Vaccination and the risk of systemic lupus erythematosus: a meta-analysis of observational studies

OBJECTIVE

This meta-analysis aims to explore the potential link between vaccines and systemic lupus erythematosus (SLE).

METHODS

We systematically searched PubMed, Cochrane Library, and Embase for observational studies from inception to September 3, 2023, using medical subject headings (MeSH) and keywords. Study quality was assessed using the NOS scale. Statistical analyses were conducted using STATA software (version 14.0). Publication bias was evaluated using funnel plots and Egger's regression.

RESULTS

The meta-analysis incorporated 17 studies, encompassing 45,067,349 individuals with follow-up periods ranging from 0.5 to 2 years. The pooled analysis revealed no significant association between vaccinations and an increased risk of SLE [OR = 1.14, 95% CI (0.86-1.52), I2 = 78.1%, P = 0.348]. Subgroup analyses indicated that HBV vaccination was significantly associated with an elevated risk of SLE [OR =2.11, 95% CI (1.11-4.00), I2 = 63.3%, P = 0.02], HPV vaccination was slightly associated with an increased risk of SLE [OR = 1.43, 95% CI (0.88-2.31), I2 = 72.4%, P = 0.148], influenza vaccination showed no association with an increased risk of SLE [OR = 0.96, 95% CI (0.82-1.12), I2 = 0.0%, P = 0.559], and COVID-19 vaccine was marginally associated with a decreased risk of SLE [OR = 0.44, 95% CI (0.18-1.21), I2 = 91.3%, P = 0.118].

CONCLUSIONS

This study suggests that vaccinations are not linked to an increased risk of SLE. Our meta-analysis results provide valuable insights, alleviating concerns about SLE risk post-vaccination and supporting further vaccine development efforts.

Environmental risk factors of systemic lupus erythematosus: a case-control study

Systemic lupus erythematosus (SLE) is a complicated chronic autoimmune disorder. Several genetic and environmental factors were suggested to be implicated in its pathogenesis. The main objective of this study was to examine how exposure to selected environmental factors was associated with SLE risk to support the development of disease preventive strategies. A case-control study was conducted at the Rheumatology outpatient clinic of Alexandria Main University Hospital, in Alexandria, Egypt. The study sample consisted of 29 female SLE patients, and 27 healthy female controls, who matched the cases on age and parity. Data were collected by a structured interviewing questionnaire. Blood levels of lead, cadmium, and zinc of all participants were assessed by flame atomic absorption spectrometry. The multivariate stepwise logistic regression model revealed that five factors showed significant association with SLE, namely living near agricultural areas, passive smoking, blood lead levels ≥ 0.075 mg/L, and exposure to sunlight (odds ratio (OR) 58.556, 95% confidence interval (CI) 1.897-1807.759, OR 24.116, 95% CI 1.763-329.799, OR 18.981, 95% CI 1.228-293.364, OR 9.549, 95% CI 1.299-70.224, respectively). Whereas walking or doing exercise were significantly protective factors (P = 0.006). The findings of this study add to the evidence that SLE can be environmentally induced. Preventive measures should be taken to address the environmental risk factors of SLE.

Presentation of SLE after COVID vaccination in a pediatric patient

BACKGROUND

The outbreak of severe acute respiratory syndrome coronavirus 2 has had an enormous impact on global health. Vaccination remains one of the most effective interventions for disease prevention. Clinically significant vaccine side effects are uncommon, though autoimmune-mediated disease occurs in a small percentage of vaccine recipients. Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that is associated with significant morbidity and mortality. Childhood-onset SLE tends to have more severe disease manifestations than adult-onset SLE. In adults, there are a few reported cases of SLE developing soon after coronavirus disease 2019 (COVID-19) mRNA vaccination.

CASE PRESENTATION

A 14-year-old previously healthy male developed laboratory and clinical evidence of SLE, including maculopapular malar rash, arthritis, pleuritic chest pain, and class V (membranous) lupus nephritis, 2 days after his third dose of the Pfizer-BioNTech COVID-19 vaccine. The patient's symptoms improved after initiation of prednisone and mycophenolate mofetil. We also summarize eleven prior case reports describing SLE after COVID-19 vaccine in adults.

