Clinical and subclinical inflammation in patients with familial Mediterranean fever and in heterozygous carriers of MEFV mutations

Clinical Associations of E148Q Heterozygosity: What to Expect From E148Q?

OBJECTIVE

The exact effects of MEFV variants on inflammation are still under investigation, and reports on variants of unknown significance, particularly the E148Q variant, have been conflicting. Therefore, this study aims to investigate patients exhibiting E148Q heterozygosity, focusing on diagnoses and disease courses to assist physicians in interpreting the variant.

METHODS

Data of pediatric patients presenting to the Pediatric Rheumatology clinic between November 2016 and September 2023, exhibiting only E148Q heterozygosity in MEFV gene analysis, were extracted. Patients who were lost before 9 months of follow-up have been excluded to ensure the completion of initial diagnostic tests and evaluations.

RESULTS

Among the 119 patients with E148Q variant, the diagnoses were as follows: healthy, 51.3%; IgA vasculitis, 10.1%; Familial Mediterranean Fever (FMF), 7.6%; Periodic fever, Aphtous stomatitis, Pharyngitis, Adenitis (PFAPA), 6.7%; and other diagnoses, 19.3%. IgA vasculitis patients experienced articular, gastrointestinal, and renal involvement at rates of 91.7%, 58.3%, and 16.7%, respectively. Complete response, partial response, and no response to colchicine were 37.5%, 12.5%, and 50%, respectively, in PFAPA patients. All FMF patients responded to colchicine treatment resulting in reduced mean FMF episode counts in 6 months from 3.22 ± 0.92 to 0.56 ± 0.52.

CONCLUSIONS

The E148Q variant may amplify inflammation and modify disease courses. Patients with the E148Q variant experiencing typical FMF episodes should receive colchicine, but clinicians should exercise caution regarding alternative diagnoses. Additionally, the E148Q variant may increase acute phase reactants and disease severity in IgA vasculitis. However, to reach definitive conclusions on its treatment-modifying role in PFAPA, universal diagnosis and treatment response criteria should be adopted.

Role of serum calprotectin in identifying familial Mediterranean fever attacks

BACKGROUND/AIM

The aim of the study was to evaluate serum calprotectin (CLP) levels in familial Mediterranean fever (FMF) patients and to investigate the utility of CLP in distinguishing patients with attack from patients without attack.

MATERIAL AND METHOD

FMF patients, rheumatoid arthritis (RA) patients, and healthy controls were included. Serum calprotectin levels were quantified utilizing the enzyme-linked immunosorbent assay (ELISA) method. Receiver operating characteristic (ROC) curve analysis was used to identify the cut-off value of serum CLP level to differentiate FMF patients with attack from those without. Logistic regression analysis was performed to identify predictors.

RESULTS

Significant differences were observed among the three groups concerning white blood cell (WBC), neutrophil, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum CLP levels (p = 0.003, p = 0.004, p < 0.001, p < 0.001, and p = 0.002, respectively). Higher ESR, CRP, and serum CLP levels were observed in FMF patients with attacks than those without (all, p < 0.001). Serum CLP was significantly higher in RA patients than in FMF patients in remission (p < 0.001). ROC analysis identified a threshold CLP concentration in FMF with an attack to be 47.1 pg/mL (83.3% sensitivity, 60.6% specificity, AUC = 0.74, 95% CI = 0.63-0.85, p < 0.001). In univariate logistic regression analysis, CLP (β = 1.045, 95% CI = 1.017-1.073, p = 0.001) was predictive of FMF patients experiencing an attack.

CONCLUSION

Serum CLP proves to be as productive as ESR in illustrating inflammation and demonstrating the existence of attacks in FMF patients.

Increased risk of osteoporosis and femoral neck fractures in patients with familial Mediterranean fever-a large retrospective cohort study

OBJECTIVES

The direct impact of inflammatory conditions and their therapy with corticosteroids contribute to an increased risk of osteoporosis with associated fractures. Familial Mediterranean fever (FMF) is an autoinflammatory disorder not commonly treated with corticosteroids. Evidence regarding FMF association with osteoporosis and femur fractures is anecdotal. We aimed to evaluate the incidence and risk of osteoporosis and femoral neck fracture in FMF patients compared with the general population.

METHODS

A retrospective cohort study using the electronic database of Clalit Health Services of all FMF patients first diagnosed between 2000 and 2016 and controls was conducted including age- and sex-matched controls in a 1:1 ratio. Follow-up continued until the first diagnosis of osteoporosis or fracture. Risk for these conditions was compared using univariate and multivariate Cox regression models.

RESULTS

A total of 9769 FMF patients were followed for a median period of 12.5 years. Of these, 304 FMF patients were diagnosed with osteoporosis compared with 191 controls, resulting in an incidence rate (per 10 000 persons-years) of 28.8 and 17.8, respectively, and a crude hazard ratio of 1.62 (95% CI 1.35, 1.93; P < 0.001). Patients were diagnosed with osteoporosis at a considerably younger age than controls [60.1 (s.d. 12.4) vs 62.5 (s.d. 11.0) years; P = 0.028]. A total of 56 FMF patients were diagnosed with femoral neck fracture compared with 35 controls, resulting in an incidence rate of 5.3 and 3.3, respectively, and a crude HR of 1.60 (95% CI 1.05, 2.44; P < 0.05).

CONCLUSION

FMF patients are at increased risk for osteoporosis and consequently femur fracture. Our findings emphasize the importance of considering bone health in the management of FMF patients.

[Coexistence of familial Mediterranean fever and seronegative spondyloarthritis: peculiarities of the course]

Familial Mediterranean fever (FMF) is an autosomal recessive disease distributed among populations of Mediterranean origin - Armenians, Sephardi Jews, Arabs, Turks. There are numerous clinical observations regarding combination of FMF, as a classical representative of autoinflammatory diseases, with systemic diseases of connective tissue. Seronegative spondyloarthritis (SpA) are the most interesting disorders from this point of view, as far as sacroiliitis - an essential feature of SpA, may also present as a part of joint syndrome in FMF. The main objective of this clinical study was the investigation of the peculiarities of courses of FMF and SpA in case of their coexistence. We studied 126 patients with FMF, SpA and coexistence of both. According to results, patients with the overlap of FMF with SpA had relatively milder course of disease in comparison with each disease separately. Comparative clinical and instrumental characteristics of FMF-associated disorders had shown that in FMF-SpA overlap the symptoms of both diseases are less severe.

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-1β 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.

