Exploring S100A8/A9, neopterin, and MMP3 in familial Mediterranean fever.

Familial Mediterranean fever (FMF) is characterized by inflammatory attacks due to overactivation of pyrin inflammasome. This study aimed to investigate the reliability of S100A8/A9, neopterin, and matrix metalloproteinase 3 (MMP3) at monitoring subclinical inflammation and disease activity, and at differentiating FMF attacks from appendicitis, the most common misdiagnosis among FMF patients. Blood samples (n = 75), comprising from FMF patients during an attack (n = 20), the same FMF patients during the attack-free period (n = 14), patients with appendicitis (n = 24), and healthy volunteers (n = 17) were obtained. Duplicate determinations of S100A8/A9, neopterin, and MMP-3 levels were conducted using the enzyme-linked immunosorbent assay (ELISA). FMF patients with and without attack and patients with appendicitis had significantly elevated S100A8/A9 levels compared to healthy volunteers (P-values: < 0.001, 0.036, 0.002, respectively). Patients with appendicitis and FMF patients with and without attack had significantly increased serum neopterin levels compared to healthy volunteers (P-value: < 0.001). MMP3 levels were significantly higher among patients with appendicitis and FMF patients during attack compared to healthy controls (P-values: < 0.001, 0.001). Serum levels of S100A8/A9, neopterin, and MMP3 were increased significantly during attacks compared to attack-free periods among FMF patients (P-values: 0.03, 0.047, 0.007). S100A8/A9 emerges as a valuable marker for monitoring disease activity. Neopterin and S100A8/A9 might help physicians to monitor subclinical inflammation during the attack-free periods of FMF patients. MMP3 might aid in diagnosing FMF attacks when distinguishing between attack and attack-free periods is challenging.

Kidney Transplantation in Patients With AA Amyloidosis: Outcomes in a French Multicenter Cohort.

RATIONALE & OBJECTIVE: Outcomes of kidney transplantation for patients with renal AA amyloidosis are uncertain, with reports of poor survival and high rates of disease recurrence. However, the data are inconclusive and mostly based on studies from the early 2000s and earlier. STUDY DESIGN: Retrospective multicenter cohort study. SETTING & PARTICIPANTS: We searched the French national transplant database to identify all patients with renal AA amyloidosis who underwent kidney transplantation between 2008 and 2018. EXPOSURES: Age, cause of amyloidosis, use of biotherapies, and C-reactive protein levels. OUTCOMES: Outcomes were all-cause mortality and allograft loss. We also reported amyloidosis allograft recurrence, occurrence of acute rejection episodes, as well as infectious, cardiovascular, and neoplastic disease events. ANALYTICAL APPROACH: Kaplan-Meier estimator for mortality and cumulative incidence function method for allograft loss. Factors associated with patient and allograft survival were investigated using a Cox proportional hazards model and a cause-specific hazards model, respectively. RESULTS: 86 patients who received kidney transplants for AA amyloidosis at 26 French centers were included. The median age was 49.4 years (IQR, 39.7-61.1). The main cause of amyloidosis was familial Mediterranean fever (37 cases; 43%). 16 (18.6%) patients received biotherapy after transplantation. Patient survival rates were 94.0% (95% CI, 89.1-99.2) at 1 year and 85.5% (77.8-94.0) at 5 years after transplantation. Cumulative incidences of allograft loss were 10.5% (4.0-17.0) at 1 year and 13.0% (5.8-20.1) at 5 years after transplantation. Histologically proven AA amyloidosis recurrence occurred in 5 transplants (5.8%). An infection requiring hospitalization developed in 55.8% of cases, and there was a 27.9% incidence of acute allograft rejection. Multivariable analysis showed that C-reactive protein concentration at the time of transplantation was associated with patient survival (HR, 1.01; 95% CI, 1.00-1.02; P=0.01) and allograft survival (HR, 1.68; 95% CI, 1.10-2.57; P=0.02). LIMITATIONS: The study lacked a control group, and the effect of biotherapies on transplantation outcomes could not be explored. CONCLUSIONS: This relatively contemporary cohort of patients who received a kidney transplant for AA amyloidosis experienced favorable rates of survival and lower recurrence rates than previously reported. These data support the practice of treating these patients with kidney transplantation for end-stage kidney disease. PLAIN-LANGUAGE SUMMARY: AA amyloidosis is a severe and rare disease. Kidney involvement is frequent and leads to end-stage kidney disease. Because of the involvement of other organs, these patients are often frail, which has raised concerns about their suitability for kidney transplantation. We reviewed all patients with AA amyloidosis nephropathy who underwent kidney transplantation in France in the recent era (2008-2018) and found that the outcomes after kidney transplantation were favorable, with 85.5% of patients still alive 5 years after transplantation, a survival rate that is comparable to the outcomes of patients receiving a transplant for other forms of kidney diseases. Recurrence of amyloidosis in the transplanted kidney was infrequent (5.8%). These data support the practice of kidney transplantation for patients with AA amyloidosis who experience kidney failure.

