Environmental factors and rheumatic heart disease in Fiji

Tertiary prevention and treatment of rheumatic heart disease: a National Heart, Lung, and Blood Institute working group summary

Although entirely preventable, rheumatic heart disease (RHD), a disease of poverty and social disadvantage resulting in high morbidity and mortality, remains an ever-present burden in low-income and middle-income countries (LMICs) and rural, remote, marginalised and disenfranchised populations within high-income countries. In late 2021, the National Heart, Lung, and Blood Institute convened a workshop to explore the current state of science, to identify basic science and clinical research priorities to support RHD eradication efforts worldwide. This was done through the inclusion of multidisciplinary global experts, including cardiovascular and non-cardiovascular specialists as well as health policy and health economics experts, many of whom also represented or closely worked with patient-family organisations and local governments. This report summarises findings from one of the four working groups, the Tertiary Prevention Working Group, that was charged with assessing the management of late complications of RHD, including surgical interventions for patients with RHD. Due to the high prevalence of RHD in LMICs, particular emphasis was made on gaining a better understanding of needs in the field from the perspectives of the patient, community, provider, health system and policy-maker. We outline priorities to support the development, and implementation of accessible, affordable and sustainable interventions in low-resource settings to manage RHD and related complications. These priorities and other interventions need to be adapted to and driven by local contexts and integrated into health systems to best meet the needs of local communities.

Machine learning methods for predicting major types of rheumatic heart diseases in children of Southern Punjab, Pakistan

Objective

Rheumatic heart disease (RHD) is a major health problem in the world, particularly in developing countries. This study aimed to predict mitral regurgitation (MR) and mitral stenosis (MS) RHD among children with RHD.

Methodology

Data was collected from the Pediatric Cardiology Department at Chaudhry Pervaiz Elahi Institute of Cardiology Multan, Pakistan from March to October 2019. A sample of 561 children aged 4–14 years, who were diagnosed with RHD of either MR or MS, were recruited from the hospital’s outpatient department. The presence of multivariate outliers was detected, and different machine learning methods, including subset logistic regression, subset logistic regression after deletion, stepwise winsorized logistic regression, robust logistic regression, subset deep neural network, and random forest models were compared using the area under receiver operating characteristics (ROC) curve, sensitivity, and specificity. Parsimony was also considered in model selection.

Results

Out of 561 patients in this study, 75.94% had RHD MR and 24.06% had RHD MS. The average age of study participants was 9.19 ± 2.45 years and of them 55.43% were male. Among the male participants, 58.6 and 45.2% had MR and MS, respectively; and among female participants, those were 70.4 and 29.6%, respectively. Subset logistic regression after deletion appeared as competitive with a discrimination power of 90.1% [95% CI 0.818–0.983]. The sensitivity and specificity of this model were 85.1 and 70.6%.

Conclusion

The best predictive model was subset logistic regression after deletion. The predicted method will be used in the decision-making process, which helps early diagnosis of the disease and leads to prevention. The study findings provide the proper guideline for earlier diagnosis of the RHD MR and MS cases among children with RHD in Pakistan.

Breastfeeding does not protect against the development of carditis in children with acute rheumatic fever

INTRODUCTION

Acute rheumatic fever is an autoimmune disease that develops due to streptococcal infection. The positive effect of breastfeeding on the development of the child's immune system is well documented. In this study, we aimed to investigate the effect of breast milk intake period on the development of carditis.

MATERIALS AND METHODS

Patients (n: 182) who were diagnosed with acute rheumatic fever between 2010 and 2019 were enrolled in the study. The patients were divided into groups according to carditis development. The demographic, socio-economic, and breastfeeding data were compared between groups.

