Plasma fibrin clot properties and cardiovascular mortality in patients with type 2 diabetes: a long-term follow-up study.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) are at high risk of cardiovascular mortality, but the mechanisms behind this remain unclear. Prothrombotic fibrin clot properties have been shown in T2DM and cardiovascular disease. We hypothesized that formation of denser clots, which are resistant to fibrinolysis, has a negative impact on cardiovascular mortality in T2DM. METHODS: We studied 133 T2DM patients aged 43-83 years. Plasma fibrin clot turbidity, permeation, compaction, and efficiency of clot lysis using 3 assays including the determination of maximum concentration (D-Dmax) and rate of increase in D-dimer concentration (D-Drate) released during tissue plasminogen activator-induced degradation, were evaluated at the time of enrollment, along with thrombin generation and fibrinolytic proteins. During a median follow-up period of 72 months, cardiovascular mortality was recorded. RESULTS: Cardiovascular deaths (n = 16, 12%) occurred more frequently in patients with increased D-Dmax (> 4.26 mg/l, hazard ratio [HR] 5.43, 95% confidence interval [CI] 1.99-14.79), or decreased D-Drate (< 0.07 mg/l/min, HR 2.97, 95% CI 1.07-8.23), or increased peak thrombin (> 283.5 nM, HR 5.65, 95% CI 2.07-15.51). These predictors had an even more potent impact on cardiovascular mortality in patients with prior cardiovascular disease (64.7%) and with corresponding risks as follows: HR 6.18, 95% CI 2.02-18.96; HR 8.98, 95% CI 2.99-26.96; and HR 5.35, 95% CI 1.62-17.72, respectively. Other investigated fibrin variables and fibrinolytic proteins did not associate with cardiovascular mortality. In multivariable analysis, cardiovascular mortality was predicted by D-Dmax > 4.26 mg/l, age > 65 years, prior cardiovascular disease, and C-reactive protein > 3 mg/l. CONCLUSIONS: This study is the first to show that formation of denser fibrin clots resistant to fibrinolysis could be a risk factor for long-term cardiovascular mortality in T2DM.

Glycation and acetylation sites on fibrinogen in plasma fibrin clot of patients with type 2 diabetes: Effects of low-dose acetylsalicylic acid.

Acetylsalicylic acid (ASA) and type 2 diabetes mellitus (T2DM) affect fibrin clot properties through fibrinogen acetylation or glycation. We aimed to identify glycation and acetylation sites on fibrinogen in plasma fibrin clot of T2DM patients with respect to effects of ASA and fibrin clot properties. In fibrin clots generated from plasma of 9 T2DM patients, we performed mass-spectrometric analysis of Nε-fructosyl-(FL), Nε-carboxyethyl-(CEL) and Nε-carboxymethyl-lysine (CML), and acetylation sites, before and after one-month administration of 75 mg/d ASA confirmed with determination of thromboxane B2 concentration (TXB2), along with clot permeability and lysis time, and thrombin generation. In the proteomic analysis, 216 proteins were identified. Among 10 glycation sites identified in α, 10 in ß and 6 in γ fibrinogen chain, there were 17 FL, 5 CEL and 4 CML sites. Some of glycation sites in fibrinogen were previously reported to be involved in cross-linking by factor XIII (αK-208, αK-448 and αK-539) and plasmin cleavage (αK-81). There were 7 acetylation sites in α and ß chains, and none in fibrinogen γ chain. Two acetylation sites were identical with FL sites (αK-195 and ß-247), while one with CML site (ßK-353). In 7 patients with low post-ASA TXB2, intensity of acetylation, as well as clot properties were unaffected by ASA. This study identifies glycation and acetylation sites on fibrinogen in plasma fibrin clot of T2DM and supports the view that low-dose ASA does not increase fibrinogen acetylation in T2DM. Our findings suggest that glycation may block sites previously identified to be acetylated in vitro.

