Pediatric antiphospholipid syndrome. Curr Rheumatol Rep. 2015;17:27. [PMID: 25854492 DOI: 10.1007/s11926-015-0504-5]

The clinical relevance of different antiphospholipid antibody profiles in pediatric rheumatology patients

BACKGROUND

The clinical relevance of different antiphospholipid antibody (aPL) profiles, including low level anticardiolipin (aCL) and anti-β2-glycoprotein-I (aβ2GPI) antibodies, is ill-defined in the pediatric population. Our purpose is to describe the demographic, clinical, and laboratory characteristics of aPL positive pediatric patients based on different aPL profiles.

FINDINGS

In this single center retrospective cohort study, based on the screening of our pediatric (age ≤ 18) rheumatology electronic medical records (2016-2022), we identified patients who had at least one "positive" aPL (lupus anticoagulant [LA], aCL IgG/M, or aβ2GPI IgG/M) result. Patients were grouped into high- (LA positive and/or aCL/aβ2GPI IgG/M > 40U [ELISA]) and low-risk (LA negative and aCL/aβ2GPI IgG/M 20-39U) aPL profiles; those with persistently positive aPL were descriptively analyzed for demographic and clinical characteristics. Of 57 included patients, 34 (59%) had initial high- and 23 (40%) had initial low-risk profiles. Based on subsequent aPL results available in 42/57 (74%) patients, 25/27 (93%) in the high-, and 7/15 (47%) in the low-risk groups remained still positive. Of these 32 patients with persistently positive aPL, moderate-to-large vessel or microvascular thrombosis occurred in nine (28%) patients with high-risk and in none with low-risk aPL profiles; non-thrombotic aPL-related manifestations were reported in 15 (47%) patients with persistent aPL positivity.

CONCLUSION

An initial high-risk aPL profile was persistent in approximately 90% of our cohort, a third of whom had thrombosis, and half had non-thrombotic aPL manifestations. Our results underscore the need for a large-scale effort to better characterize aPL-related manifestations in pediatric patients with persistent high-risk aPL-profiles.

Pediatric antiphospholipid syndrome: clinical features and therapeutic interventions in a single center retrospective case series

BACKGROUND/PURPOSE

Pediatric antiphospholipid syndrome (APS) is a thromboinflammatory disease characterized by the presence of circulating antiphospholipid antibodies and either thrombotic events or pregnancy morbidity. The objective of this study was to review a large institution's experience to better understand the characteristics of children with APS.

METHODS

We conducted a retrospective review of pediatric APS at a tertiary referral center. The electronic medical record system was queried from 2000 through 2019, and 21 cases were included based on meeting the revised Sapporo Classification criteria by age 18 or younger. Comparisons between primary and secondary APS patients were made with two-tailed t-tests.

RESULTS

Twenty-one patients were included with a median age at diagnosis of 16 years and median follow-up of 5.8 years. Secondary APS was slightly more common than primary APS (11 vs. 10 cases) and was primarily diagnosed in the context of systemic lupus erythematosus. Two thirds of patients (67%) also had "non-criteria" manifestations of APS including thrombocytopenia, autoimmune hemolytic anemia, and livedo reticularis/racemosa. Almost half of patients (43%) had recurrent thrombosis, typically when patients were subtherapeutic or non-adherent with anticoagulation. Damage Index in Patients with Thrombotic APS (DIAPS) scores indicated a chronic burden of disease in both primary and secondary APS patients.

CONCLUSION

This case series of pediatric APS provides important context regarding disease phenotypes displayed by children with APS. High prevalence of non-criteria clinical manifestations highlights the need to consider these characteristics when developing pediatric-specific classification criteria and when considering this relatively rare diagnosis in pediatric practice.

Primary antiphospholipid syndrome in pediatrics: beyond thrombosis. Report of 32 cases and review of the evidence

OBJECTIVE

Describe the frequency of thrombotic and non-thrombotic clinical manifestations, laboratory, treatment and prognosis in patients with pediatric primary antiphospholipid syndrome.

MATERIAL AND METHODS

A retrospective study was carried out in patients with a diagnosis of primary antiphospholipid antibody syndrome, under 16 years of age, under follow-up by the pediatric rheumatology service of the General Hospital, National Medical Center, La Raza, from January 2013 to December 2020. The antiphospholipid syndrome was defined when it met the laboratory criteria of the Sidney criteria and the presence of thrombosis or non-criteria manifestations of the disease (hematological, neurological, cutaneous, renal, cardiac or pulmonary). Demographic, clinical, laboratory, treatment, and prognosis data were collected.

