The Prothrombin-Prothrombinase Interaction.

The hemostatic response to vascular injury entails a sequence of proteolytic events where several inactive zymogens of the trypsin family are converted to active proteases. The cascade starts with exposure of tissue factor from the damaged endothelium and culminates with conversion of prothrombin to thrombin in a reaction catalyzed by the prothrombinase complex composed of the enzyme factor Xa, cofactor Va, Ca2+, and phospholipids. This cofactor-dependent activation is paradigmatic of analogous reactions of the blood coagulation and complement cascades, which makes elucidation of its molecular mechanism of broad significance to the large class of trypsin-like zymogens to which prothrombin belongs. Because of its relevance as the most important reaction in the physiological response to vascular injury, as well as the main trigger of pathological thrombotic complications, the mechanism of prothrombin activation has been studied extensively. However, a molecular interpretation of this mechanism has become available only recently from important developments in structural biology. Here we review current knowledge on the prothrombin-prothrombinase interaction and outline future directions for the study of this key reaction of the coagulation cascade.

Prothrombin G20210A Mutation is Rare but not Absent Among North Indian Patients with Thromboembolic Events.

Traditionally considered to be absent in India, prothrombin gene G20210A (NM_000506.5(F2): c.*97G > A) mutation (PGM) has recently been reported in few Indian patients. We aimed to assess the prevalence of PGM in patients with thromboembolic events from north India region. The thrombophilia workup comprising Protein C, Protein S, Antithrombin functional activity, lupus anticoagulant and anti-ACA and anti-ß2GP1 antibodies were performed in coagulation analyzer (ACLTOP-500, Instrumentation Laboratory, USA) and automated chemiluminescent assay analyzer (ACUSTAR, IL) respectively. PCR-RFLP was used to perform PGM and FVL mutation. Out of 509 patients, DVT and CVT/CSVT were identified in 208 and 250 patients respectively. A total of 42 (8.2%) cases showed inherited thrombophilia and 11 (2.1%) acquired thrombophilia. Among the inherited defects, the most common was FVL mutation 31 (6%) The PGM was seen in only 2/509 (0.3%) patients. The prevalence of PGM in North Indian patients with DVT, stroke and CVT is 0.41% (2/509). Although PGM is rare in this population, its presence emphasizes its association with these conditions. However, the role of PGM testing remains debatable due to its scarcity among North Indians. Supplementary Information: The online version contains supplementary material available at 10.1007/s12288-024-01741-x.

A novel factor V compound heterozygous mutation associated with thrombosis (Y1961C; FV-Kanazawa, together with 1982_1983del).

BACKGROUND: ; Factor (F)V is pivotal in both procoagulant and anticoagulant mechanisms. The present report describes a novel F5 mutation in a FV-deficient patient (FV:C 6 IU/dL, FV:Ag 32 IU/dL), complicated with recurrent deep vein thrombosis. The patient demonstrated activated protein C resistance (APCR) with compound heterozygous mutations consisting of FV-Y1961C (FVKanazawa) and FV-1982_1983del. AIM;: To clarify thrombotic mechanisms associated with this FV abnormality. METHODS AND RESULTS: Levels of FV-1982_1983del were below the detection sensitivity in our expression experiments using HEK293T cells, and analyses were targeted, therefore on the FV-Y1961C mutation. APTT-based clotting assays demonstrated that FV-Y1961C exhibited APCR, and that the reduced APC susceptibility in FVa-Y1961C resulted in a marked depression of APC-catalyzed inactivation with delayed cleavage at Arg506 and little cleavage at Arg306 with or without protein (P)S. The APC cofactor activity of FV-Y1961C in APC-catalyzed FVIIIa inactivation promoted by Arg336 cleavage in FVIII was impaired. The binding affinity of FVa-Y1961C to phospholipid membranes was reduced in reactions involving APC/PS-catalyzed inactivation and in prothrombinase activity. Furthermore, the addition of FVa-Y1961C to plasma failed to inhibit tissue factor (TF)-induced procoagulant function. These characteristics were similar to those of FV-W1920R (FVNara) and FV-A2086D (FVBesançon). CONCLUSIONS: ; We identified a compound heterozygous. FV-Y1961C mutation in the C1 domain representing a novel FV mutation (FVKanazawa) resulting in not only APCR due to impaired FVa susceptibility and FV cofactor activity for APC function, but impaired inhibition of TF-induced procoagulant function. These defects in anticoagulant function associated with FV in FV-Y1961C contributed to a prothrombotic state.

