Is there a microangiopathic antiphospholipid syndrome?

Update on the Laboratory Diagnosis of Lupus Anticoagulant: Current Challenges and Clinical Involvement

Lupus anticoagulant (LAC) is a heterogeneous mix of autoimmune antibodies that prolongs phospholipid-dependent clotting assays. Its diagnosis can be a real challenge in the hemostasis laboratory. In this review, the author describes the main pitfalls affecting the preanalytical phase and how to proceed to reduce interferences. Because of the heterogeneity of these autoantibodies, two assays with different mechanism of action should be performed to detect the majority of LACs. The dilute Russell's viper venom test and the use of a reagent very sensitive to LAC derived from the activated partial thromboplastin time, using silica as the activator, are the most frequent techniques. The algorithms for LAC detection are reported here, and every laboratory is encouraged to introduce its own diagnostic procedure. Results should be expressed in ratio to reduce inter- and intravariability. In addition, the effect of anticoagulation in LAC assays and possible strategies for a correct diagnosis are provided.

Addison's Disease in the Course of Recurrent Microangiopathic Antiphospholipid Syndrome-A Clinical Presentation and Review of the Literature

The article presents a male patient with adrenocortical insufficiency in the course of antiphospholipid syndrome (APS). It also describes recurrent exacerbations of his clinical status, characteristic of microangiopathic antiphospholipid syndrome (MAPS) which had been misdiagnosed as a disseminated intravascular coagulopathy (DIC) syndrome due to sepsis with multi-organ failure, including heart, kidneys, and liver. Issues related to pathogenesis, clinical symptoms, differential diagnosis, and treatment of APS in the context of presently distinguished subtypes of this syndrome have been addressed. The role of vascular endothelial cell activation and the influence of coagulation patterns on the development of APS continuum clinical symptoms have also been mentioned. In addition, this paper highlights that the diagnosis of APS should be considered in patients with adrenal insufficiency and abdominal pain, even without any prior history of thromboembolic diseases, as well as in the course of DIC, especially without predisposing factors.

[Thrombotic microangiopathy in rheumatology: a link between thrombosis and autoimmunity]

Uncontrolled hypercoagulation and inflammation (thromboinflammation), which are both independent and closely related and amplifying each other pathological processes, form the basis for pathogenesis of a wide range of diseases and complications, including immuno-inflammatory (autoimmune) rheumatic diseases, with the development of potentially fatal injuries of internal organs. Thrombotic microangiopathy is one of the most prominent prototypes of thromboinflammatory pathological conditions. The close link between environmental factors, hemostasis genetic defects and the complement system, inflammation and autoimmunity as pathogenetic mechanisms of microthrombosis draws particular attention to studying thrombotic microangiopathy in immuno-inflammatory rheumatic diseases, primarily systemic lupus erythematosus, antiphospholipid syndrome and scleroderma renal crisis. In future, these studies may be important for expanding the idea of the role of autoimmune mechanisms in pathogenesis of critical hemostasis disorders in human diseases, and for developing new approaches to therapy. Recently, special attention has been paid to the treatment of systemic lupus erythematosus and antiphospholipid syndrome with eculizumab, which is humanized monoclonal IgG2/4k antibody that blocks the complement component C5a and the membrane attack complex (C5b-9) formation, and which is registered for the treatment of atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria, as well as severe forms of myasthenia gravis and neuromyelitis optica. Further studies in this direction will create prerequisites for improving the prognosis not only in patients with orphan disorders, but also for widespread human diseases.

Clinical characteristics and risk factors of microvascular involvement in primary antiphospholipid syndrome: a longitudinal single-center study in China

OBJECTIVES

The objective of this study was to investigate risk factors of microvascular involvement and survival in Chinese patients with primary antiphospholipid syndrome.

METHODS

In this single-center, retrospective study, we enrolled 112 patients with a confirmed diagnosis of primary antiphospholipid syndrome who were admitted to Peking Union Medical College Hospital from January 2004 to December 2016. Demographic data, clinical characteristics, laboratory results, and follow-up records were collected.

