Streptococcal infection and autoimmune diseases.

Excessive activation of immune cells by environmental factors, such as infection or individual genetic risk, causes various autoimmune diseases. Streptococcus species are gram-positive bacteria that colonize the nasopharynx, respiratory tract, gastrointestinal tract, genitourinary tract, and skin. Group A Streptococcus (GAS) species cause various symptoms, ranging from mild infections, such as tonsillitis and pharyngitis, to serious infections, such as necrotizing fasciitis and streptococcal toxic shock syndrome. The contribution of GAS infections to several autoimmune diseases, including acute rheumatic fever, vasculitis, and neuropsychiatric disorders, has been studied. In this review, we focus on the association between streptococcal infections and autoimmune diseases, and discuss current research on the mechanisms underlying the initiation and progression of autoimmune diseases.

The serological immunogenicity of the third and fourth doses of COVID-19 vaccine in patients with inflammatory rheumatic diseases on different biologic or targeted DMARDs: a Swedish nationwide study (COVID-19-REUMA).

Studies investigating the immunogenicity of additional COVID-19 vaccine doses in immunosuppressed patients with inflammatory rheumatic diseases (IRD) are still limited. The objective was to explore the antibody response including response to omicron virus subvariants (sBA.1 and sBS.2) after third and fourth COVID-19 vaccine doses in Swedish IRD patients treated with immunomodulating drugs compared to controls. Antibody levels to spike wild-type antigens (full-length protein and S1) and the omicron variants sBA.1 and sBA.2 (full-length proteins) were measured. A positive response was defined as having antibody levels over cut-off or ≥fourfold increase in post-vaccination levels for both antigens. Patients with arthritis, vasculitis, and other autoimmune diseases (n = 414), and controls (n = 61) receiving biologic/targeted synthetic disease-modifying anti-rheumatic drugs (DMARDs) with or without conventional synthetic DMARDs participated. Of these, blood samples were available for 370 patients and 52 controls after three doses, and 65 patients and 15 controls after four doses. Treatment groups after three vaccine doses were rituximab (n = 133), abatacept (n = 22), IL6r inhibitors (n = 71), JAnus Kinase inhibitors (JAK-inhibitors) (n = 56), tumor necrosis factor inhibitor (TNF-inhibitors) (n = 61), IL12/23/17 inhibitors (n = 27), and controls (n = 52). The percentage of responders after three and four vaccine doses was lower in rituximab-treated patients (59% and 57%) compared to controls (100%) (P < 0.001). After three doses, the percentage of responders in all other groups was 100%, including response to omicron sBA.1 and sBA.2. In rituximab-treated patients, higher baseline immunoglobulin G (IgG) and longer time-period between rituximab and vaccination predicted better response. In this Swedish nationwide study including IRD patients three and four COVID-19 vaccine doses were immunogenic in patients treated with IL6r inhibitors, TNF-inhibitors, JAK-inhibitors, and IL12/23/17-inhibitors but not in rituximab. As >50% of rituximab patients responded to vaccines including omicron subvariants, these patients should be prioritized for additional vaccine doses. IMPORTANCE: Results from this study provide further evidence that additional doses of COVID-19 vaccines are immunogenic and result in satisfactory antibody response in a majority of patients with inflammatory rheumatic diseases (IRD) receiving potent immunomodulating treatments such as biological or targeted disease-modifying anti-rheumatic drugs (DMARDs) given as monotherapy or combined with traditional DMARDs. We observed that rituximab treatment, both as monotherapy and combined with csDMARDs, impaired antibody response, and only roughly 50% of patients developed a satisfactory antibody response including response to omicron subvariants after the third vaccine. In addition, higher IgG levels at the last rituximab course before the third vaccine dose and a longer time after the last rituximab treatment increased the chance of a satisfactory antibody response. These results indicate that rituximab-treated patients should be prioritized for additional vaccine doses. CLINICAL TRIALS: EudraCT (European Union Drug Regulating Authorities Clinical Trials Database) with number 2021-000880-63.

