Serial studies on the cellular immune response to streptococcal antigens in acute and convalescent rheumatic fever patients in Trinidad

Utility of Human Immune Responses to GAS Antigens as a Diagnostic Indicator for ARF: A Systematic Review

Background: Previous studies have established that streptococcal antibody titer is correlated with a diagnosis of acute rheumatic fever (ARF). However, results vary in the usefulness of GAS antibodies, particularly anti-streptolysin-O (ASO) and anti-DNase B, in confirming a recent GAS infection. Therefore, we sought to provide, from published studies, an evidence-based synthesis of the correlation of streptococcal serology to establish the usefulness of immunological data in aiding the diagnosis of ARF. These findings are anticipated to have implications where echocardiography is not freely available, especially where ARF is rampant. Methods: We conducted a comprehensive search across a number of databases. Applying a priori criteria, we selected articles reporting on studies, regardless of study design, that evaluate the levels of antibodies against GAS-specific antigens in ARF subjects against control values or a published standard. Data were extracted onto data extraction forms, captured electronically, and analyzed using Stata software. Risk of bias was assessed in included studies using the Newcastle-Ottawa Scale (NOS). Results and Conclusion: The search strategy yielded 534 studies, from which 24 met the inclusion criteria, reporting on evaluation of titers for SLO (n = 10), DNase B (n = 9), anti-streptokinase (ASK) (n = 3) amongst others. Elevation in titers was determined by comparison with controls and upper limit of normal (ULN) antibody values as determined in healthy individuals. Meta-analysis of case-controlled studies revealed moderate odds ratio (OR) correlations between ARF diagnosis and elevated titers for SLO (OR = 10.57; 95% CI, 3.36-33.29; 10 studies) and DNAse B (OR = 6.97; 95% CI, 2.99-16.27; 7 studies). While providing support for incorporating SLO and DNase B in the diagnosis of ARF, we present the following reflections: an elevation in SLO and DNase B levels are not consistently associated with an ARF diagnosis; increasing the number of GAS proteins in the test is warranted to improve sensitivity; paired (acute and convalescent) samples could provide a more accurate indication of a rising titer. Use of community-based controls as a standard is not a reliable marker by which to gauge recent GAS infection.

Molecular Mimicry, Autoimmunity, and Infection: The Cross-Reactive Antigens of Group A Streptococci and their Sequelae

The group A streptococci are associated with a group of diseases affecting the heart, brain, and joints that are collectively referred to as acute rheumatic fever. The streptococcal immune-mediated sequelae, including acute rheumatic fever, are due to antibody and cellular immune responses that target antigens in the heart and brain as well as the group A streptococcal cross-reactive antigens as reviewed in this article. The pathogenesis of acute rheumatic fever, rheumatic heart disease, Sydenham chorea, and other autoimmune sequelae is related to autoantibodies that are characteristic of autoimmune diseases and result from the immune responses against group A streptococcal infection by the host. The sharing of host and streptococcal epitopes leads to molecular mimicry between the streptococcal and host antigens that are recognized by the autoantibodies during the host response. This article elaborates on the discoveries that led to a better understanding of the pathogenesis of disease and provides an overview of the history and the most current thought about the immune responses against the host and streptococcal cross-reactive antigens in group A streptococcal sequelae.

Parameters indicative of persistence of valvular pathology at initial diagnosis in acute rheumatic carditis: the role of albumin and CD19 expression

OBJECTIVE

The aim of this study is to define the predictors of chronic carditis in patients with acute rheumatic carditis (ARC).

METHODS

Patients diagnosed with ARC between May 2010 and May 2011 were included in the study. Echocardiography, electrocardiography, lymphocyte subset analysis, acute phase reactants, plasma albumin levels, and antistreptolysin-O (ASO) tests were performed at initial presentation. The echocardiographic assessments were repeated at the sixth month of follow-up. The patients were divided into two groups according to persistence of valvular pathology at 6th month as Group 1 and Group 2, and all clinical and laboratory parameters at admission were compared between two groups of valvular involvement.

