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M M Brett

Publications and source records attributed to M M Brett.

27 records · Page 2Linked to original sources

The value of serum IgG titres against Pseudomonas aeruginosa in the management of early pseudomonal infection in cystic fibrosis.

We report the results of a clinical trial. Patients enrolled had serum IgG titres against Pseudomonas aeruginosa above the control range. Assignment to the observation or treatment group was by minimisation. Significant signs or symptoms in any patient prompted antipseudomonal treatment. In addition, the treatment group received antipseudomonal treatment at intervals of four months until the serum IgG titre returned to the control range. P aeruginosa was isolated intermittently from patients in the main trial. Nineteen patients were enrolled (12 observation, seven treatment). After one year in the trial changes in parameters studied, including forced expiratory volume in one second, IgG titre, serum IgG concentrations, and frequency of P aeruginosa isolation had improved in the treated group and worsened in the observation group.

Adolescent↗

Detection of Clostridium perfringens and its enterotoxin in cases of sporadic diarrhoea.

AIMS: To determine the incidence of sporadic and apparently non-food related diarrhoea associated with Clostridium perfringens enterotoxin. METHODS: Enzyme linked immunosorbent assay (ELISA) and reversed phase latex agglutination (RPLA) were used to detect C perfringens enterotoxin in faecal specimens from 818 sporadic cases of diarrhoea. RESULTS: C perfringens enterotoxin was identified as a cause of sporadic diarrhoea in 56 of 818 (6.8%) cases. Diarrhoea was prolonged (three days or more) in most cases. Ages ranged from 3 months to 89 years, although most patients were over 60 years of age. CONCLUSIONS: These results suggest that C perfringens may be a cause of sporadic cases of diarrhoea when causes such as food consumption or cross-infection are absent, particularly in the elderly.

Adolescent↗

Serum IgA antibodies against Pseudomonas aeruginosa in cystic fibrosis.

Serum IgA antibodies to Pseudomonas aeruginosa cell surface antigens were estimated by ELISA. Titres in patients with and without cystic fibrosis and with no pseudomonal infection were low (less than 105 to less than 261). Titres in patients with cystic fibrosis who were chronically infected with P aeruginosa were very high (1200-163,000), and patients who grew the organism intermittently had intermediate titres. Longitudinal studies suggested increasing tissue invasion or involvement of the lower respiratory tract, or both, with increasing time of infection and identified patients with a good prognosis after the onset of pseudomonal infection. Detection of an increased serum IgA titre can give an earlier indication than measurement of the serum IgG titre of the presence of P aeruginosa in the respiratory tract in a proportion of patients. IgA measurement seems to be better than IgG measurement at predicting the reappearance of P aeruginosa after apparent eradication of early infection. These results suggest that this assay may be a valuable additional indicator of the presence of P aeruginosa at the beginning of infection, and of the reappearance of the organism after treatment in the early stages of infection.

Adolescent↗

Prediction and diagnosis of early Pseudomonas aeruginosa infection in cystic fibrosis: a follow-up study.

Immunoglobulin G (IgG) antibodies to Pseudomonas aeruginosa surface antigens in serum were estimated by enzyme-linked immunosorbent assay for all patients from whom P. aeruginosa was isolated for the first time during a study period of 3 years (33 patients). The titer of IgG antibodies was greater than control values at or up to 24 months before the first isolation of P. aeruginosa in 24 patients. Another five patients had titers that were within the control range before isolation of P. aeruginosa but increased to above the control range within the following 2 months. In these 29 patients, continuing intermittent isolations of P. aeruginosa were accompanied by further increases in titer. The presence of a systemic immune response above the control range indicates tissue invasion and hence infection. Four patients were deemed to have no infection: one or two isolations of P. aeruginosa were accompanied by no increase in specific antibodies to above the control range throughout the entire study period. Fifteen patients received intravenous antipseudomonal chemotherapy. Eradication of the organism and a return of titer to control values, suggesting complete removal of the organisms, occurred in 5 patients, while continued isolations and only a partial decrease in titer occurred in 10 patients. The 15 patients who received treatment improved clinically, in contrast to untreated patients, whose clinical state worsened during the study period. Continuous steroid treatment, given to two patients, was accompanied by a dramatic decrease in both serum IgG concentration and titer, despite continuing intermittent isolations of P. aeruginosa. These results confirm and extend our earlier finding that this assay appears to detect P. aeruginosa infection at a very early stage and helps in differentiating between early infection and harmless colonization. It also appears to be a useful monitor of the progress of infection and the response to intravenous antibiotic treatment in these early stages of infection, before any clinical changes are sufficiently large to be detected, in patients who were not on continuous steroid therapy. The effect of steroid treatment on the immunological response and clinical outcome of patients with early P. aeruginosa infection requires further investigation.

