Israel Medical Association Journal

Background: Postpericardiotomy syndrome (PPS) is characterized by pleuro-pericardial inflammation, which occurs in patients undergoing surgical procedures involving the pleura, pericardium, or both. The syndrome is considered to be immune mediated. However, its pathogenesis is not fully understood. It has previously been demonstrated that the Mediterranean Fever (MEFV) gene, which is associated with familial Mediterranean fever (FMF), has a role in the activation and expression of several inflammatory diseases.

Objectives: To investigate whether carriage of the MEFV mutation may precipitate PPS or affect its phenotype.

Methods: The study population included 45 patients who underwent cardiac surgery and developed PPS. The control group was comprised of 41 patients who did not develop PPS. Clinical and demographic data was collected. The severity of PPS was evaluated. Genetic analysis to determine the carriage of one the three most common MEFV gene mutations (M694V, V726A, E148Q) was performed. The carriage rate of MEFV mutations in patients with and without PPS was compared. Association between MEFV mutation carriage and severity of PPS was evaluated. 

Results: The rate of mutation carriage in the MEFV gene was similar in patients with and without PPS (15.6% in the study groups vs. 29.3% in the control group, P = 0.1937). The rate of mutation carriage in the MEFV gene was significantly lower among patients with severe PPS as compared to patients with mild-moderate PPS (4.8% vs. 25%, P < 0.05).

Conclusions: Carriage of mutations in the MEFV gene is not associated with development of PPS; however, it may affect PPS severity.

 

Background: Familial Mediterranean fever (FMF) is a recessively inherited disease with a variety of clinical presentations. The disease is associated with mutations in the FMF gene (MEFV), which encodes for the pyrin protein. The role of the E148Q pyrin mutation in the FMF phenotype remains inconclusive, and some authors even view it as a disease-insignificant polymorphism. The calculated change, imposed by this mutation on pyrin structure, may help to understand the role of this mutation

Objectives: To calculate the relative electrochemical effect of the E148Q mutation on the structure of pyrin protein.

Methods: The electronic properties of the wild-type pyrin molecule and its common mutated forms were computed for the full-length molecule and its segments, encoded by exons 2 and 10, using the HyperChem 7.5 program with one of the molecular mechanical methods (MM+). The change in the structure of the molecule, expressed as a change in energy gain, conferred by the mutations was determined.

Results: The E148Q mutation caused deviation from the wild-type pyrin segment encoded by exon 2 by 1.15% and from the whole pyrin molecule by 0.75%, comparable to the R202Q mutation and less than the M694V mutation which caused a deviation from the wild-type structure of the whole pyrin molecule by 1.5%.

Conclusions: A quantum-chemistry based model suggests that the structural effect of the E148Q mutation is indeed low, but not zero. 
 

Background: Since the identification of the MEFV gene 198 mutations have been identified, not all of which are pathologic. The screening methods used in Israel to test patients suspected of having FMF include a kit that tests for the five main mutations (M694V, V726A, M680Ic/g, M694I, E148Q), and the sequencing of MEFV exon 10 in combination with restriction analysis for detecting additional mutations.

Objectives: To determine the contribution of testing for five additional mutations – A744S, K695R, M680Ic/t, R761H and P369S – to the molecular diagnosis of patients clinically suspected of having FMF.

Methods: A total of 1637 patients were tested for FMF mutations by sequencing exon 10 and performing restriction analysis for mutations E148Q and P369S.

Results: Nearly half the patients (812, 49.6%) did not have any detectable mutations, 581 (35.5%) had one mutation, 241 (14.7%) had two mutations, of whom 122 were homozygous and 119 compound heterozygous, and 3 had three mutations. Testing for the additional five mutations enabled us to identify 46 patients who would have been missed by the molecular diagnosis kit and 22 patients who would have been found to have only one mutation. Altogether, 4.3% of the patients would not have been diagnosed correctly by using only the kit that tests for the five main mutations.