The pyrin inflammasome, a leading actor in pediatric autoinflammatory diseases

The activation of the pyrin inflammasome represents a highly intriguing mechanism employed by the innate immune system to effectively counteract pathogenic agents. Despite its key role in innate immunity, pyrin has also garnered significant attention due to its association with a range of autoinflammatory diseases (AIDs) including familial Mediterranean fever caused by disruption of the MEFV gene, or in other genes involved in its complex regulation mechanisms. Pyrin activation is strictly dependent on homeostasis-altering molecular processes, mostly consisting of the disruption of the small Ras Homolog Family Member A (RhoA) GTPases by pathogen toxins. The downstream pathways are regulated by the phosphorylation of specific pyrin residues by the kinases PKN1/2 and the binding of the chaperone 14-3-3. Furthermore, a key role in pyrin activation is played by the cytoskeleton and gasdermin D, which is responsible for membrane pores in the context of pyroptosis. In addition, recent evidence has highlighted the role of steroid hormone catabolites and alarmins S100A8/A9 and S100A12 in pyrin-dependent inflammation. The aim of this article is to offer a comprehensive overview of the most recent evidence on the pyrin inflammasome and its molecular pathways to better understand the pathogenesis behind the significant group of pyrin-related AIDs.

Inflammatory comorbidities ın the largest pediatric Familial Mediterranean fever cohort: a multicenter retrospective study of Pediatric Rheumatology Academy (PeRA)-Research Group (RG)

AIM

The aim of this study was to investigate the frequency and type of FMF-associated inflammatory diseases in a large FMF pediatric patients and to compare them to those FMF patients without concomitant inflammatory diseases.

MATERIALS AND METHODS

Familial Mediterranean fever patients enrolled in the Pediatric Rheumatology Academy (PeRA)-Research Group (RG) were included. The patients were divided into two groups according to concomitant inflammatory disease as FMF patients who had a concomitant inflammatory disease (group 1) and FMF patients who did not have a concomitant inflammatory disease (group 1). The clinical findings and treatments were compared between the two groups.

RESULTS

The study group comprised 3475 patients with FMF. There were 294 patients (8.5%) in group 1 and 3181 patients (91.5%) in group 2. Juvenile idiopathic arthritis (n = 136) was the most common accompanying inflammatory disease. Arthritis, M694V homozygosity, and the need for biological therapy were more frequently observed in Group 1 (p < 0.05). Fever and abdominal pain were more frequently detected in Group 2 (p < 0.05). FMF patients with concomitant inflammatory diseas more frequently demonstrated colchicine resistance. There were no significant differences in the median attack frequency, chest pain, amyloidosis, erysipelas-like erythema, or family history of FMF between the two patient groups.

CONCLUSION

To the best of our knowledge, this is the largest pediatric cohort reviewed to date. FMF patients may have different clinical profiles and colchicine responses if they have with concomitant inflammatory diseases. Key points • FMF is associated with some inflammatory comorbidities diseases. • To the best of our knowledge, this is the largest cohort evlauated pediatric FMF associated inflammatory comorbidities diseases reviewed to date.

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-1β 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.

Osteopontin as an early predictor of atherosclerosis in attack-free Familial Mediterranean fever patients

Familial Mediterranean fever (FMF) is an autoinflammatory disease that is associated with endothelial dysfunction and atherosclerosis. Osteopontin which is a multifunctional protein involved in the modulation of inflammatory processes may contribute to the development of atherosclerosis in FMF patients. Therefore, this cross-sectional study investigated the relationship of osteopontin with carotid intima media thickness (CIMT) and atherogenic indices in patients with FMF. Serum osteopontin levels, CIMT, Castelli risk index I and II, plasma atherogenic index (PAI), non - high-density lipoprotein cholesterol, and atherogenic coefficient (AC) in 64 attack-free FMF patients were compared with levels in 23 healthy control subjects. The serum osteopontin level, CIMT, Castelli risk index I, AC and PAI were significantly higher, and high-density lipoprotein cholesterol was significantly lower in FMF patients (P < .001, P < .001, P = .045, P = .016, P = .045, and P = .024; respectively). There were significant positive correlations between osteopontin and CIMT, PAI, AC, and Castelli risk index I (R = 0.580, R = 0.259, R = 0.233, R = 0.277; respectively) and there was significant negative correlation between osteopontin and high-density lipoprotein cholesterol (r= -0.309). Patients who had homozygote mutations had significantly higher osteopontin, PAI, Castelli risk index I and II level. The current study is the first to demonstrate significantly increased serum osteopontin levels in attack-free FMF patients compared with healthy controls. It was also associated with CIMT and many atherogenic indices. This finding provides a new experimental basis to understand the pathogenesis of inflammation-induced atherosclerosis in FMF patients. Furthermore, patients who had homozygote mutations had worse atherogenic indices than those with heterozygote mutations.

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.

Comparison of posterior segment ocular parameters of Familial mediterranean fever with homozygous M694V mutation and carriers with heterozygous M694V mutation in children

PURPOSE

The aim of this study is to comparatively evaluate the posterior segment ocular parameters of Familial Mediterranean fever (FMF) patients, asymptomatic FMF carriers, and the healthy controls in the pediatric age group.

METHODS

The study included 30 FMF patients with homozygous M694V mutation in remission under colchicine therapy, 12 asymptomatic FMF carriers with heterozygous M694V mutation, and 41 age-sex-matched healthy controls. All patients underwent detailed eye examination, and peripapillary retinal nerve fiber layer (pRNFL) thickness, central macular thickness (CMT), subfoveal choroidal thickness (SCT), macular vascular densities, and foveal avascular zone (FAZ) areas were measured using swept-source optical coherence tomography angiography.

RESULTS

In this study, the mean pRNFL thickness was statistically significantly thinner (p = 0.010) in the FMF patients group compared to the FMF carriers group and the healthy control group, especially in the inferior quadrant of pRNFL (p = 0.042). The CMT in asymptomatic FMF carriers group was statistically significantly thicker than in FMF patients group (p = 0.037), especially the superior and inferior quadrants of macula were affected (p = 0.024; p = 0.020, respectively). In addition, this study showed that the changes of pRNFL thickness and CMT in pediatric patients with FMF were moderately correlated with the duration of diagnosis. There was no significant difference between the groups in terms of macular vascular densities and FAZ values.

CONCLUSION

FMF is a hereditary autoinflammatory disease that causes multi-organ involvement, and this study showed that posterior segment ocular parameters could be affected not only in FMF patients but also in asymptomatic FMF carriers.

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.

An Update on Familial Mediterranean Fever

(1) Background: Familial Mediterranean Fever (FMF) is the prototypal autoinflammatory disease, characterized by recurrent bursts of neutrophilic inflammation. (2) Methods: In this study we look at the most recent literature on this condition and integrate it with novel information on treatment resistance and compliance. (3) Results: The canonical clinical presentation of FMF is in children with self-limited episodes of fever and polyserositis, associated with severe long-term complications, such as renal amyloidosis. It has been described anecdotally since ancient times, however only recently it has been characterized more accurately. We propose an updated overview on the main aspects of pathophysiology, genetics, diagnosis and treatment of this intriguing disease. (4) Conclusions: Overall, this review presents the all the main aspects, including real life outcome of the latest recommendation on treatment resistance of FMF, a disease, that not only helped understanding the pathophysiology of the auto inflammatory process but also the functioning of the innate immune system itself.