Massive Pulmonary Embolism Associated With Factor V Leiden Mutation in a Young Female on Oral Contraceptive Pills: A Case Report.

Factor V Leiden (FVL) is the major genetic risk factor to predispose venous thromboembolism (VTE). We present a rare case of a 34-year-old Caucasian female heterozygous for this mutation and taking oral contraceptive pills (OCPs) for less than four months, who presented to the emergency department with acute onset of dyspnea and was diagnosed to have an isolated massive bilateral pulmonary embolism (PE). The patient was managed for six days in the hospital and was discharged on oral anticoagulants. The risk for VTE in patients with factor V Leiden and on oral contraceptive pills increases by 30-fold in heterozygous women and 100-fold in homozygous women. The risk of VTE in factor V Leiden seems to outweigh the benefit of contraception with oral contraceptive pills. This case suggests that thrombophilia screening should be considered only in patients with a positive first-degree family history of VTE, where necessary, to prevent any future thrombotic morbidity and mortality.

A Rare Presentation of Ascites Secondary to Inferior Vena Cava Thrombosis in a Patient With Factor V Leiden Mutation.

We present the case of a 36-year-old female with Factor V Leiden mutation taking warfarin, who presented to the emergency department with swelling in the abdominal and bilateral lower extremities. Initial assessment revealed an international normalized ratio (INR) of 5.0. Abdomen/pelvis computed tomography (CT) and computed tomographic angiography (CTA) scans indicated chronic thrombosis of the inferior vena cava (IVC), leading to the development of ascites and swelling. Extensive investigations were conducted to explore potential contributing factors for the ascites and edema, all of which yielded negative results. Warfarin was discontinued, and unfractionated heparin was initiated once the INR decreased to 2.0. The patient underwent IVC angioplasty with stent placement, resulting in significant improvement of ascites and lower extremity swelling. Subsequently, heparin was transitioned to oral warfarin, and therapeutic INR levels were achieved before discharge. At the follow-up outpatient visit, the patient's ascites and lower extremity edema had completely resolved. This case highlights a rare instance of IVC involvement associated with Factor V Leiden mutation. Furthermore, the patient's history of noncompliance with medication, initial supratherapeutic INR, and chronic IVC thrombosis emphasize the importance of medication adherence and the crucial role of primary care in ensuring regular follow-up and monitoring.

EGFR-TKI-induced Factor V deficiency in a patient with advanced non-small cell lung cancer: The first case report.

Osimertinib, a third-generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI), is routinely prescribed as first-line therapy for advanced non-small cell lung cancer, regardless of the presence of the T790M resistance mutation. This study reports a rare case of Factor V inhibitor detection during osimertinib therapy in a patient with lung adenocarcinoma. These findings underscore the importance of vigilant monitoring for coagulation abnormalities during EGFR-TKI therapy.

Total Hip Arthroplasty in Patients Who Have Factor V Leiden: Elevated Risks Isolated to Venous Thromboembolism Events.

