Genetic risk factors of amyloidogenesis in familial Mediterranean fever

Predicting genetic risk factors for AA amyloidosis in Algerian patients with familial Mediterranean fever

Renal amyloid-associated (AA) amyloidosis is a harmful complication of familial Mediterranean fever (FMF). Its occurrence involves polymorphisms and mutations in the Serum Amyloid A1 (SAA1) and Mediterranean Fever (MEFV) genes, respectively. In Algeria, the association between SAA1 variants and FMF-related amyloidosis was not investigated, hence the aim of this case-control study. It included 60 healthy controls and 60 unrelated FMF patients (39 with amyloidosis, and 21 without amyloidosis). All were genotyped for the SAA1 alleles (SAA1.1, SAA1.5, and SAA1.3), and a subset of them for the - 13 C/T polymorphism by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Comparisons between genotype and allele frequencies were performed using Chi-square and Fisher tests. The SAA1.1/1.1 genotype was predominant in amyloid FMF patients, compared to non-amyloid FMF patients (p = 0.001) and controls (p < 0.0001). SAA1.1/1.5 was higher in non-amyloid patients (p = 0.0069) and in controls (p = 0.0082) than in patients with amyloidosis. Bivariate logistic regression revealed an increased risk of AA amyloidosis with three genotypes, SAA1.1/1.1 [odds ratio 7.589 (OR); 95% confidence interval (CI): 2.130-27.041] (p = 0.0018), SAA1.1/1.3 [OR 5.700; 95% CI: 1.435-22.644] (p = 0.0134), and M694I/M694I [OR 4.6; 95% CI: 1.400-15.117] (p = 0.0119). The SAA1.1/1.5 genotype [OR 0.152; 95% CI: 0.040-0.587] (p = 0.0062) was protective against amyloidosis. In all groups, the - 13 C/C genotype predominated, and was not related to renal complication [OR 0.88; 95% CI: 0.07-10.43] (p = 0.915). In conclusion, in contrast to the - 13 C/T polymorphism, the SAA1.1/1.1, SAA1.1/1.3 and M694I/M694I genotypes may increase the risk of developing renal AA amyloidosis in the Algerian population.

Concurrence of familial Mediterranean fever and Behçet's disease: a case report and review of the literature

BACKGROUND

Familial Mediterranean fever and Behçet's disease are distinct disorders that are prevalent in the Mediterranean and Middle Eastern populations. They are characterized by unprovoked inflammatory episodes caused by overexpression of proinflammatory cytokines. Although reported previously, the overlapping presentation of familial Mediterranean fever and Behçet's disease remains uncommon.

CASE PRESENTATION

A 46-year-old Lebanese-Canadian man who presented with recurrent oral and genital ulcers, polyarticular synovitis, ocular swelling, recurrent infections, and fevers was later found to have heterozygous mutations of pathogenic MEFV c.2080A > G (p. Met 694Val) and c.2082G > A (p.Met694IIe) genes indicating familial Mediterranean fever. He was treated with prednisone, colchicine, and azathioprine, with inadequate symptoms control. Treatment was complicated by recurrent infections.

CONCLUSIONS

Our case contributes to the growing literature demonstrating the presentation of predominantly Behçet's disease-like features in the setting of diagnosis of familial Mediterranean fever. These findings emphasize that clinicians should be aware that patients with familial Mediterranean fever may present with Behçet's disease-like clinical manifestations.

Apoptosis-associated speck-like protein containing a CARD (ASC), TNF Like Factor 1a(TL-1a) and B Cell Chemoattractant Chemokine Ligand 13(CXCL-13) expression profiles in familial Mediterranean fever (FMF) patients

Objectives: This study was carried out to compare the expression levels of ASC(Apoptosis Associated Speck Like Protein Containing a CARD), TL-1a(TNF Like Factor 1a) and CXCL 13(B Cell Chemoattractant Chemokine Ligand 13) genes in FMF patients According to Tell-Hashomer Criteria and Genetic analysis result in Düzce University Research and Application Hospital with healthy controls and to determine their clinical significance in FMF. Method: 36 patients (20 girls, 16 boys) and 12 healthy controls (7 girls, 5 boys) were included in the study. RNA was isolated from the peripheral blood of each individual and expression levels of ASC, TL-1a and CXCL 13 genes were determined. Routine biochemical parameters were also determined. Result: CXCL 13 and TL-1a gene expression levels were significantly increased in patients with FMF, the expression level of the ASC gene was found to be increased in FMF patients, but not significantly. Conclusion: The expression levels of these genes may be related to the pathogenesis of the disease and these genes could be used as a marker in the early diagnosis of the disease.

