Antifibrinolytics in women with menorrhagia

Prophylaxis with low dose tranexamic acid in acute myeloid leukemia patients undergoing intensive chemotherapy

Patients suffering from acute myeloid leukemia (AML) carry a high risk of serious bleeding complications due to severe thrombocytopenia for long periods of time during treatment. Prior to prophylactic platelet transfusion becoming the standard of care, intracranial bleeding was a major contributor to death in AML patients. However, despite prophylactic platelet transfusions, up to 79% of patients with AML experience clinically significant bleeding during treatment. Antifibrinolytics are effective and well tolerated hemostatic agents widely used in many patient groups, and in this study, we investigated the effect of low dose tranexamic acid (TXA) in patients with AML and thrombocytopenia. We compared bleeding and thrombosis between 113 thrombocytopenic AML patients receiving TXA 500 mg three times daily (n = 36) versus no-TXA (n = 77). Clinical information was obtained systematically from electronic medical records, and laboratory data were collected from the laboratory information system. No difference was demonstrated in number of patients with at least one bleeding episode (TXA: 89% vs. no-TXA: 93%, p = 0.60), median number of bleeding days (TXA: 2.5 days vs. no-TXA 2.0 days, p = 0.30), bleeding location or transfusion needs between the two groups. However, platelet count was found to be a significant risk factor for bleeding, with a probability of bleeding of 35% with a platelet count below 5 × 109/L (logistic regression, p < 0.01). We found no difference in thromboembolic events between the two groups (TXA: 8% vs. no-TXA 10%, p = 0.99). In conclusion, treatment with low dose TXA is safe, but we found no evidence to suggest that it reduces bleeding in AML patients with thrombocytopenia.

Browplasminin, a condensed tannin with anti-plasmin activity isolated from an aqueous extract of Brownea grandiceps Jacq. flowers

ETHNOPHARMACOLOGICAL RELEVANCE

Following Venezuelan traditional medicine, females with heavy menstrual blood loss (menorrhagia) drink Brownea grandiceps Jacq. flowers (BG) decoctions to reduce the bleeding. In a previous study, we demonstrated that BG aqueous extract (E) possesses a potent anti-fibrinolytic activity capable of inhibiting plasmin, the main serine-protease that degrades fibrin. It is widely known that plasmin inhibitors are often used as anti-fibrinolytics to reduce bleeding during surgeries with high risk of blood loss such as cardiac, liver, vascular, tooth extraction and large orthopedic procedures, as well as for menorrhagia treatments. The aim of this work was to isolate and characterize from BGE the compound responsible for the reported anti-fibrinolytic activity.

MATERIALS AND METHODS

A decoction of BG was prepared; then it was homogenized, centrifuged and lyophilized to obtain BGE. Subsequently the extract was fractionated by gel filtration and reverse phase using HPLC and the active compound was characterized by MALDI-ToF MS. The kinetic parameters of anti-plasmin activity were evaluated by an amidolytic assay using a chromogenic substrate; also the anti-plasmin activity was estimated by fibrin plate method. Data were analyzed by nonparametric statistics.

RESULTS

The active compound was a condensed tannin denominated Browplasminin, which is capable of inhibiting the plasmin activity in a dose-dependent manner when measured in fibrin plates or by the amidolytic activity method; it also has a minor effect on the FXa activity. However, it does not affect the activity of other serine-proteases such as trypsin, t-PA or u-PA. Browplasminin consists predominately of heteroflavan-3-ols of catechin with B-type linkages, and extents up to heptadecamers (~ 5000Da), with hexose residues attached to the polymer that presents a high degree of galloylation. Its IC₅₀ for plasmin was 47.80μg/mL and for FXa was 237.08μg/mL, while the Ki were 0.76 and 61.61μg/mL for plasmin and FXa, respectively.

CONCLUSIONS

The overall outcome of this study suggests that Browplasminin could be responsible for reducing heavy menstrual bleeding in women because its kinetic parameters showed that is a good plasmin inhibitor.

Oral Tranexamic Acid versus Combined Oral Contraceptives for Adolescent Heavy Menstrual Bleeding: A Pilot Study

STUDY OBJECTIVE

To compare the efficacy of oral tranexamic acid (TA) with combined oral contraceptives (COC) in reducing menstrual blood loss (MBL) and improving quality of life in adolescent heavy menstrual bleeding (HMB).

DESIGN, SETTING, AND PARTICIPANTS

A prospective randomized crossover trial with 17 postmenarchal girls aged 21 years and younger with HMB who were seen at our institution.

INTERVENTIONS

Patients were randomized to group A (TA arm) or group B (COC arm), each for 3 cycles, with crossover to the second arm after 1-month washout.

MAIN OUTCOME MEASURES

The primary end points were difference in improvement in MBL and QOL, from baseline to end of each therapy.

