A comprehensive analysis of 12 thrombophilic mutations and related parameters in patients with inflammatory bowel disease: data from Turkey

Cholesterol transport and beyond: Illuminating the versatile functions of HDL apolipoproteins through structural insights and functional implications

High-density lipoproteins (HDLs) play a vital role in lipid metabolism and cardiovascular health, as they are intricately involved in cholesterol transport and inflammation modulation. The proteome of HDL particles is indeed complex and distinct from other components in the bloodstream. Proteomics studies have identified nearly 285 different proteins associated with HDL; however, this review focuses more on the 15 or so traditionally named "apo" lipoproteins. Important lipid metabolizing enzymes closely working with the apolipoproteins are also discussed. Apolipoproteins stand out for their integral role in HDL stability, structure, function, and metabolism. The unique structure and functions of each apolipoprotein influence important processes such as inflammation regulation and lipid metabolism. These interactions also shape the stability and performance of HDL particles. HDLs apolipoproteins have multifaceted roles beyond cardiovascular diseases (CVDs) and are involved in various physiological processes and disease states. Therefore, a detailed exploration of these apolipoproteins can offer valuable insights into potential diagnostic markers and therapeutic targets. This comprehensive review article aims to provide an in-depth understanding of HDL apolipoproteins, highlighting their distinct structures, functions, and contributions to various physiological processes. Exploiting this knowledge holds great potential for improving HDL function, enhancing cholesterol efflux, and modulating inflammatory processes, ultimately benefiting individuals by limiting the risks associated with CVDs and other inflammation-based pathologies. Understanding the nature of all 15 apolipoproteins expands our knowledge of HDL metabolism, sheds light on their pathological implications, and paves the way for advancements in the diagnosis, prevention, and treatment of lipid and inflammatory-related disorders.

Association of serum lipids with inflammatory bowel disease: a systematic review and meta-analysis

Background

Serum lipid levels seem to be abnormal in Inflammatory bowel disease (IBD). However, the specific manifestation of abnormal serum lipid levels in IBD are heterogeneous among studies and have not been sufficiently determined yet.

Methods

PubMed, EMBASE, and Cochrane Library databases were searched. Serum lipid levels were compared between IBD patients and Health individuals, Crohn's (CD) and ulcerative colitis (UC), active and inactive, mild and non-mild patients, respectively. Meta-analyses were performed by using a random-effect model. Weight mean difference (WMD) with 95% confidence intervals (CIs) were calculated.

Results

Overall, 53 studies were included. Compared with healthy controls, IBD patients had significantly lower TC (WMD = -0.506, 95%CI = -0.674 to -0.338, p < 0.001), HDL-c (WMD = -0.122, 95%CI = -0.205 to -0.039, p = 0.004), and LDL-c (WMD = -0.371, 95%CI = -0.547 to -0.194, p < 0.001) levels. CD groups had a significantly lower TC (WMD = -0.349, 95%CI = -0.528 to -0.170, p < 0.0001) level as compared to UC groups. Active IBD and non-mild UC groups had significantly lower TC (WMD = -0.454, 95%CI = -0.722 to -0.187, p = 0.001) (WMD =0.462, 95%CI = 0.176 to 0.748, p = 0.002) and LDL-c (WMD = -0.225, 95%CI = -0.445 to -0.005, p = 0.045) (WMD =0.346, 95%CI = 0.084-0.609, p = 0.010) levels as compared to inactive IBD and mild UC groups, respectively.

Conclusion

The overall level of serum lipids in IBD patients is lower than that of healthy individuals and is negatively associated with disease severity.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022383885.

The methylenetetrahydrofolate reductase 1298 A>C polymorphism is associated with an increased risk of inflammatory bowel disease: evidence from a meta-analysis

OBJECTIVE

The association between genetic variants in methylenetetrahydrofolate reductase (MTHFR) and risk for inflammatory bowel disease (IBD) has been widely studied. However, the results are equivocal. In this meta-analysis, we aimed to determine the association between MTHFR polymorphisms and susceptibility to IBD.

METHODS

We retrieved studies from the PubMed, Web of Science, Ovid, and China National Knowledge Infrastructure databases. Data were analyzed using STATA software; odds ratios (OR) and confidence intervals (CI) were calculated using fixed or random effects models.