RESULTS

A total of 112 patients with primary antiphospholipid syndrome were studied. Microvascular involvement was identified in 21 patients (18.75%). Patients with microvascular involvement experienced fewer episodes of arterial or venous thrombosis (28.6% vs. 84.6%) and a higher incidence of thrombocytopenia (85.7% vs. 54.9%), respectively. Low complement and elevated high-sensitivity CRP levels were observed more frequently in the microvascular group compared with the non-microvascular group (complement 38.1% vs. 18.7%; high-sensitivity CRP 71.4% vs. 31.9%, respectively). Anti-β2-glycoprotein I antibodies were more prevalent in patients with microvascular involvement than in patients without (66.7% vs. 33.0%, respectively). Multivariate logistic regression analysis revealed that thrombocytopenia (odds ratio = 4.523, 95% confidence interval 1.139-17.962), elevated high-sensitivity CRP levels (odds ratio = 6.385, 95% confidence interval 1.969-20.704), and anti-β2-glycoprotein I antibody positivity (odds ratio = 5.042, 95% confidence interval 1.555-16.352) were independent risk factors for microvascular involvement. A Kaplan-Meier analysis revealed that survival was significantly poorer in patients with microvascular involvement compared with patients without (p = 0.0278).

CONCLUSIONS

In addition to arterial and venous thrombosis, antiphospholipid syndrome can affect the microvasculature of select organs. It is thus important for clinicians to be aware that antiphospholipid syndrome-associated microvascular involvement has a unique pathogenesis and can be a life-threatening condition.

Microangiopathic antiphospholipid antibody-associated syndrome in a pregnant lady

We describe a gravid 37-year-old Chinese lady with known triple positive primary antiphospholipid syndrome with previous recurrent deep vein thrombosis and early spontaneous miscarriages. She was managed with low-molecular weight heparin, aspirin, hydroxychloroquine, prednisolone and monthly intravenous immunoglobulin. She presented with recurrent per-vaginal bleeding at 22 weeks of gestation and was found to have abruptio placentae. Anti-coagulation was held off. She subsequently delivered a stillborn at 24 weeks and anti-coagulation was restarted. Day 5 post-delivery, she developed HELLP, with hemolytic anaemia (Hb 10.1 g/dL, haptoglobin <30 g/L, LDH 2206 U/L), elevated transaminases (AST 1196 U/L, ALT 1130 U/L) and thrombocytopenia (platelet 28 × 10^9/L). There were also episodes of acute severe headache and abdominal pain assessed to be secondary to microvascular ischemia as CT did not reveal any thrombosis. Her blood pressure hovered persistently above systolic 180 mmHg, and required at least three anti-hypertensives. These were coupled with a new onset proteinuria of 2 to 3 g/day. There was no evidence of disseminated intravascular coagulation. She was assessed to have microangiopathic antiphospholipid syndrome and was started on plasmapheresis. On Day 10 post-partum, the patient complained of foul-smelling vaginal discharge and was found to have retained products of conception, which was immediately evacuated. Her course was followed by poly-microbial sepsis secondary to Enterococcus fecalis, Klebsiella Pneumoniae and Escherichia coli. The patient was further treated with imipenem and she completed eight exchanges of plasmapheresis followed by five days of intravenous immunoglobulins with good clinical and biochemical improvement.

The significance and management of thrombocytopenia in antiphospholipid syndrome

The association between antiphospholipid antibodies (aPL) and clinical problems goes beyond what is stated in the antiphospholipid syndrome (APS) classification criteria, namely thrombosis and pregnancy morbidity, and thrombocytopenia is the most common non-criteria hematologic manifestation of aPL with a frequency ranging from 20 to 50 %. Thrombocytopenia is rarely severe, and hemorrhage is far less common than thrombosis. However, when anticoagulation is considered, it may constitute a clinical problem with increased bleeding risk. Furthermore, thrombocytopenia represents a risk factor for thrombosis in aPL-positive patients. Therefore, it is important to understand the pathogenesis and the clinical associations of thrombocytopenia to build the right medical approach in aPL-positive patients. In this paper, we review the literature on aPL/APS-associated thrombocytopenia and briefly discuss the other conditions that can result in thrombocytopenia as they have commonalities with APS and their recognition is important to establish the most appropriate treatment strategy.

Antiphospholipid syndrome in renal transplantation

Antiphospholipid syndrome (APS) may occur in isolation or in association with systemic lupus erythematosus (SLE), with the potential to cause renal failure via several distinct pathologies. Renal transplantation in the presence of APS carries a risk of early graft loss from arterial or venous thrombosis, or thrombotic microangiopathy (TMA). Whilst perioperative anticoagulation reduces the risk of large vessel thrombosis, it may result in significant haemorrhage, and its efficacy in preventing post-transplant TMA is uncertain. Here, we report a patient with end-stage kidney disease (ESKD) due to lupus nephritis and APS, in whom allograft TMA developed soon after transplantation despite partial anticoagulation. TMA resolved with plasma exchange-based therapy albeit with some irreversible graft damage and renal impairment. We discuss the differential diagnosis of post-transplant TMA, and current treatment options.

