Genetics of rheumatic fever and rheumatic heart disease

A study protocol to characterise pathophysiological and molecular markers of rheumatic heart disease and degenerative aortic stenosis using multiparametric cardiovascular imaging and multiomics techniques

INTRODUCTION

Rheumatic heart disease (RHD), degenerative aortic stenosis (AS), and congenital valve diseases are prevalent in sub-Saharan Africa. Many knowledge gaps remain in understanding disease mechanisms, stratifying phenotypes, and prognostication. Therefore, we aimed to characterise patients through clinical profiling, imaging, histology, and molecular biomarkers to improve our understanding of the pathophysiology, diagnosis, and prognosis of RHD and AS.

METHODS

In this cross-sectional, case-controlled study, we plan to recruit RHD and AS patients and compare them to matched controls. Living participants will undergo clinical assessment, echocardiography, CMR and blood sampling for circulatory biomarker analyses. Tissue samples will be obtained from patients undergoing valve replacement, while healthy tissues will be obtained from cadavers. Immunohistology, proteomics, metabolomics, and transcriptome analyses will be used to analyse circulatory- and tissue-specific biomarkers. Univariate and multivariate statistical analyses will be used for hypothesis testing and identification of important biomarkers. In summary, this study aims to delineate the pathophysiology of RHD and degenerative AS using multiparametric CMR imaging. In addition to discover novel biomarkers and explore the pathomechanisms associated with RHD and AS through high-throughput profiling of the tissue and blood proteome and metabolome and provide a proof of concept of the suitability of using cadaveric tissues as controls for cardiovascular disease studies.

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.

Research priorities for the secondary prevention and management of acute rheumatic fever and rheumatic heart disease: a National Heart, Lung, and Blood Institute workshop report

Secondary prevention of acute rheumatic fever (ARF) and rheumatic heart disease (RHD) involves continuous antimicrobial prophylaxis among affected individuals and is recognised as a cornerstone of public health programmes that address these conditions. However, several important scientific issues around the secondary prevention paradigm remain unresolved. This report details research priorities for secondary prevention that were developed as part of a workshop convened by the US National Heart, Lung, and Blood Institute in November 2021. These span basic, translational, clinical and population science research disciplines and are built on four pillars. First, we need a better understanding of RHD epidemiology to guide programmes, policies, and clinical and public health practice. Second, we need better strategies to find and diagnose people affected by ARF and RHD. Third, we urgently need better tools to manage acute RF and slow the progression of RHD. Fourth, new and existing technologies for these conditions need to be better integrated into healthcare systems. We intend for this document to be a reference point for research organisations and research sponsors interested in contributing to the growing scientific community focused on RHD prevention and control.

Health-related quality of life and healthcare consultations among adult patients before and after diagnosis with rheumatic heart disease in Namibia

BACKGROUND

Rheumatic Heart Disease (RHD) causes high morbidity and mortality rates among children and young adults, impacting negatively on their health-related quality of life (HRQoL). This study aimed to evaluate the HRQoL and healthcare consultations of adult patients with RHD in Namibia.

METHODS

From June 2019 to March 2020, a questionnaire was administered to 83 RHD patients during routine follow-ups. The EQ-5D-5L instrument was used to assess the health-related quality of life before diagnosis and at the time of the survey. The Ethiopian value set for EQ-5D-5L was used to calculate Quality-Adjusted Life Years (QALY).

RESULTS

Most respondents were women (77%), young adults below the age of 30 years (42%), and individuals who grew up in rural areas (87%). The mean QALY statistically significantly improved from 0.773 pre-diagnosis to 0.942 in the last 12 months (p < 0.001). Sixty-six patients who had surgery reported a better QALY. Healthcare visits statistically significantly increased from on average 1.6 pre-diagnosis to 2.7 days in the last 12 months (p < 0.001). The mean distance to the nearest facility was 55 km, mean cost of transport was N$65, and mean time spent at the clinic was 3.6 h. The median time from diagnosis to the survey was 7 years (quartiles 4 and 14 years).

CONCLUSION

Treatment and surgery can improve HRQoL substantially among RHD patients. Being diagnosed with RHD affects patients living in socioeconomically disadvantaged rural areas through cost and time for healthcare visits. It would be valuable with further research to understand differences between disease severities.

The Immunomodulatory Role of Microbiota in Rheumatic Heart Disease: What Do We Know and What Can We Learn from Other Rheumatic Diseases?

Rheumatic heart disease (RHD) represents a serious cardiac sequela of acute rheumatic fever, occurring in 30-45% of patients. RHD is multifactorial, with a strong familial predisposition and known environmental risk factors that drive loss of immunological tolerance. The gut and oral microbiome have recently been implicated in the pathogenesis of RHD. Disruption of the delicate balance of the microbiome, or dysbiosis, is thought to lead to autoimmune responses through several different mechanisms including molecular mimicry, epitope spreading, and bystander activation. However, data on the microbiomes of RHD patients are scarce. Therefore, in this comprehensive review, we explore the various dimensions of the intricate relationship between the microbiome and the immune system in RHD and other rheumatic diseases to explore the potential effect of microbiota on RHD and opportunities for diagnosis and treatment.