Renal involvement in monogenic autoinflammatory diseases: A narrative review

Autoinflammatory diseases (AIDs) are mostly caused by dysfunctions in single genes encoding for proteins with a prominent role in the regulation of innate immunity, such as complement factors, inflammasome components, tumour necrosis factor (TNF)-α, and proteins belonging to type I-interferon (IFN) signalling pathways. Due to the deposition of amyloid A (AA) fibrils in the glomeruli, unprovoked inflammation in AIDs frequently affects renal health. In fact, secondary AA amyloidosis is the most common form of amyloidosis in children. It is caused by the extracellular deposition of fibrillar low-molecular weight protein subunits resulting from the degradation and accumulation of serum amyloid A (SAA) in numerous tissues and organs, primarily the kidneys. The molecular mechanisms underlying AA amyloidosis in AIDs are the elevated levels of SAA, produced by the liver in response to pro-inflammatory cytokines, and a genetic predisposition due to specific SAA isoforms. Despite the prevalence of amyloid kidney disease, non-amyloid kidney diseases may also be responsible for chronic renal damage in children with AIDs, albeit with distinct characteristics. Glomerular damage can result in various forms of glomerulonephritis with distinct histologic characteristics and a different underlying pathophysiology. This review aims to describe the potential renal implications in patients with inflammasomopathies, type-I interferonopathies, and other rare AIDs in an effort to improve the clinical course and quality of life in paediatric patients with renal involvement.

Fetal thymic-thoracic ratio in pregnancies with familial Mediterranean fever

OBJECTIVE

To investigate the thymic-thoracic ratio (TTR) in fetuses of pregnant women with familial Mediterranean fever (FMF).

STUDY DESIGN

This prospective case-control study was conducted with 43 pregnant women diagnosed with FMF and 43 gestational age-matched healthy controls. Pregnant women between 28 and 40 weeks who applied for antenatal care were included in the study. Healthy pregnant women whose age and gestational week matched were defined as the control group.

RESULTS

TTR was significantly lower in the FMF group compared to the control group. The mean TTR value was 0.34 ± 0.03 in the FMF group and 0.36 ± 0.02 in the control group (p < 0.001). TTR was significantly lower in those with FMF duration of ten years or more than those with FMF of less than ten years (p < 0.001). In addition, pregnant women who had an attack during pregnancy had lower TTR (p < 0.001). TTR was significantly associated with white blood cell count, neutrophil count, monocyte count, platelet count, mean platelet volume, C-reactive protein, red cell distribution width, and platelet‑to‑lymphocyte ratio.

CONCLUSION

Besides the inflammation during the FMF attacks, the ongoing subclinical inflammation between the attacks might affect the fetal thymus size. Since TTR is an easily applicable method, it can be used to evaluate fetal inflammation.

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.

Evaluation of Cardiac Arrhythmia Susceptibility in Pediatric Familial Mediterranean Fever Patients

Aim: Familial Mediterranean fever is an autoinflammatory disease characterized by attacks of inflammation. Despite treatment, there is evidence of subclinical persistence of inflammation with normal laboratory values. This study was conducted to investigate the cardiac effects of continued subclinical inflammation in children and the predisposition towards arrhythmia in familial Mediterranean fever. Materials and Methods: Age and sex-matched familial Mediterranean fever patients and healthy controls were compared in terms of demographic, laboratory, echocardiographic and electrocardiographic data. The patients with familial Mediterranean fever were grouped according to disease severity scores and compared in terms of electrocardiographic data that could indicate arrhythmogenesis. Correlation analysis was used to examine the relationship between the electrocardiographic measurements and the clinical and laboratory data. Results: In the comparison of the two groups, no significant difference was found in the echocardiographic measurements in terms of left ventricular systolic and diastolic functions. According to these data, QT and Tp-e intervals were significantly longer in those with familial Mediterranean fever (p=0.002, p=0.046, respectively). When the patients were classified according to the 3 separate disease severity scores, QT dispersion in the moderate-severe disease group was significantly longer than in the mild disease group (p

The relation between C-reactive protein and serum amyloid A in patients with autoinflammatory diseases

BACKGROUND

Autoinflammatory diseases are rare disorders of the innate immune system characterized by fever and other signs of inflammation. A feared complication of autoinflammatory diseases is the development of AA amyloidosis. AA amyloidosis is caused by extracellular deposition of soluble serum amyloid A (SAA) proteins as insoluble amyloid fibrils leading to organ damage. Prolonged high levels of SAA are a prerequisite to develop AA amyloidosis. Since measurement of SAA is relatively expensive and sometimes unavailable, C-reactive protein (CRP) is often used as a surrogacy marker to test for inflammation.

OBJECTIVE

The aim of this research is to evaluate the possible relation between CRP and SAA.

METHODS

A retrospective cohort of patients with autoinflammatory diseases (n = 99) where SAA and CRP blood testing was performed in the period between 2015 and 2021 in the University Medical Centre in Groningen was used to investigate the correlation between CRP and SAA.

RESULTS

CRP and SAA have a high correlation (rho = 0.755, p < 0.001). A CRP value below 0.45 mg/L results in 100% sensitivity for SAA below 4 mg/L. CRP below 5 mg/L is a good predictor of SAA below 4 mg/L with 85.4% sensitivity and 83.6% specificity. Only prednisone and erythrocyte sedimentation rate (ESR) significantly influence the relation between CRP and log₁₀SAA.

CONCLUSION

There was a significant correlation between CRP and SAA in our retrospective cohort. CRP levels below 5 mg/L proved to be highly predictive of SAA levels below 4 mg/L. This may not be true for patients on steroids.

The correlation of plasma atherogenic index and obesity in patients with familial Mediterranean fever

BACKGROUND

The plasma atherogenic index (PAI) is associated with cardiovascular diseases. This study evaluated the relationship between PAI and obesity in patients with familial Mediterranean fever (FMF) and its advantage over conventional lipid components in predicting obesity.

METHODS

The cross-sectional study included 164 FMF patients in the attack-free period and a control group of 160 healthy individuals. Serum lipid components were measured, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C). PAI was calculated as log 10 (TG/HDL-C). The relationship between PAI, four conventional lipid profiles, and obesity was evaluated.

RESULTS

The mean PAI values (p = 0.003), frequency of obesity (p = 0.005), TC (p = 0.008), TG (p = 0.000), and LDL-C (p = 0.005) values were determined to be statistically significantly higher in the FMF patients than in the control group. The FMF patients with a higher PAI value had a higher risk of obesity, systolic and diastolic blood pressure, TC, and LDL-C, and lower HDL-C (p < 0.001). The Pearson coefficient for PAI (r = 0.854; p < 0.001) was calculated as an explanatory percentage on the variable of obesity of r² = 0.730. There was a stronger relationship between obesity and PAI than conventional lipid components (p < 0.001).