Capillaroscopic pattern in systemic lupus erythematosus and undifferentiated connective tissue disease: what we still have to learn?

In rheumatology, specific is the capillaroscopic pattern in systemic sclerosis (SSc), the so-called "scleroderma type". Capillaroscopic pattern in systemic lupus erythematosus (SLE) is less specific and includes a wide range of microvascular changes-"SLE-type" capillaroscopic pattern, non-specific findings and in a small percentage "scleroderma-like" pattern. The latter finding is currently associated with a potential subclinical overlap with SSc. Various microvascular changes have been observed in a different proportion of patients with undifferentiated connective tissue disease (UCTD). The aim of the study was to evaluate the capillaroscopic changes in SLE and UCTD. Patients from the following groups were included in the study: 30 female patients with SLE (mean age, 49 ± 15.4 years), 31 patients with UCTD (mean age, 50 ± 17 years; 30 females and 1 male); 34 age- and sex-matched healthy volunteers were examined as a control group. Nailfold capillaroscopy was performed using videocapillaroscope Videocap 3.0 (DS Medica). Capillaroscopic findings were compared with clinical and laboratory data of the patients. At capillaroscopic examination, the most frequent capillaroscopic changes in SLE patients were the presence of elongated capillaries in 43 % (13/30), an increased tortuosity in 70 % (21/30) and a prominent subpapillary plexus in 60 % (18/30) of the cases. In 80 % (24/30) of the patients, dilated capillaries were found; in 6.6 % (2/30), giant capillary loops; and in 16.6 % (5/30), haemorrhages. In 50 % of the patients, an "SLE-type" capillaroscopic pattern was found. In 30 % (9/30) of the cases the capillaroscopic examination revealed "non-specific changes", in 6.6 % (2/30) of the patients it was found a normal capillaroscopic pattern and in 13.3 % (4/30) a "scleroderma-like" pattern. Positive tests for ANA were detected in 73.3 % (11/15) of the patients with "SLE-type" capillaroscopic pattern. In all the patients with "scleroderma-like" capillaroscopic finding, positive autoantibodies with a high titre were found, without signs for overlap with other connective tissue disease (CTD). In two out of four patients with such capillaroscopic findings, a vasculitis of peripheral vessels was evident and in the other two secondary RP and high immunologic activity. A "scleroderma-like" pattern was found in 38 % (12/31) of the patients with UCTD. In 51 % (16/31) of the patients from this group, "non-specific" capillaroscopic findings were observed. For the evaluation of the predictive value of capillaroscopic pattern for the development of a distinct rheumatic disorder in patients with UCTD, a longer period of follow-up is necessary. In SLE patients, it has been found that capillaroscopic examination reveals microvascular changes also in the absence of RP. Here, the results from the study illustrate the correlation between capillaroscopic changes and immunological profile. "Scleroderma-like" capillaroscopic pattern may be observed in the context of active vasculitis of peripheral vessels as well as in patients with secondary RP and high immunologic activity. It does not have an obligatory association with an overlap syndrome with other CTD. Capillaroscopic findings in UCTD are heterogeneous. The potential of capillaroscopic examination in UCTD for evaluating the prognosis of the disease needs to be revealed through long-term follow-up.

Antiphospholipid antibodies promote leukocyte-endothelial cell adhesion and thrombosis in mice by antagonizing eNOS via β2GPI and apoER2

In antiphospholipid syndrome (APS), antiphospholipid antibodies (aPL) binding to β2 glycoprotein I (β2GPI) induce endothelial cell-leukocyte adhesion and thrombus formation via unknown mechanisms. Here we show that in mice both of these processes are caused by the inhibition of eNOS. In studies of cultured human, bovine, and mouse endothelial cells, the promotion of monocyte adhesion by aPL entailed decreased bioavailable NO, and aPL fully antagonized eNOS activation by diverse agonists. Similarly, NO-dependent, acetylcholine-induced increases in carotid vascular conductance were impaired in aPL-treated mice. The inhibition of eNOS was caused by antibody recognition of domain I of β2GPI and β2GPI dimerization, and it was due to attenuated eNOS S1179 phosphorylation mediated by protein phosphatase 2A (PP2A). Furthermore, LDL receptor family member antagonism with receptor-associated protein (RAP) prevented aPL inhibition of eNOS in cell culture, and ApoER2-/- mice were protected from aPL inhibition of eNOS in vivo. Moreover, both aPL-induced increases in leukocyte-endothelial cell adhesion and thrombus formation were absent in eNOS-/- and in ApoER2-/- mice. Thus, aPL-induced leukocyte-endothelial cell adhesion and thrombosis are caused by eNOS antagonism, which is due to impaired S1179 phosphorylation mediated by β2GPI, apoER2, and PP2A. Our results suggest that novel therapies for APS can now be developed targeting these mechanisms.