The Role of «Novel» Biomarkers of Systemic Inflammation in the Development of Early Hospital Events after Aortic Valve Replacement in Patients with Aortic Stenosis

INTRODUCTION

The pathogenesis of aortic stenosis includes the processes of chronic inflammation, calcification, lipid metabolism disorders, and congenital structural changes. The goal of our study was to determine the predictive value of novel biomarkers of systemic inflammation and some hematological indices based on the numbers of leukocytes and their subtypes in the development of early hospital medical conditions after mechanical aortic valve replacement in patients with aortic stenosis.

MATERIALS AND METHODS

This was a cohort study involving 363 patients who underwent surgical intervention for aortic valve pathology between 2014 and 2020. The following markers of systemic inflammation and hematological indices were studied: SIRI (Systemic Inflammation Response Index), SII (Systemic Inflammation Index), AISI (Aggregate Index of Systemic Inflammation), NLR (Neutrophil/Lymphocyte Ratio), PLR (Platelet/Lymphocyte Ratio), and MLR (Monocyte/Lymphocyte Ratio). Associations of the levels of these biomarkers and indices with the development of in-hospital death, acute kidney injury, postoperative atrial fibrillation, stroke/acute cerebrovascular accident, and bleeding were calculated.

RESULTS

According to an ROC analysis, an SIRI > 1.5 (p < 0.001), an SII > 718 (p = 0.002), an AISI > 593 (p < 0.001), an NLR > 2.48 (p < 0.001), a PLR > 132 (p = 0.004), and an MLR > 0.332 (p < 0.001) were statistically significantly associated with in-hospital death. Additionally, an SIRI > 1.5 (p < 0.001), an NLR > 2.8 (p < 0.001), and an MLR > 0.392 (p < 0.001) were associated with bleeding in the postoperative period. In a univariate logistic regression, SIRI, SII, AISI, and NLR were statistically significant independent factors associated with in-hospital death. In a multivariate logistic regression model, SIRI was the most powerful marker of systemic inflammation.

CONCLUSION

SIRI, SII, AISI, and NLR as novel biomarkers of systemic inflammation were associated with in-hospital mortality. Of all markers and indices of systemic inflammation in our study, SIRI was the strongest predictor of a poor outcome in the multivariate regression model.

The microbiome and rheumatic heart disease: current knowledge and future perspectives

Rheumatic heart disease (RHD) is a cardiovascular disease caused by an autoimmune response to group A Streptococcus (GAS) infection resulting in the damage of heart valves. RHD is the most commonly acquired heart disease among children and young adults with a global burden of over 40 million cases accounting for 306,000 deaths annually. Inflammation in the heart valves caused due to molecular mimicry between the GAS antigens and host cardiac proteins is facilitated by cytokines, cross-reactive antibodies and CD4⁺ T cells. The complex interaction between genetic and environmental factors linked with erratic events leads to the loss of immunological tolerance and autoimmunity in RHD. Despite extensive research on the etiopathogenesis of RHD, the precise mechanism underpinning the initiation of acute rheumatic fever (ARF) to the progression of RHD still remains elusive. Mounting evidences support the contribution of the human microbiome in the development of several immune-mediated diseases including rheumatoid arthritis, juvenile idiopathic arthritis, Kawasaki disease, inflammatory bowel disease and type 1 diabetes. The microbiome and their metabolites could play a crucial role in the integrity of the epithelial barrier, development of the immune system, inflammation and differentiation of T cell subsets. Consequently, microbiome dysbiosis might result in autoimmunity by molecular mimicry, epitope spreading and bystander activation. This review discusses various aspects of the interaction between the microbiome and the immune system in order to reveal causative links relating dysbiosis and autoimmune diseases with special emphasis on RHD.

The Impact of ACE Gene Variants on Acute-Phase Reactants in Children with Rheumatic Heart Disease

Rheumatic heart disease (RHD) is the most important sequela of upper respiratory group A Streptococcus (GAS) infection. The role of the common angiotensin-converting enzyme (ACE) insertion/deletion (I/D) variant in the disease and its subtypes remains uncertain. The acute-phase reactants (APRs) C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) form part of the Jones criteria for diagnosing RHD, and genetic factors are known to influence baseline CRP and ESR levels. Therefore, here, we investigated the relationship between the ACE I/D polymorphism and APR levels in RHD. A total of 268 individuals were recruited, including 123 RHD patients and 198 healthy controls. There was a trend toward a higher D allele frequency in RHD patients. The ACE I/D polymorphism genotype frequency and DD+ID allelic carriage were significantly associated with a high APR level (p = 0.04 and p = 0.02, respectively). These results highlight the importance of ACE I/D polymorphisms in RHD for disease stratification, but not for disease predisposition. Further studies in larger cohorts and different populations are now required to confirm this association and to explore the mechanism of this effect.

Rheumatic valvular heart disease treated with traditional Chinese medicine: A case report

BACKGROUND

Rheumatic heart disease (RHD) is an autoimmune disease that leads to irreversible valve damage and heart failure. Surgery is an effective treatment; however, it is invasive and carries risks, restricting its broad application. Therefore, it is essential to find alternative nonsurgical treatments for RHD.