A score for predicting colchicine resistance at the time of diagnosis in familial Mediterranean fever: data from the TURPAID registry.

OBJECTIVES: Colchicine forms the mainstay of treatment in FMF. Approximately 5-10% of FMF patients are colchicine resistant and require anti-IL-1 drugs. We aimed to compare the characteristics of colchicine-resistant and colchicine-responsive patients and to develop a score for predicting colchicine resistance at the time of FMF diagnosis. METHODS: FMF patients (0-18 years) enrolled in the Turkish Paediatric Autoinflammatory Diseases (TURPAID) registry were included. The predictive score for colchicine resistance was developed by using univariate/multivariate regression and receiver operating characteristics analyses. RESULTS: A total of 3445 FMF patients [256 (7.4%) colchicine-resistant and 3189 colchicine-responsive) were included (female:male ratio 1.02; median age at diagnosis 67.4 months). Colchicine-resistant patients had longer, more frequent attacks and were younger at symptom onset and diagnosis (P < 0.05). Fever, erysipelas-like erythema, arthralgia, arthritis, myalgia, abdominal pain, diarrhoea, chest pain, comorbidities, parental consanguinity and homozygosity/compound heterozygosity for exon 10 MEFV mutations were significantly more prevalent among colchicine-resistant than colchicine-responsive patients (P < 0.05). Multivariate logistic regression analysis in the training cohort (n = 2684) showed that age at symptom onset, attack frequency, arthritis, chest pain and having two exon 10 mutations were the strongest predictors of colchicine resistance. The score including these items had a sensitivity of 81.3% and a specificity of 49.1%. In the validation cohort (n = 671), its sensitivity was 93.5% and specificity was 53.8%. CONCLUSION: We developed a clinician-friendly and practical predictive score that could help us identify FMF patients with a greater risk of colchicine resistance and tailor disease management individually at the time of diagnosis.

Gut microbiota alterations are associated with phenotype and genotype in familial Mediterranean fever.

OBJECTIVE: FMF is the most common monogenic autoinflammatory disease associated with MEFV mutations. Disease phenotype and response to treatment vary from one patient to another, despite similar genotype, suggesting the role of environmental factors. The objective of this study was to analyse the gut microbiota of a large cohort of FMF patients in relation to disease characteristics. METHODS: The gut microbiotas of 119 FMF patients and 61 healthy controls were analysed using 16 s rRNA gene sequencing. Associations between bacterial taxa, clinical characteristics, and genotypes were evaluated using multivariable association with linear models (MaAslin2), adjusting on age, sex, genotype, presence of AA amyloidosis (n = 17), hepatopathy (n = 5), colchicine intake, colchicine resistance (n = 27), use of biotherapy (n = 10), CRP levels, and number of daily faeces. Bacterial network structures were also analysed. RESULTS: The gut microbiotas of FMF patients differ from those of controls in having increased pro-inflammatory bacteria, such as the Enterobacter, Klebsiella and Ruminococcus gnavus group. Disease characteristics and resistance to colchicine correlated with homozygous mutations and were associated with specific microbiota alteration. Colchicine treatment was associated with the expansion of anti-inflammatory taxa such as Faecalibacterium and Roseburia, while FMF severity was associated with expansion of the Ruminococcus gnavus group and Paracoccus. Colchicine-resistant patients exhibited an alteration of the bacterial network structure, with decreased intertaxa connectivity. CONCLUSION: The gut microbiota of FMF patients correlates with disease characteristics and severity, with an increase in pro-inflammatory taxa in the most severe patients. This suggests a specific role for the gut microbiota in shaping FMF outcomes and response to treatment.

