The systemic nature of the antiphospholipid syndrome

Unexplained huge liver infarction presenting as a tumor with bleeding: A case report

BACKGROUND

Liver infarction is a rare necrotic lesion due to the dual blood supply consisting of the hepatic artery and portal vein. The absence of specific clinical manifestations and imaging appearances usually leads to misdiagnosis and poor prognosis. Thus, the precise diagnosis of liver infarction always requires imaging studies, serum studies, and possible liver biopsy.

CASE SUMMARY

We report a case of 31-year-old man who developed a huge liver infarction. Persistent right upper abdominal pain and intermittent fever were the main symptoms in this patient. Computed tomography revealed a huge irregular lesion with a maximum diameter of 12.7 cm in the right lobe of the liver. Three-dimensional reconstruction was performed and no significant interruption of the main hepatic vessels was observed. The lesion was initially considered to be a malignant tumor with internal bleeding. Laparoscopic right hepatectomy was performed, and pathology indicated a rare liver infarction. The patient recovered well and was discharged on postoperative day 21. No fever or abnormal liver function were reported in the subsequent 6 mo.

CONCLUSION

In patients with a huge liver infarction, early surgical intervention may be beneficial.

Selective adsorption of antiphospholipid and anti-dsDNA autoantibodies on histidine based pseudobioaffinity adsorbent from sera of patients with systemic lupus erythematosus (SLE)

Systemic lupus erythematosus (SLE) is an autoimmune diseases characterized by the presence of antiphospholipid and anti-dsDNA autoantibodies in the sera of patients. These autoantibodies and their subclasses have received increasing attention by medical community due to their association with recurrent venous thrombosis, fetal loss and thrombocytopenia. In particular, attention has been paid to IgG subclasses in SLE. The biological and functional properties together with the subclass distribution might therefore influence the course of SLE. The separation and elimination of these autoantibodies from sera of patients can be effective in clinical therapy. In the present study, histidine based pseudobioaffinity adsorbents have been used for the selective adsorption and separation of anti-double stranded DNA (anti-dsDNA), anticardiolipin (aCL) and anti-β2-glycoprotein-I (anti-β2-GPI) antibodies from sera of patients with SLE. For this purpose histidine acting as a pseudobiospecific ligand has been coupled to bisoxirane activated sepharose CL-6B for the adsorption and separation of these autoantibodies. The removal of autoantibodies was carried out under gentle adsorption and elution chromatographic conditions at pH values 7.0 and 8.0. Autoantibodies isotypes and subclasses distribution in the separated fractions were studied by enzyme-linked immune-sorbent assay. The obtained results showed that the separated anticardiolipin and anti-β2-glycoprotein-I autoantibodies belong to IgG1, IgG2 and IgG3subclasses, while those of anti-dsDNA belong to IgM isotype and were shown to have a DNA hydrolyzing activity that hydrolyzes plasmid DNA. The results also indicate a total IgM and IgG recovery superior to 90% of the fraction loaded at pH 7.4 and pH 8.0 respectively.

Major adverse cardiovascular events and mortality in systemic lupus erythematosus patients after successful delivery: a population-based study

BACKGROUND

Limited data exist regarding the incidence rate and hazard ratios (HRs) of major adverse cardiovascular events and mortality in the successful-delivery women with or without systemic lupus erythematosus.

METHODS

A retrospective, population-based cohort study was performed on 1,132,089 parturients from 1999 to 2003. The Kaplan-Meier method and the log-rank test were used to examine the effect of systemic lupus erythematosus on the incidence of major adverse cardiovascular events and mortality. Cox-proportional hazard regression modeling was used to determine the adjusted HRs of systemic lupus erythematosus on the risk of major adverse cardiovascular events and mortality among successful-delivery women.

RESULTS

Systemic lupus erythematosus group has the highest risk for major adverse cardiovascular events and mortality. The incidence rate of major adverse cardiovascular events and all-causes mortality among lupus women was 194.67 and 438.82 per 100,000 patients per year, respectively. Lupus women had higher incidence rates of major adverse cardiovascular events, including myocardial infarction, (HR, 54.43; confidence interval [CI], 16.04-184.78; P < 0.0001), heart failure (HR, 11.10; CI, 2.71-45.52; P < 0.0001), percutaneous coronary intervention (HR, 228.32; CI, 43.34-1203.00; P < 0.0001), stroke (HR, 8.02; CI, 3.79-16.99; P < 0.0001) and maternal death (HR, 11.68; CI, 7.97-17.10; P < 0.0001).

