The environment and antiphospholipid syndrome

The trends in the incidence and thrombosis-related comorbidities of antiphospholipid syndrome: a 14-year nationwide population-based study

Background

This study aims to provide 14-year nationwide epidemiology data to evaluate the incidence ratio of APS in Taiwan and the condition of comorbidities by analyzing the National Health Insurance Research Database.

Methods

Nineteen thousand one hundred sixty-three patients newly diagnosed as having APS during the 2000–2013 period and 76,652 controls (with similar distributions of age and sex) were analyzed.

Results

The incidence of APS increased from 4.87 to 6.49 per 10,000 person-years in the Taiwan population during 2000–2013. The incidence of APS increased with age after 20 years old, especially in the female population, and it rose rapidly after age over 60 years old. In addition, APS cohorts presented a higher proportion of diabetes mellitus, hypertension, hyperlipidemia, stroke, heart failure, atrial fibrillation, myocardial infarction, PAOD, chronic kidney disease, COPD, deep vein thrombosis, pulmonary embolism, SLE, rheumatoid arthritis, Sjogren’s syndrome, and polymyositis.

Conclusions

Our study indicated an increasing trend in APS incidence among the Taiwanese population and a relationship between APS and potential comorbidities. This large national study found that the APS risk is heavily influenced by sex and age. Thus, the distinctive sex and age patterns might be constructive given exploring potential causal mechanisms. Furthermore, our findings indicate that clinicians should have a heightened awareness of the probability of APS, especially in women in certain age groups presenting with symptoms of APS.

Drug-induced antiphospholipid syndrome: Analysis of from the WHO international database

OBJECTIVE

As with drug-induced lupus, some drugs may induce an antiphospholipid syndrome (APS). With the always growing numbers of new molecules, the list of the liable treatments evolves rapidly. We herein analyzed VigiBase, the international pharmacovigilance database, to identify drugs suspected of inducing APS.

METHODS

All the reported cases associated with "anti-phospholipid syndrome" using the preferred term level of medDRA (dictionary of regulated drug activity) when associated with anti-phospholipid antibodies in VigiBase were analyzed. For each treatment, a Bayesian disproportionality indicator (i.e. information component, IC) was calculated. A drug was significantly associated with APS if the 95% lower-end of the IC credibility interval was positive (IC₀₂₅ > 0). Drugs with potential protopathic bias were excluded.

RESULTS

From 01/11/2000 to 25/07/2021, 790 reports of suspected drug-induced APS were found in VigiBase. After excluding drugs reported by a single country and drugs with protopathic bias, fourteen drugs (n = 359 reports) were associated with APS with an IC_{0 25} > 0. These drugs were hormons: ethinylestradiol-etonogestrel and drospirenone-ethynilestradiol; platelet growth factors: eltrombopag, romiplostim; vaccines: Human Papillomavirus vaccine, hepatitis A and B vaccines and typhoid vaccine; antibiotics: minocycline; nonstreroidal anti-inflammatory: rofecoxib; biotherapy: interferon beta-1-a, etanercept; anti-hypertensive drug: hydralazine; bisphosphonates: alendronic acid and antipsychotic: olanzapine. The mean age at diagnosis of drug-induced APS was 39.2 years [29.3;47.9] and there were 63.5% of female patients. The mean delay from first exposition to drug-induced APS was 19.7 months [4.5; 38.8]. Drug-induced APS was reported as a severe side effect in 66.3% of cases: 8.4% with a life-threatening event and 2.5% of death (n = 9). A third (n = 118, 32.9%) pulmonary embolism events were reported and 4.2% (15) cerebral infarctions. 14.8% (53) cases were associated with a systemic lupus, a sub-analysis without lupus cases showed the same severity of cases.

CONCLUSION

This study identified 14 drugs potentially associated with drug-induced APS that may prove useful in the investigational work-up in any new diagnosis of APS.

TRIAL REGISTRATION NUMBER

NCT03994302.

Probable Catastrophic Antiphospholipid Syndrome with Intracerebral Hemorrhage Secondary to Epstein-Barr Viral Infection

BACKGROUND

Catastrophic antiphospholipid syndrome (CAPS) is a rare, severe variant of antiphospholipid syndrome with a high mortality rate. We report a unique case of CAPS secondary to Epstein-Barr viral (EBV) infection complicated by pulmonary and intracerebral hemorrhage. A review of the CAPS literature relevant to intensive care practice is used to outline a rational approach to diagnosis and management.

METHODS

All data are from a single patient admitted to the Neurosciences Critical Care Unit in Addenbrooke's Hospital, Cambridge, in March 2016. Medline, Web of Science, PubMed, and the Cochrane Library were searched through September 2016 without restrictions for cases of CAPS, management of CAPS in the intensive care unit, and hemorrhage complicating CAPS. The patient gave express written consent to access and publish these data.

RESULTS

This is only the second reported case of probable CAPS secondary to EBV infection. Furthermore, pulmonary and intracerebral hemorrhage is rare manifestations of this multisystem prothrombotic state which provided unique challenges to the management.

