Who are at risk for thromboembolism after arthroplasty? A systematic review and meta-analysis

Validation of the 5-SNP score for the prediction of venous thromboembolism in a Danish fast-track cohort of 6789 total hip and total knee arthroplasty patients

Background

Venous thromboembolism (VTE) is a serious complication following total hip arthroplasty (THA) and total knee arthroplasty (TKA). Despite improvements with fast-track treatment protocols, 0.5% of patients still develop a VTE within 90-days postoperatively. Previously, the 5-single nucleotide polymorphism (SNP) genetic risk scores (weighted and simplified) were developed to identify people at a high risk for VTE within the general population.

Objectives

We aimed to assess whether the 5-SNP scores could be used to identify high-risk patients in a cohort of fast-track THA/TKA patients.

Methods

A subset of patients from the Lundbeck Centre for Fast-track Hip and Knee Replacement Database was included based on the availability of genetic information. The 5-SNP scores were calculated for these patients, and their discriminatory performance was determined by c-statistic. Furthermore, the 5-SNP scores were added to a simple logistic prediction model containing clinical predictors to assess the added predictive value.

Results

A total of 7753 THA and TKA procedures (6798 patients) were included in this study. The c-statistics for the weighted and simple 5-SNP scores were 0.50 (95% CI, 0.39-0.61) and 0.48 (95% CI, 0.38-0.58), respectively. For the model with clinical predictors, the c-statistic was 0.67 (95% CI, 0.56-0.77). Addition of either of the 5-SNP scores did not improve discrimination in this model.

Conclusion

These findings do not support genetic risk profiling in fast-track THA/TKA patients to predict VTE. Hence, efforts should be directed at optimizing prediction models with clinical predictors.

Integrative analyses of genes about venous thromboembolism: An umbrella review of systematic reviews and meta-analyses

BACKGROUND

In recent years, many studies have found possible links between gene polymorphisms and venous thromboembolism (VTE). By identifying genetic risk factors before facing environmental risk factors such as surgical interventions and COVID-19 vaccination, we could rapidly respond to the risk of VTE. The aim of this study was to perform an umbrella review of genetic variants related to VTE. Integrative gene analysis of VTE was performed to identify critical genetic variations.

METHODS

This study conducted an umbrella review of systematic reviews and meta-analyses. All included studies were selected from the PubMed/MEDLINE database. To select eligible studies, the following variables were extracted: first author name; effect size of each study genetic variant; year of publication; the number of studies included in each article; ethnicity, sample size, P values, and heterogeneity estimates. To assess cumulative evidence in genetic epidemiology about effects of gene polymorphisms on VTE, Human Genome Epidemiology Network's Venice criteria were used. Methodological quality assessment was conducted with JBI Critical Appraisal Checklist for Systematic Reviews and Research Syntheses.

RESULTS

Genes provided in the present study with genetic variants associated with VTE were FVL (G1691A), Prothrombin (G20210A), MTHFR (C677T, A1298C), PAI-1 (4G/5G), factor VII activating protease (1601G > A), and endothelial protein C receptor (g.6936A_G, c.4600A_G). Among them, variants in FVL, Prothrombin, MTHFR, and PAI-1 showed high significance. Particularly, variants in Prothrombin (G20210A), MTHFR (C677T), and PAI-1 (4G/5G) had more than 2 types of model significance.

CONCLUSION

The present study performed a systematic review of genetic variants associated with VTE. Our results could lead to a more comprehensive understanding of VTE etiology. These results could give a strategy of prediagnosis about evaluating individual risks of VTE who might be exposed to environmental risk factors.

Machine learning-based prediction of the post-thrombotic syndrome: Model development and validation study

Background

Prevention is highly involved in reducing the incidence of post-thrombotic syndrome (PTS). We aimed to develop accurate models with machine learning (ML) algorithms to predict whether PTS would occur within 24 months.

Materials and methods

The clinical data used for model building were obtained from the Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis study and the external validation cohort was acquired from the Sun Yat-sen Memorial Hospital in China. The main outcome was defined as the occurrence of PTS events (Villalta score ≥5). Twenty-three clinical variables were included, and four ML algorithms were applied to build the models. For discrimination and calibration, F scores were used to evaluate the prediction ability of the models. The external validation cohort was divided into ten groups based on the risk estimate deciles to identify the hazard threshold.

Results

In total, 555 patients with deep vein thrombosis (DVT) were included to build models using ML algorithms, and the models were further validated in a Chinese cohort comprising 117 patients. When predicting PTS within 2 years after acute DVT, logistic regression based on gradient descent and L1 regularization got the highest area under the curve (AUC) of 0.83 (95% CI:0.76–0.89) in external validation. When considering model performance in both the derivation and external validation cohorts, the eXtreme gradient boosting and gradient boosting decision tree models had similar results and presented better stability and generalization. The external validation cohort was divided into low, intermediate, and high-risk groups with the prediction probability of 0.3 and 0.4 as critical points.