RESULTS

During the one-year study period, 22 patients had valvular disease. Seventeen (77.2%) patients showed regression in valvular pathology. An initial mild regurgitation disappeared in eight patients (36.3%). Among seven (31.8%) patients with moderate regurgitation initially, the regurgitation disappeared in three, and four patients improved to mild regurgitation. Two patients with a severe regurgitation initially improved to moderate regurgitation (9.1%). In five (22.8%) patients, the grade of regurgitation [moderate regurgitation in one (4.6%), and severe regurgitation in 4 (18.2%)] remained unchanged. The albumin level was significantly lower at diagnosis in Group 2 (2.6±0.48g/dL). Lymphocyte subset analysis showed a significant decrease in the CD8 percentage and a significant increase in CD19 percentage at diagnosis in Group 2 compared to Group 1.

CONCLUSION

The blood albumin level and the percentage of CD8 and CD19 (+) lymphocytes at diagnosis may help to predict chronic valvular disease risk in patients with acute rheumatic carditis.

Post-infectious group A streptococcal autoimmune syndromes and the heart

There is a pressing need to reduce the high global disease burden of rheumatic heart disease (RHD) and its harbinger, acute rheumatic fever (ARF). ARF is a classical example of an autoimmune syndrome and is of particular immunological interest because it follows a known antecedent infection with group A streptococcus (GAS). However, the poorly understood immunopathology of these post-infectious diseases means that, compared to much progress in other immune-mediated diseases, we still lack useful biomarkers, new therapies or an effective vaccine in ARF and RHD. Here, we summarise recent literature on the complex interaction between GAS and the human host that culminates in ARF and the subsequent development of RHD. We contrast ARF with other post-infectious streptococcal immune syndromes - post-streptococcal glomerulonephritis (PSGN) and the still controversial paediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS), in order to highlight the potential significance of variations in the host immune response to GAS. We discuss a model for the pathogenesis of ARF and RHD in terms of current immunological concepts and the potential for application of in depth "omics" technologies to these ancient scourges.

Immune responsiveness during disease progression from acute rheumatic fever to chronic rheumatic heart disease

Streptococcus pyogenes causes pharyngitis in school age children, which if left untreated causes acute rheumatic fever (ARF) that later progress toward rheumatic heart disease (RHD). The pathogenesis of this disease and its progression as post infectious squeal is not well understood. In this study, percentages of CD4(+) and CD8(+) T-cells were compared among patients of ARF, RHD and Chronic RHD using flow cytometer. The production of Th1/Th2 cytokines from serum and endothelial cells of damaged and normal heart valves was also analyzed using flow cytometer. Results showed an inverse proportion of CD4(+) and CD8(+) T-cell numbers in ARF and RHD patients. Cytokine assay demonstrated a switch-over from Th1 to Th2 type, as the disease progressed. We observed significantly high IL-6 in ARF patients and high TNF-α in early RHD patients which allowed us to construct a hypothesis, that, during initial infection phase, lot of antibodies are produced (via IL-6) and TNF-α has a role in disease progression and tissue damage during RHD phase.

Understanding rheumatic fever

Through a comprehensive review of the recent findings on rheumatic fever, we intend to propose a new physiopathologic model for this disease. A Medline search was performed for all articles containing the terms rheumatic fever or rheumatic heart disease in title or abstract from 1970 to 2011. Best evidence qualitative technique was used to select the most relevant. The scientific interest on rheumatic fever has notably diminished throughout the twentieth century as evidenced by the comparison of the proportion of articles in which RF was a subject in 1950 (0.26%) and today (0.03%) [Pubmed]. However, RF remains a major medical and social problem in the developing world and in the so-called hotspots, where it still causes around 500.000 deaths each year, not too different from the pre-antibiotic era. The role of genetic factors in RF susceptibility is discussed. Familiar aggregation, similarity of disease patterns between siblings, identical twin, and HLA correlation studies are evidence for a genetic influence on RF susceptibility. The suspect-involved genes fall mainly into those capable of immunologic mediation. Molecular mimicry explains the triggering of RF, but an intense and sustained inflammation is needed to cause sequels. Also, RF patients vary greatly in terms of symptoms. It is likely that a genetic background directing immune response towards a predominantly Th1 or Th2 pattern contributes to these features. The recent findings on rheumatic fever provide important insight on its physiopathology that helps understanding this prototype post-infectious autoimmune disease giving insights on other autoimmune conditions.