RESULTS

The mean age of the patients was 10.5 ± 3.4, and 43.4 % (n: 79) of them were female. Independent predictors of the development of carditis in the first acute rheumatic fever episode were the number of children at home (OR: 1.773, CI 95%: 1.105, 2.845; p: 0.018) and breast milk intake less than 6 months (OR: 0.404, CI 95%: 0.174, 0.934; p: 0.034). Independent predictors of the development of carditis in any of the acute rheumatic fever episodes were the number of children at home (OR: 1.858, CI 95%: 1.100, 3.137; p: 0.021) and female gender (OR: 3.504, CI 95%: 1.227, 10.008; p: 0.019). The only independently predictor of the development of chorea during acute rheumatic fever was female gender (OR: 3.801, CI 95%: 1.463, 9.874; p: 0.006).

CONCLUSION

Although the occurrence of carditis is less common during the first acute rheumatic fever attack in patients with breast milk intake less than six months, this advantage is lost in recurrent attacks. This study showed that breast milk does not have a negative effect on acute rheumatic fever carditis.

Pediatric Rheumatic Heart Disease in a Middle-Income Country: A Population-Based Study

INTRODUCTION

Rheumatic heart disease (RHD), a debilitating complication from rheumatic fever, remains a problem in low- and middle-income countries. This study describes the incidence, prevalence, modifiable risk factors for severe RHD and immediate outcome of pediatric RHD.

METHODS

This population-based and observational cohort study reviewed pediatric RHD patients (0-18 years) from the Sabah Pediatric Rheumatic Heart Registry from 2015 till 2018.

RESULTS

A total of 188 RHD were reviewed with 120 new cases. The incidence of RHD is 2.19 [95% confidence interval (CI): 1.83-2.61] per 100 000 population, with a rising trend over time. Meanwhile, the prevalence of RHD was 13.78 (95% CI: 11.92-15.86) per 100 000 pediatric population. The majority of patients were from indigenous groups (59.0%), male (56.4%) with a mean age of 14.3 (3.31) years. About 77.9% had the lowest household income, and a significant proportion lived in overcrowded conditions. At diagnosis, 59% were diagnosed with severe RHD. There is heightened risk but no statistical significance between modifiable factors (low weight and height percentile at diagnosis, lowest income group, renting a house, overcrowding and healthcare access of more than 5 km) with severe RHD. Severe RHD is significantly associated with risk for intervention (p = 0.016). Sixteen (13.8%) patients required surgical intervention. About 97.6% of patients were on intramuscular benzathine penicillin G with 84.5% compliance.

CONCLUSION

The rising prevalence and incidence of pediatric RHD in Sabah, with the most being severe RHD at diagnosis, necessitates the development of an echocardiographic screening and a comprehensive national disease program.

Relationship between Environmental Factors and Rheumatic Heart Disease

Background. Rheumatic fever (RF) and rheumatic heart disease (RHD) are the most common acquired heart diseases in children. Environmental factors have been reported to play an important role in RHD’s prevalence Aim. The main purpose of this study is to assess the associations between environmental factors and RHD in children. Methods. A case control study was conducted in the Department of Child Health, Haji Adam Malik Hospital from April to June 2017. The case group consisted of children aged 5-18 years with RHD while control group consisted of healthy children. Demographic, anthropometric, and laboratory data were collected along with environmental factors. Statistical analysis was done using Statistical Product and Service Solution (SPSS). A P value of <0,05 with 95% confidence interval was considered significant. Results. A total of 39 children were enrolled in each group. Subjects’ father who only went to elementary and junior high school had a higher risk of having children with RHD (OR 28; p = 0.032 and OR 15.75; p = 0.011, respectively). Subjects’ mother who only went to junior high school had 7 times higher risk of having children with RHD (p = 0.026). Low monthly income increased the risk of RHD (OR 3,68; p = 0,009). Tap water usage, meat consumption more than once per week, and feasibility to buy clothes >1 pair per year decreased the risk of RHD at 0,31 (p = 0,013), 0,3 (p = 0,016), and 0,04 times (p <0,001) respectively. Conclusion. Parent’s education, monthly family income, water source, frequency of meat consumption, and feasibility to buy clothes are related to RHD in children.

