Atypical Familial Mediterranean Fever Research Articles

Unprecedented Coexistence of Autoinflammatory Myositis and Chronic Thrombosis with heterozygotic M694V mutation: An atypical presentation of Familial Mediterranean Fever.

Familial Mediterranean Fever (FMF) is a hereditary autoinflammatory disorder predominantly characterized by periodic fever, abdominal pain, and joint manifestations. It can exhibit various atypical presentations and affects individuals globally. However, cases of FMF concurrently presenting with chronic thrombosis and myositis have not been previously reported. A 41-year-old male presented with alternating severe bilateral leg pain, stiffness, and localized swellings without fever or abdominal symptoms. His history included recurrent inflammatory joint pain treated with prednisolone. Physical examination revealed leg pain, limited ankle joint movement, and tender swellings in thighs, forearms, and feet. Collateral abdominal veins were also observed. Unresponsive to prednisolone and colchicine, the patient underwent MRI, revealing muscle inflammation in both legs and thighs and chronic thrombosis in the infrarenal inferior vena cava. Genetic testing confirmed the heterozygotic M694V mutation, diagnosing an atypical FMF. Anakinra treatment led to substantial clinical and laboratory improvement. Although FMF diagnosis typically relies on characteristic clinical features and genetic analysis, atypical presentations challenge established criteria. This case uniquely showcases coexisting myositis and chronic thrombosis in FMF. Myalgia is common in FMF, with M694V mutation associated with severe muscular symptoms. The lack of fever and myositis findings differentiate our case from protracted febrile myalgia syndrome. FMF's chronic inflammatory state is known to influence thrombosis risk, and our findings align with this association. Chronic thromboembolism and myositis together signify an unusual clinical presentation of FMF. This case highlights the potential for FMF to present with complex manifestations beyond the conventional symptoms. Myositis and vascular involvement should prompt consideration of FMF diagnosis when combined with patient history, clinical features, and laboratory results. These rare associations underscore the need for further research to enhance understanding of FMF's diverse clinical spectrum.

A case of Behçet's-like disease associated with trisomy 8-positive myelodysplastic syndrome presented periodic fever with MEFV E148Q variant.

Behçet's-like disease, which incompletely fulfils the criteria of Behçet's disease, is often associated with trisomy 8-positive myelodysplastic syndrome (MDS). We report a case of an 82-year-old man with these conditions carrying E148Q variant of MEFV gene who presented with periodic fever. The patient presented with joint pain, muscle pain, and episodes of periodic fever every two weeks for the past three months. On admission, painful erythema and fever were observed. Colonoscopy revealed erosion in the cecum and ascending colon. The patient had bicytopenia, and a bone marrow biopsy showed findings compatible with trisomy 8-positive unclassifiable MDS. Because the patient incompletely fulfilled the criteria for Behçet's disease, he was diagnosed with Behçet's-like disease associated with trisomy 8-positive MDS. Positron emission tomography-computed tomography performed during the fever revealed multiple muscle lesions consistent with the sites of pain. To examine the cause of the periodic fever attacks, MEFV gene was analysed, and the results revealed E148Q variant. Steroids were ineffective against periodic fever attacks. A daily dose of 0.5 mg colchicine was prescribed, but the effect was minimal, probably because of the insufficient dose due to renal dysfunction. Based on the diagnosis of atypical familial Mediterranean fever, canakinumab was added, which partially mitigated the periodic fever. This case suggests the importance of ruling out MDS when physicians see an elderly patient who present with Behçet-like disease. Although the significance of E148Q variant in the pathogenesis of periodic fever remains controversial, it may act as a disease modifier in accordance with trisomy 8-positive MDS.