The immunobiology of Tourette's disorder, pediatric autoimmune neuropsychiatric disorders associated with Streptococcus, and related disorders: a way forward

Obsessive-compulsive disorder (OCD) and related conditions including Tourette's disorder (TD) are chronic, relapsing disorders of unknown etiology associated with marked impairment and disability. Associated immune dysfunction has been reported and debated in the literature since the late 80s. The immunologic culprit receiving the most interest has been Group A Streptococcus (GAS), which began to receive attention as a potential cause of neuropsychiatric symptoms, following the investigation of the symptoms reported in Sydenham's chorea (SC) and rheumatic fever, such as motor tics, vocal tics, and both obsessive-compulsive and attention deficit/hyperactivity symptoms. Young children have been described as having a sudden onset of these neuropsychiatric symptoms temporally associated with GAS, but without supporting evidence of rheumatic fever. This presentation of OCD and tics has been termed pediatric autoimmune neuropsychiatric disorders associated with Streptococcus (PANDAS). Of note, SC, OCD, and TD often begin in early childhood and share common anatomic areas--the basal ganglia of the brain and the related cortical and thalamic sites--adding support to the possibility that these disorders might share a common immunologic and/or genetic vulnerability. Relevant manuscripts were identified through searches of the PsycINFO and MedLine databases using the following keywords: OCD, immune, PANDAS, Sydenham chorea, Tourette's disorder Group A Streptococcus. Articles were also identified through reference lists from research articles and other materials on childhood OCD, PANDAS, and TD between 1966 and December 2010. Considering the overlap of clinical and neuroanatomic findings among these disorders, this review explores evidence regarding the immunobiology as well as the relevant clinical and therapeutic aspects of TD, OCD, and PANDAS.

Interleukin-1 receptor antagonist gene (IL1RN) polymorphism possibly associated to severity of rheumatic carditis in a Brazilian cohort

AIMS

To evaluate the IL1RN polymorphism as a possible marker for Rheumatic Fever (RF) susceptibility or disease severity.

METHODS

The genotypes of 84 RF patients (Jones criteria) and 84 normal race-matched controls were determined through the analysis of the number of 86-bp tandem repeats in the second intron of IL1RN. The DNA was extracted from peripheral-blood leukocytes and amplified with specific primers. Clinical manifestations of RF were obtained through a standardized questionnaire and an extensive chart review. Carditis was defined as new onset cardiac murmur that was perceived by a trained physician with corresponding valvae regurgitation or stenosis on echocardiogram. Carditis was classified as severe in the presence of congestive heart failure or upon the indication for cardiac surgery. The statistical association among the genotypes, RF and its clinical variations was determined.

RESULTS

The presence of allele 1 and the genotype A1/A1 were found less frequently among patients with severe carditis when compared to patients without this manifestation (OR=0.11, p=0.031; OR=0.092, p=0.017). Neither allele 1 nor allele 2 were associated with the presence of RF (p=0.188 and p=0.106), overall carditis (p=0.578 and p=0.767), polyarthritis (p=0.343 and p=0.313) and chorea (p=0.654 and p=0.633).

CONCLUSION

In the Brazilian population, the polymorphism of the IL-1ra gene is a relevant factor for rheumatic heart disease severity.

