genetic and clinical Eurofever criteria were considered as FMF+. Patients not fulfilling clinical and/or genetic (one VUS or benign variants or negative for MEFV variants) criteria were considered as FMF-. Data on compliance to treatment and quality of life were also recorded.

RESULTS

Since November 2024, 876 FMF patients (466 M, 410 F) were enrolled, with a mean follow-up of 2.9 ± 3.1 years. 730 (84 %) patients were classified as FMF+, 146 (16 %) as FMF-, with significant differences in the prevalence of clinical manifestations and treatment response between the two groups. At the last follow-up, 433 patients (50.6 %) still had some disease activity. At the last follow-up 749 (85.5 %) patients received colchicine with a relative under dosage of the drug. Anti-IL-1 treatment was reported in 133 patients (15.2 %), mostly canakinumab (117, 13.4 %). Treatment compliance was generally satisfactory, and adverse events were generally mild.

CONCLUSIONS

Patients with an FMF-like phenotype who lack genetic confirmation display significant differences in clinical features and duration of attacks and show a less response to treatment during their disease course in respect, and thus, should be considered as FMF-mimics and investigated for other causes. Longitudinal data provides a more detailed comprehension of the long-term burden of FMF and the impact of treatment on disease activity and patients' quality of life.

The enigma of familial Mediterranean fever: phenotypic characterization of patients harbouring variants of uncertain significance

OBJECTIVE

To assess the phenotypic characteristics of the patients carrying variants of uncertain significance (VUS) in the Mediterranean fever (MEFV) gene.

METHODS

The study included patients carrying only VUS in the MEFV gene. Patients were excluded if they did not meet the paediatric criteria for familial Mediterranean fever (FMF). Patients were assigned to homozygous, compound heterozygous or heterozygous groups according to their genotype. Additionally, analyses were conducted based on specific genotypes.

RESULTS

A total of 2326 MEFV gene records were reviewed. Of these, 310 (F: 152/M: 158) met the inclusion criteria for analysis. The mean age at diagnosis and symptom onset was 7.51 ± 3.9 and 6.03 ± 3.86 years, respectively. Among the patients, 75.5% had a single variant, 17.1% were compound heterozygous, and 7.4% were homozygous. The common VUS alleles accounted for 93% of the cohort: E148Q (65.7%), P369S (15.6%), R408Q (7.6%) and A744S (4.1%). Most cases exhibited mild disease severity, while those with multiple variants were more likely to experience moderate disease severity. Patients with a homozygous allele had a higher mean number of annual attacks (11.2/year), a higher Pras severity score (5.86) and a greater proportion of moderate disease severity (56.5%). The most common clinical manifestations were abdominal pain (90.6%), fever (84.2%) and arthralgia (58.7%).

CONCLUSION

Individuals with VUS variants in the MEFV gene may present with a classic FMF phenotype characterized by mild to moderate disease activity. Patients carrying various VUS genotypes in the MEFV gene exhibit comparable clinical features with some degree of variation.

Familial Mediterranean Fever; Recent Advances, Future Prospectives

Familial Mediterranean Fever (FMF) is the prototype and most common autoinflammatory disease that is particularly frequent in populations originating from the Mediterranean basin. It is characterized by episodes of recurrent inflammation lasting 2-3 days. Colchicine is the mainstay therapy, which decreases the number of attacks and eventually prevents amyloidosis, the most worrisome complication of uncontrolled FMF. It is an autosomal recessive disease. The high rate of MEFV gene mutations in specific populations has been discussed as the result of an evolutionary advantage. Tel-Hashomer criteria were the first set of criteria primarily designed for adults. Recently, the Eurofever/PRINTO group has validated a new set of classification criteria for FMF, including clinical and genetic variables. Colchicine intolerance is an important problem and limits the ability to reach an effective dose. In these groups of patients, adding an alternative biological treatment (anti IL-1 agents) is recommended. Several tools such as FMF50, AIDAI, ADDI, ISSF and MASIF have been proposed to evaluate and quantify the disease activity and organ damage. Ongoing research should clarify the exact mechanisms causing FMF attacks and phenotypic variabilities between the patients; further translational research requires the implementation of proteomics and epigenetics signatures to elucidate the pathogenesis.

R202Q homozygosity of Mediterranean fever gene is associated with atypical clinical phenotype of familial Mediterranean fever

OBJECTIVE

Apart from the classical phenotypes, familial Mediterranean fever (FMF) has several atypical manifestations making its diagnosis quite challenging. Our aim was to address the characteristics of FMF patients and the clinical importance of R202Q variant in a large cohort of patients from Greece.

METHODS

Prospectively collected data from 321 FMF patients were retrospectively reviewed and analyzed. All patients were tested for Mediterranean fever gene/MEFV alterations in exon-2 and exon-10, by non-isotopic RNase-cleavage assay, and subsequent sequencing analysis. Hardy-Weinberg equilibrium (HWE) was used to assess R202Q allelic and genotypic frequencies in relation to FMF HWE.

RESULTS

Among 223 FMF patients with available follow-up data, 54.3 % were females and mean age at diagnosis was 35.4 ± 16.7 years. Regarding genetic analysis, 38.2 % had pathogenic/likely pathogenic variants, 12.1 % had variants of unknown significance, 16.1 % were R202Q homozygotes, while 33.6 % had negative genetic test. As explained by the strong deviation from HWE observed among FMF patients (p < 0.0001), R202Q homozygosity is considered disease-related. R202Q homozygosity was identified mainly among native Greeks (77.8 %) and was associated with a higher age of disease onset (p < 0.001) and a lower occurrence of abdominal pain (p < 0.001) compared to pathogenic/likely pathogenic variants. R202Q homozygosity (10/30, 33.3 %) was associated with atypical disease phenotype (OR: 1.95, 95 %CI: 1.24-3.08, p = 0.004) after adjustment for age, origin and sex.

DISCUSSION AND CONCLUSION

Excess R202Q homozygosity was observed among Greek FMF patients presenting atypical/non-criteria manifestations. In patients with periodic fevers and atypical clinical phenotype, the identification of R202Q homozygosity is linked with the diagnosis of FMF.

A novel seven-tier framework for the classification of MEFV missense variants using adaptive and rigid classifiers

There is a great discrepancy between the clinical categorization of MEFV gene variants and in silico tool predictions. In this study, we developed a seven-tier classification system for MEFV missense variants of unknown significance and recommended a generalized pipeline for other gene classifications. We extracted 12,017 human MEFV gene variants from the Ensembl database. After extraction, we detected 6034 missense variants. In the next step, we selected 42 in silico tools for our classification model. We determined the optimal value via the scores from three in silico tools. For the implementation of machine learning methods, we used two bagging methods and two boosting methods. After predicting known variants, we applied our model to 5507 variants of unknown significance. In the final stage, we applied the developed framework to the entire dataset to rigorously evaluate its classification performance and validate its potential clinical utility. The XGBoost model achieved the highest accuracy at 0.9882 (± 0.0295), followed by Extremely Randomized Trees (0.9835 ± 0.0335), Random Forest (0.9788 ± 0.0158), and AdaBoost (0.9671 ± 0.0815). Following the refinement of the dataset and the introduction of a novel classification and clustering methodology, the proportion of known variants increased from 6.9 to 29.4%, marking a 4.3-fold relative improvement. Furthermore, we identified two novel hotspot regions and one tolerant site, offering valuable insights into the functional structure of the pyrin protein. Rigid and adaptive classifiers offer an innovative framework for VOUS classification, integrating a grayscale interpretation system with cutting-edge in silico tools and machine learning algorithms. This approach not only improves the accuracy of MEFV gene variant classification but also identifies new hotspot regions for functional studies, paving the way for scalable applications to other genes and might contribute to advancing precision genomic medicine in the future.

