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R Peitrequin

Publications and source records attributed to R Peitrequin.

18 recordsLinked to original sources
PubMed1992

[Allergy to cockroaches in a Swiss population with asthma and chronic rhinitis].

Cockroach extracts are known to contain powerful allergens. In some parts of the world the majority of asthmatics have been shown to be allergic to cockroaches. We have evaluated the prevalence of sensitization to the cockroaches Blattella germanica and Trogoderma angustum in a Swiss population with chronic, non-seasonal asthma and rhinitis. The sera of 110 patients were screened for specific IgE by the RAST technique. We found 10 positive RAST (class 1 to 2). 7 of the 110 patients were sensitized to cockroaches (6.3%). 3 patients had positive RASTs for both species of cockroach. 2 patients had no other detectable allergy (= 5% of those who were considered as non-allergic before the study). These results suggest that allergy to cockroaches is uncommon in Switzerland but can sometimes be detected. We conclude that in Switzerland, screening for hypersensitivity to cockroaches should not be included in routine allergic investigations.

Adolescent↗
PubMed1991

Clinical evaluation of a new in-vitro assay for specific IgE, the immuno CAP system.

The Pharmacia CAP system is a new assay for specific IgE characterized by a new solid phase (hydrophilic polymer encased in a capsule). The CAP results were compared to those of the Phadebas IgE RAST and skin-prick tests (SPT) performed in 145 subjects suffering from rhinitis and/or asthma with eight common inhalant allergens (total number of tests = 1160). Concording CAP/RAST results were found in 91% of the tests. The CAP was positive in 78% and the RAST in 65% of the positive SPT. Conversely, the CAP was negative in 90.6% and the RAST in 96.4% of the negative SPT. A pattern negative SPT, negative RAST and positive CAP' was found in 56 tests (40 subjects): in four such subjects, the CAP positivity was confirmed by a positive IgE crossed radioimmunoelectrophoresis. Three borderline positive results were found among 240 negative controls (serum from cord blood or non-atopics). These data indicate that compared with SPT the CAP system is (a) more sensitive than the Pharmacia RAST and (b) does not seem less specific.

Adolescent↗
PubMed1989

Clinical evaluation of a new enzymo-assay for allergen-specific IgE.

A new assay for the determination of specific IgE in serum, using a monoclonal anti-IgE (Stallerzym), was evaluated. Compared with the results of skin prick tests, the Stallerzym was found to be 93% specific and 73% sensitive. In sera from patients selected to be either clearly allergic or not allergic (as defined by the concordant results of case history, skin prick test, and provocation test), Stallerzym proved to be as accurate and reliable as the Phadezym IgE RAST currently available.

Allergens↗
PubMed1988

Value of a new screening test for respiratory allergy.

Phadiatop (Pharmacia) is a new in vitro screening test for respiratory allergy which detects in serum the presence of specific IgE to a mixture of common inhalant allergens; results are either positive or negative. Among 100 patients suffering from rhinitis and/or asthma, investigated with 15 skin prick tests (SPT) and RAST for frequent allergens, the Phadiatop was positive in 63: all 63 had at least one positive SPT and RAST (specificity: 100%). Conversely, ther were 67 patients who had a positive RAST for at least one allergen: among these 67 the total IgE concentration in serum was high (greater than 100 kU/l) in 43 (64%) and the Phadiatop was positive in 63 (94%). Phadiatop was negative in serum obtained from 10 cord bloods and 10 non-allergic subjects (disease-free, 15 negative SPT and RAST). Results of the radio-immunoassay originally proposed by the manufacturer were similar to those obtained with a modified enzymo assay using a fluorometric substrate. In the prediction of respiratory allergy, Phadiatop was found to be specific and more accurate than the determination of total IgE in serum.

Adolescent↗
PubMed1988

Multidisc RAST: a reliable method for screening of specific IgE antibodies in serum?

