Current debates in antiphospholipid syndrome: the acquired antibody-mediated thrombophilia

Even low levels of anticardiolipin antibodies are associated with pregnancy-related complications: A monocentric cohort study

INTRODUCTION

Moderate and high levels of anticardiolipin antibodies (aCL), especially in the setting of the antiphospholipid syndrome, are associated with adverse obstetric outcomes. However, the clinical relevance of low aCL levels (<40 MPL/GPL units) is still a matter of debate. The aim of the study was to evaluate obstetric outcomes in pregnancies with low immunoglobulin M (IgM) and/or immunoglobulin G (IgG) aCL positivity. The association between low aCL positivity and maternal baseline characteristics was also studied.

MATERIAL AND METHODS

The retrospective monocentric cohort study of prospectively collected data involved a total 3047 singleton pregnancies that underwent the first-trimester screening involving an aCL test and delivered on site. Obstetric outcomes were compared between the low-titer aCL group (IgM ≥7 MPL units and <40 MPL units and/or IgG ≥10 GPL units and <40 GPL units) and the aCL negative group (IgM <7 MPL units and IgG <10 GPL units, reference group). In addition, obstetric outcomes were evaluated with regard to the antibody isotype: IgM-positive group (IgM <40 MPL units, IgG negative) and IgG-positive group (IgG <40 GPL units, IgM negative or <40 MPL units).

RESULTS

Overall, the occurrence of pregnancy-related complications was significantly higher (27.91% vs. 19.32%, p = 0.034) in the low-titer aCL group. Concerning the antibody isotype, a higher rate of pregnancy-related complications was observed in the IgG-positive group (54.55% vs. 19.32%, p = 0.001), but not in the IgM-positive group (22.43% vs. 19.32%, p = 0.454). The stillbirth rate did not reach statistical significance. Low-titer aCL pregnancies were more frequently of advanced maternal age (p < 0.001), suffered from autoimmune diseases (p < 0.001), chronic hypertension (p = 0.040), and hereditary thrombophilia (p = 0.040). In addition, they had more often a positive history of stillbirth (p < 0.001), underwent conception via assisted reproductive technologies (p < 0.001), were administered low-dose aspirin (p < 0.001), low-molecular-weight heparin (p = 0.018) and immunomodulatory drugs (p < 0.001), and delivered earlier (p = 0.018).

CONCLUSIONS

Even low aCL levels are associated with a higher incidence of pregnancy-related complications, but only in the case of IgG antibody isotype presence. Screening for aCL in the first trimester has some prognostic value, but further studies are needed to determine whether its potential implementation into routine clinical practice would improve antenatal care.

Direct oral anticoagulants vs. vitamin K antagonists in patients with antiphospholipid syndrome: a systematic review and meta-analysis

Optimal treatment regimen for patients with antiphospholipid syndrome (APS) remain unclear. Therefore, the authors sought to compare the outcomes of vitamin K antagonists (VKAs) vs. direct oral anticoagulants (DOACs) in patients with APS.

METHODS

MEDLINE, Embase, and Cochrane Central databases were searched for randomized controlled trials comparing efficacy and safety of VKAs and DOACs inhibitors in patients with APS. Recurrent thrombosis, all-cause mortality, stroke, adverse reactions, and bleeding were among outcomes of interest. Mantel-Haenszel weighted random-effects model was used to calculate relative risks (RRs) with 95% CIs.

RESULTS

The analysis included 625 patients from four randomized controlled trials and one post hoc analysis. Meta-analysis showed statistically non-significant difference between DOACs inhibitors and VKAs in the recurrent thrombosis risk (arterial or venous) [RR 2.77 (95%, CI 0.79, 9.65); P=0.11, I2=50%]. Consistent results were revealed among patients with the previous history of arterial thrombosis [RR 2.76 (95% CI 0.93, 8.16); P=0.75, I2=0%], venous thrombosis [RR 1.71 (95% CI 0.60, 4.84); P=0.31, I2=15%] and patients who were triple antiphospholipid positive [RR 4.12 (95% CI 0.46, 37.10); P=0.21, I2=58%]. DOACs inhibitors were significantly associated with increased risk of stroke [RR 8.51 (95% CI 2.35, 3.82); P=0.47, I2=0%].