CONCLUSION

We have found that the PAI, BMI, TC, TG, and LDL-C values of the FMF patients were determined to be higher. The higher PAI was strongly correlated to obesity in FMF patients. The first time in FMF patients, PAI showed increased sensitivity to predict obesity, higher than conventional lipid components. It can be a promising biomarker for obesity compared to other lipid components. A low-cost and readily available index derived from routine (TG and HDL-C) tests are advantages in identifying obesity in FMF patients. Key Points • The PAI is valuable for atherosclerotic CVD risk management in patients with rheumatismal diseases. • A correlation is found between PAI level and obesity, and it is used as a biomarker for obesity in the healthy population. • The PAI revealed increased sensitivity to predict obesity, higher than conventional lipid components in FMF patients.

Periodic Fever in Children: Etiology and Diagnostic Challenges

Periodic fever in children is an autoinflammatory illness with an unknown cause. Symptoms include frequent episodes of fever that are followed by an increase in inflammatory markers. A genetic background for periodic fever of unknown origin has been hypothesized, based on its family clustering and parallels to other autoinflammatory illnesses such as familial Mediterranean fever. Genome analysis has been used in studies to look for related gene variations in periodic fever of unknown origin in the pediatric population. 

Children with periodic fevers might be a diagnostic challenge. After ruling out the most prevalent causes, a wide variety of other possibilities are investigated. Infectious and noninfectious causes of periodic fever in children are discussed in this article.

Inflammasomes (intracellular proteins that activate interleukin (IL)-1b and IL-18) and genetic/hereditary variations are thought to be implicated in the pathogenesis of periodic fever. Evaluation and ruling out possible infective or noninfective causes is vital in the diagnosis of periodic fever in children. Investigations demonstrate that there isn't a single gene linked to it, suggesting that it may have a multifactorial or polygenic origin, with an environmental trigger causing inflammasome activation and fever flares. Treatment is usually symptomatic, with drugs such as colchicine and cimetidine having shown promising results in trials.

We explored the literature on periodic fever in children for its epidemiology, pathophysiology, the role of various genes and how they influence the disease and associated complications, and its various treatment modalities.

Pericarditis and Autoinflammation: A Clinical and Genetic Analysis of Patients With Idiopathic Recurrent Pericarditis and Monogenic Autoinflammatory Diseases at a National Referral Center

Background Idiopathic recurrent pericarditis (IRP) is an orphan disease that carries significant morbidity, partly driven by corticosteroid dependence. Innate immune modulators, colchicine and anti-interleukin-1 agents, pioneered in monogenic autoinflammatory diseases, have demonstrated remarkable efficacy in trials, suggesting that autoinflammation may contribute to IRP. This study characterizes the phenotype of patients with IRP and monogenic autoinflammatory diseases, and establishes whether autoinflammatory disease genes are associated with IRP. Methods and Results We retrospectively analyzed the medical records of patients with IRP (n=136) and monogenic autoinflammatory diseases (n=1910) attending a national center (London, UK) between 2000 and 2021. We examined 4 genes (MEFV, MVK, NLRP3, TNFRSF1A) by next-generation sequencing in 128 patients with IRP and compared the frequency of rare deleterious variants to controls obtained from the Genome Aggregation Database. In this cohort of patients with IRP, corticosteroid dependence was common (39/136, 28.7%) and was associated with chronic pain (adjusted odds ratio 2.8 [95% CI, 1.3-6.5], P=0.012). IRP frequently manifested with systemic inflammation (raised C-reactive protein [121/136, 89.0%] and extrapericardial effusions [68/136, 50.0%]). Pericarditis was observed in all examined monogenic autoinflammatory diseases (0.4%-3.7% of cases). Rare deleterious MEFV variants were more frequent in IRP than in ancestry-matched controls (allele frequency 9/200 versus 2932/129 200, P=0.040). Conclusions Pericarditis is a feature of interleukin-1 driven monogenic autoinflammatory diseases and IRP is associated with variants in MEFV, a gene involved in interleukin-1β processing. We also found that corticosteroid dependence in IRP is associated with chronic noninflammatory pain. Together these data implicate autoinflammation in IRP and support reducing reliance on corticosteroids in its management.

Neurological and neurodevelopmental symptoms in children with familial Mediterranean fever and their siblings

Familial Mediterranean fever is a common autoinflammatory disease characterized by periodic attacks of fever and serositis. There are few reports describing neurological symptoms in patients with FMF. The aim of this study was to systematically assess the neurologic and developmental involvement in pediatric patients with FMF. Between the years 2016 and 2019, parents of children with FMF were asked to complete a questionnaire regarding the presence of neurological and developmental symptoms in their children with and without FMF. Demographic data, clinical characteristics, and disease course of FMF patients were collected from the medical charts. Neurodevelopmental manifestations were compared between the children with FMF and their siblings. A total of 205 children were enrolled (11.6 ± 4.7 years of age): 111 children with FMF and 94 healthy siblings in the control group. Neurological morbidity was frequently reported in children with FMF: 44 (40%) had recurrent headaches, 31 (28%) ADHD symptoms, 27 (24%) learning disabilities, and 10 (9%) febrile convulsions. Headaches and febrile convulsions were significantly more prevalent in children with FMF as compared to their siblings (ps < 0.05). ADHD and learning disabilities were associated with poor adherence to colchicine treatment.Conslusions: The present study found an increased prevalence of ADHD, learning disabilities, headaches, and febrile seizures in children with FMF. The findings underscore the importance of addressing the neurodevelopmental domain in children with FMF. In addition, detection and treatment of ADHD and learning disabilities could improve adherence with therapy and control of the underlying disease. What is Known: • Familial Mediterranean fever (FMF) is the most common inherited auto-inflammatory disease, characterized by recurrent attacks of fever, serositis, and arthritis. • Some previous case reports also described rare neurological manifestations in children with FMF. What is New: • The study found an increased prevalence of headaches, febrile seizures, ADHD, and learning disabilities, in children with FMF. • The findings underscore the importance of addressing the neurological domain in this population, which could potentially improve adherence with therapy and control of the underlying disease.

The Immunological Impact of IL-1 Family Cytokines on the Epidermal Barrier

The skin barrier would not function without IL-1 family members, but their physiological role in the immunological aspects of skin barrier function are often overlooked. This review summarises the role of IL-1 family cytokines (IL-1α, IL-1β, IL-1Ra, IL-18, IL-33, IL-36α, IL-36β, IL-36γ, IL-36Ra, IL-37 and IL-38) in the skin. We focus on novel aspects of their interaction with commensals and pathogens, the important impact of proteases on cytokine activity, on healing responses and inflammation limiting mechanisms. We discuss IL-1 family cytokines in the context of IL-4/IL-13 and IL-23/IL-17 axis-driven diseases and highlight consequences of human loss/gain of function mutations in activating or inhibitory pathway molecules. This review highlights recent findings that emphasize the importance of IL-1 family cytokines in both physiological and pathological cutaneous inflammation and emergent translational therapeutics that are helping further elucidate these cytokines.

