Biomedical subjects

C H Bridts

Publications and source records attributed to C H Bridts.

At least 73 records · Page 4Linked to original sources

PubMed1989

Pitfalls with anti-neutrophil cytoplasmic antibodies (ANCA).

A 39-year-old Ugandan student is described presenting with general malaise, fever and a pulmonary infiltrate. Open lung biopsy showing infarction and positive ANCA lead to a diagnosis of Wegener's granulomatosis and a treatment with immunosuppressive drugs was instituted. Five weeks after admission, however, sputum cultures turned out to be positive for Mycobacterium tuberculosis. The importance of ANCA-interpretation and the possibility of false positive results is discussed.

Adult↗

PubMed1989

Inhibition of natural killer cell activity by retroplacental sera as compared to peripheral sera. Lack of influence of immune complexes.

A decrease of natural killer cell activity (NKCA) during human pregnancy might contribute to the acceptance of the allogeneic fetus by the maternal host. The inhibition of NKCA might be due to serum factors derived from the trophoblast. We focused especially on the role of immune complexes, as it has already been described that these complexes depress NKCA and as they are found frequently in retroplacental serum. We have compared the influence of 19 paired retroplacental and peripheral blood sera on NKCA of normal donors. One peripheral and eight retroplacental sera contained immune complexes. Normal donor mononuclear cells were incubated with carboxyfluorescein-labeled K562 cells in the presence of retroplacental serum or peripheral serum. NKCA was measured on a FACS Analyzer. Ten of 19 retroplacental sera inhibited NKCA significantly in comparison to the corresponding peripheral serum (P = 0.003). There was no correlation between NKCA and the immune complex level. We conclude that, as compared to peripheral serum taken at delivery, there is a retroplacental serum-induced inhibition of NKCA, which is not correlated with the presence of immune complexes.

Antigen-Antibody Complex↗

PubMed1988

A useful method for determining class-specific rheumatoid factors with computerized analyses of data.

A simple and sensitive enzyme-linked immunosorbent assay (ELISA) was developed to determine rheumatoid factors (RFs) of IgG, IgA and IgM class. Standardisation was performed with a standard reference serum for IgM-RF, calibrated according to the WHO preparation, and with the serum of a patient containing high levels of IgA- and IgG-RF. The sigmoidal shaped calibration curve was fitted with a computerized four parameter logistic model with simplified mathematical computations. This method provided to be more accurate for measuring RF levels, as judged by the smaller residuals, than logit or log-linear transformations. The considerable reduction in processing time, which is obtained by the computerized analysis of data, makes this method of class-specific RF determination suitable for routine analysis.

Enzyme-Linked Immunosorbent Assay↗

PubMed1988

Neutrophil activation by IgE-containing circulating immune complexes of patients with connective tissue diseases.

In an earlier study, we reported IgE-containing circulating immune complexes (CICs) in 66.6% of the patients with rheumatoid arthritis who were studied, especially in those with extra-articular manifestations. The present study was undertaken to examine the possible role of these immune complexes in inflammatory cell activation. Twelve patients with classic or definite rheumatoid arthritis, two with primary Sjögren's syndrome, and three patients with systemic lupus erythematosus were studied. Of these 17 patients, 10 were IgE-containing CIC positive, and seven patients were IgE-containing CIC negative. Polyethylene glycol-precipitated IgE-containing CICs and IgG-containing CICs of these patients were coated on plastic wells and incubated with suspensions of neutrophils. As a parameter of cell activation, superoxide release (SOR) was measured by cytochrome C reduction in the supernatant after 30, 60, and 90 minutes. There was a significant SOR up to 38% of the zymosan control when IgE-containing CICs were incubated with neutrophils. Furthermore, there was a significant correlation between the level of IgE-containing CICs and the amount of SOR, but not between the level of IgG-containing CICs and the amount of SOR. These results suggest a possible role for IgE-containing CICs in the activation of inflammatory cells in connective tissue diseases.

