Counterimmunoelectrophoretic detection of a high incidence of precipitin reactions in normal human sera against staphylococcal teichoic acids and protein A.
The use of counterimmunoelectrophoresis (CIE) for detection of serum antibodies to staphylococcal teichoic acids was evaluated against teichoic acids prepared by sonic treatment or lysostaphin extraction of Staphylococcus aureus (Lafferty strain). Of 54 patient sera from suspected cases of staphylococcal endocarditis, osteomyelitis, or septicemia, 33 (61.1%) were positive by CIE analysis; however, 128 of 291 sera (44.0%) from normal adult donors were also positive. Selected CIE-positive sera from patient and control groups were titered by Ouchterlony gel diffusion. In the control group of normal sera, 65% were also positive by gel diffusion, but only 15% had titers of >/=1:2. Of the patient sera, 44.4% had gel diffusion titers of >/=1:2. In addition to the specific teichoic acid band, a second precipitation band could be demonstrated with both patient or normal sera by CIE or gel diffusion. This second precipitin band was shown to involve interactions of test sera with staphylococcal protein A present in the teichoic acid extracts. The protein A precipitins were detected at high concentrations of the antigen extracts, whereas the anti-teichoic acid precipitins were optimally detected at lower antigen concentrations. The formation of protein A precipitin bands did not correlate with the presence of anti-teichoic acid antibodies, as most sera tested were positive for protein A regardless of anti-teichoic acid activity. This study suggests that a high incidence of normal people have levels of antibodies to teichoic acids which are detectable by the highly sensitive, but nonspecific, technique of CIE. (+info)
Serological study of trichloroacetic acid extracts of Bacteroides fragilis.
Immunodiffusion techniques were used on trichloroacetic acid extracts from 10 strains of Bacteroides fragilis in detecting precipitating antibodies against this species in immune rabbit sera. Species and even strain specificities were observed in these precipitin reactions. Multiple antigens were detected in the extracts from some strains, whereas only one precipitin band per extract developed during agar-gel diffusion tests of others. The antigen extracts were found to be both heat stable and resistant to hydrolysis by alpha-chymotrypsin. Four serological patterns were demonstrated in homologous and heterologous reactions with the B. fragilis. antigen-antibody systems used. The results showed that some strains were serologically distinct from others, indicating that the strains tested are of more than one serotype. (+info)
Capsular polymer of Haemophilus influenzae, type b. I. Structural characterization of the capsular polymer of strain Eagan.
The capsular type-specific antigen of Haemophilus influenzae, type b, has been reported to have a unit structure composed of D-ribose and phosphate. Recently, the presence of ribitol was found in preparations of type b capsular antigen. Our analytical results show equimolar proportions of ribose, ribitol, and phosphate. Periodate oxidation studies, paper chromatography of acidic and alkaline hydrolysates, and NMR spectral data indicate the structure of the capular antigen of H. influenzae b, strain Eagan to be a polyribosylribitol phosphate polymer. (+info)
The value of tests for antibodies to DNA in monitoring the clinical course of SLE. A long-term study using the Farr test and the DNA counterimmunoelectrophoretic method.
Serial serum samples from fifteen patients with SLE, taken over periods varying from 6 months to 6 years, were tested for DNA binding capacity, DNA electroprecipitins (DNA-EP) and C'3 level to assess the value of these investigations in reflecting clinical disease activity. Patients with renal involvement showed a good correlation between high levels of DNA binding, low serum C'3 and disease activity and typically, their DNA-EP was negative. By contrast, patients without renal involvement in whom vasculitis was prominent, showed a poor correlation of DNA binding capacity to changes in the state of their disease although the DNA-EP test was persistently positive. It was also apparent that both the DNA-BC and C'3 can show marked variation in response to alterations in treatment without accompanying clinical change. Although these serological tests, particularly the DNA binding capacity are of recognized value in the diagnosis of SLE, they serve most usefully as guides to long-term management when they can be related to the clinical pattern of the disease. (+info)
Respiratory involvement in systemic lupus erythematosus. A clinical and immunological study.