Investigation of Neutrophil Extracellular Trap (NET) Induction in Patients with Chronic Idiopathic Neutropenia Bearing Mutations in the Mediterranean Fever (MEFV) Gene

Introduction: Chronic idiopathic neutropenia (CIN) is a disorder characterized by the prolonged and unexplained reduction in the number of circulating neutrophils. The pathophysiology of CIN has been associated with an inflammatory bone marrow microenvironment consisting of activated T-cells with an oligoclonal/monoclonal profile and intermediate CD14bright/CD16+ monocytes that induce the apoptotic death of the granulocytic progenitor cells. To probe further the basis of immune cell activation in CIN we have recently investigated by next generation sequencing (NGS) the frequency of mutations in the MEFV gene encoding pyrin, in a cohort of 50 CIN patients without any signs/symptoms of Familial Mediterranean Fever (FMF). We have found that 9/50 patients displayed variants associated with typical or atypical FMF phenotype in the Greek population implicating exon 10 and/or exon 2 (Skendros P et al. Blood, 138, Sup.1, p3124;2021). Aim:MEFV mutations have been associated with increased neutrophil activation in FMF and other inflammatory diseases, neutrophil entry in autophagy and extrusion of Neutrophil Extracellular Traps (NETs) decorated with the pro-inflammatory cytokine IL-1β. The aim of the current study is to investigate the association between MEFV mutations and NET formation in neutrophils of CIN patients. Patients-Methods: We studied 20 CIN patients (17 females and 3 males) aged 27 to 78 years. Six CIN patients harbored at least one MEFV mutation with potential clinical significance (A744S homo/R202Q homo, I720M hetero, R202Q homo, K965R hetero, A744S hetero, M694V hetero) and 14 were negative for MEFV pathogenic mutations. The MEFV R202Q mutation is located in exon 2 whereas all the rest mutations are located in exon 10. We isolated neutrophils from healthy subjects (n=5), age- and sex- matched with the patients, and co-cultured them with serum from CIN patients. We used the supernatants of the cultures to quantify NETs with Sytox green staining for extracellular DNA and/or ELISA for dsDNA/MPO complexes. We also used the serum-treated neutrophils for the evaluation of NETosis by immunostaining using confocal microscopy. In addition, neutrophils isolated from CIN patients were used to detect their direct response to spontaneous NETosis induction. Statistical analysis was performed with one-way ANOVA adjusting for multiple comparisons. Results: By co-culturing patients' sera with healthy neutrophils obtained from five different healthy donors, we did not identify statistically significant differences in NETosis evaluation between the three study groups i.e. CIN patients with MEFV mutations, CIN patients negative for pathogenic MEFV mutations, and healthy individuals. On an individual basis, the patient harboring the double homozygous MEFV mutations (A744S/R202Q) displayed increased NETosis in immunostaining, Sytox and ELISA evaluation, as compared to MEFV unmutated CIN patients and healthy individuals. In addition, ex vivo culture of patients' neutrophils and microscopic observation gave us the indication that CIN patients, regardless of their MEFV gene variants, present increased NETosis compared to healthy individuals, suggesting an overactivation status of neutrophils in CIN. Conclusions: The neutrophils of CIN patients display increased NETosis irrespectively of the MEFV mutation status and may thus contribute to the inflammatory processes associated with the disease, a field that has not been investigated so far. Although in our study MEFV mutations did not appear to contribute significantly to inflammatory processes through the NETosis mechanism in CIN patients, their involvement in other aspects of immune deregulation such as through the mTOR/autophagy pathway remains to be further explored.

Autoinflammatory syndromes with coexisting variants in Mediterranean FeVer and other genes: Utility of multiple gene screening and the possible impact of gene dosage

ObjectiveTo assess the possible impact conferred by co-existing variants in MEditerranean FeVer (MEFV) and other genes on systemic autoinflammatory disease (SAID) phenotype. MethodsConsecutive patients (n = 42) who underwent screening for SAIDs by next generation sequencing (NGS) targeting 26 genes, and carried at least one MEFV gene variant, were retrospectively studied. A total of 63 MEFV gene variants mainly located in exon 10 (n = 29) and exon 2 (n = 19) were identified in 21 patients with juvenile- and 21 with adult-onset disease. ResultsThe candidate clinical diagnosis was Familial Mediterranean Fever (FMF) in 11, polygenic SAIDs (PFAPA, Still's disease, atypical SAPHO and inflammatory bowel disease) in 9, whereas the disease could not be clinically defined in 22 patients. Notably, 33 out of the 42 patients (79%) had at least one co-existing variants in 19 genes other than MEFV. NGS confirmed all clinical diagnoses and helped defining diagnosis in 59% of the remaining cases. Patients with undefined SAIDs (n = 9) or atypical FMF phenotype (n = 12) carried significantly more disease-causing variants in genes other than MEFV compared to patients with typical FMF (n = 9). More than one variants in these genes were significantly associated with adult-onset disease, while disease–causing variants in the same genes were also associated with an overall more severe SAID phenotype. ConclusionCo-existing variants in SAID-related genes may explain the phenotypic variability of these diseases. Further studies should validate combined molecular and clinical data in order to better understand the cumulative gene dosage effect and improve the classification of these patients.