RESULTS

Seventeen patients were enrolled (mean age 14.2 years, range 11.7 to 16.8 years). Nine patients completed both arms; 8 patients withdrew from the study due to adverse events or noncompliance. Compared with baseline, significant improvement (P < .05) was demonstrated by TA and COC in MBL (mean Pictorial Blood Assessment Chart score decrease: TA, 536.4; COC, 430.6) and quality of life (mean Pediatric Quality of Life Inventory(TM) version 4.0 Generic Scales score increase: TA, 15.6; COC, 16.75), but no significant difference was noted between TA and COC (P > .05). There was statistically significant reduction in the length of menstrual cycle for COC only (mean reduction 5.3 days; P = .04) and not for TA (P = .18). Ten patients (58%) experienced adverse events that were possibly drug related (TA: n = 3, 30%; COCP: n = 7, 64%).

CONCLUSION

In this pilot study, oral TA appeared as efficacious as COC in the management of adolescent HMB by reducing MBL and improving quality of life.

Aqueous extract from Brownea grandiceps flowers with effect on coagulation and fibrinolytic system

ETHNOPHARMACOLOGICAL RELEVANCE

Brownea grandiceps flowers are used in Venezuelan folk medicine as anti-hemorrhagic in women with heavy menstrual blood loss (menorrhagia). However, prior to this study, there were no scientific investigations to support this fact, because the aqueous extract from Brownea grandiceps flowers had not been previously evaluated neither phytochemically nor biologically. The objective of this work was to evaluate in vitro the effects of aqueous extract from Brownea grandiceps flowers on the coagulation system and fibrinolysis.

MATERIALS AND METHODS

An infusion of Brownea grandiceps flowers (160g) was performed; then, it was homogenized, centrifuged and lyophilized to obtain the aqueous extract, and this was called BGE. Subsequently, the extract was characterized on the one hand, phytochemically and on the other hand, biologically, employing prothrombin time (PT), partial thromboplastin time (PTT) and thrombin time (TT) to determine the effects on extrinsic, intrinsic and common coagulation pathways, respectively. In addition to that, the fibrinogenolytic and fibronectinase activity was evaluated by SDS-PAGE using Tris-Tricine system and analyzed by densitometric study utilizing ImageJ program. Also, by using specific chromogenic substrates for Factor Xa (FXa), thrombin, tissue plasminogen activator (t-PA), urokinase plasminogen activator (u-PA) and plasmin, it was assessed whether BGE exhibited some enzyme-like activity, and inhibitory activity of the afore mentioned enzymes. Fibrinolytic and antifibrinolytic activities were determined by a fibrin plate method. Data were analyzed by an nonparametric method.

RESULTS

BGE presented tannins, saponins, glycosides, alkaloids, flavonoids, coumarins, and did not contain triterpenoids and steroids. Also, BGE at low concentrations (250-1250µg/mL) reduced the PT, while higher concentrations (15000-25000µg/mL) prolonged this time. However, BGE concentrations between 1250 and 25000µg/mL prolonged the PTT. Prolongation of PT and PTT was observed at high concentrations and was due to FXa inhibitor found in BGE and this effect could be strengthened by degradation of fibrinogen and fibronectin, which were also produced by BGE. Moreover, BGE did not clot fibrinogen or human plasma, and neither did it cleave the chromogenic substrates specific to FXa nor thrombin. These results suggest the pro-coagulant components could be acting on some factor of the extrinsic pathway, since only PT was shortened. Furthermore, BGE did not hydrolyze the chromogenic substrate specific to plasmin, t-PA and u-PA nor did it produce fibrin degradation. However, all BGE concentrations tested inhibited the plasmin activity in a dose-dependent manner.

CONCLUSIONS

The outcomes of this study reveal the presence of fibrinogenolytic, fibronectinase and anti-FXa components in BGE, plus anti-plasmin compounds that could be acting as antifibrinolytic, thus delaying the fibrin degradation in pathophysiological processes, as it has been observed in women presenting with menorrhagia due to a high plasmin concentration. Where this anti-plasmin compound, along with pro-coagulant components also present in BGE, could be made responsible for reducing heavy menstrual bleeding in women, since a deficiency in one or more blood coagulation factors such as factor VII, V or X, is a potential cause of menorrhagia.