Ocular inflammatory diseases in children with familial Mediterranean fever: a true association or a coincidence?

PURPOSE

To describe the characteristics of patients with familial Mediterranean fever (FMF) with concurrent ocular inflammatory disease (OID) and to analyze possible relations between them.

METHODS

Clinical data were extracted from electronic medical records. Additionally, the medical literature on OIDs reported in patients with FMF was reviewed.

RESULTS

Among 512 pediatric patients with FMF, five cases were found to have OIDs: bilateral anterior chronic uveitis, bilateral panuveitis, recurrent optic neuritis (RON), recurrent orbital myositis (ROM), and acquired Brown's syndrome. The first cases of ROM and acquired Brown's syndrome in FMF have been described in the literature. All cases presented with early-onset typical FMF attacks, carried at least one M694V mutation, and experienced OID while on colchicine.

CONCLUSION

Increased frequency of OIDs in FMF as per the pediatric population and relapsing and chronic course of OIDs occasionally with concurrent FMF attacks suggest that this inflammatory syndrome, especially those carrying M694V mutations, may be a predisposing factor for OIDs.

Assessment of vascular damage in children and young adults with Familial Mediterranean Fever

Familial Mediterranean Fever (FMF) is the most frequent autoinflammatory disease. This study aimed to evaluate the risk of subclinical vascular damage in FMF children, and young adults, using both imaging and laboratory tests. Forty-five FMF patients (mean age 14.3 ± 9.5 years, 33 children) and 44 healthy controls(mean age 13.3 ± 8.6 years, 36 children) were included in the study. The patients were diagnosed according to Tel-Hashomer criteria, were positive for MEFV gene mutation, were treated with colchicine and were evaluated during an attack free-period. The arterial stiffness parameters studied were carotid-femoral pulse wave velocity (PWV), Augmentation Index (Aix), subendocardial viability ratio (SEVR) and carotid intima-media thickness (cIMT). Laboratory parameters, inflammation markers and lipid profile were also evaluated for all participants. There were no significant differences between patients and healthy individuals, as well as in our children population regarding PWV, SEVR, Aix and cIMT. However, significantly higher ESR, CRP and fibrinogen levels were detected in the total population of FMF patients and higher amyloid levels in FMF children, compared to controls. Atherogenic Index of Plasma was significantly higher both in the total patient population and in the subgroup of children, compared to controls. Furthermore, a significant positive correlation between Aix and CRP and a negative correlation between SEVR and ESR became apparent in the pediatric subgroup. Our study demonstrated no significant differences in vascular measurements between FMF patients and controls. The above could be attributed to the regular colchicine treatment, which seems to have a cardioprotective role against vascular damage.

Immunoglobulin A Vasculitis in a Japanese Patient with Complete Familial Mediterranean Fever Carrying MEFV Exon 10 Mutation

Immunoglobulin A (IgA) vasculitis is a systemic small-vessel vasculitis involving the skin, kidney, joints, and gastrointestinal tract. Familial Mediterranean fever (FMF) is the most common autoinflammatory disease characterized by periodic fever, peritonitis, pleuritis, or arthritis. It is well known that FMF may coexist with vasculitis, especially small and medium vessel vasculitis. Here we present a Japanese male patient with FMF who later developed IgA vasculitis and a relapsing disease course. A 51-year-old Japanese male was referred because of upper abdominal pain, arthralgia, and bilateral purpura of the lower limbs. He fulfilled the criteria for IgA vasculitis, which was successfully treated by corticosteroid and immunosuppressive therapy. He had a medical history of periodic fever since the age of 10 years old. The Mediterranean fever (MEFV) gene analysis revealed that he was heterozygous for M694I and E148Q mutations. Colchicine therapy resolved his periodic febrile attacks. To our knowledge, coexistence of FMF with IgA vasculitis has not been reported in East Asia, including Japan. Our case suggests that MEFV gene exon 10 mutations could be related to the development of IgA vasculitis and affects its clinical course.

Fibrinogen-to-Albumin Ratio in Familial Mediterranean Fever: Association with Subclinical Inflammation

BACKGROUND

Familial Mediterranean fever (FMF) is the most seen monogenic periodic fever syndrome characterised by bouts of fever and serositis. It is known that subclinical inflammation (SI) can persist in the symptom-free period and lead to amyloidosis even under colchicine treatment. This study aimed to evaluate the role of the fibrinogen-to-albumin ratio (FAR) in FMF and its correlation with SI.

MATERIAL AND METHODS

A total of 112 patients with FMF and 78 controls were enrolled in this retrospective study. Demographic, laboratory and genetic data were obtained from the hospital records.

RESULTS

The FAR values of the FMF cases were significantly higher than the control group (p<0.001). In the FMF group, the patients with SI had higher FAR values than those without SI (p<0.001). FAR was positively correlated with SI (r=0.413, p<0.001). The receiver operating characteristic curve analysis showed that FAR had a higher area under the curve value than albumin and fibrinogen.

CONCLUSION

Detecting SI in patients with FMF is crucial in preventing amyloidosis, the most devastating complication of FMF. FAR is a simple, inexpensive, easily obtained indicator which can be used for reflecting SI in FMF.

HINTERGRUND

Familiäres Mittelmeerfieber (FMF) ist das am häufigsten auftretende monogene periodische Fiebersyndrom, das durch Fieberschübe und Serositis gekennzeichnet wird. Die subklinische Entzündung (SI) kann bekanntlich auch in der symptomfreien Phase fortbestehen und zu Amyloidose führen, selbst unter Behandlung mit Colchicin. Ziel dieser Studie ist es, die Beziehung zwischen Fibrinogen und Albumin (AFR) bei FMF und deren Korrelation mit SI zu untersuchen.

MATERIAL UND METHODEN

Insgesamt wurden für diese retrospektive Studie 112 Patienten mit FMF und 78 Kontrollpatienten eingeschlossen. Die demographischen, labortechnischen und genetischen Daten wurden aus den Krankenhausunterlagen entnommen.

ERGEBNISSE

Die Werte von AFR bei Patienten mit FMF waren signifikant höher als die der Kontrollgruppe (<0,001). Patienten mit FMF mit SI zeigten höhere AFR-Werte als FMF-Patienten ohne SI (<0,001). AFR korrelierte positiv mit SI (r=0,413, p<0,001). Die Analyse der ROC-Kurve (Receiver Operating Characteristic) zeigte, dass AFR einen höheren Wert der Fläche unter der Kurve (AUC) hatte als Albumin und Fibrinogen.

DISKUSSION

Die Erkennung von SI bei FMF-Patienten ist entscheidend für die Vermeidung von Amyloidose, der schlimmsten Komplikation von FMF. AFR ist ein einfacher, kostengünstiger, leicht durchzuführender Indikator, der in FMF zur Spiegelung von SI verwendet werden kann.