CASE SUMMARY

A 57-year-old woman was assessed with cardiac color Doppler ultrasound, left heart function tests, and tissue Doppler imaging evaluation at Zhongshan Hospital of Fudan University. The results showed mild mitral valve stenosis with mild to moderate mitral and aortic regurgitation, confirming a diagnosis of rheumatic valve disease. After her symptoms became severe, with frequent ventricular tachycardia and supraventricular tachycardia > 200 beats per minute, her physicians recommended surgery. During a 10-day preoperative waiting period, the patient asked to be treated with traditional Chinese medicine. After 1 week of this treatment, her symptoms improved significantly, including resolution of the ventricular tachycardia, and the surgery was postponed pending further follow-up. At 3 -month follow-up, color Doppler ultrasound showed mild mitral valve stenosis with mild mitral and aortic regurgitation. Therefore, it was determined that no surgical treatment was required.

CONCLUSION

Traditional Chinese medicine treatment effectively relieves symptoms of RHD, particularly mitral valve stenosis and mitral and aortic regurgitation.

Ventricular strain patterns in multivalvular heart disease: a cross-sectional study

Multivalvular heart disease (MVD) is an aggregate of regurgitant and/or stenotic lesions of at least two cardiac valves. Ventricular tissue deformation imaging is a powerful predictor of subclinical myocardial dysfunction in patients with MVD.The aim of this study was to examine the left and right ventricular strain patterns in MVD as well as observe any association between right-sided valvular involvement (tricuspid or pulmonary valve lesion) with that of aortic and/or mitral valve lesion. Patients with at least moderate forms of MVD were included in the present study. 72 patients with mean age of 56.69 ± 14.59 years and various presentations of MVD were finally enrolled in this study. The commonest cause for MVD was rheumatic heart disease in these patients. Conventional 2-dimensional parameters as well as tissue deformation imaging parameters were assessed in offline mode for these patients. The Mean ± SD values for various quantitative 2D echocardiographic conventional and tissue deformation imaging were assessed. It was observed that LV strain parameters including the global longitudinal strain (GLS) were preserved whereas the RV strain parameters were mildly reduced (RV GLS total is - 19.49 ± 6.08%). Also, when conventional echocardiographic parameters were assessed to see any association between aortic and/or mitral valve disease with that of right-sided valvular lesions (tricuspid or pulmonary); 2D conventional echocardiographic parameters like left atrial dimension (p = 0.034), TAPSE (tricuspid annular plane systolic excursion) (p < 0.001), RVSP (right ventricular systolic pressure) (p < 0.001) and IVC (inferior vena cava) dimensions (p < 0.001) showed a statistically significant result; whereas, when strain parameters for LV and RV were assessed, they did not show any statistical difference for the same. In this series of patients with significant MVD, our findings suggest that ventricular strain parameters may be reliable markers of myocardial dysfunction, but may alter depending on the underlying combination of MVD, and right ventricular strain should also be an important parameter while assessing different combinations of MVD.

Targeting Environmental Risks to Prevent Rheumatic Disease

Targeting environmental factors can be an important way to reduce the incidence of rheumatic diseases (RDs). Such approaches may be at population levels; furthermore, an emerging ability to identify an individual who is at very high risk for the development of a future RD can allow for personalized approaches to environmental modification for prevention. In this article, we will discuss challenges and opportunities to targeting environmental factors for the prevention of RDs.

Value of the systemic immune-inflammation index in predicting poor postoperative outcomes and the short-term prognosis of heart valve diseases: a retrospective cohort study

OBJECTIVE

Systemic immune-inflammation index (SII) is a novel biomarker that can predict poor outcomes in tumours, nervous system diseases and chronic heart failure. Here, we investigated the predictive value of SII on the poor postoperative outcomes and short-term prognosis of heart valve diseases (HVDs).

DESIGN, SETTING AND PARTICIPANTS

This retrospective cohort study enrolled all consecutive patients with HVDs (aortic stenosis, aortic regurgitation, mitral stenosis and mitral regurgitation) who underwent surgery (valve replacement or valve repair) at the Affiliated Hospital of North Sichuan Medical College between 2017 and 2020.

MAIN OUTCOMES AND MEASURES

Major complications in the perioperative period, all-cause mortality within 30 days and readmission within 30 days.

RESULTS

A total of 431 patients with HVDs were enrolled in this study, including 202 males and 229 females, aged 58.9±27.3 years. SII levels of patients in the poor outcomes group were significantly higher than those of patients in the favourable outcomes group (658.40±436.29 vs 335.72±174.76, respectively; p<0.001). Multivariate logistic regression analysis showed that age (OR 1.064, 95% CI 1.026 to 1.104, p=0.025), SII (OR 1.034, 95% CI 1.012 to 1.631, p=0.008) and aortic cross-clamping time (OR 1.013, 95% CI 1.004 to 1.023, p=0.006) were independent risk factors for poor outcomes and short-term prognosis in patients with HVD. The area under the curve of poor outcomes predicted by SII in patients with HVD was 0.806 (95% CI 0.763 to 0.848) and the optimised cut-off value 423.8×10⁹ /L, with a sensitivity of 70.3% and specificity of 81.1%. The incidence of poor outcomes (p<0.001), 30-day mortality (p<0.001) and 30-day readmission rate (p=0.026) in the high SII group was significantly higher than that in the low SII group.