CONCLUSIONS

Although major adverse cardiovascular events and mortality are rare events in women of reproductive age, the incidence rates have increased approximately 10-fold among lupus women with successful delivery. Clinicians should note the possibility of persisting major adverse cardiovascular events and death in young women with lupus and successful delivery.

Atherosclerosis in Asian Indians with systemic lupus erythematosus

OBJECTIVES

Atherosclerosis has emerged as an important late complication of systemic lupus erythematosus (SLE). Asian Indians, as an ethnic group, are known to be metabolically predisposed to development of early atherosclerosis. No data on this aspect of SLE are available from Asia. This study was undertaken to find the frequency of atherosclerosis in Indian lupus patients and the factors affecting such an occurrence.

METHODS

Carotid artery intimo-medial thickness (IMT) and plaque were used as markers of atherosclerosis. High-resolution B-mode ultrasonography was used to compare carotid IMT and plaque in 50 patients with SLE and 50 age- and sex-matched healthy controls.

RESULTS

Patients with lupus (age 31.6+/-10.05, median 30.5 years; disease duration 52.3+/-36.7, median 46 months) exhibited a significantly greater IMT than controls (0.417+/-0.07 vs. 0.362+/-00.07 mm; p = 0.003). Carotid plaques were seen in seven (14%) cases. None of the control population had plaques (p = 0.006). On bivariate analysis, the IMT was significantly affected by age, systolic blood pressure (SBP), disease duration and menopausal status. On multivariate analysis, the only factor significantly affecting IMT was SBP. The Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) score was the sole factor found to significantly affect the occurrence of plaque.

CONCLUSIONS

Asian Indian lupus patients in our study, despite being relatively young and with shorter disease duration, exhibited premature atherosclerosis in the form of significantly thicker intimo-media and plaque. The factors found to affect accelerated atherosclerosis in our cohort were age, SBP, disease duration, postmenopausal status and the SLICC/ACR score.

Pulmonary dysfunction in systemic lupus erythematosus and anti‐phospholipid syndrome patients

OBJECTIVE

To assess and compare parameters of pulmonary function in systemic lupus erythematosus (SLE) and anti-phospholipid syndrome (APS) patients.

METHODS

Consecutive patients (n = 74) who were free of respiratory symptoms were divided into four groups: 1) SLE (n = 23); 2) SLE with anti-phospholipid antibodies (aPL) (n = 18); 3) SLE with APS (n = 20); and 4) primary APS (PAPS) (n = 13). Pulmonary function testing, single breath diffusion capacity of carbon monoxide (DLCO/SB) and echocardiography studies were performed. Induced sputum cytology was analysed.

RESULTS

Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), and DLCO were significantly reduced in SLE compared to PAPS patients (p = 0.039; p = 0.017; p = 0.029, respectively). Elevated pulmonary arterial pressure was observed in two patients with SLE and aPL and in two with SLE and APS. Lymphocyte and eosinophil counts in induced sputum showed no significant differences; however, a trend towards lower CD4 counts in SLE vs. PAPS was noted (p = 0.086), while in patients with both SLE and APS, a low CD4/CD8 ratio was seen. Patients with APS were older than patients without APS (47.12+/-14.86 vs. 34.29+/-12.6, p = 0.0001), while SLE patients were younger than PAPS patients (38.19+/-14.68 vs. 48.53+/-13.97, p = 0.023).

CONCLUSION

Abnormal pulmonary functions tests were detected frequently in asymptomatic patients with SLE or PAPS. Although SLE patients were younger, pulmonary function was significantly more impaired in SLE as compared to PAPS patients.

Genotype Ser413/Ser ofPAI‐2 polymorphism Ser413/Cys is associated with anti‐phospholipid syndrome and systemic lupus erythematosus in a familial case: comparison with healthy controls

BACKGROUND

We describe a family with a 7-year-old proband case diagnosed with systemic lupus erythematosus (SLE) plus secondary anti-phospholipid syndrome (APS) as well as two affected paternal aunts. We compared the frequency of these polymorphisms with healthy controls.