Conclusion

Machine learning models built for PTS had accurate prediction ability and stable generalization, which can further facilitate clinical decision-making, with potentially important implications for selecting patients who will benefit from endovascular surgery.

Venous Thromboembolism Prophylaxis in Elective Spine Surgery

STUDY DESIGN

Review.

OBJECTIVE

Venothromboembolic (VTE) complications, composed of deep vein thrombosis and pulmonary embolism are commonly observed in the perioperative setting. There are approximately 500 000 postoperative VTE cases annually in the United States and orthopedic procedures contribute significantly to this incidence. Data on the use of VTE prophylaxis in elective spinal surgery is sparse. This review aims to provide an updated consensus within the literature defining the risk factors, diagnosis, and the safety profile of routine use of pharmacological prophylaxis for VTE in elective spine surgery patients.

METHODS

A comprehensive review of the literature and compilation of findings relating to current identified risk factors for VTE, diagnostic methods, and prophylactic intervention and safety in elective spine surgery.

RESULTS

VTE prophylaxis use is still widely contested in elective spine surgery patients. The outlined benefits of mechanical prophylaxis compared with chemical prophylaxis varies among practitioners.

CONCLUSION

The benefits of any form of VTE prophylaxis continues to remain a controversial topic in the elective spine surgery setting. A specific set of guidelines for implementing prophylaxis is yet to be determined. As more risk factors for thromboembolic events are identified, the complexity surrounding intervention selection increases. The benefits of prophylaxis must also continue to be balanced against the increased risk of bleeding events and neurologic injury.

High risk of venous thromboembolism after orthopedic surgery in patients with thrombophilia

OBJECTIVE

This study aimed at evaluating the effect of thrombophilia on the risk of venous thromboembolism (VTE) in patients undergoing any type of orthopedic surgery.

BACKGROUND

Patients undergoing orthopedic surgery are at high risk for VTE. Although patients with thrombophilia have an increased risk of VTE, it is currently unclear whether there is a synergetic effect in patients with thrombophilia who undergo orthopedic surgery.

METHODS

Data from a large population-based case-control study (the Multiple Environmental and Genetic Assessment [MEGA] of risk factors for venous thrombosis study) were used. Odds ratios (ORs) with 95% confidence intervals (CIs), adjusted for age, sex, and body mass index (BMI) (ORadj) were calculated for patients undergoing any orthopedic intervention.

RESULTS

Of 4721 cases and 5638 controls, 263 cases and 94 controls underwent orthopedic surgery. Patients who had any orthopedic intervention in the year before the index date were at higher risk of VTE (ORadj 3.7; 95% CI, 2.9-4.8) than those who did not undergo any orthopedic surgery. There was an additionally increased risk in patients with factor V Leiden (OR 17.5, 95% CI, 4.1-73.6), non-O blood group (OR 11.2; 95% CI, 3.4-34.0), or elevated plasma levels of factor VIII (OR 18.6; 95% CI, 7.4-46.9) all relative to patients without these defects, not undergoing orthopedic surgery.

CONCLUSIONS

Patients with factor V Leiden, high levels of factor VIII, or blood group non-O were found to have a high risk of VTE after orthopedic surgery. Identification of these patients may enable individualized thromboprophylactic treatment to efficiently reduce VTE risk.

Prophylaxis of Venous Thromboembolism in Ankle and Foot Surgeries

Venous thromboembolism (VTE) is among the most feared complications by orthopedists both for due to its potentially lethal outcome and the uncertainties related to its prevention. Despite the vast literature on VTE prevention in major orthopedic surgeries, little is known about it in ankle and foot procedures. In orthopedics, adequate thromboprophylaxis requires a careful assessment of the thrombotic and hemorrhagic risks based on the procedure to be performed, as well as and knowledge on anticoagulant agents. The presentis review has the goal of assessing the risk of developingdiscusses VTE risk assessment, the modalities of thromboprophylaxis modalities, and the drugs used, with an emphasis on foot and ankle surgeries.

Factors predisposing to thrombosis after major joint arthroplasty

BACKGROUND

Total joint arthroplasty is one of the most common options for end stage osteoarthritis of major joints. However, we must take into account that thrombosis after hip/knee arthroplasty may be related to mutations in genes encoding for blood coagulation factors and immune reactions to anticoagulants [heparin-induced thrombocytopenia (HIT)/thrombosis]. Identifying and characterizing genetic risk should help to develop diagnostic strategies or modify anticoagulant options in the search for etiological mechanisms that cause thrombophilia following major orthopedic surgery.

AIM

To evaluate the impact of patients' coagulation profiles and to study specific pharmacologic factors in the development of post-arthroplasty thrombosis.