CONCLUSIONS

SII is closely related to poor postoperative outcomes and short-term prognosis of HVD and can serve as an independent predictive factor.

Rheumatic heart disease prevalence in Namibia: a retrospective review of surveillance registers

Background

Rheumatic heart disease (RHD) is the most commonly acquired heart disease in children and young people in low and middle-income settings. Fragile health systems and scarcity of data persist to limit the understanding of the relative burden of this disease. The aims of this study were to estimate the prevalence of RHD and to assess the RHD-related health care systems in Namibia.

Methods

Data was retrieved from outpatient and inpatient registers for all patients diagnosed and treated for RHD between January 2010 to December 2020. We used descriptive statistics to estimate the prevalence of RHD. Key observations and engagement with local cardiac clinicians and patients helped to identify key areas of improvement in the systems.

Results

The outpatient register covered 0.032% of the adult Namibian population and combined with the cumulative incidence from the inpatient register we predict the prevalence of clinically diagnosed RHD to be between 0.05% and 0.10% in Namibia. Young people (< 18 years old) are most affected (72%), and most cases are from the north-eastern regions. Mitral heart valve impairment (58%) was the most common among patients. We identified weaknesses in care systems i.e., lack of patient unique identifiers, missing data, and clinic-based prevention activities.

Conclusion

The prevalence of RHD is expected to be lower than previously reported. It will be valuable to investigate latent RHD and patient follow-ups for better estimates of the true burden of disease. Surveillance systems needs improvements to enhance data quality. Plans for expansions of the clinic-based interventions must adopt the “Awareness Surveillance Advocacy Prevention” framework supported by relevant resolutions by the WHO.

Network analysis of genes associated with esophageal squamous cell carcinoma progression

This study aims to identify possible genes associated with esophageal squamous cell carcinoma (ESCC) by bioinformatics tool and further explore the function of immunoglobulin heavy chain variable family 4 gene (IGHV4)-28 in the ESCC progression.The ESCC-related genes in Cancer Genome Atlas (TCGA) database were analyzed by bioinformatics tools, which finally identified IGHV4-28. The expression levels of IGHV4-28 in TE-4 and EC9706 cells were detected by quantitative reverse transcription-PCR (qRT-PCR). Then oe-IGHV4-28 or sh-IGHV4-28 was transfected into TE-4 and EC9706 cells to verify the effect on cell proliferation, migration, invasion, and apoptosis rate. In vivo, a nude mouse model of ESCC was developed, whereby the tumor volume and weight were calculated to evaluate the impact of IGHV4-8 on tumor growth.Bioinformatics analysis using TCGA database showed that IGHV4-28, IGLV6-57, and KPRP were all associated with ESCC progression. Kaplan-Meier (KM) analysis showed overexpression of IGHV4-28 is substantially associated with the survival rate of patients with ESCC. IGHV4-28 was highly expressed in TE-4 and EC9706 cell lines and overexpression of IGHV4-28 enhanced cell proliferation, invasion, and migration, as well as decreased apoptosis rate. Moreover, nude mice transplanted with IGHV4-28-silencing TE-4 cells showed restrained tumor weight and volume.In summary, IGHV4-28 was increasingly expressed in ESCC and may serve as a therapeutic target in the treatment of ESCC.

Rheumatic fever in a developed country - is it still relevant? A retrospective, 25 years follow-up

BACKGROUND

Our aims were to clinically and epidemiologically characterize rheumatic fever (RF) in the current era in Israel. Although there has been a steady decline in the incidence of RF in the western world, evidence of disease resurgence in developed countries continues to be published. The paucity of recent epidemiological data prompted our study.

METHODS

Medical files were retrospectively reviewed for all children with RF in our tertiary pediatric university-affiliated hospital from 1993 to 2017. Main outcome measures were patients and disease related characteristics, incidence trends, risk factors, disease course, relapse rates and secondary prophylaxis.

RESULTS

The cohort included 307 children. Sixty-four percent presented with arthritis, interestingly including hips and small joints of hands and feet at presentation, 52% presented with carditis. Severe carditis developed in 31 patients (19.5%), of whom 21 (13.2% of all carditis patients) acquired heart failure, 5 required intensive care monitoring, with one recent death. The percentage of patients with acute carditis of the overall RF patients remained relatively stable. Thirty-two patients (10% of patients with RF) relapsed, including 11 with a cardiac relapse (3.6% of all cardiac patients). The recurrence rate of RF continued to rise up to 9 years from the initial episode. One of 147 patients (< 0.7%) with a non-cardiac initial presentation had carditis at relapse.

CONCLUSION

RF and rheumatic heart disease remain an important cause of morbidity and mortality including developed countries, with relapse rate continuing after 9 years of prophylaxis. Presentation of small joints as well as hips, although uncommon, should not exclude the diagnosis.

