Interaction of thrombophilic SNPs in patients with unexplained infertility-multifactor dimensionality reduction (MDR) model analysis.

PURPOSE: Our aim was to evaluate the frequency and SNP-SNP interactions between factor V Leiden (FVL) G1691A, prothrombin G20210A mutation, and C677T MTHFR and PAI-1 4G/5G gene polymorphisms in female IVF patients with unexplained infertility (UI) by using a multifactor dimensionality reduction (MDR) model analysis. METHODS: A total of 225 subjects were enrolled in the study. There were 105 females in UI group and 120 healthy controls. Designated SNPs were determined by using allele-specific PCR methods. The difference in thrombophilia prevalence was assessed by a chi-square test and logistic regression analysis. Four-locus SNP interaction model was tested using the MDR approach. A ten-fold cross-validation consistency (CVC) and permutation testing were performed. RESULTS: There was a significant difference of MTHFR C677T polymorphism frequency between the groups. Significantly less UI patients had MTHFR CC genotype (p = 0.005), while the risk allele T was more frequent (OR = 1.83, p = 0.0018). Logistic regression determined a significant association only for MTHFR C677T in our patients (TT genotype OR = 2.99). The MDR analysis confirmed the significance of a single-locus model for MTHFR C677T polymorphism (p = 0.015; OR = 2.93). However, the best, significant predictive model was the two-locus model comprising MTHFR C677T and FVL (CVC = 10/10, testing accuracy = 60.95%, p = 0.013; OR = 3.02). CONCLUSION: The MTHFR C677T polymorphism was significantly associated with UI, with minor allele T being more frequent. Additionally, there was a significantly increased presence of MTHFR C677T with FVL mutation in these patients. Therefore, MTHFR and its interaction with FVL should be recognized as contributing factors in the pathogenesis of infertility.

Comparison of Phenotypic Activated Protein C Resistance Testing With a Genetic Assay for Factor V Leiden.

Objectives: To compare the accuracy and reliability of phenotypic activated protein C resistance (aPC-R) assays with a genotypic assay for the factor V Leiden F5 p.R506Q (FVL) mutation. Methods: Data were obtained from an electronic data warehouse for FVL testing performed at an academic institution with a large referral laboratory service. In total, 1,596 patients were identified who had undergone both phenotypic aPC-R and genotypic FVL mutation testing. Results: Phenotypic testing showed a high level of sensitivity, specificity, and other biostatistical values compared with genotypic testing. Improvements in technology decreased the amount of equivocal phenotypic results. Conclusions: Phenotypic assays had close to total concordance with genotypic assays over 16 years of testing. Changing ordering practices could result in up to an 80% reduction in testing costs.

Activated Protein C Resistance Does Not Increase Risk for Recurrent Stroke or Death in Stroke Patients.

BACKGROUND: Activated protein C (APC) resistance is the most common inherited prothrombotic disorder. The role of APC resistance in ischemic stroke is controversially discussed. OBJECTIVES: The aim of this single center follow up study was to investigate the effect of APC resistance on stroke recurrence and survival in stroke patients. PATIENTS/METHODS: We retrospectively identified 966 patients who had had an ischemic stroke or transitory ischemic attack (TIA) and in whom laboratory tests for APC resistance had been conducted. These patients were contacted to determine the primary outcomes of recurrent ischemic stroke or death. RESULTS: A total of 858 patients with an average follow up time of 8.48 years were included. APC resistance did not influence cumulative incidence functions for stroke free and total survival. In multivariate analyses, crude and adjusted hazard ratios for recurrent stroke as well as for death where not significantly increased in patients with APC resistance. This also applies to the subgroups of young patients, patients with cryptogenic stroke and patients with atrial fibrillation. CONCLUSION: APC-resistance is not a risk factor for subsequent stroke or death in patients with a first ischemic stroke or TIA. Testing for APC-resistance in stroke patients therefore cannot be routinely recommended.

Low molecular weight heparin modulates maternal immune response in pregnant women and mice with thrombophilia.

PROBLEM: Thrombophilia is associated with pregnancy complications. Treatment with low molecular weight heparin (LMWH) improves pregnancy outcome, but the underlying mechanisms are not clear. METHODS OF STUDY: We analyzed Treg frequency in blood from thrombophilic pregnancies treated with LMWH (n = 32) or untreated (n = 33) and from healthy pregnancies (n = 39) at all trimesters. Additionally, we treated pregnant wild-type, heterozygous and homozygous factor-V-Leiden (FVL) mice with LMWH or PBS and determined Treg frequency, pro-/anti-inflammatory cytokine levels and Caspase-3-activity in placenta and decidua. RESULTS: Treg frequencies were increased in second and third trimester in LMWH-treated thrombophilic pregnancies compared to controls. Treg levels were comparable to those of normal pregnancies. Homozygous FVL mice had decreased decidual Tregs compared to wild-type mice. LMWH treatment normalized Tregs and was associated with increased decidual IL-10 mRNA. LMWH diminished Caspase-3-activity in mice of all genotypes. CONCLUSION: We demonstrated anti-apoptotic and anti-inflammatory effects of LMWH in pregnant FVL mice. LMWH increased Treg levels in mice and humans, which suggests benefits of LMWH treatment for thrombophilic women during pregnancy.