CONCLUSIONS

While rare, CAPS should be considered in any patient presenting with rapidly progressive multiorgan failure, evidence of thrombotic microangiopathy, and antiphospholipid antibodies. A high index of suspicion is required as early, aggressive, multimodal treatment with anticoagulation, and immunosuppression improves outcomes.

LDLR and PCSK9 Are Associated with the Presence of Antiphospholipid Antibodies and the Development of Thrombosis in aPLA Carriers

Introduction

The identification of the genetic risk factors that could discriminate non- thrombotic from thrombotic antiphospholipid antibodies (aPLA) carriers will improve prognosis of these patients. Several human studies have shown the presence of aPLAs associated with atherosclerotic plaque, which is a known risk factor for thrombosis. Hence, in order to determine the implication of atherosclerosis in the risk of developing thrombosis in aPLA positive patients, we performed a genetic association study with 3 candidate genes, APOH, LDLR and PCSK9.

Material & Methods

For genetic association study we analyzed 190 aPLA carriers -100 with non-thrombotic events and 90 with thrombotic events- and 557 healthy controls. Analyses were performed by χ2 test and were corrected by false discovery rate. To evaluate the functional implication of the newly established susceptibility loci, we performed expression analyses in 86 aPLA carrier individuals (43 with thrombotic manifestations and 43 without it) and in 45 healthy controls.

Results

Our results revealed significant associations after correction in SNPs located in LDLR gene with aPLA carriers and thrombotic aPLA carriers, when compared with healthy controls. The most significant association in LDLR gene was found between SNP rs129083082 and aPLA carriers in recessive model (adjusted P-value = 2.55 x 10⁻³; OR = 2.18; 95%CI = 1.49–3.21). Furthermore, our work detected significant allelic association after correction between thrombotic aPLA carriers and healthy controls in SNP rs562556 located in PCSK9 gene (adjusted P-value = 1.03 x 10⁻²; OR = 1.60; 95%CI = 1.24–2.06). Expression level study showed significantly decreased expression level of LDLR gene in aPLA carriers (P-value <0.0001; 95%CI 0.16–2.10; SE 0.38–1.27) in comparison to the control group.

Discussion

Our work has identified LDLR gene as a new susceptibility gene associated with the development of thrombosis in aPLA carriers, describing for the first time the deregulation of LDLR expression in individuals with aPLAs. Besides, thrombotic aPLA carriers also showed significant association with PCSK9 gene, a regulator of LDLR plasma levels. These results highlight the importance of atherosclerotic processes in the development of thrombosis in patients with aPLA.

Cigarette smoking, antiphospholipid antibodies and vascular events in Systemic Lupus Erythematosus

OBJECTIVE

Smoking can induce autoantibodies in persons who are genetically predisposed to rheumatoid arthritis. We investigated the association between smoking and antiphospholipid antibodies (aPL) in systemic lupus erythematosus (SLE), a question not previously addressed. Further, we explored the relationship between smoking, aPL and vascular events (arterial and venous, VE).

METHODS

In this cross-sectional study, clinical evaluation and questionnaire data were collected from 367 prevalent SLE patients. At the same time, we measured aPL (anticardiolipin (aCL), anti-β2 glycoprotein-1 (aβ2GP1) antibodies IgG/IgM/IgA, and lupus anticoagulant (LA)), and a large set of other SLE-associated autoantibodies for comparison. Association analyses using logistic regression models with smoking, (ever, former and current with never as reference) and antibody status as outcome variable were performed. As a secondary outcome, we investigated the associations between aPL, smoking and VE.

RESULTS

In multivariable-adjusted models ever, and in particular former, cigarette smoking was associated with the most pathogenic aPL; LA, aCL IgG and aβ2GP1 IgG. Other SLE-associated autoantibodies were not associated with smoking. The combination of smoking and aPL was strongly associated with VE. We noted a positive interaction between smoking-LA and smoking-'triple aPL' positivity for previous VE.

CONCLUSIONS

We investigated a large set of commonly occurring autoantibodies in SLE, but only aPL were positively associated with a history of smoking. This association was especially apparent in former smokers. Among ever regular smokers who were aPL positive, we observed a strikingly high frequency of former VE. The underlying mechanisms and temporality between smoking, aPL and VE need further investigations.

14th International Congress on Antiphospholipid Antibodies Task Force Report on Catastrophic Antiphospholipid Syndrome

The 'Task Force on Catastrophic Antiphospholipid Syndrome (CAPS)' was developed on the occasion of the 14th International Congress on Antiphospholipid Antibodies. The objectives of this Task Force were to assess the current knowledge on pathogenesis, clinical and laboratory features, diagnosis and classification, precipitating factors and treatment of this condition in order to address recommendations for future research. This article summarizes the studies analyzed by the Task Force, its recommendations and the future research agenda.

