Anti-phospholipid syndrome: Current opinion on mechanisms involved, laboratory characterization and diagnostic aspects

Management of cerebrospinal fluid rhinorrhea as a rare complication of antiphospholipid syndrome

Background

Antiphospholipid syndrome is a complex autoimmune condition associated with the formation of recurrent thrombosis in any vascular bed throughout the body. Jugular vein thrombosis is very rare with only a 0.9% occurrence and is not typically associated with cerebrospinal rhinorrhea as a result of raised intracranial pressure.

Case Description

A 54-year-old patient presented with a 9-month history of cerebrospinal fluid (CSF) rhinorrhea and headache on a background of antiphospholipid syndrome. Investigations showed a superior vena cava (SVC) and right internal jugular vein (IJV) obstruction with moderately elevated intracranial venous pressures. Her magnetic resonance imaging (MRI) brain was consistent with a CSF leak. The patient underwent successful endovascular stenting of her obstructed SVC and right IJV followed by surgical repair of a herniating meningocele in the posterior left ethmoid air cells.

Conclusion

CSF rhinorrhea is uncommon and never previously reported associated with SVC thrombosis induced by antiphospholipid syndrome. A combination of endovascular techniques and surgical repair is recommended for this challenging presentation.

Cerebral Sinus Vein Thrombosis and Gender: A Not Entirely Casual Relationship

Cerebral sinus venous thrombosis (CSVT) is a relatively rare acute disorder of cerebral circulation, but it can potentially be associated with serious sequelae and a poor prognosis. The neurological manifestations associated with it are often not adequately taken into consideration given the extreme variability and nuances of its clinical presentation and given the need for radiological methods suitable for this type of diagnosis. CSVT is usually more common in women, but so far there are little data available in the literature on sex-specific characteristics regarding this pathology. CSVT is the result of multiple conditions and is therefore to be considered a multifactorial disease where at least one risk factor is present in over 80% of cases. From the literature, we learn that congenital or acquired prothrombotic states are to be considered extremely associated with the occurrence of an acute episode of CSVT and its recurrences. It is, therefore, necessary to fully know the origins and natural history of CSVT, in order to implement the diagnostic and therapeutic pathways of these neurological manifestations. In this report, we summarize the main causes of CSVT considering the possible influence of gender, bearing in mind that most of the causes listed above are pathological conditions closely linked to the female sex.

Autoimmune complications of COVID-19 and potential consequences for long-lasting disease syndromes

The latest WHO report determined the increasing diversity within the CoV-2 omicron and its descendent lineages. Some heavily mutated offshoots of BA.5 and BA.2, such as BA.4.6, BF.7, BQ.1.1, and BA.2.75, are responsible for about 20% of infections and are spreading rapidly in multiple countries. It is a sign that Omicron subvariants are now developing a capacity to be more immune escaping and may contribute to a new wave of COVID-19. Covid-19 infections often induce many alterations in human physiological defense and the natural control systems, with exacerbated activation of the inflammatory and homeostatic response, as for any infectious diseases. Severe activation of the early phase of hemostatic components, often occurs, leading to thrombotic complications and often contributing to a lethal outcome selectively in certain populations. Development of autoimmune complications increases the disease burden and lowers its prognosis. While the true mechanism still remains unclear, it is believed to mainly be related to the host autoimmune responses as demonstrated, only in some patients suffering from the presence of autoantibodies that worsens the disease evolution. In fact in some studies the development of autoantibodies to angiotensin converting enzyme 2 (ACE2) was identified, and in other studies autoantibodies, thought to be targeting interferon or binding to annexin A1, or autoantibodies to phospholipids were seen. Moreover, the occurrence of autoimmune heparin induced thrombocytopenia has also been described in infected patients treated with heparin for controlling thrombogenicity. This commentary focuses on the presence of various autoantibodies reported so far in Covid-19 diseases, exploring their association with the disease course and the durability of some related symptoms. Attempts are also made to further analyze the potential mechanism of actions and link the presence of antibodies with pathological complications.