Recent Advances in the Rheumatic Fever and Rheumatic Heart Disease Continuum

Nearly a century after rheumatic fever (RF) and rheumatic heart disease (RHD) was eradicated from the developed world, the disease remains endemic in many low- and middle-income countries (LMICs), with grim health and socioeconomic impacts. The neglect of RHD which persisted for a semi-centennial was further driven by competing infectious diseases, particularly the human immunodeficiency virus (HIV) pandemic. However, over the last two-decades, slowly at first but with building momentum, there has been a resurgence of interest in RF/RHD. In this narrative review, we present the advances that have been made in the RF/RHD continuum over the past two decades since the re-awakening of interest, with a more concise focus on the last decade’s achievements. Such primary advances include understanding the genetic predisposition to RHD, group A Streptococcus (GAS) vaccine development, and improved diagnostic strategies for GAS pharyngitis. Echocardiographic screening for RHD has been a major advance which has unearthed the prevailing high burden of RHD and the recent demonstration of benefit of secondary antibiotic prophylaxis on halting progression of latent RHD is a major step forward. Multiple befitting advances in tertiary management of RHD have also been realized. Finally, we summarize the research gaps and provide illumination on profitable future directions towards global eradication of RHD.

Hsa_circ_0000437 upregulates and promotes disease progression in rheumatic valvular heart disease

Background

Currently, the diagnosis and outcome of rheumatic valvular heart disease (RVHD) are less than ideal, and there are no accurate biomarkers. Circular RNA (circRNA) might participate in the occurrence and development of RVHD.

Materials and methods

We use circRNA microarray to filter out the target has_circ_0000437. qRT‐PCR was used to measure the expression levels of hsa_circ_0000437 in RVHD plasma samples. We assessed the diagnostic value of hsa_circ_0000437 in RVHD. Cell function in vitro experiment was to explore the effect of has_circ_0000437 on RVHD.

Results

Has_circ_0000437 is highly expressed in RVHD (p < 0.001). has_circ_0000437 has the diagnostic value in RVHD. In RVHD, hsa_circ_0000437 can promote cell proliferation and migration but inhibits its apoptosis. This may be due to the combination of has_circ_0000437 and target miRNA in the cytoplasm that affects the progress of RVHD.

Conclusions

Has_circ_0000437 can promote the process of RVHD and may be a potential for the diagnosis and treatment of RVHD.

Predictors of rheumatic fever in sore throat patients: a systematic review and meta-analysis

Background

Concerns about rheumatic fever (RF) drive antibiotic prescriptions for sore throat (ST) in endemic areas. Better guidance is needed on which patients are likely to develop RF in order to avoid misuse and overuse of antibiotics. Our aim was to identify predictive factors for RF in ST patients.

Methods

Multiple databases were searched to identify cohort, case–control, cross-sectional or randomised controlled trials that measured RF incidence in ST patients. An inverse variance random effects model was used to pool the data and calculate odds ratios (ORs).

Results

Seven studies with a total of 6890 participants were included: three RCTs and four observational studies. Factors significantly associated with RF development following ST were positive group A streptococcal (GAS) swab (OR 1.74 [95% confidence interval {CI} 1.13 to 2.69]), previous RF history (OR 13.22 [95% CI 4.86 to 35.93]) and a cardiac murmur (OR 3.55 [95% CI 1.81 to 6.94]). Many potential risk factors were not reported in any of the included studies, highlighting important evidence gaps.

Conclusions

ST patients in endemic areas with a positive GAS swab, previous RF history and a cardiac murmur are at increased risk of developing RF. This review identifies vital gaps in our knowledge of factors predicting RF development in ST patients. Further research is needed to develop better clinical prediction tools and rationalise antibiotic use for ST.

Association of Novel Locus With Rheumatic Heart Disease in Black African Individuals: Findings From the RHDGen Study

Importance

Rheumatic heart disease (RHD), a sequela of rheumatic fever characterized by permanent heart valve damage, is the leading cause of cardiac surgery in Africa. However, its pathophysiologic characteristics and genetics are poorly understood. Understanding genetic susceptibility may aid in prevention, control, and interventions to eliminate RHD.

Objective

To identify common genetic loci associated with RHD susceptibility in Black African individuals.

Design, Setting, and Participants

This multicenter case-control genome-wide association study (GWAS), the Genetics of Rheumatic Heart Disease, examined more than 7 million genotyped and imputed single-nucleotide variations. The 4809 GWAS participants and 116 independent trio families were enrolled from 8 African countries between December 31, 2012, and March 31, 2018. All GWAS participants and trio probands were screened by use of echocardiography. Data analyses took place from May 15, 2017, until March 14, 2021.

Main Outcomes and Measures

Genetic associations with RHD.