CONCLUSION

DOACs exhibited increased risk of stroke among patients with APS. In addition, although not significant, the higher RRs among patients on DOACs may indicate higher risk of thrombotic events associated with DOACs.

Antibiotic-free vaginal microbiota transplant with donor engraftment, dysbiosis resolution and live birth after recurrent pregnancy loss: a proof of concept case study

Background

Vaginal dysbiosis covers imbalances in the vaginal microbiota, defined by altered composition of bacteria, viruses, and fungi and is associated with euploid pregnancy losses, premature birth, infertility, or bacterial vaginosis. A large proportion of women who have vaginal dysbiosis do not experience any symptoms. Antibiotics are the traditional treatment, recently combined with local probiotics in some cases. Vaginal Microbiota Transplantation (VMT) with eubiotic vaginal bacterial microbiota after antibiotic eradication of pathogens has successfully been performed in a case study with five patients, but no VMT has been performed without the use of antibiotics.

Methods

This is a proof of concept case study. The patient was found to have vaginal dysbiosis at the RPL clinic at Copenhagen University Hospital Hvidovre, Denmark on the 23rd of June 2021. She was offered and accepted to receive experimental treatment in the form of a VMT as a compassionate use case. VMT is the transfer of cervicovaginal secretions (CVS) from a healthy donor with a Lactobacillus-dominant vaginal microbiome to a recipient with a dysbiotic vaginal microbiome. CVS is a mixture of e.g., mucus, bacteria, metabolites present in the vaginal canal. Potential donors were thoroughly screened for the absence of STIs, and the most suitable donor sample for the specific patient in this study was determined via an in vitro microbiome competition assay.

Findings

A 30-year-old patient with one livebirth and a complicated pregnancy history of two stillbirths and 1 s trimester pregnancy loss in gestational weeks 27 (2019), 17 (2020) and 23 (2020) respectively with complaints of vaginal irritation and discharge that had aggravated in all her pregnancies. Her vaginal microbiome composition showed a 90% dominance of Gardnerella spp. After one VMT there was a complete shift in microbiome composition to 81.2% L. crispatus and 9% L. jensenii with a concurrent resolvement of vaginal symptoms. Single nucleotide polymorphism-analysis confirmed her microbiome to be of donor origin and it remain stable now 1.5 years after the VMT. Five months after the VMT she became pregnant and has successfully delivered a healthy baby at term.

Interpretation

Here we report a successful VMT with confirmed donor strain engraftment followed by a successful pregnancy and delivery after a series of late pregnancy losses/stillbirths. Findings suggest that VMT is a potential treatment for severe vaginal dysbiosis. Further, larger studies are required.

Funding

The study was partially funded (i.e., analysis costs) by Freya Biosciences Aps, Fruebjergvej, 2100 Copenhagen, Denmark.

Immune Thrombocytopenia Could be an Independent Clinical Phenotype of Antiphospholipid Syndrome: A Prospective Cohort Study

BACKGROUND

Patients with persistent positive antiphospholipid antibodies (aPLs) and immune thrombocytopenia (ITP) hardly develop thrombosis but share many similar characteristics with antiphospholipid syndrome (APS).

METHODS

This is a prospective cohort study consecutively enrolling thrombocytopenic patients with continuous positive aPLs. Patients developing thrombotic events are classified as the APS group. Then we compare the clinical characteristics and prognosis between aPLs carriers and patients with APS.

RESULTS

This cohort included 47 thrombocytopenic patients with continuous positive aPLs and 55 with diagnosed primary APS. The proportion of smoking and hypertension are higher in the APS group (p = 0.03, 0.04, 0.03, respectively). The platelet count of aPLs carriers at admission was lower than APS patients [26 × 10⁹/l (9 × 10⁹/l, 46 × 10⁹/l) vs. 64 × 10⁹/l (24 × 10⁹/l, 89 × 10⁹/l), p = 0.0002]. Triple aPLs positivity is more common in primary APS patients with thrombocytopenia [24 (51.1%) vs. 40 (72.7%), p = 0.04]. Regarding the treatment response, the complete response (CR) rate is similar between aPLs carriers and primary APS patients with thrombocytopenia (p = 0.2). Nonetheless, the proportion of response, no response, and relapse differed significantly between the two groups [13 (27.7%) vs. 4 (7.3%), p < 0.0001; 5 (10.6%) vs. 8 (14.5%), p < 0.0001; 5 (10.6%) vs. 8 (14.5%), p < 0.0001, respectively]. In Kaplan-Meier analysis, primary APS patients had significantly more thrombotic events than aPLs carriers (p = 0.0006).