Antigen-Antibody Complex↗

PubMed1988

Immune complexes and Pseudomonas aeruginosa antibodies in cystic fibrosis.

Serum samples from 57 patients with cystic fibrosis were tested for the presence of IgG, IgA, IgM, IgE, and circulating immune complexes containing IgG, IgA, and IgM. Titres of class specific antibodies to Pseudomonas aeruginosa, and class specific antibodies to Ps aeruginosa in circulating immune complexes, were also measured. According to the Shwachman score the patients were divided into three clinical groups: group 1-moderate and severe disease, group 2-mild disease, and group 3-well. The results of the immunological investigations were correlated with the clinical state of the patients as assessed by the Shwachman score. Serum concentrations of IgG, IgA, and IgM were inversely correlated with the Shwachman score, but the differences between the groups were only significant for IgG and IgA. The same correlations were found for circulating immune complexes containing IgG and IgA. Antibodies to Ps aeruginosa could be detected in most of the patients' serum samples. IgA antibody specific to Ps aeruginosa was the most often raised, even in patients in group 3. It is therefore suggested that IgA antibody specific to Ps aeruginosa could be an early marker of colonisation by Ps aeruginosa and a sensitive measurement of infection with Ps aeruginosa in young children with cystic fibrosis. Moreover, in the circulating immune complexes, class specific antibodies to Ps aeruginosa were found in nearly half the patients. The highest titres of IgG and IgA antibodies specific to Ps aeruginosa in the circulating immune complexes were detected in the patients with the worst clinical state (group 1).

Adolescent↗

PubMed1988

Role of IgM-rheumatoid factor interference in the determination of total serum IgE and IgE-containing circulating immune complexes.

IgM-rheumatoid factor (RF) interference in the determination of total serum IgE and IgE-containing circulating immune complexes (IgE-CIC) was studied by inhibition experiments in vitro comparing a new ELISA technique free of IgM-RF interference with more widely used RIA methods. It was shown that a considerable overestimation of the IgE content in CIC can exist when high levels of IgM-RF are present in the same serum. The clinical part of this study revealed a dramatic fall in prevalence of IgE-CIC in patients with rheumatoid arthritis (RA) with the ELISA technique, compared with the more conventional RIA method (respectively 1/20 compared to 12/20 positive for IgE-CIC). In these patients, there was a good correlation between the level of IgM-RF and the amount of IgE detected in the CIC by the RIA method (r = 0.87) whereas the RF-interference free ELISA method showed no correlation between these two parameters (r = 0.06). Total serum IgE determination with a solid phase RIA was also influenced by IgM-RF interference, whereas the PRIST method was not affected by the presence of IgM-RF. In conclusion, in patients with rheumatic diseases, IgE-assays using polyclonal rabbit or sheep anti-IgE antibodies are not appropriate and monoclonal anti-IgE antibodies that have been proved not to interfere with IgM-RF should be advocated.

Antigen-Antibody Complex↗

PubMed1985

Clinical and biological evaluation of semi-rush and ordinary immunotherapy schemes in type I allergic respiratory diseases.

Forty-three patients with type I allergic respiratory diseases received aqueous grass pollen immunotherapy in a prospective study designed to compare the clinical and biological effects of a semi-rush hyposensitization (20 patients) with ordinary hyposensitization (23 patients). Before the start of the therapy (end of previous grass pollen season, t1) and before (t2) and after the next grass pollen season (t3), total serum IgE (tIgE), grass pollen-specific IgE (GPsIgE), grass pollen-specific IgG (GPsIgG) and complement factors C3 and C4 were determined. GPsIgE and GPsIgG levels increased significantly more during immunotherapy in patients receiving the semi-rush scheme as compared with the ordinary scheme. There were no significant changes between the two schemes at any times for tIgE, C3 and C4. GPsIgG was already higher in allergic patients before the start of therapy as compared with non-allergic patients and controls. Clinical improvement was the same in patients treated with the semi-rush scheme as in the ordinary group. The number of side effects was not statistically different between the two groups. In neither group was there a correlation between the change in biological parameters and change in clinical symptoms. As the semi-rush scheme gives the same results immunologically as well as clinically, it could be used in a number of patients since it reduces the time course of the initial therapy by about 2 months.