Group A Streptococcus Infections.

Group A Streptococcus causes a variety of clinical manifestations, including pharyngitis and skin and soft tissue infections as well as more invasive disease. There are also multiple nonsuppurative complications of group A Streptococcus infection, including acute rheumatic fever and poststreptococcal glomerulonephritis. Pediatricians should be able to diagnose and treat the various presentations of the infection.

Outcome following acute and recurrent rheumatic fever.

BACKGROUND: Rheumatic carditis is the leading cause of permanent disability caused by damage of the cardiac valve. This study aimed to determine the outcome and predictors of valve surgery in patients with acute rheumatic fever (ARF) and recurrent rheumatic fever (RRF). METHODS: This was a retrospective study of patients diagnosed with ARF and RRF between 2006 and 2021. The predictors of valve surgery were analysed using multivariable Cox proportional regression. RESULTS: The median age of patients with ARF and RRF (n=92) was 11 years (range 5-18). Seventeen patients (18%) were diagnosed with RRF. The most common presenting symptoms included clinical carditis (87%), heart failure (HF) (63%), fever (49%) and polyarthralgia (24%). Patients with moderate-to-severe rheumatic carditis (88%) were given prednisolone. After treatment, the severity of valvular regurgitation was reduced in 52 patients (59%). Twenty-three patients (25%) underwent valve surgery. The incidence of HF, RRF, severe mitral regurgitation on presentation, left ventricular enlargement and pulmonary hypertension was greater in the surgical group than in the non-surgical group. Recurrent rheumatic fever (hazard ratio 7.9, 95% CI 1.9-33.1), tricuspid regurgitation (TR) gradient ≥ 42 mmHg (HR 6.3, 95%CI 1.1-38.7) and left ventricular end-diastolic dimension (LVEDD) ≥6 cm (HR 8.7, 95% CI 2.1-35.9) were predictors of valve surgery (multivariable Cox proportional regression analysis). CONCLUSION: Clinical carditis was the most common presenting symptom in patients with ARF and RRF. The majority of patients responded positively to prednisolone. These findings highlight the predictors of valve surgery following ARF, including RRF, TR gradient ≥ 42 mmHg and LVEDD ≥ 6 cm.Abbreviations: ARF: acute rheumatic fever; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; GAS: group A beta-haemolytic Streptococcus; HF: heart failure; HR: hazard ratio; LVEDD: left ventricular end-diastolic dimension; MR: mitral regurgitation; RHD: rheumatic heart disease; RRF: recurrent rheumatic fever; TR: tricuspid regurgitation.

Evaluating the risk of ischemic stroke at a young age in patients with autoimmune inflammatory rheumatic diseases: a population-based cohort study in Taiwan.

Background: Recent studies have demonstrated an increased incidence of ischemic stroke among patients with certain autoimmune inflammatory rheumatic diseases (AIIRDs). However, the associations between young stroke and AIIRDs have not been fully investigated. This study aimed to evaluate the risk of ischemic stroke among young patients with AIIRDs. Methods: The National Health Insurance Research Database in Taiwan was utilized to establish cohorts of patients with AIIRDs diagnosed between 2004 and 2015, who were compared with 1,000,000 control participants. Cox proportional hazards regression models were used to calculate the hazard ratio of ischemic stroke and young ischemic stroke for individual AIIRDs after adjustment for relative risk factors. Results: During the study period, a total of 64,120 patients with AIIRDss and 1,000,000 control patients were identified. The overall mean follow-up time was 5.33 years. There were 223 (0.8%) and 1,923 (0.3%) young ischemic stroke-related hospitalizations among patients with AIIRDs and controls, respectively. The incidence rate of young ischemic stroke was 0.08 in patients with rheumatoid arthritis, 0.08 in patients with Sjögren's syndrome, 0.26 in patients with systemic lupus erythematosus, 0.17 in patients with idiopathic inflammatory myositis, 0.24 in patients with systemic sclerosis, 0.05 in patients with Behçet's disease, and 0.44 in patients with systemic vasculitis, versus 0.05 per 100 person-years in the general population. The adjusted hazard ratios for young ischemic stroke were 1.07 (95% CI 0.70-1.43) for rheumatoid arthritis, 1.39 (95% CI 0.94-2.06) for Sjögren's syndrome, 5.79 (95% CI 4.68-7.17) for systemic lupus erythematosus, 2.07 for idiopathic inflammatory myositis (95% CI 0.98-4.38), 2.79 for systemic sclerosis (95% CI 1.38-5.63), 0.82 for Behçet's disease (95% CI 0.26-2.55), and 4.15 (95% CI 1.96-8.82) for systemic vasculitis. Conclusions: Patients younger than 50 years with systemic lupus erythematosus, systemic sclerosis, or systemic vasculitis have a significantly elevated risk of developing ischemic stroke. Further research is needed to elucidate the pathogenesis of accelerated atherosclerosis in these AIIRDs.