Results

This study included 4809 African participants (2548 RHD cases and 2261 controls; 3301 women [69%]; mean [SD] age, 36.5 [16.3] years). The GWAS identified a single RHD risk locus, 11q24.1 (rs1219406 [odds ratio, 1.65; 95% CI, 1.48-1.82; P = 4.36 × 10-8]), which reached genome-wide significance in Black African individuals. Our meta-analysis of Black (n = 3179) and admixed (n = 1055) African individuals revealed several suggestive loci. The study also replicated a previously reported association in Pacific Islander individuals (rs11846409) at the immunoglobulin heavy chain locus, in the meta-analysis of Black and admixed African individuals (odds ratio, 1.16; 95% CI, 1.06-1.27; P = 1.19 × 10-3). The HLA (rs9272622) associations reported in Aboriginal Australian individuals could not be replicated. In support of the known polygenic architecture for RHD, overtransmission of a polygenic risk score from unaffected parents to affected probands was observed (polygenic transmission disequilibrium testing mean [SE], 0.27 [0.16] SDs; P = .04996), and the chip-based heritability was estimated to be high at 0.49 (SE = 0.12; P = 3.28 × 10-5) in Black African individuals.

Conclusions and Relevance

This study revealed a novel candidate susceptibility locus exclusive to Black African individuals and an important heritable component to RHD susceptibility in African individuals.

Casomorphins and Gliadorphins Have Diverse Systemic Effects Spanning Gut, Brain and Internal Organs

Food-derived opioid peptides include digestive products derived from cereal and dairy diets. If these opioid peptides breach the intestinal barrier, typically linked to permeability and constrained biosynthesis of dipeptidyl peptidase-4 (DPP4), they can attach to opioid receptors. The widespread presence of opioid receptors spanning gut, brain, and internal organs is fundamental to the diverse and systemic effects of food-derived opioids, with effects being evidential across many health conditions. However, manifestation delays following low-intensity long-term exposure create major challenges for clinical trials. Accordingly, it has been easiest to demonstrate causal relationships in digestion-based research where some impacts occur rapidly. Within this environment, the role of the microbiome is evidential but challenging to further elucidate, with microbiome effects ranging across gut-condition indicators and modulators, and potentially as systemic causal factors. Elucidation requires a systemic framework that acknowledges that public-health effects of food-derived opioids are complex with varying genetic susceptibility and confounding factors, together with system-wide interactions and feedbacks. The specific role of the microbiome within this puzzle remains a medical frontier. The easiest albeit challenging nutritional strategy to modify risk is reduced intake of foods containing embedded opioids. In future, constituent modification within specific foods to reduce embedded opioids may become feasible.

The "Cairo Accord"- Towards the Eradication of RHD: An Update

Rheumatic heart disease (RHD) is the most common cause of acquired heart disease in children and young adults. It continues to be prevalent in many low- and middle-income countries where it causes significant morbidity and mortality. Following the 2017 Cairo conference "Rheumatic Heart Disease: from Molecules to the Global Community," experts from 21 countries formulated an approach for addressing the problem of RHD: "The Cairo Accord on Rheumatic Heart Disease." The Accord attempts to set policy priorities for the eradication of acute rheumatic fever (ARF) and RHD and builds on a recent series of policy initiatives and calls to action. We present an update on the recommendations of the Cairo Accord and discuss recent progress toward the eradication of RHD, including contributions from our own Aswan Rheumatic Heart Disease Registry (ARGI).

Heart failure can affect everyone: the ESC Geoffrey Rose lecture

The principle of 'sick individuals vs. sick population', a concept pioneered by Geoffrey Rose 35 years ago, is particularly applicable to heart failure (HF). This perspective article summarizes and expands on the Geoffrey Rose lecture given at the European Society of Cardiology meeting held in conjunction with the World Congress of Cardiology, in Paris, 2019. This article focuses on the fact that, clearly, HF not only affects a large spectrum of the population globally, but it occurs in all ages and equally in both genders. Heart failure, in most parts of the world, is clearly not a disease of the elderly. There are multiple and complex pathways leading to HF which include various risk factors (including communicable diseases and exposure to indoor and environmental pollutants), poverty and overcrowding, as well as sub-optimal access to health care systems due to socioeconomic inequities. Reflecting on Geoffrey Rose's concept 35 years later motivates us to confront our global responsibility to address the population distribution of risk factors more effectively, instead of focusing solely on interventions that target high-risk individuals.

In Search of the Holy Grail: A Specific Diagnostic Test for Rheumatic Fever

Current diagnosis of Acute Rheumatic Fever and Rheumatic Heart Disease (ARF/RHD) relies on a battery of clinical observations aided by technologically advanced diagnostic tools and non-specific laboratory tests. The laboratory-based assays fall into two categories: those that (1) detect "evidence of preceding streptococcal infections" (ASOT, anti-DNAse B, isolation of the Group A Streptococcus from a throat swab) and (2) those that detect an ongoing inflammatory process (ESR and CRP). These laboratory tests are positive during any streptococcal infection and are non-specific for the diagnosis of ARF/RHD. Over the last few decades, we have accumulated considerable knowledge about streptococcal biology and the immunopathological mechanisms that contribute to the development, progression and exacerbation of ARF/RHD. Although our knowledge is incomplete and many more years will be devoted to understanding the exact molecular and cellular mechanisms involved in the spectrum of clinical manifestations of ARF/RHD, in this commentary we contend that there is sufficient understanding of the disease process that using currently available technologies it is possible to identify pathogen associated peptides and develop a specific test for ARF/RHD. It is our view that with collaboration and sharing of well-characterised serial blood samples from patients with ARF/RHD from different regions, antibody array technology and/or T-cell tetramers could be used to identify streptococcal peptides specific to ARF/RHD. The availability of an appropriate animal model for this uniquely human disease can further facilitate the determination as to whether these peptides are pathognomonic. Identification of such peptides will also facilitate testing of potential anti-streptococcal vaccines for safety and avoid potential candidates that may pre-dispose potential vaccine recipients to adverse outcomes. Such peptides can also be readily incorporated into a universally affordable point of care device for both primary and tertiary care.