METHODS

In 212 (51 male and 161 female) patients that underwent primary total hip arthroplasty (100) or total knee arthroplasty (112) due to osteoarthritis during a period of 1 year, platelet counts and anti-platelet factor 4 (PF4)/heparin antibodies were evaluated pre/postoperatively, and antithrombin III, methylenetetrahydrofolate reductase, factor V and prothrombin gene mutations were evaluated preoperatively. In a minimum follow-up of 3 years, 196 patients receiving either low-molecular-weight heparins (173) or fondaparinux (23) were monitored for the development of thrombocytopenia, anti-PF4/heparin antibodies, HIT, and thrombosis.

RESULTS

Of 196 patients, 32 developed thrombocytopenia (nonsignificant correlation between anticoagulant type and thrombocytopenia, P = 0134.) and 18 developed anti-PF4/heparin antibodies (12/173 for low-molecular-weight heparins and 6/23 for fondaparinux; significant correlation between anticoagulant type and appearance of antibodies, P = 0.005). Odds of antibody emergence: 8.2% greater in patients receiving fondaparinux than low-molecular-weight heparins. Gene mutations in factor II or V (two heterozygotes for both factor V and II) were identified in 15 of 196 patients. Abnormal low protein C and/or S levels were found in 3 of 196 (1.5%) patients, while all patients had normal levels of von Willebrand factor, lupus anticoagulant, and antithrombin III. Four patients developed HIT (insignificant correlation between thrombocytopenia and antibodies) and five developed thrombosis (two had positive antibodies and two were heterozygotes for both factor II & V mutations). Thrombosis was not significantly correlated to platelet counts or HIT. The correlation of thrombosis to antibodies, factor II, factor V was P = 0.076, P = 0.043, P = 0.013, respectively.

CONCLUSION

Screening of coagulation profile, instead of platelet monitoring, is probably the safest way to minimize the risk of post-arthroplasty thrombosis. In addition, fondaparinux can lead to the formation of anti-PF4/heparin antibodies or HIT.

Genetic correlation between Prothrombin G20210A polymorphism and retinal vein occlusion risk

The aim of this study was to perform an updated meta-analysis to quantitatively investigate the association between G20210A polymorphism of Prothrombin gene and the risk of retinal vein occlusion (RVO), based on the available publications with inconsistent results. We utilized the Stata software to perform the heterogeneity test, association test, Begg's and Egger's tests, and sensitivity analysis. We searched three on-line databases (PubMed, Embase, and WOS) and obtained a total of 422 articles. Based on our selection criteria, 24 case-control studies were finally enrolled in this overall meta-analysis; a subgroup analysis by the factors ethnicity, control source, and RVO type was done. Through the association test of overall meta-analysis, we did not observe a significant difference between RVO cases and controls under the A vs G (allele) (z=1.49, P=0.137), A vs G (carrier) (z=1.42, P =0.155), GA vs GG (z=1.50, P=0.135), and GA+AA vs GG (z=1.50, P=0.135). Furthermore, we observed similar negative results in the association test of subgroup analysis (all P>0.05). Heterogeneity, Begg's, and Egger's tests excluded the presence of high heterogeneity and publication bias. Statistically stable results were observed in the sensitivity analyses. Based on integrated analysis of the current evidence, Prothrombin gene G20210A polymorphism is likely unrelated to the risk of RVO.

The timing of venous thromboembolic events after spine surgery: a single-center experience with 6869 consecutive patients

OBJECTIVE

Venous thromboembolic events (VTEs), including both deep venous thrombosis (DVT) and pulmonary embolism, are a major cause of morbidity and mortality after spine surgery. Prophylactic anticoagulation, or chemoprophylaxis, can prevent VTE. However, the timing of VTEs after spine surgery and the effect of chemoprophylaxis on VTE timing remain underinvestigated.

METHODS

The records of 6869 consecutive spine surgeries were retrospectively examined. Data on patient demographics, surgical variables, hospital course, and timing of VTEs were collected. Patients who received chemoprophylaxis were compared with those who did not. Appropriate regression models were used to examine selection for chemoprophylaxis and the timing of VTEs.