Thirty patients fulfilling conventional criteria for systemic lupus erythematosus and who presented with extensive pleural and pulmonary involvement were studied retrospectively. Four overlapping patterns of respiratory disease were identified and observations were made on their clinical presentation, radiographic abnormalities and response to treatment. A low incidence of severe renal disease was found in this series of patients and this was in keeping with the general finding of low serum binding using native DNA in a globulin Farr-binding technique (greater than 20% binding in only 4/21 (19%) of the series) and normal or elevated serum complement (C3) levels. Precipitating antibody detected by double diffusion and counter-current immunoelectrophoresis and probably reacting in most cases with single-stranded DNA was, however, detected in 66% of pretreatment serum samples tested. This evidence supports the idea that different types of anti-nuclear antibody may be associated with different clinical manifestations seen within a group of patients who broadly fulfil the criteria for SLE. (+info)
Disease activity in the nephritis of systemic lupus erythematosus in relation to serum complement concentrations. DNA-binding capacity and precipitating anti-DNA antibody.
Serum C4 and C3 concentration and binding of double-stranded-DNA (ds-DNA) were measured in sera from ninety-nine patients with systemic lupus erythematosus and clinical evidence of nephritis. C3 and C4 concentrations correlated poorly with ds-DNA binding. In sera from fifty-three patients, precipitating antibody was sought using the counterimmunoelectrophoretic technique. Precipitating antibody was detected on at least one occasion in 44% of the patients, and these sera with precipitating antibody showed higher binding of ds-DNA and lower C4 concentrations than those without precipitating antibody. In thirty-two patients, serial assessments of the activity of the renal disease were made using decline or improvement in glomerular filtration rate, degree of proteinuria, oedema and hypertension as indices of "activity". All patients were receiving immunosuppressive drugs. Active nephritis was rarely found in patients showing, at that time, a normal serum C4 or normal ds-DNA binding; but a raised ds-DNA binding or lowered serum C4 were found in both active and inactive nephritis. There was no correlation of activity with serum concentrations of C3, or the presence or absence of precipitating antibody. We conclude that measurements of serum-complement concentrations and binding of ds-DNA are of most use in the diagnosis of systemic lupus erythematosus, and that in patients with nephritis and taking immunosuppressive drugs, these tests are of limited use in guiding treatment. (+info)
Computer simulation of immunochemical interactions.
A computer model for simulation of the interactions between a macromolecular antigen and its corresponding IgG has been developed. The model takes all possible immune complexes into account, and it calculates the most probable immune complex distribution patterns on the basis of basic thermodynamic principles from the valences and initial concentrations of antigen and antibody, respectively, together with an association constant assumed to be common to all mutual interactions. In antigen excess small antigen-rich complexes are predicted. At or near equivalence a rich variety of relatively small complexes is predicted, while in antibody excess complexes of the type AgAbn are found to be the most probable. By further assuming that the precipitate consists of antibody excess complexes, a precipitin curve can be calculated. The agreement between calculated results and experimentally obtained data is found to be good. It is of special interest that this theory implies that the outcome of immunochemical interactions depend equally well on the concentrations of antigen and of antibody. (+info)
Farmer's lung in Devon.
Farmer's lung is a cause of disability to agricultural workers in Devon and there is no evidence that the incidence is falling. A survey of known cases was made to assess the degree of disability in relation to the clinical history, the presence of farmer's lung precipitins, tests of lung function, and radiographic changes. Information was obtained about 200 patients diagnosed between 1939 and 1971. A survey of 148 of these patients showed that the disease was most commonly diagnosed in men aged 40 to 50 years and the most important symptom at diagnosis was dyspnoea related to occupational exposure to hay or grain. The onset was often insidious and only 67 patients (45%) were diagnosed during the first year of the disorder. Disability was severe in about one-third of the cases. The degree of disability did not seem to be related to the serological changes recorded either at diagnosis or at the time of our survey. Disability was commonly associated with restriction and reduced gas transfer factor and with airways obstruction in more severe cases. Many individuals reporting significant disability had only slightly abnormal ventilatory function tests at rest. Radiographic changes were found at survey in about one-third of the subjects reporting disability. Many farmers had not used an efficient mask. Treatment is unsatisfactory but steroid therapy is effective in acute episodes. (+info)