The role of causal knowledge in stigma considerations in African genomics research: Views of South African Xhosa people

INTRODUCTION

Advances in genomics research have raised several ethical concerns. One concern is the potential impact of genomics research on stigma experienced by people affected by a disease. Studies have found that the type of illness as well as disease causal beliefs impact on the relation between genetic attribution and stigma. This study explored the potential impact of genetic attribution of disease on stigma among Xhosa people with Rheumatic Heart Disease (RHD).

METHODS

Study participants were 46 Xhosa people with RHD living in the Western Cape Province of South Africa. Using video vignettes in 7 focus group discussions we explored whether and how genetic attribution may impact on disease-stigma. Vignettes introduced participants to non-genetic and genetic causal explanations and were followed-up with a series of open-ended questions eliciting their perceptions of non-genetic disease causes as well as genetic causation and its impact on internalised stigma.

RESULTS

This study found that Xhosa people with RHD have a general understanding of genetics and genetic attribution for disease. Additionally, and not withstanding their genetic knowledge, these participants hold multiple disease causal beliefs including genetic, infectious disease, psychosocial, behavioural and cultural explanations. While there was evidence of internalised stigma experiences among participants, these appeared not to be related to a genetic attribution to the disease.

DISCUSSION

The findings of this study provide clues as to why it is unlikely that a genetic conceptualisation of disease impacts internalised stigma experiences of Xhosa people. The causal explanations provided by participants reflect their cultural understandings and their context, namely, living in low-income and poverty-stricken environments. Divergence in these findings from much of the evidence from high-income countries emphasises that context matters when considering the impact of genetic attribution on stigma and caution against generalising findings from one part of the globe to another.

The Genetic Control of the Rheumatic Heart: Closing the Genotype-Phenotype Gap

Rheumatic heart disease (RHD) is a heritable inflammatory condition characterized by carditis, arthritis, and systemic disease. Although remaining neglected, the last 3 years has seen some promising advances in RHD research. Whilst it is clear that RHD can be triggered by recurrent group A streptococcal infections, the mechanisms driving clinical progression are still poorly understood. This review summarizes our current understanding of the genetics implicated in this process and the genetic determinants that predispose some people to RHD. The evidence demonstrating the importance of individual cell types and cellular states in delineating causal genetic variants is discussed, highlighting phenotype/genotype correlations where possible. Genetic fine mapping and functional studies in extreme phenotypes, together with large-scale omics studies including genomics, transcriptomics, epigenomics, and metabolomics, are expected to provide new information not only on RHD but also on the mechanisms of other autoimmune diseases and facilitate future clinical translation.

Time to peak bilirubin concentration and advanced AKI were associated with increased mortality in rheumatic heart valve replacement surgery patients with severe postoperative hyperbilirubinemia: a retrospective cohort study

BACKGROUND

Hyperbilirubinemia after heart valve surgery (HVS) with cardiopulmonary bypass is frequently observed and associated with worse outcomes. We investigated the characteristics and prognosis of patients with severe hyperbilirubinemia after HVS for rheumatic heart disease (RHD) to identify the clinical outcomes and potential risk factors.

METHODS

Between 2015 and 2018, patients who underwent HVS in the cardiac surgery intensive care unit of our hospital were retrospectively screened. Risk factors for acute kidney injury (AKI), the requirement for continuous renal replacement therapy (CRRT), and in-hospital and long-term mortality were identified by univariate and multivariate analyses. The patient survival proportion was graphically presented with the Kaplan-Meier method.

RESULTS

A total of 149 patients who underwent HVS for RHD and had severe postoperative hyperbilirubinemia were included. Of the included patients, 80.5% developed postoperative AKI, and 18.1% required CRRT. The in-hospital mortality was 30.2%. Backward logistic regression analysis showed that the time to peak TB concentration (odds ratio [OR] 1.557, 95% confidence interval [CI] 1.259-1.926; P < 0.001) and advanced AKI (stage 2 and 3 AKI) (OR 19.408, 95% CI 6.553-57.482; P < 0.001) were independent predictors for in-hospital mortality. The cutoff value of the time to peak TB levels for predicting in-hospital mortality was 5 postoperative days.

CONCLUSIONS

Severe postoperative hyperbilirubinemia is a life-threatening complication in patients who undergo HVS for RHD. Patients whose bilirubin levels continued to increase past the 5th postoperative day and who had advanced AKI (stages 2 and 3) were associated with a higher risk of mortality.