Familial Mediterranean fever in patients with inflammatory bowel diseases: A nationwide study from the epi-IIRN.

BACKGROUND AND AIMS: Inflammatory Bowel Diseases (IBD) and Familial Mediterranean Fever (FMF) are auto-inflammatory diseases with common clinical and biological features. We aimed to determine their association and characterize the natural history in patients with both diagnoses. METHODS: Utilizing data from the epi-IIRN cohort, which includes 98% of Israel's population, we calculated the adjusted prevalence of FMF among IBD patients vs non-IBD controls. Case ascertainment of IBD was determined according to validated algorithms and for FMF by ICD-9 codes and colchicine purchase. RESULTS: In total, 34 375 IBD patients (56% Crohn's disease [CD] and 44% ulcerative colitis [UC]) were compared with 93 602 matched controls. Among IBD patients, 157 (0.5%) had FMF compared with 160 (0.2%) of non-IBD controls (OR = 2.68 [95%CI 2.2-3.3]; p< 0.001). Pediatric-onset IBD had a higher prevalence of FMF compared with adult-onset IBD (30/5,243 [0.6%] vs 127/29 132 [0.4%]), without statistical significanse (OR = 1.31 [0.88-1.96]; p= 0.2). FMF was more prevalent in CD (114/19 264 [0.6%]) than UC (43/15 111 [0.3%]; OR = 2.1 [1.5-3.0]), p< 0.001). FMF diagnosis preceded that of IBD in 130/157 cases (83%). FMF was associated with a more severe disease activity in UC patients at diagnosis, but not in CD patients. Outcomes were comparable between patients with CD+FMF vs CD alone; however in patients with UC+FMF, time to biologic treatment was shorter. CONCLUSION: FMF is more prevalent in IBD patients than in the general population, particularly in CD. The diagnosis of FMF precedes the diagnosis of IBD in most cases, and may be associated with a more severe course in UC.

Pyrin variant E148Q potentiates inflammasome activation and the effect of pathogenic mutations in cis.

OBJECTIVE: The p.E148Q variant in pyrin is present in different populations at a frequency of up to 29%, and has been associated with diseases, including vasculitis and FMF. The pathogenicity of p.E148Q in FMF is unclear, even when observed in cis or in trans to a single, typically recessive, pathogenic mutation. We performed functional validation to determine whether p.E148Q increases the ability of pyrin to form an active inflammasome complex in cell lines. METHODS: We interrogated the Australian Autoinflammatory Disease RegistrY (AADRY) to find candidate inheritance patterns for the p.E148Q variant in pyrin. Different pyrin variant combinations were tested in HEK293T cells stably expressing the adaptor protein apoptosis-associated speck-like (ASC), which were analysed by flow cytometry to visualize inflammasome formation, with and without stimulation by Clostridioides difficile toxin B (TcdB). Inflammasome-dependent cytokine secretion was also quantified by ELISA of supernatants from THP-1 cells transduced with lentiviral expression vectors. RESULTS: In AADRY, we observed the p.E148Q allele in individuals with autoinflammatory diseases alone or in conjunction with other pyrin variants. Two FMF families harboured the allele p.E148Q-M694I in cis with dominant heritability. In vitro, p.E148Q pyrin could spontaneously potentiate inflammasome formation, with increased IL-1ß and IL-18 secretion. p.E148Q in cis to classical FMF mutations provided significant potentiation of inflammasome formation. CONCLUSION: The p.E148Q variant in pyrin potentiates inflammasome activation in vitro. In cis, this effect is additive to known pathogenic FMF mutations. In some families, this increased effect could explain why FMF segregates as an apparently dominant disease.