Adrenomedullin and total nitrite levels in children with acute rheumatic fever

OBJECTIVE

To investigate the levels of adrenomedullin (AM) and total nitrite, a stable product of nitric oxide (NO), in children with acute rheumatic fever (ARF).

DESIGN AND METHODS

Eleven children with ARF were investigated in comparison with 14 healthy controls. Adrenomedullin was detected by HPLC, while total nitrite was quantitated by the Griess reaction.

RESULTS

Plasma urinary AM and total nitrite levels were significantly higher in children with ARF, irrespective of whether they were in the acute or convalescent phase of disease. Plasma AM (pmol/mL) levels were 49.19 +/- 3.23 in the acute phase, 44.52 +/- 4.26 in the convalescent phase, 35.49 +/- 3.43 in controls, and urinary AM excretion (pmol/mg creatinine) was 43.45 +/- 18.40 in the acute phase, 32.38 +/- 15.37 in the convalescent phase, and 24.84 +/- 11.38 in controls. Plasma total nitrite levels (mumol/L) were 75.37 +/- 13.13 in the acute phase, 59.81 +/- 12.78 in the convalescent phase, and 41.09 +/- 10.27 in controls. Urinary total nitrite excretion (mumol/mg creatinine) was 3.82 +/- 1.56 in the acute phase, 2.15 +/- 0.58 in the convalescent phase, and 1.33 +/- 0.61 in controls. The differences were statistically significant for all (P < 0.05).

CONCLUSION

This study considered that AM and NO may have a role in the immunoinflammatory process of ARF.

Myocardial tissue damage in rabbits injected with group A streptococci, types M1 and M22. Role of bacterial immunoglobulin G-binding surface proteins

Acute rheumatic fever (ARF) and acute poststreptococcal glomerulonephritis (APSGN), two important sequelae of streptococcal throat or skin infections, according to current concepts may be elicited by autoimmune mechanisms due to molecular mimicry between group A streptococci (GAS) and human tissue. In the case of APSGN, however, our experimental data have indicated that GAS immunoglobulin-binding surface proteins (IgG BPs) might be of pathogenic significance by triggering anti-IgG production and immune complex formation leading to renal damage. Thus, rabbits injected with IgG-binding, as opposed to non-binding, GAS strains were found to develop renal deposition of IgG and complement factor C3 and inflammatory and degenerative glomerular changes resembling the picture seen in APSGN. In the present study, cardiac tissue material from rabbits injected with GAS was investigated. After 8 or more weeks of intravenous (i.v.) injections, minimal changes were seen in those animals receiving an IgG non-binding GAS strain, type T27, whereas those animals receiving either of two IgG-binding GAS strains, types M1 or M22, developed strong inflammatory and degenerative myocardial changes accompanied by deposition of IgG and C3. Furthermore, on injecting rabbits with defined mutants of a type M22 strain, the development of myocardial tissue damage proved to be dependent on the presence of streptococcal IgG-binding activity. Our results demonstrate that myocardial tissue changes may be induced in the rabbit by i.v. injection of whole heat-killed GAS of at least two M serotypes. Conceivably, induction of immune complexes by bacterial IgG BPs may lead to myocardial deposition of IgG, in turn triggering a series of events, involving the complement system and proinflammatory cytokines, with resulting tissue damage. Though many virulence factors may be involved in the development of ARF and APSGN, and a given GAS strain will never cause both, our results may suggest a new pathogenetic mechanism common to these two major non-suppurative complications.

Nitric oxide metabolities in acute rheumatic fever

Acute rheumatic fever (ARF), is a systemic inflammatory disease etiologically related to infection with group A beta hemolytic streptococcus, characterized by a broad spectrum of disorders in cellular immunity. To estimate the activity of the immunopathological process in patients with ARF, plasma nitric oxide metabolities (NOx) concentrations, IL-1alpha and IL-2 levels were investigated in 22 patients with ARF at the time on admission, and after 3 months, in children with chronic rheumatic heart disease (CRHD). Plasma NOx concentrations, IL-1alpha and IL/2 levels in patients with ARF on admission were significantly higher than in the same patients 3 months later, and higher than in CRHD, or controls. Increased plasma NO may be a useful index for the quantitative assessment of the activity during immunological challenge. This information may be useful for the prognosis and monitoring of ARF.