RESULTS

A marginally significant association of the MTHFR 677 C > T polymorphism and patients' IBD risk was observed in the overall analysis (OR = 1.11, 95% CI, 1.01-1.23), but not in the analysis of high-quality studies. However, for the MTHFR 1298 A > C polymorphism, a significant association was found between the MTHFR 1298 AC/CC genotypes and IBD risk in the overall analysis (OR = 1.26, 95% CI, 1.10-1.44), in the high-quality studies (OR = 1.20, 95% CI, 1.02-1.41), and in patients with ulcerative colitis (OR = 1.28, 95% CI, 1.10-1.48).

CONCLUSIONS

Evidence from this meta-analysis indicates that the MTHFR 1298 A > C polymorphism may be responsible for susceptibility to IBD and ulcerative colitis.

Experimental and Clinical Evidence of Endothelial Dysfunction in Inflammatory Bowel Disease

The endothelium has a crucial role in proper hemodynamics. Inflammatory bowel disease (IBD) is mainly a chronic inflammatory condition of the gastrointestinal tract. However, considerable evidence points to high cardiovascular risk in patients with IBD. This review positions the basic mechanisms of endothelial dysfunction in the IBD setting (both clinical and experimental). Furthermore, we review the main effects of drugs used to treat IBD in endothelial (dys)function. Moreover, we leave challenging points for enlarging the therapeutic arsenal for IBD with new or repurposed drugs that target endothelial dysfunction besides inflammation.

The association of the MTHFR C677T polymorphism with inflammatory bowel diseases in the Israeli Jewish population: An example of genetic heterogeneity

MTHFR C677T is a common gene polymorphism that has been shown to be associated with hyperhomocysteinemia. Studies on the role of MTHFR in inflammatory bowel diseases (IBD) have yielded conflicting results, perhaps due in part to genetic heterogeneity. The prevalence of the MTHFR C677T variant allele varies according to Jewish subpopulations: Ashkenazi vs non-Ashkenazi. The aim of this study was to examine the association between MTHFR C677T genotype and IBD in the different Jewish populations.DNA samples were assessed for the presence of the MTHFR C677T variant allele in 445 Jewish Israeli IBD patients: 338 with Crohn's disease [CD] (214 Ashkenazi and 124 non-Ashkenazi Jews) and 107 with ulcerative colitis [UC] (73 Ashkenazi and 34 non-Ashkenazi Jews), and in 347 healthy controls: 173 Ashkenazi and 174 Non-Ashkenazi Jews. Possible genotype-phenotype associations were investigated.We showed a significantly higher frequency of MTHFR 677T variant genotypes in non-Ashkenazi CD patients: Odds ratio of 1.86 for heterozygotes (CT) and 2.89 for homozygotes (TT) compared to non-Ashkenazi healthy controls. No significant association was found for UC in non-Ashkenazi patients or for CD or UC in Ashkenazi patients.Our findings suggest that the MTHFR 677T variant may contribute to the risk of CD in non-Ashkenazi but not Ashkenazi Jews. This may result from genetic heterogeneity and highlights the complexity of the genetic etiology of IBD.

Polymorphisms of glutathione S-transferase and methylenetetrahydrofolate reductase genes in Moldavian patients with ulcerative colitis: Genotype-phenotype correlation

Background

Glutathione S-transferases (GSTM1, GSTT1, and GSTP1) and methylenetetrahydrofolate reductase (MTHFR) are important enzymes for protection against oxidative stress. In addition, MTHFR has an essential role in DNA synthesis, repair, and methylation. Their polymorphisms have been implicated in the pathogenesis of ulcerative colitis (UC). The aim of the present study was to investigate the role of selected polymorphisms in these genes in the development of UC in the Moldavian population.

Methods

In a case-control study including 128 UC patients and 136 healthy individuals, GSTM1 and GSTT1 genotypes (polymorphic deletions) were determined using multiplex polymerase chain reaction (PCR). The GSTP1 rs1695 (Ile105Val), MTHFR rs1801133 (C677T), and MTHFR rs1801131 (A1298C) polymorphisms were studied with restriction fragment length polymorphism (RFLP) analysis. Genotype–phenotype correlations were examined using logistic regression analysis.

Results

None of the genotypes, either alone or in combination, showed a strong association with UC. The case-only sub-phenotypic association analysis showed an association of the MTHFR rs1801133 polymorphism with the extent of UC under co-dominant (p corrected = 0.040) and recessive (p corrected = 0.020; OR = 0.15; CI = 0.04–0.63) genetic models. Also, an association between the MTHFR rs1801131 polymorphism and the severity of UC was reported for the over-dominant model (p corrected = 0.023; coefficient = 0.32; 95% CI = 0.10–0.54).