"Multidiscs" (md) are cellulose discs to which several allergens are coupled, allowing the simultaneous screening of several specific IgE antibodies. We compared RAST performed with md to RAST performed with the corresponding individual allergens coated on single discs (sd). One hundred and twenty-two RAST positive samples were analyzed for four different allergen groups: moulds, cereals, weed pollens and tree pollens. We found lower RAST sensitivity when screening with mds than with the individual sds in all allergen groups except cereals. In 30 to 70% of the samples, the results were concordant. In 25.5 to 66.7%, md values were lower and in 1.3 to 26.3% higher than sd values. When only qualitative results were considered, the loss of sensitivity appeared acceptable: only 6.7 to 16.7% of the sd positive samples were not detected by md screening. A cost-benefit analysis, calculated on local data, confirmed economic advantages.

Cost-Benefit Analysis↗
PubMed1988

Identification of monoclonal gammopathies: a comparison of immunofixation, immunoelectrophoresis and measurements of kappa- and lambda-immunoglobulin levels.

We study whether immunoelectrophoresis (IE) could be replaced by immunofixation (IF) for the routine diagnosis of monoclonal gammopathies and/or by a quantitative measurement of kappa-resp. lambda-Ig levels in serum. The values of these measurements, together with the level of each Ig class, were used to calculate two ratios. IF, IE and calculation of both ratios were simultaneously applied to 153 serum samples. A monoclonal gammopathy (MGP) was found with all three methods in 51 cases and by none of them in another 51 cases. The first two techniques were positive and the third one negative in 16 cases. In 15 cases, IF showed the presence of a MGP, which was not or incompletely identified with IE, these results being associated with normal (7x) or abnormal ratios (8x). Nineteen cases with normal IF and IE had one or two abnormal ratios. After comparison with clinical data and outcome, we conclude that IF revealed 15 cases of MGP, which were not or only partially shown by IE. IE did not show any case of MGP not detected by IF. One of the ratios appeared as an interesting adjunct to the diagnostic procedure, but insufficient to be used as a single test. The other appeared to be of no diagnostic help. We conclude that immunofixation is the test of choice in the routine diagnosis of monoclonal gammopathies.

Diagnostic Errors↗
PubMed1987

[The hepatitis B vaccination campaign carried out from 1982 to 1984 using the Hevac B Pasteur vaccine among 6162 employees of Vaud hospitals].

6162 Swiss hospital employees were vaccinated against hepatitis B from 1982-1984 with Hevac B Pasteur vaccine. Vaccination was offered free of charge to 8471 employees, 72% of whom accepted a series of three injections and 50% a booster about 15 months later. Side effects, all benign, brief and rapidly resolved, were observed after 4% of injections in 7% of patients. Side effects after each of the three injections were noted in 0.7% of subjects. These figures are below those of other authors. -Concentrations of protective anti-HBs antibodies produced by the vaccination were measured by sampling of subjects. Four years after the beginning of the vaccinations the subjects had an average concentration of 87 mU/ml without booster and 595 mU/ml with booster. On average these concentrations are higher in employees more heavily exposed to hepatitis B than in the others. They are also higher in vaccines than in subjects immunized after natural infection, in whom they were 138 mU/ml. Production of anti-HBs antibodies was observed in 94% of subjects vaccinated.-In conclusion, the preparation used proved effective and well tolerated. This observation should help to foster more general use of vaccination campaigns in exposed populations.

Hepatitis B↗
PubMed1987

[Retrospective (1970-1984) serological study of delta antigen and antibody. Observations on seroconversion and absence of delta in non-A, non-B hepatitis].

335 serum samples collected between 1970 and 1984 from 278 HBsAg positive patients were tested for HDV antigen and HDV antibody (HDV = hepatitis D virus; also referred to as delta virus). The first positive sample was obtained in February 1974. The prevalence of the delta coinfection fluctuated in the following years between 0 and 52% of HBV-infected subjects. It was 40% on average in subjects at risk for HBV infection (i.v. drug abusers, homosexuals and institutionalized mentally retarded subjects) and 6% in persons without risk factors. The antibody was also found in 22% of subjects in a group of drug abusers who recovered from HBV infection (positive for anti-HBs antibody). The study showed that dissemination of HDV infection in Switzerland after 1974 was small clusters occurring mainly in drug users. It also showed that the infection was principally associated with chronic active hepatitis. In addition, sequential serum samples were taken from five patients with chronic hepatitis B superinfected by HDV, over periods of 2 to 13 months. Seroconversion (HDV antigen to HDV antibody) was observed in 4 of these 5 patients, with simultaneous presence of antigen and antibody for periods of 2 to 6 weeks. 167 samples from patients with non-A, non-B hepatitis were all negative for anti-delta antibody.