Selective depletion of Vbeta2+CD8+ T cells in peripheral blood from rheumatic heart disease patients

Acute rheumatic fever (ARF) and its chronic valvular sequelae are the delayed consequence of a pharyngeal infection with group A Streptococcus (GAS). Several GAS proteins have been shown to be superantigens, raising the possibility that the expansion or deletion of T cells expressing specific Vbeta regions might play a role in the pathogenesis of ARF or chronic rheumatic heart disease (RHD). We therefore analyzed by four-color flow cytometry, the Vbeta repertoire on CD3, CD4 and CD8 T cells from four ARF patients, 10 RHD patients and also nine healthy controls. A selective depletion of Vbeta2+ T cells was found only in the CD8 subset of chronic RHD patients. This is of interest since a number of GAS superantigens exert their effects on Vbeta2+ cells and because only CD8+ T cells from ARF and RHD patients undergo anergy in response to GAS superantigens. Our results suggests that an ongoing immune process is present in RHD patients and that CD8+ T cells may have an important immunoregulatory role in the pathogenesis of the disease.

Rheumatic disorders associated with streptococcal infections

The proteins in the cell wall of Streptococcus have many functions, with some proteins being regarded as a marker of their rheumatological potential. High levels of antibodies directed against some proteins are seen in patients with acute rheumatic fever. The theory of molecular mimicry forms the basis of the relationship between the bacteria and the disease acute rheumatic fever. A distinct entity which does not fulfil Jones' criteria, and which is known as post-streptococcal reactive arthritis following infection with beta-haemolytic streptococci, is being encountered more frequently. A pyogenic form of arthritis due to Streptococcus is one of the most common and serious joint infections and requires prompt recognition and treatment.

Immunogenic and Genetic Factors in Rheumatic Fever

Although rheumatic fever has virtually disappeared in many developed countries, it remains the number one acquired heart disease among children in developing countries. Many hypotheses advanced to explain the pathogenic mechanisms of this disease include the concept of an abnormal humoral and cellular response within the host to streptococcal antigens cross-reacting with mammalian tissues. This report examines the most recent evidence supporting this concept. It emphasizes the importance of the cellular arm of the immune response in cardiac damage, as wall as possible genetic disposition to the disease.

Pathogenesis of group A streptococcal infections

Group A streptococci are model extracellular gram-positive pathogens responsible for pharyngitis, impetigo, rheumatic fever, and acute glomerulonephritis. A resurgence of invasive streptococcal diseases and rheumatic fever has appeared in outbreaks over the past 10 years, with a predominant M1 serotype as well as others identified with the outbreaks. emm (M protein) gene sequencing has changed serotyping, and new virulence genes and new virulence regulatory networks have been defined. The emm gene superfamily has expanded to include antiphagocytic molecules and immunoglobulin-binding proteins with common structural features. At least nine superantigens have been characterized, all of which may contribute to toxic streptococcal syndrome. An emerging theme is the dichotomy between skin and throat strains in their epidemiology and genetic makeup. Eleven adhesins have been reported, and surface plasmin-binding proteins have been defined. The strong resistance of the group A streptococcus to phagocytosis is related to factor H and fibrinogen binding by M protein and to disarming complement component C5a by the C5a peptidase. Molecular mimicry appears to play a role in autoimmune mechanisms involved in rheumatic fever, while nephritis strain-associated proteins may lead to immune-mediated acute glomerulonephritis. Vaccine strategies have focused on recombinant M protein and C5a peptidase vaccines, and mucosal vaccine delivery systems are under investigation.

