The M694I/M694I genotype: A genetic risk factor of AA-amyloidosis in a group of Algerian patients with 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.

Familial Mediterranean fever and microRNAs

Familial Mediterranean fever (FMF) is an inherited disorder caused by the gain of function mutations in MEFV (MEditerranean FeVer) gene loci. FMF affects more than 100,000 people worldwide and generally seen in the eastern Mediterranean region and causes the lifelong diseases which have a significant effect on the patient's life quality and health systems. The identification of low penetrant or heterozygous MEFV gene mutations in clinically diagnosed FMF patients was considered that epigenetic or environmental factors may display a role in FMF pathogenesis. Epigenetics might be defined as heritable changes that affect gene expression without any changes in the genome. MicroRNAs (miRNAs) are the main group of small noncoding RNAs, and an important element of epigenetic mechanisms and their discoveries revolutionized our knowledge about biological processes, such as malignant, infectious and autoimmune mechanisms, and contributed to the development of the epigenetic areas. In this review, the studies focusing on the roles of miRNAs in FMF pathogenesis in the last decades were examined and the importance of miRNAs as therapeutic agents which are promising for diagnosis and treatment was discussed.

Spectrum of auto-inflammatory diseases in Morocco: a monocentric experience

Objective

Auto-inflammatory diseases (AIDs) result from mutations in genes of the innate immune system leading to periodic multisystemic inflammation. We aimed to describe the clinical, biological and molecular features (when available) and outcomes of Moroccan patients with AIDs.

Methods

Patient data were collected retrospectively and analysed over a 13-year period.

Results

Among 30 patients, 60% had FMF, 16% mevalonate kinase deficiency (MKD) and 24% other AIDs. The mean age at first consultation was 6.9 years, and the mean diagnostic delay was 3 years. Consanguinity was reported in 16 cases. IgA vasculitis was associated with 33% of FMF patients, in whom the main clinical features were fever (88.8%), abdominal pain (100%), arthralgias (88.8%) and arthritis (50%), and the most frequent mutation was M694V (66%). All FMF patients were treated with colchicine. Most MKD patients were confirmed by elevated urinary mevalonic acid levels, and four of five MKD patients received targeted therapy. Chronic recurrent osteomyelitis patients were confirmed by radiological and histological analysis. Two cases of Marshall syndrome were diagnosed according to validated criteria. A case of familial pustular psoriasis was diagnosed based on histological analysis and a patient with Muckle-Wells syndrome by clinical features. The outcome was favourable in 76%, partial in 13%, and three deaths were reported.

Conclusion

FMF and MKD are the most reported diseases. AIDs are probably underestimated because they are unknown to clinicians. The aim of this work is to raise awareness among paediatricians about AIDs and create a network for best practice.

MEFV gene allele frequency and genotype distribution in 3230 patients' analyses by next generation sequencing methods

Familial Mediterranean Fever (FMF, OMIM ID: 249100) is the most common autoinflammatory, autosomal recessive disease caused by mutations in the MEFV gene. It is widespread in the Mediterranean, primarily among Turkish, Armenian, Arab and Jewish. This study aims to examine genotype distributions of common MEFV variants in the Turkish population using targeted NGS and to evaluate all rare mutations. It included 3230 people applying to Ege University Children's Hospital Molecular Medicine Laboratory with the suspicion of autoinflammatory disease between 2017 and 2021. MEFV missense variant was detected in 1839 (56.9%) individuals. One or more mutations were found in them. 1063 patients were heterozygous (57.8%), 410 were compound heterozygous (22.3%), 238 were complex genotype (12.9%), and 128 were homozygous (7%). 56 different mutations and 141 genotypes were detected, two of which were novel (p.His87Arg, c.260A > G and p.Leu396Phe, c.1186C > T). These were determined as 6benign, 40 uncertain significant, 3 likely pathogenic and 7 pathogenic according to the ACMG classification. The most common ones were R202Q (n = 1097, 37.48%), E148Q (n = 512, 17.49%), M694V (n = 493, 16.84%), V726A (n = 155, 5.30%), M680I (n = 150, 5.12%), P369S (n = 108, 3.69%), R408Q (n = 95, 3.25%) respectively. They constitute 89.17 % of the entire patient population. In conclusion, DNA variants/mutations in the MEFV gene were evaluated in 3230 patients. To date, no mutation screening has been encountered in such a large population using NGS. Genotype distributions of both common and rare mutations were revealed. The obtained data will hopefully contribute to the future genotype-phenotype studies of FMF disease.