Mechanisms of NLRP3 activation and inhibition elucidated by functional analysis of disease-associated variants

The NLRP3 inflammasome is a multiprotein complex that mediates caspase-1 activation and the release of proinflammatory cytokines, including interleukin (IL)-1β and IL-18. Gain-of-function variants in the gene encoding NLRP3 (also called cryopyrin) lead to constitutive inflammasome activation and excessive IL-1β production in cryopyrin-associated periodic syndromes (CAPS). Here we present functional screening and automated analysis of 534 NLRP3 variants from the international INFEVERS registry and the ClinVar database. This resource captures the effect of NLRP3 variants on ASC speck formation spontaneously, at low temperature, after inflammasome stimulation and with the specific NLRP3 inhibitor MCC950. Most notably, our analysis facilitated the updated classification of NLRP3 variants in INFEVERS. Structural analysis suggested multiple mechanisms by which CAPS variants activate NLRP3, including enhanced ATP binding, stabilizing the active NLRP3 conformation, destabilizing the inactive NLRP3 complex and promoting oligomerization of the pyrin domain. Furthermore, we identified pathogenic variants that can hypersensitize the activation of NLRP3 in response to nigericin and cold temperature exposure. We also found that most CAPS-related NLRP3 variants can be inhibited by MCC950; however, NLRP3 variants with changes to proline affecting helices near the inhibitor binding site are resistant to MCC950, as are variants in the pyrin domain, which likely trigger activation directly with the pyrin domain of ASC. Our findings could help stratify the CAPS population for NLRP3 inhibitor clinical trials and our automated methodologies can be implemented for molecules with a different mechanism of activation and in laboratories worldwide that are interested in adding new functionally validated NLRP3 variants to the resource. Overall, our study provides improved diagnosis for patients with CAPS, mechanistic insight into the activation of NLRP3 and stratification of patients for the future application of targeted therapeutics.

Efficacy and safety profile of biotechnological agents and Janus kinase inhibitors in VEXAS syndrome: data from the international AIDA Network VEXAS registry

BACKGROUND

VEXAS syndrome, a recently identified systemic autoinflammatory disorder, poses new diagnostic and management challenges. Based on experience with other autoinflammatory diseases, anti-interleukin (IL)-1, anti-IL-6, anti-tumor necrosis factor (TNF) biotechnological agents, and Janus kinase inhibitors (JAKis) have been widely employed in VEXAS patients. The aim of this study is to evaluate the global effectiveness and safety of biotechnological agents and JAKis using data from the real-world context.

METHODS

Clinical, laboratory, and therapeutic data from VEXAS patients were obtained from the international AIDA Network VEXAS registry.

RESULTS

In total, 69 VEXAS patients were enrolled in the study. Among them, 12 patients (13 treatment courses) received IL-1 inhibitors, 12 patients (13 treatment courses) were administered anti-IL-6 agents, 8 patients (9 treatment courses) were treated with anti-TNF agents, and 16 patients (17 treatment courses) were treated with JAKis. A complete response was observed in 3 patients (23%) treated with anti-IL-1 agents, 2 patients (15%) receiving IL-6 inhibitors, 1 patient (11%) receiving TNF inhibitors, and 4 patients (23.5%) treated with JAKis. The mean prednisone (or equivalent) dosage significantly decreased during anti-IL-1 treatment (p = 0.01), while glucocorticoids changed during anti-IL-6, anti-TNF, and JAKi treatment in a non-significant fashion. A total of 21 patients experienced adverse events, 3 of which led to death (gut perforation, Legionnaires' disease, and infectious pneumonia) while on JAKis; treatment withdrawal was required for 8 out of 21 patients.

CONCLUSION

IL-1 and IL-6 inhibitors, along with JAKis, represent promising therapeutic options for VEXAS patients, albeit careful monitoring is mandatory to control disease activity and ensure safety.

Characteristics and outcomes of adult patients with familial Mediterranean fever: Comparison of patients with one versus two pathogenic exon 10 MEFV mutations

OBJECTIVE

To describe the main features and outcomes of a large cohort of adult familial Mediterranean fever (FMF) patients with one pathogenic MEFV mutations and compare them to FMF patients displaying 2 pathogenic MEFV mutations.

METHODS

In a retrospective single-referential French center cohort of 581 patients with FMF, 178 FMF patients with one pathogenic mutation were retrieved and compared to 403 patients with 2 pathogenic MEFV mutations. The diagnosis of FMF was based on the Eurofever/PRINTO classification criteria for all patients, and they had all been sequenced for MEFV. Patients with M694V/E148Q genotype were also compared to M694V/WT patients.

RESULTS

Compared to FMF patients with 2 pathogenic MEFV mutations, patients with one pathogenic mutation showed significantly higher age at diagnosis and at disease onset (25 vs 10years and 12 vs 5years, P<0.001, respectively), higher personal history (21% vs 5%, P<0.001) or familial history (13% vs 5%, P=0.001) of recurrent aphthous stomatitis (RAS) and higher body mass index (BMI) (24 vs 23kg/m2, P<0.05). Conversely, patients with one mutation showed no AA amyloidosis (0 vs 6%, P=0.001) and lower colchicine dosage (P<0.001) than patients with two pathogenic MEFV mutations. These differences remained significant after adjustments for age at disease onset (beginning in childhood or adulthood). No clinical difference was found between patients with M694V/E148Q and M694V/WT.

CONCLUSION

Adult FMF patients with a single pathogenic MEFV mutation display specific clinical features as well as different evolution compared to patients with 2 pathogenic MEFV mutations.

The effect of gene dosage and age at the disease onset on the severity of familial Mediterranean fever

OBJECTIVE

To compare the demographic and clinical characteristics of familial Mediterranean fever (FMF) patients according to age at disease onset and evaluate the dose effect of the number of pathogenic or likely pathogenic exon 10 mutations of the MEFV gene on disease severity.

METHODS

This medical record review study was performed on 485 pediatric FMF patients with uni- or biallelic exon 10 mutations of the MEFV gene (M694V, M694I, M680I, V726A, R761H, T267I). Patients were grouped according to age at disease onset (Group 1:<6 years; Group 2:6-11 years; and Group 3:>11 years). Disease severity was assessed by the international severity scoring system for FMF (ISSF).

RESULTS

Of the patients, 294 (60.6%) were classified in Group 1, 152 (31.4%) in Group 2 and 39 (8%) in Group 3. The mean elapsed time to diagnosis was 26.7 ± 27.4 months in Group 1 and was higher than the other groups (p < 0.001). During the attack, fever was higher in Group 1, arthritis in Group 2, and chest pain in Group 3 (p < 0.001). The median ISSF score was similar in patients with uni- or biallelic mutations in Group 1 and 3 (p = 0.086, p = 0.35, respectively) but lower in heterozygous patients in Group 2 (p < 0.001). In Groups 1 and 2, mild disease severity was higher in heterozygotes, while moderate disease severity was higher in homozygotes (p = 0.034, p = 0.001, respectively).

CONCLUSION

The presence of pathogenic or likely pathogenic homozygous or compound heterozygous mutations in exon 10 of the MEFV gene in patients with early-onset disease is associated with a more severe disease course compared to patients with heterozygous mutations. The gene dose effect of the number of mutations on disease severity is more common in children aged 6-11 years.

The journey of MEFV heterozygous children: with or without colchicine

To investigate the rate of colchicine use in the longitudinal follow-up of familial Mediterranean fever (FMF) carriers and identify variables that could predict the necessity of colchicine treatment in this group. The study was conducted in 9 pediatric rheumatology centers. The files of children with MEFV gene carriers were retrospectively reviewed between February 2014 and May 2024. The study included 869 children with a median follow-up duration of 28 months (12-124). In most of the cases (n: 369; 43.5%), MEFV gene analysis was ordered by a pediatric rheumatologist, while in 228 children (26.2%), gene analysis was conducted at the request of a geneticist. The most common reason for ordering MEFV gene analysis was the presence of FMF-like symptoms (n: 349; 40.1%), followed by genetic screening due to a family history of FMF in relatives (n: 267; 30.7%). Colchicine therapy was initiated in 13.9% (n: 121) of the children. Variables that showed statistically significant differences in colchicine users included having a family history of amyloidosis, the MEFV gene ordered by a pediatric rheumatologist, and the presence of FMF-like symptoms. Conclusions: A small number of MEFV gene carriers develop FMF symptoms during the follow-up period, most commonly within 2-3 years. We do not recommend routine family screening for the MEFV gene after the diagnosis of an index patient unless there is a history of amyloidosis in the family or individuals having FMF-like symptoms.