Adult↗

PubMed1985

IgE deposition in normal skin of patients with rheumatoid arthritis in relation to clinical and laboratory findings.

Biopsy specimens from apparently normal skin of 28 patients with classical or definite rheumatoid arthritis (RA) were examined for the presence of IgE deposition by a direct immunofluorescence technique. IgE deposition was found in 12 patients (43%) and in none of the 10 controls. This deposition was mainly localised on mast cells, and in three patients perivascular IgE staining was also noted. The skin from nine of the 12 patients also showed deposition of IgM and complement C3 or C4 factor, or both. All 12 patients with skin IgE deposition had raised levels of IgM rheumatoid factor (RF) in the serum. Nine of these also had IgE RF. IgE-containing circulating immune complexes (IgE CIC), raised serum IgE levels, and extra-articular (EA) manifestations were present in respectively 10, nine, and eight skin IgE positive patients. It is suggested that IgE and IgE CIC may be involved in the pathogenesis of RA and its EA manifestations.

Adult↗

PubMed1984

IgG-containing and IgE-containing circulating immune complexes in patients with asthma and rhinitis.

In looking for an additional mechanism that could cause inflammation and therefore be important in the pathogenesis of asthma and rhinitis, IgG- and IgE-CIC were determined in a number of patients that were suffering from asthma and/or rhinitis. Patients were further subdivided into allergic (type I allergy) and nonallergic patients on the basis of history, skin testing with common inhalant allergens, RAST, and, if necessary, allergen provocation. In addition, a control group and patients that were undergoing allergen-specific hyposensitization were studied also. The mean level and frequency of elevated IgG-CIC were significantly increased in all three patient groups as compared to controls. The frequency of IgE-CIC was only significantly elevated in both allergic groups, and the difference between allergic and nonallergic patients was highly significant. IgG- and IgE-CIC did not increase during long-term allergen hyposensitization. Since there was no significant increase of IgE-CIC 10 min after bronchial allergen challenge nor at the moment that symptoms such as urticaria, bronchial obstruction, or rhinorrhea appeared during rush hyposensitization in asthmatic patients, we think that CIC are not involved in classic type I allergic reactions. The possible role of IgG- and IgE-CIC in inducing inflammatory, mediator release from eosinophils and macrophages via binding of Fc receptors on these cells is discussed.

Antigen-Antibody Complex↗

PubMed1983

Effect of chemotherapy and reinfection on IgE-containing and IgG-containing circulating immune complexes, serum IgE and IgE antibodies in patients chronically infected with Schistosoma mansoni and Schistosoma haematobium.

The effect of chemotherapy and reinfection on circulating immune complexes (CIC), serum IgE, and parasite-specific IgE antibodies was studied in patients concomitantly infected with Schistosoma mansoni and Schistosoma haematobium. Before chemotherapy IgE- and IgG-containing CIC were present in high concentrations in all patients and IgE antibodies to S. mansoni and to S. haematobium in almost 80% of the cases. Serum IgE was excessively high (median 4,900 ku/1), but decreased to half of its initial value 2 months after chemotherapy. When reinfection with S. haematobium occurred onwards from month 4, the serum IgE reincreased and reached almost the pretreatment level at month 16. Effective chemotherapy was also followed by a rapid decrease of IgE-containing CIC and a slower, but significant, decrease of IgG-containing CIC. However, in contrast to IgE and IgE antibodies, the reinfection did not lead to a reincrease of CIC. It was interesting to note that the concentration of IgE as well as that of IgE-containing CIC was significantly correlated to the intensity of the infection. These investigations demonstrated that high levels of IgE- and IgG-containing CIC are present in chronic human schistosomiasis, but that the concentrations of CIC fall to normal values, when the parasites are eliminated by chemotherapy.