Plasma fibrin clot proteomics in patients with acute pulmonary embolism: Association with clot properties.

It has been reported that 476 proteins can be detected in plasma fibrin clots from patients with venous thromboembolism. Plasma fibrin clots proteomic composition in relation to their properties has not been studied in acute pulmonary embolism (PE). Clots generated from plasma of 20 PE patients and 20 healthy controls were assessed using mass spectrometry, clot permeability (Ks), and clot lysis time (CLT). The proteomic composition of plasma fibrin clots from acute PE patients differed from that of control subjects in regard to 198 clot-bound proteins. In the acute PE group, we observed increased clot-bound fibrinogen, apolipoprotein B-100, platelet glycoprotein Ib, lipopolysaccharide-binding protein, and histones H3 + 4 and reduced fibronectin, α2-antiplasmin, α2-macroglobulin, factor (F)XIII, histidine-rich glycoprotein, antithrombin, von Willebrand Factor, plasminogen, and prothrombin. Among PE patients, low Ks (≤3.83 × 10-9 cm2) was associated with increased clot-bound C-reactive protein, kininogen-1, protein S, ß-2-microglobulin, and thromboxane-A synthase when compared with patients having Ks > 3.83 × 10-9 cm2. Ks correlated inversely with FIX and FV, thrombin-activatable fibrinolysis inhibitor, complement C1s, C7, C8, and apolipoprotein A-I. The specific protein composition in plasma fibrin clots from acute PE patients is associated with denser clot formation. Several proteins unrelated to the coagulation system can modulate fibrin phenotype in acute thrombotic states. SIGNIFICANCE: Our study significantly advances the field of thrombosis and hemostasis. The plasma fibrin clot proteomics findings fill the gap of knowledge about the presence and the role of other proteins to the plasma fibrin clot in the acute phase of pulmonary embolism, aside fibrinogen, which is the main component of fibrin. The reported methodology, which involves the sample preparation using Multienzyme Digestion-Filter Aided Sample Preparation (MED FASP), data acquisition with the Quadrupole-Orbitrap mass spectrometer, and data analysis using the advanced tools such as MaxQuant, Total Protein Approach and Perseus, allows to gain not only the qualitative, but also the quantitative insights into the microworld of proteins entangled among the fibrin network. By comparing the clots formed from plasma of patients with acute pulmonary embolism with the clots from healthy control, we provide the specific protein composition associated with unfavorable clot properties observed in this disease. Moreover, our findings emphasize that several proteins unrelated to the coagulation system, can modulate fibrin phenotype in acute thrombotic states.

Sex-specific alteration to α2-antiplasmin incorporation in patients with type 2 diabetes.

BACKGROUND: Type 2 diabetes mellitus (T2DM) is associated with hypofibrinolysis and increased factor XIII-mediated α2-antiplasmin incorporation into the fibrin clot. It is unclear whether there are sex-related differences in α2-antiplasmin incorporation in relation to impaired clot lysis in T2DM. AIM: We investigated α2-antiplasmin incorporation into fibrin clots as a determinant of clot lysability in patients of both sexes with T2DM. METHODS: In a group of 113 T2DM patients, 54 (47.8%) of which were women, we investigated α2-antiplasmin incorporation using an in-house sandwich enzyme-linked immunoassay and plasma clot lysis by turbidimetry, along with fibrinogen and thrombin generation using calibrated automated thrombogram and factor XIII activity. RESULTS: Female patients had 15.2% greater α2-antiplasmin incorporation into the fibrin clot (p = 0.008) and slightly higher plasma α2-antiplasmin concentration (p = 0.005) along with 8.4% longer time to 50% lysis (Lys50MA, p = 0.012) compared with men. Female patients had enhanced thrombin generation represented by shorter lag phase (p = 0.042), shorter time to peak (p = 0.033), and higher endogenous thrombin potential (p = 0.003) compared with men, while factor XIII activity was comparable between sexes (p = 0.085). On multivariate regression, patient sex and glycated hemoglobin (HbA1c) level were the predictors of α2-antiplasmin incorporation in the entire patient group, while α2-antiplasmin incorporation was associated with Lys50MA, as were fibrinogen, male sex and body-mass index. CONCLUSIONS: This study suggests that a more compromised fibrinolysis in diabetic women when compared with men could be in part mediated by increased α2-antiplasmin incorporation into the fibrin.