Late failure of a split-thickness skin graft in the setting of homozygous factor V Leiden mutation: a case report and correlative animal model from the Wound Etiology and Healing (WE-HEAL) study.

We present the case of a 53-year-old Caucasian male smoker with remote history of left lower extremity deep venous thrombosis (DVT) and a strong family history of thrombosis, who presented to the Center for Wound Healing at MedStar Georgetown University Hospital with spontaneous left leg ulceration. Prothrombotic evaluation showed homozygosity for the factor V Leiden (FVL) mutation. Therapeutic anticoagulation was commenced with warfarin (Coumadin®) and the patient underwent successful debridement and Apligraf® followed by split-thickness skin graft (STSG) of two wounds. He had an uneventful postoperative course and on the 27th postoperative day the grafts were 95% intact. However, by postoperative day 41 there was 10% graft loss, and over the subsequent 2 weeks both grafts necrosed. On further questioning, it transpired that the patient had discontinued his warfarin on postoperative day 37 because he thought that it was no longer necessary. The patient is enrolled in the Wound Etiology and Healing (WE-HEAL) study, and at the time of the original graft, residual skin fragments from the STSG were transplanted onto a nude mouse for development of an animal model of wound healing. The mouse graft was successful and was harvested at postoperative day 87 for pathological examination. We review the mechanisms by which prothrombotic states, particularly FVL mutation, can contribute to skin graft failure and delayed wound healing. This case highlights the importance of considering prothrombotic conditions in patients with spontaneous leg ulcerations and the impact of therapeutic anticoagulation on healing. It further allows us to demonstrate the efficacy of the animal model in which residual fragments of STSG tissue are utilised for transplant onto nude mice for manipulation in the laboratory.

Vascular graft thrombosis secondary to activated protein C resistance: a case report and literature review.

Hypercoagulability is a well-documented and prominent risk factor for venous thromboembolism. The role of thrombophilia in arterial thrombotic events is less well defined. A 52-year-old male patient with multiple atherogenic risk factors was admitted for non-healing pedal ulcer and absent distal pulses. Based on the clinical presentation, Doppler ultrasound and angiography findings, the patient underwent elective in situ bypass arterial reconstruction. The saphenous vein graft was of satisfactory quality and the procedure went routinely. Acute graft thrombosis on postoperative day 0 was recognized immediately and prompted an emergent surgical revision. No technical errors or anatomical/mechanical causes for failed reconstruction were found and the graft was successfully thrombectomized using a Fogarty balloon-catheter. Graft rethrombosis, however, ensued after several hours. Considering the absence of threatening limb ischemia and the idiopathic recurrent thrombosis, raising suspicion of prothrombotic state, conservative treatment was pursued. Postoperative thrombophilia testing proved positive for activated protein C resistance, mandating introduction of chronic oral anticoagulation. Six months later, the operated extremity is viable. Inexplicable vascular graft thrombosis, particularly if early and recurrent, should raise suspicion of underlying thrombophilia. If confirmed by laboratory testing, long-term secondary antithrombotic prophylaxis may be required.

[Adrenal vein thrombosis during pregnancy]. / Thrombose veineuse surrénalienne en cours de grossesse.

Pregnancy represents an inner transitional prothrombotic state; that is why other coagulation abnormalities may be revealed during this time. Factor V Leiden mutation is the most frequent inherited thrombophilia in the general population. We report the case of a patient by whom this mutation has been revealed during pregnancy by an adrenal vein thrombosis. Through this case, we will review the physiopathology of resistance to activated protein C and its consequences.

Activated protein C and acute kidney injury: Selective targeting of PAR-1.

Protein C is a plasma serine protease that when activated plays a central role in modulating the function of the vascular endothelium and its interface with the innate immune system. Activated protein C (APC) has a dual mechanism of action via the feedback inhibition of thrombin generation, and as an agonist of protease activated receptor-1 (PAR-1). Through different cofactor interactions, this dual mechanism of antithrombotic and cytoprotective activity results in the ability of APC to modulate endothelial dysfunction by blocking cytokine signaling, functional cell adhesion expression, vascular permeability, apoptosis, and modulating leukocyte migration and adhesion. Deficiency in protein C, which occurs during systemic inflammatory activation, is highly associated with organ dysfunction. APC has shown efficacy in a number of preclinical models of thrombosis and ischemia, and the recombinant human APC drotrecogin alfa (activated), reduces mortality in patients with high-risk severe sepsis. The ability of APC to suppress pro-inflammatory pathways and enhance cellular survival suggests that APC plays a key role in the adaptive response to protect the vessel wall from insult and to enhance endothelial, cellular, and organ survival. The focus of this review will be to summarize the emerging data suggesting the potential therapeutic benefit of APC and related members of the pathway in the prevention and treatment of acute kidney injury.