Update on the diagnosis, treatment, and prognosis of the catastrophic antiphospholipid syndrome

The catastrophic antiphospholipid syndrome (APS) is a potentially life-threatening condition, the diagnosis of which requires a high degree of clinical awareness on the part of attending physicians. Patients with APS present with 1) clinical evidence of multiple organ involvement developed over a very short time; 2) histopathologic evidence of multiple small-vessel occlusions; and 3) laboratory confirmation of the presence of antiphospholipid antibodies, usually in high titer. A combination of anticoagulants, corticosteroids, intravenous immunoglobulins, and plasma exchanges is the basic treatment for all patients with this severe condition. Unfortunately, despite current therapies, the mortality rate is still high (around 30%). However, once patients with catastrophic APS have recovered, they usually follow a stable course with continued anticoagulation and few patients present with a relapse of the catastrophic episode.

The role of capillaroscopy in differentiation of primary and secondary Raynaud's phenomenon in rheumatic diseases: a review of the literature and two case reports

The purpose of this study is to study and systematize the current knowledge about the role of capillaroscopy in differentiation of primary and secondary Raynaud's phenomenon (RP) in rheumatic diseases. This method is a review of the literature. Capillaroscopy is of crucial value for diagnosis and differentiation of primary and secondary RP in rheumatic diseases. The appearance of abnormal capillaroscopic pattern inherits high positive predictive value for the development of systemic rheumatic disease. The most specific pattern is found in systemic sclerosis (SSc), so called "scleroderma pattern", which is characterized by the presence of dilated capillaries, hemorrhages, avascular areas and neoangiogeneis. It is found in more than 90% of patients with overt SSc. Similar changes are found in patients with dermatomyositis, mixed connective tissue disease, undifferentiated connective tissue disease and they are called "scleroderma-like pattern". Absence of abnormal capillaroscopic findings can be regarded as a diagnostic criterion for primary RP. Inclusion of pathologic capillaroscopic pattern may increase the sensitivity of ACR classification criteria for SSc. In conclusion, capillaroscopy is of crucial importance for the differentiation of primary and secondary RP in rheumatic diseases, and also in differentiation between different forms of connective tissue diseases as well as for their early diagnosis.

D-dimer level and the risk for thrombosis in systemic lupus erythematosus

BACKGROUND AND OBJECTIVES

Patients who have systemic lupus erythematosus (SLE) and manifest antiphospholipid antibodies (APA) are at increased risk for thrombosis; however, it is difficult to predict who will clot. This study tested the hypothesis that peak D-dimer level measured routinely during follow-up identifies whether a hypercoagulable state is developing and, therefore, the patient is at increased risk for thrombosis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

One hundred consecutive patients who had SLE with recurrent activity (71% renal SLE) and were evaluated for or enrolled in the Ohio SLE Study were studied. D-dimer testing was done annually and usually at SLE flare or other serious illness. When D-dimer was elevated, evaluation for thrombosis (large vessel, small vessel, or Libman-Sacks) was undertaken. Mean follow-up was 37.5 +/- 15 SD months.

RESULTS

Of those with peak D-dimer <0.5 microg/ml (n = 46), 0% thrombosed, 33% had APA. Of those with peak D-dimer 0.5 to 2.0 microg/ml (n = 19), 6% thrombosed, 44% had APA. Of those with peak D-dimer >2.0 microg/ml (n = 36), 42% thrombosed, 76% had APA. The most common causes of elevated D-dimer in the absence of demonstrable thrombosis were SLE flare and systemic infection. D-dimer levels were usually elevated for several months before thrombosis.

CONCLUSIONS

Patients with SLE and normal D-dimer levels are at low risk for thrombosis, irrespective of APA status. Those with persistent unexplained elevated D-dimer levels, particularly when >2.0 microg/ml, are at high risk for thrombosis.