Old paradigms and new concepts in familial Mediterranean fever (FMF): an update 2023.

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by recurrent attacks of fever and polyserositis. Its first description as a new entity was published by Siegal in 1945. Colchicine has been the treatment of choice for this disease since 1972. Significant progress has been made over the years in understanding FMF's clinical features, diagnosis, mode of inheritance, pathogenesis and therapeutic approach. However, many old paradigms related to FMF have proven inaccurate, leading to the emergence of new concepts that provide more precise insights. The term 'FMF' is no longer appropriate as the disease is found beyond the Mediterranean basin. The concept of diagnosis based only upon clinical ground proved to be wrong. The paradigm that MEFV mutations in FMF lead to loss of function of the encoded peptide pyrin turned out to be a gain of function mutation. Finally, the concept that as a genetic disease FMF should be treated for life was found to be inaccurate for the subpopulation of the heterozygote patients. Thus, the breakthroughs of identifying the gene associated with the disease (MEFV) and the deciphering of its pathogenesis revolutionized our old paradigms and replaced them with new and more precise insights.

Characteristics and course of patients with AA amyloidosis: single centre experience with 174 patients from Turkey.

OBJECTIVES: This study aimed to evaluate the clinical, laboratory and genetic characteristics and outcomes of patients with AA amyloidosis. METHODS: Patients followed up in a tertiary referral centre in Turkey with the diagnosis of inflammatory rheumatic diseases and immunohistologically proven AA amyloidosis were included in the study and retrospectively analysed. RESULTS: Among 184 patients with the diagnosis of AA amyloidosis, 174 (83 female, 91 male) were included in the analysis. The most common cause of AA amyloidosis was FMF (78.7%), and 91% of FMF-AA amyloidosis patients were carrying the p.M694V variant (74.1% homozygous). AA amyloidosis was identified earlier in patients with homozygous or compound heterozygous MEFV exon 10 variants compared with the heterozygous patients (27, 30 and 41 years, respectively). Patients with an estimated glomerular filtration rate <60 ml/min at admission had a higher frequency of progression to end-stage renal disease (P < 0.001). The overall mortality rate was 15.3% and it increased gradually in association with the amyloid burden (10% in patients with renal, 15% in renal + gastrointestinal and 43% in those with additional cardiac involvement). Renal findings responded completely to treatment in 31% of the patients, a partial response was observed in 4%, a stable course in 23.6% and progression in 38.5%. Amyloid storm was identified in nine patients and was found to be associated with increased mortality within 1 year. CONCLUSION: FMF patients still constitute the majority of AA amyloidosis patients in Turkey. The MEFV genotype and associated inflammatory load may affect the age of onset of AA amyloidosis, and earlier diagnosis and stricter follow-up and treatment may delay progression of the disease.

Efficacy and safety of anti-interleukin-1 treatment in familial Mediterranean fever patients: a systematic review and meta-analysis.

OBJECTIVES: FMF is the most common hereditary monogenic fever syndrome marked by recurrent attacks of fever and polyserositis. Colchicine is the current recommended first-line treatment for FMF. However, a small portion of FMF patients are unresponsive or intolerant to colchicine. Anti-IL-1 agents are alternative treatment options for colchicine-resistant or -intolerant FMF patients. This systematic review and meta-analysis aimed to provide qualitative and quantitative evidence for the efficacy and safety of anti-IL-1 agents in adult and paediatric FMF patients. METHODS: MEDLINE, EMBASE, CENTRAL and Web of Science were screened from inception to May 2023. We included adult and paediatric FMF patients who received continuous treatment with at least one of the anti-IL-1 drugs: anakinra, canakinumab and rilonacept. The primary efficacy outcome was the proportion of patients who achieved complete remission of attacks and the primary safety outcome was the proportion of patients who experienced at least one adverse event during treatment. A random-effects meta-analysis was performed for the quantitative synthesis. RESULTS: Fourty-four reports consisting of 1399 FMF patients were included. Sixty percent (95% CI 49%, 72%) of the adult patients and 81% (95% CI 72%, 89%) of the paediatric patients achieved complete remission. Anti-IL-1 agents significantly decreased levels of inflammatory markers. At least one adverse event was observed in 25% (95% CI 13%, 37%) of the adult patients and 12% (95% CI 3%, 21%) of the paediatric patients. CONCLUSION: Anti-IL-1 agents were effective and demonstrated a low adverse event profile in paediatric and adult FMF patients.