OBJECTIVES

To evaluate the mode of inheritance in this familial case of APS and SLE and the possible association of plasminogen activator inhibitor-1 (PAI-1) -675 4G/5G and PAI-2 Ser(413)/Cys polymorphisms. To compare the genotype frequency of these polymorphisms with the results found in a Mexican Mestizo population.

METHODS

PAI-1 -675 4G/5G and PAI-2 Ser(413)/Cys were determined by the polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) technique using Bsl I and Mwo I on four generations of the family studied. PAI-2 Ser(413)/Cys polymorphism was also determined in 50 healthy individuals of Mexican Mestizo origin.

RESULTS

The family pedigree demonstrated that this family did not follow a Mendelian inheritance pattern. When the PAI-2 Ser(413)/Cys polymorphism was examined, we found that 60% (3/5) of the relatives homozygous to Ser(413)/Ser were affected with SLE and/or APS (p = 0.027). The proband case was 4G/5G genotype for the PAI-1 -675 4G/5G polymorphism. No differences between healthy controls of the Mexican Mestizo population and the family studied for the PAI-2 Ser(413)/Cys polymorphism or PAI-1 -675 4G/5G polymorphisms were found.

CONCLUSIONS

Our data indicate that this family did not follow the Mendelian inheritance pattern. The Ser(413)/Ser genotype demonstrated in 60% of the affected members (3/5) of this family might increase the risk for autoimmune syndromes such as APS or SLE.

Prevalence and clinical correlates of anti‐phospholipid antibodies in South Africans with systemic lupus erythematosus

OBJECTIVE

To determine the prevalence and clinical correlates of anti-phospholipid antibodies (aPL), including anti-cardiolipin antibodies (aCL), lupus anti-coagulant (LA), anti-beta2-glycoprotein 1 (abeta2GP1), and anti-prothrombin (aPT) antibodies, in Black South African patients with systemic lupus erythematosus (SLE).

METHODS

A cross-sectional study of 100 SLE patients in whom clinical characteristics, including features of the anti-phospholipid syndrome (APS), disease activity, and damage were documented, and sera tested for aCL, abeta2GP, and aPT of all isotypes, and LA.

RESULTS

Positive aCL, abeta2GPI, aPT, and LA were found in 53, 84, 20, and 2 patients, respectively. Immunoglobulin (Ig)A aCL and IgG abeta2GPI were the commonest aCL (49.1%) and abeta2GPI (47%) isotypes, respectively. IgA abeta2GPI were associated with both a history of thrombosis alone (p<0.05) and a history of any clinical feature, thrombosis, and/or spontaneous abortion of the APS (p<0.05); IgA aCL were associated with a history of any clinical APS event (p<0.05); and abeta2GPI of any isotype were associated with a history of arthritis (p<0.001).

CONCLUSION

Our findings provide further evidence that screening for abeta2GPI and IgA aCL isotypes may improve the risk assessment for APS in SLE patients of African extraction. Further prospective studies are warranted to determine the clinical utility of these tests and to elucidate the genetic basis for the increased IgA aPL response in SLE patients of African extraction.

Spontaneous retroperitoneal bleeding from renal microaneurysms and pancreatic pseudocyst in a patient with systemic lupus erythematosus

Visceral vasculitis and pancreatic pseudocyst are rare manifestations of systemic lupus erythematosus (SLE). We describe a patient with SLE who presented with spontaneous bilateral perinephric and retroperitoneal haematoma secondary to polyarteritis nodosa (PAN)-like vasculitis of the renal arteries, which subsequently evolved into systemic vasculitis with pancreatic pseudocyst formation.

APS--more systemic disease than SLE

The antiphospholipid syndrome is a systemic autoimmune disease that can have serious consequences for patients. Importantly, there is a wide range of clinical presentations. In this issue we have attempted to provide an overview of these features and place it in the context of autoimmunity.

Thrombosis risk in systemic lupus erythematosus: the role of thrombophilic risk factors

OBJECTIVES

Thromboembolic episodes are frequent manifestations of systemic lupus erythematosus (SLE). Although the presence of anti-phospholipid antibodies (aPL) is known to contribute to thromboembolism (TE), the relative contribution of other TE risk factors is unknown. The aim of this study was to determine the prevalence of TE in a Caucasian SLE population, to identify the risk factors of highest importance, and to assess the clinical value of thrombophilia screening among SLE patients.