Conclusion

The GST and MTHFR genotypes do not seem to be a relevant risk factor for UC in our sample. There was, however, evidence that variants in MTHFR may influence the clinical features in UC patients. Additional larger studies investigating the relationship between GST and MTHFR polymorphisms and UC are required.

Increased risk of venous thromboembolic events with corticosteroid vs biologic therapy for inflammatory bowel disease

BACKGROUND & AIMS

We investigated whether treatment of active inflammatory bowel disease with biologic agents is associated with a reduced risk of venous thromboembolic events (VTEs) compared with corticosteroid therapy.

METHODS

We performed a retrospective analysis of 15,100 adults with inflammatory bowel disease who were identified from the Truven Health MarketScan databases. We analyzed data from patients who received 6 months of continuous medical and prescription coverage before and 12 months after their first diagnosis and had no VTE during the 6 months before they first received biologic or corticosteroid therapy. The outcome assessed was any VTE that occurred during the 12-month follow-up period. A multivariate logistic regression model was used to evaluate the effects of biologic, corticosteroid, and combination therapies (biologics and corticosteroids) on VTE risk.

RESULTS

Three hundred twenty-five VTEs occurred during the study period (in 2.25% of patients receiving only corticosteroids, in 0.44% of patients receiving biologics, and in 2.49% of patients receiving combination therapy). Compared with patients receiving only corticosteroids, the odds ratio for VTE in patients receiving only biologics was 0.21 (95% confidence interval, 0.05-0.87) in the multivariate model, and the odds ratio for VTE in patients on combination therapy was 1.01.

CONCLUSIONS

Compared with treatment with only a biologic agent, corticosteroid therapy is associated with a nearly 5-fold increase in risk for VTE. Combination therapy with corticosteroids and biologic agents was associated with the same risk for VTE as that of corticosteroids alone. Corticosteroids therefore appear to increase risk for VTE.

Venous thrombosis and prothrombotic factors in inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) may have an increased risk of venous thrombosis (VTE). PubMed, ISI Web of Knowledge and Scopus were searched to identify studies investigating the risk of VTE and the prevalence of acquired and genetic VTE risk factors and prothrombotic abnormalities in IBD. Overall, IBD patients have a two- to fourfold increased risk of VTE compared with healthy controls, with an overall incidence rate of 1%-8%. The majority of studies did not show significant differences in the risk of VTE between Crohn’s disease and ulcerative colitis. Several acquired factors are responsible for the increased risk of VTE in IBD: inflammatory activity, hospitalisation, surgery, pregnancy, disease phenotype (e.g., fistulising disease, colonic involvement and extensive involvement) and drug therapy (mainly steroids). There is also convincing evidence from basic science and from clinical and epidemiological studies that IBD is associated with several prothrombotic abnormalities, including initiation of the coagulation system, downregulation of natural anticoagulant mechanisms, impairment of fibrinolysis, increased platelet count and reactivity and dysfunction of the endothelium. Classical genetic alterations are not generally found more often in IBD patients than in non-IBD patients, suggesting that genetics does not explain the greater risk of VTE in these patients. IBD VTE may have clinical specificities, namely an earlier first episode of VTE in life, high recurrence rate, decreased efficacy of some drugs in preventing further episodes and poor prognosis. Clinicians should be aware of these risks, and adequate prophylactic actions should be taken in patients who have disease activity, are hospitalised, are submitted to surgery or are undergoing treatment.

Consensus statements on the risk, prevention, and treatment of venous thromboembolism in inflammatory bowel disease: Canadian Association of Gastroenterology

BACKGROUND & AIMS

Guidelines for the management of venous thromboembolism (VTE) from the American College of Chest Physicians do not address patients with inflammatory bowel disease (IBD), a group with a high risk of both VTE and gastrointestinal bleeding. We present recommendations for the prevention and treatment of VTE in patients with IBD.

METHODS

A systematic literature search was performed to identify studies on VTE in IBD. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Statements were developed through an iterative online platform, then finalized and voted on by a working group of adult and pediatric gastroenterologists and thrombosis specialists.

RESULTS

IBD patients have an approximately 3-fold higher risk of VTE compared with individuals without IBD, and disease flares further increase this risk. Anticoagulant thromboprophylaxis is recommended for IBD patients who are hospitalized with IBD flares without active bleeding and is suggested when bleeding is nonsevere. Anticoagulant thromboprophylaxis is suggested during moderate-severe IBD flares in outpatients with a history of VTE provoked by an IBD flare or an unprovoked VTE, but not otherwise. The recommended duration of anticoagulation after a first VTE is based on the presence of provoking factors. Specific suggestions are made for the prevention and treatment of VTE in pediatric and pregnant IBD patients.