Preventive Interventions to Reduce the Burden of Rheumatic Heart Disease in Populations at Risk: A Systematic Review.

BACKGROUND: Rheumatic heart disease (RHD) is a devastating yet preventable condition that disproportionately affects low-middle-income countries and indigenous populations in some high-income countries. Various preventive interventions have been implemented across the globe, but evidence for the effectiveness of these measures in reducing the incidence or prevalence of acute rheumatic fever and RHD is scattered. This systematic review aims to assess the effectiveness of preventive interventions and identify the strategies used to reduce the burden of RHD. METHODS AND RESULTS: A comprehensive search was conducted to identify relevant studies on RHD prevention interventions including interventions for primordial, primary, and secondary prevention. Effectiveness measures for the interventions were gathered when available. The findings indicate that school-based primary prevention services targeting the early detection and treatment of Group A Streptococcus pharyngitis infection with penicillin have the potential to reduce the incidence of Group A Streptococcus pharyngitis and acute rheumatic fever. Community-based programs using various prevention strategies also reduced the burden of RHD. However, there is limited evidence from low-middle-income countries and a lack of rigorous evaluations reporting the true impact of the interventions. Narrative synthesis was performed, and the methodological quality appraisal was done using the Joanna Briggs Institute critical appraisal tools. CONCLUSIONS: This systematic review underscores the importance of various preventive interventions in reducing the incidence and burden of Group A Streptococcus pharyngitis, acute rheumatic fever, and RHD. Rigorous evaluations and comprehensive analyses of interventions are necessary for guiding effective strategies and informing public health policies to prevent and reduce the burden of these diseases in diverse populations. REGISTRATION: URL: https://www.crd.york.ac.uk/prospero/; Unique identifier: CRD42020170503.

Manifestations of Rheumatic Carditis, Regression of Valvular Regurgitation, and Independent Predictors of Mitral Regurgitation Improvement After Rheumatic Carditis in Thai Children.

Background: Acute rheumatic fever (ARF) with carditis can lead to the development of rheumatic heart disease in children and young adults. Objective: This study aimed to investigate the manifestations of rheumatic carditis, clinically significant regression of valvular regurgitation as assessed by echocardiography, and the independent predictors of mitral regurgitation (MR) improvement after rheumatic carditis in Thai children. Method: Children diagnosed with rheumatic carditis during 2005-2020 at Siriraj Hospital (Bangkok, Thailand) were retrospectively enrolled. Trivial, and mild regurgitation were grouped as non-clinically significant (NCS) regurgitation. Valvular regression was defined moderate-severe regurgitation improving to NCS regurgitation. Results: Eighty-one patients (mean age: 10 years, range: 8-12 years) were included. At presentation, 59 (72.8%) patients had combined mitral regurgitation (MR) and aortic regurgitation (AR), 20 (24.6%) patients had MR alone, and 2 (2.4%) patients had AR alone. Concerning severity, 28 (34.6%) and 30 (37%) patients presented with severe and moderate MR, respectively. Severe and moderate AR was found in 9 (11.1%) and 16 (19.8%) patients, respectively. At the one-year follow-up, 43.4% of moderate-severe MR, and 41.7% of moderate-severe AR improved to NCS regurgitation. Multivariate analysis revealed high erythrocyte sedimentation rate (ESR) (p = 0.01) and severe carditis (p = 0.05) at presentation to be independent predictors of MR improvement. Conclusion: Thai children with rheumatic carditis had a high incidence of valvular regurgitation; however, the valvular damage was improved in most patients. High ESR and severe carditis independently predict MR improvement.

