Antiphospholipid syndromes in infectious diseases

Antiphospholipid antibody-related hepatic vasculitis in a juvenile after non-severe COVID-19: a case report and literature review

Antiphospholipid antibodies (aPL) are both laboratory evidence and causative factors for a broad spectrum of clinical manifestations of antiphospholipid syndrome (APS), with thrombotic and obstetric events being the most prevalent. Despite the aPL-triggered vasculopathy nature of APS, vasculitic-like manifestations rarely exist in APS and mainly appear associated with other concurrent connective tissue diseases like systemic lupus erythematous. Several studies have characterized pulmonary capillaritis related to pathogenic aPL, suggesting vasculitis as a potential associated non-thrombotic manifestation. Here, we describe a 15-year-old girl who develops hepatic infarction in the presence of highly positive aPL, temporally related to prior non-severe COVID-19 infection. aPL-related hepatic vasculitis, which has not been reported before, contributes to liver ischemic necrosis. Immunosuppression therapy brings about favorable outcomes. Our case together with retrieved literature provides supportive evidence for aPL-related vasculitis, extending the spectrum of vascular changes raised by pathogenic aPL. Differentiation between thrombotic and vasculitic forms of vascular lesions is essential for appropriate therapeutic decision to include additional immunosuppression therapy. We also perform a systematic review to characterize the prevalence and clinical features of new-onset APS and APS relapses after COVID-19 for the first time, indicating the pathogenicity of aPL in a subset of COVID-19 patients.

The impact of antiphospholipid antibodies in Takayasu arteritis

BACKGROUND

The significance of antiphospholipid antibodies (aPL) is controversial in Takayasu arteritis (TA). This study was conducted to explore the frequency of aPL and their association with disease-related complications in TA.

METHODS

: This cross-sectional study was conducted to investigate the presence of anti-cardiolipin (aCL), anti-beta 2 glycoprotein- 1(aβ2G1) antibodies, and lupus anticoagulant (LA) in TA patients. TA patients admitted to the Department of Rheumatology of Hacettepe University Faculty of Medicine between December 2015 and September 2016 who fulfilled the American College of Rheumatology (ACR) classification criteria for TA were consecutively enrolled in the study. Patients were grouped according to aPL positivity and compared in terms of disease manifestations, type of vascular involvement at diagnosis, and vascular complications/interventions attributable to TA.

RESULTS

Fifty-three TA (49 female) patients were enrolled in the study. We detected 9 (16.9%) patients with IgM and/or IgG aβ2G1 and/or LA positivity. There were no patients with positive aCL. All aβ2G1 titers were low. There were no differences in terms of symptoms, signs, type of vascular involvement, the number of patients with disease-related complications or vascular interventions/surgery between aPL (+) and aPL(-) groups (p > 0.05 for all). The number of patients with thrombotic lesions was similar between the groups (p > 0.05). There were no patients with a history of venous thrombosis or on anticoagulant treatment in the aPL(+) group. Only 1 patient with IgM aβ2G1 (+) had a history of pregnancy loss.

DISCUSSION

Our results indicate that aPL positivity is not rare in TA. On the other hand, all aPL titers were low and no differences were found in the frequency of disease-related complications between aPL(+) and aPL(-) patient groups. Only TA patients with atypical manifestations with high suspicion of aPL-related complications should be considered to be investigated for aPL.

Dysregulation of immunity in COVID-19 and SLE

The immune response plays a crucial role in preventing diseases, such as infections. There are two types of immune responses, specific and innate immunity, each of which consists of two components: cellular immunity and humoral immunity. Dysfunction in any immune system component increases the risk of developing certain diseases. Systemic lupus erythematosus (SLE), an autoimmune disease in the human body, develops an immune response against its own components. In these patients, due to underlying immune system disorders and receipt of immunosuppressive drugs, the susceptibility to infections is higher than in the general population and is the single largest cause of mortality in this group. COVID-19 infection, which first appeared in late 2019, has caused several concerns in patients with SLE. However, there is no strong proof of additional risk of developing COVID-19 in patients with SLE, and in some cases, studies have shown less severity of the disease in these individuals. This review paper discusses the immune disorders in SLE and COVID-19.