Contribution of Arab Countries to Familial Mediterranean Fever Research: a PubMed-based bibliometric analysis

Familial Mediterranean Fever (FMF) is an inherited autoinflammatory disease. One of the feared complications of FMF, amyloidosis is often correlated with an increased mortality rate. The severity of the disease is linked with different mutations in the MEFV gene that may favor different outcomes (amyloidosis, Bechet's disease…). Although several countries worldwide contribute remarkably to research related to FMF, Arab countries make up only a small part of this contribution. This study aims to estimate numerically the contribution of the Arab world to research conducted on FMF. PubMed is used to quantitate the number of FMF-related articles published by each Arab country from 2004 till 2019. The retrieved numbers are normalized with respect to each country's average population and average Gross Domestic Product (GDP) and are also compared to those of some non-Arab countries having high FMF prevalence. In comparison with some non-Arab countries, the Arab world has a minor contribution of 3.80% to the total FMF-related publications, faced by 24.93% solely by Turkey. Out of total research done by Arab countries, FMF-related articles constitute no more than 0.133%. When normalized against the average population, Tunisia ranks first, followed by Lebanon. Similarly, normalizing the retrieved numbers of articles against average GDP shows that Tunisia and Lebanon come first and second, respectively. Only 8 Arab countries published a total of 13 articles concerning amyloidosis which makes 4.7% of the total Arabic FMF published articles. This study reflects an undoubtable need for more research to be conducted on FMF by the Arab countries, which suffer greatly from immense shortage in research productivity, due to the many obstacles and limitations these countries face every day.

Differential mutational profiles of familial Mediterranean fever in North Africa

Familial Mediterranean fever (FMF) is a recessive autoinflammatory disease, mainly occurring in the eastern Mediterranean. In these populations, the five FMF founder mutations are differently distributed. In Algeria, the FMF-causing variants remain poorly explored. This retrospective study aims to report the mutational profile of Algerian FMF patients and to compare it with North African FMF patients. One hundred eighty-three unrelated patients clinically suspected of FMF were recruited from various Algerian hospitals (2007-2015) and tested for mutations in exon 10 of MEFV gene. Molecular analysis identified 144 mutant alleles among 87 of 183 patients (47.5%). p.M694I was the most prevalent pathogenic allele, accounting for 63.2% of mutant alleles, followed by p.M694V and p.M680I occurring with a same frequency (14.5%). Others, p.A744S (6.2%) and p.I692del (1.3%), are less frequent. Interestingly, p.M694I was the most recurrent in patients with renal AA-amyloidosis. Our results provide the first genetic data on FMF in Algeria, demonstrating the predominance of p.M694I and the absence of p.V726A, compared to other North African countries (Morocco, Tunisia, and Egypt). In conclusion, North African FMF patients display differential mutational profiles that may result from the difference in ethnic origin and the genetic heterogeneity among these populations.

Altered expression of apoptosis-related, circulating cell-free miRNAs in children with familial Mediterranean fever: a cross-sectional study

OBJECTIVES

Familial Mediterranean Fever (FMF) is the most common hereditary autoinflammatory disorder characterized by recurrent fever and serositis episodes. Identification of low penetrant or heterozygous MEFV mutations in clinically diagnosed FMF patients did raise a concern on whether epigenetic or environmental factors play an additional role in FMF pathogenesis. We aimed to investigate the expression profile of apoptosis-related miRNAs in FMF and their influence on clinical manifestations in the present study.

METHOD

191 pediatric FMF patients and 31 healthy children included in the study. Expressions of 33 apoptosis-related, circulating cell-free miRNAs were evaluated by a quantitative polymerase chain reaction, statistically calculated within ΔΔCt values and fold changes were evaluated by Welch T test, in which p < 0.05 were considered to be significant.