CONCLUSIONS

In the absence of other high-risk factors for thrombosis, thrombocytopenia could be an independent and long-lasting clinical phenotype of APS.

Long Term Follow up of Patients With Primary Obstetric Antiphospholipid Syndrome

Introduction: Primary obstetric antiphospholipid syndrome (OAPS) is defined by specific morbidities and/or losses of pregnancy in the presence of persistent antiphospholipid antibodies (aPL). This variant of APS is usually treated during pregnancy and the post-partum period. Data on occurrence of thrombotic event during long term follow-up of OAPS patients is limited. Methods: A multi-centre retrospectively cohort of female patients with primary APS (pAPS) was assembled during 2004-2019. Patients were grouped according to disease presentation as pure OAPS or thrombotic APS (tAPS) for those presenting with thrombosis. Clinical and serological data were compared between groups. Results: Of 219 pAPS female patients 67 (30.6%) were diagnosed with OAPS and 152 (69.4%) with tAPS. During >10 years of follow-up 24/67 (35.8%) OAPS and 71/152 (50%) tAPS suffered a new thrombotic event (p = 0.06), while obstetric morbidity was more likely in the OAPS group (31.3 vs. 10.5%, p < 0.001) respectively. Among patients with OAPS at presentation heart valve disease and the presence of ANA were related to thrombosis following diagnosis (25 vs. 4.7%, p = 0.02; and 45.8 vs. 20.8%, p = 0.04 respectively). Conclusion: Thrombotic event following diagnosis were common among female patients with pAPS regardless of disease presentation. Heart valve disease and ANA positivity may be risk factors for thrombosis during follow-up of patients presenting with pure OAPS.

Osteonecrosis in Primary Antiphospholipid Syndrome is Associated with Previous Glucocorticoid Use and Thrombocytopenia

Introduction

The aim of this study was to investigate the frequency of avascular necrosis (AVN) and its associations with clinical and laboratory parameters in patients with primary antiphospholipid antibody syndrome (pAPS).

Methods

This was a cross-sectional study of 66 patients with pAPS who fulfilled the Sidney criteria for APS. Epidemiological and clinical data, and data on antiphospholipid antibodies were collected. Diagnosis of AVN was based on studies of magnetic resonance (MRI) images of affected bones.

Results

AVN was found in three of the 66 (4.5%) enrolled patients. Comparison of patients with pAPS with and without AVN showed that demographic data, comorbidities, and antiphospholipid antibodies profile were similar in both groups. Compared to patients without AVN, those with AVN had thrombocytopenia more frequently (66.7 vs. 7.9%) and used more glucocorticoids (100 vs. 35%).

Conclusion

AVN is rare in patients with pAPS and may be associated with thrombocytopenia and previous glucocorticoid use.

Cardiovascular Disease in Antiphospholipid Syndrome

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Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by venous, arterial or microvascular thrombosis or obstetric events in the presence of persistently positive antiphospholipid antibodies and constitutes a major cause of cardiovascular events in young people. Τhis review highlights the pathophysiology of cardiovascular complications in patients with APS and possible treatment options.

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Patients with APS have endothelial dysfunction, accelerated endothelial proliferation and intimal hyperplasia, atherogenesis, platelet activation, inflammatory products secretion and coagulation-fibrinolytic dysregulation. Cardiovascular complications include accelerated atherosclerosis, acute coronary syndrome, Libman-Sacks endocarditis, cardiomyopathy and venous, arterial or intracardiac thrombi. Moreover, pulmonary hypertension and peripheral microvascular dysfunction are common findings.

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Management of these patients is not well documented. The role of primary thrombosis prevention remains controversial in individuals with positive antiphospholipid antibodies. Treatment of traditional cardiovascular risk factors according to current guidelines for the prevention of cardiovascular disease in the general population is recommended for primary prevention of APS. Anticoagulation therapy with unfractionated or low-molecular-weight heparin overlapped with a vitamin K antagonist remains the mainstay of the treatment for APS patients with venous thrombosis, whereas direct oral anticoagulants are not yet recommended. Data are scarce regarding the secondary arterial thrombosis prevention and it is not clear whether dual or triple antithrombotic therapy is necessary. To date, it is recommended to follow current guidelines for the management of acute coronary syndrome in the general population. New treatment targets are promising options for patients with catastrophic APS.