RESULTS

Age (OR 1.037, 95% CI 1.023–1.051; p < 0.001), longer surgery (OR 1.003, 95% CI 1.002–1.004; p < 0.001), history of DVT (OR 1.697, 95% CI 1.038–2.776; p = 0.035), and fusion surgery (OR 1.917, 95% CI 1.356–2.709; p < 0.001) predicted selection for chemoprophylaxis. Chemoprophylaxis patients experienced more VTEs (3.62% vs 2.03% of patients, respectively; p < 0.001), and also required longer hospital stays (5.0 days vs 1.0 days; HR 0.5107; p < 0.0001) and had a greater time to the occurrence of VTE (median 6.8 days vs 3.6 days; HR 0.6847; p = 0.0003). The cumulative incidence of VTEs correlated with the postoperative day in both groups (Spearman r = 0.9746, 95% CI 0.9457–0.9883, and p < 0.0001 for the chemoprophylaxis group; Spearman r = 0.9061, 95% CI 0.8065–0.9557, and p < 0.0001 for the nonchemoprophylaxis group), and the cumulative incidence of VTEs was higher in the nonchemoprophylaxis group throughout the 30-day postoperative period. Cumulative VTE incidence and postoperative day were linearly correlated in the first 2 postoperative weeks (R = 0.9396 and p < 0.0001 for the chemoprophylaxis group; R = 0.8190 and p = 0.0003 for the nonchemoprophylaxis group) and the remainder of the 30-day postoperative period (R = 0.9535 and p < 0.0001 for the chemoprophylaxis group; R = 0.6562 and p = 0.0058 for the nonchemoprophylaxis group), but the linear relationships differ between these 2 postoperative periods (p < 0.0001 for both groups).

CONCLUSIONS

Anticoagulation reduces the cumulative incidence of VTE after spine surgery. The cumulative incidence of VTEs rises linearly in the first 2 postoperative weeks and then plateaus. Surgeons should consider early initiation of chemoprophylaxis for patients undergoing spine surgery.

A study on dynamic monitoring, components, and risk factors of embolism during total knee arthroplasty

BACKGROUND

Fat embolism is a common complication of orthopedic surgery. However, the exact component and risk factor responsible for this complication remains unelucidated. This study aimed to detect the origin of the pulmonary embolus and identify relevant risk factors of pulmonary embolism in total knee replacement.

METHODS

A total of 40 osteoarthritis patients who underwent primary unilateral TKA were recruited into this study. Transesophageal echocardiography (TEE) was utilized to dynamically monitor the embolism. Pulmonary arterial pressure was recorded and biopsies were obtained from the medullary cavity during surgery.

RESULTS

After tourniquet release, the arterial embolism was observed by TEE to have a peak signal at 30 seconds when pulmonary arterial pressure was increased by 25% to 40% (P = .002). The pathology study of the embolism revealed its bone marrow origin. Total embolus quantity was positively correlated with age (P = .021), body mass index (BMI, P = .041), and fat content of the bone marrow (P = .003). Logistic regression analysis revealed that the fat content of the marrow (OR: 1.432, 95% CI: 1.335-1.592), age (OR: 1.632, 95% CI: 1.445-1.832), and BMI (OR: 1.231, 95% CI: 1.032-1.381) were risk factors for pulmonary hypertension.

CONCLUSION

This study revealed that the embolus detected in the right atrium was derived from bone marrow tissues, and this led to pulmonary arterial pressure fluctuations after tourniquet release. Therefore, elderly patients who have high BMI or bone marrow fat content are at high-risk for pulmonary fat embolism during TKA.

Effects of CYP3A5 polymorphisms on tacrolimus pharmacokinetics in pediatric kidney transplantation: a systematic review and meta-analysis of observational studies

BACKGROUND

CYP3A5 genetic polymorphisms have been reported to be strongly associated with the tacrolimus pharmacokinetics in adult kidney transplantation. However, there is no published meta-analysis in the influence of CYP3A5 variants on the requirements of the tacrolimus dose in pediatric renal-transplant recipients (RTRs). We wished to determine the effects of CYP3A5 polymorphisms on tacrolimus pharmacokinetics in pediatric RTRs.

METHODS

A literature search was conducted to include relevant articles by searching PubMed, EMBASE and the Cochrane Central Register of Controlled Trials. Pharmacokinetic-associated parameters such as dose administration, as well as concentrations and dose-adjusted concentrations of tacrolimus were extracted and the meta-analysis undertaken.

RESULTS

The meta-analysis involved four studies and one study series involving 268 pediatric RTRs. A significant difference was observed in the mean trough concentration/dose of tacrolimus between recipients carrying CYP3A5* 3/*3 variants (referred to as "non-expressers") and those carrying CYP3A5*1 (referred to as "expressers") [standard mean difference (SMD)=-1.09, 95% confidence interval (CI): -1.92 to -0.25, P=0.011]. Moreover, significance was observed in the mean daily dose of tacrolimus between non-expressers and expressers in pediatric RTRs (SMD=0.44, 95% CI: 0.20 to 0.68, P<0.001).

CONCLUSION

Our meta-analysis identified a positive correlation between CYP3A5 genotypes and tacrolimus pharmacokinetics in pediatric RTRs.

Prevalence of Venous Thromboembolic Events Is Low in Asians After Total Knee Arthroplasty Without Chemoprophylaxis

BACKGROUND

This retrospective cohort study was designed to establish the prevalence of clinically significant venous thromboembolic events (VTE) in our patients undergoing total knee arthroplasty (TKA) without chemoprophylaxis.