Raising awareness for rheumatic mitral valve disease

Rheumatic heart disease (RHD) is a major burden in low- to mid-income countries, where each year it accounts for over a million premature deaths associated with severe valve disease. Life-saving valve replacement procedures are not available to the majority of affected RHD patients, contributing to an increased risk of death in young adults and creating a devastating impact. In December 2017, a group of representatives of major cardiothoracic societies and industry, discussed the plight of the millions of patients who suffer from RHD. A comprehensive solution based on this global partnership was outlined in "The Cape Town Declaration on Access to Cardiac Surgery in the Developing World". The key challenge in controlling RHD is related to identification and removal of barriers to the translation of existing knowledge into policy, programs, and practice to provide high-quality care for patients with RHD. This review provides an overview on RHD by emphasizing the disease medical and economic burdens worldwide, risk factors, recent advance for early disease detection, and overall preventive strategies.

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.

Screening Rheumatic Heart Disease in 1530 New Caledonian Adolescents

BACKGROUND

In New Caledonia, a South Pacific archipelago whose inhabitants comprise Melanesians, Europeans/whites, Wallisians, Futunans, Polynesians, and Asians, the prevalence of rheumatic heart disease (RHD) is 0.9% to 1% at ages 9 and 10. It could be higher at the age of 16, but this remains to be verified.

METHODS AND RESULTS

A total of 1530 Melanesian, Métis, white, Wallisian, Futunan, Polynesian, and Asian adolescents benefited from a transthoracic echocardiogram. Definite or borderline RHD, nonrheumatic valve lesions, congenital heart defects, family and personal history of acute rheumatic fever, and socioeconomic factors were collected. The prevalence of cardiac abnormalities was 8.1%, made up of 4.1% RHD including 2.4% definite and 1.7% borderline RHD, 1.7% nonrheumatic valve lesions, and 2.3% congenital anomalies. In whites and Asians, there were no cases of RHD. RHD was higher in the Wallisian, Futunan, and Polynesian group (7.6%) when compared with Melanesians (5.3%) and Métis (2.9%). The number of nonrheumatic valve lesions was not statistically different in the different ethnicities. The prevalence of RHD was higher in adolescents with a personal history of acute rheumatic fever, in those living in overcrowded conditions, and in those whose parents were unemployed or had low‐income occupations, such as the farmers or manual workers.

CONCLUSIONS

RHD was 4 times higher in adolescents at age 16 than at ages 9 and 10 (4.1% versus 0.9%–1%). No cases of RHD were observed in whites and Asians. The determining factors were history of acute rheumatic fever and socioeconomic factors.

Genetic variants in rheumatic fever and rheumatic heart disease

Genetic association studies in rheumatic heart disease (RHD) have the potential to contribute toward our understanding of the pathogenetic mechanism, and may shed light on controversies about RHD etiology. Furthermore, genetic association studies may uncover biomarkers that can be used to identify susceptible individuals, and contribute toward developing vaccine and novel therapeutic targets. Genetic predisposition to rheumatic fever and RHD has been hypothesized by findings from familial studies and observed associations between genes located in the human leukocyte antigens on chromosome 6p21.3 and elsewhere in the genome. We sought to summarize, from published Genetic association studies in RHD, evidence on genetic variants implicated in RHD susceptibility. Using HuGENet™ systematic review methods, we evaluated 66 studies reporting on 42 genes. Existing meta-analyses of candidate gene studies suggest that TGF-β1 [rs1800469], and IL-1β [rs2853550] single nucleotide polymorphisms (SNPs) contribute to susceptibility to RHD, whereas the TNF-α [rs1800629 and rs361525], TGF-β1 [rs1800470 and rs4803457], IL-6 [rs1800795], IL-10 [rs1800896] were not associated with RHD. However, candidate gene studies in RF/RHD are relatively small, thus lacking statistical power to identify reliable and reproducible findings, emphasizing the need for large-scale multicenter studies with different populations.