Antigen-Antibody Complex↗

PubMed1983

IgG and IgE circulating immune complexes, total serum IgE and parasite related IgE in patients with mono- or mixed infection with Schistosoma mansoni and/or S. haematobium. Influence of therapy.

IgG and IgE containing circulating immune complexes (CIC), total serum IgE and parasite related IgE were determined in monoinfected patients with Schistosoma mansoni or S.haematobium and in patients with a mixed infection. IgE- and IgG-CIC and total serum IgE were significantly higher in the mixed infection group. There is considerable cross-reactivity between the crude S.haematobium and S.mansoni antigen preparations. The level of IgE-CIC is correlated to the levels of total serum IgE and parasite related IgE respectively. Furthermore IgE-CIC levels were related to the intensity of infection. Twelve out of 21 patients suffering from a monoinfection were reinvestigated 1-4 months after specific chemotherapy. Parasitological cure is followed by a significant decrease of total serum IgE and IgE-CIC, whereas parasite related IgE did not change significantly. The importance of the disappearance of IgE-CIC is discussed.

Adolescent↗

PubMedDate not supplied

Is the prevalence of specific IgE to classical inhalant aeroallergens among patients with respiratory allergy changing? Evidence from two surveys 15 years apart.

OBJECTIVE: The aim of this study was to evaluate the relative frequencies of sensitisation to four common inhalant allergens in two atopic populations suffering from asthma and/or rhinitis. One had been studied in the period of 1975 till 1979, and a second population was evaluated between 1992 and 1995. DATA SOURCES: At both time periods patients with inhalant allergy and visiting our outpatient clinic were included. Quantification of IgE to Dermatophagoides pteronyssinus, birch, timothy grass, and mugwort was performed via the Phadebas RAST technique (Pharmacia, Brussels, Belgium). RESULTS: In patients suffering from respiratory allergy the frequency of birch pollen sensitisation significantly increased from 13% in the period 1975-1979 to 34% in the period 1992-1995. In contrast, the frequency of house dust mite, timothy grass pollen, and mugwort pollen sensitisation remained almost unchanged. The increase was not associated with an increase in the birch pollen count. CONCLUSION: Birch pollen hypersensitivity has almost tripled among atopic subjects during the last 2 decades. The exact mechanisms for this increase remain to be evaluated.

Allergens↗

PubMedDate not supplied

The prevalence and diagnostic value of specific IgE antibodies to inhalant, animal and plant food, and ficus allergens in patients with natural rubber latex allergy.