Adolescent↗

An ELISA to detect antipseudomonal IgA antibodies in sera of patients with cystic fibrosis.

An enzyme linked immunosorbent assay (ELISA) to measure free serum IgA antibodies to Pseudomonas aeruginosa in patients with cystic fibrosis is described. Results were reproducible and there was no interference from crossreacting antibodies directed against other Gram negative bacteria. Titres were high in patients with Pseudomonas aeruginosa infection and differed according to the stage of the infection. These preliminary results suggest that this assay may be of value in assessing the state of Pseudomonas aeruginosa infection in patients with cystic fibrosis.

Adolescent↗

Serum IgG antibodies in patients with cystic fibrosis with early Pseudomonas aeruginosa infection.

Serum IgG antibodies to Pseudomonas aeruginosa surface antigens were measured by enzyme linked immunosorbent assay in all patients with cystic fibrosis from whom P. aeruginosa was isolated for the first time during a study period of 18 months. In 15 patients the titre of serum IgG antibodies was greater than control values before or at the time of the first bacteriological isolation of P. aeruginosa. The presence of serum antibodies specific to P. aeruginosa suggests exposure to infection by that organism for some months before its isolation in significant numbers from the respiratory tract. In the other two patients serum titres were within the control range before isolation of P. aeruginosa but had increased to above the control range within the next month. Longitudinal studies on the entire group of patients showed further increases in titre concurrently with further isolations of P. aeruginosa. These results suggest that this assay may be an indicator of the beginning of pulmonary infection by P. aeruginosa and may prove to be a sensitive monitor of the progress of infection, and response to treatment, during the first months of infection by that organism.

Adolescent↗

Serum antibodies to Pseudomonas aeruginosa in cystic fibrosis.

Serum IgG antibodies to Pseudomonas aeruginosa cell surface antigens were determined by enzyme linked immunosorbent assay. Titres in patients without cystic fibrosis were low (140-235). Those in patients with cystic fibrosis who were chronically infected by P. aeruginosa were very high (1100-20,500), while patients who grew the organism intermittently had lower titres (160-4400). Longitudinal studies showed that raised titres were observed at a very early stage of infection. High titres were associated with a poor clinical state, while low titres were associated with a better clinical state in both chronic and intermittently infected patients with cystic fibrosis. These results suggest that this test is a specific and sensitive measure of the severity and progress of the different stages of pulmonary infection by P. aeruginosa in patients with cystic fibrosis.

Adolescent↗

Development of enzyme linked immunosorbent assay (ELISA) to detect antibodies to Pseudomonas aeruginosa cell surface antigens in sera of patients with cystic fibrosis.

An enzyme linked immunosorbent assay (ELISA) to measure free serum IgG antibodies to Pseudomonas aeruginosa in patients with cystic fibrosis was developed. Seven strains of P aeruginosa cells, treated with glutaraldehyde and representing the most commonly isolated serotypes in our cystic fibrosis unit, were used. The specificity of the test was confirmed by the absence of cross reacting antibodies to other Gram negative bacteria. The results showed differences in the titres of antibodies at different stages of P aeruginosa infection. Because of its reproducibility, specificity, and sensitivity these preliminary results suggest that this test may be of value in monitoring the progress of P aeruginosa infection in patients with cystic fibrosis.

Adolescent↗