Invasive group A streptococcal infection with pancarditis caused by a new emm-type 12 allele of Streptococcus pyogenes

Throughout the 1980s, a progressive increase in the incidence of Streptococcus pyogenes-related invasive infections has occurred. It has been suggested that a host-related immunogenetic background, as well as bacterial virulence factors may play an important role in the outcome of streptococcal infections. Here, we present the first case of pancarditis in the literature caused by direct bacterial invasion due to a new emm-type 12 allele of S. pyogenes in an immunocompetent patient. The pathogenesis of this invasive infection, as well as predictors of poor prognosis are discussed.

Cardiac Histological Substrate in Patients With Clinical Phenotype of Brugada Syndrome

Background— The role of structural heart disease and sodium channel dysfunction in the induction of electrical instability in Brugada syndrome is still debated.

Methods and Results— We studied 18 consecutive patients (15 males, 3 females; mean age 42.0±12.4 years) with clinical phenotype of Brugada syndrome and normal cardiac structure and function on noninvasive examinations. Clinical presentation was ventricular fibrillation in 7 patients, sustained polymorphic ventricular tachycardia in 7, and syncope in 4. All patients underwent cardiac catheterization, coronary and ventricular angiography, biventricular endomyocardial biopsy, and DNA screening of the SCN5A gene. Biopsy samples were processed for histology, electron microscopy, and molecular screening for viral genomes. Microaneurysms were detected in the right ventricle in 7 patients and also in the left ventricle in 4 of them. Histology showed a prevalent or localized right ventricular myocarditis in 14 patients, with detectable viral genomes in 4; right ventricular cardiomyopathy in 1 patient; and cardiomyopathic changes in 3. Genetic studies identified 4 carriers of SCN5A gene mutations that cause in vitro abnormal function of mutant proteins. In these patients, myocyte cytoplasm degeneration was present at histology, whereas terminal dUTP nick end-labeling assay showed a significant increase of apoptotic myocytes in right and left ventricle versus normal controls ( P =0.014 and P =0.013, respectively).

Conclusions— Despite an apparently normal heart at noninvasive evaluation, endomyocardial biopsy detected structural alterations in all 18 patients with Brugada syndrome. Mutations in the SCN5A gene, identified in 4 of the 18 patients, may have induced concealed structural abnormalities of myocardiocytes that accounted for paroxysmal arrhythmic manifestations.

Cardiac apoptosis in severe relapsing fever borreliosis

Previous studies revealed that the heart suffers significant injury during experimental Lyme and relapsing fever borreliosis when the immune response is impaired (D. Cadavid, Y. Bai, E. Hodzic, K. Narayan, S. W. Barthold, and A. R. Pachner, Lab. Investig. 84:1439-1450, 2004; D. Cadavid, T. O'Neill, H. Schaefer, and A. R. Pachner, Lab. Investig. 80:1043-1054, 2000; and D. Cadavid, D. D. Thomas, R. Crawley, and A. G. Barbour, J. Exp. Med. 179:631-642, 1994). To investigate cardiac injury in borrelia carditis, we used antibody-deficient mice persistently infected with isogenic serotypes of the relapsing fever agent Borrelia turicatae. We studied infection in hearts 1 to 2 months after inoculation by TaqMan reverse transcription-PCR and immunohistochemistry (IHC) and inflammation by hematoxylin and eosin and trichrome staining, IHC, and in situ hybridization (ISH). We studied apoptosis by terminal transferase-mediated DNA nick end labeling assay and measured expression of apoptotic molecules by RNase protection assay, immunofluorescence, and immunoblot. All antibody-deficient mice, but none of the immunocompetent controls, developed persistent infection of the heart. Antibody-deficient mice infected with serotype 2 had more severe cardiac infection and injury than serotype 1-infected mice. The injury was more severe around the base of the heart and pericardium, corresponding to sites of marked infiltration by activated macrophages and upregulation of interleukin-6 (IL-6). Infected hearts showed evidence of apoptosis of macrophages and cardiomyocytes as well as significant upregulation of caspases, most notably caspase-1. We conclude that persistent infection with relapsing fever borrelias causes significant loss of cardiomyocytes associated with prominent infiltration by activated macrophages, upregulation of IL-6, induction of caspase-1, and apoptosis.