METHODS

Samples from 105 patients were analysed with a screen including aPL, activated protein C resistance, factor V Leiden (FVL) and prothrombin G20210A mutations; protein C, protein S and antithrombin activity; factor VIII (FVIII) and von Willebrand factor (vWF), and homocysteine (Hcy) levels.

RESULTS

The annual incidence of arterial and venous TE events in our SLE population was 5.4 and 12.4 per 1000, respectively. The highest risk of thrombosis was carried by the simultaneous presence of lupus anticoagulant (LA) and anti-cardiolipin (aCL) [relative risk (RR) = 4.03, 95% confidence interval (CI) 2.06-7.86] or anti-beta2-glycoprotein I antibodies (abeta2-GPI) (RR = 5.10, 95% CI 2.58-10.1). Positivity for the individual aPL tests all carried an elevated TE risk. The presence of other risk factors seemed to be of less importance.

CONCLUSIONS

In SLE patients, the presence of aPL is a more significant risk factor for the development of thrombosis than the known inherited deficiencies. Based on these data, routine screening for additional hereditary risk factors seems to be unwarranted.

Autoantibodies to plasminogen and tissue plasminogen activator in women with recurrent pregnancy loss

Reduced fibrinolytic activity has been described in primary anti-phospholipid syndrome (PAPS), and may be responsible for thrombotic events. Antibodies to tissue type plasminogen activator (t-PA) or plasminogen (PLG) might contribute to the hypofibrinolytic state in autoimmune diseases, but the clinical significance of these antibodies is still unclear in recurrent pregnancy loss (RPL). The aim of this study is to evaluate the prevalence and clinical significance of anti-PLG and anti-t-PA antibodies in 87 patients with a history of RPL: 54 women with well-defined PAPS (mean age 32.5 years; range 26-38) and 33 women with unexplained RPL (mean age 30 years; range 24-39). IgG anti-PLG antibodies were found in 20 and four patients from the group with RPL/PAPS and unexplained RPL, respectively; IgG anti-t-PA antibodies were found in 11 and two patients from the above two groups, respectively. IgG anti-PLG antibodies were associated with the high risk of RPL (OR 7.2, P = 0.004), especially with RPL/PAPS (OR 11.2, P < 0.001) evaluated by Fisher's exact test, while IgG anti-t-PA were associated with RPL/PAPS (OR 10.0, P = 0.01) but not with RPL (OR 6.8, P = 0.06). A significant inhibition of exogenous fibrinolysis was observed by IgG fractions from patients with anti-PLG or anti-t-PA antibodies on microplates and on the human umbilical vein endothelial cells, compared with those from healthy controls. The prevalence of IgG anti-PLG antibodies was high in RPL patients, especially in RPL/PAPS, while the prevalence of IgG anti-t-PA antibodies was high in RPL/PAPS but not in RPL, and some of them might inhibit fibrinolysis in patients.

Sudden sensorineural hearing loss in a patient with primary antiphospholipid syndrome

Objective:

Despite multiple systemic manifestations, sudden sensorineural hearing loss in a patient with antiphospholipid syndrome is rarely reported.

Patient:

A 46-year-old man with primary antiphospholipid syndrome had a sudden onset of hearing loss and tinnitus in the right ear in December 2005, because he discontinued use of warfarin and acetylsalicylic acid for a few days.

Results:

Audiometry revealed saucer-type sensorineural hearing loss with a pure tone average of 73 dB in the right ear, and flat-type hearing loss with a pure tone average of 25 dB in the left ear. Electronystagmography displayed multiple central signs and bilateral canal paresis, while a vestibular evoked myogenic potential test revealed bilateral delayed responses. After admission, the patient was re-treated with warfarin and acetylsalicylic acid. Follow-up audiometry showed recovery of right-sided hearing, with a pure tone average of 12 dB, three days after presentation.

Conclusion:

Consensus exists on the effectiveness of anticoagulant agents in aiding a favourable outcome of sudden sensorineural hearing loss in patients with antiphospholipid syndrome.