Cost-saving approach with screening of selected variants in genetic diagnosis in Turkish pediatric familial Mediterranean fever patients: a single center longitudinal study

BACKGROUND

The aim of this study was to investigate whether a short exon screening consisting of selected variants could confirm the diagnosis in patients with a preliminary diagnosis of familial Mediterranean fever (FMF), thus providing a cost-saving alternative to a comprehensive MEditerranean FeVer (MEFV) gene sequence analysis test.

METHODS

This observational study on pediatric patients focused on clinically suspected FMF cases without prior genetic analysis. Participants met the Turkish pediatric FMF criteria. They underwent short exon screening for M694V, M680I, V726A, and E148Q variants. Those who were heterozygous or negative on short exon screening received further MEFV gene sequence analysis.

RESULTS

The study involved 1557 patients. Pathogenic variants in both alleles of the MEFV gene were found in 611 patients (39.2%), and a high-penetrance variant in heterozygosity or an E148Q variant on the other allele was found in 643 patients (41.3%). A further 189 patients (12.1%) had one or two E148Q variants. Short-exon screening was negative in 114 patients (7.6%). Of the 876 patients who underwent MEFV gene sequence analysis, additional variants were found in 72 of the 762 initially heterozygous patients. Of the 114 initially negative patients, 34 had homozygous or compound heterozygous variants, and 74 had heterozygous variants. Ultimately, only 6 patients yielded negative results in the MEFV gene sequence analysis.

CONCLUSION

The short exon screening for common MEFV mutations offers a practical and cost-saving alternative to comprehensive MEFV gene sequence analysis in populations with a high prevalence of FMF.

A plasmonic biosensor pre-diagnostic tool for Familial Mediterranean Fever

Familial Mediterranean Fever (FMF) is an autosomal recessive genetic disorder, primarily observed in populations around the Mediterranean Sea, linked to MEFV gene mutations. These mutations disrupt inflammatory responses, increasing pyrin-protein production. Traditional diagnosis relies on clinical symptoms, family history, acute phase reactants, and excluding similar syndromes with MEFV testing, which is expensive and often inconclusive due to heterozygous mutations. Here, we present a biosensor platform that detects differences in pyrin-protein levels between healthy and affected individuals, offering a cost-effective alternative to genetic testing. Our platform uses gold nanoparticle-based plasmonic chips enhanced with anti-pyrin antibodies, achieving a detection limit of 0.24 ng/mL with high specificity. The system integrates an optofluidic system and visible light spectroscopy for real-time analysis, with signal stability maintained for up to six months. Our technology will enhance FMF diagnosis accuracy, enabling early treatment initiation and providing a cost-effective alternative to genetic testing, thus improving patient care.

The significance of carrying MEFV variants in symptomatic and asymptomatic individuals

Familial Mediterranean fever (FMF) is an autoinflammatory disease characterized by recurrent attacks of fever, serositis (peritonitis, pleuritis, or synovitis), and erysipelas-like erythema. Genetic variants in the MEFV gene are associated with this disease. Familial Mediterranean fever is considered an autosomal recessive disease. However, in Middle Eastern countries, a third of the patients expressing FMF manifestations, carry a single mutation only. Moreover, some cases of pure dominant inheritance linked to specific single MEFV variants have also been described. This complex inheritance of MEFV-associated inflammatory diseases poses a serious challenge when interpreting the results of genetic testing in patients having recurrent fever syndromes. In addition, in certain situations, asymptomatic individuals may be incidentally found to carry MEFV variants. These cases pose the question of their exact diagnosis and whether they should be treated. Previous studies have focused on genetic results interpretations among symptomatic patients. In the current article, we would like to elaborate on the genetic interpretation in cases of symptomatic individuals suspected to have FMF and on asymptomatic individuals carrying MEFV variants. We aim to assist physicians unfamiliar with FMF to cope with genetic results interpretation when facing symptomatic and asymptomatic individuals carrying MEFV variants and suggest a management plan accordingly.

Familial Mediterranean Fever: An Autoinflammatory Genetic Disorder

A man in his 30s with a past medical history of fever episodes of unknown origin associated with abdominal and chest pain, arthralgias, and two episodes of aseptic meningitis, beginning at teenage, presented at the emergency department with similar symptoms and tinnitus with one week of evolution. A physical examination revealed left peripheral facial paresis and bilateral sensorineural deafness. From the etiological investigation, numerous tests were conducted to rule out infectious, paraneoplastic, and immune disorders, all of which yielded unremarkable results. He began a high dose of corticosteroids, leading to complete clinical recovery. Monogenic autoinflammatory syndrome disease was suspected. A genetic test confirmed the diagnosis of familial Mediterranean fever. He began taking colchicine daily without any complications. To avoid future complications, the authors aim to emphasize the importance of recognizing this rare cause of fever.

A20 haploinsufficiency disturbs immune homeostasis and drives the transformation of lymphocytes with permissive antigen receptors

Genetic TNFAIP3 (A20) inactivation is a classical somatic lymphoma lesion and the genomic trait in haploinsufficiency of A20 (HA20). In a cohort of 34 patients with HA20, we show that heterozygous TNFAIP3 loss skews immune repertoires toward lymphocytes with classical self-reactive antigen receptors typically found in B and T cell lymphomas. This skewing was mediated by a feed-forward tumor necrosis factor (TNF)/A20/nuclear factor κB (NF-κB) loop that shaped pre-lymphoma transcriptome signatures in clonally expanded B (CD81, BACH2, and NEAT1) or T (GATA3, TOX, and PDCD1) cells. The skewing was reversed by anti-TNF treatment but could also progress to overt lymphoma. Analysis of conditional TNFAIP3 knock-out mice reproduced the wiring of the TNF/A20/NF-κB signaling axis with permissive antigen receptors and suggested a distinct regulation in B and T cells. Together, patients with the genetic disorder HA20 provide an exceptional window into A20/TNF/NF-κB-mediated control of immune homeostasis and early steps of lymphomagenesis that remain clinically unrecognized.

IL-1 Inhibitors in the Treatment of Familial Mediterranean Fever: Treatment Indications and Clinical Features in a Large Real-World Cohort

Background: The accruing evidence about the efficacy of anti-IL-1 agents in Familial Mediterranean Fever (FMF) patients led to their widespread off-label use. Therefore, identifying precise indications and clinical characteristics of IL-1i-warranting patients are important. This study investigated the clinical characteristics and treatment indications of patients with FMF requiring interleukin 1 inhibition therapy (IL-1i). Methods: Hospital records of FMF patients attending a tertiary care center at the Department of Rheumatology, University of Health Sciences, Basaksehir Cam and Sakura City Hospital were retrospectively analyzed. Data on symptoms and disease manifestations, age of symptom onset, time to diagnosis, MEFV variants, type of treatment, and their indications were collected. Results: Between June 2020 and March 2023, 312 FMF patients were identified. The mean age at the onset of symptoms was 14.0, and the mean time to diagnosis was 11.9 years. In total, 87.1% of patients were receiving colchicine monotherapy, while the remaining 11.8% warranted IL-1i. Clinical symptoms and flare manifestations did not show a significant difference between the two groups. However, patients receiving IL-1i started having symptoms at younger age (11.5 vs. 14.5, p = 0.042) and time to diagnosis was longer (18.2 vs. 11.0, p < 0.01). M694V homozygosity was more common in patients receiving IL-1i. Indications for patients receiving IL-1i were colchicine resistance (8.0%), secondary amyloidosis (5.1%), and colchicine intolerance (2.2%). Conclusions: This study shows that a subset of FMF patients, particularly those with a more severe phenotype with an earlier disease onset and M694V homozygosity, require IL-1i treatment despite the overall good efficacy and tolerability of colchicine, primarily due to colchicine resistance, intolerance, or complications such as amyloidosis.