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.

Experimental models in Familial Mediterranean Fever (FMF): Insights into pathophysiology and therapeutic strategies.

Familial Mediterranean Fever (FMF) is a recurrent polyserositis characterized by self-limiting episodes or attacks of fever along with serosal inflammation. It mainly impacts people of the Mediterranean and Middle Eastern basin. FMF is a recessive autoinflammatory condition caused by mutation in the MEFV gene located on chromosome 16p13. MEFV mutations lead to the activation of the pyrin inflammasome resulting in an uncontrolled release of IL-1ß. Various in vitro, in vivo and ex vivo experimental models have been developed to further comprehend the etiology and pathogenesis of FMF. These models have been proven to be clinically relevant to human FMF and can provide significant information about biological systems with respect to this condition. Additionally, these models have provided pertinent contributions to the development of potent therapeutic strategies against FMF. In this review, we describe the different experimental models utilized in FMF and we focus primarily on the most widely used models that have produced prominent insights into the pathophysiology of the disease.

Validation of Fetal Medicine Foundation competing-risks model for small-for-gestational-age neonate in early third trimester.

OBJECTIVE: To evaluate the new 36-week Fetal Medicine Foundation (FMF) competing-risks model for the prediction of small-for-gestational age (SGA) at an earlier gestation of 30 + 0 to 34 + 0 weeks. METHODS: This was a retrospective multicenter cohort study of prospectively collected data on 3012 women with a singleton pregnancy undergoing ultrasound examination at 30 + 0 to 34 + 0 weeks' gestation as part of a universal screening program. We used the default FMF competing-risks model for prediction of SGA at 36 weeks' gestation combining maternal factors (age, obstetric and medical history, weight, height, smoking status, race, mode of conception), estimated fetal weight (EFW) and uterine artery pulsatility index (UtA-PI) to calculate risks for different cut-offs of birth-weight percentile and gestational age at delivery. We examined the accuracy of the model by means of discrimination and calibration. RESULTS: The prediction of SGA < 3rd percentile improved with the addition of UtA-PI and with a shorter examination-to-delivery interval. For a 10% false-positive rate, maternal factors, EFW and UtA-PI predicted 88.0%, 74.4% and 72.8% of SGA < 3rd percentile delivered at < 37, < 40 and < 42 weeks' gestation, respectively. The respective values for SGA < 10th percentile were 86.1%, 69.3% and 66.2%. In terms of population stratification, if the biomarkers used are EFW and UtA-PI and the aim is to detect 90% of SGA < 10th percentile, then 10.8% of the population should be scanned within 2 weeks after the initial assessment, an additional 7.2% (total screen-positive rate (SPR), 18.0%) should be scanned within 2-4 weeks after the initial assessment and an additional 11.7% (total SPR, 29.7%) should be examined within 4-6 weeks after the initial assessment. The new model was well calibrated. CONCLUSIONS: The 36-week FMF competing-risks model for SGA is also applicable and accurate at 30 + 0 to 34 + 0 weeks and provides effective risk stratification, especially for cases leading to delivery < 37 weeks of gestation. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Evaluation of screening performance of first-trimester competing-risks prediction model for small-for-gestational age in Asian population.