METHODS

A single-surgeon cohort of patients who underwent TKA from 2006 to 2014 were included. All patients had a pneumatic tourniquet applied and a drain inserted postoperatively. Tranexamic acid was not used perioperatively. All patients were under a standardized postoperative protocol with routine mechanical prophylaxis against VTE. None of the patients received prophylactic anticoagulation. All patients ambulated on the second postoperative day. Only symptomatic patients were referred for radiological examination to exclude VTE. We evaluated the patient demographics and calculated the prevalence of VTE in our cohort.

RESULTS

A total of 966 patients were reviewed. Mean age was 66.1 ± 7.8 years. Mean body mass index was 28.2 ± 4.7 kg/m². Mean tourniquet time was 53 ± 23 minutes. Patients stayed in hospital for a mean of 5.4 ± 3.1 days. There was 100% compliance to mechanical prophylaxis. And 11.1% of our patients were on concomitant antiplatelet or anticoagulant use. There were 8 patients with clinically significant VTE. This translates to a prevalence of 0.82%. Seven patients developed deep vein thrombosis and 1 patient died from massive pulmonary embolism.

CONCLUSION

The prevalence of clinically significant VTE in our patients who underwent TKA without routine chemoprophylaxis is 0.82%. With proper patient selection, risk stratification, and stringent perioperative protocols, routine chemoprophylaxis may not be necessary in Asians undergoing TKA.

Venous Thromboembolism After Knee Arthroscopy in Undiagnosed Familial Thrombophilia

Venous thromboembolism is uncommon after knee arthroscopy, and there are no guidelines for thromboprophylaxis in elective routine knee arthroscopy. Preoperative evaluation of common thrombophilias should provide guidance for postarthroscopy thromboprophylaxis in otherwise healthy patients who are at high risk for venous thromboembolism. This study assessed 10 patients with venous thromboembolism after total hip or knee arthroplasty. Patients were assessed if venous thromboembolism occurred within 6 months after knee arthroscopy (n=10) or total hip or knee arthroplasty (n=21). This study assessed gene mutations (factor V Leiden, prothrombin G20210A, plasminogen activator inhibitor, methylenetetrahydrofolate reductase) and serologic thrombophilias (high levels of factors VIII and XI, homocysteine, anticardiolipin immunoglobulin G and immunoglobulin M antibodies, and lupus anticoagulant; low antigenic protein C, S, and free S; and antithrombin III deficiency). The same coagulation data were obtained for normal subjects (n=110). The major thrombophilias in the arthroscopy group were factor V Leiden heterozygosity (40%), high factor VIII level (50%), and high homocysteine (30%). The respective values in control subjects were 2% (P=.0004), 7% (P=.0011), and 5% (P=.02). When the arthroscopy group was compared with the 21 patients who had venous thromboembolism after total hip or knee arthroplasty, the sole difference was factor V Leiden heterozygosity, which was 40% vs 0%, respectively (P=.007). Although venous thromboembolism after knee arthroscopy is uncommon, to identify high-risk patients and guide postoperative thromboprophylaxis, the authors suggest routine preoperative measurement of 3 common familial thrombophilias: factor V Leiden, factor VIII, and homocysteine. [Orthopedics. 2016; 39(6):e1052-e1057.].

Do Caucasians and East Asians have Different Outcomes Following Surgery for the Treatment of Degenerative Cervical Myelopathy?: Results From the Prospective Multicenter AOSpine International Study

STUDY DESIGN

A prospective multicenter cohort study.

OBJECTIVE

The aim of this study was to compare outcomes of surgery for the treatment for degenerative cervical myelopathy (DCM) between Caucasians and East Asians.

SUMMARY OF BACKGROUND DATA

Numerous studies have indicated that race can influence both disease prevalence and clinical prognosis in a variety of medical conditions; however, none have evaluated the impact of race on surgical outcomes in patients with DCM.

METHODS

Four hundred and seventy-nine patients with symptomatic DCM were enrolled in the prospective AOSpine CSM-International study at 16 global sites. Preoperatively, and at each follow-up, patients were evaluated using the modified Japanese Orthopedic Association scale (mJOA), the Nurick score, the Neck Disability Index (NDI), and the Short- Form 36 (SF-36) Health Survey. A mixed-model analytic approach was used to evaluate differences in outcomes between races at 24 months postoperatively, while controlling for relevant baseline characteristics and surgical factors.