RESULTS

We report 32 patients, 21 female (65%) and 11 male (35%), mean age 11.75 years, evolution time 16 weeks. Thrombosis 9 patients (28%), 1 arterial and 8 venous. Non-thrombotic manifestations; Hematologic: thrombocytopenia 22 patients (69%), autoimmune hemolytic anemia 13 (40%), Fisher-Evans syndrome 6 (19%), lupus anticoagulant with hypoprothrombinemia syndrome 2 (6%). Dermatological: livedo reticularis 20 (62%), skin ulcers 2 (6%), Raynaud's phenomenon 8 (25%). Neurological: epilepsy 1 (3%), migraine 3 (9%), chorea 1 (3%) and cognitive impairment 3 (9%). Renal in 4 (13%). Laboratory: prolonged aPTT 30 (93%), lupus anticoagulant 32 (100%), positive IgG anticardiolipin 20 (62%), positive IgM anticardiolipin 19 (60%). AntiB2GPI was performed in only 3 patients, being positive in all.

TREATMENT

anticoagulation in patients with thrombosis, antiplatelet in 23 (72%), steroid 30 (94%), immunosuppressant 30 (94%) and rituximab 4 (12.5%). No deaths were reported.

CONCLUSIONS

The clinical characteristics of patients with pediatric primary antiphospholipid syndrome differ from those presented in adults, since non-thrombotic manifestations are more frequent in children, for which classification criteria that include these manifestations are necessary for a better characterization of the disease in pediatric population.

Managing Antiphospholipid Syndrome in Children and Adolescents: Current and Future Prospects

Pediatric antiphospholipid syndrome (APS) is a rare acquired multisystem autoimmune thromboinflammatory condition characterized by thrombotic and non-thrombotic clinical manifestations. APS in children and adolescents typically presents with large-vessel thrombosis, thrombotic microangiopathy, and, rarely, obstetric morbidity. Non-thrombotic clinical manifestations are frequently seen in pediatric APS and may be present even before the vascular thrombotic events occur. We review insights into the pathogenesis of APS and discuss potential targets for therapy. The identification of multiple immunologic abnormalities in patients with APS reveals molecular targets for current or future treatment. Management strategies, especially for APS in adolescents, require screening for additional prothrombotic risk factors and consideration of counseling regarding contraceptive strategies, lifestyle recommendations, treatment adherence, and mental health issues associated with this autoimmune thrombophilia. The main goal of therapy in pediatric APS is the prevention of thrombosis. The management of acute thrombosis events in children and adolescents is the same as for primary APS, which involves isolated occurrences, and secondary APS, which is seen in association with another autoimmune disease, e.g., systemic lupus erythematosus. A pediatric hematologist should be consulted so other differential thrombophilic conditions can be eliminated. Therapy includes unfractionated heparin or low-molecular-weight heparin followed by vitamin K antagonists. Treatment of catastrophic APS involves triple therapy (anticoagulation, intravenous corticosteroid pulse therapy, and plasma exchange) and may include intravenous immunoglobulin for children and adolescents with this condition. New drugs such as eculizumab and sirolimus seem to be promising drugs for APS.

Lupus anticoagulant in children – a confounding factor in diagnosis and targeted therapy

Introduction: Lupus anticoagulant (LAC) belongs to a heterogeneous group of antibodies directed against negatively charged phospholipid-binding proteins, inhibiting phospholipid-dependent reactions. We assessed the frequency, etiological background, clinical and biological expression as well as the appropriate management and outcome of LAC in a pediatric population.

Patients and methods: We included 19 pediatric patients diagnosed with a positive LAC test during a period of 1 year. LAC detection was carried out according to the ISTH/SCC guidelines 2012. Coagulometric assays were performed in order to check for coagulation factor activities. The presence of specific inhibitors has been tested by the Bethesda assay.

Results: LAC was positive in 0.4% of the patients monitored for increased activated partial thromboplastin time (aPTT) during the study period of 1 year. In contrast to the asymptomatic clinical image presented by the majority of our patients, the biological picture was dominated by an elevated aPTT (79 %), the aPTT ratio correlating significantly with the strength of LAC. In 58 % of the patients LAC became negative within 12 weeks, in another 4 (21%) patients within 20 weeks, whereas in 4 (21%) patients LAC remained positive throughout the follow-up.