Stenosis in antiphospholipid syndrome: a new finding with clinical implications

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by a variety of clinical manifestations. Recent studies suggest arterial stenosis is involved in APS. Furthermore, arterial stenosis may be a relevant and treatable cause for hypertension, renal, CNS and gastrointestinal manifestations of APS. Our objective was to overview the published data regarding arterial stenosis in APS--the clinical presentation, diagnosis, suggested therapies and the possible mechanisms. We searched PUBMED (1951-2006) reference lists for the role of arterial stenosis in APS. APS patients might present with arterial stenosis. Its recognition has important diagnostic and therapeutic implications. Articles suggest that anticoagulation treatment with INR above three may reverse the artery stenosis and achieve subsequent clinical improvement. Currently, there are no specific guidelines for the management of APS patients with arterial stenosis. The exact mechanism of arterial stenosis in APS patients remains unclear.

Liver infarction in a woman with systemic lupus erythematosus and secondary anti-phospholipid and HELLP syndrome

We report a 39-year-old primigravida, a case of systemic lupus erythematosus (SLE) and secondary anti-phospholipid syndrome (APS) with a smooth antenatal course who delivered by caesarean for non-reassuring foetal heart rate. On day 2 postoperatively, she developed a sudden severe colicky upper abdominal pain with tachypnoea, dyspnoea, and tachycardia, and blood pressure (BP) reaching 150/95 mmHg. Computed tomography of the abdomen revealed lesions consistent with liver infarction. She developed haemolytic anaemia, elevated liver enzymes, and low platelets (HELLP syndrome); heparin and methylprednisolone were started. On day 3, BP normalized, respiratory symptoms improved but abdominal symptoms persisted. Methylprednisolone was increased to 80 mg/day on day 8 when she had significant clinical response and was discharged on day 16. This case emphasizes that a morbid clinical course including liver infarction should be anticipated in patients with SLE and APS complicated with HELLP syndrome.

Factores relacionados con el riesgo de trombosis en pacientes con lupus y positividad para anticuerpos antifosfolipídicos

BACKGROUND AND OBJECTIVE

Antiphospholipid antibodies (aPL) are frequently associated with eritematosus systemic lupus (SLE) and increases the risk of thrombosis. The aim of the study was to analize risk factors of thrombosis and its temporal profile in subjects with SLE.

PATIENTS AND METHOD

One hundred and two SLE patients -mean age: 37.5 years (range: 8-85); 90 women; mean of follow-up: 72 months (range: 9-324); 41 (40.2%) with aPL positive- were included in the study. Actuarial Kaplan-Meier curves were used to assess the thrombosis risk and Cox proportional hazard model was used to evaluate factors associated with the risk.

RESULTS

13 thrombotic events occurred in the group with aPL positive (mean of follow up: 83.5 months) and 5 events in aPL negative group (mean of follow up: 72 months). The event-rates were 3.93 and 0.96/100 patients/year for each group, respectively. Survival curves showed a significantly higher risk of thrombotic events in the patients with positive aPL as compared to the aPL negative group, and the risk still present throughout the observational time. Activated partial thromboplastine time up to 37 s was significantly associated with thrombosis risk (p = 0.003). Furthermore, positivity of lupus anticoagulant and proteinuria > 2.5 g/day tended to increase thrombotic risk, although they did not achieve statistical significance.

CONCLUSIONS

In patients with SLE and aPL, risk of first thrombosis remains over the years, and a large activated partial thromboplastine time was the most important risk factor.

Coagulation Defects

The present understanding of the coagulation process emphasizes the final common pathway and the proteolytic systems that result in the degradation of formed clots and the prevention of unwanted clot formations, as well as a variety of defense systems that include tissue repair, autoimmune processes, arteriosclerosis, tumor growth, the spread of metastases, and defense systems against micro-organisms. This article discusses diagnosis and management of some of the most common bleeding disorders. The goals are to provide a simple guide on how best to manage patients afflicted with congenital or acquired clotting abnormalities during the perioperative period, present a brief overview of the methods of testing and monitoring the coagulation defects, and discuss the appropriate pharmacologic or blood component therapies for each disease.

antiphospholipid antibodies syndrome associated with hyperhomocysteinemia related to MTHFR Gene C677T and A1298C heterozygous mutations in a young man with idiopathic hypoparathyroidism (DiGeorge syndrome)

CONTEXT

Antiphospholipid syndrome (APS, or Hughes' syndrome) is a systemic autoimmune disorder characterized by antiphospholipid antibody positivity, which may lead to arterial and/or venous thrombosis. Hyperhomocysteinemia (HHcy), variously associated with 5,10-methylene tetrahydrofolate reductase (MTHFR) gene point mutations, is also implicated in thromboembolic events. The association of APS and HHcy has already been described but has never been reported in patients with DiGeorge syndrome (DGS), the most common contiguous-gene deletion syndrome (22q11.2) in humans, whose phenotype conversely includes bleeding disorders.