CONCLUSION

To our knowledge, this is the first reported pediatric patient with new onset SLE following COVID-19 mRNA vaccination. While potential mechanistic links exist between COVID-19 vaccination and SLE development, additional studies are necessary to elucidate the exact nature of this relationship.

Systemic Lupus Erythematosus Risk: The Role of Environmental Factors

Systemic lupus erythematosus (SLE) is a complex, chronic autoimmune disease. The etiology of SLE is multifactorial and includes potential environmental triggers, which may occur sequentially (the "multi-hit" hypothesis). This review focuses on SLE risk potentially associated with environmental factors including infections, the microbiome, diet, respirable exposures (eg, crystalline silica, smoking, air pollution), organic pollutants, heavy metals, and ultraviolet radiation.

Understanding the Concept of Pre-Clinical Autoimmunity: Prediction and Prevention of Systemic Lupus Erythematosus: Identifying Risk Factors and Developing Strategies Against Disease Development

There is growing evidence that preceding the diagnosis or classification of systemic lupus erythematosus (SLE), patients undergo a preclinical phase of disease where markers of inflammation and autoimmunity are already present. Not surprisingly then, even though SLE management has improved over the years, many patients will already have irreversible disease-related organ damage by time they have been diagnosed with SLE. By gaining a greater understanding of the pathogenesis of preclinical SLE, we can potentially identify patients earlier in the disease course who are at-risk of transitioning to full-blown SLE and implement preventative strategies. In this review, we discuss the current state of knowledge of SLE preclinical pathogenesis and propose a screening and preventative strategy that involves the use of promising biomarkers of early disease, modification of lifestyle and environmental risk factors, and initiation of preventative therapies, as examined in other autoimmune diseases such as rheumatoid arthritis and type 1 diabetes.

The role of environmental exposures and gene-environment interactions in the etiology of systemic lupus erythematous

Systemic lupus erythematosus (SLE) is a complex, chronic autoimmune disease, whose etiology includes both genetic and environmental factors. Individual genetic risk factors likely only account for about one-third of observed heritability among individuals with a family history of SLE. A large portion of the remaining risk may be attributable to environmental exposures and gene-environment interactions. This review focuses on SLE risk associated with environmental factors, ranging from chemical and physical environmental exposures to lifestyle behaviors, with the weight of evidence supporting positive associations between SLE and occupational exposure to crystalline silica, current smoking, and exogenous estrogens (e.g., oral contraceptives and postmenopausal hormones). Other risk factors may include lifestyle behaviors (e.g., dietary intake and sleep) and other exposures (e.g., ultraviolet [UV] radiation, air pollution, solvents, pesticides, vaccines and medications, and infections). Alcohol use may be associated with decreased SLE risk. We also describe the more limited body of knowledge on gene-environment interactions and SLE risk, including IL-10, ESR1, IL-33, ITGAM, and NAT2 and observed interactions with smoking, UV exposure, and alcohol. Understanding genetic and environmental risk factors for SLE, and how they may interact, can help to elucidate SLE pathogenesis and its clinical heterogeneity. Ultimately, this knowledge may facilitate the development of preventive interventions that address modifiable risk factors in susceptible individuals and vulnerable populations.

