Menorrhagia due to a qualitative deficiency of plasminogen activator inhibitor-1: case report and literature review

Prostaglandin E2 regulates the plasminogen activator pathway in human endometrial endothelial cells: a new in vitro model to investigate heavy menstrual bleeding

OBJECTIVE

To study the role of PGE2 in regulating plasminogen activator inhibitor-1 (PAI-1) and tissue plasminogen activator (tPA) in human primary endometrial endothelial cells (HEECs) from women with normal menstrual bleeding (NMB) and heavy menstrual bleeding (HMB).

DESIGN

In vitro study using endometrial endothelial cells.

SETTING

Research laboratory setting.

PATIENTS

Women with NMB and HMB provided endometrial biopsy samples.

INTERVENTIONS

Prostaglandin E2 and PGE2 receptor-selective agonists were administered to cultured HEECs.

MAIN OUTCOME MEASURES

Levels of PAI-1 and tPA in NMB-HEECs and HMB-HEECs after treatment with PGE2 and receptor-selective agonists.

RESULTS

Prostaglandin E2 increased total PAI-1 levels in NMB-HEECs, but not in HMB-HEECs, which had higher baseline PAI-1 levels. PGE2 receptors (PTGER)1 and PTGER2 agonists increased PAI-1 in NMB-HEECs, whereas PTGER3 and PTGER4 did not. Prostaglandin E2 had no effect on tPA levels in either NMB-HEECs or HMB-HEECs.

CONCLUSIONS

Prostaglandin E2, through PTGER1 and PTGER2, regulates the plasminogen activator system in NMB-HEECs, suggesting a role in reducing fibrinolytic activity during normal menstrual cycles. The lack of PGE2 effect and elevated baseline PAI-1 in HMB-HEECs support using this in vitro model to further understand prostaglandin pathways in NMB and HMB.

Clinical changes of leptin/ghrelin and PAI-1 levels in adolescent girls with abnormal uterine bleeding-ovulatory dysfunction

OBJECTIVE

To observe and compare the expression of energy regulators (leptin/ghrelin) and PAI-1 in girls with abnormal uterine bleeding-ovulatory dysfunction (AUB-O) and healthy adolescent girls.

METHODS

A total of 80 adolescent girls were studied including 60 with AUB-O and 20 healthy girls. All the general characteristics of subjects including height, weight, age, and age at menarche were collected after consent. The concentration of plasma leptin, ghrelin, PAI-1, and sex hormones was examined using enzyme-linked immunosorbent assay (ELISA) and DXI800 Access immunoassay system respectively.

RESULTS

Two groups were comparable in the age at menarche, visiting age, postmenarchal years, and BMI SDS (p > .05). Levels of leptin (11.12 ± 4.96 ng/ml vs. 18.59 ± 13.22 ng/ml, p < .001) and PAI-1 (116.40 ± 36.63 ng/ml vs. 173.19 ± 52.44 ng/ml, p < .001) in girls with AUB-O were significantly lower than that in healthy girls, and the levels of ghrelin were significantly higher than that in healthy girls (1.52 ± 4.20 ng/ml vs. 0.43 ± 0.64 ng/ml, p = .01). At the same time, we also found that girls with AUB-O showed negative correlation between the level of leptin, ghrelin, and estradiol.

CONCLUSIONS

Energy metabolism and coagulation might play a role in the development of AUB-O in adolescent girls.

