Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rheumatoid factors (RF) occur during the course of various infections such as leprosy, infective endocarditis, tuberculosis, trypanosomiasis, visceral larva migrans, infectious mononucleosis, influenza A, hepatitis A or cytomegalovirus. When first described it seemed logical to assume that host-self-immunization with autologous immune complexes provided the initial stimulus for RF production. Subsequently extensive characterization of bacterial, parasitic and viral Fc receptors has suggested an alternative explanation for rheumatoid factor associated with infections. It seems possible that patients make an initial immune response to infecting agent Fc receptors and that anti-anti-Fc receptors or anti-idiotypes either then directly stimulate rheumatoid factor production or are themselves rheumatoid factors. Such a hypothesis might also be applied to rheumatoid arthritis itself where either infecting agent or autologous cell Fc receptors could be the initial immunizing epitopes involved in rheumatoid factor production.
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PMID:Rheumatoid factors in subacute bacterial endocarditis and other infectious diseases. 307 Jul 27

In a retrospective study of 39 patients with infective endocarditis (IE) all had elevated concentrations of C reactive protein (CRP) at presentation, patients with the acute variety having significantly higher values than patients with the subacute variety. In addition, the majority of patients with subacute bacterial endocarditis had elevated concentrations of circulating immune complexes (CICs) and rheumatoid factor (RF), both of which were absent in all but one of nine patients with acute bacterial endocarditis. Two patients with subacute and one with acute bacterial endocarditis had low values of C3 and C4. Measurement of CRP, CICs, and RF did not distinguish between patients with and without extracardiac manifestations. Sequential analysis of patients revealed that a successful response to antimicrobial treatment was indicated by a striking and rapid decline in CRP, with less striking declines in CICs, RF, and IgM. Antibiotic failure was indicated by the persistence of high concentrations of CRP and CICs. We conclude that the measurement of C reactive protein is of some value in the diagnosis and management of infective endocarditis. A normal CRP concentration excludes this diagnosis. The measurement of CRP alone appears sufficient for monitoring most cases of infective endocarditis with the sequential measurement of rheumatoid factor and circulating immune complexes adding no useful information except where the CRP remains elevated despite treatment. In this latter instance, persisting high levels of CRP and circulating immune complexes together herald an ominous course.
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PMID:Serological investigations in the diagnosis and management of infective endocarditis. 347 Nov 92

We describe our 10 years experience in assaying over 15,000 clinical specimens for immune complexes (IC) using the C1q binding assay. Normal ranges were initially established using a large panel of blood donor sera and precision of the assay was optimized by inclusion of heat aggregated IgG (HAGG) as standards. Nevertheless some variability was observed due to variation in C1q binding from batch to batch and with aging of this reagent. In an empirically selected 2 year period involving over 3,000 clinical specimens, 25% had elevated concentrations of IC. Of these the majority were from patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), other connective tissue disorders, infective endocarditis (IE), diffuse interstitial lung disease (DILD) and vasculitis (VASC). In RA, IE and VASC, significant correlations were observed between concentrations of IC and rheumatoid factor (RF) and the addition of a purified monoclonal RF to normal serum caused increased C1q binding. Longitudinal studies in RA and IE demonstrated a striking decline in IC in response to effective treatment. We conclude that the measurement of IC provides little additional useful diagnostic information in those diseases associated with high levels of RF but appears more useful in disorders such as SLE, IE and DILD in which RF is absent or present in low concentration. Sequential monitoring of IC in RA and IE reflects response to treatment.
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PMID:Measurement of immune complexes with the liquid phase C1q binding assay: ten years experience in a routine diagnostic laboratory. 350 89

The sera of patients with bacterial endocarditis frequently contain high levels of circulating immune complexes. In in vitro assays these sera have been shown to be deficient in the complement mediated inhibition of immune precipitation (immune complex solubilization) although C3 and C4 levels were often normal. The deficiency is due to the presence of a factor which also inhibits the ability of normal serum to solubilize immune complexes. This inhibitor is possibly rheumatoid factor which is frequently detected in endocarditis. Serial studies on 16 patients showed the levels of immune complexes, the ability to prevent immune precipitation and rheumatoid factor to correlate with disease activity. The similarity of the findings to those in rheumatoid arthritis are discussed.
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PMID:Circulating immune complexes associated with decreased complement-mediated inhibition of immune precipitation in sera from patients with bacterial endocarditis. 369 38

Sixty episodes of infective endocarditis were analyzed in 56 pediatric patients over a 10-year period from 1974 to 1984. Culture-negative infective endocarditis was noted on five occasions or 8.3% of all episodes. In addition to the physical findings, a combination of laboratory parameters including anemia, erythrocyte sedimentation rate, elevated rheumatoid factor, C1q activation and microhematuria supported the diagnosis. The clinical characteristics of these patients are described in detail. Pretreatment with an antimicrobial agent was only one factor associated with the failure to isolate an organism. Empiric treatment with penicillin and gentamicin and in one case nafcillin/ampicillin and gentamicin was satisfactory.
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PMID:Incidence and clinical characteristics of "culture-negative" infective endocarditis in a pediatric population. 372 41