Distinct bacterial dissemination and disease outcome in mice subcutaneously infected withBorrelia burgdorferiin the midline of the back and the footpad

Subcutaneous inoculation of mice with Borrelia burgdorferi, the causative agent of Lyme disease, results in established infection and the development of acute arthritis and carditis, hallmarks of human disease. Because conflicting results may originate from the site of subcutaneous inoculation, we addressed the dissemination capacity of spirochetes injected in the shoulder region versus the footpad. Spirochetes inoculated in the footpad disseminated to a lesser extent to distant organs, such as the ear and the heart. This resulted in distinct degrees of joint and cardiac inflammation at the peak of the disease. The differences eventually leveled out. These results suggest that caution must be exercised in the interpretation of results obtained with routes of inoculation that do not closely represent the natural site of infection.

[Extrapulmonary infections due to Mycoplasma pneumoniae]

Pneumonia is the main site of infection with Mycoplasma pneumoniae in paediatric age. Nevertheless it can also give rise to other manifestations, with or without respiratory involvement. In the present review are described some unusual clinical features of M. pneumoniae in children. Encephalitis and meningoencephalitis is the most frequent neurological manifestation, but cases of meningitis, myelitis, and polyradiculitis, have been reported. Cardiac involvement is potentially severe, including pericarditis and myocarditis. Cold agglutinin haemolytic anaemia is the most frequent haematologic manifestation. Skin, renal, gastro-intestinal, osteoarticular, and other manifestations have also been reported in the literature. The pathogeny of these extrapulmonary infections is not fully elucidated and the treatment remains partly controversial. Extrapulmonary complications can occur as a result of direct invasion and/or autoimmune response.

Adult-Onset Acute Rheumatic Fever

BACKGROUND

By the late 1980s, acute rheumatic fever (ARF) had become a rare disease in Taiwan. The low prevalence rate in this area is attributed to a better economic status, which has led to improved public health and adequate medical services.

OBJECTIVES

The increasing number of patients with adult-onset ARF in the United States described in the literature prompted us to evaluate the cases diagnosed in our medical center.

METHODS

A retrospective chart review was performed for patients with arthritis from July 1988 to October 2004. To be included, patients had to meet revised Jones criteria.

RESULTS

Three adult patients with ARF have been diagnosed since June 2001, with no childhood ARF being diagnosed. All cases presented with migratory polyarthritis, whereas 1 had erythema marginatum and transient carditis. These patients responded well to treatment with antibiotics and nonsteroidal antiinflammatory drugs.

CONCLUSIONS

Clinicians must provide careful assessment and treatment to patients presenting with acute pharyngitis. A possible resurgence of ARF can be eradicated by primary prevention of streptococcal pharyngitis.

Myocarditis, microbes and autoimmunity

Acute and chronic myocarditis can be caused by a number of infectious agents, including viruses, bacteria and protozoa. These diseases are refractory to treatment, and the development of rational therapies will require a detailed understanding of the mechanisms that underlie the pathological inflammatory responses. Here, we review three infectious myocarditides that, despite the dissimilarity of the microorganisms, share several common features: (i) the microbes replicate in the heart; but (ii) are difficult to isolate, in infectious form, during chronic disease; (iii) autoreactive antibodies and T cells specific for cardiac antigens have been identified in infected animals; and (iv) these autoreactive responses have been proposed as the main effectors of cell death, and myocardial damage. We critically evaluate the data, and we suggest that the findings can be reconciled without invoking autoimmunity as an effector mechanism. Alternative hypotheses to explain the tissue destruction are proposed.

