Sickening or Healing the Heart? The Association of Ficolin-1 and Rheumatic Fever.

Rheumatic fever (RF) and its subsequent progression to rheumatic heart disease (RHD) are chronic inflammatory disorders prevalent in children and adolescents in underdeveloped countries, and a contributing factor for high morbidity and mortality rates worldwide. Their primary cause is oropharynx infection by Streptococcus pyogenes, whose acetylated residues are recognized by ficolin-1. This is the only membrane-bound, as well as soluble activator molecule of the complement lectin pathway (LP). Although LP genetic polymorphisms are associated with RF, FCN1 gene's role remains unknown. To understand this role, we haplotyped five FCN1 promoter polymorphisms by sequence-specific amplification in 193 patients (138 with RHD and 55, RF only) and 193 controls, measuring ficolin-1 serum concentrations in 78 patients and 86 controls, using enzyme-linked immunosorbent assay (ELISA). Patients presented lower ficolin-1 serum levels (p < 0.0001), but did not differ according to cardiac commitment. Control's genotype distribution was in the Hardy-Weinberg equilibrium. Four alleles (rs2989727: c.-1981A, rs10120023: c.-542A, rs10117466: c.-144A, and rs10858293: c.33T), all associated with increased FCN1 gene expression in whole blood or adipose subcutaneous tissue (p = 0.000001), were also associated with increased protection against the disease. They occur within the *3C2 haplotype, associated with an increased protection against RF (OR = 0.41, p < 0.0001) and with higher ficolin-1 levels in patient serum (p = 0.03). In addition, major alleles of these same polymorphisms comprehend the most primitive *1 haplotype, associated with increased susceptibility to RF (OR = 1.76, p < 0.0001). Nevertheless, instead of having a clear-cut protective role, the minor c.-1981A and c.-144A alleles were also associated with additive susceptibility to valvar stenosis and mitral insufficiency (OR = 3.75, p = 0.009 and OR = 3.37, p = 0.027, respectively). All associations were independent of age, sex or ethnicity. Thus, minor FCN1 promoter variants may play a protective role against RF, by encouraging bacteria elimination as well as increasing gene expression and protein levels. On the other hand, they may also predispose the patients to RHD symptoms, by probably contributing to chronic inflammation and tissue injury, thus emphasizing the dual importance of ficolin-1 in both conditions.

What is the true frequency of carditis in acute rheumatic fever? A prospective clinical and Doppler blind study of 56 children with up to 60 months of follow-up evaluation.

BACKGROUND: This study aimed to evaluate prospectively clinical and echocardiographic findings of patients who had rheumatic fever with and without clinical features of cardiac involvement. METHODS: For this study, 56 consecutive patients (mean age, 11.4 years) with acute rheumatic fever diagnosed according to the 1992 modified Jones criteria were evaluated at diagnosis, after 3 and 6 months, then at 2 and 5 years. All assessments were performed blindly and included physical and cardiac examination, electrocardiogram, chest X-ray, and two-dimensional color-flow Doppler echocardiography. RESULTS: Initial clinical carditis was observed for 27 patients (48.2%), all of whom had positive echocardiographic abnormalities. Echocardiographic abnormalities were observed in 11 patients who had arthritis or chorea presentation without initial clinical carditis. Persistence of the abnormalities was observed at a late follow-up evaluation in 72.7% of the cases. Sydenham's chorea was present in 8 patients with clinical carditis and in 10 without this disorder, 8 of whom had echocardiographic abnormalities. CONCLUSION: Patients who had acute rheumatic fever without clinical signs of carditis showed acute and late follow-up echocardiographic abnormalities suggestive of cardiac involvement. Clinicians should be attentive for the presence of cardiac involvement among patients with chorea.

[Presence of bacterial DNA in valvular tissue of patients with chronic rheumatic heart disease]. / Presencia de ADN bacteriano en el tejido valvular de pacientes con cardiopatía reumática crónica.