Low molecular weight (LMW) IgM is the monomeric subunit of pentameric IgM. It is not found in healthy adults but occurs in a number of autoimmune, lymphoproliferative and infectious conditions. It has not been described before in infective endocarditis (IE). Eighteen patients with IE were studied; 16 with subacute bacterial endocarditis (SBE) and two with acute endocarditis. LMW IgM was detected in the sera of six patients, all having SBE in association with circulating rheumatoid factor (RF). Of the remaining 12 patients without LMW IgM only three had RF in low quantities. Sequential studies revealed that LMW IgM appeared during the later stages of the illness at or following the peak RF and IgM response. LMW IgM was not detected in any of 20 control sera. Immunoblot analysis of sera containing LMW IgM revealed the presence of small quantities of dimeric and oligomeric IgM in addition to monomeric IgM. We conclude that LMW IgM occurs predominantly in those patients with IE who have associated RF. Immunoblot analysis suggests that the presence of monomeric and oligomeric LMW IgM reflects a disorder of IgM polymerization occurring in those patients.
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PMID:Appearance of low molecular weight IgM during course of infective endocarditis. 379 86

Mitral and aortic valves removed at emergency cardiac surgery from a patient with infective endocarditis caused by Streptococcus viridans were studied by immunofluorescence to ascertain the extent and pattern of various immune reactants within the large valvular vegetations. Heavy intravalvular deposits of IgG as well as bacterial antigen were present. Much more focal interstitial IgM and C3 deposits were noted within vegetations and valve substance. Diffuse endocardial and subendocardial deposition of C5b-C9 and C9 complement neoantigens was present. Direct staining of valvular tissues and vegetations for rheumatoid factor showed extensive interstitial tissue deposition. These findings emphasize the large amounts of immune reactants and constituents of immune complexes present in valves and vegetations of patients with infective endocarditis.
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PMID:Immunofluorescence studies of cardiac valves in infective endocarditis. 388 33

The authors describe 3 cases of left atrial myxoma confirmed by two-dimensional echocardiography and at operation. One patient had the symptoms of embolisms to the cerebral and renal vessels in the absence of heart disease, 2 patients presented with the symptoms of congestive heart failure. In one patient, loud first sound as well as systolic and diastolic murmur at the heart apex were documented. The nonspecific manifestations (weight loss, fever, high ESR, dysproteinemia, and rheumatoid factor) were observed in all the cases. The difficulties encountered in the clinical diagnosis of heart myxoma are discussed. The differential diagnosis is made between valvular heart disease and infective endocarditis, systemic vasculitis, cardiomyopathy, etc. Echocardiography to exclude myxoma should be performed in patients with thromboembolism, rheumatic valvular disease, subacute endocarditis (particularly in the absence of the classical symptoms) and in those with fever of unknown origin.
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PMID:[Clinical characteristics of myxoma of the heart]. 401 32

Human rheumatoid factors are antibodies of IgG, IgA, or IgM class that show reactions with antigenic determinants present on other immunoglobulin molecules. The most commonly measured rheumatoid factor relates to the 19S IgM type, which reacts by agglutination of latex particles coated with 7S IgG and is often measured in the standard latex fixation test. Approximately 65 to 70 per cent of patients with rheumatoid arthritis show positive serologic tests for rheumatoid factor; however, a number of other chronic disease conditions are also associated with positive rheumatoid factor reactions, including infective endocarditis, sarcoidosis, leprosy, and other hyperglobulinemic conditions. Although extensive serologic and immunochemical studies have identified a number of specific antigenic structural sites on immunoglobulin molecules that react with rheumatoid factors, recent studies have shown that a certain proportion of such antibodies may show cross-reactivity with DNA-histone complexes as well. It is still not entirely clear how rheumatoid factors fit into the pathogenesis of rheumatoid arthritis itself.
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PMID:Symposium on the immunodiagnosis of rheumatic and related diseases, Part II. Rheumatoid factors. 618 75

IgA and IgM rheumatoid factor activity, circulating immune complex levels, and antinuclear antibodies were measured in 17 patients with subacute or chronic infective endocarditis. Approximately three fourths of these patients had both IgA and IgM rheumatoid factors detectable by radioimmunoassay, and IgA and IgM rheumatoid factor activity was strongly correlated (p less than 0.01). In three patients studied, IgA rheumatoid factor activity was predominantly polymeric as assessed by sucrose density ultracentrifugation (55 to 92 percent of total rheumatoid factor activity) and could bind radiolabeled secretory component. No correlations between rheumatoid factor activity and circulating immune complex levels or antibodies to nuclear antigens were observed. These observations indicate that circulating polymeric IgA antibodies do not necessarily signify a mucosal stimulus for IgA production and also demonstrate differences in the intensity and spectrum of autoantibody production when compared with autoimmune diseases.
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PMID:Induction of polymeric IgA rheumatoid factors in infective endocarditis. 660 83


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