The role of TNF-α and PAI-1 gene polymorphisms in familial Mediterranean fever

Clinical and molecular evaluation of MEFV gene variants in the Turkish population: a study by the National Genetics Consortium

Familial Mediterranean fever (FMF) is a monogenic autoinflammatory disorder with recurrent fever, abdominal pain, serositis, articular manifestations, erysipelas-like erythema, and renal complications as its main features. Caused by the mutations in the MEditerranean FeVer (MEFV) gene, it mainly affects people of Mediterranean descent with a higher incidence in the Turkish, Jewish, Arabic, and Armenian populations. As our understanding of FMF improves, it becomes clearer that we are facing with a more complex picture of FMF with respect to its pathogenesis, penetrance, variant type (gain-of-function vs. loss-of-function), and inheritance. In this study, MEFV gene analysis results and clinical findings of 27,504 patients from 35 universities and institutions in Turkey and Northern Cyprus are combined in an effort to provide a better insight into the genotype-phenotype correlation and how a specific variant contributes to certain clinical findings in FMF patients. Our results may help better understand this complex disease and how the genotype may sometimes contribute to phenotype. Unlike many studies in the literature, our study investigated a broader symptomatic spectrum and the relationship between the genotype and phenotype data. In this sense, we aimed to guide all clinicians and academicians who work in this field to better establish a comprehensive data set for the patients. One of the biggest messages of our study is that lack of uniformity in some clinical and demographic data of participants may become an obstacle in approaching FMF patients and understanding this complex disease.

Relationship of genetic factors with development of aortic dissection and aneurysm

Background

This study aims to investigate the relationship between the development of aortic dissections and aneurysms with the polymorphisms of angiotensin converting enzyme gene, methylenetetrahydrofolate reductase gene, plasminogen activator inhibitor-1 gene, and nitric oxide synthase gene.

Methods

Between April 2009 and July 2014, 38 patients with aortic dissections (28 males, 10 females; mean age 55.1±10.7 years; range, 30 to 78 years) and 67 patients with aortic aneurysms (57 males, 10 females; mean age 63.0±11.4 years; range, 31 to 82 years) were included in this cross-sectional study. The control group consisted of 60 healthy volunteers (41 males, 19 females; mean age 56.3±11.2 years; range, 30 to 82 years) without an aortic aneurysm or dissection, as assessed by thoracoabdominal computed tomography. The prespecified four genes were genotyped with competitive allelespecific polymerase chain reaction.

Results

The aortic dissection group had higher nitric oxide synthase-3 (4b/4b) expression levels, compared to the control group. The aortic aneurysm group had also higher nitric oxide synthase-3 (4b/4a) expression levels, compared to the control group. Compared to the control group, a higher rate of angiotensin converting enzyme I/D gene polymorphism was detected in the aneurysm group, while higher D/D polymorphism rates were found in the dissection group; although not statistically significant.

Conclusion

Our study results suggest that the nitric oxide synthase-3 intron 4b/4b and nitric oxide synthase-3 intron 4b/4a gene polymorphisms can be used as a predictor of aortic dissection and aneurysm development.

Does thiol-disulphide balance show oxidative stress in different MEFV mutations?

Many studies have shown that oxidative stress levels increase in patients with Familial Mediterranean Fever (FMF). Thiols are a class of compounds that include a sulfhydryl group (-SH) and can react with free oxygen radicals to protect tissues. We aimed to investigate thiol-disulphide homeostatic status in FMF patients and examined the effect of different mutations in the MEFV gene on the thiol-disulphide balance. We investigated thiol-disulphide parameters in patients with FMF and healthy controls. To determine the differential effect of MEFV gene mutations on thiol-disulphide balance, subjects were divided into five groups based on homozygous or compound heterozygous exon 10 and nonexon 10 mutations. Tests of thiol-disulphide homeostasis were conducted using the automated spectrophotometric method. Patients with FMF had significantly lower native thiol [433.8 µmol/l (243.3-536.4) vs. 484.1 µmol/L (340.2-612.3), p  < 0.001], total thiol levels [459.7 µmol/L (281.3-575.4) vs. 529.9 µmol/L (363-669.5), p < 0.001], and disulphide levels [14.0 µmol/l (2.7-33.3) vs. 24.4 µmol/l (7.2-36.6), p < 0.001] compared to the control group. Moreover, disulphide/native thiol (3.4 ± 1.7 vs. 4.7 ± 1.3, p < 0.001) and disulphide/total thiol (3.1 ± 1.4 vs. 4.3 ± 1.0 p < 0.001) were also detected lower in the FMF group compared to the control group. But the native thiol/total thiol ratios (93.6 ± 2.9 vs. 91.3 ± 2.1, p < 0.001) were higher in the FMF group. There was no significant difference between the native thiol, total thiol, and disulphide levels of individuals with nonexon 10 homozygous or compound heterozygous (Group 1), nonexon 10-exon 10 compound heterozygous (Group 2), exon 10 homozygous or compound heterozygous (Group 3), and heterozygous (Group 4) mutations. However, these parameters significantly differed from those of the healthy control group. Since no differences were found in our study between thiol and disulfide levels of Groups 1, 2 and 3, we believe that this rate cannot be shown as an indicator of oxidative damage in different mutations of FMFs. To the best of our knowledge, this study is the first study that demonstrates the effect of different FMF mutations on the thiol-disulphide balance.