Risk Factors for Acute Rheumatic Fever: Literature Review and Protocol for a Case-Control Study in New Zealand

Acute rheumatic fever (ARF) and its sequela, rheumatic heart disease (RHD), have largely disappeared from high-income countries. However, in New Zealand (NZ), rates remain unacceptably high in indigenous Māori and Pacific populations. The goal of this study is to identify potentially modifiable risk factors for ARF to support effective disease prevention policies and programmes. A case-control design is used. Cases are those meeting the standard NZ case-definition for ARF, recruited within four weeks of hospitalisation for a first episode of ARF, aged less than 20 years, and residing in the North Island of NZ. This study aims to recruit at least 120 cases and 360 controls matched by age, ethnicity, gender, deprivation, district, and time period. For data collection, a comprehensive pre-tested questionnaire focussed on exposures during the four weeks prior to illness or interview will be used. Linked data include previous hospitalisations, dental records, and school characteristics. Specimen collection includes a throat swab (Group A Streptococcus), a nasal swab (Staphylococcus aureus), blood (vitamin D, ferritin, DNA for genetic testing, immune-profiling), and head hair (nicotine). A major strength of this study is its comprehensive focus covering organism, host and environmental factors. Having closely matched controls enables the examination of a wide range of specific environmental risk factors.

T cell subsets: an integral component in pathogenesis of rheumatic heart disease

Acute rheumatic fever (ARF) is a consequence of pharyngeal infection of group A streptococcal (GAS) infection. Carditis is the most common manifestation of ARF which occurs in 30-45% of the susceptible individuals. Overlooked ARF cases might further progress towards rheumatic heart disease (RHD) in susceptible individuals, which ultimately leads to permanent heart valve damage. Molecular mimicry between streptococcal antigens and human proteins is the most widely accepted theory to describe the pathogenesis of RHD. In the recent past, various subsets of T cells have been reported to play an imperative role in the pathogenesis of RHD. Alterations in various T cell subsets, viz. Th1, Th2, Th17, and Treg cells, and their signature cytokines influence the immune responses and are associated with pathogenesis of RHD. Association of other T cell subsets (Th3, Th9, Th22, and T_FH) is not defined in context of RHD. Several investigations have confirmed the up-regulation of adhesion molecules and thus infiltration of T cells into the heart tissues. T cells secrete both Th type 1 and type 2 cytokines and these auto-reactive T cells play a key role in progression of heart valve damage. In this review, we are going to discuss about the role of T cell subsets and their corresponding cytokines in the pathogenesis of RHD.

A hospital-based study of socioeconomic status and clinical spectrum of rheumatic heart disease patients of Assam, North-East India

Objective

The aim of this study was to assess the impact of socioeconomic factors in increased prevalence of rheumatic heart disease and its clinical spectrum in Assam, North-East India.

Method

A case–control questionnaire-based study of 100 echocardiography confirmed rheumatic heart disease cases with age- and sex-matched healthy controls from Assam medical college and hospital in Dibrugarh, Assam was conducted.

Results

There was a trend toward increased risk of rheumatic heart disease and its clinical spectrum with respect to low socioeconomic status. Three parameters were found to be statistically significant in posing increased risk towards rheumatic heart disease: rural dwelling location ( p < 0.0001, odds ratio (OR) 4.1, 95% confidence interval (CI = 2.29−7.45), low monthly income ( p < 0.001, OR=9.5, 95% CI = 4.99−18.1) and education status ( p < 0.05, OR=9.5, 95% CI = 1.866). Out of the severe cases of mitral stenosis, mitral regurgitation and aortic regurgitation, 69.6%, 58.3% and 34% patients were of low socioeconomic status.

Conclusion

Socioeconomic factors can be of significant importance in increased prevalence of rheumatic heart disease and might also influence the clinical spectrum of the disease. Increased awareness and up-gradation of socioeconomic status might ameliorate the prevalence of rheumatic heart disease.

The role of social determinants of health in the risk and prevention of group A streptococcal infection, acute rheumatic fever and rheumatic heart disease: A systematic review

Background

Rheumatic heart disease (RHD) poses a major disease burden among disadvantaged populations globally. It results from acute rheumatic fever (ARF), a complication of Group A Streptococcal (GAS) infection. These conditions are acknowledged as diseases of poverty, however the role of specific social and environmental factors in GAS infection and progression to ARF/RHD is not well understood. The aim of this systematic review was to determine the association between social determinants of health and GAS infection, ARF and RHD, and the effect of interventions targeting these.