Lupus, vaccinations and COVID-19: What we know now

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the virus causing Coronavirus disease 2019 (COVID-19), has had a huge impact on health services, with a high mortality associated with complications including pneumonia and acute respiratory distress syndrome. Patients with systemic lupus erythematosus (SLE) are at increased risk of viral infections, and recent data suggests they may be at an increased risk of poor outcomes with COVID-19. This may be particularly true for those on rituximab or high dose steroids. A huge international effort from the scientific community has so far resulted in the temporary authorisation of three vaccines which offer protection against SARS-CoV-2, with over 30 other vaccines being evaluated in ongoing trials. Although there has historically been concern that vaccines may trigger disease flares of SLE, there is little convincing evidence to show this. In general lupus patients appear to gain good protection from vaccination, although there may be reduced efficacy in those with high disease activity or those on immunosuppressive therapies, such as rituximab or high dose steroids. Recent concerns have been raised regarding rare clotting events with the AstraZeneca/Oxford vaccine and it is currently unknown whether this risk is higher for those patients with secondary antiphospholipid syndrome. With the possibility of annual COVID vaccination programmes in the future, prospective data collection and registries looking at the effect of vaccination on SLE disease control, the incidence of COVID-19 in SLE patients and severity of COVID-19 disease course would all be useful. As mass vaccination programmes begin to roll out across the world, we assess the evidence of the use of vaccines in SLE patients and in particular vaccines targeting SARS-CoV-2.

Subacute cutaneous lupus erythematosus triggered after measles vaccination

Subacute cutaneous lupus erythematosus (SCLE) is a subtype of cutaneous lupus erythematosus that can be triggered by endogenous or exogenous factors. Among the exogenous factors are some medications, drugs, tobacco, infections, and vaccines. In this context, the benefits of vaccination are questioned because although it is important to prevent infections in immunosuppressed patients a theoretical risk of developing systemic lupus erythematosus (SLE) remains in these patients. This report presents a case of a previously healthy female patient who developed SCLE after measles vaccination and progressed to SLE and thereby suggests a possible trigger of the disease.

Update on the treatment and outcome of systemic lupus erythematous in children

PURPOSE OF REVIEW

Provide an update of studies published in last 2 years on the outcomes and therapies in childhood-onset systemic lupus erythematous (cSLE).

RECENT FINDINGS

Additional evidence has been provided about the benefits of universal hydroxychloroquine in SLE patients, although antimalarial maculopathy may be more prevalent than previously thought. Recent studies support lower glucocorticoid doses than used in the past may provide comparable therapeutic benefits, and cSLE patients can mount adequate immunogenic response and sustain long-term seroprotective titers when vaccinated. Long-term studies of adults with cSLE confirmed that damage accrual increases with disease duration. Cardiovascular disease, renal transplants, replacement arthroplasties, and myocardial infarctions occur between 20 and 40 years of age. Higher prednisone doses predicted higher damage trajectory and antimalarial exposure was protective. There were no prospective clinical trials published in pediatric patients with cSLE, but positive results from phase II trials with bariticinib and ustekinumab in adult SLE may raise the expectation that these drugs could be beneficial when used in cSLE.

SUMMARY

The dire need for more clinical trials and licensed medications for cSLE persist as well as decreasing damage accrual.

The systematic case-referent method

The systematic case-referent method is a special case-referent design originally developed for pharmacoepidemiologic research purposes. It consists in the systematic collection of series of incident cases of various disorders and the assembling of a general reference pool, from which "controls" are secondarily selected to be matched to specific cases. Both series are collected independently from each other and with no a priori hypothesis to be investigated. The reference pool can be either general or limited to a subpopulation, representative of the source population of the cases. Based on clinical recruitment of cases and referents, the design allows a very high specificity of diagnosis and documentation of clinical variables. All cases and referents are systematically documented on all treatments received before the incidence of the cases or before identification of referents. This documentation is done preferentially using objective sources assembled independently (linkage to claims data, medical records, pharmacy records, prescription records, hospital discharge letters). It can be completed with patients' interviews using standardised research tools, in particular for over-the-counter drug use and self-medication, and for the documentation of adherence to treatment and specific time-windows of exposure. Likewise, all cases and all referents are systematically documented on a series of risk factors, which are common to most epidemiological studies and are not hypothesis-dependent. Whenever the documentation of a confounding factor specific to the disease at hand is necessary, additional questionnaires can be applied to all or a sample of patients. The method has been successfully implemented for the pharmacoepidemiologic study of myocardial infarction, stroke, lupus, multiple sclerosis, rheumatoid arthritis, Guillain Barré syndrome, idiopathic thrombocytopenic purpura, type 1 diabetes mellitus, suicide attempts, breast cancer, and other disorders, for the analysis of the risk or preventing action of NSAIDs, statins, antiplatelet agents, anticoagulants, insulins, vaccines and other drugs.