Clinical Characteristics and Management of Cerebral Venous Sinus Thrombosis in Patients With Antiphospholipid Syndrome: A Single-Center Retrospective Study

Antiphospholipid syndrome (APS) with cerebral venous sinus thrombosis (CVST) is a relatively rare phenomenon, and this observational study aimed to investigate the clinical characteristics of APS patients complicated with CVST. We retrospectively investigated the clinical characteristics of CVST events in APS and compared differential characteristics and associated factors between APS patients with and without CVST. Twenty-one CVST patients with APS were enrolled including 14 females (9.4%) and 7 males (5.8%). The median age and disease duration at onset of CVST was 33 years (IQR 28-48) old and 1.3 months (IQR 0.7-4), respectively. Among APS patients with CVST, 12 (57.1%) cases presented with neurologic symptoms of CVST as the initial manifestation. Onset of CVST was mainly chronic (52.4%). Headache (90.5%) was the most common neurological symptom. The common locations of CVST were transverse sinus (76.2%) and superior sagittal sinus (57.1%), with more frequently (76.2%) dual or multiple sinuses involved. All patients with CVST were treated with anticoagulant, and 5 (23.8%) patients received endovascular therapy. Sixteen (84.2%) patients had good outcomes and 3 (15.8%) patients died at last follow-up. There were no significant differences (P > 0.05) between two groups in the analysis of related APS indicators. There were no significant differences (P > 0.05) between two groups in the analysis of related APS indicators. Although APS complicated with CVST is rare and predominately chronic developed. The evaluation of CVST should be performed for APS patients with intracranial hypertension syndrome. The routine screening of antiphospholipid antibodies (aPLs) is highly recommended in unexplained CVST patients. Most CVST patients with APS will have a good prognosis after treatment, and endovascular therapy is an alternative treatment.

Lupus Antibody Mimicking Reduced Plasmatic Coagulation in a Patient With Atrial Fibrillation and Ischemic Stroke

Background: Lupus anticoagulant (LA) owns procoagulant properties in vivo and prolongs phospholipid-dependent clotting times in vitro. The prolonged in vitro clotting time can be misinterpreted as a bleeding disorder. In some cases, it is necessary to differentiate LA-associated in vitro changes from in vivo coagulation factor deficiency. In this case, we used different laboratory testing in a patient with ischemic stroke and reduced prothrombin time (PT) to identify an in-vitro effect of LA excluding an in-vivo bleeding disorder. Methods: The activity of various coagulation factors was evaluated both with recombinant thromboplastin Innovin (Siemens Healthcare) and reagent tissue extracted thromboplastin Thromborel® (Siemens Healthcare). Moreover, a 1:1 plasma mixing test with standard plasma was performed. In order to exclude the interaction of tromboplastin and LA thromboplastin, an independent global coagulation test, thromboelastography, was used. Diluted-Russel-Viper-Venom (dRVVT) assay was applied to detect the presence of LA detection. Results: The activity of several coagulation factors measured with recombinant thromboplastin Innovin (Siemens Healthcare) showed a reduced activity of the following coagulation factors: Factor V (20.9%), Factor VII (23.8%), Factor X (19.7%) and international normalized ratio (INR) of 2.33. Re-assessment of the factor's activity with another reagent tissue extracted thromboplastin Thromborel® (Siemens Healthcare) showed a normalization of INR and factor's activity in comparison to thromboplastin reagent Innovin®: Factor V (77%), Factor VII (45.4%), Factor X (64.2%), and INR of 1.28. A plasma mixing study with 1:1 standard plasma revealed reduced (<50%) normalization of INR as well as coagulation factor's activity confirming a LA-inhibitor in the patient plasma. Diagnostic LA testing was also performed with dRVVT assay showing a significantly prolonged (112.8 s) test time. Thromboelastography revealed no abnormalities. Conclusions: Different thromboplastin reagents and plasma mixing tests as well as thromboplastin independent coagulation tests may be helpful to differentiate LA and in vitro changes from in vivo factor deficiency in patients with LA.

Unveiling the complex effects of direct oral anticoagulants on dilute Russell's viper venom time assays

INTRODUCTION

Dilute Russell viper venom time (dRVVT) assays can be affected by direct oral anticoagulants (DOACs), which may cause false-positive results. However, there are conflicting results indicating significant differences between different reagents and DOACs.

OBJECTIVES

To evaluate the effect of DOACs on dRVVT assays.