Clinical and Genetic Analysis of 22 Japanese Patients with Familial Mediterranean Fever: An Examination of MEFV and 10 Other Genes Related to Autoinflammatory Syndromes.

Objective Familial Mediterranean Fever (FMF) is the most frequent autoinflammatory syndrome, and its frequency is reported to be increasing in Japan. We studied the clinical features and genetic background of patients with FMF in our hospital. Methods We analyzed the clinical features and genomic variants of MEFV, as well as 10 genes related to other autoinflammatory syndromes, in 22 Japanese patients with FMF. A genetic analysis was performed with a next generation sequencer. Results The patients were classified into the typical FMF (n=16) and atypical FMF (n=6) groups. Fever, abdominal pain, thoracic pain, and arthralgia were observed in 22, 12, 8, and 10 patients, respectively. MEFV variants were found in 19 patients (86.4%). Two cases had no MEFV variants and one case only had a variant in the 3′ untranslated region (3′-UTR) of MEFV. Genomic variants were found in genes other than MEFV in 7 patients (31.8%); however, none met the diagnostic criteria for autoinflammatory syndromes with disease-related gene variants, and all were classified as typical FMF. Moreover, none of the 6 patients with atypical FMF had any variants among the 10 disease-related genes. All cases in which the onset occurred before 20 years of age were classified as typical FMF. Conclusion The clinical features of FMF recorded in our hospital coincided with those from the Japanese national epidemiological survey of FMF in Japan. More than 30% of the patients with FMF had non-MEFV genes, related to other autoinflammatory syndromes, thereby suggesting that variants of these genes may act as a disease-modifier in FMF.

Atypical Familial Mediterranean Fever Complicated with Gastrointestinal Amyloidosis Diagnosed due to Paroxysmal Arthralgia and Intractable Diarrhea, Successfully Treated with Tocilizumab

A 53-year-old man with recurrent episodes of large joint pain and a low-grade fever at irregular intervals for 16 years developed right knee and ankle arthralgia, watery diarrhea, and abdominal pain. Following an ileum and colon biopsy, he was diagnosed with gastrointestinal amyloidosis. We suspected familial Mediterranean fever (FMF) based on his history and administered colchicine; his symptoms subsequently improved. Thus, he was diagnosed with atypical FMF. After tocilizumab administration, the amyloid deposits disappeared. This case suggests that physicians should consider FMF even in cases with atypical symptoms in order to prevent the progression of amyloidosis and that amyloid deposits can be eliminated by interleukin (IL)-6 inhibition.

Atypical type of familial Mediterranean fever: An underdiagnosed cause of chronic aseptic meningitis.

We report an atypical case of familial Mediterranean fever (FMF) concomitant with chronic aseptic meningitis. The patient experienced fever, abdominal and back pain because of serositis, and headache because of aseptic meningitis for 4 weeks. Blood examinations revealed increased white blood cells and serum amyloid A level. Medications, including steroids, did not improve his symptoms. However, the patient experienced immediate relief after the administration of colchicine. We diagnosed him as having atypical FMF based on the symptoms, especially positive response to colchicine, and heterozygous mutations on exon2 and 5 (E148Q/S503C) in MEFV gene. Unlike typical FMF, a cause of recurrent aseptic meningitis, atypical FMF might be an underdiagnosed cause of chronic aseptic meningitis.