RESULTS

Nineteen miRNAs, including let-7a-5p, let-7c, let-7 g-5p, miR-15b-5p, miR-16-5p, miR-17-5p, miR-23a-3p, miR-24-3p, miR-25-3p, miR-26a-5p, miR-26b-5p, miR-27a-3p, miR-29c-3p, miR-30a-5p, miR-30d-5p, miR-30e-5p, miR-106b-5p, miR-146a-5p, and miR-195-5p, were found down-regulated; miR-15a-5p, miR-29b-3p, miR-181a-5p, miR-181b-5p, miR-181c-5p, miR-214-3p, and miR-365a-3p were up-regulated in FMF patients. In detail, these miRNAs were similar among FMF patients in terms of genotype, colchicine response, and having an inflammatory attack during analysis.

CONCLUSION

We found that 26 apoptosis-related circulating miRNAs were deregulated in children with FMF. Thus, we speculate that these miRNAs have a role in FMF pathogenesis via apoptotic mechanisms.

Pattern and diagnostic evaluation of systemic autoinflammatory diseases other than familial Mediterranean fever among Arab children: a multicenter study from the Pediatric Rheumatology Arab Group (PRAG)

To define the spectrum and phenotypic characteristics of systemic autoinflammatory diseases (SAIDs) other than familial Mediterranean fever (FMF) in Arab children and to delineate diagnostic evaluation. Data retrospectively collected on patients with clinical and/or genetically proven SAIDs other than FMF at 10 tertiary Arab pediatric rheumatology clinics from 1990 to 2018. The collected data comprised the clinical findings and diagnostic evaluation including genetic testing, the provided treatment and the accrual damage related to SAIDs. A total of 144 patients (93 female) with a median age at onset of 2.5 (range 0.1-12) years were enrolled. The initial diagnosis was inaccurate in 49.3%. Consanguinity rate among parents was 74.6%. The median time-to-diagnosis for all SAIDs was 2.5 (range 0.1-10) years. There were 104 patients (72.2%) with a confirmed diagnosis and 40 patients with suspected SAIDs. Seventy-two had monogenic and 66 patients with multifactorial SAIDs while six patients had undifferentiated SAIDs. The most frequent monogenic SAIDs were LACC1 mediated monogenic disorders (n = 23) followed by CAPS (12), TRAPS (12), HIDS (12), and Majeed's syndrome (6). The most frequent multifactorial SAIDs was CRMO (34), followed by PFAPA (18), and early onset sarcoidosis (EOS) (14). Genetic analysis was performed in 69 patients; 50 patients had genetically confirmed disease. Corticosteroid used for 93 patients while biologic agents for 96 patients. Overall, growth failure was the most frequent accrual damage (36%), followed by cognitive impairment (13%). There were three deaths because of infection. This study shows a heterogenous spectrum of SAIDs with a high number of genetically confirmed monogenic diseases; notably, LACC1 associated diseases. Hopefully, this work will be the first step for a prospective registry for SAIDs in Arab countries.

Renal Amyloidosis in Deficiency of Adenosine Deaminase 2: Successful Experience With Canakinumab

Deficiency of adenosine deaminase 2 (DADA2) is a rare autoinflammatory disease that was firstly described in patients with early-onset strokes, livedo reticularis, and periodic fever resembling polyarteritis nodosa. In reported case series, researchers described highly variable manifestations, including autoimmunity, immunodeficiency, hepatosplenomegaly, pancytopenia, ichthyosiform rash, and arthritis, in patients with DADA2. A thirteen-year-old female patient who was born to consanguineous parents was admitted to our hospital with generalized edema and leg pain. A physical examination revealed splenomegaly and left knee arthritis. Nephrotic-range proteinuria and hypoalbuminemia were present, and a renal biopsy revealed amyloidosis. Despite the absence of periodic fever and livedo reticularis, our patient had suggestive features of DADA2, including low serum immunoglobulin G and immunoglobulin M levels, hepatosplenomegaly, and renal amyloidosis. We found a heterozygote Met694Val mutation in the Mediterranean fever gene and a novel homozygote Thr317Argfs*25 (c.950-950delCys) mutation in the cat eye chromosome region 1 gene. A functional analysis revealed absent plasma adenosine deaminase 2 activity. Canakinumab was administered because of unresponsive proteinuria despite 2 months of treatment with colchicine and methylprednisolone. Proteinuria improved after 7 doses of canakinumab. In conclusion, DADA2 should be considered in the differential diagnosis of renal amyloidosis, particularly in the absence of homozygote Mediterranean fever mutations. Although anti-tumor necrosis factor agents are widely offered in DADA2 treatment, we speculate that canakinumab may be an appropriate treatment of renal amyloidosis in DADA2.