[Acute myocarditis with Toxoplasma gondii. A case report in a newborn]

Acute myocarditis with Toxoplasma Gondii in immunocompetent patients is rare and the paediatric cases touch old children. These myocarditis lead sometimes cardiac insufficiency and sometimes mimic a myocardial infarction. The evolution is often favorable, even when there is no pest-destroying treatment. We report a case of myocarditis toxoplasma Gondii with which has occurred in a 11 month and half old infant, whose evolution was favorable with a symptomatic and pest-destroying treatment. The interest of this observation is related to the scarcity of acute myocarditis caused by toxplasmosis in infant without immunoinsufficiency.

Cardiac Aspergillosis in Patients With Acquired Immunodeficiency Syndrome: A Case Report and Review of the Literature

Cardiac aspergillosis is uncommon in patients with acquired immunodeficiency syndrome (AIDS) in the absence of open heart surgery. We report a unique case of a 62-year-old man with AIDS who developed Aspergillus pancarditis with Aspergillus vegetations on mitral valve without evidence of pulmonary aspergillosis. There was extensive embolization to the brain and multiple foci of Aspergillus infection in kidneys and adrenal glands. There are only 10 documented cases of cardiac aspergillosis in the literature (1966–2003) in severely immunocompromised AIDS patients with CD4 T-lymphocyte counts ranging from 10 to 121 cells/μL. The cardiac aspergillosis could result from invasive pulmonary aspergillosis, either by hematogenous dissemination or by direct invasion, and skin Aspergillus infection can be carried through the bloodstream to the right heart in intravenous drug abusers. Most of the reported cases of cardiac aspergillosis were diagnosed at autopsy. Mortality among AIDS patients with cardiac aspergillosis is 100%, despite appropriate therapy.

Elevated expression of PDGF-C in coxsackievirus B3-induced chronic myocarditis

AIMS

Coxsackievirus B3 (CVB3) is a frequent cause of human chronic myocarditis and subsequent fibrosis, leading to dilated cardiomyopathy. The molecular processes underlying the development of fibrosis are poorly understood. Enhanced levels of platelet-derived growth factors (PDGFs), especially PDGF-C, have recently been linked with the development of different forms of fibrosis. Therefore, the expression of PDGF was analysed in hearts of CVB3-infected major histocompatability complex class II knockout mice. The latter were recently established as mouse model mimicking the chronic inflammation and fibrosis characteristic for this disease.

METHODS AND RESULTS

Expression of PDGF was analysed by reverse transcription-polymerase chain reaction, in situ hybridization, and immunohistochemistry. Hearts of C57BL/6 mice served as controls because infection of these animals leads to acute cardiac inflammation, but the hearts heal without signs of chronic inflammation. In uninfected hearts, basal expression of PDGF, notably PDGF-C, was detectable throughout the heart. The chronic inflammatory process was associated with elevated and sustained expression of all tested PDGF isoforms. Immunostaining and in situ hybridization analysis localized enhanced PDGF levels to areas with highest virus load and inflammatory infiltrations, adjacent to fibrotic areas.

CONCLUSION

PDGF may participate in fibrosis development in CVB3-induced myocarditis. Therefore, PDGF signalling may be considered a target for therapeutic interference.

[Cardiac abnormalities of lyme borreliosis]

The article summarizes basic characteristics of Lyme borreliosis, its incidence, epidemiology, pathogenesis and clinical image. Particular attention is given to the review of papers aimed at the cardiac abnormalities--the Lyme carditis. Though they are not very frequent, due to the variability of their clinical course and due to various forms, which are difficult to diagnose, they can represent a specific problem. Major part of the article is given to the authors' own experience with the dilated cardiomyopathy of the Borrelia origin and namely to the perspective study of the patients after the skin form of the disease erythema migrans, who were treated "lege artis" in the early phase of the disease with antibiotics. Authors were interested how many of those patients would develop later the cardiac abnormalities.