Amyloid storm: acute kidney injury and massive proteinuria, rapidly progressing to end-stage kidney disease in AA amyloidosis of familial Mediterranean fever

OBJECTIVE

Amyloid A nephropathy of FMF usually progresses over many years to end-stage renal disease (ESRD). We aim to describe an acute condition, termed here 'amyloid storm', typically manifesting with a rapid (≤2 weeks) increase in serum creatinine and urine protein, that has never been characterized in FMF amyloidosis.

METHODS

This retrospective analysis features amyloid storm by comparing between FMF amyloidosis patients who have experienced an episode of amyloid storm (study group) and matched patients who have not (control group). The primary outcome was ESRD or death within 1 year from study entry. Featured data were retrieved from hospital files.

RESULTS

The study and control groups, each comprising 20 patients, shared most baseline characteristics. However, they differed on the time from FMF onset to reaching serum creatinine of 1.2 mg/dl [26.5 years (s.d. 15.15) vs 41.55 (10.98), P = 0.001] and the time from the onset of proteinuria to study entry [8.8 years (s.d. 6.83) vs 15.75 (13.05), P = 0.04], culminating in younger age at study entry [39.95 years (s.d. 16.81) vs 48.9 (9.98), respectively, P = 0.05] and suggesting an accelerated progression of kidney disease in the study group. Within 1 year from study entry, 16 patients in the study and 3 in the control groups reached the primary endpoint (P = 0.000). The major triggers of amyloid storm were infections, occurring in 17 of 20 patients.

CONCLUSION

Amyloid storm is a complication of FMF amyloidosis, induced by infection and associated with poor prognosis and death.

Evaluation of S100A12 protein levels in children with familial Mediterranean fever

Background/aim

Familial Mediterranean fever (FMF), the most common autoinflammatory disease in children, is characterized by recurrent febrile episodes. FMF is known to progress with chronic inflammation, particularly during attack periods. This study aimed to investigate the relationship of S100A12, an inflammatory marker, with attacks and inflammatory events in FMF patients.

Materials and methods

The study included 57 patients diagnosed with FMF, 43 in an attack-free period and 14 in an attack period, and 31 healthy children as the control group. Only white blood cell (WBC) count, C-reactive protein (CRP) level, erythrocyte sedimentation rate (ESR), and S100A12 level were analyzed in the control group. In addition, serum amyloid A (SAA), and fibrinogen levels were measured, and a mutation analysis was performed in the patient group. The results were compared among the attack-free period, acute attack FMF and control groups.

Results

The mean age of patients and control group was 10 (2.5–18) and 9.5 (2.5–16) years, respectively. The CRP (p = 0.001), S100A12 (p = 0.003) and ESR (p= 0.001) values differed significantly between the FMF and control groups. S100A12 level (p = 0.027), WBC count (p = 0.003), CRP level (p = 0.0001), ESR (p = 0.004), and fibrinogen level (p = 0.001) differed significantly between the acute attack and attack-free period groups. SAA level (p = 0.05), ESR (p = 0.001), fibrinogen level (p = 0.001), WBC count (p = 0.001), and S100A12 level (p = 0.027) were higher in M694V homozygous FMF patients than in other FMF patients.

Conclusion

Patients with FMF had higher S100A12 levels than the control group, while the mean S100A12 concentration was higher in acute attack period patients than in attack-free period patients. S100A12 level might be an important indicator in the monitoring of chronic inflammation in patients with FMF.

Clinical Implications of S100A12 and Resolvin D1 Serum Levels, and Related Genes in Children with Familial Mediterranean Fever

The aim of this article was to study the role of S100A12 and resolvin D1-related genes and serum levels in the diagnosis and detection of subclinical inflammation in children with familial Mediterranean fever (FMF) during the quiescent stage of the disease. Seventy-eight children with FMF during the silent state and 60 healthy control were studied. Serum S100A12 and resolvin D1 were quantitatively measured using enzyme-linked immunosorbent assay. In addition, the levels of C-reactive protein, erythrocyte sedimentation rate, and hemoglobin were determined. The clinical severity was evaluated. The link between the Mediterranean fever (MEFV) gene and the genes related to the two studied biomarkers was also assessed. Correlation between S100A12 and resolvin D1 and the clinical severity was assessed. The mean serum levels of S100A12 and resolvin D1 were 847.4 and 793.3, respectively, which were highly significantly increased (p = 0.001) compared with the controls (324.3 and 235.1, respectively). The receiver operating characteristic curve test showed that S100A12 had a sensitivity of 97.4% and specificity of 80% with cutoff value of 529.5, while resolvin D1 showed a sensitivity of 100% and specificity of 50% with cutoff value of 231.2. A correlation was detected between the clinical severity and S100A12 and resolvin D1. This study delineated that S100A12 and resolvin D1 are sensitive biomarkers to detect the degree of inflammation in children with FMF during the silent period. Consequently, we recommend adjusting the colchicine dose to ameliorate the disease's symptoms and to improve the quality of life in these patients.

A Novel mRNA Modification Mutation in a Patient With Ligneous Conjunctivitis Coexisting With Heterozygous Familial Mediterranean Fever Mutation

PURPOSE

To describe a novel mRNA mutation associated with ligneous conjunctivitis (LC) in a patient with heterozygous familial Mediterranean fever (FMF) mutation.

METHODS

Case presentation of a patient with LC and heterozygous FMF mutation. The patient was evaluated for various genetically predisposed inflammatory diseases through whole exome sequencing.

RESULTS

LC is a rare inflammatory ocular pathology presenting with recurrent conjunctivitis episodes with eosinophilic fibrin-rich pseudomembranes. FMF is an autoinflammatory disease presenting with recurrent episodes of fever, arthritis, and other inflammatory conditions. Various plasminogen (PLG) gene mutations have been identified in LC, whereas a variety of mutations in the Mediterranean fever (MEFV) gene have been identified in FMF patients. Based on the inflammatory nature of both pathologies, we aimed to evaluate and identify any potential common genetic pathway. We were not able to identify any mutation in PLG gene through whole gene sequencing; however, the patient was positive for heterozygous M680I FMF mutation, and we observed 22% of NM_000301.3:c.2130T>G (p.T710=) variant in mRNA isolated from affected tissue, which was not present in DNA sequence.

CONCLUSIONS

To the best of our knowledge, this is the first case of LC caused by an mRNA mutation coexisting with another genetically predisposed autoinflammatory disease mutation.