Inherited disorders of the fibrinolytic pathway

Deficiencies or excessive activation of the  fibrinolytic system can result in severe, lifelong bleeding disorders. The most severe clinical phenotype is caused by α2-Antiplasmin (α2-AP) deficiency which results in excess fibrinolysis due to the inability to inhibit plasmin. Another bleeding disorder due to a defect in the fibrinolytic pathway results from Plasminogen activator inhibitor-1 (PAI-1) deficiency causing enhanced fibrinolysis due to the decreased inhibition of plasminogen activators resulting in increased conversion of plasminogen to plasmin. Both these disorders are rare and have an autosomal recessive pattern of inheritance. They can remain undetected as routine coagulation and platelet function tests are normal. A unique gain-of-function defect in fibrinolysis causes the Quebec platelet disorder (QPD) which is characterized by profibrinolytic platelets containing increased urokinase-type plasminogen activator (uPA) in the α-granules. A high index of suspicion based on clinical phenotype along with the availability of specialized hemostasis testing is required for timely and accurate diagnosis. Antifibrinolytic agents, such as tranexamic acid or ε-aminocaproic acid, are the mainstays of treatment which inhibit fibrinolysis by preventing the binding of plasminogen to fibrin and thereby stabilizing the fibrin clot. The purpose of this review is to summarize the pathogenesis, clinical phenotype, approaches to diagnosis and treatment for these three major disorders of fibrinolysis.

The use of prophylaxis in the treatment of rare bleeding disorders

Rare bleeding disorders (RBDs) are a heterogeneous group of coagulation factor deficiencies that include fibrinogen, prothrombin, α₂-antiplasmin, plasminogen activator inhibitor-1, and factors II, V, V/VIII, VII, X, XI and XIII. The incidence varies based upon the disorder and typically ranges from 1 in 500,000 to 1 per million population. Symptoms vary with the disorder and residual level of the clotting factor, and can range from relatively minor such as epistaxis, to life threatening, such as intracranial hemorrhage. Rapid treatment of bleeding episodes in individuals with severe bleeding phenotypes is essential to preserve life or limb and to prevent long-term sequelae; therapeutic options depend on the deficiency and range from plasma-derived (eg, fresh frozen plasma, prothrombin complex concentrates, factor X concentrate) to highly purified and recombinant single factor concentrates. The rarity of these disorders limits the feasibility of conventional prospective clinical trials; instead, clinicians rely upon registries, published case reports/series and experience to guide treatment. In some disorders, long-term prophylactic therapy is administered in response to the bleeding phenotype in an individual patient or based on the known natural history and severity of the deficiency. Intermittent prophylaxis, surrounding surgery, pregnancy, labor, and menstruation may be required to prevent or control excessive bleeding. This review summarizes therapeutic options, guidelines, recommendations and observations from the published literature for long-term, surgical, gynecological, and obstetric prophylaxis in deficiencies of fibrinogen; prothrombin; factors II, V, V/VIII, VII, X, XI and XIII; combined vitamin-K dependent factors; α2-antiplasmin; and plasminogen activator inhibitor 1. Platelet disorders including Glanzmann's thrombasthenia and Bernard-Soulier syndrome are also addressed.

Hemorrhagic disorders of fibrinolysis: a clinical review

Hyperfibrinolytic bleeding can be caused by a deficiency of one of the inhibitors of fibrinolysis (plasminogen activator inhibitor type 1 [PAI-1] or α2-antiplasmin [α2-AP]), or an excess of one of the activators of fibrinolysis: tissue-type plasminogen activator or urokinase-type plasminogen activator. This review focuses on the clinical implications of these disorders. The bleeding phenotype of fibrinolytic disorders is characterized by delayed bleeding after trauma, surgery and dental procedures. Bleeding in areas of high fibrinolytic activity is also common, such as menorrhagia and epistaxis. Patients with α2-AP deficiency present with the most severe bleeding episodes. Recently, it was discovered that hyperfibrinolytic disorders are associated with a high rate of obstetric complications such as miscarriage and preterm birth, especially in PAI-1 deficient patients. Hyperfibrinolytic disorders are probably underdiagnosed because of lack of knowledge and lack of accurate diagnostic tests. A substantial part of the large group of patients diagnosed as 'bleeding of unknown origin' could actually have a hyperfibrinolytic disorder. In the case of a high index of suspicion (i.e. because of a positive family history, recurrent bleeding or uncommon type of bleeding such as an intramedullary hematoma), further testing should not be withheld because of normal results of standard hemostatic screening assays. Timely diagnosis is important because these disorders can generally be treated well with antifibrinolytic agents.