Methodology

We conducted a systematic literature review using PubMed, the Cochrane Library and Embase. Observational and experimental studies that measured: crowding, dwelling characteristics, education, employment, income, nutrition, or socioeconomic status and the relationship with GAS infection, ARF or RHD were included. Findings for each factor were assessed against the Bradford Hill criteria for evidence of causation. Study quality was assessed using a standardised tool.

Principle findings

1,164 publications were identified. 90 met inclusion criteria, comprising 91 individual studies. 49 (50.5%) were poor quality in relation to the specific study question. The proportion of studies reporting significant associations between socioeconomic determinants and risk of GAS infection was 57.1%, and with ARF/RHD was 50%. Crowding was the most assessed factor (14 studies with GAS infection, 36 studies with ARF/RHD) followed by socioeconomic status (6 and 36 respectively). The majority of studies assessing crowding, dwelling characteristics, education and employment status of parents or cases, and nutrition, reported a positive association with risk of GAS infection, ARF or RHD. Crowding and socioeconomic status satisfactorily met the criteria of a causal association. There was substantial heterogeneity across all key study aspects.

Conclusion

The extensive literature examining the role of social determinants in GAS infection, ARF and RHD risk lacks quality. Most were observational, not interventional. Crowding as a cause of GAS infection and ARF/RHD presents a practical target for prevention actions.

Rates of rheumatic heart disease (RHD) are high in disadvantaged populations globally. It results from acute rheumatic fever (ARF), a complication of Group A Streptococcal (GAS) infection. These are described as diseases of poverty, but exactly what components of poverty promote them has been unclear. The aim of this review was to find what specific social and environmental factors are associated with GAS infection, ARF and RHD, and if actions targeting these can reduce disease rates. We did a search of published literature and found 90 relevant articles. Many supported an association between GAS infection, ARF or RHD and crowding, dwelling characteristics, low education level and employment status, poor nutrition and low social class. There was enough evidence to show that crowding and socioeconomic disadvantage increase the risk of GAS infection and ARF/RHD. However, most studies were of fair to poor quality in their ability to answer the research question, and there was little interventional research. This may relate to challenges inherent in intervening to change social determinants of health, but may also suggest lesser research attention to health issues affecting disadvantaged populations. The association between crowding and disease risk strongly supports initiatives to reduce crowding. This should become a key target for ARF and RHD prevention.

Using preceding hospital admissions to identify children at risk of developing acute rheumatic fever

AIMS

New Zealand (NZ) Māori and Pacific children have high rates of acute rheumatic fever (ARF). Around 150 new cases arise each year. As part of the national ARF prevention programme, funding is available to improve housing. To obtain maximum benefit from interventions, an effective tool is needed for targeting high-risk children. This study aimed to assess the effectiveness of using hospitalisations for identifying children at risk of subsequent ARF.

METHODS

Three potentially avoidable hospitalisation (PAH) groups were investigated, including diseases thought to be influenced by housing. All were developed using expert opinion or systematic reviews. These were: (i) the PAH conditions associated with the housing environment (PAHHE) group; (ii) the Crowding group; and (iii) the Ministry of Health (MoH) group. We analysed NZ public hospital discharge data (2000-2014). The prevalence of ARF among patients hospitalised in each group was calculated to estimate sensitivity and potential effectiveness. The number needed to screen (NNS) to identify one ARF case was estimated as a measure of efficiency.

RESULTS

Nearly one-third of ARF patients experienced a PAH as children (before developing ARF). Sensitivity for detecting future ARF ranged from <5% (MoH group) to 27% (PAHHE group). NNS ranged from 502.4 (PAHHE) to 707.5 (MoH).

CONCLUSIONS

Because ARF is relatively rare, observing hospitalisations is not particularly efficient for targeting prevention activities for this condition alone. However, housing interventions are likely to improve multiple outcomes; thus, the hospital setting is still useful for identifying at-risk children who could benefit from such programmes.