OBJECTIVE: To examine the external validity of the Fetal Medicine Foundation (FMF) competing-risks model for the prediction of small-for-gestational age (SGA) at 11-14 weeks' gestation in an Asian population. METHODS: This was a secondary analysis of a multicenter prospective cohort study in 10 120 women with a singleton pregnancy undergoing routine assessment at 11-14 weeks' gestation. We applied the FMF competing-risks model for the first-trimester prediction of SGA, combining maternal characteristics and medical history with measurements of mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI) and serum placental growth factor (PlGF) concentration. We calculated risks for different cut-offs of birth-weight percentile (< 10th , < 5th or < 3rd percentile) and gestational age at delivery (< 37 weeks (preterm SGA) or SGA at any gestational age). Predictive performance was examined in terms of discrimination and calibration. RESULTS: The predictive performance of the competing-risks model for SGA was similar to that reported in the original FMF study. Specifically, the combination of maternal factors with MAP, UtA-PI and PlGF yielded the best performance for the prediction of preterm SGA with birth weight < 10th percentile (SGA < 10th ) and preterm SGA with birth weight < 5th percentile (SGA < 5th ), with areas under the receiver-operating-characteristics curve (AUCs) of 0.765 (95% CI, 0.720-0.809) and 0.789 (95% CI, 0.736-0.841), respectively. Combining maternal factors with MAP and PlGF yielded the best model for predicting preterm SGA with birth weight < 3rd percentile (SGA < 3rd ) (AUC, 0.797 (95% CI, 0.744-0.850)). After excluding cases with pre-eclampsia, the combination of maternal factors with MAP, UtA-PI and PlGF yielded the best performance for the prediction of preterm SGA < 10th and preterm SGA < 5th , with AUCs of 0.743 (95% CI, 0.691-0.795) and 0.762 (95% CI, 0.700-0.824), respectively. However, the best model for predicting preterm SGA < 3rd without pre-eclampsia was the combination of maternal factors and PlGF (AUC, 0.786 (95% CI, 0.723-0.849)). The FMF competing-risks model including maternal factors, MAP, UtA-PI and PlGF achieved detection rates of 42.2%, 47.3% and 48.1%, at a fixed false-positive rate of 10%, for the prediction of preterm SGA < 10th , preterm SGA < 5th and preterm SGA < 3rd , respectively. The calibration of the model was satisfactory. CONCLUSION: The screening performance of the FMF first-trimester competing-risks model for SGA in a large, independent cohort of Asian women is comparable with that reported in the original FMF study in a mixed European population. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

E148Q variant: a familial Mediterranean fever-causing mutation or a sequence variant?

Familial Mediterranean fever (FMF) is an autosomal recessive autoinflammatory disease, linked to mutations in the MEFV gene. The p.E148Q variant, found on exon 2, has an uncertain role in FMF, with debates on whether it is a benign polymorphism or a pathogenic mutation. This study aimed to assess the clinical characteristics and severity of FMF in patients homozygous for the p.E148Q variant and to evaluate the impact of the p.V726A variant in these patients. This retrospective cohort study analyzed data from electronic medical records at Carmel Medical Center, Israel. Patients who underwent genetic testing for FMF from November 2004 to December 2019 and had p.E148Q/p.E148Q or p.E148Q/p.E148Q + p.V726A variants were included. Disease severity was assessed using the Tel Hashomer Key to Severity Score. Statistical analyses compared clinical characteristics and severity between genotype groups. The study included 61 FMF patients, with 24 (39%) having p.E148Q/p.E148Q and 37 (61%) having p.E148Q/p.E148Q + p.V726A variants. The majority (72%) were Druze. Most patients (65.5%) exhibited mild disease, while 31.1% had moderate disease, with no cases of severe disease. Colchicine treatment significantly reduced CRP levels in all patients. CONCLUSION: These findings suggest that the p.E148Q variant, whether alone or with p.V726A, generally results in mild to moderate FMF severity, supporting its pathogenic role in particular ethnicity. These results contribute to understanding the clinical significance of the p.E148Q variant and considering the patient's need for Colchicine treatment. WHAT IS KNOWN: • The role of the p.E148Q variant in FMF is debated, with questions about whether it is a benign polymorphism or a pathogenic mutation. • The prevalence of MEFV variants can vary significantly among different ethnic groups. WHAT IS NEW: • The p.E148Q variant has clinical significance in particular ethnicities, as supported by a significant reduction in CRP levels following colchicine treatment. • The p.E148Q variant, whether alone or with p.V726A, generally results in mild to moderate FMF severity.