Adolescent↗
PubMed1987

Screening for anti-HTLV-III/LAV antibody in high-risk subjects: sensitivity and specificity of commercial tests.

1,834 serum samples from high-risk subjects were tested for anti-HTLV-III/LAV antibody by using the enzyme immuno assay (EIA) of Abbott (A), or the EIA of Abbott and Pasteur (P), or those two EIA plus Western blot analysis (WB). 983 samples were negative in A, 766 were strongly positive when tested in duplicate with both A and P, and 85 were slightly positive in A (23 samples) or discordant (62 samples) when tested further in P and WB. Of 62 discordant samples, 38 were reproducible. The pattern A+P-WB- was by far the most frequently encountered (26 samples) and interpreted as reflecting the higher incidence of positive results in the assay A. If one assumes that WB results are correct, the specificities of A and P are 93 and 100%, respectively (p less than 0.01), whereas the sensitivities are similar (98 and 99%).

Acquired Immunodeficiency Syndrome↗
PubMed1986

Application of microtitre plates and fluorescence reading to shorten handling of Phadezym RAST and Phadezym IgE PRIST.

To enable shorter and more convenient testing, the Phadezym RAST and Phadezym IgE PRIST procedures for the determination of specific and total IgE were modified in three ways: (i) allergen-coupled paper discs were tested in microtitre wells; (ii) the incubation times were reduced to 1 hr with serum and 2 hr with the anti-IgE by shaking the plates at room temperature; and (iii) the fluorogenic substrate used reduced the development time to 15 min. Determination of IgE antibody specific for fifteen inhalation allergens by the modified fluorescence test (FEIA) and by the conventional Phadezym RAST (EIA) was performed on the serum of thirty-two patients suffering from asthma/rhinitis: correlation studies for these sera showed that 96.1% of the results fell in the same class. In these patients, both FEIA and EIA detected the same proportion of skin-prick tests (SPT) positive results (67%). With the FEIA, 4/165 (2.4%) class 1 results were found in eleven non-atopic subjects (symptom free, fifteen negative SPT, total IgE lower than 80 kU/l), compared to 1/165 (0.6%) with the EIA. In twenty cord sera, both FEIA and EIA found 4/300 (1.3%) class 1 results. For the determination of total serum IgE, the microtitre FEIA showed a detection limit of 0.5 kU/l and an excellent correlation with Phadezym IgE PRIST (n = 66 serum, r = 0.99). These data indicate that the adaptation of Phadezym RAST and Phadezym IgE PRIST to microtitre plates and fluorescence technology has resulted in a time-saving and easy to perform within-day assay which provided results as reproducible, sensitive and specific as those of the conventional procedure.

Adolescent↗
PubMed1986

Comparison of two assays for the determination of specific IgE in serum of atopic and nonatopic subjects: the Allergenetics FAST and the Phadezym RAST.

The FAST assay (Allergenetics) for the determination of specific IgE has recently been introduced. The results of this test, graded in classes 0 (negative), 1 (equivocal) and 2 to 6 (positive) were compared with those of another commercially available test (Phadezym RAST, Pharmacia), graded from class 0 (negative) and classes 1 to 4 (positive). In 52 adults suffering from rhinitis/asthma, a total of 114 positive skin prick tests (SPT) were obtained for common respiratory allergens. In 67% of these tests the Phadezym RAST was positive and in 63% the FAST was positive (classes 2 to 6). In these patients there were 151 negative SPT: 6% corresponded to a positive Phadezym RAST (all class 1) and 34% to a positive FAST (classes 2 to 6). The serum of nine nonatopic volunteers who had negative SPT for 12 common allergens were tested. In none did the Phadezym RAST give any positive results; the FAST was positive in all nine sera, detecting between five and 11 allergens. When both assays were performed on 14 unselected cord blood samples, the Phadezym RAST was positive in three samples (with class 1 results to a maximum of two allergens), and the FAST was positive in 12 samples, detecting between one and seven allergens. Thus, in our hands, the FAST gave an abnormally high number of positive results in patients with negative SPT, in nonatopic volunteers, and in cord blood.