Infection-induced autoantibodies and pregnancy related pathology: an animal model

In addition to being the main cause of mortality worldwide, bacterial and viral infections can be the cause of autoimmune and pregnancy disorders as well. The production of autoantibodies during infection can be explained by various mechanisms, including molecular mimicry, bystander cell activation and epitope spreading. Conversely, bacterial and viral infections during pregnancy are especially dangerous for the fetus. It is documented that infection-induced inflammatory processes mediated by Toll-like receptors (TLR) represent the main cause of preterm labour. We used two crucial bacterial components and TLR ligands, namely peptidoglycan and lipopolysaccharide, to stimulate BALB/c mice before immunisation with tetanus toxoid. Tetanus toxoid is an inactive form of the toxin produced by bacterium Clostridium tetani and shares structural similarity with plasma protein β2-glycoprotein I. Treatment with peptidoglycan and lipopolysaccharide in combination with tetanus toxoid induced the production of pathological autoantibodies, different fluctuations in natural autoantibodies and different types of reproductive pathology in treated animals, with peptidoglycan treatment being more deleterious. We propose that the production of pathological autoantibodies, TLR activation and changes in natural autoantibodies play crucial roles in infection-induced reproductive pathology in our animal model.

Pathophysiology of the antiphospholipid antibody syndrome

Antiphospholipid antibodies (aPL) are associated with the recurrent pregnancy loss and thrombosis that characterizes the antiphospholipid antibody syndrome (APS). Although the ontogeny of these pathogenic antibodies has not been fully elucidated, there is evidence that indicates the involvement of both genetic and environmental factors. The ability of aPL to induce a procoagulant phenotype in APS patients plays a central role in the development of arterial and venous thrombotic manifestations typical of the disease. Inflammation serves as a necessary link between this procoagulant phenotype and actual thrombus development and is an important mediator of the placental injury seen in APS patients with obstetric complications. Recent evidence has indicated a role for abnormal cellular proliferation and differentiation in the pathophysiology of APS, especially in those patients with pregnancy morbidity and other more atypical manifestations that have no identifiable thrombotic cause. The interplay of genetic and environmental factors responsible for aPL development and the mechanisms by which these antibodies produce disease in APS patients is the focus of this review.

Induction of APS after TTd hyper-immunization has a different outcome in BALB/c and C57BL/6 mice

PROBLEM

The antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by vascular thrombosis and/or pregnancy complications (lower fecundity and lower litter size), as well as by an increase in anti-β(2) glycoprotein I (β(2) GPI)-specific autoantibody titer. We have investigated how the genetic background of the immune system [T helper (Th) prevalence] and the type of animal model of APS influence the induced pathology.

METHOD OF STUDY

Antiphospholipid syndrome induced by tetanus toxoid (TTd) hyper-immunization and by intravenous application of monoclonal anti-β(2) GPI-specific antibody 26 was compared in C57BL/6 (Th1 prone) and BALB/c (Th2 prone) mice.

RESULTS

Tetanus toxoid hyper-immunization of BALB/c mice led to reduction in fertility, but in C57BL/6 mice a decrease in fecundity occurred. In both cases, pathology was caused by anti-β(2) GPI antibodies, the production of which was adjuvant and strain dependent.

CONCLUSION

We conclude that TTd immunization and i.v. application of monoclonal antibody 26 induced the same reproductive pathology and that the type of pathology is strain dependent.

Common infectious agents prevalence in antiphospholipid syndrome

Antiphospholipid syndrome is characterized by thrombosis and pregnancy loss. Infections are generally associated with autoimmune diseases, but in the setting of antiphospholipid syndrome this link has been suggested as having a pathogenic role. In this study, 98 patients with antiphospholipid syndrome were screened for antibodies directed to several infectious agents. The main finding in this study is the significantly higher prevalence of IgM antibodies to toxoplasma and rubella. This novel finding suggests that these infections might be associated with antiphospholipid syndrome. As autoimmune diseases and, in particular, antiphospholipid syndrome are associated with infections, mainly the catastrophic type of the syndrome, this finding implies that a current infection with these agents, i.e. toxoplasma and rubella, might either be related to the pathogenesis of antiphospholipid syndrome or alternatively to its manifestations. Lupus (2009) 18, 1149—1153.

Antiphospholipid syndrome (APS): where does it come from?

The antiphospholipid syndrome (APS) is the most common acquired thrombophilia. It is characterized by venous and arterial thrombosis, recurrent pregnancy loss, and various other clinical manifestations in the presence of antiphospholipid antibodies (aPL). Like other autoimmune diseases, the etiology of APS derives from a combination of genetic and environmental factors. The most significant environmental factors in APS are infectious agents, followed by trauma and drugs. Infections can induce aPL and, in the catastrophic variant of APS, about one-third of cases are associated with a clear recent infection. On their formation, aPL have been clearly shown to be pathogenic, because they influence all arms of the coagulation system and because passive transfer and active immunization protocols have demonstrated. Therefore, in a genetically susceptible individual, exposure to one or more infectious agent can cause a molecular mimicry and result in the production of pathogenic aPL that can induce thrombosis and pregnancy loss. Identification of the epitopes within the beta-2-glycoprotein-I molecule that serves as the target for autoantibodies makes them the target for immunomodulation of the syndrome.