BACKGROUND: Total hip arthroplasty (THA) is a common procedure that requires consideration of preexisting comorbidities. Factor V Leiden (FVL), an inherited thrombophilia, is one such condition that predisposes patients to venous thromboembolism (VTE, deep vein thrombosis, and pulmonary embolism). The present study aimed to characterize the risks associated with FVL patients undergoing THA and evaluate the effect of VTE chemoprophylactic agents on these risks. METHODS: A total of 544,022 adult patients who underwent primary THA for osteoarthritis indications between 2010 and October 2021 were identified in an administrative claims database. Of these, FVL was identified in 1,138 (0.21%). Patients who had and did not have FVL were matched at a 1:4 ratio (1,131 with FVL and 4,519 without FVL) based on age, sex, and Elixhauser comorbidity index. Univariable and multivariable analyses were assessed for 90-day complications. Implant survival at 5 years was assessed and compared with log-rank tests. The relative use of different chemoprophylactic agents, including aspirin, warfarin, heparin, or direct oral anticoagulant (DOAC), was assessed. Bleeding events and VTE were compared for those prescribed either aspirin or warfarin, heparin, or DOAC. A Bonferroni correction was applied. RESULTS: On multivariable analysis, FVL patients were found to have increased odds of 90-day deep vein thrombosis (odds ratio (OR) = 9.20), pulmonary embolism (OR = 6.89), and aggregated severe and all adverse events (OR = 4.74 and 1.98, respectively), but not elevated risk of other perioperative adverse events or 5-year reoperations. More potent chemoprophylactic agents (warfarin, heparin, DOAC) reduced, but did not completely eliminate, the increased VTE risks (without increasing bleeding events). CONCLUSIONS: This study quantified the significantly elevated VTE risk associated with FVL patients undergoing THA. The lack of difference in other specific adverse events and 5-year reoperations is reassuring. Clearly, chemoprophylactic agents are important in this population and may need further attention.

Rare Coagulopathies in Hematologic Spotlight: Isolated Factor V Deficiency and Combined Factor V and VIII Deficiency.

Rare coagulation disorders pose significant diagnostic challenges emphasizing the importance of clinical vigilance and meticulous hemostatic workup for accurate diagnosis and timely management. We present two cases of exceptionally uncommon coagulopathies - isolated factor V deficiency (F5D) and combined factor V and VIII deficiency (F5F8D). Case 1 features a 24-year-old woman incidentally diagnosed with severe F5D during routine preoperative evaluation for an ovarian cyst. Despite the absence of any reported bleeding manifestations, a timely and accurate diagnosis was rendered. Perioperative management with fresh frozen plasma and postoperative monitoring ensured favorable surgical outcomes. Case 2 features a 10-year-old male presenting with prolonged gum bleeding. Following systematic hemostatic workup, a diagnosis of F5F8D was rendered, thereby guiding optimal therapeutic interventions. We herein aim to contribute valuable insights into the understanding of coagulation physiology and the diagnostic intricacies and management strategies of rare coagulation disorders.

A Case of Thoracic Aortic Mural Thrombus and Multiple Hypercoagulable Etiologies.

Thoracic aortic mural thrombi (TAMT) are rare yet a significant cause of emboli and mortality. Hypercoagulability is thought to play a role in pathogenesis. A common association is prothrombin G20210A mutation. We present a case of an 87-year-old man with an incidentally found TAMT in the setting of prothrombin mutation, metastatic prostate cancer, and a myeloproliferative disorder. The patient had several causes activating Virchow's hypercoagulability principle, contributing to a centrally located clot. Because of its paucity in the literature, we advocate for further research concerning treatment modalities of TAMTs as well as an additional and timely workup for hypercoagulable states to prevent further calamity.

Lower Limb Deep Venous Thrombosis After Posterior Spinal Fusion as an Initial Manifestation of Factor V Leiden Mutation in a Pediatric Patient: A Case Report.

Deep venous thrombosis (DVT) is a serious condition in which a blood clot forms in a deep vein, usually of the lower extremity. In pediatric orthopedic surgery, the incidence of thrombotic events is rare. This is a case presentation of a 12-year-old female patient without previous events or a family history of thrombotic events who underwent a posterior spinal fusion due to severe adolescent idiopathic scoliosis. The patient developed a DVT due to an underlying Factor V Leiden mutation. The purpose of this case report is to create awareness, facilitate the diagnosis and management, and aid in future interventions and clinical outcomes.

Paternal thrombophilia and recurrent implantation failure: an exploratory case-control study.