MATERIAL AND METHODS

Samples were prepared by adding DOAC (dabigatran, rivaroxaban, apixaban, or edoxaban) to pooled normal plasma in the concentration range 0 to 800 µg/L. Six integrated dRVVT reagents were used, all composed of a screen assay (low phospholipid content) and a confirm assay (high phospholipid content). The screen/confirm dRVVT results were expressed as normalized ratios. To further evaluate the observed differences between tests and DOACs, addition of synthetic phospholipids was used.

RESULTS

The dRVVT ratios increased dose dependently for all DOACs, with four of the six tests and the DOAC rivaroxaban having the greatest effect. With one test, the ratios were almost unaffected with increasing DOAC concentration, whereas another test revealed a negative dose dependency for all DOACs. Variable DOAC effects can be explained by different effects on dRVVT screen and confirm clotting time. Adding synthetic phospholipids to samples containing rivaroxaban resulted in greatly reduced screen clotting times and thereby lower calculated dRVVT ratios.

CONCLUSIONS

There is a great variability in the dRVVT test result with different DOACs. The dRVVT ratios are unaffected for some reagents and this can be explained by an equal dose-dependent effect on both screen and confirm assays. The phospholipid type and content of the different reagents may contribute to the observed differences.

Annexin V expression on CD4+ T cells with regulatory function

Regulatory T (Treg) cells induce immunologic tolerance by suppressing effector functions of conventional lymphocytes in the periphery. On the other hand, immune silencing is mediated by recognition of phosphatidylserine (PS) on apoptotic cells by phagocytes. Here we describe expression of the PS-binding protein Annexin V (ANXA5) in CD4⁺  CD25^hi Treg cells at the mRNA and protein levels. CD4⁺  ANXA5⁺ T cells constitute about 0·1%-0·6% of peripheral blood CD3⁺ T cells, exhibit co-expression of several Treg markers, such as Forkhead box P3, programmed cell death protein-1, cytotoxic T-lymphocyte antigen-4 and CD38. In vitro, ANXA5⁺ Treg cells showed enhanced adhesion to PS⁺ endothelial cells. Stimulated by anti-CD3 and PS⁺ syngeneic antigen-presenting cells CD4⁺  ANXA5⁺ T cells expanded in the absence of exogenous interleukin-2. CD4⁺  ANXA5⁺ T cells suppressed CD4⁺  ANXA5^- T-cell proliferation and mammalian target of rapamycin phosphorylation, partially dependent on cell contact. CD4⁺  ANXA5⁺ T-cell-mediated suppression was allo-specific and accompanied by an increased production of anti-inflammatory mediators. In vivo, using a model of delayed type hypersensitivity, murine CD4⁺  ANXA5⁺ T cells inhibited T helper type 1 responses. In conclusion, we report for the first time expression of ANXA5 on a subset of Treg cells that might bridge classical regulatory Treg function with immune silencing.

High frequency of anti-protein Z antibodies in patients with anticardiolipin antibodies

Protein Z (PZ) is a vitamin K-dependent protein involved in the down-regulation of coagulation by forming a complex with the protein Z-dependent protease inhibitor. The complex inhibits the activated factor X on phospholipid surface. Presence of anti-PZ (aPZ) antibodies was first described in women with pathological pregnancies but the significance of aPZ antibodies in other pathological situations was poorly studied. In this work we analyzed the frequency of aPZ antibodies in a series of 86 consecutive patients with anticardiolipin (aCL) antibodies and studied the association of aPZ with other antiphospholipid (aPL) antibodies [lupus anticoagulant (LAC) and anti-ß2GP-1 antibodies] and the clinical signification of these aPZ antibodies in term of thrombosis or fetal loss. Anti-PZ antibodies (IgG and IgM) were detected using commercially available ELISA assays. The frequency of aPZ antibodies was 40.7% in the patient group versus 6.8% in a group of 59 healthy volunteers (p < 0.0001). The frequency of aPZ antibodies significantly increases (p < 0.05) in patients with a double or triple positivity of aPL antibodies and a higher frequency of aPZ antibodies was observed in patients with LAC (57.7%) than in patients without LAC (25.6%, p = 0.02). There were no significant differences in aPZ antibodies frequency between patients with and without thrombotic events. Interestingly, among the 8 women with recurrent foetal losses, aPZ antibodies were observed in 7 cases, in agreement with previous observations suggesting that aPZ antibodies may be associated with obstetrical complications.