DATA ACQUISITION

In this report, we present the case of a 19-yr-old patient with a past medical history of learning disability and obesity affected with idiopathic hypoparathyroidism, metabolic syndrome, and diffuse vasculitis disorders. He was referred to our endocrinology clinic for the management of severe hypocalcemia. At the time of presentation he had been taking antiepileptic drugs for 2 wk and displayed facial dysmorphism (short neck, micrognathia, a small mouth, hypoplastic nasal alae, eye hypertelorism, and low-set simple ears). DGS was suspected and confirmed by both fluorescence in situ hybridization analysis and single nucleotide polymorphism-array analysis, which revealed contiguous gene microdeletion of the chromosome 22q11.2 in the minimal DiGeorge critical region, specifically at the gene locus D22S75 (N25).

CONCLUSIONS

APS, revealed by anti-beta-2-glycoprotein and anti-prothrombin antibodies positivity, and moderate HHcy related to heterozygous C677T and A1298C point mutations of the MTHFR gene were identified as a possible cause of thrombotic disorder responsible for the widespread presence of cutaneous and cerebral lesions.

Arterial compliance: is it reduced in antiphospholipid syndrome?

To assess vascular compliance in patients with antiphospholipid syndrome (APS), or antiphospholipid antibodies (aPLs) positivity in comparison to healthy people and diabetes mellitus patients. Twenty-five patients with APS or aPLs, 33 healthy people (HP), 28 patients with diabetes mellitus (DM) underwent pulse wave analysis. Data calculated included the small artery elasticity (SAE), large artery elasticity (LAE) and systemic vascular resistance (SVR). Statistical analysis was performed as appropriate. The patient group was divided into two subgroups: APS-1 with warfarin treatment, and APS-2 without warfarin treatment. All patients and healthy subjects were matched by gender, body mass index and lipid profiles. Patients in APS-1 group were significantly younger in comparison to three other groups. After the adjustment for age, we found that SAE in APS-1 group did not differ from SAE in the HP group (6.4+/-1.8 ml/mmHg x 100 and 5.54+/-3.4 ml/mmHg x 100, respectively, P>0.05). In contrast, SAE in the group APS-2 was significantly lower (3.41+/-1.2 ml/mmHg x 100) than in the APS-1 and was almost equal to SAE in the DM group (4.2+/-2.37 ml/mmHg x 100). The SAE in the APS-2, DM and HP groups was inversely correlated with age, whereas in the APS-1 group we did not find such correlation. This pilot study showed abnormal small vascular elasticity in the patients with positive aPL, relative to the healthy subjects. The APS patients, treated with warfarin had the normal vascular function. This data support the hypothesis that APS may be associated with diffuse changes in the arterial wall, and may be a risk factor for atherosclerotic disease.

Síndrome antifosfolípide

Condição adquirida, sistêmica, caracterizada por tromboses recorrentes no sistema arterial, venoso ou ambos, a síndrome antifosfolípide pode ser primária ou secundária, esta última mais associada ao lúpus eritematoso sistêmico e menos freqüentemente a infecções, fármacos e outras doenças. São marcadores sorológicos da síndrome antifosfolípide os anticorpos antifosfolípides anticoagulante lúpico e anticardiolipina. O critério diagnóstico primário inclui trombose arterial ou venosa e morte fetal recorrente. Cerca de 41% dos pacientes apresentam lesões cutâneas como primeiro sinal da síndrome, que também pode provocar livedo reticular, ulcerações cutâneas, vasculite livedóide, entre outras manifestações. Seu controle consiste principalmente no tratamento e profilaxia da trombose com anticoagulantes e antiagregantes plaquetários.