Increased plasma clot permeability and susceptibility to lysis are associated with heavy menstrual bleeding of unknown cause: a case-control study

BACKGROUND

Formation of compact and poorly lysable clots has been reported in thromboembolic disorders. Little is known about clot properties in bleeding disorders.

OBJECTIVES

We hypothesized that more permeable and lysis-sensitive fibrin clots can be detected in women with heavy menstrual bleeding (HMB).

METHODS

We studied 52 women with HMB of unknown cause and 52 age-matched control women. Plasma clot permeability (Ks), turbidity and efficiency of fibrinolysis, together with coagulation factors, fibrinolysis proteins, and platelet aggregation were measured.

RESULTS

Women with HMB formed looser plasma fibrin clots (+16% [95%CI 7-18%] Ks) that displayed lower maximum absorbancy (-7% [95%CI -9 - -1%] ΔAbsmax), and shorter clot lysis time (-17% [95%CI -23 - -11%] CLT). The HMB patients and controls did not differ with regard to coagulation factors, fibrinogen, von Willebrand antigen, thrombin generation markers and the proportion of subjects with defective platelet aggregation. The patients had lower platelet count (-12% [95%CI -19 - -2%]), tissue plasminogen activator antigen (-39% [95%CI -41 - -29%] tPA:Ag), and plasminogen activator inhibitor-1 antigen (-28% [95%CI -38 - -18%] PAI-1:Ag) compared with the controls. Multiple regression analysis upon adjustment for age, body mass index, glucose, and fibrinogen showed that decreased tPA:Ag and shortened CLT were the independent predictors of HMB.

CONCLUSIONS

Increased clot permeability and susceptibility to fibrinolysis are associated with HMB, suggesting that altered plasma fibrin clot properties might contribute to bleeding disorders of unknown origin.

Functional stability of plasminogen activator inhibitor-1

Plasminogen activator inhibitor-1 (PAI-1) is the main inhibitor of plasminogen activators, such as tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA), and a major regulator of the fibrinolytic system. PAI-1 plays a pivotal role in acute thrombotic events such as deep vein thrombosis (DVT) and myocardial infarction (MI). The biological effects of PAI-1 extend far beyond thrombosis including its critical role in fibrotic disorders, atherosclerosis, renal and pulmonary fibrosis, type-2 diabetes, and cancer. The conversion of PAI-1 from the active to the latent conformation appears to be unique among serpins in that it occurs spontaneously at a relatively rapid rate. Latency transition is believed to represent a regulatory mechanism, reducing the risk of thrombosis from a prolonged antifibrinolytic action of PAI-1. Thus, relying solely on plasma concentrations of PAI-1 without assessing its function may be misleading in interpreting the role of PAI-1 in many complex diseases. Environmental conditions, interaction with other proteins, mutations, and glycosylation are the main factors that have a significant impact on the stability of the PAI-1 structure. This review provides an overview on the current knowledge on PAI-1 especially importance of PAI-1 level and stability and highlights the potential use of PAI-1 inhibitors for treating cardiovascular disease.

Rare bleeding disorders in young women

Rare bleeding disorders can cause significant bleeding in children and adolescents. These encompass rare clotting factor deficiencies, and fibrinolytic pathway defects. Vascular anomalies can cause recurrent and refractory bleeding, and are included in this review of rare causes of abnormal bleeding in children and adolescents. Menorrhagia is often reported as a manifestation of these conditions. Succinct knowledge about these disorders, their clinical presentation, diagnostic work-up, and therapeutic options are crucial to the accurate diagnosis and optimal management of affected patients. This review provides an overview of these infrequently encountered disorders, discusses their recognition based on results of suggested screening tests and offers a general guideline for approach to therapy.