The arthritogenic properties of microbial antigens. Their implications in disease states

The sharing of antigenic determinants between host and microbe is a common event and new microbial-tissue cross-reactions are being recognized each year. Almost every human organ has been implicated as a possible target. The purpose of this article is to examine the arthritogenic properties of these microbial antigens and to explore the mechanisms by which they induce pathologic damage and disease.

Rheumatic fever. The relationships between host, microbe, and genetics

Acute rheumatic fever is a delayed, nonsuppurative sequela of a pharyngeal infection with the group A streptococcus. The onset of the disease is usually characterized by an acute febrile illness; however, there may be chronic involvement of the heart and/or central nervous system. The article explores the relationship between the initial infection and host-microbial interactions that may be operative in disease pathogenesis.

Molecular analysis of human cardiac myosin-cross-reactive B- and T-cell epitopes of the group A streptococcal M5 protein

The group A streptococcal M protein is an important virulence determinant eliciting protective and autoimmune responses against the streptococcus and cardiac myosin, respectively. In this report, the major human cardiac myosin-cross-reactive T-cell epitopes of M5 protein are identified and localized to myosin-like repeats within the M5 molecule. BALB/c mice were immunized with human cardiac myosin, and the dominant myosin-cross-reactive T-cell epitopes of M5 protein were identified with a panel of 23 overlapping peptides spanning the A, B, and C repeat regions of M5 protein. Human cardiac myosin-cross-reactive T-cell epitopes of M5 protein were localized to several sequences in the M5 peptides NT4 (GLKTENEGLKTENEGLKTE), NT5 (KKEHEAENDKLKQQRDTL), B1B2 (VKDKIAKEQENKETIGTL), B2 (TIGTLKKILDETVKDKIA), B3A (IGTLKKILDETVKDKLAK), and C3 (KGLRRDLDASREAKKQ). The NT4 repeated sequence LKTEN was highly homologous with a site conserved in cardiac myosins, the B repeat region peptides were 47% homologous to human cardiac myosin amino acid sequence, and the C3 sequence RRDL was identical to a highly conserved site in skeletal and cardiac myosins. Immunization of BALB/c mice with each of the overlapping M5 peptides revealed myosin-cross-reactive B-cell epitopes throughout the A and C repeat regions and one major epitope in the B repeat region containing the previously reported Gln-Lys-Ser-Lys-Gln (QKSKQ) epitope. The data suggest that the M5 peptides elicited higher antibody titers to cardiac myosin than to skeletal myosin and that several sites in the A and B repeat regions of M5 protein induced myocardial inflammatory infiltrates.

Preferential recognition of human myocardial antigens by T lymphocytes from rheumatic heart disease patients

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are autoimmune sequelae of upper respiratory infections with group A streptococci (GAS). To gain a better understanding of the pathogenesis of these diseases, we examined the in vitro proliferative responses of peripheral blood mononuclear cells (PBMC) from RHD patients to human myocardial proteins in a T-cell Western assay. A number of myocardial proteins fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were recognized by PBMC from both patients and controls. However, PBMC from a significant percentage of RHD patients (40%) responded to a discrete band of myocardial proteins migrating with an apparent molecular mass of 50 to 54 kDa while none of the control subject PBMC responded to this protein band (P < or = 0.0001). To further investigate the link between infections with GAS and autoimmune carditis, we studied the proliferative responses of PBMC from patients and controls to myocardial proteins before and after in vitro stimulation of the cells with opsonized GAS isolated from ARF patients. Priming of PBMC with rheumatogenic GAS caused the percentage of RHD patients responding to the 50- to 54-kDa myocardial proteins to increase from 43 to 90% (P < or = 0.0284). By contrast, PBMC from control subjects failed to recognize the 50- to 54-kDa myocardial proteins even after stimulation with the opsonized streptococci (P < or = 0.0001). The assay sensitivity was increased from 40 to 90% after priming of a patient's cells with opsonized GAS, but the positive predictive value was 100% in both unprimed and primed cultures. Antibodies generated to partially purified 50- to 54-kDa myocardial proteins did not cross-react with either streptococcal homogenates, purified M protein, myosin, laminin, or vimentin, suggesting a lack of cross-reactivity at the humoral level. This study suggests that the 50- to 54-kDa myocardial proteins contain a putative antigen that is preferentially recognized by T cells from RHD patients and demonstrates that exposure to streptococcal antigens enhances the ability of patients to recognize these proteins.