Lyme borreliosis--waiting for Lyme carditis? A long-term prospective study

A long-term prospective study of patients with confirmed non-cardiac form of Lyme disease (n=221) over a mean follow-up period of 40.6 months is reported. The study revealed no case of Borrelia-related cardiac involvement developed after several years in patients who had received antibiotic therapy in the early period. Therefore, these patients do not need follow-up by a cardiologist.

Cardiac involvement in non-human primates infected with the Lyme disease spirochete Borrelia burgdorferi

To investigate cardiac involvement in the non-human primate (NHP) model of Lyme disease, we inoculated 39 adult Macaca mulatta with Borrelia burgdorferi sensu stricto strains N40 (BbN40) by needle (N=22, 14 immunocompetent (IC), seven permanently immunosuppressed (IS), and four transiently immunosuppressed (TISP)) or by tick-bite (N=4, all TISP) or strain 297 (Bb297) by needle (N=2 IS), or with B. garinii strains Pbi (N=4, 2 TISP and 2 IS), 793 (N=2, TISP) or Pli (N=2, TISP). Five uninfected NHPs were used as controls. Infection and inflammation was studied in the hearts and the aorta removed at necropsy 2-32 months after inoculation by (1) H&E and trichrome-staining; (2) immunohistochemistry and digital image analysis; (3) Western blot densitometry; and (4) TaqMan RT-PCR. All NHPs inoculated with BbN40 became infected and showed carditis at necropsy. The predominant cells were T cells, plasma cells, and macrophages. There was increased IgG and IgM in the heart independent of immunosuppression. The B-cell chemokine BLC was significantly increased in IS-NHPs. There was increased deposition of the complement membrane attack complex (MAC) in TISP and IS-NHPs. The spirochetal load was very high in all BbN40-inoculated IS-NHPs but minimal if any in IC or TISP NHPs. Double-immunostaining revealed that many spirochetes in the heart of BbN40-IS NHPs had MAC on their membranes. We conclude that carditis in NHPs infected with B. burgdorferi is frequent and can persist for years but is mild unless they are immunosupressed.

Treatment of Inflammatory Dilated Cardiomyopathy and (Peri)Myocarditis with Immunosuppression and i.v. Immunoglobulins

OBJECTIVES

Treatment objectives in inflammatory dilated cardiomyopathy (DCMi), myocarditis (M) and peri(myo)carditis are 1) the elimination of inflammatory cells from the myocardium and pericardium, 2) the elimination or (second best) mitigation of B-cell products such as antibodies and immuncomplexes directed against cardiac epitopes such as sarcolemmal, fibrillary and mitochondrial epitopes, and 3) the eradication of the causative viral or microbial agent, if present.

ANTIPHLOGISTIC TREATMENT

A "non-specific" anti-inflammatory treatment in peri(myo)carditis can be carried out with antiphlogistics (NSAIDs preferably colchicine 1-3 mg/d) independent from the presence of the infective agent. In larger virus and bacteria negative effusions we recommend intrapericardial instillation of cristalloid triamcinolon (Volon A) at a dose of 500 mg/m(2), which should be left in place to have a sustained effect over at least 4 weeks. This will effectively prevent recurrences particularly when colchicine is added over a period of at least 3-6 months. Taking into account the 2004 ESC task force recommendations on the management of pericardial diseases the treatment recommendation for NSAIDs and colchicine can be classified as level of evidence A, indication class I, for intrapericardial triamcinolon instillation as level of evidence B, indication class IIa.