Novel chemotype NLRP3 inhibitors that target the CRID3-binding pocket with high potency

The NLRP3 inflammasome plays a central role in various human diseases. Despite significant interest, most clinical-grade NLRP3 inhibitors are derived from sulfonylurea inhibitor CRID3 (also called MCC950). Here, we describe a novel chemical class of NLRP3-inhibiting compounds (NIC) that exhibit potent and selective NLRP3 inflammasome inhibition in human monocytes and mouse macrophages. BRET assays demonstrate that they physically interact with NLRP3. Structural modeling further reveals they occupy the same binding site of CRID3 but in a critically different conformation. Furthermore, we show that NIC-11 and NIC-12 lack the off-target activity of CRID3 against the enzymatic activity of carbonic anhydrases I and II. NIC-12 selectively reduces circulating IL-1ß levels in the LPS-endotoxemia model in mice and inhibits NLRP3 inflammasome activation in CAPS patient monocytes and mouse macrophages with about tenfold increased potency compared with CRID3. Altogether, this study unveils a new chemical class of highly potent and selective NLRP3-targeted inhibitors with a well-defined molecular mechanism to complement existing CRID3-based NLRP3 inhibitors in pharmacological studies and serve as novel chemical leads for the development of NLRP3-targeted therapies.

Orbital/ocular inflammatory involvement in VEXAS syndrome: Data from the international AIDA network VEXAS registry

VEXAS syndrome is a recently described monogenic autoinflammatory disease capable of manifesting itself with a wide array of organs and tissues involvement. Orbital/ocular inflammatory manifestations are frequently described in VEXAS patients. The objective of this study is to further describe orbital/ocular conditions in VEXAS syndrome while investigating potential associations with other disease manifestations. In the present study, twenty-seven out of 59 (45.8 %) VEXAS patients showed an inflammatory orbital/ocular involvement during their clinical history. The most frequent orbital/ocular affections were represented by periorbital edema in 8 (13.6 %) cases, episcleritis in 5 (8.5 %) patients, scleritis in 5 (8.5 %) cases, uveitis in 4 (6.8 %) cases, conjunctivitis in 4 (6.8 %) cases, blepharitis in 3 (5.1 %) cases, orbital myositis in 2 (3.4 %) cases. A diagnosis of systemic immune-mediated disease was observed in 15 (55.6 %) cases, with relapsing polychondritis diagnosed in 12 patients. A significant association was observed between relapsing polychondritis and orbital/ocular involvement in VEXAS syndrome (Relative Risk: 2.37, 95 % C.I. 1.03-5.46, p = 0.048). Six deaths were observed in the whole cohort of patients after a median disease duration of 1.2 (IQR=5.35) years, 5 (83.3 %) of which showed orbital/ocular inflammatory involvement. In conclusion, this study confirms that orbital/ocular inflammatory involvement is a common finding in VEXAS patients, especially when relapsing polychondritis is diagnosed. This makes ophthalmologists a key figure in the diagnostic process of VEXAS syndrome. The high frequency of deaths observed in this study seems to suggest that patients with orbital/ocular involvement may require increased attention and more careful follow-up.

Risk for cancer development in familial Mediterranean fever and associated predisposing factors: an ambidirectional cohort study from the international AIDA Network registries

OBJECTIVE

Inflammation has been associated with an increased risk for cancer development, while innate immune system activation could counteract the risk for malignancies. Familial Mediterranean fever (FMF) is a severe systemic inflammatory condition and also represents the archetype of innate immunity deregulation. Therefore, the aim of this study is to investigate the risk for cancer development in FMF.

METHODS

The risk ratio (RR) for malignancies was separately compared between FMF patients and fibromyalgia subjects, Still's disease patients and Behçet's disease patients. Clinical variables associated with cancer development in FMF patients were searched through binary logistic regression.

RESULTS

580 FMF patients and 102 fibromyalgia subjects, 1012 Behçet's disease patients and 497 Still's disease patients were enrolled. The RR for the occurrence of malignant neoplasms was 0.26 (95% Confidence Interval [CI.] 0.10-0.73, p=0.006) in patients with FMF compared to fibromyalgia subjects; the RR for the occurrence of malignant cancer was 0.51 (95% CI. 0.23-1.16, p=0.10) in FMF compared to Still's disease and 0.60 (95% CI. 0.29-1.28, p=0.18) in FMF compared to Behçet's disease. At logistic regression, the risk of occurrence of malignant neoplasms in FMF patients was associated with the age at disease onset (β1 = 0.039, 95% CI. 0.001-0.071, p=0.02), the age at the diagnosis (β1 = 0.048, 95% CI. 0.039-0.085, p=0.006), the age at the enrolment (β1 = 0.05, 95% CI. 0.007-0.068, p=0.01), the number of attacks per year (β1 = 0.011, 95% CI. 0.001- 0.019, p=0.008), the use of biotechnological agents (β1 = 1.77, 95% CI. 0.43-3.19, p=0.009), the use of anti-IL-1 agents (β1 = 2.089, 95% CI. 0.7-3.5, p=0.002).

CONCLUSIONS

The risk for cancer is reduced in Caucasic FMF patients; however, when malignant neoplasms occur, this is more frequent in FMF cases suffering from a severe disease phenotype and presenting a colchicine-resistant disease.

Genetically transitional disease: conceptual understanding and applicability to rheumatic disease

In genomic medicine, the concept of genetically transitional disease (GTD) refers to cases in which gene mutation is necessary but not sufficient to cause disease. In this Perspective, we apply this novel concept to rheumatic diseases, which have been linked to hundreds of genetic variants via association studies. These variants are in the 'grey zone' between monogenic variants with large effect sizes and common susceptibility alleles with small effect sizes. Among genes associated with rare autoinflammatory diseases, many low-frequency and/or low-penetrance variants are known to increase susceptibility to systemic inflammation. In autoimmune diseases, hundreds of HLA and non-HLA genetic variants have been revealed to be modest- to moderate-risk alleles. These diseases can be reclassified as GTDs. The same concept could apply to many other human diseases. GTD could improve the reporting of genetic testing results, diagnostic yields, genetic counselling and selection of therapy, as well as facilitating research using a novel approach to human genetic diseases.

Canakinumab treatment real world evidence in 3 monogenic periodic fever syndromes in 2009-2022: an interim analysis using the French JIR cohort database

BACKGROUND

Our study aimed to provide real-world evidence on the treatment patterns, effectiveness and safety of canakinumab in France in Familial Mediterranean Fever (FMF), Mevalonate Kinase Deficiency (MKD), and Tumor necrosis factor Receptor Associated Periodic Syndrome (TRAPS).

METHODS

This study used the JIR cohort, a multicentre international registry created in 2013 to collect data on patients with juvenile inflammatory rheumatic diseases. French patients diagnosed with FMF, MKD or TRAPS and treated with canakinumab were included in this study.

RESULTS

31 FMF, 26 MKD and 7 TRAPS patients received canakinumab during the study period. Most of them initiated canakinumab at the recommended dose of 2 mg/kg or 150 mg, but less than half of FMF and MKD patients initiated it at the recommended frequency (every 4 weeks). Two years after initiation, the rate of patients still on treatment was 78.1% in FMF, 73.7% in MKD, and 85.7% in TRAPS patients. While the dose per injection remained globally the same over the course of the treatment, some adjustments of the dose intervals were observed. Six patients had a severe adverse event reported. Of those, three were possibly related to canakinumab.

CONCLUSION

This interim analysis showed a good maintenance of canakinumab treatment 2 years after initiation and confirmed its safety profile in real-life practice in France in patients diagnosed with FMF, MKD and TRAPS. The high variety of dose and interval combinations observed in canakinumab treated patients let suppose that physicians adapt the posology to individual situations rather than a fixed treatment plan.