Outcomes of rheumatic fever in Uganda: a prospective cohort study.

BACKGROUND: Rheumatic heart disease is the largest contributor to cardiac-related mortality in children worldwide. Outcomes in endemic settings after its antecedent illness, acute rheumatic fever, are not well understood. We aimed to describe 3-5 year mortality, acute rheumatic fever recurrence, changes in carditis, and correlates of mortality after acute rheumatic fever. METHODS: We conducted a prospective cohort study of Ugandan patients aged 4-23 years who were diagnosed with definite acute rheumatic fever using the modified 2015 Jones criteria from July 1, 2017, to March 31, 2020, enrolled at three rheumatic heart disease registry sites in Uganda (in Mbarara, Mulago, or Lira), and followed up for at least 1 year after diagnosis. Patients with congenital heart disease were excluded. Patients underwent annual review, most recently in August, 2022. We calculated rates of mortality and acute rheumatic fever recurrence, tabulated changes in carditis, performed Kaplan-Meier survival analyses, and used Cox regression models to identify correlates of mortality. FINDINGS: Data were collected between Sept 1 and Sept 30, 2022. Of 182 patients diagnosed with definite acute rheumatic fever, 156 patients were included in the analysis. Of these 156 patients (77 [49%] male and 79 (51%) female; data on ethnicity not collected), 25 (16%) died, 21 (13%) had a cardiac-related death, and 17 (11%) had recurrent acute rheumatic fever over a median of 4·3 (IQR 3·0-4·8) years. 16 (24%) of the 25 deaths occurred within 1 year. Among 131 (84%) of 156 survivors, one had carditis progression by echo. Moderate-to-severe carditis (hazard ratio 12·7 [95% CI 3·9-40·9]) and prolonged PR interval (hazard ratio 4·4 [95% CI 1·7-11·2]) at acute rheumatic fever diagnosis were associated with increased cardiac-related mortality. INTERPRETATION: These are the first contemporary data from sub-Saharan Africa on medium-term acute rheumatic fever outcomes. Mortality rates exceeded those reported elsewhere. Most decedents already had chronic carditis at initial acute rheumatic fever diagnosis, suggesting previous undiagnosed episodes that had already compounded into rheumatic heart disease. Our data highlight the large burden of undetected acute rheumatic fever in these settings and the need for improved awareness of and diagnostics for acute rheumatic fever to allow earlier detection. FUNDING: Strauss Award at Cincinnati Children's Hospital, American Heart Association, and Wellcome Trust.

The gut microbiome in systemic lupus erythematosus: lessons from rheumatic fever.

For more than a century, certain bacterial infections that can breach the skin and mucosal barriers have been implicated as common triggers of autoimmune syndromes, especially post-infection autoimmune diseases that include rheumatic fever and post-streptococcal glomerulonephritis. However, only in the past few years has the importance of imbalances within our own commensal microbiota communities, and within the gut, in the absence of infection, in promoting autoimmune pathogenesis become fully appreciated. A diversity of species and mechanisms have been implicated, including disruption of the gut barrier. Emerging data suggest that expansions (or blooms) of pathobiont species are involved in autoimmune pathogenesis and stimulate clonal expansion of T cells and B cells that recognize microbial antigens. This Review discusses the relationship between the gut microbiome and the immune system, and the potential consequence of disrupting the community balance in terms of autoimmune development, focusing on systemic lupus erythematosus. Notably, inter-relationships between expansions of certain members within gut microbiota communities and concurrent autoimmune responses bear features reminiscent of classical post-infection autoimmune disease. From such insights, new therapeutic opportunities are being considered to restore the balance within microbiota communities or re-establishing the gut-barrier integrity to reinforce immune homeostasis in the host.