CONCLUSIONS

Using the American College of Chest Physicians' guidelines as a foundation, we have integrated evidence from IBD studies to develop specific recommendations for the management of VTE in this high-risk population.

Prevalence of hypercoagulable disorders in inflammatory bowel disease

OBJECTIVE. Inflammatory bowel disease (IBD) can be associated with hypercoagulable disorders. Aim of this single-center, prospective study was an in-depth evaluation of acquired hypercoagulable states in IBD patients. METHODS. A total of 110 patients with Crohn's disease (CD) (aged 19-69; mean 40.5, median 38.5 years), 43 with ulcerative colitis (UC) (aged 17-72; mean 42, median 36 years), and 30 controls were enrolled. Full blood count, serum C-reactive protein (CRP), proteins C and S, activated protein C (APC) resistance, thrombin-antithrombin complex (TAT), F1+F2 fragments, tissue factor pathway inhibitor (TFPI) total and truncated, TFPI-factor Xa, tissue plasminogen activator (tPA) and PAI-I antigen were investigated in peripheral blood samples. RESULTS. Only 18 of 153 (11.8%) IBD patients had hemocoagulation parameters within normal range. Significant difference between IBD patients and controls was found in thrombocyte volume (p < 0.001), protein C (p = 0.025), protein S (p = 0.003), APC resistance (p < 0.001), F1+F2 fragments (p < 0.001), and tPA (p = 0.002). In CD patients who were divided into two subgroups according to serum CRP values (non-active disease: <5 mg/L; active disease ≥5 mg/L), thrombocyte count was significantly lower (p = 0.001), thrombocyte volume was significantly higher (p = 0.002), F1+F2 fragments were significantly lower (p = 0.007) and tPA was significantly higher (p = 0.038) in the subgroup with CRP <5 mg/L. In UC patients, no significant difference depending on CRP was found. CONCLUSIONS. Acquired hypercoagulable abnormalities in IBD patients are frequent. Patients with active CD, but not UC, displayed significantly different hemocoagulable parameters, when compared to non-active CD/UC subjects. In patients with active CD (with increased serum CRP concentration) and patients with active extensive UC found at endoscopy (despite low CRP values), prophylactic anticoagulation therapy should be considered.

Methylenetetrahydrofolate reductase C677T variant in Moroccan patients with inflammatory bowel disease

BACKGROUND

The association of genetic polymorphisms related to metabolism of homocysteine and folate with inflammatory bowel disease has been evidenced. Several studies have identified genetic variants of MTHFR as significant susceptibility loci for Crohn's disease (CD) and ulcerative colitis (UC). The C677T genetic polymorphism in the MTHFR gene is found to be associated with a thermolabile variant enzyme that shows a reduced activity. Therefore, we investigated whether the C677T variant confers genetic susceptibility to CD or UC and evaluated the genotype-phenotype associations in the Moroccan population.

METHODS

The present study included 96 inflammatory bowel disease patients (68 patients with CD and 28 with UC) and 182 healthy controls. DNA samples were genotyped for the MTHFR (C677T) mutation by the PCR-RFLP method. Statistical analyzes were performed using MedCalc software, Chi square test and Fisher test.

RESULTS

The respective odds ratio for CD, UC and control group were, 1.55 (CI 95%: 0.53-4.53, P=0.52); 0.50 (CI 95%: 0.06-4.15, P=0.52) and 0.50 (CI 95%: 0.06-4.15, P=0.52). Thus, no statistically significant association with the disease was observed in frequency of the TT variant in comparison to healthy controls. Stratification of IBD patients on the basis of CD or UC showed that individuals carrying at least one T allele are not protected against Crohn's disease. Furthermore, clinical features of the disease did not show any significant association.

CONCLUSION

In conclusion, the present study indicates that the genetic risk for IBD is not modulated by MTHFR C677T polymorphism in Moroccan population.

Meta-analysis: hyperhomocysteinaemia in inflammatory bowel diseases

BACKGROUND

The magnitude of association between homocysteine metabolism and inflammatory bowel diseases (IBD) remains unknown, whereas the association between hyperhomocysteinaemia and thrombosis remains controversial in IBD.