Identification of glycated and acetylated lysine residues in human α2-antiplasmin.

BACKGROUND: The post-translational protein modification via lysine residues can significantly alter its function. α2-antiplasmin, a key inhibitor of fibrinolysis, contains 19 lysine residues. AIM: We sought to identify sites of glycation and acetylation in human α2-antiplasmin and test whether the competition might occur on the lysine residues of α2-antiplasmin. METHODS: We analyzed human α2-antiplasmin (1) untreated; (2) incubated with increasing concentrations of ß-d-glucose (0, 5, 10, 50 mM); (3) incubated with 1.6 mM acetylsalicylic acid (ASA) and (4) incubated with 1.6 mM ASA and 50 mM ß-d-glucose, using the ultraperformance liquid chromatography system coupled to mass spectrometer. RESULTS: Eleven glycation sites and 10 acetylation sites were found in α2-antiplasmin. Incubation with ß-d-glucose was associated with glycation of 4 (K-418, K-427, K-434, K-441) out of 6 lysine residues, known to be important for mediating the interaction with plasmin. Glycation and acetylation overlapped at 9 sites in samples incubated with ß-d-glucose or ASA. Incubation with concomitant ASA and ß-d-glucose was associated with the decreased acetylation at all sites overlapping with glycation sites. At K-182 and K-448, decreased acetylation was associated with increased glycation when compared with α2-antiplasmin incubated with 50 mM ß-d-glucose alone. Although K-24 located in the proximity of the α2-antiplasmin cleavage site, was found to be only acetylated, incubation with ASA and 50 mM ß-d-glucose was associated the absence of acetylation at that site. CONCLUSION: Human α2-antiplasmin is glycated and acetylated at several sites, with the possible competition between acetylation and glycation at K-182 and K-448. Our finding suggests possibly relevant alterations to α2-antiplasmin function at high glycemia and during aspirin use.

Bleeding predictors in patients following venous thromboembolism treated with vitamin K antagonists: Association with increased number of single nucleotide polymorphisms.

INTRODUCTION: Single nucleotide polymorphisms (SNP) in genes encoding proteins involved in metabolism and action of vitamin K antagonists (VKA) affect anticoagulation stability. We investigated how those polymorphisms influence bleeding rates in patients following venous thromboembolism (VTE). MATERIALS AND METHODS: In 324 patients following unprovoked VTE, 143 (44%) on warfarin and 181 (56%) on acenocoumarol, we recorded bleeds within the preceding 24 months. We assessed eight SNP, including those in cytochrome P450 isoform 2C9 (CYP2C9) and isoform 4F2 (CYP4F2), vitamin K epoxide reductase complex subunit 1 (VKORC1), gamma-glutamyl carboxylase (GGCX), apolipoprotein E (APOE) and multidrug resistance gene 1 (MDR1). RESULTS: Within 48 months before enrolment, bleeding events occurred in 80 (25%) patients, including 14 (4%) major bleeds. Patients with bleeds had 16.2% lower median time in therapeutic range (TTR) and were more often carriers of CYP2C9*3 variant (26 [33%] vs. 19 [8%], p < 0.001) compared with the remainder. Bleeding occurred more frequently in patients with ≥4 SNP compared with the remainder (27 [34%] vs. 47 [19%], p = 0.009) with no intergroup differences of TTR. Number of SNP was one of the predictors of any bleeding. The regression model for major bleeding including factors such as CYP2C9*3 c. 1075 C, VKORC1 c. -1639 A and APOE c. 388 C showed good predictive ability (area under the curve - 0.79). CONCLUSIONS: In VTE patients on the maintenance treatment with VKA, bleeding episodes are associated with CYP2C9 gene variations and increased number of SNP of genes involved in the action and metabolism of VKA.