Vaccination coverage in systemic lupus erythematosus-a cross-sectional analysis of the German long-term study (LuLa cohort)

Objectives

Vaccinations are an important measure to prevent infections in immunocompromised patients. The knowledge of vaccination coverage and reasons for non-vaccination in patients with SLE is scarce. The aim of this study was to assess coverage rates of selected vaccinations in a representative sample of SLE patients and to identify predictors for non-vaccination.

Methods

In 2013, information on selected vaccinations (coverage, application and reservations) and on demographics, clinical parameters and health beliefs was assessed by means of a self-reported questionnaire among a representative sample of SLE patients in Germany (LuLa cohort).

Results

Five hundred and seventy-nine patients participated. Vaccination status was primarily checked by their general practitioner (57.3%). Of all the patients, 24.9% did not get their vaccination status checked at all, 16.1% had generally been advised against the use of vaccinations by a physician, and 37.5% stated that they had rejected vaccinations themselves. Their main reasons were fears of developing a lupus flare (21.8%) or adverse events (13.5%). A greater belief by patients in the doctor controlling one's health and the general benefit of medication prevented the rejection of vaccines. Vaccination coverage was low for all recorded vaccinations (tetanus 65.8%, influenza 45.2%, pneumococcus 32.2% and meningococcus 6.1%). Older age was predictive of receiving influenza and pneumococcal vaccination. The same applies for CSs >7.5 mg for receiving influenza vaccination.

Conclusion

Vaccination coverage in SLE patients is poor and reflects insufficient implementation of national and international recommendations. Rheumatologists need to recognize patients' reservations against vaccinations, to communicate their importance and safety and to give individual recommendations to patients and their health-care providers.

Trial registration

German Clinical Trials Register, www.germanctr.de, DRKS00011052.

Pneumococcal vaccination in patients with systemic lupus erythematosus: A multicenter placebo-controlled randomized double-blind study

BACKGROUND

Invasive pneumococcal disease and respiratory tract infections are both frequent and severe in patients with systemic lupus erythematosus (SLE). This study aimed to compare the immunological efficacy and safety of pneumococcal vaccination with the 23-valent polysaccharide (PPS) vaccine alone to a sequential immunization with the 7-valent pneumococcal conjugate (PnCj) vaccine followed by PPS in patients with SLE and stable diseaase.

METHODS

Multicenter randomized placebo-controlled double-blind trial: PPS vaccine alone (placebo-PPS group) or PnCj vaccine followed by PPS vaccine (PnCj-PPS group) 24weeks later. The primary endpoint was the rate of responders at week 28 to at least 5 of the 7 serotypes (4, 6B, 9V, 14, 18C, 19F and 23F) shared by both PPS and PnCj. Pneumococcal IgG antibodies' opsonophagocytic activity (OPA) were also assessed.

RESULTS

Twenty-five patients in the placebo-PPS group and 17 in the PnCj-PPS group were included in a modified intention-to-treat analysis. The primary endpoint was reached in 72% (18/25) in the placebo-PPS and 76% (13/17) in the PnCj-PPS group (p=0.75). There was no difference in the rates of responders with OPA. At week 52, 13/18 (72%) patients in the placebo-PPS group and 10/13 (77%) patients in the PnCj-PPS group (p=0.77) that met the primary endpoint at week 28 were still responders to ≥5/7 serotypes shared by both PPS and PnCj vaccines. Nine SLE flares were reported in 6 patients (4 in the placebo-PPS and 2 in the PnCj-PPS groups respectively, p=0.70).

CONCLUSION

Sequential administration of PnCj vaccine followed by PPS vaccine is safe and shows short-term immunological efficacy in patients with SLE but was not superior to the PPS vaccine alone.

TRIAL REGISTRATION

www.clinicaltrials.gov, NCT NCT00611663.

Environmental exposures and the development of systemic lupus erythematosus

PURPOSE OF REVIEW

This review examines evidence relating environmental factors to the development of systemic lupus erythematosus (SLE).