BACKGROUND: It is well recognised that natural rubber latex allergy can be associated with serological cross-reactivity to plant allergens, especially tropical fruits and Ficus. In contrast, data on the frequency and clinical value of specific IgE antibodies against these allergens remain rare. In addition, little is known about the prevalence and diagnostic value of specific IgE antibodies to classical inhalant and animal allergens in NRL allergic patients. OBJECTIVE: The purpose of this study was to investigate the prevalence, the sensitivity, and the specificity of these different specific IgE antibodies in patients suffering from NRL allergy. METHODS: Serum samples of 42 NRL allergic adults were investigated. All had a history of NRL allergy confirmed by a positive skin test for latex and a positive latex-specific IgE. Samples were analysed for IgE antibodies against 9 plant food allergens (avocado, banana, chestnut, fig, kiwi, papaya, peanut, pineapple and tomato) and Ficus benjamina. A specific IgE quantification for 3 animal food allergens (codfish, cow's milk, egg's white) and 8 common inhalant allergens (Dermatophagoïdes pteronyssinus, birch pollen, timothy grass pollen, mugwort pollen, cat and dog epithelium, Aspergillus fumigatus and Cladosporium herbarum) was also performed. Because double blind placebo-controlled challenges could not be considered, for ethical reasons, patient's food allergy or immediate hypersensitivity for Ficus and inhalant allergens was documented by a standardised questionnaire. Diagnosis of atopy was based on a relevant history and the presence of a specific IgE antibody to at least one classical inhalant allergen. For some IgE determinations presence or absence of cross-reactivity was investigated by CAP-inhibition tests. RESULTS: A specific IgE antibody to at least one of the investigated inhalant and animal food allergens was found in respectively 76% and 12% of the serum samples. A plant food-specific IgE antibody was observed in 88% of the serum samples, most frequently to papaya (71%) and least frequently to kiwi (17%). Twenty-nine percent of the serum samples contained Ficus-IgE. According to the questionnaire and the threshold of 0.35 kUa/L, sensitivity of the plant food IgE antibodies varied between 0% for papaya and 73% for avocado. Specificity varied between 28% for papaya and 91% for kiwi. For Ficus-IgE sensitivity was 20% and specificity 70%. CONCLUSIONS: For inhalant and animal food allergens sensitivity and specificity of the IgE quantification correlated generally well with the values obtained in non-NRL allergic adults. Determination of specific IgE to the investigated plant foods and Ficus was not always a sensitive neither a specific test to establish the clinical diagnosis of this allergy.

Adolescent↗

PubMedDate not supplied

Allergic reactions occurring during anaesthesia: diagnostic approach.

Anaphylactic and anaphylactoid reactions to anaesthetic and associated agents used during the perioperative period have been increasingly reported during the last 3 decades. The frequency of life-threatening hypersensitivity reactions occurring during anaesthesia has been estimated to vary between 1/1.000 and 1/25.0000 procedures, with muscle relaxants being involved in almost three quarters of the cases. The mortality from these reactions is in the range of 3-6%. Nowadays, natural rubber latex also accounts for a significant number of perioperative anaphylaxis, particularly in children. Clinical manifestations do not allow to differentiate between IgE-mediated anaphylaxis and anaphylactoid reactions resulting from non-specific mediator release. Successful management of these patients requires multidisciplinary approach and includes prompt recognition and stabilisation of the acute event by the attending anaesthetist, determination of the responsible agent(s) with avoidance of subsequent administration of incriminated compound(s). The latter is based upon correct identification of the responsible drug and potentially cross-reactive compounds by the allergist and requires a detailed review of the anaesthetic report as well as appropriate in vitro and in vivo allergy tests. At present, the overall performance of skin tests makes them the "gold standard" for diagnosis of muscle relaxant-induced perioperative hypersensitivity reactions. In addition, given their good negative predictive value, skin tests have been proven to be a useful tool to tailor the appropriate therapeutic alternative. For other compounds diagnosis is more difficult but newer techniques such as analysis of in vitro activated basophils can be helpful.

Anesthesia↗

PubMedDate not supplied

Anaphylaxis to an urethral lubricant: chlorhexidine as the "hidden" allergen.

We report on a severe allergic reaction during urethral catheterisation, initially erroneously attributed to natural rubber latex (NRL). However, the negative investigations for latex, the uneventful further applications of NRL, the positive skin test and basophil activation test for chlorhexidine strongly support diagnosis of chlorhexidine anaphylaxis. This case illustrates that it is not widely appreciated that "innocent" products such as urethral lubricants may elicit serious life-threatening reactions. Careful inspection of the medical records is once again re-emphasised to be mandatory in order to avert subsequent anaphylaxis.

Aged↗

PubMedDate not supplied

Immediate-type allergy to drugs and related compounds: evaluation and management.