Conclusion: Albeit usually innocent in asymptomatic patients, LAC needs to be seriously taken into consideration from the diagnostic point of view in order to avoid dangerous therapeutic attitudes..

Identifying additional risk factors for arterial and venous thrombosis among pediatric antiphospholipid antibodies carriers

BACKGROUND

Antiphospholipid antibodies (aPL) have been extensively reported in children, but investigations into thrombotic risks associated with aPL positivity in pediatric patients is scarce. Positive aPL are not uncommon in pediatric connective tissue diseases (CTD), but identification and management of these patients is challenging due to lack of validated criteria and a paucity of data. In this study, we identify potential additional risk factors for thrombosis in a unique cohort of pediatric aPL positive carriers.

METHODS

Retrospective chart review was performed on 491 pediatric patients with CTD seen in our institution from 2001 to 2019. Patients without persistently moderate to high titer aPL at least 12 weeks apart were excluded. Univariate analysis was performed to evaluate correlation between different risk factors and thrombotic events.

RESULTS

Seventy-one aPL positive children with underlying CTD are included in this cohort. The majority (87%) are female and of Hispanic ethnicity (56%). Mean age of the cohort at the diagnosis of connective tissue disease is 12.7 (SD 2.6) years, and mean age of first positive aPL is 13.3 (SD 2.5) years. Average length of follow-up is 4.3 (SD 2.5) years. Four (5.6%) patients experienced arterial thrombosis, and 11 (15.5%) had venous thrombosis. Fifty-seven (80.3%) patients did not have any thromboembolic events. Among traditional risk factors and signs of endothelial injury, only Raynaud's phenomena demonstrated significant association with arterial thrombosis (OR = 8.4, 95%CI 1.13-111, P = 0.039), and hypertension or anti-hypertensive use demonstrated significant association with venous thrombosis (OR = 8.387, 95%CI 1.2 - 94, P = 0.02).

CONCLUSION

Data from our cohort suggest that Raynaud's phenomenon is a potential predictor of arterial thrombosis while the presence of hypertension or anti-hypertensive medication use is a potential predictor of venous thrombosis in aPL positive pediatric carriers. Further studies investigating pediatric aPL profiles and risk factors for development of thrombosis are needed to help guide clinicians in caring for these challenging patients.

Pediatric Antiphospholipid Syndrome: from Pathogenesis to Clinical Management

PURPOSE OF REVIEW

Elucidating the pathogenic mechanisms mediated by antiphospholipid antibodies (aPL) might exert important clinical implications in pediatric antiphospholipid syndrome (APS).

RECENT FINDINGS

aPL are traditionally regarded as the main pathogenic players in APS, inducing thrombosis via the interaction with fluid-phase and cellular components of coagulation. Recent APS research has focused on the role of β2 glycoprotein I, which bridges innate immunity and coagulation. In pediatric populations, aPL should be screened in appropriate clinical settings, such as thrombosis, multiple-organ dysfunction, or concomitant systemic autoimmune diseases. Children positive for aPL tests often present non-thrombotic non-criteria manifestations or asymptomatic aPL positivity. In utero aPL exposure has been suggested to result in developmental disabilities, warranting long-term follow-up. The knowledge of the multifaceted nature of pediatric APS should be implemented to reduce the risk of underdiagnosing/undertreating this condition. Hopefully, recent pathogenic insights will open new windows of opportunity in the management of pediatric APS.

Treatment of thrombotic antiphospholipid syndrome in adults and children

PURPOSE OF REVIEW

Antiphospholipid syndrome (APS), more common than once believed, is an autoimmune disease best known for its high risk of incident and recurrent thrombotic events. The approach to treatment potentially differs from treatment of thrombosis in the general population, and this article endeavors to review the latest updates on this topic.

RECENT FINDINGS

The epidemiology of APS is being increasingly elucidated by large population-based studies, with APS perhaps affecting as many as 1 in 2000 individuals. Vitamin K antagonists, aspirin, and heparinoids continue to have obvious roles in the management of patients with APS. There has recently been intensive study of direct oral anticoagulants in APS, with the most recent randomized studies raising concerns about their inferiority to vitamin K antagonists, at least in some subgroups. Other approaches to treating APS beyond anticoagulants and antiaggregants are also receiving increased attention in mechanistic and preclinical studies with an eye toward future roles in patients with refractory and/or microvascular disease. Pediatric APS is identified as an area in desperate need of additional prospective research.