Etiopathogenesis of Sheehan's Syndrome: Roles of Coagulation Factors and TNF-Alpha

Sheehan's Syndrome (SS) is defined as pituitary hormone deficiency due to ischemic infarction of the pituitary gland as a result of massive postpartum uterine hemorrhage. Herein, we aimed to investigate the roles of Factor II (G20210A), Factor V (G1691A), MTHFR (C677T and A1298C), PAI-1 4G/5G, and TNF- α (-308  G > A) gene polymorphisms in the etiopathogenesis of SS. Venous blood samples were obtained from 53 cases with SS and 43 healthy women. Standard methods were used to extract the genomic DNAs. Factor II (G20210A), Factor V (G1691A), and MTHFR (C677T and A1298C) polymorphisms were identified by real-time PCR. PAI-1 4G/5G and TNF- α (-308  G > A) gene polymorphisms were detected with polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) methods. According to statistical analysis, none of the polymorphisms were found to be significantly higher in the SS group compared to the control group. Hence, we suggest that genetic factors other than Factor II, Factor V, MTHFR, PAI-1, and TNF- α gene polymorphisms should be researched in the etiopathogenesis of SS.

Association of TNF-α -308 G > A and ACE I/D gene polymorphisms in hemodialysis patients with arteriovenous fistula thrombosis

PURPOSE

Tumor necrosis factor-α (TNF - α) -308 G > A promoter polymorphism seems to be associated with adverse clinical outcome in hemodialysis patients (HD). Angiotensin-converting enzyme (ACE) gene may be the causative factor contributing to the deterioration of renal functions. The aim of this study was to investigate the relationship between vascular access failure and the genetic polymorphisms of ACE and TNF-α gene.

METHODS

We enrolled and genotyped 47 HD patients with arteriovenous fistula (AVF) thrombosis, 51 HD patients without AVF thrombosis, and 40 healthy controls. The genotypes of these polymorphisms were determined by polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

The genotype distribution of TNF-α -308 G > A in patients with thrombosis was significantly different from the patients without thrombosis (p = 0.008). There was no significant difference between the two groups in terms of ACE I/D polymorphism (p = 0.213).

CONCLUSION

Our results propose that TNF-α -308 G > A genotype may be a potential genetic marker on HD patients with AVF thrombosis.

Is neutrophil/lymphocyte ratio associated with subclinical inflammation and amyloidosis in patients with familial Mediterranean fever?

Background. The purpose of the present study is to determine the association between neutrophil/lymphocyte ratio and both subclinical inflammation and amyloidosis in familial Mediterranean fever. Methods. Ninety-four patients with familial Mediterranean fever and 60 healthy volunteers were included in the study. Of the patients, 12 had familial Mediterranean fever related amyloidosis. The neutrophil/lymphocyte ratio of the patients was obtained from the hematology laboratory archive. Results. The neutrophil/lymphocyte ratio was significantly higher among persons with familial Mediterranean fever compared to healthy individuals (P < 0.0001). Also, neutrophil/lymphocyte ratio was significantly higher in patients with amyloidosis than in amyloidosis-free patients (P < 0.0001). Since NLR was evaluated in nonamyloid and amyloid stages of the same patient population (type 1 phenotype), we obtained significant statistical differences (1.95 ± 0.30 versus 2.64 ± 0.48, P < 0.05, resp.). With the cutoff value of neutrophil/lymphocyte ratio >2.21 and AUC = 0.734 (P = 0.009), it was a reliable marker in predicting the development of amyloidosis. Conclusion. The neutrophil/lymphocyte ratio, an emerging marker of inflammation, is higher in patients with familial Mediterranean fever in attack-free periods. The neutrophil/lymphocyte ratio may be a useful marker in predicting the development of amyloidosis.