Expression of antigens associated with the individual stages of the inflammatory response in child and adult as a possible distinctive method for recurrent and chronic tonsillitis

Monoclonal antibodies (MoAbs) specific for the antigens associated with each stage of an inflammatory response were assayed with tonsillar mononuclear cells (TMNG). MoAbs BMA 27 E 10 and BMA 4 D 10 were used as markers for the early stages, BMA RM 3/1 for the intermediate stage, BMA 25 F 9 for the late stage, and BMA G 16/1 for the chronic stage. TMNC were obtained from patients operated for (1) recurrent tonsillitis with hypertrophy caused by common flora (children); (2) an indication for surgery for chronic tonsillitis in adults; (3) patients who were 'warm' tonsillectomized for a second peri-tonsillar phlegmon. Our results are presented and discussed in the light of their possible clinical significance. Our findings indicate that clinical chronic tonsillitis in the adult really is such. In the adults studied there was a high expression of antigens which is associated with the chronic stages, while the low expression of antigens is associated with the intermediate stage and an even lower antigen expression indicates the acute stage. In children what is considered to be chronic tonsillitis may perhaps be more correctly regarded as an expression of recurrent inflammation.

Antigenic specificity of lymphocytes isolated from valvular specimens of rheumatic fever patients

T cell lines were established from both valvular specimens and peripheral blood lymphocytes from seven patients with well documented rheumatic heart disease. These cell lines were stimulated with either PHA or streptococcal antigens. Proliferation assays revealed that both valvular and peripheral blood T cell lines reacted to cell wall (CW) and cell membrane (CM) antigens obtained from rheumatic fever associated group A streptococci and not to nephritogenic strains. None of the cell lines reacted to M protein, myosin or other mammalian cytoskeletal proteins. The unique reactivity of rheumatic fever T cell lines only to cellular structures obtained from rheumatogenic strains suggests that these lines react to epitopes specific for antigens obtained from these strains.

Plasma interleukin-7 (IL-7) and IL-8 concentrations in acute rheumatic fever and chronic rheumatic heart disease

Interleukin-7 (IL-7) and IL-8 productions in 25 children with acute rheumatic fever (ARF) and in 15 children with chronic rheumatic heart disease (CRHD) and in 15 children with streptococcal pharyngitis (SP), were investigated in order to determine whether they have a role in the pathogenesis of rheumatic fever. Significantly higher IL-8 levels were found in ARF patients in the clinically active period. IL-7 concentrations remained unchanged during different stages of rheumatic fever. The decrease of elevated IL-8 concentrations within 3 months and normal IL-8 concentrations in patients with CRHD and SP indicate an excessive production of IL-8, probably by cellular infiltrates in the joint throughout the active period of rheumatic disease.

Pediatric rheumatic diseases

The rheumatic diseases of childhood are a relatively common and extraordinarily diverse group of illnesses; nevertheless, they are at least distantly related by similarities of immunodysregulation. These pathophysiologic relationships are reflected in affected children in similarities of historical, physical, and laboratory data as well as therapeutic intervention.