Adverse drug reactions (ADR) constitute a major health issue in outpatient and inpatient clinical settings. An allergic drug reaction is an immunologically mediated adverse drug reaction that exhibits specificity and recurrence on re-exposure to the offending and/or cross-reactive compound(s). Diagnosis of drug allergy is difficult, as a broad spectrum of different drugs can elicit various immune-mediated diseases with distinct (sometimes unclear) pathomechanism, the exact structure (epitope) that causes the reaction is frequently unknown, the presence of an in vitro or in vivo test results might not be predictive of a clinical situation, and the gold standard or reference test for diagnosis, the drug challenge, is a complicated and sometimes dangerous endeavour. Nevertheless, during the past few years serious attempts have been made to standardise and validate in vitro and in vivo techniques for the diagnosis of drug allergy. New techniques, e.g. flow-assisted analysis of in vitro basophil activation, are replacing older ones like histamine release for immediate-type hypersensitivity reactions. However, additional comprehensive studies are required to further validate the technique and allow its entrance in mainstream diagnostic use, particularly for non-IgE-mediated hypersensitivity. This review attempts to summarize the major causes of immediate hypersensitivity reactions to drugs and related compounds. Special attention is paid to the diagnostic and therapeutic management of this common iatrogenic complication.

Drug Hypersensitivity↗

PubMedDate not supplied

Coriander anaphylaxis in a spice grinder with undetected occupational allergy.

BACKGROUND: Anaphylaxis after ingestion of spices as a result from occupational sensitization remains anecdotal. We describe a patient, working in a spice factory, with anaphylaxis from coriander in a meal. He also demonstrated urticaria, angio-edema, rhinoconjunctivitis and bronchospasm during handling coriander and fenugreek. OBJECTIVE: To determine the mechanism of the anaphylactic reaction and to evaluate cross-reactivity between both botanically unrelated spices. METHODS: Investigations comprised quantification of total and specific IgE by Immuno-CAP FEIA, skin testing, basophil activation experiments by flow-assisted determination of CD63 expression in the patient and 3 healthy controls. Immuno-CAP inhibition experiments were applied to investigate cross-reactivity. RESULTS: Specific IgE, skin tests and basophil activation tests were clearly positive in the patient, whereas they remained negative in controls. No cross-reactivity between fenugreek and coriander was demonstrable by inhibition experiments. CONCLUSIONS: The clinical manifestations in temporal relationship to ingestion of coriander and handling of coriander and/or fenugreek, the positive specific IgE results, skin tests and basophil activation assays support the diagnosis of allergy to both spices. History suggests sensitization by occupational exposure.

Adult↗

PubMedDate not supplied

Influence of cyclic intravenous pamidronate on proinflammatory monocytic cytokine profiles and bone density in rheumatoid arthritis treated with low dose prednisolone and methotrexate.

OBJECTIVES: The aim of this work was to evaluate in a randomised double-blind prospective study the effect of pamidronate on intracellular monocytic cytokine profiles (IL-1, IL-6, TNF-alpha) and bone density in rheumatoid arthritis patients. METHODS: Twenty rheumatoid arthritis patients were treated for one year with methotrexate and a low dose of prednisolone. Double blind randomisation was performed for either i.v. pamidronate (at 3-month intervals) or placebo. The effect of pamidronate was evaluated on intracellular cytokine profiles (IL-1, IL-6, TNF-alpha), disease activity and bone mass measurements. The human monocytic cell line THP-1 was used to evaluate in vitro apoptosis by pamidronate. RESULTS: Spontaneous production of interleukin-1 beta by patient blood monocytes was lower in the pamidronate group and was associated with an increase in bone density of the spine after 12 months of therapy. In vitro a dose-related increase in pamidronate induced apoptosis was found in THP-1 cells. CONCLUSIONS: This prospective double-blind randomised study demonstrated that pamidronate therapy resulted in an increase of bone density despite treatment with steroids. This rise is associated with a suppression of interleukin-1 beta production in monocytes of patients treated with pamidronate. Our in vitro experiments suggest that this anti-inflammatory effect could be due to an increase in the apoptosis of monocytic cells.

Adult↗