RECENT FINDINGS

The strongest epidemiologic evidence exists for the associations of silica, cigarette smoking, oral contraceptives, postmenopausal hormone therapy and endometriosis, with SLE incidence. Recent studies have also provided robust evidence of the association between alcohol consumption and decreased SLE risk. There are preliminary, conflicting or unsubstantiated data that other factors, including air pollution, ultraviolet light, infections, vaccinations, solvents, pesticides and heavy metals such as mercury, are related to SLE risk. Biologic mechanisms linking environmental exposures and SLE risk include increased oxidative stress, systemic inflammation and inflammatory cytokine upregulation, and hormonal triggers, as well as epigenetic modifications resulting from exposure that could lead to SLE.

SUMMARY

Identifying the environmental risk factors related to risk of SLE is essential as it will lead to increased understanding of pathogenesis of this complex disease and will also make risk factor modification possible for those at increased risk.

Lack of evidence for post-vaccine onset of autoimmune/lymphoproliferative disorders, during a nine-month follow-up in multiply vaccinated Italian military personnel

Anecdotal case reports, amplified by mass media and internet-based opinion groups, have recently indicated vaccinations as possibly responsible for autoimmunity/lymphoproliferation development. Multiply vaccinated Italian military personnel (group 1, operating in Italy, group 2, operating in Lebanon) were followed-up for nine months to monitor possible post-vaccine autoimmunity/lymphoproliferation onset. No serious adverse event was noticed in both groups. Multivariate analysis of intergroup differences only showed a significant association between lymphocyte increase and tetanus/diphtheria vaccine administration. A significant post-vaccine decrease in autoantibody positivity was observed. Autoantibodies were also studied by microarray analysis of self-proteins in subjects exposed to ≥4 concurrent vaccinations, without observing significant difference among baseline and one and nine months post-vaccine. Moreover, HLA-A2 subjects have been analyzed for the possible CD8T-cell response to apoptotic self-epitopes, without observing significant difference between baseline and one month post-vaccine. Multiple vaccinations in young adults are safe and not associated to autoimmunity/lymphoproliferation onset during a nine-month-long follow-up.

Understanding the role of environmental factors in the development of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystem disease with a complex etiology. Its risk is higher among women, racial and ethnic minorities, and individuals with a family history of SLE or related autoimmune diseases. It is believed that genetic factors interact with environmental exposures throughout the lifespan to influence susceptibility to developing SLE. The strongest epidemiologic evidence exists for increased risk of SLE associated with exposure to crystalline silica, current cigarette smoking, use of oral contraceptives, and postmenopausal hormone replacement therapy, while there is an inverse association with alcohol use. Emerging research results suggest possible associations of SLE risk with exposure to solvents, residential and agricultural pesticides, heavy metals, and air pollution. Ultraviolet light, certain infections, and vaccinations have also been hypothesized to be related to SLE risk. Mechanisms linking environmental exposures and SLE include epigenetic modifications resulting from exposures, increased oxidative stress, systemic inflammation and inflammatory cytokine upregulation, and hormonal effects. Research needs to include new studies of environmental risk factors for SLE in general, with a focus on lifetime exposure assessment. In addition, studies in susceptible subgroups, such as family members, studies based on genetic risk profiles, and studies in individuals with evidence of pre-clinical autoimmunity based on the detection of specific auto-antibodies are also required. Understanding the role of environmental exposures in the development of SLE may help identify modifiable risk factors and potential etiological mechanisms.

Vaccinations and risk of systemic lupus erythematosus and rheumatoid arthritis: A systematic review and meta-analysis

BACKGROUND

In the past several years, more and more studies proposed some concerns on the possibly increased risk of autoimmune diseases in individuals receiving vaccinations, but published studies on the associations of vaccinations with risks of systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) reported conflicting findings. A systematic review and meta-analysis was carried out to comprehensively evaluate the relationship between vaccinations and risk of SLE and RA.