Optical coherence tomography-angiographic vascular densities in Familial Mediterranean Fever (FMF) Patients with M694V Mutations

Familial Mediterranean fever (FMF) is a hereditary auto-inflammatory disease with accompanying findings of amyloidosis and vasculitis. M694V is one of the most common mutations associated with amyloidosis. This study compared the macular optical coherence tomography angiography measurements in FMF patients who were genetically verified to carry the M694V mutation of the MEFV gene to those in healthy controls. The vessel densities (VDs) of superficial (SVP) and deep vascular plexus (DVP) of the retina, and choriocapillaris, foveal avascular zone (FAZ) perimetry, foveal VD 300µ around the FAZ (FD-300), acirculatory index (AI) and non-flow area were measured with  optical coherence tomography angiography (OCT-A). The FMF and control groups were matched for age and gender. Compound heterozygous pathogenic variants were excluded. Thirty-eight FMF patients with M694V mutations (28 heterozygous and 10 homozygous) and 40 healthy controls were included. The two groups were similar with the regard to age and gender (P=0.88 and P=0.49, respectively). None of the investigated parameters, including the vessel densities of the SVP and DVP, and choriocapillaris, FAZ perimetry, FD-300, AI, and non-flow area showed a statistically significant difference between the FMF and control groups. The macular vessel density measurements and FAZ parameters of FMF patients with M694V mutations do not differ from age- and sex-matched healthy controls.

Familial Mediterranean fever in children and adolescents: factors for colchicine dosage and predicting parameters for dose increase

Objectives

The aim was to analyse factors influencing the individual colchicine dose in children with FMF, to evaluate the impact of dose adjustment on the clinical course and inflammation and to identify clinical parameters and biomarkers that predict dose increase in the near future.

Methods

Data from 409 paediatric FMF patients (4566 visits) derived from the national auto-inflammatory diseases registry were analysed. Serum concentrations of S100 molecules were determined by ELISA.

Results

The age-dependent colchicine dose is influenced by the present genotype. The body surface area is the anthropometric parameter that correlates best with the applied dosages. Colchicine introduction and dose increase lead to significant reduction of clinical symptoms and inflammation. During established colchicine therapy, an increase of one single biomarker increases the likelihood of a dose increment in the next 12 months with a factor of 1.62-1.94. A combination of biomarkers including S100 molecules increases this odds ratio up to 4.66 when analysing all patients and up to 7.27 when analysing patients with a high risk of severe disease.

Conclusion

Colchicine therapy is currently guided mainly by the occurrence of clinical symptoms and serological inflammation. Other factors, such as the genotype, the body surface area and biomarkers, will help to manage colchicine therapy in a more individualized fashion. The additional analysis of S100 molecules as sensitive biomarkers will help to identify patients at risk for dose increases in the near future.

Risk factors for AA amyloidosis in Germany

OBJECTIVE

To identify risk factors for serum amyloid-A (AA) amyloidosis in patients living in Germany.

METHODS

Clinical and genetic data were obtained from 71 patients with AA amyloidosis. SAA1 genotypes were analyzed in 231 individuals. Control groups comprised 45 patients with long-standing inflammatory diseases without AA amyloidosis and 56 age-matched patients without any inflammatory disease.

RESULTS

The most frequent underlying diseases of AA amyloidosis were familial Mediterranean fever (FMF) (n = 24, 34%) and inflammatory rheumatic diseases (n = 30, 42%). Patients without any known underlying disease (n = 11, 16%) were considered as having idiopathic AA amyloidosis. Patients with FMF were significantly younger at disease onset and younger at diagnosis of AA amyloidosis compared with patients with rheumatic diseases. Patients with idiopathic AA amyloidosis were older than patients with definite rheumatic diseases. Patients with FMF and high penetrance MEFV gene mutations had a relative risk of 1.73 for AA amyloidosis. Patients with FMF or a rheumatic disease and the SAA1 α/α genotype had a relative risk of 4.86 and 2.53, respectively, for developing an AA amyloidosis. The prevalence of this risk genotype was 36% in German patients without an inflammatory disease, 92% in German patients with AA amyloidosis and 100% in German patients with idiopathic AA amyloidosis.