Bleeding diathesis is associated with an A15T heterozygous mutation in exon 2 of the plasminogen activator inhibitor type 1

In the present study, we present a 60-year-old woman of American Indian descent with a life-long history of bleeding diathesis. She had a history of recurrent and prolonged bleeding such as mild epistaxis, gingival bleeding and microscopic hematurias. She also experienced a severe bleeding event after surgery. The patient had a large family with a history of a tendency of bleeding, severe in some cases. Hemostatic screening studies revealed no abnormalities, which could explain the bleeding tendency. Clot formation of sodium-citrated blood was analyzed by thromboelastography, which suggested a low platelet count or plasminogen activator inhibitor-1 (PAI-1) deficiency. However, her platelet count was slightly elevated. Subsequent sequencing of the PAI-1 gene revealed a heterozygous Ala15Thr mutation in the signal peptide. This type of deficiency is related to dynamics of PAI-1 secretion rather than its low levels or activity. We concluded that the PAI-1 mutation was likely the etiology of the bleeding diathesis in this patient.

A NOVEL ASSOCIATION BETWEEN A CHRONIC SUBDURAL HEMATOMA AND A FIBRINOLYTIC PATHWAY DEFECT

OBJECTIVE

Chronic subdural hematoma (CSDH) is a common form of intracranial hemorrhage that is known to recur in up to one-fifth of treated patients. We present a patient with recurrent CSDH who was found to have a defect in the fibrinolytic pathway, which may be a novel explanation for recurrent CSDH. This defect, deficiency of plasminogen activator inhibitor type I (PAI-1), should be recognized as a possible cause of CSDH.

CLINICAL PRESENTATION

A 49-year-old man presented with a CSDH, which recurred each time after 2 initially-effective craniotomies.

INTERVENTION

A deficiency of PAI-1 was diagnosed after the second recurrence. We hypothesize that this defect in the fibrinolytic system contributed to the recurrent hematoma. Treatment with aminocaproic acid led to resolution of the CSDH.

CONCLUSION

PAI-1 deficiency should be considered in patients with recurrent CSDH that lack another compelling explanation, particularly in patients with a family history of bleeding diatheses. PAI-1 deficiency can be identified by measuring plasma levels and can be treated with an oral course of aminocaproic acid.

Low PAI-1 activity in relation to inflammatory parameters, insulin profile and body mass index

BACKGROUND AND OBJECTIVE

High plasminogen activator inhibitor type 1 (PAI-1) activity is associated with inflammatory reactions and insulin resistance, but it is unclear what regulates PAI-1 activity at the low end. The purpose of this study was to investigate if patients with low PAI-1 activity have a lack of inflammatory response or a low insulin level.

DESIGN

Retrospective cohort study with internal controls.

SUBJECTS

Sixty-three patients referred for investigation of bleeding tendency and with low PAI-1 activity were compared with 118 patients with normal or high PAI-1 activity.

OUTCOME

Levels of C-peptide, proinsulin, high-sensitivity C-reactive protein (hs-CRP) and interleukin-6 (IL-6). Adjustments were made for body mass index (BMI), oral oestrogens and age. Low PAI-1 activity was defined as less than 1 U mL(-1).

RESULTS

Body mass index in the low normal range, oral oestrogens, young age and low C-peptide were significantly associated with low PAI-1 activity and there was a trend for association with IL-6 in univariable analysis. The effect of age disappeared after correction for oral oestrogens and the effect of C-peptide and IL-6 disappeared after further adjustments. Low BMI remained as the strongest predictor of low PAI-1 activity.

CONCLUSION

Patients with bleeding tendency and low PAI-1 activity have inflammatory and insulin profiles similar to those with normal or high PAI-1, whereas BMI seems to be the most important determinant.