Anti-phospholipid syndrome and COVID-19 thrombosis: connecting the dots

As the coronavirus disease 2019 (COVID-19) pandemic, which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is spreading rapidly worldwide, it has emerged as a leading cause of mortality, resulting in >1 million deaths over the past 10 months. The pathophysiology of COVID-19 remains unclear, posing a great challenge to the medical management of patients. Recent studies have reported an unusually high prevalence of thromboembolic events in COVID-19 patients, although the mechanism remains elusive. Several studies have reported the presence of aPLs in COVID-19 patients. We have noticed similarities between COVID-19 and APS, which is an autoimmune prothrombotic disease that is often associated with an infective aetiology. Molecular mimicry and endothelial dysfunction could plausibly explain the mechanism of thrombogenesis in acquired APS. In this review, we discuss the clinicopathological similarities between COVID-19 and APS, and the potential role of therapeutic targets based on the anti-phospholipid model for COVID-19 disease.

Anti-phospholipid syndrome in seven leprosy patients with thrombotic events on corticosteroid and/or thalidomide regimen: insights on genetic and laboratory profiles

INTRODUCTION

Corticosteroids and/or thalidomides have been associated with thromboembolism events (TBE) in multibacillary (MB) leprosy. This report aimed to determine genetic and laboratory profiles associated with leprosy and TBE.

METHODS

Antiphospholipid antibodies (aPL), coagulation-related exams, prothrombin and Leiden's factor V mutations, and ß2-glycoprotein-I (ß2GPI) Val247Leu polymorphism were assessed.

RESULTS

Six out of seven patients with leprosy were treated with prednisone and/or thalidomide during TBE and presented at least one positive aPL. All patients presented ß2GPI polymorphism, and one showed prothrombin mutation.

CONCLUSIONS

Corticosteroid or thalidomide adverse effects and aPL and ß2GPI polymorphisms may cause TBE in patients with MB leprosy.

Immunological Tolerance, Pregnancy, and Preeclampsia: The Roles of Semen Microbes and the Father

Although it is widely considered, in many cases, to involve two separable stages (poor placentation followed by oxidative stress/inflammation), the precise originating causes of preeclampsia (PE) remain elusive. We have previously brought together some of the considerable evidence that a (dormant) microbial component is commonly a significant part of its etiology. However, apart from recognizing, consistent with this view, that the many inflammatory markers of PE are also increased in infection, we had little to say about immunity, whether innate or adaptive. In addition, we focused on the gut, oral and female urinary tract microbiomes as the main sources of the infection. We here marshall further evidence for an infectious component in PE, focusing on the immunological tolerance characteristic of pregnancy, and the well-established fact that increased exposure to the father's semen assists this immunological tolerance. As well as these benefits, however, semen is not sterile, microbial tolerance mechanisms may exist, and we also review the evidence that semen may be responsible for inoculating the developing conceptus (and maybe the placenta) with microbes, not all of which are benign. It is suggested that when they are not, this may be a significant cause of PE. A variety of epidemiological and other evidence is entirely consistent with this, not least correlations between semen infection, infertility and PE. Our view also leads to a series of other, testable predictions. Overall, we argue for a significant paternal role in the development of PE through microbial infection of the mother via insemination.

Systematic review of case reports of antiphospholipid syndrome following infection

OBJECTIVE

The objective of this study was to conduct a systematic review of case reports documenting the development of antiphospholipid syndrome or antiphospholipid syndrome-related features after an infection.

METHODS

We searched Medline, EMBASE, Web of Science, PubMed ePubs, and The Cochrane Library - CENTRAL through March 2015 without restrictions. Studies reporting cases of antiphospholipid syndrome or antiphospholipid syndrome-related features following an infection were included.