SUMMARY

Progress continues to be made in pursuit of improving the lives of individuals afflicted with APS. The most important future directions would seem to involve leveraging modern molecular technologies in order to improve subphenotyping of antiphospholipid antibody-positive individuals. This will help personalize risk profiles and ideally define the optimal approach to therapy based on future risk, rather than past morbid events.

Antiphospholipid syndrome and its role in pediatric cerebrovascular diseases: A literature review

Antiphospholipid syndrome (APS) or Hughes syndrome is an acquired thromboinflammatory disorder. Clinical criteria of APS diagnosis are large- and small-vessel thrombosis as well as obstetric problems; laboratory criteria are the presence of antiphospholipid antibodies (lupus anticoagulant, anticardiolipin antibodies and anti-β2-glycoprotein-1). The presence of at least 1 clinical and 1 laboratory criterion allows definitive diagnosis of APS. Primary APS is diagnosed in patients without features of connective tissue disease; secondary APS is diagnosed in patients with clinical signs of autoimmune disease. A high frequency of catastrophic APS as well as a high tendency to evolve from primary APS to secondary syndrome during the course of lupus and lupus-like disease is a feature of pediatric APS. The most characteristic clinical presentation of APS in the pediatric population is venous thrombosis, mainly in the lower limbs, and arterial thrombosis causing ischemic brain stroke. Currently, no diagnostic criteria for pediatric APS exist, which probably results in an underestimation of the problem. Similarly, no therapeutic procedures for APS specific for children have yet been established. In the present literature review, we discussed data concerning APS in children and its role in cerebrovascular diseases, including pediatric arterial ischemic stroke, migraine and cerebral venous thrombosis.

Pediatric Motor Inflammatory Neuropathy: The Role of Antiphospholipid Antibodies

We report the clinical case of a nine-year-old girl who presented with progressive motor neuropathy, revealed via the detection of a higher delay in F-wave recording using digitalized nerve conduction/electromyography. Since the lupus anticoagulant (LAC) positivity, detected using diluted Russell viper venom time (dRVVT), switched to persistent serological anticardiolipin immunoglobulin G (IgG) positivity, a possible non-thrombotic antiphospholipid antibody (aPL)-related clinical manifestation was suspected, and intravenous immunoglobulin treatment (IVIG) was started. The IVIG treatment was well tolerated and the complete resolution of motor impairment was obtained after the third IVIG infusion. Our findings suggest that it could be useful to check for antiphospholipid antibodies in children with a rapid onset of progressive neurological signs in order to provide the beneficial use of IVIG in the treatment of pediatric aPL neurological conditions.

Pediatric APS: State of the Art

PURPOSE OF REVIEW

The purpose of this report is to review recent research findings on APS in children and neonates.

RECENT FINDINGS

European evidence-based recommendations for diagnosis and treatment of pediatric APS has recently been published by the SHARE Initiative. Recent studies have shown a high prevalence of non-thrombotic manifestations in children with aPL, domains 4/5 specificity of 'innocent' anti-β2GPI antibodies in infants, and a higher risk for developmental delays and learning disabilities, hence, the need for neurodevelopmental monitoring in children born to mothers with APS. An International effort on creating a new diagnostic criteria for APS is underway. Pediatric APS is a rare disease with significant differences from the APS in adults. Majority of the children with persistently positive aPL do not develop thrombotic events; however, relatively higher proportion of thrombosis in children is related to aPL positivity compared to adults; this may partly be due to the absence of common pro-thrombotic "second-hit" risk factors of adults such as atherosclerosis and cigarette smoking. Diagnosis of APS in children may be delayed or missed when adult APS criteria are used, because in pediatric APS, non-thrombotic clinical manifestations such as thrombocytopenia, hemolytic anemia, and neurological disorders such as migraine, epilepsy, and chorea may precede thrombotic manifestations. Around 20% of the children initially diagnosed with primary APS eventually develop SLE. Neonatal APS is rare; however, the offspring of mothers with APS are at a higher risk for developmental delays and learning disabilities; prematurity and IUGR may increase this risk. Regular assessment of neurodevelopmental status of these children should be performed. Thrombosis is a rare event in the offspring of mothers with APS; anticoagulation of such infants is not recommended. An international effort to create a new diagnostic criteria for APS is underway.