RESULTS

Three hundred and twenty-four (67.64%) patients were Caucasian and 106 (22.13%) were East Asian. There was no difference in the incidence of ossification of the posterior longitudinal ligament (OPLL) between the two races; however a greater percentage of Caucasians in India (46.15%) and Turkey (41.38%) displayed evidence of OPLL than Caucasians in other regions (P < 0.001). The frequency of spondylosis was significantly higher in Caucasians (P < 0.001). Caucasians had a longer duration of symptoms (27.33 ± 34.47 months) than East Asians (23.11 ± 35.68 months) (P < 0.001), and a lower preoperative score on the SF-36 Physical Component Score (33.85 ± 9.04) than East Asians (37.47 ± 8.67) (P < 0.001). At 24 months after surgery, there were no differences in functional status or QOL between East Asians and Caucasians, after adjusting for baseline characteristics, surgical preferences, and disease causation. Rates of perioperative complications were not significantly different between the races (P = 0.261).

CONCLUSION

Decompressive surgery for DCM results in comparable functional gains and is equally safe in Caucasians and East Asians.

LEVEL OF EVIDENCE

2.

Hip Hemiarthroplasty in Two Patients with Severe Aortic Stenosis: Ethical Questions from an Anesthesiologist's Perspective

As the population ages, geriatric patients with preexisting cardiac disease are presenting for noncardiac surgery in escalating numbers. The decision to proceed with surgery in such patients often is multifactorial. With this in mind, we describe 2 patients with severe aortic stenosis who required hip operations: one urgent and one elective. Both patients had different anesthetic plans and did well intraoperatively. However, both patients died postoperatively because of their comorbidities. Although published guidelines are sparse, we hope this report will increase awareness and discussion about caring for geriatric patients with severe aortic stenosis.

Effect of follicle-stimulating hormone receptor Asn680Ser polymorphism on the outcomes of controlled ovarian hyperstimulation: an updated meta-analysis of 16 cohort studies

PURPOSE

The purpose of this study is to evaluate the influence of follicle-stimulating hormone receptor (FSHR) Asn680Ser polymorphism on the ovarian response to exogenous follicle-stimulating hormone (FSH) and clinical outcomes in women undergoing controlled ovarian hyperstimulation (COH).

METHODS

A database search was conducted to identify the eligible studies that investigated the effect of FSHR Asn680Ser polymorphism on ovarian response and clinical outcomes. A pooled analysis was performed with the odds ratio (OR) or weighted mean difference (WMD) and their respective 95 % confidence interval (CI) by the STATA software with random effects model.

RESULTS

Sixteen cohort studies comprising a total of 4287 subjects were included. The number of retrieved oocytes was significantly fewer in subjects with the SS genotype at position 680, compared to subjects with the NN or NS genotype (WMD = -1.36, 95 % CI = -1.85 to -0.87). Lack of association was detected between the genotypes (SS genotype vs. NN or NS genotype) and clinical outcomes such as exogenous FSH dose (WMD = 98.96 IU, 95 % CI = -22.33 to 220.24), poor response (OR = 1.08, 95 % CI = 0.71-1.64), ovarian hyperstimulation syndrome (OHSS) (OR = 1.58, 95 % CI = 0.41-6.07), and clinical pregnancy rate (OR = 1.10, 95 % CI = 0.86-1.40). However, poor ovarian response and number of retrieved oocytes were significantly influenced by the Asn680Ser polymorphism in the Asian subjects. In addition, no publication bias was detected.

CONCLUSION

FSHR Asn680Ser polymorphism might be a significant biomarker for predicting the number of retrieved oocytes and poor response, especially in Asian subjects. Other outcomes such as exogenous FSH dose, OHSS, and pregnancy rate were not influenced by FSHR Asn680Ser polymorphism.

Effects of the CYP3A4*1B Genetic Polymorphism on the Pharmacokinetics of Tacrolimus in Adult Renal Transplant Recipients: A Meta-Analysis

BACKGROUND AND OBJECTIVE

The association between the CYP3A4*1B single nucleotide polymorphism (SNP) and tacrolimus pharmacokinetics in different studies is controversial. Therefore, a meta-analysis was employed to evaluate the correlation between the CYP3A4*1B genetic polymorphism and tacrolimus pharmacokinetics at different post-transplantation times in adult renal transplant recipients.

METHODS

Studies evaluating the CYP3A4*1B genetic polymorphism and tacrolimus pharmacokinetics were retrieved through a systematical search of Embase, PubMed, the Cochrane Library, ClinicalTrials.gov and three Chinese literature databases (up to Sept. 2014). The pharmacokinetic parameters (weight-adjusted tacrolimus daily dose and tacrolimus trough concentration/weight-adjusted tacrolimus daily dose ratio) were extracted, and the meta-analysis was performed using Stata 12.1.