IMMUNOSUPPRESSION

In (immuno)histologically validated autoreactive (virus negative) myocarditis and DCMi double-blind randomized trials are lacking to demonstrate the superiority of immunosuppression over conventional heart failure management. The only published randomized and double-blind immunosuppression treatment trial (American Myocarditis Treatment Trial) was underpowered and did not distinguish viral from non-viral disease. It showed neither benefit nor harm of a combination of cyclosporin and prednisone. A number of retrospective analyses of immunosuppression in myocarditis showed some benefit of surrogate parameters (ejection fraction, exercise tolerance) but improvement under conventional heart failure treatment cannot be ruled out completely as the main cause for amelioration. ESETCID (European Study on the Epidemiology and Treatment of Cardiac Inflammatory Disease) is a double-blind, randomized, placebo-controled three-armed trial with prednisolone and azathioprine for autoreactive (virus negative) DCMi, interferon alpha for enterovirus positive DCMi, high-dose immunoglobulin for cytomegalovirus and intermediate dose for adeno- and Parvo B19 DCMi. It has now randomized more than 120 patients to the different treatment arms. Its final result has still to be awaited.-Patients not willing to randomize in the trial were included in a registry follow-up, which shows improvement of hemodynamic parameters and elimination of the inflammation in the majority of patients. This is in concordance with several non-randomized trials. Since evidence is conflicting (level of evidence C, indication class IIb; if negative viral etiology is taken into consideration class IIa) treatment with immunosuppression cannot be generally recommended but should be further evaluated in doubleblind randomized clinical trials or at least in controlled trials and registries. This also applies to treatment with interferon for enteroviral or other viral infections in the heart.

IMMUNOADSORPTION

: The elimination of anticardiac antibodies, which have been associated with DCMi, is a currently discussed concept, which is supported by published registry data and a few very small controlled investigations but not by a randomized double-blind trial with clinical endpoints of relevance. In some studies immunoglobulins have been substituted, so that an additional immunomodulatory effect has to be taken into account. The current proof of concept can be ranked level of evidence C, indication class IIa only. An even more challenging and still more attractive hypothesis is that cardiac inflammation caused by specific circulating beta-adrenoceptor antibodies can be eradicated with the elimination of the beta-receptor antibody thus healing dilated cardiomyopathy. Application of this approach can be ranked level of evidence C, indication class IIb at present only. Therefore these two pathophysiologically attractive concepts have to await further validation by a double-blind, randomized clinical endpoint trial.

IMMUNOGLOBULIN TREATMENT

It has been shown that immunoglobulins have both an antiviral and an anti-inflammatory effect. They may suppress proinflammatory cytokines and reduce oxidative stress. HIGH-DOSE I.V.

IMMUNOGLOBULINS (IVIG)

In biopsy proven CMVmyocarditis a controlled trial demonstrated eradication of inflammation and of the virus (level of evidence B, indication class IIa), which is in accordance with registry data and case reports. In suspected myocarditis (not biopsy proven, no viral etiology established or excluded) conflicting data exist with respect to the improvement of surrogate markers such as the ejection fraction under high-dose immunoglobulins. More evidence can be weighted in favour of a positive treatment effect (level of evidence B, indication class IIb). Importantly there were no detrimental effects of the ivIG reported in these trials. One has to consider the high costs of this treatment, however. A trial taking into account the different etiologies (different viruses assessed separately vs. non-viral/autoreactive vs. placebo) is still lacking. MODERATE-DOSE I.V.

IMMUNOGLOBULINS

Registry data support a positive effect of 20 g i.v. pentaglobin (IgG and IgM) in adenovirus positive myocarditis for clinical improvement, eradication of both the inflammation and the virus. In Parvo B19 myocarditis our own registry data indicate that clinical improvement can be noted, but only inflammation is successfully eliminated, whereas Parvo B19 persistence remains a problem in the majority of patients. In Parvo B19 associated DCMi therefore dose finding studies and randomized trials are needed.

Severe influenza B myocarditis and myositis

OBJECTIVE

To report an influenza B infection with associated myocarditis and severe skeletal myositis.

DESIGN

Case report.