OBJECTIVE: Many pieces of literature have reported that inherited and acquired thrombophilia might be a risk factor for recurrent implantation failure (RIF), however, most studies have only focused on RIF patients and not their male partners. We studied the possible association of paternal thrombophilia with RIF risk. METHODS: Forty-two male partners aged 20-45 suffered from RIF compared with 42 males from couples with at least one successful pregnancy. All participants were investigated for thrombophilia markers. RESULTS: The prevalence of coagulation Factor V activity was significantly higher in the case group (42.9%) than in the control group (16.7%) (p=0.008) (OR=3.75; 95% CI, 1.38, 10.12). The prevalence of protein C and protein S deficiencies in RIF patients were 4.8% and 2.4%, respectively, and 0% in the controls. The prevalence of antithrombin III (ATIII) deficiency was significantly higher in the case group (19%) than in the control group (2.4%) (p=0.01). None of MTHFR C677T and MTHFR A1298C were statistically significant between the two groups. Combined thrombophilia was 45.2% in the men of the RIF group when compared with the control, 14.2% (p=0.001) (OR = 4.95; 95% CI, 1.75-13.86). CONCLUSIONS: Paternal thrombophilia may be related to recurrent implantation failure, so evaluation of this factor in RIF patients could be used to identify relevant risk groups and may help in the proper management of these cases to enhance the chance of implantation.

Membrane binding and lipid-protein interaction of the C2 domain from coagulation factor V.

Anchoring of coagulation factors to anionic regions of the membrane involves the C2 domain as a key player. The rate of enzymatic reactions of the coagulation factors is increased by several orders of magnitude upon membrane binding. However, the precise mechanisms behind the rate acceleration remain unclear, primarily because of a lack of understanding of the conformational dynamics of the C2-containing factors and corresponding complexes. We elucidate the membrane-bound form of the C2 domain from human coagulation factor V (FV-C2) by characterizing its membrane binding the specific lipid-protein interactions. Employing all-atom molecular dynamics simulations and leveraging the highly mobile membrane-mimetic (HMMM) model, we observed spontaneous binding of FV-C2 to a phosphatidylserine (PS)-containing membrane within 2-25 ns across twelve independent simulations. FV-C2 interacted with the membrane through three loops (spikes 1-3), achieving a converged, stable orientation. Multiple HMMM trajectories of the spontaneous membrane binding provided extensive sampling and ample data to examine the membrane-induced effects on the conformational dynamics of C2 as well as specific lipid-protein interactions. Despite existing crystal structures representing presumed "open" and "closed" states of FV-C2, our results revealed a continuous distribution of structures between these states, with the most populated structures differing from both "open" and "closed" states observed in crystal environments. Lastly, we characterized a putative PS-specific binding site formed by K23, Q48, and S78 located in the groove enclosed by spikes 1-3 (PS-specificity pocket), suggesting a different orientation of a bound headgroup moiety compared to previous proposals based upon analysis of static crystal structures.

Triple whammy in a patient with portal vein thrombosis.

Infection with SARS-CoV-2 has been shown to predispose to thromboembolic events. The risk of such thromboses further increases in those with underlying inherited or acquired prothrombotic states. The authors present a 30-year-old lady who developed acute abdominal pain, three days after recovery from a mild COVID-19 infection. She was also using oral contraceptive pills. Laboratory investigations revealed elevated inflammatory markers, and a contrast-enhanced abdominal CT scan demonstrated portal vein thrombosis (PVT). Due to the unusual site of thrombosis, a thrombophilia screen was performed, which detected a heterozygous Factor V Leiden mutation (FVL). Thus, her PVT was attributed three simultaneous risk factors, namely COVID-19 infection, OCP use and FVL mutation. She was initiated on anti-coagulation, with which she improved significantly. In patients presenting with thromboses at uncommon sites, investigation for evidence of recent Covid-19 infection and screening for inherited and acquired thrombophilia should be considered, while discontinuing any offending medications.

The Etiology of the Thrombotic Phenomena Involved in the Process of Coronary Artery Disease-What Is the Role of Thrombophilic Genes in the Development of This Pathology?

Cardiovascular diseases, among which includes coronary artery disease, represent one of the most important causes of mortality and morbidity worldwide. Research aimed at determining the risk factors involved recognizes a group of "traditional" risk factors, but also more recent studies identified over 100 "novel" ones which may have a role in the disease. Among the latter is the thrombophilia profile of a patient, a pathology well-established for its involvement in venous thromboembolism, but with less studied implications in arterial thrombosis. This paper reviews the literature, explaining the pathophysiology of the thrombophilia causes associated most with coronary thrombosis events. Results of several studies on the subject, including a meta-analysis with over 60,000 subjects, determined the significant involvement of factor V Leiden, prothrombin G20210A mutation, plasminogen activator inhibitor-1 and antiphospholipid syndrome in the development of coronary artery disease. The mechanisms involved are currently at different stages of research, with some already established and used as therapeutic targets.