Clinical characteristics and thrombosis outcomes of paediatric antiphospholipid syndrome: analysis of 58 patients

The study aims to analyse the clinical and immunological manifestations of paediatric antiphospholipid syndrome (APS) in patients, based on the 2006 revised classification criteria of definite APS. Fifty-eight paediatric patients with APS were enrolled and analysed retrospectively. A total of 37 female and 21 male patients with a mean age of 14 ± 3 years at disease onset were included. Fourteen (24%) cases were primary APS, and 40 (69%) cases were secondary to systemic lupus erythaematosus (SLE). Anti-nuclear antibody (ANA) positivity and hypocomplementemia were more common in secondary APS than in primary APS. The most common manifestations of thrombosis were deep vein thrombosis of the lower extremities (25 cases, 37%). Non-thrombotic manifestations were mainly immunologic thrombocytopenia, autoimmune haemolytic anaemia, skin lesions, arthritis, pulmonary hypertension, heart valve vegetations and spontaneous abortion. LA, ACL and anti-β2GPI were positive in 42 (95%), 28 (64%) and 34 (77%) cases, respectively. Over half (23 cases, 52%) of the patients were triple-positive for antiphospholipid (aPL) antibodies. Among patients with single-positive LA and anti-β2GPI, the proportion with venous thrombosis was 100% (5 cases) and 0% (0 cases), respectively. The arterial thrombosis proportions were 22% (5 cases), 21% (3 cases) and 14% (1 case) in the triple-, double- and single-aPL-positive groups, respectively (P > 0.05). Fifty-three (91%) cases were followed up for 3 to 140 months, with a median time of 32 months. Seven (13%) cases had recurrences or appearances of thrombosis during follow-up, all of which were double- or triple-aPL positive. APS in the paediatric patients is mostly secondary to SLE. ANA positivity and hypocomplementemia are more common in secondary APS, but there are no differences in the other clinical manifestations between the primary and secondary APS groups. Deep vein thrombosis is the most common thrombotic event. Positive LA may increase the risk of venous thrombosis. Multiple-aPL positivity does not increase the proportion of thrombosis. Long-term anticoagulant or antiplatelet therapy is needed to prevent thrombosis recurrence in double- or triple-positive aPL cases.

Lack of Platelet Activation Reflected by Circulating Soluble Glycoprotein V in Pre-eclampsia

Pre-eclampsia (PE) is a human pregnancy-specific disorder of unknown aetiology. Although the quantitative relationship between platelet aggregation in PE is not clearly defined yet, we aimed to investigate the possible relationship between PE and platelet glycoprotein V (GPV), which is an integral platelet membrane protein involved in the function of the GPIb-V-IX receptor. Fifty patients with PE and 37 normotensive pregnant women (controls) were enrolled in this study. Fasting blood samples were collected and soluble GPV (sGPV) levels were determined using a commercially available enzyme immunoassay. No statistically significant difference in sGPV was found between PE patients and control subjects. There was no correlation between sGPV and platelet counts or between pregnancy duration and platelet counts. Further clinical and experimental investigations are needed to elucidate the pathological processes involved in the development of PE in complicated pregnancies.

Is there a link between mean platelet volume and thrombotic events in antiphospholipid syndrome?

The antiphospholipid syndrome (APS) is an autoimmune disease characterized by the production of antiphospholipid antibodies (aPL) that promote vascular thrombosis and pregnancy loss. APS can occur in the absence of underlying or associated disease (primary APS) or in combination with other diseases (secondary APS). Mean platelet volume (MPV) is largely regarded as a useful surrogate marker of platelet activation. We aimed to investigate if there is a relationship between MPV and thrombotic events in APS. The study consisted of 22 patients and 22 healthy controls. Group 1 is defined as all the patients in the first day of thrombotic event. Group 2 is defined as the same patient population three months after the thrombotic event. The erythrocyte sedimentation rate, C-reactive protein, white blood cell count, platelet count, and MPV levels were retrospectively recorded from patient files. Statistical analyses showed that MPV was significantly higher in group 1 than group 2 (p < 0.0001) and healthy controls (p < 0.05). However, there was no difference between group 2 and healthy controls (p = 0.888). WBC, hemoglobin and other platelet indices such as platelet distribution width and platecrit did not differ in groups. In conclusion, MPV was increased at initial thrombotic event of APS, and then it was normalized three months later by therapeutic interventions. To our knowledge, this is the first study demonstrating a correlation between MPV and thrombotic events in APS.