Acute rheumatic fever and exposure to poor housing conditions in New Zealand: A descriptive study

AIM

Acute rheumatic fever (ARF) is an important public health problem in low- and middle-income countries and in certain populations in high-income countries. Indigenous Australians, and New Zealand Māori and Pacific people, have incidence rates among the highest in the world. We aimed to investigate ARF cases' housing conditions and sore throat treatment to identify opportunities for improving ARF prevention in New Zealand.

METHODS

Recently diagnosed cases and their care givers were interviewed. Information was obtained about the cases' demographics, housing circumstances and conditions, and sore throat treatment preceding ARF.

RESULTS

We interviewed 55 cases. Most (75%) lived in rental housing and reported multiple measures of deprivation. Common exposures were household crowding (58%), bed-sharing (49%), dampness and mould (76%), cold (82%) and co-habiting with smokers (71%). Experiencing sore throat in the weeks before ARF was recalled by 62%, with 29% seeing a doctor or nurse and 13% of the total sample receiving antibiotics.

CONCLUSIONS

The environmental conditions reported could contribute to high group A Streptococcus transmission and susceptibility to infection, thus increasing ARF risk. Sore throat treatment has important limitations as an intervention, particularly as 38% of participants did not recall sore throat preceding the diagnosis. The results support the need to improve rental housing. Interventions promoting minimum enforceable standards in social housing and private rental sectors (such as a housing warrant of fitness) could support these changes. A rigorous investigation, such as a case control study, is needed to explore risk factors further.

An epidemiological study to assess the true incidence and prevalence of rheumatic heart disease and acute rheumatic fever in New Caledonian school children

AIM

To provide in New Caledonian school children (i) the prevalence of rheumatic heart disease (RHD) detected by annual screening program using new World Heart Federation diagnostic criteria; (ii) the point prevalence of acute rheumatic fever (ARF); and (iii) to investigate socio-demographic risk factors associated with RHD.

METHODS

This study linked data from national ARF/RHD programs by combining ARF incidence data from the register with RHD prevalence data from echocardiographic screening data for a single age year of the population for overall point prevalence ARF/RHD rates. For the analysis, cases of echocardiographic detection of RHD are presumed to be synonymous with undiagnosed ARF. All results were weighted to minimise the bias introduced from absent pupils of each annual screening program. Incidence and prevalence were age-standardised to the WHO World Standard Population. Each 2013 cumulative prevalence of definite and borderline RHD was studied using a multivariate logistic regression adjusted for socio-demographic factors.

RESULTS

The overall age-standardised incidence of clinical and undiagnosed ARF (i.e. echocardiographic-detected RHD) was combined as point prevalence and estimated to be 99/10 000 cases in 2012 and 114/10 000 cases in 2013. This included 40/10 000 prevalent cases of asymptomatic RHD detected by screening each year. Being Melanesian, OR 23.2 (95% CI: 3.4-157.3), or Polynesian, OR 21.5 (95% CI: 2.9-157.7), was associated with a higher prevalence of having definite RHD compared with being Caucasian. Being a girl was associated with a higher risk of having borderline RHD, OR 1.9 (95% CI: 1.03-3.3).

CONCLUSION

Without echocardiographic screening, ARF/RHD burden is substantially underestimated.

IL10 Promoter Polymorphisms are Associated with Rheumatic Heart Disease in Saudi Arabian Patients

Rheumatic heart disease (RHD) is an inflammatory disease that develops following streptococcal infections. IL10 helps to balance immune responses to pathogens. IL10 polymorphisms have been associated with RHD, although results remain inconclusive. Our aim was to investigate the association between IL10 polymorphisms and RHD in Saudi Arabian patients. IL10 promoter polymorphisms (-1082A/G, -829C/T, and -592C/A) were genotyped in 118 RHD patients and 200 matched controls using the TaqMan allelic discrimination assay. There was a significant difference in IL10-1082 genotype frequency between patients and controls (p = 0.01). -1082G allele carriage (GG+GA vs AA) and the (-1082, -819, -592) GCC haplotype carriage were associated with an increased risk of RHD (p = 0.004, OR 2.1, 95% CIs 1.7-3.4 and p = 0.004, OR 2, 95% CIs 1.3-3.4, respectively). The ACC haplotype was associated with a decrease in RHD risk (p = 0.015, OR 0.6, 95% CIs 0.4-0.9). IL10 promoter polymorphisms may play an important role in the development of RHD and provide an opportunity for therapeutic stratification.