CONCLUSIONS

Risk factors for AA amyloidosis are the presence of a hereditary autoinflammatory or chronic rheumatic disease, elevated C-reactive protein and SAA serum levels, a long delay of a sufficient therapy, an advanced age and the SAA1α/α genotype.

Bcıı--RFLP profiles for serum amiloid A1 and mutated MEFV gene prevalence in chronic renal failure patients requiring long-term hemodialysis

BACKGROUND AND AIM

There is an increased mortality risk in long-term hemodialysis patients of renal failure due to the chronic inflammation. The relationship between the chronic renal failure (CRF) and the role of familial genetic markers remains incompletely understood. In the current study, it was aimed to find out the prevalence of common MEFV gene mutations and BcII polymorphism in serum amyloid A1 (SAA1) gene in chronic renal patients (CRF) who require long-term hemodialysis.

METHOD

Current cohort includes 242 CRF patients and 245 healthy individuals from the same population. Total genomic DNA was isolated from peripheral blood-EDTA samples and genotyping of target MEFV gene was carried out by reverse hybridization Strip Assay and real-time techniques. The SAA1 gene was genotyped by the BclI-RFLP method.

RESULTS

Increased mutated MEFV genotypes were found in current CRF patients when compared with the control group from the same ethnicity and the difference was statistically significant (Table 2) (OR: 4.9401, 95% CI: 3.0694-7.9509), p<0.0001. The most frequent point mutations were M694V and E148Q. The mutated T allel frequency in the SAA1 gene was also different when compared with the healthy controls and the difference was found to be statistically significant (χ2: 13.18; p=0.000).

CONCLUSIONS

The current results indicate the germ-line mutations in both genetic biomarkers (MEFV and SAA1 genes) that are related to inflammation and amyloidosis processes may play a crucial role in CRF pathogenesis due to the long-term chronic inflammation.

Erysipelas-like erythema of familial Mediterranean fever syndrome: a case report with emphasis on histopathologic diagnostic clues

We report histopathological findings in a case of familial Mediterranean fever (FMF) syndrome with an erysipelas-like erythema (ELE). ELE is the only pathognomic cutaneous manifestation of FMF. ELE is characterized by well-demarcated, tender, erythematous and infiltrated plaques recurring on the same site and resolving spontaneously within 48-72 h. FMF is a monogenic autoinflammatory syndrome highlighted by recurrent fever associated with polyserositis involving mainly the peritoneum, synovium and pleura. FMF results from a mutation of the MEFV gene, which encodes for pyrin, leading to Il-1β activation and promoting neutrophil migration into the dermis. Histopathological findings in our case showed a sparse superficial perivascular and interstitial lymphocytic infiltrate admixed with some neutrophils, no eosinophils and mild papillary dermal edema. Venules and lymphatics were dilated, though no vasculitis was identified. Neutrophils are the most common cutaneous marker of autoinflammation, and cutaneous manifestations of monogenic autoinflammatory syndromes are represented by the spectrum of aseptic neutrophilic dermatoses. Neutrophils in the presence of recurrent fever and in the correct clinical context of recurrent erysipelas in the same site are a diagnostic clue for FMF.

Familial Mediterranean fever: risk factors, causes of death, and prognosis in the colchicine era

We assessed the risk factors and causes of death in patients with familial Mediterranean fever (FMF) in an era when colchicine is the standard therapy for all patients.This study included all FMF patients who had presented to any of the internal medicine, rheumatology, or nephrology clinics at Dokuz Eylul University Hospital between 1992 and 2009. Of the 650 patients with FMF identified, 587 (90.3%) had either a face-to-face (n = 380) or telephone (n = 193) interview, or were confirmed as deceased. A structured questionnaire was used to obtain socioeconomic and demographic data, presenting and cumulative clinical features, and disease severity scores.During the follow-up period mortality was analyzed by calculating age- and sex-standardized mortality ratio (SMR) according to the mortality statistics of the Turkish population. Factors predictive of mortality were evaluated using Kaplan-Meier and Cox proportional hazard models. Sixty-three (9.7%) patients whose initial demographic and major clinical characteristics were similar to the rest of the group could not be contacted during the study period.Most (94.2%) patients were on colchicine at the time of the study. Thirty-seven (6.3%) patients had biopsy-verified amyloidosis, and 44 (7.5%) had renal disease. During a median follow-up of 6 years, 14 patients (9 women) died, and amyloidosis and its related complications were the leading causes of death in 7 patients. Univariate analysis revealed that increasing age, coronary heart disease, hypertension, renal disease, and amyloidosis were associated with mortality. However, Cox regression analysis showed amyloidosis as the only significant predictor of mortality (p < 0.001). The overall patient survival rate was not significantly different from the age- and sex-matched Turkish general population (SMR, 1.48; 95% confidence interval, 0.817-2.49).Our findings suggest that although the survival of FMF patients in the colchicine era is comparable to that of the general population, renal involvement still predicts mortality.