SETTING

Cardiac intensive care unit in a university-affiliated children's hospital.

PATIENT

A 4-yr-old girl.

RESULTS

The patient was successfully supported with extracorporeal membrane oxygenation for profound myocardial dysfunction and a combination of plasmapheresis and continuous venovenous hemodialysis for rhabdomyolysis and acute renal failure.

CONCLUSIONS

This case provides a reminder that patients presenting with viral illness or myoglobinuria accompanied by renal failure, with or without associated myocarditis, may be demonstrating symptoms of influenza B.

Lyme Carditis

Lyme disease is a tickborne illness that could cause, weeks to months later, complications involving the joints, central nervous system, and cardiovascular system. We report a case of cardiac manifestation with transitory higher degree atrioventricular block and dysfunction of the left ventricle. Complete resolution without signs of myocardial scar is demonstrated by cardiac magnetic resonance imaging.

Myeloid differentiation antigen 88 deficiency impairs pathogen clearance but does not alter inflammation in Borrelia burgdorferi-infected mice

The spirochete Borrelia burgdorferi causes acute inflammation in mice that resolves with the development of pathogen-specific adaptive immunity. B. burgdorferi lipoproteins activate innate immune cells via Toll-like receptor 2 (TLR2), but TLR2-deficient mice are not resistant to B. burgdorferi-induced disease, suggesting the involvement of other TLRs or non-TLR mechanisms in the induction of acute inflammation. For this study, we used mice that were deficient in the intracellular adapter molecule myeloid differentiation antigen 88 (MyD88), which is required for all TLR-induced inflammatory responses, to determine whether the interruption of this pathway would alter B. burgdorferi-induced disease. Infected MyD88(-/-) mice developed carditis and arthritis, similar to the disease in wild-type (WT) mice analyzed at its peak (days 14 and 28) and during regression (day 45). MyD88(-/-) macrophages produced tumor necrosis factor alpha only when spirochetes were opsonized, suggesting a role for B. burgdorferi-specific antibody in disease expression. MyD88(-/-) mice produced stronger pathogen-specific Th2-dependent immunoglobulin G1 (IgG1) responses than did WT mice, and their IgM titers remained significantly elevated through 90 days of infection. Despite specific antibodies, the pathogen burden was 250-fold higher in MyD88(-/-) mice than in WT mice 45 days after infection; by 90 days of infection, the pathogen burden had diminished substantially in MyD88(-/-) mice, but it was still elevated compared to that in WT mice. The elevated pathogen burden may be explained in part by the finding that MyD88(-/-) peritoneal macrophages could ingest spirochetes but degraded them more slowly than WT macrophages. Our results show that MyD88-dependent signaling pathways are not required for B. burgdorferi-induced inflammation but are necessary for the efficient control of the pathogen burden by phagocytes.

Induction of myocarditis in rabbits injected with group A streptococci

BACKGROUND & OBJECTIVES

We have earlier proposed that group A streptococcal (GAS) immunoglobulin binding surface proteins (IgGBPs) might trigger anti-IgG production and immune complex formation leading to glomerulonephritis. In the present study, cardiac tissue material from rabbits injected with heat-killed GAS was investigated.

METHODS

Rabbits were injected intravenously with 10(9) colony forming units of streptococci three times weekly for 8 wk. Cardiac tissue samples were obtained at different times and deposition of IgG, C3, TNF-alpha and IL-6 was studied.

RESULTS

After 8 or more weeks of intravenous (iv) injections, minimal changes were seen in animals receiving an IgG non-binding GAS strain, type T27, whereas in those animals receiving either of two IgG binding GAS strains, types M1 or M22, strong inflammatory and degenerative myocardial changes accompanied by deposition of IgG and C3 were noted. 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 streptococcal IgGBPs.

INTERPRETATION & CONCLUSION

The present data supported a role of streptococcal IgGBPs in the induction of myocardial tissue injury by GAS.