Complex regulation of alarmins S100A8/A9 and secretion via gasdermin D pores exacerbates autoinflammation in familial Mediterranean fever.

BACKGROUND: Familial Mediterranean fever (FMF), caused by mutations in the pyrin-encoding MEFV gene, is characterized by uncontrolled caspase-1 activation and IL-1ß secretion. A similar mechanism drives inflammation in cryopyrin-associated periodic fever syndrome (CAPS) caused by mutations in NLRP3. CAPS and FMF, however, result in largely different clinical manifestations, pointing to additional, autoinflammatory pathways involved in FMF. Another hallmark of FMF is extraordinarily high expression of S100A8 and S100A9. These alarmins are ligands of Toll-like receptor 4 and amplifiers of inflammation. However, the relevance of this inflammatory pathway for the pathogenesis of FMF is unknown. OBJECTIVE: This study investigated whether mutations in pyrin result in specific secretion of S100A8/A9 alarmins through gasdermin D pores' amplifying FMF pathology. METHODS: S100A8/A9 levels in FMF patients were quantified by enzyme-linked immunosorbent assay. In vitro models with knockout cell lines and specific protein inhibitors were used to unravel the S100A8/A9 secretion mechanism. The impact of S100A8/A9 to the pathophysiology of FMF was analyzed with FMF (MEFVV726A/V726A) and S100A9-/- mouse models. Pyrin-S100A8/A9 interaction was investigated by coimmunoprecipitation, immunofluorescence, and enzyme-linked immunosorbent assay studies. RESULTS: The S100A8/A9 complexes directly interacted with pyrin. Knocking out pyrin, caspase-1, or gasdermin D inhibited the secretion of these S100 alarmins. Inflammatory S100A8/A9 dimers were inactivated by tetramer formation. Blocking this inactivation by targeted S100A9 deletion in a murine FMF model demonstrated the relevance of this novel autoinflammatory pathway in FMF. CONCLUSION: This is the first proof that members of the S100 alarmin family are released in a pyrin/caspase-1/gasdermin D-dependent pathway and directly drive autoinflammation in vivo.

Recent Insights in Pyrin Inflammasome Activation: Identifying Potential Novel Therapeutic Approaches in Pyrin-Associated Autoinflammatory Syndromes.

Pyrin is a cytosolic protein encoded by the MEFV gene, predominantly expressed in innate immune cells. Upon activation, it forms an inflammasome, a multimolecular complex that enables the activation and secretion of IL-1ß and IL-18. In addition, the Pyrin inflammasome activates Gasdermin D leading to pyroptosis, a highly pro-inflammatory cell death. Four autoinflammatory syndromes are associated with Pyrin inflammasome dysregulation: familial Mediterranean fever, hyper IgD syndrome/mevalonate kinase deficiency, pyrin-associated autoinflammation with neutrophilic dermatosis, and pyogenic arthritis, pyoderma gangrenosum, and acne syndrome. In this review, we discuss recent advances in understanding the molecular mechanisms regulating the two-step model of Pyrin inflammasome activation. Based on these insights, we discuss current pharmacological options and identify a series of existing molecules with therapeutic potential for the treatment of pyrin-associated autoinflammatory syndromes.

Feasibility of canakinumab withdrawal in colchicine-resistant familial Mediterranean fever.

OBJECTIVES: There is no consensus on canakinumab treatment tapering and discontinuation strategies in colchicine-resistant FMF patients. In this study, we aimed to establish a treatment management and discontinuation protocol in paediatric FMF patients treated with canakinumab. METHODS: Fifty-eight FMF patients treated with canakinumab were included. Since 2020, we have applied a protocol based on our experience whereby canakinumab is administered monthly in the first 6 months, followed by bimonthly for 6 months, and a final period of every 3 months (for 6 months). The patients were divided into two groups: 2012-2019 (group A) and 2020-2022 (group B). RESULTS: In group A (n = 33), the median duration of canakinumab treatment was 2.5 years [interquartile range (IQR) 1.9-3.7]. A total of 25 of 33 patients discontinued canakinumab after a median of 2.1 years (IQR 1.8-3.4). In two patients, canakinumab was restarted because of relapse. In group B (n = 25), canakinumab was discontinued in 18 patients at the end of 18 months. After a median follow-up of 0.8 years (IQR 0.6-1.1), two patients had a relapse and canakinumab treatment was reinitiated. The remaining 16 patients still have clinically inactive disease and are receiving only colchicine. When we compared the characteristics between groups A and B, there were no significant differences regarding demographics, clinical features, and outcomes. CONCLUSION: This is the largest study in the literature suggesting a protocol for discontinuing canakinumab in paediatric FMF patients. It was possible to discontinue canakinumab successfully in more than half of the patients in 18 months. Thus we suggest that this protocol can be used in paediatric FMF patients.