METHODS

Pubmed, Web of Science and Embase were searched for observational studies assessing the associations of vaccinations with risks of RA and SLE. Two authors independently extracted data from those eligible studies. The quality of eligible studies was assessed by using the Newcastle-Ottawa Scale (NOS). The pooled relative risk (RR) with 95% confidence intervals (CIs) was used to measure the risk of RA and SLE associated with vaccinations, and was calculated through random-effect meta-analysis.

RESULTS

Sixteen observational studies were finally considered eligible, including 12 studies on the association between vaccinations and SLE risk and 13 studies on the association between vaccinations and RA risk. The pooled findings suggested that vaccinations significantly increased risk of SLE (RR=1.50; 95%CI 1.05-2.12, P=0.02). In addition, there was an obvious association between vaccinations and increased risk of RA (RR=1.32; 95%CI 1.09-1.60, P=0.004). Meta-analysis of studies reporting outcomes of short vaccinated time also suggested that vaccinations could significantly increase risk of SLE (RR=1.93; 95%CI 1.07-3.48, P=0.028) and RA (RR=1.48; 95%CI 1.08-2.03, P=0.015). Sensitivity analyses in studies with low risk of bias also found obvious associations of vaccinations with increased risk of RA and SLE.

CONCLUSION

This study suggests that vaccinations are related to increased risks of SLE and RA. More and larger observational studies are needed to further verify the findings above and to assess the associations of vaccinations with other rheumatic diseases.

Infection in systemic lupus erythematosus, similarities, and differences with lupus flare

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with diverse manifestations, and its pathogenesis is unclear and complicated. Infection and SLE are similar in that they both cause inf lammatory reactions in the immune system; however, one functions to protect the body, whereas the other is activated to damage the body. Infection is known as one of the common trigger factors for SLE; there are a number of reports on infectious agents that provoke autoimmune response. Several viruses, bacteria, and protozoa were revealed to cause immune dysfunction by molecular mimicry, epitope spreading, and bystander activation. In contrast, certain pathogens were revealed to protect from immune dysregulation. Infection can be threatening to patients with SLE who have a compromised immune system, and it is regarded as one of the common causes of mortality in SLE. A clinical distinction between infection and lupus f lare up is required when patients with SLE present fevers. With a close-up assessment of symptoms and physical examination, C-reactive protein and disease activity markers play a major role in differentiating the different disease conditions. Vaccination is necessary because protection against infection is important in patients with SLE.

The safety and immunogenicity of Quadrivalent HPV (qHPV) vaccine in systemic lupus erythematosus

OBJECTIVE

This study evaluated the safety and immunogenicity of qHPV vaccine in SLE.

METHODS

Subjects: 34 women ages 19-50years (yrs.) with mild to moderate SLE & minimally active or inactive SLE received qHPV vaccine at the standard dosing schedule.

EXCLUSION CRITERIA

active SLE disease (SELENA-SLEDAI>2), history of severe SLE disease, deep venous thrombosis, on >400mg/day of hydroxychloroquine, on >15mg/day of prednisone, or active infections. Patients were monitored for adverse events (AE), SLE flare, generation of thrombogenic antibodies and thrombosis. Antibody (Ab) levels to HPV 6, 11, 16 & 18 were measured by HPV competitive Luminex Immunoassay and Geometric Mean Titers (GMTs) were calculated for each HPV type. Seroconversion was assessed for those seronegative at baseline.

RESULTS

The women in the study: African-American (79%), mean age=38.1years, mean age at diagnosis of SLE=28.6years, 35.3% had a history of smoking, 91% had 4 or more sexual partners, 50% had a history of sexually transmitted diseases, and 27.3% used condoms on a regular basis. Vaccine site reactions (VSRs) occurred in 62%, all mild. Ninety-seven percent experienced at least 1 non vaccine adverse event (nvAE) with a total of 493 nvAEs in 33 patients, of which 90% were mild and none were related to vaccine or SLE. There were 9 serious AEs, none were related to vaccine or SLE, all resolved. No patient experienced an SLE flare, thrombosis, or generation of thrombogenic antibodies. Seroconversion rate was 100% with mean GMTs comparable to Gardasil® package insert data.