Impaired fibrinolysis in the antiphospholipid syndrome

The antiphospholipid syndrome (APS) is characterized by venous and/or arterial thrombosis, or recurrent fetal loss, in the presence of antiphospholipid antibodies (APL). The pathogenesis of APS is multifaceted and involves numerous mechanisms including activation of endothelial cells, monocytes, and/or platelets; inhibition of natural anticoagulant pathways such as protein C, tissue factor inhibitor, and annexin A5; activation of the complement system; and impairment of the fibrinolytic system. Fibrinolysis--the process by which fibrin thrombi are remodeled and degraded--involves the conversion of plasminogen to plasmin by tissue plasminogen activator (tPA) or urokinase-type plasminogen activator, and is tightly regulated. Although the role of altered fibrinolysis in patients with APS is relatively understudied, several reports suggest that deficient fibrinolytic activity may contribute to the pathogenesis of disease in these patients. This article discusses the function of the fibrinolytic system and reviews studies that have reported alterations in fibrinolytic pathways that may contribute to thrombosis in patients with APL. Some of these mechanisms include elevations in plasminogen activator inhibitor-1 levels, inhibitory antibodies against tPA or other components of the fibrinolytic system, antibodies against annexin A2, and finally, antibodies to beta(2)-glycoprotein-I (beta(2)GPI) that block the ability of beta(2)GPI to stimulate tPA-mediated plasminogen activation.

Assessment of thrombophilic abnormalities during the active state of inflammatory bowel disease

BACKGROUND/AIMS

Thromboembolic disease has been recognized as a complication of inflammatory bowel disease (IBD). The relative contributions of inherited or acquired thrombophilia and the inflammatory response to the mechanism of this tendency are unclear. Thrombotic events are more common in active disease although significant numbers also occur spontaneously. The aim of this study was to investigate common thrombophilic markers in patients with active IBD.

METHODS

Twenty-six patients with IBD who had active disease, and 40 sex- and age-matched non-IBD patients were recruited into the study. For all the subjects, complete blood counts, C-reactive protein levels, erythrocyte sedimentation rate, International normalized ratio, activated partial thromboplastin time, and levels of lupus anticoagulant, anticardiolipin antibodies (ACA IgG), proteins C and S, antithrombin-III (AT-III), and factor V were measured.

RESULTS

The International normalized ratio, activated partial thromboplastin time, and levels of proteins C and S were comparable between the two groups. However, antithrombin-III levels were significantly lower in the IBD group as compared with that in the healthy control group (P < 0.001). ACA IgG was detected in one patient in the IBD group. Factor V Leiden mutation was present in 3.8% of the patients in the IBD group, whereas the prevalence was 2.5% in the control group. Significantly elevated platelet counts were observed in patients with active Crohn's disease compared with that in the control group (P < 0.001), but they were not significantly increased in active ulcerative colitis (P = 0.231).

CONCLUSIONS

The present study failed to establish a strong association between the common thrombophilic markers and the active clinical course of IBD, with the exception of high platelet counts and lower levels of AT-III in the IBD group as compared with those in the control group. All other parameters of thrombophilia were comparable between the two groups.

The Activated Seven Lupus Anticoagulant Assay Detects Clinically Significant Antibodies