Laboratory evidence of hyperfibrinolysis in association with low plasminogen activator inhibitor type 1 activity

Low activity of plasminogen activator inhibitor type 1 (PAI-1) has been associated with bleeding complications in surgery. We earlier reported a higher prevalence of low PAI-1 activity among patients with bleeding tendency as compared with normal control individuals. The present study evaluated whether low PAI-1 activity actually is associated with markers of increased fibrinolytic activity in plasma from patients with a history of bleeding. PAI-1 activity, plasmin-antiplasmin complex (PAP) and D-dimer were analyzed in plasma samples from 424 consecutive patients referred to the Coagulation Unit for investigation of bleeding symptoms. The median PAI-1 activity was 4.0 U/ml [interquartile range (IQR), 1-10 U/ml], the median PAP level was 1.59 mg/l (IQR, 1.40-1.91 mg/l) and the median D-dimer level was 71 microg/l (IQR, 46-111 microg/l). The median PAP concentration for patients with PAI-1 less than 1.0 U/ml was 1.73 mg/l (IQR, 1.53-2.30 mg/l), and that for PAI-1 of at least 1.0 U/ml was 1.54 mg/l (IQR, 1.36-1.83 mg/l) (P < 0.0001). There was also a significant difference between the PAP levels in patients with normal PAI-1 (1-15 U/ml) versus elevated PAI-1 (> 15 U/ml) (P = 0.024). The level of D-dimer did not correlate with PAI-1 activity. In conclusion, the activation of plasminogen measured as PAP was higher in patients with bleeding symptoms in combination with PAI-1 activity less than 1.0 U/ml than in those with PAI-1 activity of at least 1.0 U/ml. The coagulation activity under normal conditions, as measured by D-dimer, did not differ between the two patient subsets. The results support our previous definition of low PAI-1 as activity below 1.0 U/ml.

Low PAI-1 activity in relation to the risk for perioperative bleeding complications in transurethral resection of the prostate

INTRODUCTION

Low levels of plasminogen activator inhibitor type 1 (PAI-1) have been associated with increased risk for perioperative bleeding in some case reports. The aim of this study was to investigate prospectively whether low PAI-1 activity increases the risk for perioperative bleeding in patients undergoing transurethral resection of prostate, an organ with high fibrinolytic activity.

PATIENTS AND METHODS

62 patients with benign prostatic hyperplasia planned for transurethral resection were included. Blood samples for PAI-1 were taken together with other routine preoperative blood samples 1week before surgery but analyzed after the hospitalization. The intraoperative blood loss was determined by measuring the amount of hemoglobin in the irrigating fluid. The postoperative blood loss was estimated from calculations of hemoglobin mass (Hb mass), which is a product of hemoglobin concentration and blood volume. Hb mass was calculated before surgery and on the day of discharge, and was adjusted for intraoperative blood loss and transfused Hb mass. Bleeding complications were defined as re-operation due to bleeding, more than 40ml intraoperative bleeding/g resected prostatic tissue or postoperative blood loss corresponding to more than 100g of hemoglobin.

RESULTS

Bleeding complications were observed in 3 of 4 (75%) patients with low PAI-1 levels, defined as <1U/ml, and in 16 of 58 (28%) patients with PAI-1 levels >1U/ml (P=0.082). After adjustment for resection time, resected prostatic mass and systolic blood pressure this became borderline significant (odds ratio 11.8; 95% confidence interval 1.00-139; P=0.05).

CONCLUSION

Low PAI-1 activity may contribute to the risk of bleeding after transurethral resection of the prostate.

Uterine Artery Embolization for Control of Life-Threatening Hemorrhage at Menarche: Brief Report

Uncontrolled acute menorrhagia resulting in hemodynamic instability in the adolescent is uncommon. We report a case of life-threatening menorrhagia upon first menses in a 12-year-old girl who was successfully treated with uterine artery embolization after failure of standard gynecologic and medical measures. Testing eventually revealed a coagulopathy that resulted from decreased plasminogen activator inhibitor-1 activity in combination with an immature hypothalamic-pituitary-ovarian axis. Coagulation disorders are more common in patients presenting with severe menorrhagia upon menarche. Interventional radiologists should be aware of such coagulation abnormalities and the differences between adults and adolescents when contemplating uterine artery embolization for adolescent patients.