The discovery of NLRP3 and its function in cryopyrin-associated periodic syndromes and innate immunity

From studies of individual families to global collaborative efforts, the NLRP3 inflammasome is now recognized to be a key regulator of innate immunity. Activated by a panoply of pathogen-associated and endogenous triggers, NLRP3 serves as an intracellular sensor that drives carefully coordinated assembly of the inflammasome, and downstream inflammation mediated by IL-1 and IL-18. Initially discovered as the cause of the autoinflammatory spectrum of cryopyrin-associated periodic syndrome (CAPS), NLRP3 is now also known to play a role in more common diseases including cardiovascular disease, gout, and liver disease. We have seen cohesion in results from clinical studies in CAPS patients, ex vivo studies of human cells and murine cells, and in vivo murine models leading to our understanding of the downstream pathways, cytokine secretion, and cell death pathways that has solidified the role of autoinflammation in the pathogenesis of human disease. Recent advances in our understanding of the structure of the inflammasome have provided ways for us to visualize normal and mutant protein function and pharmacologic inhibition. The subsequent development of targeted therapies successfully used in the treatment of patients with CAPS completes the bench to bedside translational loop which has defined the study of this unique protein.

Practical Approach to Diagnosis and Management of IL-1-Mediated Autoinflammatory Diseases (CAPS, TRAPS, MKD, and DIRA)

Systemic autoinflammatory diseases (SAIDs) are a group of rare genetic and nongenetic immune dysregulatory disorders associated with high morbidity and mortality if left untreated. Therefore, early diagnosis and initiation of targeted treatment is vital in SAID patients to control the disease activity and prevent long-term immune-mediated damage. A specific group of genetically defined SAIDs is associated with increased inflammasome-mediated production of active interleukin (IL)-1. Even though progress in immunobiology and genetics has brought forth diagnostic tools and novel treatments that have been described in the literature extensively, many challenges remain in the clinical setting. Some challenges that health care providers may face on a day-to-day basis include the requirement of a multidisciplinary approach due to the complexity of these diseases, limited evidence-based treatment options, and barriers to access available therapies. Primarily, IL-1 inhibitors anakinra, canakinumab, and rilonacept are used to control the inflammation in these patients, with the goal of achieving sustainable remission. Recently published provisional points to consider from the European Alliance of Associations for Rheumatology (EULAR) and American College of Rheumatology (ACR) provide diagnosis, management, and monitoring recommendations for four IL-1-mediated autoinflammatory diseases: cryopyrin-associated periodic syndromes (CAPS), tumour necrosis factor receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD), and deficiency of the IL-1 receptor antagonist (DIRA). The goal of this paper is to aid health care professionals by providing a practical approach to diagnosis and management of these four IL-1 mediated SAIDs on the basis of the recent EULAR/ACR recommendations.

Knowledge and Current Practices in Monogenic Uveitis: An International Survey by IUSG and AIDA Network

INTRODUCTION

This study aims to explore awareness, knowledge, and diagnostic/therapeutic practices in monogenic uveitis (mU) among uveitis experts.

METHODS

This is an explorative, cross-sectional survey study. An anonymous, semi-structured, electronic survey was delivered to uveitis experts from the Autoinflammatory Diseases Alliance (AIDA) Network and International Uveitis Study Group (IUSG). We included respondents answering ≥ 50% of the survey.

RESULTS

Seventy-seven participants rated their knowledge of mU as proficient (3.9%), adequate (15.6%), sufficient (16.9%), or poor (63.6%). When asked about the first mU gene they thought of, 60.4% mentioned NOD2, 3.9% mentioned NLRP3 or MEFV, and 49.4% provided incorrect or no answers. Success rates in clinical scenarios varied from 15.6% to 55.8% and were higher for ophthalmologists working in multidisciplinary teams (p < 0.01). Genetic testing was ordered for suspected mU by 41.6% of physicians. The availability of molecular techniques did not significantly differ based on geography (p > 0.05). The public healthcare system ensured a higher percentage of tests prescribed were obtained by patients compared to private insurances (p < 0.00). In terms of disease-modifying anti-rheumatic drugs (DMARDs), tumor necrosis factor-α inhibitors were the most familiar to uveitis experts. The difficulties with off-label therapy procedures were the primary barrier to DMARDs prescription for patients with mU and correlated inversely with the obtained/prescribed drug ratio for interleukin-1 (p < 0.01) and interleukin-6 (p < 0.01) inhibitors.

CONCLUSIONS

This survey identifies proficiency areas, gaps, and opportunities for targeted improvements in patients care. The comprehensive outputs may inform evidence-based guidelines, empowering clinicians with standardized approaches, and drive an AIDA Network-IUSG unified effort to advance scientific knowledge and clinical practice.

Drugging the NLRP3 inflammasome: from signalling mechanisms to therapeutic targets

Diseases associated with chronic inflammation constitute a major health burden across the world. As central instigators of the inflammatory response to infection and tissue damage, inflammasomes - and the NACHT, LRR and PYD domain-containing protein 3 (NLRP3) inflammasome in particular - have emerged as key regulators in diverse rheumatic, metabolic and neurodegenerative diseases. Similarly to other inflammasome sensors, NLRP3 assembles a cytosolic innate immune complex that activates the cysteine protease caspase-1, which in turn cleaves gasdermin D (GSDMD) to induce pyroptosis, a regulated mode of lytic cell death. Pyroptosis is highly inflammatory, partly because of the concomitant extracellular release of the inflammasome-dependent cytokines IL-1β and IL-18 along with a myriad of additional danger signals and intracellular antigens. Here, we discuss how NLRP3 and downstream inflammasome effectors such as GSDMD, apoptosis-associated speck-like protein containing a CARD (ASC) and nerve injury-induced protein 1 (NINJ1) have gained significant traction as therapeutic targets. We highlight the recent progress in developing small-molecule and biologic inhibitors that are advancing into the clinic and serving to harness the broad therapeutic potential of modulating the NLRP3 inflammasome.

Disease severity and genotype-phenotype correlation in adult patients with familial Mediterranean fever

OBJECTIVES

To assess the relationships of disease severity with genotype and phenotype in adult familial Mediterranean fever patients.

METHODS

Two-hundred seventy-five patients included in the study were divided into four groups according to their mutations: Group 1, M694V homozygous; Group 2, M694V-other; Group 3, other-other; and Group 4, no meaningful gene variants. Disease severity was evaluated using the Pras disease severity score. The association between Pras scores and other possible predictors was assessed by the multiple linear regression analysis.

RESULTS

In this study, 12.4% of all patients were in Group 1, 55.3% were in Group 2, 26.5% were in Group 3, and 5.8% were in Group 4. Pras scores were higher in Group 1 than in Groups 2, 3, and 4 (post hoc pairwise comparisons; P = .001, P < .001, and P = .001, respectively). Age at disease onset and age at diagnosis were found moderately and strongly correlated with Pras scores. Patients with moderate and severe disease were intensely involved in Group 1.

CONCLUSIONS

Higher Pras scores, earlier age of symptoms and diagnosis, more frequent arthritis and erysipelas-like erythema, and higher colchicine dose are closely associated with M694V homozygous familial Mediterranean fever patients. These patients also have mostly moderate and severe disease severity.

Hydatidiform Mole-Between Chromosomal Abnormality, Uniparental Disomy and Monogenic Variants: A Narrative Review

A hydatidiform mole (HM) or molar pregnancy is the most common benign form of gestational trophoblastic disease characterized by a proliferation of the trophoblastic epithelium and villous edema. Hydatidiform moles are classified into two forms: complete and partial hydatidiform moles. These two types of HM present morphologic, histopathologic and cytogenetic differences. Usually, hydatidiform moles are a unique event, but some women present a recurrent form of complete hydatidiform moles that can be sporadic or familial. The appearance of hydatidiform moles is correlated with some genetic events (like uniparental disomy, triploidy or diandry) specific to meiosis and is the first step of embryo development. The familial forms are determined by variants in some genes, with NLRP7 and KHDC3L being the most important ones. The identification of different types of hydatidiform moles and their subsequent mechanisms is important to calculate the recurrence risk and estimate the method of progression to a malign form. This review synthesizes the heterogeneous mechanisms and their implications in genetic counseling.