A Novel Variant of the LMAN1 Gene in Combined Factor V and Factor VIII Deficiency in a Saudi Female Child: A Case Report.

Combined factor V and factor VIII deficiency (F5F8D) is an exceedingly rare autosomal recessive disease that causes concomitantly low levels of factor V and factor VIII, leading to mild to moderate bleeding tendencies. Within this disorder, mutations manifest in the lectin mannose-binding protein (LMAN1) or multiple coagulation factor deficiency 2 (MCFD2) genes. This report presents a case of a five-year-old Saudi female child who was referred from an otolaryngology clinic, with an incidental finding of prolonged prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (aPTT) detected during routine preoperative investigations for tonsillectomy, prompting further investigations. There was no prior history of bleeding symptoms in the patient. She was discovered to have low assays of factor V and factor VIII on subsequent investigations. Whole exome sequencing revealed the novel homozygous mutation c.604C>T in the LMAN1 gene, validating the diagnosis of F5F8D.

The Contribution of Inherited Thrombophilia to Venous Thromboembolism in Cancer Patients.

Although the relationship between venous thromboembolism (VTE) and cancer has been a subject of study, knowledge of the contribution of thrombophilia to thrombosis in patients with cancer is still very limited. The aim of this article is to collect present knowledge on the contribution of inherited thrombophilia to VTE in cancer patients. We performed a search in Google Scholar and PubMed and selected 21 from 76 returned articles. Then we made a narrative review of the selected articles. We describe 11 studies on the contribution of inherited thrombophilia to VTE in cancer patients in general and 10 on that contribution in specific types of cancer: 1 in colorectal cancer, 4 in breast cancer, 1 in gynecologic cancer and 4 in hematopoietic malignancies. All studies investigate the relation of factor V Leiden (FVL) to VTE, 13 that of the prothrombin G20210A mutation (PTG20210A) and 7 studies also investigate other inherited thrombophilias, such methylenetetrahydrofolate reductase gene mutations, although only 2 investigate the contribution of deficiencies of the natural anticoagulants. Studies are very heterogeneous, in design and sample size and conclusions differ considerably. There is no consensus on the contribution of inherited thrombophilia to VTE in cancer patients except for acute lymphoblastic leukemia in children. Probably, that contribution is not the same for all types of cancer and more studies are needed to bring more knowledge on this subject.

Total shoulder arthroplasty in patients with factor V Leiden.

BACKGROUND: Anatomic and reverse total shoulder arthroplasty (TSA) are effective treatment options for end-stage glenohumeral osteoarthritis. However, consideration for pre-existing conditions must be taken into account. Factor V Leiden (FVL), the most common inherited thrombophilia, is one such condition that predisposes to a prothrombotic state and may affect perioperative and longer-term outcomes following TSA. METHODS: Adult patients undergoing primary TSA for osteoarthritis indication were identified in the 2010 through October 2021 PearlDiver M157 database. Patients with or without FVL were matched at a 1:4 ratio based on age, sex, and Elixhauser Comorbidity Index. Ninety-day adverse events and 5-year revision rates were assessed and compared with multivariable logistic regression and rank-log tests, respectively. Finally, the relative use and bleeding/clotting outcomes were assessed based on venous thromboembolic (VTE) prophylactic agents used, with categories defined as (1) warfarin, heparin, or direct oral anticoagulant (DOAC) or (2) aspirin/no prescription found. RESULTS: Of 104,258 TSA patients, FVL was identified for 283 (0.27%). Based on matching, 1081 patients without FVL and 272 patients with FVL were selected. Multivariable analyses demonstrated that those with FVL displayed independently greater odds ratios (ORs) of deep vein thrombosis (DVT, OR = 9.50, P < .0001), pulmonary embolism (PE, OR = 10.10, P < .0001), and pneumonia (OR = 2.43, P = .0019). Further, these events contributed to the increased odds of aggregated minor (OR = 1.95, P = .0001), serious (OR = 6.38, P < .0001), and all (OR = 3.51, P < .0001) adverse events. All other individual 90-day adverse events, as well as 5-year revision rates, were not different between the study groups. When compared to matched patients without FVL on the same anticoagulant agents, FVL patients on warfarin, heparin, or DOAC agents demonstrated lesser odds of 90-day DVT and PE (OR = 4.25, P < .0001, and OR = 2.54, P = .0065) than those on aspirin/no prescription found (OR = 7.64 and OR = 21.95, P < .0001 for both). Interestingly, those on VTE prophylactic agents were not at greater odds of bleeding complications (hematoma or transfusion). DISCUSSION AND CONCLUSIONS: TSA patients with FVL present a difficult challenge to shoulder reconstruction surgeons. The current study highlights the strong risk of VTE that was reduced but still significantly elevated for those with stronger classes of VTE chemoprophylaxis. Acknowledging this risk is important for surgical planning and patient counseling, but also noted was the reassurance of similar 5-year revision rates for those with vs. without FVL.