Increased risk for stroke in patients with familial Mediterranean fever: results from a large population-based study.

OBJECTIVE: The association between chronic inflammatory conditions and cardiovascular disease is well established. Considering FMF, few studies exist investigating the risk of ischaemic heart disease, and none address the risk of stroke. We aimed to evaluate the incidence and risk for stroke in FMF patients compared with the general population. METHODS: A retrospective cohort study using the electronic database of Clalit Health Services (CHS), the largest health organization in Israel. All FMF patients diagnosed between 2000 and 2016 were included and matched with control according to age, gender and place of residence. Follow-up continued until the first diagnosis of stroke or death. The incidence of stroke was compared between the groups using univariate and multivariate models adjusting for cardiovascular risk-factors. RESULTS: A total of 9769 FMF patients and a similar number of controls were followed up for a median period of 12.5 years. The mean age at the beginning of the follow-up was 25.7 years. In total, 208 FMF patients were diagnosed with stroke compared with 148 controls, resulting in an incidence rate (per 10 000 persons-years) of 19.8 (95% CI 17.2, 22.7) and 13.9 (95% CI 11.8, 16.4), respectively, and a crude HR of 1.42 (95% CI 1.15-1.76; P < 0.001). In a multivariate analysis, FMF patients who developed amyloidosis with related or non-related renal failure demonstrated significant stroke risk (HR = 2.16; 95% CI 1.38, 3.38; P < 0.001), as well as for those who did not develop these complications (HR = 1.32; 95% CI 1.04, 1.67; P < 0.05). CONCLUSION: FMF patients are at increased risk for stroke regardless of known complications.

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.

Long-term results of kidney transplantation in patients with familial mediterranean fever.

INTRODUCTION: Long-term kidney transplantation (KT) results in patients with familial Mediterranean fever (FMF)-related amyloidosis are not well studied. This study reviewed the long-term survival outcomes of FMF patients who underwent KT. METHODS: We compared the outcomes of 31 patients who underwent (KT) for biopsy-proven amyloidosis secondary to FMF with 31 control patients (five with diabetes mellitus and 26 with nondiabetic kidney disease) undergoing KT between 1994 and 2021 at Baskent University Hospital. All data were recorded retrospectively from patients' files. RESULTS: THE MEDIAN AGE (QUARTILE DEVIATION: QD) at the time of KT in the FMF and control group were 31 (6.7) and 33 (11), respectively. The median follow-up period (QD) after KT was 108 (57) months in the FMF and 132 (72) months in the control group. In the FMF group, graft and patient survivals were 71% and 84% at 5 years and 45% and 48% at 10 years, respectively. In the control group, graft and patient survivals were 79% and 100% at 5 years and 63% and 71% at 10 years, respectively. Patient survival in the FMF group at 5 years was significantly lower than in the control group (p = .045). There was no statistically significant difference between the FMF and control groups in terms of graft and patient survival, and serum creatinine levels at 10 years. All patients were given triple immunosuppressive treatment with cyclosporine, mycophenolate mofetil, and prednisolone. Three patients received anakinra and one received canakinumab in addition to colchicine treatment. One FMF patient also underwent heart transplantation due to AA amyloidosis. Of the FMF patients, 11 died during follow-up. CONCLUSION: We have found that the long-term outcome of KT in patients with FMF amyloidosis is numerically worse but not statistically different from the control group. However, short- and long-term complications still need to be resolved.