RESULTS

Seven studies (involving 1182 adult renal transplant recipients) were included in this meta-analysis. For the weight-adjusted tacrolimus daily dose, in all included renal transplant recipients (European & Indian populations), CYP3A4*1/*1 recipients required a significantly lower weight-adjusted tacrolimus daily dose than did CYP3A4*1B carriers at 7 days (WMD -0.048; 95% CI -0.083 ~ -0.014), 6 months (WMD -0.058; 95% CI -0.081 ~ -0.036) and 12 months (WMD - 0.061; 95% CI -0.096 ~ -0.027) post-transplantation. In light of the heterogeneity, the analysis was repeated after removing the only study in an Indian population, and CYP3A4*1/*1 European recipients (mostly Caucasian) required a lower weight-adjusted tacrolimus daily dose within the first year post-transplantation. The tacrolimus trough concentration/weight-adjusted tacrolimus daily dose ratio (C0/Dose ratio) was significantly higher in CYP3A4*1/*1 recipients than in CYP3A4*1B carriers at 6 months (WMD 52.588; 95% CI 22.387 ~ 82.789) and 12 months (WMD 62.219; 95% CI 14.218 ~ 110.221) post-transplantation. When the only study in an Indian population was removed to examine European recipients (mostly Caucasian), the significant difference persisted at 1 month, 6 months and 12 months post-transplantation.

CONCLUSION

Based on our meta-analysis, the CYP3A4*1B genetic polymorphism affects tacrolimus dose requirements and tacrolimus trough concentration/weight-adjusted tacrolimus daily dose ratio within the first year post-transplantation in adult renal transplant recipients, especially in European recipients (mostly Caucasian).

Is the microRNA-146a (rs2910164) polymorphism associated with rheumatoid arthritis? Association of microRNA-146a (rs2910164) polymorphism and rheumatoid arthritis could depend on gender

BACKGROUND

To investigate a possible effect of a gene mutation on rheumatoid arthritis (RA), we performed genotyping, in a hospital-based, case-control study in a Chinese cohort, relating the single nucleotide polymorphism (SNP) of microRNA (miRNA)-146a (rs2910164) to RA and undertook a meta-analysis using the available literature.

METHODS

Six hundred and fifteen RA patients and 839 controls were enrolled in our study. A polymorphism of the miRNA-146a (rs2910164) gene was detected using a custom-by-design 48-Plex SNPscan TM Kit. In addition, we performed a systematic literature research and identified an additional 7 studies with 1066 cases and 1513 controls.

RESULTS

We did not find a significant association of miRNA-146a polymorphism with an RA risk in our data. And the results of the meta-analyses suggested no significant association between miRNA-146a polymorphism and RA in any genetic model. However, when the subgroup analyses were performed, genotype GG was observed to be significantly associated with RA in females. And the DAS28 score may also be significantly influenced by CC genotype.

CONCLUSIONS

Our study suggested that miRNA-146a polymorphism might not be associated with RA susceptibility. However, the miRNA-146 GG genotype might increase the risk of RA in females, and CC genotype may influence disease activity when evaluated with DAS28 score.

Diagnostic ramifications of ocular vascular occlusion as a first thrombotic event associated with factor V Leiden and prothrombin gene heterozygosity

AIM

This study aimed to assess the diagnostic ramifications of vascular occlusion of the ocular vein and artery as a first thrombotic event associated with factor V Leiden (FVL) and/or prothrombin gene (PTG) heterozygosity.

METHODS

Patients with ocular vein (n=191) and artery (n=74) occlusion, free of cardioembolic etiologies, were sequentially referred from vitreoretinal specialists for measurement of thrombophilia-hypofibrinolysis and compared to 110 healthy normal controls.

RESULTS

Of the 265 patients, 29 (11%; 17 women, 12 men) of all referred ocular vascular occlusion (OVO) cases were found to be heterozygous for FVL and/or PTG, including 16 with FVL, 12 with PTG, and 1 with both. Of the 29 cases, 16 had central retinal vein occlusion (CRVO), 2 branch retinal vein occlusion (BRVO), 5 nonarteritic anterior ischemic optic neuropathy (NA-AION), 3 retinal artery occlusion (RAO), 2 amaurosis fugax (AF), and 1 had both CRVO and RAO. Of the 16 FVL cases, 15 (94%) had OVO as a first thrombotic event without prior deep venous thrombosis (DVT) or pulmonary embolism (PE); 6 (38%) also had other thrombotic events, including recurrent miscarriage, osteonecrosis, ischemic stroke, and/or ischemic colitis; and 5 (31%) had immediate family members with previous venous thromboembolism (VTE). Of the 12 PTG cases, 9 (75%) had OVO as a first thrombotic event, 5 (42%) experienced VTE other than DVT or PE, and 6 (50%) had immediate family members with VTE. In one patient with both FVL and PTG, DVT occurred before BRVO. Of the 17 women with FVL and/or PTG mutations, 7 (41%) experienced ≥1 miscarriage, 6 (35%) were on estrogen therapy, and 1 (6%) was on clomiphene.