Uveitis Associated with Monogenic Autoinflammatory Syndromes in Children

Monogenic autoinflammatory syndromes (MAISs), are caused by pathogenic genetic variants in the innate immune system, leading to dysregulation and aberrant inflammasome activation spontaneously or with minimal triggering. The diagnosis and treatment of MAISs can be intricate, relying on an increased recognition of potential differential diagnoses. This review examines the clinical features of MAIS, with a special focus on uveitis. It also evaluates treatment options and assesses the effects of activating molecular and cytokine pathways.

Next generation sequencing (NGS)-based approach to diagnosing Algerian patients with suspected inborn errors of immunity (IEIs)

The advent of next-generation sequencing (NGS) technologies has greatly expanded our understanding of both the clinical spectra and genetic landscape of inborn errors of immunity (IEIs). Endogamous populations may be enriched for unique, ancestry-specific disease-causing variants, a consideration that significantly impacts molecular testing and analysis strategies. Herein, we report on the application of a 2-step NGS-based testing approach beginning with targeted gene panels (TGPs) tailored to specific IEI subtypes and reflexing to whole exome sequencing (WES) if negative for Northwest Algerian patients with suspected IEIs. Our overall diagnostic yield of 57% is comparable to others broadly applying short-read NGS to IEI detection, but data from our localized cohort show some similarities and differences from NGS studies performed on larger regional IEI cohorts. This suggests the importance of tailoring diagnostic strategies to local demographics and needs, but also highlights ongoing concerns inherent to the application of genomics for clinical IEI diagnostics.

A novel TNFRSF1A mutation associated with TNF-receptor-associated periodic syndrome and its metabolic signature

OBJECTIVE

We describe a family with a novel mutation in the TNF Receptor Superfamily Member 1A (TNFRSF1A) gene causing TNF receptor-associated periodic syndrome (TRAPS) with renal AA amyloidosis.

METHODS

Case series of affected family members. We further investigated the plasma metabolome of these patients in comparison with healthy controls using mass spectrometry.

RESULTS

In all symptomatic family members, we detected the previously undescribed variant c.332A>G (p.Q111R) in the TNFRSF1A gene. Canakinumab proved an effective treatment option leading to remission in all treated patients. One patient with suspected renal amyloidosis showed near normalization of proteinuria under treatment. Analysis of the metabolome revealed 31 metabolic compounds to be upregulated and 35 compounds to be downregulated compared with healthy controls. The most dysregulated metabolites belonged to pathways identified as arginine biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, and cysteine and methionine metabolism. Interestingly, the metabolic changes observed in all three TRAPS patients seemed independent of treatment with canakinumab and subsequent remission.

CONCLUSION

We present a novel mutation in the TNFRSF1A gene associated with amyloidosis. Canakinumab is an effective treatment for individuals with this new likely pathogenic variant. Alterations in the metabolome were most prominent in the pathways related to arginine biosynthesis, tryptophan metabolism, and metabolism of cysteine and methionine, and seemed to be unaffected by treatment with canakinumab. Further investigation is needed to determine the role of these metabolomic changes in the pathophysiology of TRAPS.

The Effect of Clinical and Genetic Variables of Familial Mediterranean Fever Patients: Real Life Data

BACKGROUND

The Eurofever/the Pediatric Rheumatology International Trials Organization (PRINTO) classification criteria for familial Mediterranean fever (FMF) include a combination of clinical symptoms and genotype. The pathogenicity of gene variants associated with FMF is categorized by the International Study Group for Systemic Autoinflammatory Diseases (INSAID) classification criteria.

OBJECTIVE

The aim of this study was to evaluate the real-life impact and usefulness of the Eurofever/PRINTO classification criteria and the INSAID classification criteria in patients with FMF and their impact on treatment management.

METHODS

In this medical records review study, the files of FMF patients who met the Eurofever/PRINTO classification criteria were reviewed. The MEFV (MEditerranean FeVer) variants were grouped according to the INSAID classification criteria.

RESULTS

Of the 1062 patients, the female-to-male ratio was 1:1.01. In group 1, there were 150 patients (14.1%) who met the clinical criteria. Group 2 consisted of 912 patients (85.9%) who met the criteria according to genetic variants. The mean ages at symptom onset in groups 1 and 2 were 5.6 ± 3.8 and 1.5 ± 1.2 years, respectively ( p = 0.024). Whereas the mean annual attack frequency was 2.7 ± 3.1/year in group 1, it was 4.1 ± 2.3/year in group 2 ( p = 0.04). The pathogenic variant was higher in the colchicine-resistant group compared with the responders ( p = 0.12).

CONCLUSIONS

The Eurofever/PRINTO classification criteria may provide a new perspective on the diagnosis and clinical follow-up of FMF patients. Patients with a pathogenic variant who meet the Eurofever/PRINTO classification criteria including genetic variables have earlier onset of disease and more frequent attacks than those who meet the criteria including clinical variables. These patients need regular and closer follow-ups in terms of attack frequency, colchicine dose adjustment, and colchicine resistance.

Treat-to-target strategies for the management of familial Mediterranean Fever in children

BACKGROUND

The objective of this initiative was to develop a treat-to-target (T2T) approach for the management of patients with Familial Mediterranean Fever (FMF), including the definition of a complex treatment target, and establish strategies that improve patient care and long-term outcome.

METHODS

An initial set of statements as well as a flow chart visualising the proposed concept was developed. To adapt the preliminary statements to the current state of knowledge, a systematic literature search was performed and the modified statements were subject to a Delphi approach. To ensure the applicability of the statements in daily practice, an online survey was conducted among paediatric rheumatologists in Germany. In addition, data from the national AID-NET registry were analysed with respect to therapeutic response.

RESULTS

This T2T initiative yielded a total of 26 statements guiding FMF management with respect to diagnosis, treatment targets, treatment strategies and monitoring. The online survey identified cut-off values for inflammatory markers indicating treatment intensification and appropriate measures in case of colchicine intolerance or non-adherence. The analysis of data derived from the national AID-NET showed that colchicine therapy was successfully terminated in 61% of patients (27 out of 44) with heterozygous MEFV mutations. Multidimensional treatment targets incorporating objective and subjective reported outcome measures were developed. These provide the basis for stratifying patients into the following treatment paths: continue colchicine, persisting attacks / inflammation, colchicine intolerance, persisting arthritis, colchicine reduction and adjustment/reduction of biologics.

CONCLUSIONS

The proposed consensus treatment plan for the management of FMF incorporates multidimensional targets allowing transparent treatment decisions, which will promote personalised disease management and increase adherence to therapy.

A patient with tumor necrosis factor receptor-associated periodic syndrome misdiagnosed as Kawasaki disease: A case report and literature review

This article reports a case of tumor necrosis factor receptor-associated periodic syndrome (TRAPS) misdiagnosed as Kawasaki disease and summarizes the clinical features and therapeutic progress of TRAPS and the relationship between its clinical manifestations and gene mutations. We retrospectively analyzed a patient with tumor necrosis factor receptor superfamily member 1A (TNFRSF1A) -mutated auto-inflammatory disease who was misdiagnosed with Kawasaki disease in another hospital. The clinical features and therapeutic progress of TRAPS were analyzed by combining clinical features and gene reports of this case and literature review. TRAPS onset occurred in a female pediatric patient at the age of 4 months. The child and in his father at the age of 6 years, both of whom manifested periodic fever, and recurrent rash, as well as elevated leukocytes, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) during episodes but normal between episodes. This child carried a heterozygous mutation in TNFRSF1A located in the region 6442923-6442931 on chromosome 12. The nucleic acid alteration was: c.298 (exon3) _c.306 (exon3) 291 delCTCAGCTGC, resulting in a 3 amino acid deletion p.L100_C 102del 292 (p.Leu100_Cys102del) (NM_001065). After etanercept treatment, the symptoms of fever and rash disappeared, and the levels of ESR, CRP, interleukin (IL)-1, IL-6, and TNF-α levels were normal. Subsequently, no liver, kidney, or cardiac amyloidosis and severe etanercept-related adverse events were observed at 1-year follow-up. TRAPS pathogenesis is associated with TNFRSF1A mutation, which is characterized by periodic episodes of fever, mostly accompanied by recurrent rashes, periorbital edema, abdominal pain, and serious complications of organ amyloidosis. Moreover, etanercept can effectively alleviate the clinical symptoms and high inflammation level of TRAPS.