AIM

To conduct a systematic review and meta-analysis to examine these issues.

METHODS

The literature search was conducted using MEDLINE database and international conference abstracts from January 1966 to April 2011 and included all studies that evaluated plasma homocysteine level in IBD.

RESULTS

Twenty-eight studies evaluated the plasma homocysteine level and/or hyperhomocysteinaemia risk in IBD patients. Five studies assessed the association of hyperhomocysteinaemia with thrombosis. The mean plasma homocysteine level was significantly higher in IBD patients when compared with controls (weighted mean difference (WMD)=3.75 μmol/L; 95% CI, 2.23-5.26 μmol/L; P<0.0001; reference ranges for plasma homocysteine level: 5-12 μmol/L). The mean plasma homocysteine level did not differ between ulcerative colitis (UC) and Crohn's disease (CD) (WMD=0.41 μmol/L; 95% CI, -2.45 to 3.06 μmol/L; P=0.76). The risk of hyperhomocysteinaemia was significantly higher in IBD patients when compared with controls [odds ratio (OR)=4.65; 95% CI, 3.04-7.09; P<0.0001]. The risk of hyperhomocysteinaemia was not higher among IBD patients who experienced thromboembolic complications (OR=1.97; 95% CI, 0.83-4.67; P=0.12). Plasma folate level was inversely correlated with IBD risk associated with MTHFR C677T polymorphism (P=0.006).

CONCLUSIONS

The risk of hyperhomocysteinaemia is significantly higher in IBD patients when compared with controls. The risk assessment of hyperhomocysteinaemia-related thrombosis in IBD requires further investigation. Deficient folate status is associated with a higher impact of MTHFR C677T polymorphism on IBD risk.

Detection of thrombophilic mutations related to spontaneous abortions by a multiplex SNaPshot method

Spontaneous abortion is a significant clinical problem of different etiologies. Certain thrombophilia gene mutations have been associated with an increased risk of spontaneous abortion. Also, mutations in folate-related genes can lead to abnormal chromosomal segregation during meiosis which is the most common cause of spontaneous abortion. We have developed a multiplex single-base extension reaction assay that allows simultaneous analysis of 10 different mutations in thrombophilia- and folate-related genes (Factor V Leiden G1691A, Factor V H1299R, Factor II G20210A, Factor XIII V34L, PAI-I -675 4G/5G, FGB -455G/A, MTHFR C677T, MTHFR A1298C, MTR A2756G, and MTRR A66G). Using this method we have studied 232 women who had a spontaneous abortion and 209 of their male partners. Prevalence of Factor II G20210A and Factor V H1299R mutations was significantly higher in the women than in their male partners (2.4% and 0.7%, respectively [p=0.0499] for the Factor II mutation and 9.3% and 5.7%, respectively [p=0.0485] for the Factor V mutation). The prevalence of MTHFR C677T, MTHFR A1298C, MTR A2756G, and MTRR A66G mutations did not differ between the studied groups. In conclusion, we have developed a rapid, simple, reliable, and inexpensive multiplex SNaPshot method for determination of 10 thrombophilic mutations that may result in spontaneous abortions.

Genetic evidence supporting the association of protease and protease inhibitor genes with inflammatory bowel disease: a systematic review

As part of the European research consortium IBDase, we addressed the role of proteases and protease inhibitors (P/PIs) in inflammatory bowel disease (IBD), characterized by chronic mucosal inflammation of the gastrointestinal tract, which affects 2.2 million people in Europe and 1.4 million people in North America. We systematically reviewed all published genetic studies on populations of European ancestry (67 studies on Crohn's disease [CD] and 37 studies on ulcerative colitis [UC]) to identify critical genomic regions associated with IBD. We developed a computer algorithm to map the 807 P/PI genes with exact genomic locations listed in the MEROPS database of peptidases onto these critical regions and to rank P/PI genes according to the accumulated evidence for their association with CD and UC. 82 P/PI genes (75 coding for proteases and 7 coding for protease inhibitors) were retained for CD based on the accumulated evidence. The cylindromatosis/turban tumor syndrome gene (CYLD) on chromosome 16 ranked highest, followed by acylaminoacyl-peptidase (APEH), dystroglycan (DAG1), macrophage-stimulating protein (MST1) and ubiquitin-specific peptidase 4 (USP4), all located on chromosome 3. For UC, 18 P/PI genes were retained (14 proteases and 4 protease inhibitors), with a considerably lower amount of accumulated evidence. The ranking of P/PI genes as established in this systematic review is currently used to guide validation studies of candidate P/PI genes, and their functional characterization in interdisciplinary mechanistic studies in vitro and in vivo as part of IBDase. The approach used here overcomes some of the problems encountered when subjectively selecting genes for further evaluation and could be applied to any complex disease and gene family.