RESULTS

Two hundred and fifty-nine publications met inclusion criteria, reporting on 293 cases. Three different groups of patients were identified; group 1 included patients who fulfilled the criteria for definitive antiphospholipid syndrome (24.6%), group 2 included patients who developed transient antiphospholipid antibodies with thromboembolic phenomena (43.7%), and group 3 included patients who developed transient antiphospholipid antibodies without thromboembolic events (31.7%). The most common preceding infection was viral (55.6%). In cases that developed thromboembolic events Human immunodeficiency and Hepatitis C viruses were the most frequently reported. Parvovirus B19 was the most common in cases that developed antibodies without thromboembolic events. Hematological manifestations and peripheral thrombosis were the most common clinical manifestations. Positive anticardiolipin antibodies were the most frequent antibodies reported, primarily coexisting IgG and IgM isotypes. Few patients in groups 1 and 2 had persistent antiphospholipid antibodies for more than 6 months. Outcome was variable with some cases reporting persistent antiphospholipid syndrome features and others achieving complete resolution of clinical events.

CONCLUSIONS

Development of antiphospholipid antibodies with all traditional manifestations of antiphospholipid syndrome were observed after variety of infections, most frequently after chronic viral infections with Human immunodeficiency and Hepatitis C. The causal relationship between infection and antiphospholipid syndrome cannot be established, but the possible contribution of various infections in the pathogenesis of antiphospholipid syndrome need further longitudinal and controlled studies to establish the incidence, and better quantify the risk and the outcomes of antiphospholipid-related events after infection.

The role of the gut microbiota in the pathogenesis of antiphospholipid syndrome

Infectious triggers are associated with the induction of transient antiphospholipid antibodies. One therefore wonders if microbes that permanently colonize us play a role in the pathogenesis of antiphospholipid syndrome (APS). The microbiota represents the collection of all microorganisms colonizing humans and is necessary for normal host physiology. The microbiota, however, is a constant stress on the immune system, which is tasked with recognizing and eliminating pathogenic microbes while tolerating commensal populations. A growing body of literature supports a critical role for the commensal-immune axis in the development of autoimmunity against colonized barriers (e.g., gut or skin) and sterile organs (e.g., pancreas or joints). Whether these interactions affect the development and sustainment of autoreactive CD4(+) T cells and pathogenic autoantibodies in APS is unknown. This review provides an overview of the current understanding of the commensal-immune axis in autoimmunity with a focus on the potential relevance to APS. Additionally, we discuss emerging findings supporting the involvement of the gut microbiota in a spontaneous model of APS, the (NZW × BXSB)F1 hybrid, and formalize hypotheses to explain how interactions between the immune system and the microbiota may influence human APS etiopathogenesis.

Characterization of antiphospholipid antibodies in chronic hepatitis B infection

BACKGROUND

Many infections are associated with antiphospholipid antibodies (aPLs). The purpose of this study was to investigate the prevalence, persistence, clinical significance, and characteristics of aPLs in hepatitis B virus (HBV)-infected patients.

METHODS

This study included 143 patients with HBV infection and 32 healthy individuals as controls. The presence of anticardiolipin antibodies (aCL Ab), anti-β(2)-glycoprotein I antibodies (β(2)GPI Ab), and lupus anticoagulant (LA) was assessed.

RESULTS

The total prevalence of aPLs in HBV-infected patients was 12.6% (18 of 143). Of these 18 patients, 15 had low to medium titers of aCL Ab (10 with IgM, 4 with IgG, and 1 with both isotypes). β(2)GPI Ab and LA were detected in 3 (2.1%) and 2 (1.4%) patients with HBV infection, respectively. In follow-up specimens from 14 patients with elevated levels of aCL Ab or β(2)GPI Ab, 10 (71.4%) showed the persistent presence of aPLs. No clinical manifestations related to aPLs were identified.

CONCLUSION

In HBV-infected patients, the most frequently detected antiphospholipid antibodies were IgM aCL Ab, which have a weak association with the clinical manifestations of APS. Unlike the transient presence reported for other infection-associated aPLs, most aPLs were persistently detected over a 12-week period in patients with HBV infection.

Antiphospholipid antibodies in haemophilia patients with severe bleeding tendency: cause, consequence or a consequential cause?