Endocrine regulation of menstruation

In women, endometrial morphology and function undergo characteristic changes every menstrual cycle. These changes are crucial for perpetuation of the species and are orchestrated to prepare the endometrium for implantation of a conceptus. In the absence of pregnancy, the human endometrium is sloughed off at menstruation over a period of a few days. Tissue repair, growth, angiogenesis, differentiation, and receptivity ensue to prepare the endometrium for implantation in the next cycle. Ovarian sex steroids through interaction with different cognate nuclear receptors regulate the expression of a cascade of local factors within the endometrium that act in an autocrine/paracrine and even intracrine manner. Such interactions initiate complex events within the endometrium that are crucial for implantation and, in the absence thereof, normal menstruation. A clearer understanding of regulation of normal endometrial function will provide an insight into causes of menstrual dysfunction such as menorrhagia (heavy menstrual bleeding) and dysmenorrhea (painful periods). The molecular pathways that precipitate these pathologies remain largely undefined. Future research efforts to provide greater insight into these pathways will lead to the development of novel drugs that would target identified aberrations in expression and/or of local uterine factors that are crucial for normal endometrial function.

Evaluation of low PAI-1 activity as a risk factor for hemorrhagic diathesis

BACKGROUND

Prospective studies of the epidemiology and clinical significance of low plasminogen activator inhibitor type 1 (PAI-1) activity are lacking.

OBJECTIVE

To evaluate the prevalence of low PAI-1 activity in patients with a bleeding tendency in comparison with a normal population.

METHODS

In 586 consecutive patients, referred because of bleeding symptoms, we added analyses of PAI-1 activity and tissue plasminogen activator complex with PAI-1 (t-PA-PAI-1) to the routine investigation, consisting of platelet count, bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen, factor VIII, von Willebrand factor activity, and antigen. Controls were 100 blood donors and 100 age- and sex-matched healthy individuals. The latter were also evaluated regarding the previous bleeding episodes. The bleeding history was classified as clinically significant or not, and the criteria were fulfilled in 75% of the patients and 18% of the healthy controls.

RESULTS

The routine laboratory investigation of the patients was negative in 57%. Low PAI-1 activity, defined as <1.0 U mL(-1), was found in 23% of the patients and in 13% and 10% of the blood donors and healthy controls, respectively (odds ratio and 95% CI, 2.04; 1.11-3.77 and 2.75; 1.39-5.42, respectively). The difference remained statistically significant after the adjustment for body mass index, use of estrogens, sex and age (odds ratio for patients vs. healthy controls 3.23; 95% CI, 1.22-8.56, P = 0.019). The distribution of the 4G/5G genotypes in the patients was not different from that of two control populations. No specific symptom predicted for low PAI-1, which did not aggravate the clinical picture in association with the other hemostatic defects. Low tPA-PAI-1 was not associated with the increased bleeding tendency.

CONCLUSION

Low PAI-1 activity is common in patients with a bleeding diathesis, but it is a risk factor of minor clinical importance and not associated with specific bleeding manifestations.

Massive subhyaloidal hemorrhage associated with severe PAI-1 deficiency

PURPOSE

To report an association between spontaneous subhyaloidal hemorrhage and severe plasminogen activator inhibitor-1 (PAI-1) deficiency.

METHODS

Case report.

RESULTS

A 29-year-old woman presented with sudden, painless visual loss to hand motion in her right eye. Ophthalmoscopy showed a massive subhyaloidal hemorrhage. The patients' medical history was negative for cardiovascular risk factors, trauma, infections or bleeding complications. Further investigation into possible causes revealed hyperfibrinolysis secondary to severe PAI-1 deficiency. The non-clearing subhyaloidal hemorrhage was successfully treated by pars plana vitrectomy, and her visual acuity improved to 20/20.

CONCLUSION

When ordering laboratory tests in patients with spontaneous subhyaloidal hemorrhage to rule out fibrinolytic disorders, severe PAI-1 deficiency should be considered in the differential diagnosis. Selective screening may be helpful in identifying ophthalmologic patients with hyperfibrinolysis, especially in young individuals with subhyaloidal hemorrhages in the absence of other recognized risk factors.