Lupus anticoagulants are a heterogeneous group of autoantibodies detected by their effects on phospholipid-dependent coagulation assays. Persistent lupus anticoagulants are associated with thrombotic disease, but not all are clinically significant. Antibody heterogeneity and reagent and test variability dictate that at least 2 tests, of different types, should be used to screen lupus anticoagulants. The objective of this study was to investigate whether the activated seven lupus anticoagulant assay detects clinically significant antibodies. Eighty-two patients with antiphospholipid syndrome (APS) and 32 with systemic lupus erythematosus + positive for activated seven lupus anticoagulant and who were without thrombosis, who were positive by activated seven lupus anticoagulant assay, were investigated for lupus anticoagulants by dilute Russell's viper venom time, dilute activated partial thromboplastin time, and Taipan snake venom time, and for anticardiolipin antibodies. Fifty-seven of the APS patients were positive for lupus anticoagulants in multiple assays, 25 in activated seven lupus anticoagulant alone. Fourteen of the latter group were previously positive in other antiphospholipid antibodies assays, and 11 had only been positive for lupus anticoagulants by activated seven lupus anticoagulant. Twenty-eight had elevated anticardiolipin antibodies, 6 of whom were from the group that was positive in activated seven lupus anticoagulant only. Eight of the systemic lupus erythematosus + lupus anticoagulants (without thrombosis) patients were positive for lupus anticoagulant by activated seven lupus anticoagulant alone and had only been positive in activated seven lupus anticoagulant previously, and none had elevated anticardiolipin antibodies. The remaining 24 patients were lupus-anticoagulant positive in multiple assays, and 9 had elevated anticardiolipin antibodies. Dilute Russell's viper venom time and Dilute activated partial thromboplastin time are widely used to detect lupus anticoagulants and are considered to detect clinically significant antibodies. Activated seven lupus anticoagulant detected antibodies in APS patients who were positive by these assays and also lupus anticoagulants undetectable by the dilute Russell's viper venom time/dilute activated partial thromboplastin time reagents used, demonstrating its utility as a first-line or second-line assay.

Controversies and unresolved issues in antiphospholipid syndrome pathogenesis and management

While much is understood concerning the clinical features of patients with antiphospholipid syndrome (APS), many issues remain. The proper designation of patients with "definite" APS and the correct categorization of patients by both laboratory and clinical features are matters of ongoing debate. Recent proposals have identified new subsets of patients who have many typical features of APS but either do not fit the criteria for a "definite" diagnosis or have initially negative laboratory tests for antiphospholipid antibodies. Meanwhile, decisions about laboratory tests are based on expert opinion, rather than the results of controlled trials. As for treatment, many guidelines are offered, but few are backed by data from strong clinical trials. This article summarizes the clinical questions remaining to be answered and debates concerning pathogenesis, diagnosis, and management.

The search for a common thrombophilic state during the active state of inflammatory bowel disease

The clinical course of inflammatory bowel disease (IBD) is frequently associated with thromboembolic complications. The aim of this study was to investigate common thrombophilic markers in Turkish patients with active IBD. Twenty-seven consecutive patients with IBD who were followed-up at the Hacettepe University Hospital were recruited. All the patients were in the active disease state. International normalized ratio, activated partial thromboplastin time, lupus anticoagulant, anticardiolipin IgG, IgM antibodies, protein C, protein S, antithrombin-III, factor V, and factor II mutation of all the IBD patients and of a sex-matched and age-matched control group of non-IBD patients were measured. International normalized ratio, activated partial thromboplastin time, protein C, protein S, lupus anticoagulant, anticardiolipin IgG and IgM, and Proteins C and S mutations were comparable between the 2 groups, but antithrombin-III was significantly lower in the IBD group compared with healthy control group (P<0.0001). As a conclusion, it is reasonable to assume that there may be a subpopulation of the patients with IBD, in whom thrombophilic abnormalities might be important for either disease manifestation or for thrombotic complications. Those hemostatic abnormalities could be either inherited or secondary to the ongoing disease process. Routine screening for the common markers of thrombophilia does not seem to be warranted unless simultaneous arterial and venous thrombosis, major organ thrombosis, strong family history of thrombophilia, unusual and recurrent thrombosis resistant to standard anticoagulant therapy are present. Further studies are definitely required to clarify these complicated associations.

Clinical characteristics of stroke patients with antiphospholipid antibodies

BACKGROUND

Antiphospholipid syndrome is important as a cause of ischemic stroke, although clinical characteristics of the syndrome are not well documented.

METHODS

We analyzed differences in clinical characteristics between 40 antiphospholipid-antibody (aPL)-positive and 40 aPL-negative stroke patients.

RESULTS

Stroke patients with aPL were significantly younger and were more likely to be women in comparison with stroke patients without aPL. Valvular heart disease, neurological complications and hematological disorders were more frequent in the aPL-positive group. The mean value of thrombin-antithrombin III complex was significantly lower in the aPL-positive group. Cerebral infarctions in the carotid system were less and large-artery lesions more frequent in the aPL-positive patients.

CONCLUSIONS

Stroke patients with aPL have clinical characteristics distinct from stroke patients without aPL.