CONCLUSION

Of the 265 patients with OVO, 29 (11%) had FVL and/or PTG, and 83% of these 29 cases presented with OVO as their first thrombotic event. By diagnosing thrombophilia as an etiology for OVO, the ophthalmologist opens a window to family screening and preventive therapy.

Genetic susceptibility to prosthetic joint infection following total joint arthroplasty: A systematic review

BACKGROUND

Prosthetic joint infection (PJI) is the most common cause of total joint arthroplasty failure and revision surgery. Genetic polymorphisms could be determinant factors for PJI.

METHODS

We performed a systematic research of Medline, Pubmed, Embase, Cochrane Library, and Google Scholar, and identified 11 studies with 34 kinds of gene polymorphisms, were included in the synthesis.

RESULTS

Our data suggest that the C allele and genotype C/C for MBL-550 SNP, genotype A/A for MBL-54 SNP and G allele for MBL-221 SNP increase the risk of PJI, while G allele and genotype G/G for MBL-550 SNP decrease the risk of PJI in Caucasian populations. Several other genes reported by single-center studies also contribute to the genetic susceptibility to septic PJI. No definitive conclusions could be achieved due to the small amount of data in the included studies.

CONCLUSION

Several genes contribute to the genetic susceptibility to PJI following total joint arthroplasty. Further studies will enhance the understanding of PJI, and may inform and direct early interventions.

Prevalence and risk factors for development of venous thromboembolism after degenerative spinal surgery

STUDY DESIGN

Prospective clinical study.

OBJECTIVE

To identify the incidence and risk factors for venous thromboembolism (VTE) associated with degenerative spinal surgery procedures at the different spinal levels for various pathologies.

SUMMARY OF BACKGROUND DATA

Spinal surgery includes procedures for treatment of various pathologies at different spinal levels. There have been no studies on VTE after degenerative spinal surgery with respect to screening patients for both deep venous thrombosis and pulmonary thromboembolism (PE).

METHODS

We prospectively investigated the occurrence of VTE after degenerative spinal surgery in 459 patients who were divided into 5 groups: group 1, patients with cervical degenerative disease treated with posterior decompression; group 2, patients with cervical degenerative disease treated with instrumentation for spinal fusion; group 3, patients with thoracolumbar degenerative disease treated with instrumentation for spinal fusion; group 4, patients with lumbar spinal stenosis treated with posterior decompression; and group 5, patients with lumbar spondylolisthesis treated with 1-level posterior lumbar interbody fusion. A deep venous thrombosis and PE screening was performed for all patients. Binomial logistic regression analysis was used to assess the association of risk factors.

RESULTS

The incidence of VTE was 2.8%, 3.4%, 10.8%, 12.5%, and 10.1% in groups 1, 2, 3, 4, and 5, respectively. Female sex, advanced age, spinal level, and neurological deficits, were all risk factors. Cervical spinal surgery in particular had an associated low risk. In patients with PE, 3 of the 4 had no deep venous thrombosis, indicating that screening for PE is also needed in high-risk patients.

CONCLUSION

The prevalence of VTE after elective spinal surgery was different in each group.

LEVEL OF EVIDENCE

3.

Association between the plasminogen activator inhibitor-1 4G/5G polymorphism and risk of venous thromboembolism: a meta-analysis

INTRODUCTION

The plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism was considered to be associated with risk of venous thromboembolism (VTE), while evidence remains inadequate. To provide a more accurate estimation of this relationship, we performed an updated meta-analysis of all eligible studies.

MATERIALS AND METHODS

A systematical search was performed in PubMed, EMBASE, Wanfang, China National Knowledge Infrastructure (CNKI) and Cqvip databases to identify relevant studies published before March 6(th) 2014. The odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using the fixed/random-effects model using Review Manager 5.1 and STATA 12.0.

RESULTS

A total of 34 studies with 3561 cases and 5693 controls were analyzed. Overall, significant association between the PAI-1 4G/5G variant and VTE risk in total population (dominant model: OR=1.32, 95%CI: 1.13-1.54) was observed. And this variant was also related to the deep vein thrombosis risk (dominant model: OR=1.60, 95%CI: 1.24-2.06, P=0.0003). In the subgroup analyses on ethnicity, significant results were obtained in both Asians (dominant model: OR=2.08, 95%CI: 1.29-3.35, P=0.003) and Caucasians (dominant model: OR=1.31, 95%CI: 1.10-1.56, P=0.003). However, no significant association was found in patients with provoked VTE. In terms of subgroup analyses on co-existence of other thrombotic risk factors, the PAI-1 4G/5G polymorphism was significantly associated with VTE risk in patients with factor V Leiden mutation (dominant model: OR=1.72, 95%CI: 1.17-2.53), but not in patients with cancer or surgery.

CONCLUSION

Our findings demonstrate the role of PAI-1 4G/5G polymorphism being a risk candidate locus for VTE susceptibility, especially in patients with other genetic thrombophilic disorders.