Unresponsiveness to colchicine therapy in patients with familial Mediterranean fever homozygous for the M694V mutation

OBJECTIVE

More than 50 disease-associated mutations of the Mediterranean fever gene (MEFV) have been identified in familial Mediterranean fever (FMF), some of which were shown to have different clinical, diagnostic, prognostic, and therapeutic implications. The aim of our study was to define the frequency of mutation type, genotype-phenotype correlation, and response to colchicine treatment in patients with FMF.

METHODS

This study included 222 pediatric FMF patients. All patients were investigated for 6 MEFV mutations. Then patients were divided into 3 groups according to the presence of M694V mutation on both of the alleles (homozygotes), on only 1 allele (heterozygotes), and on none of the alleles, and compared according to their phenotypic characteristics and response to treatment. M694V/M694V was denoted Group A, M694V/Other Group B, and Other/Other, Group C.

RESULTS

Complete colchicine response was significantly lower while the rate of unresponsiveness was significantly higher in Group A compared to Groups B and C (p = 0.031, p < 0.001 and p = 0.005, p = 0.029, respectively). No differences except proteinuria were found between the phenotypic features of 3 groups. Group C had the lowest rate of proteinuria development (p = 0.024). All the amyloidosis patients were in Group A.

CONCLUSION

Our results indicate that the M694V/M694V mutation is associated with lower response to colchicine treatment. Therefore, patients homozygous for M694V/M694V may be carrying an increased risk for development of amyloidosis.

The role of inflammatory cytokines and NF-kappaB/MAPK signaling pathways in the evolution of familial Mediterranean fever: current clinical perspectives and potential therapeutic approaches

Familial Mediterranean fever (FMF) is one of the social and health care problems for several populations that is known as a historically endemic disease of inflammatory nature. FMF, albeit a rare disorder, is characterized by recurrent fevers and painful inflammation of various body parts, especially the abdomen, lungs, and joints. FMF is typically characterized by inflammation of the abdominal lining (peritonitis), inflammation of the lining surrounding the lungs (pleurisy), painful, swollen joints (arthralgia and occasionally arthritis), and a characteristic ankle rash, a condition that is referred to as recurrent polyserositis, or familial paroxysmal polyserositis. Moreover, FMF is an inherited inflammatory disorder usually occurring in people of Mediterranean origin - including Sephardic Jews, Arabs, Armenians, and Turks; but it may ostensibly affect any other ethnic group, however, rarely. While there's no cure for this disorder, FMF is typically diagnosed during childhood, and signs and symptoms are treatable - or even preventable - by specialized medical attrition. The inflammatory signaling pathways associated with the evolution of FMF are currently being unraveled has that has therapeutic repercussions. In this review, I recap major concepts associated with the cellular and molecular immunology of FMF, especially shedding light on the likely roles of inflammatory cytokines, the transcription factor nuclear factor (NF)-kappaB, and the superfamily of mitogen-activated protein kinases (MAPKs). Furthermore, I summarize current advances for the clinical treatments available for FMF.