Adolescent↗
PubMed1983

Serodiagnosis of viral hepatitis A: rise in antibody titre and evaluation of three methods for detecting early and late antibodies.

A serological investigation was made on patients with viral hepatitis A and individuals with a past history of this disease. Titration of antibody in sequential samples was found to be of no help in diagnosis. Separation of early (IgM) from late (IgG) antibodies by protein A or by 2-mercaptoethanol did not prove to be convenient for the serodiagnosis. A chromatographic separation of late and early antibody was found to be satisfactory, and equivalent to a radioimmunoassay for IgM-antibodies.

Antibodies, Viral↗
PubMed1977

[Comparison between the presence of specific circulating immune complexes and the leukocyte migration inhibition test in different clinical forms of hepatitis B].

Circulating immune complexes were measured by a radioimmunoassay specific for HB complexes in different clinical situations related to hepatitis B virus infection. The leukocyte migration inhibition test (LMIT) was performed simultaneously. Comparison with the clinical situation suggests that immune complexes are not responsible for the lesions, but that these lesions might be produced by the immunity demonstrated by the LMIT. A deficiency of this immunity is responsible for the persistence of infection. However, in chronic active hepatitis, LMIT is as deficient as in carriers and in this form of hepatitis the frequency and quantity of complexes are the highest: it is thus possible that in this case the lesions are nevertheless produced by the complexes.

Antigen-Antibody Complex↗
PubMedDate not supplied

Absence of circulating HBsAg in acute hepatitis B.

We are describing five of a group of 72 cases of acute hepatitis B in which HBsAg was not present when the disease was diagnosed, i.e. two to six days after the appearance of icterus. The role of HBV infection was assessed by demonstrating the absence of anti-HBs during the first few weeks and its appearance at the time of recovery, as well as the presence of anti-HBe, high anti-HBc titers and the IgM class of immunoglobulin. The high levels of transaminases observed in early sera returned to normal values within two to six weeks. Anti-HAV antibodies were absent in all serum samples tested. These case reports should remind us that the absence of HBsAg at the onset of acute viral hepatitis does not exclude the possibility of HBV infection. Therefore, if HBsAg and anti-HAV are not present at the beginning of acute viral hepatitis, serum should also be tested for anti-HBc IgM before the diagnosis of non-A, non-B hepatitis is considered.

Acute Disease↗
PubMedDate not supplied

Anti-pre-S2 antibody response in subjects vaccinated against hepatitis B and in naturally immunized subjects.

Serum samples from individuals immunized with a pepsinized or non-pepsinized vaccine and from patients who had recovered from acute hepatitis B or who developed a chronic form of the disease, were analysed for the presence of antibody against the pre-S2 epitope of the hepatitis B virus. Anti-pre-S2 antibody was absent in all but one individual immunized with the pepsinized vaccine. Thirty-eight percent of the subjects who responded by anti-HBs production to the non-pepsinized preparation showed anti-pre-S2 antibody one year after complete vaccination. Among subjects who did not produce anti-HBs after immunization with this vaccine, 1 single individual produced anti-pre-S2 antibody. Anti-preS2 antibody was detectable after one year in 38% of the patients who recovered from acute hepatitis B, but in none of those with chronic hepatitis B. The kinetics of anti-pre-S2 antibody response to a booster injection was also analysed 1 month and 1 year after the 3rd injection and 1 month after the 4th injection of the non-pepsinized vaccine.

Acute Disease↗