Familial Mediterranean fever (FMF) phenotype in patients homozygous to the MEFV M694V mutation

The clinical presentation of familial Mediterranean fever (FMF) is remarkably variable, ranging from a quiescent to a severe and disabling disease. The M694V mutation is one of approximately 300 published genetic variations in the FMF gene. While some studies have reported a more severe phenotype for the homozygous M694V mutation, studies dedicated solely to featuring the phenotype of homozygous M694V genotype are meager. The objective of the study was to present a comprehensive characterization of the homozygous M694V mutation associated phenotype, compared to the phenotypes of other FMF genotypes. For that aim, we compared between the demographic and clinical characteristics of 57 FMF patients, homozygous for the M694V MEFV mutation, and 56 patients with other MEFV genotypes. A questionnaire, detailing demographic and clinical features was completed for each patient based on an interview, physical examination and medical file data. Compared with the control group, the double M694V MEFV mutation group comprised more patients with severe disease (89.4 vs. 32.1%, p < 0.0001) and affected with FMF-related comorbidities (29.8 vs. 12.5%, p = 0.0373). The mean frequency of attacks per year was higher for patients with the double M694V MEFV mutation, before and during colchicine treatment (23.6 ± 9.3 vs.15.6 ± 11.7, p = 0.0001 and 7.2 ± 7.8 vs. 3.5 ± 5.5, p = 0.0007, respectively); and the mean dose of colchicine used was higher (1.9 ± 0.48 vs.1.48 ± 0.54 mg/day, p = 0.0001). Among the genotypes tested, homozygosity to the M694V MEFV mutation was found to be associated with the most grievous phenotype in the clinical spectrum of FMF.

Lack of clear and univocal genotype-phenotype correlation in familial Mediterranean fever patients: A systematic review

Familial Mediterranean fever (FMF) is the most common autosomal recessive autoinflammatory disease. To date, following the isolation of more than 280 MEFV sequence variants, the genotype-phenotype correlation in FMF patients has been intensively investigated; however, an univocal and clear consensus has not been yet reached. Thus, the aim of this systematic review was to analyze the available literature findings in order to provide to scientific community an indirect estimation of the impact of genetic factors on the phenotypic variability of FMF. This systematic review has been conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. The p.M694V mutation was reported to have a relatively severe clinical course, similarly, patients homozygous for M694I and M680I, or carrying a combination of both at codons 694 and 680, have a severe disease. Also, patients homozygous for M694V and V726A variants experienced more severe clinical picture. Conversely, heterozygous p.V726A and p.E148Q genotypes have been correlated with a milder disease course. At present, doubts remain on the potential pathogenic role of E148Q variant. The heterogenity in clinical FMF manifestations reflects the changes occuring in repertoire of mutations. We believe that clinical criteria and gene tests, enhancing each other, could better support the diagnosis of FMF.

Systemic amyloidosis with gastrointestinal involvement: Diagnosis from endoscopic and histological views

Amyloid tends to deposit in the gastrointestinal tract, which, being easily accessible, is often the target organ for a pathological diagnostic examination. Although a mucosal biopsy is necessary for a definitive diagnosis and several studies have reported positive results for each possible biopsy site, there remain many unclear features in various aspects. This review focuses on the current literature to determine a better understanding of the diagnosis from endoscopic and histological views in patients with systemic amyloidosis with gastrointestinal involvement. A literature search was performed using PubMed to identify relevant studies; linked references were also reviewed. Endoscopic findings vary based on the organ and the depositing amyloids. A fine granular appearance or polypoid protrusions are likely to occur in the duodenum. AL, Aβ2M, and ATTR amyloids are likely to deposit submucosally, while AA amyloid is easily deposited in the superficial layer of the mucous membrane. Furthermore, it is necessary to consider the collection of biopsy specimens from the duodenum, which has high positive biopsy rates. However, the difference in the positive biopsy rates depends on whether endoscopic findings are available or whether the appropriate number has not been fully elucidated. A duodenal biopsy is strongly recommended to confirm the deposition of amyloid in patients with systemic amyloidosis having gastrointestinal involvement. Because amyloidosis is a disease with a poor prognosis, early diagnosis and treatment are required; gastroenterologists and endoscopists play important roles.