Autoinflammatory Diseases/Periodic Fevers

Children with intermittent fevers present to pediatricians and other primary care child health providers for evaluation. Most patients will have self-limited, benign infectious illnesses. However, the possibility of a periodic fever syndrome should be considered if febrile episodes become recurrent over an extended period and are associated with particular signs and symptoms during each attack. This review discusses the current conceptualization of autoinflammatory diseases with specific focus and detail on familial Mediterranean fever; tumor necrosis factor receptor-associated periodic syndrome; mevalonate kinase deficiency; NLRP3-associated autoinflammatory disease; and periodic fever, aphthous stomatitis, pharyngitis, and adenitis. The genetic mutations associated with these clinical entities are identified, along with the historical nomenclature that predates the current pathogenetic understanding of these diseases. The episodic signs and symptoms seen across these periodic fever syndromes can be overlapping, but there are some distinguishing features that can be useful, and these are described. The disease course and potential complications, particularly amyloidosis, which is a variable risk in these conditions and a potential source of significant morbidity and mortality, are addressed. Treatment strategies are outlined, highlighting the advances in therapy that have resulted from the advent of proinflammatory cytokine-targeting biological agents.

A viewpoint on the genetic determinants of generalised pustular psoriasis

Generalised pustular psoriasis (GPP) is a rare and severe neutrophilic skin disorder, manifesting with acute episodes of pustulation and systemic upset. The discovery of recessive IL36RN mutations associated with GPP has transformed our understanding of disease drivers, paving the way for the development of targeted anti-IL36 therapeutics. In the light of these remarkable successes, this viewpoint reviews the significance of IL36RN mutations in GPP, their functional impact and their correlation with clinical phenotypes. It then covers the discovery of further genetic determinants (recessive MPO mutations) and risk factors (AP1S3 and CARD14 low-frequency variants) for the disease. It discusses the growing evidence for genetic complexity in GPP and concludes by outlining collaborative strategies that may be adopted to overcome the challenges ahead.

Case report: Birk-Landau-Perez syndrome linked to the gene-identification of additional cases and expansion of the phenotypic spectrum

Birk-Landau-Perez syndrome (BILAPES) is an autosomal recessive cerebro-renal syndrome associated with genetic defects in the SLC30A9 gene, initially reported in 2017 in six individuals belonging to a large Bedouin kindred. The SLC30A9 gene encodes a putative mitochondrial zinc transporter with ubiquitous expression, the highest found in the brain, kidney, and skeletal muscle. Since the first report, only one additional affected patient has been described, but there were some inconsistencies, such as hearing loss, failure to thrive, and neuroimaging findings between the clinical presentation of the disease in the Bedouin family and the second patient. Here, we present two more patients from a consanguineous Middle Eastern family with features of chronic kidney disease, neurodevelopmental regression, ataxia, hearing loss, and eye abnormalities, which were largely consistent with BILAPES. Whole-exome sequencing detected a homozygous in-frame deletion c.1049_1051delCAG (p.Ala350del) in the SLC30A9 gene, which was the same variant detected in the patients from the primary literature report and the variant segregated with disease in the family. However, in the patients described here, brain MRI showed cerebellar atrophy, which was not a cardinal feature of the syndrome from the primary report. Our findings provide further evidence for SLC30A9-associated BILAPES and contribute to defining the clinical spectrum.

Monocyte secretory profiling in a clinical and MEFV genotype-characterized cohort of Danish familial Mediterranean fever patients: diagnostic potential of CCL1 and CXCL1

OBJECTIVE

The autoinflammatory disease familial Mediterranean fever (FMF), characterized by recurrent attacks of sterile fever, serosal, and/or synovial inflammation, is caused by variants in the Mediterranean fever gene, MEFV, coding for the pyrin inflammasome sensor. The diagnosis of FMF is mainly based on clinical symptoms and confirmed by detection of disease-associated MEFV variants. However, the diagnosis is challenging among patients carrying variants of uncertain clinical significance (VUS). In this study, we aimed to identify potential FMF discriminatory diagnostic markers in a cohort of clinically characterized FMF patients.

METHOD

We established a cohort of clinically and MEFV genotype-characterized FMF patients by enrolling patients from major Danish hospitals (n = 91). The secretory profile of pyrin inflammasome-activated monocytes from healthy donors (HDs) and MEFV-characterized FMF patients (n = 28) was assessed by analysing cell supernatants for a custom-designed panel of 23 cytokines, chemokines, and soluble tumour necrosis factor receptors associated with monocyte and macrophage function.

RESULTS

MEFV genotypes in Danish FMF patients were associated with age at symptom onset (p < 0.05), FMF among relatives (p < 0.01), proportion of patients in colchicine treatment (p < 0.01), and treatment response (p < 0.05). Secretion of chemokines CCL1 and CXCL1 from pyrin-activated FMF monocytes was significantly decreased compared to HDs (p < 0.05), and could discriminate FMF patients with 'non-confirmatory' MEFV genotypes from HDs with 80.0% and 70.0% sensitivity for CCL1 and CXCL1, respectively (p < 0.05).

CONCLUSION

Our data suggest that a functional diagnostic assay based on CCL1 or CXCL1 levels in pyrin-activated patient monocytes may contribute to FMF diagnosis in patients with VUS.

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.

Biallelic NLRP7 variants in patients with recurrent hydatidiform mole: A review and expert consensus

Hydatidiform mole (HM) is an abnormal human pregnancy characterized by excessive growth of placental trophoblasts and abnormal early embryonic development. Following a first such abnormal pregnancy, the risk for women of successive molar pregnancies significantly increases. To date variants in seven maternal-effect genes have been shown to cause recurrent HMs (RHM). NLRP7 is the major causative gene for RHM and codes for NOD-like receptor (NLR) family pyrin domain containing 7, which belongs to a family of proteins involved in inflammatory disorders. Since its identification, all NLRP7 variants have been recorded in Infevers, an online registry dedicated to autoinflammatory diseases (https://infevers.umai-montpellier.fr/web/). Here, we reviewed published and unpublished recessive NLRP7 variants associated with RHM, scored their pathogenicity according to the American College of Medical Genetics classification, and recapitulated all functional studies at the level of both the patients and the conceptions. We also provided data on further variant analyses of 32 patients and genotypes of 36 additional molar pregnancies. This comprehensive review integrates published and unpublished data on NLRP7 and aims at guiding geneticists and clinicians in variant interpretation, genetic counseling, and management of patients with this rare condition.

Genetic testing in autoinflammatory diseases - past, current and future perspectives

INTRODUCTION

Autoinflammatory diseases (AID) are a group of rare monogenic illnesses, leading to uncontrolled activation of the innate immune system and presenting with recurrent flares of systemic and localized inflammation. Diagnosis is confirmed by the detection of a class IV or class V gene variant in an AID-related gene and improvements in sequencing techniques have enabled the discovery of new entities. The aim of our study is to explore the diagnostic yield of evolving genetic testing methods for AID and to determine whether increasing gene panels generate a higher diagnostic rate.

METHODS

Retrospective study of 2620 patients that underwent sequencing for a clinical suspicion of AID in Belgium, between January 2015 and December 2020. Sequencing was performed through a 10-gene panel between 2015 and 2017, a 25-gene panel between 2018 and 2020 and mendeliome technology with a 66- and a 502- in silico gene panel in 2020.

RESULTS

The rate of genetic diagnoses increased along with the expansion of the gene panel with a diagnostic yield of 15% with 10 genes, 16% with 25 genes and 23% with 502 genes.

CONCLUSION

Our study is the first nationwide study for autoinflammatory genetic testing and the first use of mendeliome technology for AID diagnosis. Although we confirmed that the bigger the gene panel, the higher the diagnostic rate, this technology generated inevitably a higher financial and human cost although the majority of diagnoses remained amongst the four original hereditary recurrent fevers (HRFs).