CONCLUSION

In this SLE vaccine study, qHPV vaccine was generally safe, well tolerated, and highly immunogenic. This clinical trial is registered on Clinical Trials.gov under number, NCT01741012 and was conducted under the FDA IND BB14113.

Autoimmune disease and vaccination: impact on infectious disease prevention and a look at future applications

Vaccines hold promise both for the prevention of infections and as potential immunologic therapy for patients with autoimmune disease (AD). These patients are at high risk for both common and opportunistic infections, but this risk can be significantly reduced and even obviated with the use of recommended available vaccines. Unfortunately, patients with ADs are not routinely offered or provided indicated vaccinations and have higher rates of complications from vaccine-preventable illnesses than patients without ADs. In addition, vaccine therapy is currently under study for the treatment of autoimmune disorders, with early studies demonstrating immunomodulatory effects that may counter undesired immune activation and alleviate disease activity.

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.

Update on infections and vaccinations in systemic lupus erythematosus and Sjögren's syndrome

PURPOSE OF REVIEW

To provide an update on infections in systemic lupus erythematosus (SLE) and Sjögren's syndrome, particularly addressing their role as triggers of autoimmunity, their impact on mortality, the main microorganisms, the approaches to differential diagnosis with disease flares and recommendations for vaccination.

RECENT FINDINGS

New mechanisms for autoimmunity triggered by Epstein-Barr virus and human commensal microbiota have been described. The increased risk for tuberculosis was recently demonstrated for the first time in Sjögren's syndrome. C-reactive protein was reported to be a more sensitive and specific marker for bacterial infections in SLE than procalcitonin and phagocyte-specific S100A8/A9 protein. Inactivated vaccines are well tolerated and efficacy was demonstrated for influenza vaccine. Immunogenicity is generally reduced but adequate in SLE. Prednisone or immunosuppressants are associated with decreased vaccine serological response, whereas hydroxicloroquine seems to improve vaccine immunogenicity. Other infection-preventive measures for these diseases include antimalarials and prophylaxis for tuberculosis or Pneumocystis jirovecii.

SUMMARY

Advances in the role of infectious agents as triggers for SLE and Sjögren's syndrome have provided new insights into disease development. Knowledge on vaccine immunogenicity, safety and efficacy has improved with evidence of a generally reduced but adequate response for inactivated vaccines in SLE. Other preventive measures comprise infection prophylaxis and antimalarials.

Vaccination of patients with autoimmune inflammatory rheumatic diseases

Patients with autoimmune inflammatory rheumatic diseases (AIRDs) are at increased risk of infections. This risk has been further increased by the introduction of biologic agents over the past two decades. One of the most effective strategies to prevent infection is vaccination. However, patients with an AIRD have a compromised immune system, which is further impaired by medication. Another important issue is the possibility of triggering a broad nonspecific response by vaccination, potentially resulting in increased activity of the underlying autoimmune disease. In this Review, we provide an analysis of data on vaccination of patients with an AIRD. Both the efficacy and the safety of vaccination are addressed, together with the epidemiology of vaccine-preventable infectious diseases in different subgroups of adults with AIRDs. Special attention is given to vaccination of patients who are treated with biologic agents.

Environmental factors, toxicants and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an immune-complex-mediated multi-systemic autoimmune condition of multifactorial etiology, which mainly affects young women. It is currently believed that the onset of SLE and lupus flares are triggered by various environmental factors in genetically susceptible individuals. Various environmental agents and toxicants, such as cigarette smoke, alcohol, occupationally- and non-occupationally-related chemicals, ultraviolet light, infections, sex hormones and certain medications and vaccines, have been implicated to induce SLE onset or flares in a number case series, case-control and population-based cohort studies and very few randomized controlled trials. Here, we will describe some of these recognized environmental lupus triggering and perpetuating factors and explain how these factors potentially bias the immune system towards autoimmunity through their interactions with genetic and epigenetic alterations. Further in-depth exploration of how potentially important environmental factors mechanistically interact with the immune system and the genome, which trigger the onset of SLE and lupus flares, will certainly be one of the plausible steps to prevent the onset and to decelerate the progress of the disease.