Molecular mechanisms of phenotypic variability in monogenic autoinflammatory diseases

Monogenic autoinflammatory diseases are a group of rheumatologic disorders caused by dysregulation in the innate immune system. The molecular mechanisms of these disorders are linked to defects in inflammasome-mediated, NF-κB-mediated or interferon-mediated inflammatory signalling pathways, cytokine receptors, the actin cytoskeleton, proteasome complexes and various enzymes. As with other human disorders, disease-causing variants in a single gene can present with variable expressivity and incomplete penetrance. In some cases, pathogenic variants in the same gene can be inherited either in a recessive or dominant manner and can cause distinct and seemingly unrelated phenotypes, although they have a unifying biochemical mechanism. With an enhanced understanding of protein structure and functionality of protein domains, genotype-phenotype correlations are beginning to be unravelled. Many of the mutated proteins are primarily expressed in haematopoietic cells, and their malfunction leads to systemic inflammation. Disease presentation is also defined by a specific effect of the mutant protein in a particular cell type and, therefore, the resulting phenotype might be more deleterious in one tissue than in another. Many patients present with the expanded immunological disease continuum that includes autoinflammation, immunodeficiency, autoimmunity and atopy, which necessitate genetic testing.

Familial Mediterranean fever (FMF)-response to TNF-blockers used for treatment of FMF patients with concurrent inflammatory diseases

OBJECTIVE

Familial Mediterranean fever (FMF) is the most common interleukin 1 (IL-1)-driven monogenic autoinflammatory disease. Yet published data also suggest that tumor necrosis factor (TNF) may have a role in the pathogenesis of FMF and may serve as a target for treatment. In the present study we evaluate this hypothesis.

METHODS

To this goal, we studied the incidental effect on FMF of TNF-directed treatment, administered to colchicine-refractory FMF patients for the management of a concurrent inflammatory disease. The rates of FMF patients and of treatments with complete or nearly complete FMF response were determined, based on the number of FMF attacks during TNF-blocker exposures. The possible effect of various FMF and non-FMF features on the outcome was determined using comparative analysis. Patients were identified and data were retrieved using electronic files from the FMF clinic.

RESULTS

Twenty-six patients were identified, each receiving ≥1 of four TNF-blockers for a mean duration of 27.6±16.4months. The TNF-blockers were found to induce complete or nearly complete FMF response in 10 (38.5%) of the patients, and in 13 of 50 (26%) exposures. No clinical, genetic, demographic, or therapeutic feature could predict which FMF patient would respond favorably to TNF-blocker therapy.

CONCLUSION

This study suggests that TNF-blockers may be beneficial for a small proportion of colchicine-resistant FMF patients.

PYRIN inflammasome activation abrogates IL1Ra expression providing a new mechanism underlying FMF pathogenesis

OBJECTIVE

Aberrant PYRIN inflammasome activity triggers FMF pathogenesis but the exact mechanism remains elusive and an obstacle to efficient treatment. Herein, we sought to identify PYRIN inflammasome specific mechanisms to improve FMF treatment and diagnostics in the future.

METHODS

PYRIN-specific protein secretion was assessed by proteome analysis in U937 derived macrophages, and specific findings were confirmed in PYRIN inflammasome activated monocytes from healthy blood donors (HD) and FMF patients, stratified by MEFV genotype categories corresponding to a suspected increasing FMF disease severity.

RESULTS

Proteome data revealed differential secretion pattern of IL1Rα from PYRIN and NLRP3 activated U937 derived macrophages, which was verified by ELISA and qPCR. Moreover, PYRIN activation significantly reduced IL1RN mRNA expression (p<0.001) and IL1Rα secretion (p<0.01) in healthy donor- and FMF monocytes, respectively. Independent of MEFV genotype, unstimulated FMF monocytes from colchicine treated patients secreted lower amounts of IL1Rα as compared to healthy donors (p<0.05) and displayed decreased ratios of IL1Rα/IL1β (p<0.05), suggesting a reduced anti-inflammatory capacity.

CONCLUSION

Our data show an inherent lack of IL-1 receptor antagonist expression specific to PYRIN inflammasome activation, providing a new mechanism underlying FMF pathogenesis. The reduced IL1Rα levels in FMF monocytes suggest a diminished anti-inflammatory capacity potentially leaving FMF patient monocytes more sensitive to pro-inflammatory stimuli, regardless of being in colchicine therapy. Thus, considering the potential clinical consequence of reduced monocyte IL1Rα secretion in FMF patients, we suggest further investigations into IL1Rα dynamics and its potential implications for FMF treatment in the future.

Relationship between C-reactive Protein/Albumin Ratio and Subclinical Inflammation in Patients with Familial Mediterranean Fever

Background Familial Mediterranean Fever (FMF), which is characterised by recurrent episodes of fever with serositis, is associated with ongoing inflammation without clinical findings during attack-free periods, leading to amyloidosis, the most important complication of FMF. The objective of this study was to investigate the C-reactive protein/albumin ratio (CAR) as a marker to identify subclinical inflammation in symptom-free FMF children and compare the CAR with other systemic inflammatory markers such as mean platelet volume (MPV), red cell distribution width (RDW), neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR).

Material and Methods We included 100 patients and 70 healthy subjects. Hospital records were obtained to collect data on laboratory findings and genetic mutations.

Results We found that the CAR levels of our FMF patients were significantly higher than those of the control group. We also evaluated that the CAR values had a higher area-under-the-curve value than the other systemic inflammation parameters including CRP, MPV, RDW, NLR, PLR based on Receiver-Operating Characteristics (ROC) analysis.

Conclusion It is important to identify subclinical inflammation in FMF patients with simple, reliable, easily accessible markers to avoid amyloidosis. Although the CAR might be used to assess subclinical inflammation in paediatric FMF patients, the prognostic value of CAR is not superior to CRP. Merging CRP and albumin into a single index thus provides no additional benefit in detecting subclinical inflammation in FMF.

Presentation of a new mutation in FMF and evaluating the frequency of distribution of the MEFV gene mutation in our region with clinical findings

Familial Mediterranean Fever (FMF), which is an autosomal recessive disease characterized by recurrent self-limiting fever, peritonitis, pleuritis, arthritis and erysipelas-like erythemas, has been common among ethnic groups such as Turkish, Armenian, Arabic and Jewish. The clinical presentation is caused by mutations in the MEFV gene encoding the Pyrin protein. In this study, we aimed to present a new mutation that has not been previously defined from the mutations in the MEFV gene which is responsible for the genetic pathology of familial Mediterranean fever and to evaluate the frequency of distribution of the MEFV gene mutation among different ethnic groups living in our region. In present retrospective study, a total of 2639 clinically suspected FMF patients who were referred to Hatay Mustafa Kemal University Hospital between 2010 and 2017 were recorded. MEFV gene mutations were observed using DNA sequence analysis. MEFV mutations were found in 2079 of the 2639 patients (78.7%) Among these patients 184 (6.97%) were homozygous, while 1365 (51.72%) were heterozygous. The most frequently observed mutation was R202Q (1319, 19.55%) followed by E148Q (n = 476, 7.05%), M694V (n = 439, 6.51%), V726A (n = 146, 2.16%) and M680I (n = 135, 2%). In a case clinically diagnosed as FMF, a new mutation called S145G (p. Ser145Gly, c.433A > G) was identified in exon 2 of the MEFV gene. Besides, addition of a new pathogenic MEFV variant to the literature, the relationship between the FMF clinic and homozygous form of R202Q, which was previously considered as a polymorphism, was highlighted.