Incomplete penetrance of NOD2 C483W mutation underlining Blau syndrome

BACKGROUND

Blau syndrome (BS) is a rare autoinflammatory disorder with NOD2 gain-of-function mutation and characterized by autoactivation of the NFκB pathway. Classically considered a disease of high penetrance, reports on NOD2 mutations underlining BS with incomplete penetrance is limited.

CASE PRESENTATION

The proband is a 9-year-old girl presented with brownish annular infiltrative plaques and symmetric boggy polyarthritis over bilateral wrists and ankles. Her skin biopsy revealed noncaseating granulomas inflammation with multinucleated giant cells. A novel C483W NOD2 mutation was identify in the proband and her asymptomatic father. Functional examinations including autoactivation of the NFκB pathway demonstrated by in vitro HEK293T NOD2 overexpression test as well as intracellular staining of phosphorylated-NFκB in patient's CD11b⁺ cells were consistent with BS.

CONCLUSIONS

We reported a novel C483W NOD2 mutation underlining BS with incomplete penetrance. Moreover, a phosphorylated-NFκB intracellular staining assay of CD11b⁺ was proposed to assist functional evaluation of NFκB autoactivation in patient with BS.

FMF Kliniğine Alternatif Bir Bakış Açısı: MCP-1 (A-2518G) ve CCR2 (G190A) Polimorfizmleri ve MCP1 Ekspresyonu

Amaç: Ailevi Akdeniz Ateşi (AAA) otoinflamatuar bir hastalıktır ve çeşitli klinik bulgular olarak kendini gösterebilir. Kemokinler, inflamatuar sürecin önemli unsurlarıdır. MCP-1 ve onun reseptörü CCR2, FMF'de kritik roller oynayabilen monositler/makrofajlar için ana kemokinlerdir. Bundan dolayı MEFV gen fonksiyonunu etkileyebilecek MCP-1 (A-2518G) ve CCR2 (G190A) polimorfizmlerinin ve MCP-1 ekspresyon düzeyinin araştırılması amaçlanmıştır. Gereç ve Yöntem: FMF'li hastalar Tel-Hashomer kriterlerine göre belirlendi. Elde edilen kan örneklerinden DNA ve RNA izole edildi. Genotipleme analizi, PCR-RFLP tekniği ile yapıldı. Ayrıca Real-time PCR yöntemi ile ekspresyon analizleri yapıldı. Elde edilen sonuçlar istatistiksel olarak değerlendirildi. Bulgular: Çalışmaya toplam 229 birey (125 erkek ve 104 kadın) dahil edildi. Bunlardan 120 kişide FMF kliniği bulunurken, 107 kişide yoktu. Kalan iki kişi şüpheli klinik duruma sahipti. Çalışmaya alınan bireyler MEFV genotiplemesine göre değerlendirildiğinde ise 75 birey homozigot mutant, 77 birey Heterozigot saptanırken 77 birey ise MEFV geninde mutasyon taşımıyordu. Yapılan analizde Hem FMF kliniği hem de MEFV genotipleri ile MCP-1 (A-2518G) ve CCR2 (G190A) genotipleri arasında anlamlı bir ilişki bulunmadı. Ekspresyon analizinde, FMF kliniği olan hastalarda olmayanlara göre MCP-1 ekspresyonu artmış olarak saptandı. Ayrıca heterozigot MEFV grubunda mutasyonu olmayanlara göre MCP-1 ekspresyonu artmış olarak saptandı, Dahası homozigot MEFV grubunda MCP-1 ekspresyonu en yüksek düzeydeydi. Ek olarak, MCP-1 (A-2518G) genotiplendirmesine göre, MCP-1 ekspresyonu, Wild type gruba kıyasla hem homozigot hem de heterozigot gruplarda yükselmiştir. Sonuç: FMF hastalığında MCP-1 ekspresyonu artmış olup, bu durum FMF hastaları arasındaki klinik farklılıkları açıklayabilir. MEFV mutasyonları, MCP-1 transkripsiyonunu artırarak inflamasyonu şiddetlendirebilir. MCP-1(A-2518G) mutasyonlu hastalarda MCP-1 ekspresyonu artar, bu da FMF kliniğini ağırlaştırır. Anahtar Kelimeler: Ailevi Akdeniz Ateşi, MCP-1, CCR2, Expresyon analizi

The Autoinflammatory Diseases Alliance Registry of monogenic autoinflammatory diseases

OBJECTIVE

The present manuscript aims to describe an international, electronic-based, user-friendly and interoperable patient registry for monogenic autoinflammatory diseases (mAIDs), developed in the contest of the Autoinflammatory Diseases Alliance (AIDA) Network.

METHODS

This is an electronic platform, based on the Research Electronic Data Capture (REDCap) tool, used for real-world data collection of demographics, clinical, laboratory, instrumental and socioeconomic data of mAIDs patients. The instrument has flexibility, may change over time based on new scientific acquisitions, and communicate potentially with other similar registries; security, data quality and data governance are corner stones of the platform.

RESULTS

AIDA project will share knowledge and expertise on mAIDs. Since its start, 118 centers from 24 countries and 4 continents have joined the AIDA project. Fifty-nine centers have already obtained the approval from their local Ethics Committees. Currently, the platform counts 337 users (122 Principal Investigators, 210 Site Investigators, 2 Lead Investigators, and 3 data managers). The Registry collects baseline and follow-up data using 3,748 fields organized into 21 instruments, which include demographics, patient history, symptoms, trigger/risk factors, therapies, and healthcare information for mAIDs patients.

CONCLUSIONS

The AIDA mAIDs Registry, acts both as a research tool for future collaborative real-life studies on mAIDs and as a service to connect all the figures called to participate. On this basis, the registry is expected to play a pivotal role in generating new scientific evidence on this group of rare diseases, substantially improving the management of patients, and optimizing the impact on the healthcare system. NCT05200715 available at https://clinicaltrials.gov.

Determining the origin of different variants associated with familial mediterranean fever by machine-learning

A growing number of familial Mediterranean fever (FMF) patients in Israel do not have a single country of origin for all four grandparents. We aimed to predict the Mediterranean fever gene (MEFV) variant most likely to be found for an individual FMF patient, by a machine learning approach. This study was conducted at the Sheba Medical Center, a referral center for FMF in Israel. All Jewish referrals included in this study carried an FMF associated variant in MEFV as shown by genetic testing performed between 2001 and 2017. We introduced the term 'origin score' to capture the dose and different combinations of the grandparents' origin. A machine learning approach was used to analyze the data. In a total of 1781 referrals included in this study, the p.Met694Val variant was the most common, and the variants p.Glu148Gln and p.Val726Ala second and third most common, respectively. Of 26 countries of origin analyzed, those that increased the likelihood of a referral to carry specific variants were identified in North Africa for p.Met694Val, Europe for p.Val726Ala, and west Asia for p.Glu148Gln. Fourteen of the studied countries did not show a highly probable variant. Based on our results, it is possible to describe an association between modern day origins of the three most common MEFV variant types and a geographical region. A strong geographic association could arise from positive selection of a specific MEFV variant conferring resistance to endemic infectious agents.

The interplay between serine proteases and caspase-1 regulates the autophagy-mediated secretion of Interleukin-1 beta in human neutrophils

Neutrophils play major roles against bacteria and fungi infections not only due to their microbicide properties but also because they release mediators like Interleukin-1 beta (IL-1β) that contribute to orchestrate the inflammatory response. This cytokine is a leaderless protein synthesized in the cytoplasm as a precursor (pro-IL-1β) that is proteolytically processed to its active isoform and released from human neutrophils by secretory autophagy. In most myeloid cells, pro-IL-1β is processed by caspase-1 upon inflammasome activation. Here we employed neutrophils from both healthy donors and patients with a gain-of-function (GOF) NLRP3-mutation to dissect IL-1β processing in these cells. We found that although caspase-1 is required for IL-1β secretion, it undergoes rapid inactivation, and instead, neutrophil serine proteases play a key role in pro-IL-1β processing. Our findings bring to light distinctive features of the regulation of caspase-1 activity in human neutrophils and reveal new molecular mechanisms that control human neutrophil IL-1β secretion.

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.