Pediatric antiphospholipid syndrome

Despite its potential to cause significant morbidity in children, pediatric antiphospholipid syndrome (APS) is an understudied condition. In this review, we will cover what is known about pediatric APS epidemiology and how the clinician might approach the diagnosis of pediatric APS. We will highlight similarities and differences with the adult disease, both for primary APS and in the context of lupus. Clinical manifestations beyond thrombosis, especially neurologic and hematologic in nature, will be discussed. We will also consider what unique implications antiphospholipid antibody-positivity may have for children with lupus and for neonates born to mothers with APS. The approach to treatment will be covered, including the unique impact of APS medications on children as compared with adults. Finally, the importance of future mechanistic research is emphasized as physicians endeavor to provide the personalized care that children with APS clearly deserve.

Thrombosis in Children: Approach to Anatomic Risks, Thrombophilia, Prevention, and Treatment

Pediatric venous thromboembolism (VTE) is increasing in incidence but minimal data exist for best practices regarding therapy, use of thrombophilia testing, and management of long-term complications. Classification schema use anatomic location and presence of clinical or thrombophilic inciting factors. There are a small number of risk-assessment and risk-modeling systems for incident VTE, but all suffer from low numbers, single-institution design, and lack of prospective validation. Acute treatment is limited to heparin products and thrombolysis may be indicated in specific situations. In addition, chronic postthrombotic comorbidities are expected to increase in incidence and lack evidence-based treatment paradigms.

Lupus anticoagulant hypoprothrombinemia syndrome associated with systemic lupus erythematosus in children: report of two cases and systematic review of the literature

We report two children with systemic lupus erythematosus (SLE) having severe bleeding manifestations and lupus anticoagulant hypoprothrombinemia syndrome (LAHPS) along with a review of published cases of childhood SLE and LAHPS. We report clinical and laboratory profile of two children diagnosed with childhood SLE and LAHPS. We also conducted literature search to identify similar published cases and a review was performed. An 8-year-old girl had presented with fever, arthralgia, alopecia, anasarca and bleeding from multiple sites. She was diagnosed to have SLE based on laboratory investigations which showed anemia, thrombocytopenia, low complements, positive anti-nuclear antibody (ANA) and double standard DNA (dsDNA) antibodies. She was also found to have prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT), positive lupus anticoagulant (LA) and low factor II levels. She was diagnosed to have SLE with LAHPS and treated with intravenous methylprednisolone, intravenous immunoglobulin and cyclophosphamide with good outcome. Patient 2 was a 7-year-old-boy who was diagnosed to have SLE when he presented with fever, anasarca, malar rash, arthritis and bleeding from skin and mucosa. Laboratory investigations revealed anemia, proteinuria, low complements, positive ANA and anti-dsDNA titre. Coagulation studies showed deranged PT and aPTT, positive LA and low factor II levels. He was diagnosed to have SLE with LAHPS and was treated with intravenous methylprednisolone and oral mycophenolate mofetil. Review of literature of cases with childhood SLE and LAHPS showed that there are 32 cases have been reported till date which have been summarized. LAHPS is an uncommonly identified cause of bleeding in patients with SLE and must be suspected while evaluating these children.

The Differences Between Childhood and Adult Onset Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a rare autoimmune disease of unknown etiology that represents a leading cause of acquired thromboembolism and recurrent miscarriage. It is characterized by the persistent elevated presence of pathogenic antiphospholipid auto-antibodies directed against cardiolipin, ß2-glycoprotein-I, and/or a positive lupus anticoagulant test. As with many autoimmune disorders, the pathogenesis of APS is believed to be the result of a complex interaction between environmental triggers and genetic predisposition. Although more common in adults, APS occasionally manifests in the neonatal period and throughout childhood. Adut-onset APS classification criteria are poorly validated to the pediatric population (in which pregnancy related complications are seldom seen) and as a result, assessment of the prevalence of the disease in childhood is difficult. Thromboembolic events seen in children include deep venous thrombosis in addition to stroke and pulmonary embolism, which can lead to significant long-term disability. The disease can be classified as either primary (when occurring in isolation) or secondary, in which the disease is diagnosed in the context of another underlying disease, most commonly systemic lupus erythematosus. A variety of laboratory and clinical difference are seen between pediatric and adult-onset APS. The marked female predominance seen in adult-onset disease is less evident in childhood where the gender split is more evenly spread. In addition, children with APS are at a higher risk of recurrent thromboembolism than adults. The treatment of childhood-onset APS is challenging due to a lack of large-scale prospective studies in the pediatric population. Therapeutic options are often based upon treatment guidelines that have been based upon literature from the adult-onset form of the disease. In the majority of cases, treatment is focused on the prevention of further thrombosis through treatment with long-term anti-coagulation therapy. The evidence for the use of antiplatelet agents (such as aspirin) and hydroxychloroquine is inconclusive. It is important to remember that anti-coagulation can have significant lifestyle implications for the child with APS and it is essential to consider potential implications relating to school and recreational activities, with contact sports often discouraged due to the increased risk of bleeding.