Autoinflammatory syndromes

Autoinflammatory syndromes are a steadily growing group of inflammatory diseases caused by abnormal regulations of the innate immune system. The clinical presentation is multifaceted, but recurrent fever, skin involvement, joint inflammation and other systemic symptoms of inflammation are characteristic. In contrast to classic autoimmune diseases, autoantibodies or specific T cells are not involved in the pathogenesis. In fact, innate immunity plays the most important role in autoinflammation. While activation of the innate immune system is usually self-limiting in healthy individuals, mutations and dysregulation can lead to chronic and excessive activation of innate immune responses and to the development of autoinflammatory diseases.

Serum Amyloid A in Inflammatory Rheumatic Diseases: A Compendious Review of a Renowned Biomarker

Serum amyloid A (SAA) is an acute phase protein with a significant importance for patients with inflammatory rheumatic diseases (IRD). The central role of SAA in pathogenesis of IRD has been confirmed by recent discoveries, including its involvement in the activation of the inflammasome cascade and recruitment of interleukin 17 producing T helper cells. Clinical utility of SAA in IRD was originally evaluated nearly half a century ago. From the first findings, it was clear that SAA could be used for evaluating disease severity and monitoring disease activity in patients with rheumatoid arthritis and secondary amyloidosis. However, cost-effective and more easily applicable markers, such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), overwhelmed its use in clinical practice. In the light of emerging evidences, SAA has been discerned as a more sensitive biomarker in a wide spectrum of IRD, especially in case of subclinical inflammation. Furthermore, a growing number of studies are confirming the advantages of SAA over many other biomarkers in predicting and monitoring response to biological immunotherapy in IRD patients. Arising scientific discoveries regarding the role of SAA, as well as delineating SAA and its isoforms as the most sensitive biomarkers in various IRD by recently developing proteomic techniques are encouraging the revival of its clinical use. Finally, the most recent findings have shown that SAA is a biomarker of severe Coronavirus disease 2019 (COVID-19). The aim of this review is to discuss the SAA-involving immune system network with emphasis on mechanisms relevant for IRD, as well as usefulness of SAA as a biomarker in various IRD. Therefore, over a hundred original papers were collected through an extensive PubMed and Scopus databases search. These recently arising insights will hopefully lead to a better management of IRD patients and might even inspire the development of new therapeutic strategies with SAA as a target.

The Value of Serum Amyloid A Levels in Familial Mediterranean Fever to Identify Occult Inflammation During Asymptomatic Periods

OBJECTIVE

The aim of this observational study was to evaluate whether there was any correlation between the acute phase reactants in children with familial Mediterranean fever (FMF) during attack and attack-free periods.

METHODS

The study was conducted between June 2016 and January 2018. Clinical features and laboratory parameters of children with FMF during attack and attack-free periods were recorded longitudinally.

RESULTS

The cohort consisted of 168 children with FMF (84 boys, 84 girls). Median values of acute phase reactants during FMF attacks were 433.5 mg/L (34.0-1780.0 mg/L) for serum amyloid A (SAA), 56.7 mg/L (7.6-379.0 mg/L) for C-reactive protein (CRP), and 37.5 mm/h (5-100 mm/h) for erythrocyte sedimentation rate (ESR). Median values for the same tests in attack-free periods were 3.2 mg/L (0.1-25.0 mg/L), 1.7 mg/L (0.1-12.7 mg/L), and 8 mm/h (1-30 mm/h), respectively. Correlation analyses showed that SAA and CRP were highly correlated in FMF attack (r = 0.67, p < 0.01), but no correlation was found between SAA and ESR levels. C-reactive protein was elevated in 13.6%, ESR in 20.8%, and SAA in 28.5% of the patients during attack-free period. Age at onset, sex of the patients, and characteristics of attacks were found to be not associated with elevated SAA in attack-free period. On the other hand, having homozygous exon 10 mutation and having elevated CRP were found to be associated with high SAA in attack-free period.

CONCLUSIONS

C-reactive protein and SAA correlate well with FMF attacks. Therefore, checking for SAA during a FMF attack is not required. However, SAA seems to be the most sensitive method for demonstrating subclinical inflammation in attack-free period. Thus, checking SAA levels might be a valuable tool in selected FMF patients.

Endocan: A Novel Marker for Colchicine Resistance in Familial Mediterranean Fever Patients?

Introduction: Familial Mediterranean fever (FMF) patients had 5-10% colchicine resistance. Although FMF attacks are characterized by acute phase elevation, there are no biomarkers that can show colchicine resistance yet. The serum endocan levels may elevate in inflammatory and auto-inflammatory diseases. Objectives: This study aimed to evaluate serum endocan levels in FMF patients according to whether attack and colchicine resistance or not and also compare them with classical acute phase reactants. Methods: In this single-center and cross-sectional study, a total of 111 FMF patients and 60 healthy individuals were enrolled. All patients' basic demographic and clinical data were recorded and blood samples were collected. Results: A total of 46 (41.4%) FMF patients had colchicine resistance. In comparison to the FMF patients according to colchicine response, colchicine resistance patients had a significantly higher median (IQR) endocan levels than colchicine responsive patients [36.98 ng/ml (97.41) vs. 13.57 ng/ml (27.87), p = 0.007], but there were no differences between in terms of median ESR and CRP levels. Inversely, serum endocan levels were similar during an attack and attack-free period in FMF patients, although ESR and CRP levels were significantly different. Interestingly, the highest serum endocan levels were in the control group. Conclusion: In conclusion, serum endocan levels were higher in colchicine resistance than colchicine responsive patients, but attack state had no effect on serum endocan levels in our study. Unlike ESR and CRP, serum endocan may be a novel biomarker for detection of colchicine resistance and distinguish the FMF attacks.

Familial Mediterranean fever, from pathogenesis to treatment: a contemporary review

Familial Mediterranean fever (FMF) (OMIM #249100) is the most common hereditary autoinflammatory disease in the world. FMF is caused by gain of function mutations of MEFV gene which encodes an immune regulatory protein, pyrin. Over the last few years, we have witnessed several new developments in the pathogenesis, genetic testing, diagnosis, comorbidities, disease related damage and treatment approaches to FMF. Elucidation of some of the pathogenic mechanisms has led to the discovery of pathways involved in inflammatory, metabolic, cardiovascular and degenerative diseases. The use of next generation sequencing in FMF has revealed many new gene variants whose clinical significance may be clarified by developing functional assays and biomarkers. Clinically, although FMF is considered an episodic disease characterized by brief attacks, recent systematic studies have defined several associated chronic inflammatory conditions. Colchicine is the mainstay of FMF treatment, and interleukin (IL)-1 antagonists are the treatment of choice in refractory or intolerant cases. Experience of IL-1 antagonists, anakinra and canakinumab, is now available in thousands of colchicine resistant or intolerant FMF patients. In this contemporary review, we surveyed current FMF knowledge in the light of these recent advances.