A foodborne outbreak of Group A streptococcus: an under-recognised method of spread.

Foodborne transmission of Group A Streptococcus (GAS) is a rare cause of pharyngitis outbreaks. This report details a GAS outbreak in New Zealand that was associated with a foodborne route of transmission. This outbreak was relevant in the New Zealand context given the high incidence of rheumatic fever (RF).

State transitions across the Strep A disease spectrum: scoping review and evidence gaps.

The spectrum of diseases caused by Streptococcus pyogenes (Strep A) ranges from superficial to serious life-threatening invasive infections. We conducted a scoping review of published articles between 1980 and 2021 to synthesize evidence of state transitions across the Strep A disease spectrum. We identified 175 articles reporting 262 distinct observations of Strep A disease state transitions. Among the included articles, the transition from an invasive or toxin-mediated disease state to another disease state (i.e., to recurrent ARF, RHD or death) was described 115 times (43.9% of all included transition pairs) while the transition to and from locally invasive category was the lowest (n = 7; 0.02%). Transitions from well to any other state was most frequently reported (49%) whereas a relatively higher number of studies (n = 71) reported transition from invasive disease to death. Transitions from any disease state to locally invasive, Strep A pharyngitis to invasive disease, and chronic kidney disease to death were lacking. Transitions related to severe invasive diseases were more frequently reported than superficial ones. Most evidence originated from high-income countries and there is a critical need for new studies in low- and middle-income countries to infer the state transitions across the Strep A disease spectrum in these high-burden settings.

Revising the value of Antistreptolysin O titre in childhood and its interpretation in the diagnostic approach of rheumatic diseases.

The burden of group A streptococcus (GAS) infection and its rheumatic sequelae remains dramatically high, especially in low-income countries. Recently, an increased number of Acute Rheumatic Fever (ARF) cases was documented in many regions of Italy. The diagnosis of rheumatic sequelae relies on clinical signs and on the evaluation of the Antistreptolysin O titre (ASO), whose variations are globally reported. To re-examine the standard reference value of ASO titre, by measuring either its upper limit of normal (ULN) in a population of healthy children (HC) or comparing these values with streptococcal antibodies registered in a cohort of patients affected by the rheumatic sequelae of GAS infection. We performed a multicenter retrospective study. We enrolled 125 HC, aged 2-17 years, and a total of 181 patients affected by ARF, acute streptococcal pharyngitis, post-streptococcal arthritis, Henoch-Schönlein purpura and erythema nodosum, divided into four groups. The levels of ASO and anti-deoxyribonuclease B (anti-DNase B) titres were analyzed and compared among the various groups. Moreover, the 80th percentile value was calculated and established as the ULN for ASO titre in HC group. The ULN for ASO titre in overall HC group was 515 IU/mL, resulting in higher than used in the routine investigation. The ASO titre was significantly higher in patients with rheumatic sequelae compared with HC group, with a peak in the age between 5 and 15 years.    Conclusion: Our study established a new ULN normal value of streptococcal serology in a childhood and adolescent population of Italy, suggesting the need to extend this revaluation to the critical areas, in order to avoid underestimating ARF diagnosis. The correct interpretation of ASO and anti-DNase B values in the context of rheumatic diseases has been discussed. What is Known: • The global burden of disease caused by group A streptococcus is not known and remains an important cause of morbidity and mortality. Acute rheumatic fever continues to be a serious worldwide public health problem and a recent recurrence of group A streptococcus infection cases is observed. • The streptococcal sequelae requires evidence of preceding streptococcal infection, commonly elevated streptococcal antibody titre, but the upper limit for these titres varies considerably based on age group, region, and origin. What is New: • This study provides population-specific values for streptococcal antibody titres in Italy. • Interpret the results of group A streptococcal antibody tests within the clinical context.