Haemostatic system in inflammatory bowel diseases: New players in gut inflammation

Inflammation and coagulation constantly influence each other and are constantly in balance. Emerging evidence supports this statement in acute inflammatory diseases, such as sepsis, but it also seems to be very important in chronic inflammatory settings, such as inflammatory bowel disease (IBD). Patients with Crohn’s disease and ulcerative colitis have an increased risk of thromboembolic events, and several abnormalities concerning coagulation components occur in the endothelial cells of intestinal vessels, where most severe inflammatory abnormalities occur. The aims of this review are to update and classify the type of coagulation system abnormalities in IBD, and analyze the strict and delicate balance between coagulation and inflammation at the mucosal level. Recent studies on possible therapeutic applications arising from investigations on coagulation abnormalities associated with IBD pathogenesis will also be briefly presented and critically reviewed.

Thrombosis and inflammatory bowel disease: a call for improved awareness and prevention

Thrombotic complications in patients with inflammatory bowel disease (IBD) are common and require improved awareness and prevention. In this review the interface between IBD and thrombosis is discussed, with emphasis on risk assessment and data to aid clinical decision making. Thromboembolic complications are 3-fold more likely in IBD patients than controls and the relative risk exceeds 15 during disease flares. Improved assessment of thrombosis risk for an individual patient includes thorough personal and family history and awareness of prothrombotic medications and lifestyle choices. Patients with the highest risk of thrombosis are those with active colonic disease, personal or strong family history of thrombosis, and those with significant acquired risk factors. Combined risk factors or hospitalization should prompt mechanical thromboprophylaxis. Indications for prophylactic anticoagulation are not defined currently by clinical studies, especially in pediatric patients, although some groups now advocate prophylactic anticoagulation for all hospitalized IBD patients and even some outpatients with disease flares. Thrombosis management requires a multidisciplinary therapeutic approach to balance anticoagulation and bleeding risk. While bleeding may occur with anticoagulation in IBD, data and experience indicate that therapeutic heparin is safe and bleeding manifestations can be managed supportively in most patients. Until prospective trials of prophylactic anticoagulation are published, management of thrombotic risk and prophylaxis in IBD will remain a clinical challenge.

Anterior ischemic optic neuropathy in a patient with Crohn's disease and aberrant MTHFR and GPIIIa gene variants

Large spectrums of ophthalmic manifestations from the anterior to the posterior segment have been so far reported in patients with inflammatory bowel disease. Anterior ischemic optic neuropathy is caused by acute ischemic infarction of the optic nerve head and is distinguished in two different types, non-arteritic anterior ischemic optic neuroparhy (NAION) which is the most frequent type and arteritic anterior ischemic optic neuropathy. Non-arteritic anterior ischemic optic neuroparhy may result in severe visual field loss. We present the case of a 69 year-old man with known history of Crohn's disease that was referred to the Department of Ophthalmology after noticing sudden blurred vision of his left eye. Ophthalmologic examination revealed a corrected visual acuity of 8/10 OS and 10/10 OD. Pupil examination showed a relative afferent pupillary defect of the left pupil and fluoroangiography revealed hyperfluorescence of the left optic disc, indicating edema and NAION attack on his left eye. Genetic analysis showed that the patient was homozygous for MTHFR C677T genetic polymorphism and A1/A2 heterozygous for GPIIIa polymorphism.

Genetic variants of homocysteine/folate metabolism pathway and risk of inflammatory bowel disease: a synopsis and meta-analysis of genetic association studies

A synopsis and meta-analysis of studies that investigated the association between genetic variants involved in the homocysteine/folate metabolism pathway and risk of inflammatory bowel disease (IBD) were conducted. Four variants (MTHFR C6TTT, MTHFR A1298C, MTR A2756G and MTRR A66G) showed significant associations in individual studies. In meta-analyses, only the variant MTR A2756G indicated an association with the risk of IBD for the allele contrast and the dominant model (odds ratio (OR) 1.48 (1.12-1.97) and OR 1.55 (1.12-2.15), respectively). The effect sizes for Crohn's disease and ulcerative colitis were similar to IBD. Cumulative meta-analysis for C677T indicated a downward trend of association as information accumulates.