Interplay between elevated cellular fibronectin and plasma fibrin clot properties in type 2 diabetes.

Type 2 diabetes is associated with faster formation of poorly lysable, denser fibrin clots and elevated cellular fibronectin (cFn), a marker of vascular injury. We investigated whether cFn affects clot properties in type 2 diabetes. In 200 consecutive patients with type 2 diabetes and 100 control subjects matched for age and sex, we determined plasma cFn along with clot formation and degradation using turbidimetric and permeability assays. Diabetic patients had elevated cFn (median, 3.99 [interquartile range, 2.87-4.81] µg/ml]), increased clot density (MaxAbsC) and prolonged lysis time (LysT) compared with those without type 2 diabetes (all p<0.01). Diabetic patients with documented cardiovascular disease (CVD, n=127, 63.5 %) had increased cFn (4.53 [3.68-4.95] µg/ml), decreased clot permeability (Ks) and increased MaxAbsC compared with those without CVD (all p<0.001). Diabetic patients with cFn in the top quartile (>4.81 µg/ml) were two times more likely to have CVD compared with those in the lowest quartile (odds ratio 1.80, 95 % confidence interval 1.41-2.46, p<0.001). No differences in cFn were observed in relation to microvascular complications. After adjustment for potential confounders, cFn accounted for 10.2 % of variance in Ks, 18.2 % of variance in clot density and 10.2 % of variance in AUC in diabetic patients. This study shows that elevated cFn is associated with unfavourably modified clot properties in type 2 diabetes, especially with concomitant CVD, which indicates novel links between vascular injury and prothrombotic alterations in diabetes. Coagulation, cellular fibronectin, type 2 diabetes, cardiovascular disease.

Prediction of unstable anticoagulation with acenocoumarol versus warfarin in atrial fibrillation.

BACKGROUND: The SAMe-TT2R2 (sex female, age, medical history, treatment, tobacco use, race) score was developed in patients with atrial fibrillation (AF) on warfarin. The present study aimed to 1) compare the anticoagulation quality and management of AF patients treated with warfarin with those on acenocoumarol and 2) optimize the SAMe-TT2R2 score to detect AF patients at high risk of unstable anticoagulation with acenocoumarol and warfarin. METHODS: In a single-center retrospective study, 320 patients with AF, including 15 (5%) after valve replacement, aged 40-82 (median 70) years, including 203 (63%) receiving acenocoumarol and 117 (37%) treated with warfarin, were studied. The SAMe-TT2R2 score was modified based on the candidate factors retrieved from univariate regression and assessed using the receiver operating curves (ROC). RESULTS: A median SAMe-TT2R2 score was 2 (1-3). Proportions of patients with ≥ 2 points and 0-1 points in the SAMe-TT2R2 score who had the time in therapeutic range (TTR) ≤ 70% were similar (61 [67%] vs. 63 [56%], p = 0.11). A modified score, involving medical history (myocardial infarction [MI] and chronic obstructive pulmonary disease [COPD], 1 point), statin treatment (1 point) and tobacco use (2 points) had a higher area under the curve (AUC) in patients on acenocoumarol compared to SAMe- TT2R2 (0.66; 95% confidence interval 0.58-0.73 vs. 0.56; 0.48-0.64, p = 0.042); ≥ 1 point indicated TTR > 70% with a sensitivity and specificity of 61% and 63%, respectively. CONCLUSIONS: The SAMe-TT2R2 score is less effective in predicting unstable anticoagulation with acenocoumarol versus warfarin. Adding statin use and highlighting COPD and previous MI increases a predictive value of this score for acenocoumarol.