Rheumatic heart disease: A review of the current status of global research activity

Rheumatic heart disease (RHD) is a serious and long-term consequence of acute rheumatic fever (ARF), an autoimmune sequela of a mucosal infection by Streptococcus pyogenes (Group A Streptococcus, Strep A). The pathogenesis of ARF and RHD is complex and not fully understood but involves host and bacterial factors, molecular mimicry, and aberrant host innate and adaptive immune responses that result in loss of self-tolerance and subsequent cross-reactivity with host tissues. RHD is entirely preventable yet claims an estimated 320 000 lives annually. The major burden of disease is carried by developing nations and Indigenous populations within developed nations, including Australia. This review will focus on the epidemiology, pathogenesis and treatment of ARF and RHD in Australia, where: streptococcal pyoderma, rather than streptococcal pharyngitis, and Group C and Group G Streptococcus, have been implicated as antecedents to ARF; the rates of RHD in remote Indigenous communities are persistently among the highest in the world; government register-based programs coordinate disease screening and delivery of prophylaxis with variable success; and researchers are making significant progress in the development of a broad-spectrum vaccine against Strep A.

How accurate is the diagnosis of rheumatic fever in Egypt? Data from the national rheumatic heart disease prevention and control program (2006-2018)

Rheumatic heart disease (RHD) as a chronic sequela of repeated episodes of acute rheumatic fever (ARF), remains a cause of cardiac morbidity in Egypt although it is given full attention through a national RHD prevention and control program. The present report reviews our experience with subjects presenting with ARF or its sequelae in a single RHD centre and describes the disease pattern over the last decade. A cross-sectional study was conducted in El-Mahalla RHD centre between 2006 and 2018. A total of 17014 individual were enrolled and evaluated. Diagnosis ARF was based on the 2015 revised Jones criteria and RHD was ruled in by echocardiography. The majority of the screened subjects were female (63.2%), in the age group 5-15 years (64.6%), rural residents (61.2%), had primary education (43.0%), and of low socioeconomic standard (50.2%). The total percentage of cases presenting with ARF sequelae was 29.3% [carditis/RHD (10.8%), rheumatic arthritis (Rh.A) (14.9%), and Sydenham's chorea (0.05%)]. Noticeably, 72% were free of any cardiac insult, of which 37.7% were victims of misdiagnoses made elsewhere by untrained practitioners who prescribed for them long term injectable long-acting penicillin [Benzathine Penicillin G (BPG)] without need. About 54% of the study cohort reported the occurrence of recurrent attacks of tonsillitis of which 65.2% underwent tonsillectomy. Among those who experienced tonsillectomy and/or received BPG in the past, 14.5% and 22.3% respectively had eventually developed RHD. Screening of family members of some RHD cases who needed cardiac surgery revealed 20.7% with undiagnosed ARF sequalae [RHD (56.0%) and Rh.A (52.2%)]. Upon the follow-up of RHD cases, 1.2% had improved, 98.4% were stable and 0.4% had their heart condition deteriorated. Misdiagnosis of ARF or its sequelae and poor compliance with BPG use may affect efforts being exerted to curtail the disease. Updating national guidelines, capacity building, and reliance on appropriate investigations should be emphasized. Since the genetic basis of RHD is literally confirmed, a family history of RHD warrants screening of all family members for early detection of the disease.

The Human Leukocyte Antigen Locus and Rheumatic Heart Disease Susceptibility in South Asians and Europeans

Rheumatic heart disease (RHD), an autoinflammatory heart disease, was recently declared a global health priority by the World Health Organization. Here we report a genome-wide association study (GWAS) of RHD susceptibility in 1,163 South Asians (672 cases; 491 controls) recruited in India and Fiji. We analysed directly obtained and imputed genotypes, and followed-up associated loci in 1,459 Europeans (150 cases; 1,309 controls) from the UK Biobank study. We identify a novel susceptibility signal in the class III region of the human leukocyte antigen (HLA) complex in the South Asian dataset that clearly replicates in the Europeans (rs201026476; combined odds ratio 1.81, 95% confidence intervals 1.51-2.18, P = 3.48×10-10). Importantly, this signal remains despite conditioning on the lead class I and class II variants (P = 0.00033). These findings suggest the class III region is a key determinant of RHD susceptibility offering important new insight into pathogenesis while partly explaining the inconsistency of earlier reports.

COVID-19 in Children: A Review and Parallels to Other Hyperinflammatory Syndromes

During the COVID-19 pandemic, children have had markedly different clinical presentations and outcomes compared to adults. In the acute phase of infection, younger children are relatively spared the severe consequences reported in adults. Yet, they are uniquely susceptible to the newly described Multisystem Inflammatory Syndrome in Children (MIS-C). This may result from the developmental "immunodeficiency" resulting from a Th2 polarization that starts in utero and is maintained for most of the first decade of life. MIS-C may be due to IgA complexes in a Th2 environment or a Th1-like response to COVID-19 antigens that developed slowly. Alternatively, MIS-C may occur in vulnerable hosts with genetic susceptibilities in other immune and non-immune pathways. Herein, we present a brief overview of the host immune response, virologic and genetic factors, and comparable inflammatory syndromes that may explain the pathophysiology leading to drastic differences in clinical presentation and outcomes of COVID-19 between children and adults.