What is known about pediatric antiphospholipid syndrome?

INTRODUCTION

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by vascular thrombosis and/or pregnancy morbidity associated with the persistent presence of antiphospholipid antibodies (aPL) including lupus anticoagulant (LA), anticardiolipin antibodies (aCL), and anti-β2 glycoprotein I antibodies (aβ2GPI).

AREAS COVERED

APS is considered as the most common acquired hypercoagulation state of autoimmune origin in children. Unfortunately, data about incidence, prevalence, thrombosis risk and effective treatment in paediatric APS are limited and unmethodical. Expert commentary: This review summarizes recent clinical, laboratory and therapy characterization of paediatric APS and emphasizes the differences between paediatric and adult populations.

A retrospective review of pediatric antiphospholipid syndrome and thrombosis outcomes

: Pediatric antiphospholipid syndrome (APS) is characterized by vascular thromboses and multisystem involvement associated with persistently positive antiphospholipid antibodies testing. There is limited literature regarding risk factors for development of thrombosis and long-term thrombotic outcomes in pediatric APS. The objective of our study was to review our institutional experience with pediatric APS and thrombosis outcomes. We conducted a 20-year retrospective review to study the clinical features, management, and long-term outcomes of patients between ages 6 months and 18 years diagnosed with APS. Seventeen patients (7 female; 10 male), with median age at first thrombosis being 15.3 years (range: 0.63-17.98 years) were included. The median follow-up period was 4.3 years (range: 0.8-16.9 years). Venous thrombosis was noted in 11 patients (64.7%) with arterial events occurring in six patients (35.3%). Nine (53%) patients were noted to have primary APS. Recurrent and/or progressive thrombotic events occurred in 10 patients (58.8%), which is higher than reported literature. The median time for recurrence/progression was 1.4 years (range: 0.37-11.85 years). At the time of recurrence/progression, only two (20%) patients were at therapeutic levels of anticoagulation. The high recurrence rate with majority of patients not being on therapeutic levels of anticoagulation at the time of the event along with 60% of recurrent events occurring at least 1 year from first vascular event suggests the possible need for long-term anticoagulation. However, larger pediatric studies are required to assess the need for long-term/indefinite anticoagulation.

Diagnosis and treatment of antiphospholipid syndrome in childhood: A review

The antiphospholipid syndrome (APS) is a multisystem autoimmune disease characterized by recurrent fetal loss and thromboembolic events associated with the presence of elevated titres of antiphospholipid antibodies (aPL). The purpose of this review is to summarize what is currently known about the diagnosis and treatment of pediatric APS, to highlight key differences between APS presenting in adults versus children throughout, and to identify areas where future research is needed.

Infections and Systemic Lupus Erythematosus: Binding or Sparring Partners?

Extensive work on experimental animal models clearly demonstrates that infectious agents can break immunological tolerance to self-antigens and induce autoimmune disorders, mainly systemic lupus erythematosus (SLE). The establishment of a causative link between infections and autoimmunity has been largely studied in a host of clinical studies, proving the role of infectious agents in the induction, as well as in the progression or exacerbation of SLE. However, we are far from a plain understanding of microbial-host interactions in the pathogenesis of SLE. Much serological, molecular and geoepidemiological evidence supports the relationship of different environmental infectious triggers in the inception of SLE-related autoimmune phenomena with adjuvant effects. The promotion of autoimmune responses through bystander activation or epitope spreading via multiple inflammatory pathways has been confirmed in animal models. Different viruses have been implicated in SLE pathogenesis, particularly Epstein-Barr virus, but also parvovirus B19, cytomegalovirus and retroviruses. SLE patients usually have an impaired immune response towards Epstein-Barr virus and dysregulation of the viral latency period. Furthermore, the accumulation of endogenous retroviral products might trigger the production of interferon and anti-DNA antibodies. In addition, protozoan infections might even protect from autoimmune processes and rescind an ongoing B cell activation. Herein, we discuss which type of infections induce, exacerbate or inhibit autoimmune disorders and analyze the principal infection-induced immunological mechanisms influencing the development of SLE.