Familial Mediterranean Fever

Familial Mediterranean fever (FMF) is an autoinflammatory disease caused by MEditerranean FeVer gene (MEFV) mutations. In Japan, patients with FMF have been previously reported, including a mild or incomplete form. Several factors are presumed to contribute to the variable penetrance and to the phenotypic variability of FMF. We conducted the current study to investigate the correlation of variable clinical presentations and MEFV genotypic distributions in Japanese FMF patients.We analyzed demographic, clinical, and genetic data for 311 FMF patients enrolled in the study. Clinically, we classified FMF into 2 phenotypes: 1) the “typical” form of FMF, and 2) the “atypical” form of FMF according to the Tel Hashomer criteria. Patients with the typical FMF phenotype had a higher frequency of febrile episodes, a shorter duration of febrile attacks, more frequent thoracic pain, abdominal pain, a family history of FMF, and MEFV exon 10 mutations. Conversely, patients with the atypical FMF phenotype had a lower frequency of fever episodes and more frequent arthritis in atypical distribution, myalgia, and MEFV exon 3 mutations. Multivariate analysis showed that the variable associated with typical FMF presentation was the presence of MEFV exon 10 mutations. Typical FMF phenotype frequencies were decreased in patients carrying 2 or a single low-penetrance mutations compared with those carrying 2 or a single high-penetrance mutations (M694I), with an opposite trend for the atypical FMF phenotype. In addition, patients having more than 2 MEFV mutations had a younger disease onset and a higher prevalence of thoracic pain than those carrying a single or no mutations. Thus, MEFV exon 10 mutations are associated with the more typical FMF phenotype. In contrast, more than half of the Japanese FMF patients without MEFV exon 10 mutations presented with an atypical FMF phenotype, indicating that Japanese FMF patients tend to be divided into 2 phenotypes by a variation of MEFV mutations.

The MEFV mutations and their clinical correlations in children with familial Mediterranean fever in southeast Turkey

The aim of this study was to determine the Mediterranean fever (MEFV) gene mutations and their clinical correlations in children with familial Mediterranean fever (FMF) in southeast Turkey. Clinical and laboratory characteristics of 147 (65 males, 82 females) consecutive children with FMF having a positive MEFV gene mutation were prospectively investigated. Patients with negative MEFV gene mutations or atypical FMF presentations and those from other regions of the country were excluded. Clinical manifestations and disease severity scores were recorded. The six most frequent MEFV mutations including M694V, V726A, R726H, P369S, E148Q and P369S were investigated by a reverse hybridization test method. The median age of study group was 9.0years, median age at diagnosis was 7.8years, median age at disease onset was 5.0years, and median follow-up duration was 4.0years. A positive family history of FMF and parent-to-offspring transmission was found in 58.5 and 42.2% of families, respectively. The frequencies of independent alleles, with decreasing order, were E148Q (30.7%), M694V (26.0%), R761H (13.5%), V726A (13.0%), P369S (10.5%) and M680I (6.3%) in FMF patients. The M694V subgroup had higher mean disease severity score and longer attack duration compared with E148Q and other mutations subgroups (p<0.05). Two patients with amyloidosis had the M694V homozygote genotype. In conclusion contrast to other regions and many other ethnicities of the world, the most frequent MEFV gene mutation was E148Q in southeast Turkey. The M694V mutation frequency was lower, and disease severity was relatively mild in FMF children of this region.

An Atypical Familial Mediterranean Fever Patient Who Developed Ulcers in the Terminal Ileum and Recurrent Abscess-like Lesions in Multiple Organs

We herein describe the case of a 25-year-old woman who suffered from atypical familial Mediterranean fever for more than a decade. She presented with a periodic fever, abdominal pain and persistent ulcers in the terminal ileum. Colchicine was effective, and familial Mediterranean fever was diagnosed. A genetic study showed a heterozygous E148Q mutation in the MEFV gene. Multiple, recurrent, abscess-like lesions developed asynchronously in the spleen, liver, and a lung. Infliximab was administered when colchicine treatment became ineffective. However, infliximab treatment soon became ineffective, probably because antibodies were generated against it. Therefore, etanercept treatment was started, and the patient showed an immediate response.