[Rheumatic cardiopathies and its risk factors: about 50 cases]. / Les complications cardiaques du rhumatisme articulaire aigu et ses facteurs de risque : étude de 50 observations.

INTRODUCTION: Acute rheumatic fever (ARF) is a multi-systemic disease, in which cardiac involvement is the most serious major manifestation of disease. The aim of this study was to analyse cardiac involvement in children with ARF and his risk factors. MATERIALS AND METHODS: It were a retrospective study including all children under the age of 14 years who were hospitalized for ARF in the pediatric department of the CHU Hédi Chaker of Sfax, during a period of twelve years (2010-2022). RESULTS: We collected 50 cases (31 boys and 19 girls). Twenty-two patients (44%) developed cardiac lesions. The mean age at diagnosis was 9.6 years [5-14 years]. A pathological heart murmur was detected in 14 cases (n = 14/22) was classified as mild carditis in 15 cases, moderate carditis in 5 cases and severe in 2 cases. The median follow-up time was 3,3 years. Nineteen patients developed valvular sequelae Risk factors of cardiac lesions was: age more than 8 years, heart murmur, allonged PR, CRP > 100 mg/l and VS > 100 mm. CONCLUSION: CR is still a public health problem in Tunisia. It is a serious pathology that can cause serious increases in morbidity rates. Thus, we must strengthen preventive strategies.

Disseminated tuberculosis after anti-TNF alpha treatment: Do not blindly trust the IGRA test.

INTRODUCTION: Interferon gamma release assay (IGRA) is used to detect latent tuberculosis prior to biological treatments in the context of suspected inflammatory rheumatism. METHODS: We report the case of a 50-year-old woman with negative IGRA test before adalimumab introduction for presumed axial spondyloarthritis. RESULTS: The worsening of symptoms under treatment led to further investigations and the diagnostic of disseminated tuberculosis (TB) was later established with miliary and multiple bone locations such as spondylitis and sacroilitis. The patient's history revealed past exposure to tuberculosis. This observation illustrates the limitations of IGRA in such situation due to its variable performance for active TB diagnosis. CONCLUSION: Misdiagnosis is frequent in bone tuberculosis due to non-specific signs. We draw the attention to the importance of a global risk assessment prior to the introduction of biological treatment for suspected chronic inflammatory rheumatism and recall the risk factors for false-negative IGRA. An extended treatment course may be necessary after exposure to anti-TNF-alpha.

[Influence of underlying disease and immunosuppression on the immunocompetence in inflammatory rheumatic diseases]. / Einfluss von Grunderkrankung und Immunsuppression auf die Immunkompetenz bei entzündlich rheumatischen Erkrankungen.

Patients with inflammatory rheumatic diseases have a higher risk of infections in comparison to the general population. For this patient group, in addition to cardiovascular diseases, infections play an important role with respect to morbidity and mortality. Even if it is difficult to make concrete statements with respect to individual diseases, it can be assumed that there is a lower risk of infections in inflammatory joint diseases in comparison to connective tissue diseases and vasculitides. The increased risk of infections is determined by multiple factors, whereby the underlying factors are classified into three main categories: patient-related factors (age, comorbidities, lifestyle), disease-related factors (immunological dysfunction as part of the disease pathophysiology) and drug-related factors (type and dosage of the immunosuppression and/or immunomodulation). An improved understanding of the complexity of these associations enables the optimization of treatment and disease control taking the individual risk factors into account, with the aim of a significant reduction in the risk of infections.