Beta haemolytic streptococci and reactive arthritis in adults

There is an increasing occurrence of reactive group A beta haemolytic streptococci (BHS) phenomena. This review makes a case for considering BHS in the differential diagnosis of adult reactive arthritis. This is based on (a) published reports over the past 45 years describing first attacks of rheumatic fever in adults; (b) the longstanding observation that polyarthritis is the most commonly expressed Jones major criterion in adults; (c) the broad spectrum of clinical expression of disease following streptococcal infection, with the re-emergence of the term 'poststreptococcal reactive arthritis'. The arthritis in adult rheumatic fever is characterised by sequential involvement of large weightbearing joints. Recurrent, severe, prolonged arthritis has been a prominent feature of adult poststreptococcal reactive arthritis. Carditis has been reported in 33% of adult patients with rheumatic fever. Consequently long term antibiotic prophylaxis for adults with reactive BHS phenomena should be strongly considered, and guidelines are suggested for this in individual patients. Further areas for research are discussed, particularly the interrelations between bacteria and host in disease expression, and the possibility that BHS might play a part in chronic arthritides and vasculitides.

Enhancement of IL-1, IL-2 production and IL-2 receptor generation in patients with acute rheumatic fever and active rheumatic heart disease; a prospective study

In a prospective study, patients with quiescent rheumatic heart disease (CRHD), streptococcal pharyngitis (SP) and healthy normal subjects produced comparable amounts of IL-1 and IL-2, but acute rheumatic fever (ARF) patients produced significantly elevated amounts of IL-1 and IL-2 at all intervals up to 48 weeks. In active rheumatic heart disease (ARHD), IL-1 activity returned to within normal range at 48 weeks, but IL-2 activity remained persistently elevated compared with CRHD, SP and healthy age- and sex-matched volunteers. CD4+ T lymphocytes were significantly increased in the peripheral blood of ARF and ARHD patients. The amount of IL-2 produced by ARF and ARHD patients correlated with the percentage of helper T lymphocytes (CD4+ cells) but not with the percentage of suppressor/cytotoxic T lymphocytes (CD8+ cells). Moreover, pre- and post-phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cell (PBMC) cultures from ARF and ARHD patients contained higher proportions of IL-2R+ (CD25+) cells than those from patients with SP, CRHD and normal individuals, which persisted up to 48 weeks. The percentage of CD25+ cells in both types of PBMC cultures directly correlated with the percentage of CD4+ cells and not with CD8+ cells in active rheumatic patients only. These findings indicate that the immune response in ARF and ARHD patients is skewed to produce activated helper T cells that release IL-2 which drives the accumulation of more T helper cells. The result is an undamped helper T cell response in the peripheral blood of these patients.

Immunological investigations on tonsillar and peripheral blood lymphocytes after adeno-tonsillectomy. Possible suggestions for phenotypical and functional differences

The phenotypical and functional aspects of tonsillar (TMNC) and peripheral blood mononuclear cells (PBMNC) obtained from 40 patients who had undergone adeno-tonsillectomy for different tonsillar diseases were investigated. TMNC and PBMC were separately tested at the time of surgery; then a further investigation on the peripheral blood lymphocytes was performed three months after surgery. The most interesting findings are presented and discussed with particular attention to their clinical implications.

Identification of mononuclear cells and T cell subsets in rheumatic valvulitis

The composition of the mononuclear cellular filtrates was investigated in 13 valve specimens from nine patients with rheumatic carditis, some of whom had clinical and laboratory evidence of acute disease at the time of surgery. In acute valvulitis (AV) as well as in chronic active valvulitis (CAV), the cellular infiltrates were primarily composed of T cells and macrophages. In AV the majority of these T cells were of the helper phenotype (Leu 3a). The T cells subsets were more heterogeneous in CAV. In five valves, the helper T cells exceeded the number of suppressor T cells, whereas in three others, helper and cytotoxic/suppressor T cells were present in equal numbers. The HLA-DR antigen was expressed by the majority of the mononuclear cells and by the vascular endothelium. These findings indicate that the valvular injury may at least in part be mediated by delayed-type hypersensitivity mechanisms. Those cells comprising the Aschoff body were primarily positive for the HLA-DR and a novel monoclonal antibody called D8/17 which identifies an antigen known to be present on the B cells of rheumatic fever patients.