Recent advances on plasmin inhibitors for the treatment of fibrinolysis-related disorders

Growing evidence suggests that plasmin is involved in a number of physiological processes in addition to its key role in fibrin cleavage. Plasmin inhibition is critical in preventing adverse consequences arising from plasmin overactivity, e.g., blood loss that may follow cardiac surgery. Aprotinin was widely used as an antifibrinolytic drug before its discontinuation in 2008. Tranexamic acid and ε-aminocaproic acid, two small molecule plasmin inhibitors, are currently used in the clinic. Several molecules have been designed utilizing covalent, but reversible, chemistry relying on reactive cyclohexanones, nitrile warheads, and reactive aldehyde peptidomimetics. Other major classes of plasmin inhibitors include the cyclic peptidomimetics and polypeptides of the Kunitz and Kazal-type. Allosteric inhibitors of plasmin have also been designed including small molecule lysine analogs that bind to plasmin's kringle domain(s) and sulfated glycosaminoglycan mimetics that bind to plasmin's catalytic domain. Plasmin inhibitors have also been explored for resolving other disease states including cell metastasis, cell proliferation, angiogenesis, and embryo implantation. This review highlights functional and structural aspects of plasmin inhibitors with the goal of advancing their design.

Treatment of heavy menstrual bleeding of endometrial origin: randomized controlled trial of medroxyprogesterone acetate and tranexamic acid

PURPOSE

This study aimed at comparing the efficacy of medroxyprogesterone acetate (MPA) and tranexamic acid (TA) for treating heavy menstrual bleeding of endometrial origin (HMB).

METHODS

A randomized controlled trial was carried out in three gynecology clinics in Tehran, Iran. Ninety women with the HMB of endometrial origin were randomized into the study: 44 patients took MPA for 21 days from day 5 and 46 patients took tranexamic acid for 5 days from day 1 of menses for three consecutive menstrual cycles. Blood loss was measured using the pictorial blood loss assessment chart (PBAC); hematological assessments were made before intervention and after treatment. SF-36 and HMB Questionnaire (MQ) were given to assess quality of life. Statistical analysis was performed using t test, Paired t test, χ(2), Mann-Whitney, Wilcoxon signed-rank test, and repeated measure analysis.

RESULTS

PBLC mean score, duration of bleeding and Hb values as well as quality of life were significantly improved in both groups (P < 0.05). But there was no significant deference between groups. More drug complication and less satisfaction were reported by MPA group (P = 0.003 and P = 0.002, respectively).

CONCLUSIONS

Long-term use of MPA is as effective as Tranexamic acid in treating HMB and increasing quality of life. However, bleeding irregularity side effects of MPA might limit its use.

Crystal structure of the native plasminogen reveals an activation-resistant compact conformation

BACKGROUND

Plasminogen is the zymogen form of plasmin and the precursor of angiostatin. It has been implicated in a variety of disease states, including thrombosis, bleeding and cancers. The native plasminogen, known as Glu-plasminogen, contains seven domains comprising the N-terminal peptide domain (NTP), five kringle domains (K1-K5) and the C-terminal serine protease domain (SP). Previous studies have established that the lysine binding site (LBS) of the conserved kringle domains plays a crucial role in mediating the regulation of plasminogen function. However, details of the related conformational mechanism are unknown.

OBJECTIVES

We aim to understand in more detail the conformational mechanism of plasminogen activation involving the kringles.

METHODS

We crystallized the native plasminogen under physiologically relevant conditions and determined the structure at 3.5 Å resolution. We performed structural analyses and related these to the literature data to gain critical understanding of the plasminogen activation.

RESULTS AND CONCLUSIONS

The structure reveals the precise architecture of the quaternary complex. It shows that the Glu-plasminogen renders its compact form as an activation-resistant conformation for the proteolytic activation. The LBSs of all kringles, except K1, are engaged in intra-molecular interactions while only K1-LBS is readily available for ligand binding or receptor anchorage. The structure also provides insights into the interactions between plasminogen and α2-antiplasmin, the primary physiological inhibitor of plasmin. Furthermore, the data presented explain why a conformational transition to the open form is necessary for plasminogen activation as well as angiostatin generation, and provide a rationale for the functional hierarchy of the different kringles.

Adenomyosis: a challenge in clinical gynecology

Adenomyosis is a prevalent, benign gynecologic condition in which endometrial tissue invades the myometrium, causing myometrial inflammation and hypertrophy. Although some women with adenomyosis are asymptomatic, the condition often causes menorrhagia and dysmenorrhea. This article provides women's health providers with a review of causes and risk factors for developing adenomyosis, clinical presentations of women with the condition, diagnostic modalities and criteria, and medical and surgical treatment options.

Giant abdominopelvic haematoma arising from ovulation in a Glanzmann's thrombasthenia patient with platelet refractoriness: treatment with surgery and intra-abdominal tranexamic acid

Glanzmann's thrombasthenia (GT) is a very rare autosomal recessive genetic bleeding disorder. Women with coagulation abnormalities are at increased risk of corpus luteum rupture and haemoperitoneum. Here we present a severe case of GT resulting in a haematoma extending from the pelvis to the liver that could only be controlled by surgery and intra-abdominal tranexamic acid.