The prevalence, cause and the impact of antiphospholipid antibodies (APAs) on the clinical severity in haemophilia patients is poorly studied. We studied 72 severe seronegative (negative for HIV, HBsAg, HCV) haemophilia patients for the presence of four common APAs. Twenty-six (36.1%) were positive for any one of the APAs studied of which eight were positive only for anticardiolipin antibodies, three for beta2 glycoprotein (beta2GP1), four for prothrombin (PT) and six for anti annexin antibodies. Remaining six patients showed multi-specific antibodies. Further, clinically severe haemophilia patients (n = 37) showed higher prevalence of APAs as compared with the clinically milder group (n = 35) suggesting that these antibodies do not contribute in alleviating the clinical severity in haemophilia patients as has been observed with other inherited thrombophilia markers. The study of in vitro thrombin generation showed a higher endogenous thrombin potential (ETP) i.e. almost normal, in case of beta2GP1-positive patients as compared with patients with other types of APAs. High prevalence of APAs in clinically severe haemophilia patients may be a consequence of continuing tissue damage in the clinically severe group; as in India, clotting factor concentrates cannot be used ad lib because of financial constraints. Higher thrombin-generating potential in case of patients positive for beta2GP1 did not seem to have any impact on the clinical severity of haemophilia patients.

Infections and the antiphospholipid syndrome

Currently, the origin of autoimmune diseases is considered to be multifactorial. Genetic predisposition, immune system malfunction or even backfire, hormonal regulation, and environmental factors, i.e. infections, all play important roles in the pathogenesis of autoimmune diseases such as the antiphospholipid syndrome (APS). New drugs and strategies aimed at preventing infections could further improve the outcome of APS and other autoimmune diseases.

Anticorpos anticardiolipinas em úlceras de perna

OBJETIVO: Verificar a prevalência de anticorpos anticardiolipinas IgG e IgM em pacientes com úlcera de perna e se os seus portadores podem ser identificados clinicamente. MÉTODOS: Estudaram-se 151 pacientes com úlcera de perna (81 venosas, 50 diabéticas e 20 arteriais) e 150 controles. Pesquisou-se, nos dois grupos, a presença de anticorpos anticardiolipina IgG e IgM pelo método de ELISA. No grupo úlcera foram coletados dados demográficos dos pacientes, de tamanho e número de úlceras e gravidade da dor medido por escala visual analógica. Os dados obtidos foram agrupados em tabelas de frequência e contingência. Adotou-se significância de 5%. RESULTADOS: Encontrou-se prevalência de anticorpos anticardiolipina de 7.2% (n=12) no grupo com úlceras e de 1.3% (n=2) no controle (p=0.01). Comparando-se a prevalência dos anticorpos anticardiolipina nos diferentes tipos de úlcera verificou-se aumento nas de origem venosa (p=0.02) e diabéticas (p=0.01), mas não nas arteriais (p=0.31) em relação à população controle. As úlceras de perna anticardiolipinas positivas não diferiram daquelas sem anticardiolipinas quanto a tamanho da ferida (p=0.6); gravidade da dor (p=0.67), número médio de úlceras (p=0.38), tempo de duração de doença (p= 0.59), gênero do paciente (p=0.98) e história de trombose prévia (p=0.69). CONCLUSÃO: Existe aumento de prevalência de anticorpos anticardiolipinas nos portadores de úlceras de perna venosas e diabéticas, mas não nas arteriais. As características clínicas das úlceras anticardiolipinas positivas não auxiliam na identificação desses pacientes.

The antiphospholipid syndrome and infections in a child with trisomy 21

The relationship between infections and antiphospholipid antibodies or antiphospholipid syndrome is an intriguing question. A two and a half year old child with trisomy 21, who suffered three severe episodes of thrombosis each taking place after an infection, is described here. As high titres of IgG anticardiolipin (ACL) antibodies was registered during the second and third episodes, the antiphospholipid syndrome was suspected. IgM as well as IgG and IgA ACL antibodies have been described at different titres in a wide variety of infections, although they are not usually associated with thrombosis. In this particular case the timing of events and their association with high IgG ACL antibody titres seemed to implicate infection in the pathogenesis of the antiphospholipid syndrome. It can be hypothesized that some infections not only "trigger" antiphospholipid antibody production, but--in genetically predisposed subjects--can induce the clinical manifestations of the antiphospholipid syndrome.