MEFV mutations in patients with Familial Mediterranean Fever from the Aegean region of Turkey

Familial Mediterranean Fever (FMF) which is frequently present in Mediterranean populations is caused by mutations in the MEFV gene. According to recent data, MEFV mutations are not the only cause of FMF, but these are major genetic determinants which cause FMF. It has also been suggested that there may be a number of other genes causing FMF. The MEFV gene is located at 16p13.3 and encodes a protein, pyrin/marenostrin. More than 70 disease associated mutations and totally 186 mutations and polymorphisms have been defined in affected individuals. We have retrospectively evaluated the molecular test results of 1,201 patients identified as having FMF clinical symptoms referred to the Molecular Genetics Laboratory of the Department of Medical Genetics, Faculty of Medicine, Ege University, Izmir/Turkey over the last 4 years. Patients were tested for 12 common mutations in the MEFV gene using a strip assay method (Innogenetics, Belgium). Out of the 1,201 patients tested (2,402 chromosomes) in the Aegean region in Turkey, 654 (54.45%) did not carry any mutations, among the 547 (45.55%) patients with mutations 246 patients were either homozygous (101) or compound heterozygous (145), 296 carried only one detected mutation, and five patients had three mutations. Allelic frequencies for the four most common mutations in the mutation positive groups were 47.60% (M694V), 16.75% (E148Q), 12.95% (V726A), 11.94% (M680I G/C).The remaining alleles (10.76%) showed rare mutations which were R761H, P369S, A744S, K695R, F479L, M694I. When the frequencies of mutations detected in our group were compared to the frequencies reported in the other regions of Turkey, an increase in V726A mutation frequency was observed. No patient showed a I692del mutation which is sometimes evident in other Mediterranean populations.

Increased susceptibility of serum amyloid A 1.1 to degradation by MMP-1: potential explanation for higher risk of type AA amyloidosis

OBJECTIVE

Genetic polymorphisms in serum amyloid A (SAA) have been shown to substantially influence the risk of developing type AA amyloidosis. Recently, a role for MMP-1 has been suggested in the pathogenesis of AA amyloidosis. Therefore, we investigated if the SAA1 isotypes are differentially degraded by MMP-1.

METHODS

Degradation of different SAA isotypes by MMP-1 was assessed by immunoblotting. MALDI-TOF mass spectrometry was used to identify degradation fragments.

RESULTS

We found that SAA1.5 is more resistant to degradation by MMP-1 than SAA1.1. This difference is caused by the capacity of MMP-1 to cleave at the site of the polymorphism at position 57.

CONCLUSION

These results may explain the higher risk of amyloidosis in patients with a SAA1.1/1.1 genotype vs SAA1.5/1.5 or SAA1.1/1.5 genotype. In addition, the impaired degradation of SAA1.5 by MMP-1 could also explain the higher serum SAA concentrations in persons with a SAA1.5 genotype.

Protracted familial mediterranean fever arthritis presenting as septic arthritis

In Familial Mediterranean Fever (FMF), arthritis is the initial symptom in 25% of patients. Although FMF arthritis is acute and self-limited, in 5% of cases protracted arthritis usually affecting large joints such as knee may occur. In this report, two cases are presented who were initially diagnosed as septic arthritis, first of which had four and the second had two synovectomy operations with the diagnosis of septic arthritis. Later on they were diagnosed as FMF with detailed history. We aimed to emphasize the importance of diagnosis of FMF, which is based mainly on history and clinical features in order to prevent unnecessary operations and suffering of the patient.

AGGRESCAN: a server for the prediction and evaluation of "hot spots" of aggregation in polypeptides

Background

Protein aggregation correlates with the development of several debilitating human disorders of growing incidence, such as Alzheimer's and Parkinson's diseases. On the biotechnological side, protein production is often hampered by the accumulation of recombinant proteins into aggregates. Thus, the development of methods to anticipate the aggregation properties of polypeptides is receiving increasing attention. AGGRESCAN is a web-based software for the prediction of aggregation-prone segments in protein sequences, the analysis of the effect of mutations on protein aggregation propensities and the comparison of the aggregation properties of different proteins or protein sets.

Results

AGGRESCAN is based on an aggregation-propensity scale for natural amino acids derived from in vivo experiments and on the assumption that short and specific sequence stretches modulate protein aggregation. The algorithm is shown to identify a series of protein fragments involved in the aggregation of disease-related proteins and to predict the effect of genetic mutations on their deposition propensities. It also provides new insights into the differential aggregation properties displayed by globular proteins, natively unfolded polypeptides, amyloidogenic proteins and proteins found in bacterial inclusion bodies.

Conclusion

By identifying aggregation-prone segments in proteins, AGGRESCAN shall facilitate (i) the identification of possible therapeutic targets for anti-depositional strategies in conformational diseases and (ii) the anticipation of aggregation phenomena during storage or recombinant production of bioactive polypeptides or polypeptide sets.