Association of angiotensin I-converting enzyme gene insertion/deletion polymorphism with rheumatic heart disease in Indian population and meta-analysis

Rheumatic heart disease (RHD) is one of the most severe consequences of rheumatic fever. It has been suggested that angiotensin I-converting enzyme (ACE) may be involved in the increased valvular fibrosis and calcification in the pathogenesis of RHD. We conducted a case-control study to look for association of ACE I/D polymorphism with RHD in Indian population. The study incorporated 300 patients (170 males and 130 females) with RHD, and 200 controls (118 males and 82 females). We also subgrouped RHD patients into mitral valve lesion (MVL) and combined valve lesion (CVL). ACE I/D polymorphism was identified using polymerase chain reaction method. We also performed a meta-analysis of three published studies and the present study (636 RHD cases and 533 controls) to evaluate the association between the ACE I/D polymorphisms and RHD risk. A significant difference in ACE ID and DD genotypes distribution between RHD cases (OR = 1.62, 95% CI = 1.11-2.36 and OR = 2.08, 95% CI = 1.02-4.15, respectively) and corresponding controls was observed. On comparing the ACE genotypes of MVL and CVL subgroups with controls, ID and DD genotypes were also significantly associated with CVL (FDR Pcorr = 0.009, OR = 2.19 and FDR Pcorr = 0.014, OR = 3.29, respectively). Meta-analysis also suggested association of the ACE D allele (FDR Pcorr = 0.036, OR-1.22, 95% CI 1.02-1.45) with RHD. In conclusion, ACE ID and DD genotypes are associated with an increased risk of RHD, particularly CVL. This suggests that the ACE I/D gene polymorphism may play an important role in the pathogenesis of RHD.

Socioeconomic and environmental risk factors among rheumatic heart disease patients in Uganda

BACKGROUND

Although low socioeconomic status, and environmental factors are known risk factors for rheumatic heart disease in other societies, risk factors for rheumatic heart disease remain less well described in Uganda.

AIMS AND OBJECTIVE

The objective of this study was to investigate the role of socio-economic and environmental factors in the pathogenesis of rheumatic heart disease in Ugandan patients.

METHODS

This was a case control study in which rheumatic heart disease cases and normal controls aged 5-60 years were recruited and investigated for socioeconomic and environmental risk factors such as income status, employment status, distance from the nearest health centre, number of people per house and space area per person.

RESULTS

486 participants (243 cases and 243 controls) took part in the study. Average age was 32.37+/-14.6 years for cases and 35.75+/-12.6 years for controls. At univariate level, Cases tended to be more overcrowded than controls; 8.0+/-3.0 versus 6.0+/-3.0 persons per house. Controls were better spaced at 25.2 square feet versus 16.9 for cases. More controls than cases were employed; 45.3% versus 21.1%. Controls lived closer to health centers than the cases; 4.8+/-3.8 versus 3.3+/-12.9 kilometers. At multivariate level, the odds of rheumatic heart disease was 1.7 times higher for unemployment status (OR = 1.7, 95% CI = 1.05-8.19) and 1.3 times higher for overcrowding (OR = 1.35, 95% CI = 1.1-1.56). There was interaction between overcrowding and longer distance from the nearest health centre (OR = 1.20, 95% CI = 1.05-1.42).

CONCLUSION

The major findings of this study were that there was a trend towards increased risk of rheumatic heart disease in association with overcrowding and unemployment. There was interaction between overcrowding and distance from the nearest health center, suggesting that the effect of overcrowding on the risk of acquiring rheumatic heart disease increases with every kilometer increase from the nearest health center.