BACKGROUND: Rheumatic heart disease (RHD) is a delayed consequence of a pharyngeal infection with Group A streptococcus (GAS), usually ascribed to a cross-reactive immune response to the host cardiac tissues. Acute rheumatic fever (ARF) and its ensuing valvular sequelae are thus considered the prototype of a post-infectious autoimmune disease, with no direct evidence of residual streptococcal antigen in diseased valvular tissues. However, recent studies concerning the antigenic specificity and clonality of intralesional lymphocytes have revealed oligoclonal expansions characteristic of an antigen specific response, that might be related to GAS. AIM: To search for bacterial DNA in valvular tissue from RHD patients and controls. MATERIAL AND METHODS: We extracted DNA from surgically excised valve specimens from 15 RHD patients and 6 non RHD controls and tested for the presence of bacterial DNA by Polymerase Chain Reaction (PCR) with primers for 16S rRNA. RESULTS: Eighty percent (12/15) of valve specimens from RHD patients were positive for bacterial DNA, as opposed to none of the valves (n =6) from non RHD controls. CONCLUSIONS: These results suggest that GAS might persist in valvular tissue in patients with ARF and contribute to the inflammatory scarring lesion that leads to cardiovascular sequelae.

Presencia de ADN bacteriano en el tejido valvular de pacientes con cardiopatía reumática crónica / Presence of bacterial DNA in valvular tissue of patients with rheumatic heart disease

Background: Rheumatic heart disease (RHD) is a delayed consequence of a pharyngeal infection with Group A streptococcus (GAS), usually ascribed to a cross-reactive immune response to the host cardiac tissues. Acute rheumatic fever (ARF) and its ensuing valvular sequelae are thus considered the prototype of a post-infectious autoimmune disease, with no direct evidence of residual streptococcal antigen in diseased valvular tissues. However, recent studies concerning the antigenic specificity and clonality of intralesional lymphocytes have revealed oligoclonal expansions characteristic of an antigen specific response, that might be related to GAS. Aim: To search for bacterial DNA in valvular tissue from RHD patients and controls. Material and methods: We extracted DNA from surgically excised valve specimens from 15 RHD patients and 6 non RHD controls and tested for the presence of bacterial DNA by Polymerase Chain Reaction (PCR) with primers for 16S rRNA. Results: Eighty percent (12/15) of valve specimens from RHD patients were positive for bacterial DNA, as opposed to none of the valves (n =6) from non RHD controls. Conclusions: These results suggest that GAS might persist in valvular tissue in patients with ARF and contribute to the inflammatory scarring lesion that leads to cardiovascular sequelae.

Molecular pathogenesis of rheumatic fever and rheumatic heart disease.

Molecular mimicry between streptococcal and human proteins has been proposed as the triggering factor leading to autoimmunity in rheumatic fever (RF) and rheumatic heart disease (RHD). This article summarises studies on genetic susceptibility markers involved in the development of RF/RHD. It also focuses on the molecular mimicry in RHD mediated by the responses of B and T cells of peripheral blood, and T cells infiltrating heart lesions, against streptococcal antigens and human tissue proteins. The molecular basis of T-cell recognition is assessed through the definition of heart-crossreactive antigens. The production of cytokines from peripheral and heart-infiltrating mononuclear cells suggests that T helper 1 (Th1)-type cytokines are the mediators of RHD heart lesions. An insufficiency of interleukin 4 (IL-4)-producing cells in the valvular tissue might contribute to the maintenance and progression of valve lesions.

Salivary Streptococcus mutans and Lactobacillus sp levels in cardiac children.

This study assesses salivary conditions of 20 children with cardiac disease comparing with a control group of 15 healthy children. The results showed that there was no difference between the groups on salivary flow, buffer capacity and the level of Streptococcus mutans (Sm). The test group i.e., children with cardiac disease, showed a lower level of Lactobacillus sp. The association between the usage of antibiotics and the risk of developing caries, measuring the level of Streptococcus mutans and Lactobacillus sp., showed that children taking antibiotics frequently had a significant lower level of Lactobacillus sp (p<0.05) than healthy children. This association was not found on relation to the levels of Streptococcus mutans.