Conclusions: This study suggests that testing for the additional five mutations as well as the five main mutations in patients with a clinical presentation of FMF adds significantly to the molecular diagnosis of FMF in the Israeli population.
 

Background: Familial Mediterranean fever is an autosomal recessive disease characterized by recurrent attacks of fever and serositis. The disease is caused by mutations in the MEFV gene, presumed to act as a down-regulator of inflammation within the polymorphonuclear cells.

Objectives: To present the results of 412 FMF patients genotyped for three MEFV mutations, M694V, V726A and E148Q.

Results: The most frequent mutation, M694V, was detected in 47% of the carrier chromosomes. This mutation, especially common among North African Jewish FMF[1] patients, was not found in any of the Ashkenazi (East European origin) patients. Overall, one of the three mutations was detected in 70% of the carrier chromosomes. M694V/M694V was the most common genotype (27%), followed by M694V/V726A (16%). The full genotype could be assessed in 57% of the patients, and one disease-causing mutation in an additional 26%. Only one patient with the E148Q/E148Q genotype was detected despite a high carrier rate for this mutation in the Jewish population, a finding consistent with a low penetrance of this genotype. The M694V/M694V genotype was observed in 15 patients with amyloidosis compared to 4 amyloidosis patients with other genotypes (P < 0.0001).

Conclusions: Because of low penetrance and as yet other undetermined reasons, mutation analysis of the most common MEFV mutations supports a clinical diagnosis in only about 60% of patients with definite FMF.

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Background: Familial Mediterranean fever is an autosomal recessive disease characterized by sporadic attacks of inflammation affecting the serosal spaces. The gene associated with FMF[1] (MEFV), mainly expressed in neutrophils, was recently found to be expressed also in primary cultures of serosal origin (peritoneal and synovial fibroblasts). A C5a inhibitor, previously detected in normal serosal fluids, was recently identified in serosal cultures as well, and was found to be deficient in serosal fluids and cultures obtained from FMF patients.

Objective: To investigate the effect of colchicine (the main therapeutic agent for FMF patients) and certain inflammatory cytokines (IL-1b, TNF-a, IFN-a, IFN-g) on MEFV expression and C5a inhibitor activity in neutrophils and primary peritoneal fibroblast cultures.

Methods: Human primary peritoneal fibroblast cultures and neutrophils were studied for MEFV expression and C5a inhibitor activity, using reverse transcription-polymerase chain reaction and C5a-induced myeloperoxidase assay, respectively, in the presence and absence of colchicine and cytokines.

Results: MEFV expression in neutrophils was high and could not be induced further. Its expression in the peritoneal fibroblasts was lower than in neutrophils and could be induced using colchicine and cytokines parallel with induction of C5a inhibitor activity. Semi-quantitative RT-PCR[2] assays enabled estimation of MEFV induction by the cytokines at 10–100-fold and could not be further increased by concomitant addition of colchicine.

Conclusion: Serosal tissues, which are afflicted in FMF, express colchicine and cytokine-inducible MEFV and contain inducible C5a inhibitor activity. The relation between colchicine ability to induce MEFV and C5a inhibitor activity, and its efficacy in FMF treatment, require further investigation.

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[1] RT-PCR = reverse transcription-polymerase chain reaction

[2] FMF = familial Mediterranean fever

Background: Familial Mediterranean fever is a genetic disease in which some characteristic gene mutation have been found.

Objective: To analyze the phenotype-genotype correlations in North African Jews and Armedians with FMF.

Methods: We studied MEFV gene mutations and phenotype-genotype correlations in North African Jews and Armedians with Familial Mediterranean Fever living in France.

Results: M694V mutation was the most common mutation in Jews and in Armenians. Patients with M6801 homozygosity or M6801/M694V compound heterozygosity had a phenotype as severe as patients with M694V homozygosity.

Conclusions: This study characterizes the phenotype-genotype in specific ethnic groups of patients with FMF.