Factor V Leiden, MTHFR, and FXIIIVal34Leu gene polymorphisms and their association with clinical features and risk of diabetic retinopathy in patients with type 2 diabetes.

Background: Diabetic retinopathy (DR) is expanding to epidemic levels globally due to the progressing prevalence of diabetes mellitus (DM). In this study, the association between factor V Leiden (FVL), MTHFRC677T, and FXIIIVal34Leu polymorphisms and diabetic retinopathy was investigated in Eastern Iran. Methods: This case-control study enlisted the participation of 300 people (diabetic patients=100, diabetic retinopathy patients=100, healthy controls=100), and polymorphisms were examined by Tetra primer ARMS-PCR. Results: The frequency of FVL (p=0.294) and FXIIIVal34Leu (P=0.349) polymorphism showed no significant results between the genotype frequency in the mentioned groups. In contrast, MTHFRC677T SNP was significantly different in diabetic patients and controls (P=0.008). The MTHFRC677T polymorphism was found to be connected with increased systolic blood pressure in patients who had the TT genotype (130.96±11.92mm/Hg; P=0.011). Conclusion: Our study recommended that the MTHFRC677T polymorphism may offer to DR development. Studies with larger sample sizes and a wider spectrum of populations are authorized to verify this finding.

Inpatient thrombophilia workup; does hematology consult prevent unnecessary testing?

Hypercoagulable disorders are best described as a group of acquired and hereditary conditions that increase the risk for the development of thrombi within veins or arteries. In the setting of an unprovoked venous thromboembolism, common practice in the inpatient setting has been further investigation via a thrombophilia workup to establish an underlying cause. Current Hematology-Oncology guidelines argue against inpatient workup as the results rarely influence inpatient management. Following American Society of Hematology guidelines (Middledorp), the current study found that only 15% (11/72) of patients met appropriate criteria for thrombophilia testing. There was no relationship between appropriate thrombophilia testing and diagnosis of thrombophilia or initiation of anticoagulation. There was a relationship between appropriate thrombophilia testing and Hematology-Oncology consultation. This demonstrates the need for expert consultation if thrombophilia testing is being considered. The current study provides more evidence that a strong recommendation against inpatient testing should be made as testing does not aid in diagnosis or change management and is an overutilization of healthcare resources.

Successful microvascular surgery in patients with thrombophilia in head and neck surgery: a case series.

BACKGROUND: In this case series, a perioperative anticoagulation protocol for microvascular head and neck surgery in patients with thrombophilia is presented. Microvascular free-flap surgery is a standard procedure in head and neck surgery with high success rates. Nevertheless, flap loss-which is most often caused by thrombosis-can occur and has far-reaching consequences, such as functional impairment, prolonged hospitalization, and increased costs. The risk of flap loss owing to thrombosis is significantly increased in patients with thrombophilia. Therefore, perioperative anticoagulation is mandatory. To date, no perioperative anticoagulation protocol exists for these high-risk patients. CASE PRESENTATION: We present three exemplary male Caucasian patients aged 53-57 years with free flap loss owing to an underlying, hidden thrombophilia. CONCLUSION: We present a modified anticoagulation protocol for microvascular surgery in these high-risk patients, enabling successful microsurgical reconstruction.