Heavy menstrual bleeding in women treated with rivaroxaban and vitamin K antagonists and the risk of recurrent venous thromboembolism.

Anticoagulants increase the risk of heavy menstrual bleeding (HMB). We sought to investigate the incidence, predictors and management of HMB in women on rivaroxaban compared to those on vitamin K antagonists (VKA). We addressed the issue as to whether HMB is associated with VTE recurrences. We performed a single-center prospective study in menstruating women aged 18-55years treated with rivaroxaban or VKA≥3months since the index VTE episode. Seventy six women on rivaroxaban and 45 patients on VKA were included. Patients on rivaroxaban more commonly reported HMB compared with those on VKA (31 [41%] vs. 8 [18%], p=0.009). Women treated with rivaroxaban more frequently needed interventions to reduce menstruation compared with those on VKA (29 [38%] vs. 6 [13%], p=0.004). During the median follow-up time of 13months, there were 8 (11%) recurrent VTE on rivaroxaban and 3 (7%) on VKA (p=0.5). Rivaroxaban treatment predisposed to HMB (odds ratio [OR] 3.2, 95% [confidence interval] CI 1.4-8.2, p=0.007) and the interruption of anticoagulant treatment for 2-3days (OR 3.2, 95% CI 1.1-11.6, p=0.033). HMB during the rivaroxaban treatment predisposed to recurrent VTE (OR 5.3, 95% CI 1.1-33.3, p=0.038). In menstruating women following VTE, rivaroxaban is associated with a two-fold higher risk of HMB compared with VKA. HMB predisposes to recurrent VTE episode, most likely due to the short interruptions of anticoagulation.

Single-agent MOR208 salvage and maintenance therapy in a patient with refractory/relapsing diffuse large B-cell lymphoma: a case report.

BACKGROUND: Diffuse large B-cell lymphoma is the most common subtype of non-Hodgkin's lymphoma. Standard first-line treatment for this aggressive subtype comprises the anti-CD20 antibody rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone. If patients receiving such treatment have an early relapse, or their disease is initially refractory to such treatment, standard salvage regimens may not be effective. There is therefore a high unmet clinical need for new targeted agents that might improve the outcome for such patients. CD19 is a B-lymphocyte lineage-specific cell surface antigen that is expressed by most B-cell non-Hodgkin's lymphomas. MOR208 is an fragment-crystallizable engineered humanized monoclonal antibody with enhanced antitumor activity that targets CD19 and that may consequently have clinical utility in this setting. CASE PRESENTATION: We describe the case of a 33-year-old Caucasian man who presented with a 3-month history of general symptoms and who was admitted to our pulmonology ward with dyspnea due to pneumonia and severe anemia. A histopathological examination of an enlarged right suprasternal lymph node confirmed a diagnosis of T-cell/histiocyte-rich large B-cell lymphoma, an uncommon morphological variant of diffuse large B-cell lymphoma. Our patient had a complete response to first-line rituximab combined with cyclophosphamide, doxorubicin, vincristine, and prednisone, but had an early relapse 5 months after the end of treatment. After intensive salvage therapy consolidated with an autologous stem-cell transplant, our patient again had an early relapse and was subsequently enrolled in a phase IIa trial of single-agent MOR208. Following a scheduled 3 months of weekly treatment, a partial response was confirmed and MOR208 was continued as maintenance therapy, with administration every second week. Positron emission tomography-computed tomography confirmed a complete response 9 months later. This response is ongoing, with a duration of 24 months. MOR208 was well-tolerated by our patient and his quality of life and performance status remain high. No hospitalizations were required and our patient engaged in full-time work and physical activities. CONCLUSION: Third-line single-agent therapy with the CD19 antibody MOR208 was highly effective in this patient, despite a history of early relapse after standard first-line and second-line treatment regimens. These data provide support for future randomized studies of MOR208.