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Biomedical subjects

C M Luczynska

Publications and source records attributed to C M Luczynska.

At least 19 recordsLinked to original sources

Serum eosinophil cationic protein: distribution and reproducibility in a randomly selected sample of men living in rural Norfolk, UK.

BACKGROUND: It has been proposed that serum levels of eosinophil cationic protein (ECP) may be a clinically useful measure in allergic illness. The aim of this report is to describe the distribution and reproducibility of serum ECP levels in a population sample and to examine its relationship with other markers of disease. METHODS: The study was conducted in rural areas of Norfolk, UK in a random sample of men aged 20-44 years enriched with subjects drawn from general practice 'asthma registers'. Asthma symptoms were assessed using the EC Respiratory Health Survey questionnaire. Atopy was measured by skin prick tests and serum IgE. Airway hyperresponsiveness (AHR) was tested by methacholine challenge test. Serum IgE and ECP was measured by fluoroimmunoassay using the Pharmacia CAP system. Reference equations were derived in subjects from the random sample who did not have symptoms of asthma, abnormal lung function or AHR. The relation of serum ECP with various clinical characteristics was examined in the whole study population. Reproducibility of serum ECP measurement was assessed in 57 subjects 4 weeks after the initial test. RESULTS: The study population comprised 311 from the random sample and 58 from the asthma sample. The reference equation for serum ECP for healthy men was log10 ECP = 1.3966 - [(age - 20) x 0.0057]. The estimated mean serum ECP for a 20-year-old man was 25 microg/L. Current smokers have higher serum ECP levels that non-smokers (P = 0.014). ECP levels were not related to the skin prick test reactivity, serum IgE, a questionnaire-based diagnosis of asthma, or impaired lung function (all P > 0.05). Levels were higher in subjects with AHR (P = 0.003) and those who reported wheeze (P = 0.017) but there was no clinically useful separation in ECP levels between subjects classified by these criteria. The test was moderately reproducible over a 4-week period (intraclass correlation coefficient = 0.62). DISCUSSION: Serum ECP levels were higher in this rural English population than reported in a comparable population in Sweden. Serum ECP is a reproducible test but cross-sectionally does not relate in any clinically useful way to markers of asthma. The meaning of between- subject differences in ECP levels requires further exploration.

Adult↗

Identification and quantification of mite allergens.

Allergens from the house dust mite are ubiquitous in house dust. Exposure to these allergens can cause acute symptoms in patients who are sensitized to house-dust mite and have asthma or other allergic diseases, such as rhinitis or atopic dermatitis. It is not clear how much mite-allergen exposure is a risk factor for the development of sensitization or for triggering acute symptoms. Therefore, it is important to be able to quantify accurately the amount of mite allergen present in the indoor environment in order to carry out studies to identify risk factors for exposure, to investigate exposure-response effects, and to monitor the progress of allergen-reducing regimens.

Allergens↗

Variation in nebulizer aerosol output and weight output from the Mefar dosimeter: implications for multicentre studies.

The active aerosol component of nebulizers is less than 100% of output by weight, and may vary between nebulizers in different batches from the same manufacturer. A measure of bronchial responsiveness to methacholine, which can overcome this problem, is required. One hundred and sixty nebulizers from 21 centres in the European Community Respiratory Health Survey (ECRHS) were calibrated for aerosol and weight output. Methacholine challenge data were obtained for 1,021 subjects in three English centres of the ECRHS. The dose producing a 20% fall in forced expiratory volume in one second (PD20), and log-slope, the regression slope of percentage decline in FEV1 with log (dose), were calculated, with and without calibration of nebulizers by weight. Within-centre variation in nebulizer percentage aerosol output had a coefficient of variation of less than 10%. Unlike PD20, log-slope is unaffected by constant percentage overestimation of nebulizer output. Variation in output by weight of nebulizers of 10% had little affect on log-slope. It is, however, affected by the scheduled range of doses. Log-slope shows advantages in analysis, and is less affected by variation in nebulizer output. It can be used for multicentre comparisons, with restriction to a common dose protocol.

Aerosols↗

Measuring atopy in a multi-centre epidemiological study.

Skin prick tests are used as a measure of atopy in epidemiological studies, but results may be influenced by the fieldworker performing the test. In a multi-centre epidemiological study the method of reporting the results should consider the need for comparability of findings from different centres. Data on over 1000 subjects from three English centres of the European Community Respiratory Health Survey were analysed to determine whether allergen wheal should be adjusted for histamine wheal, and what cutoff diameter gave the most comparable results. No consistent relation between allergen wheal diameter and histamine wheal diameter was found for any fieldworker or allergen. A cutoff of > 0 mm for a positive result gave a more consistent relation with the corresponding specific IgE value between fieldworkers than either a cutoff of > or = 3 mm or the use of the mean wheal diameter. While this result is not immediately generalisable to studies using different skin prick test reagents, the method of analysis to determine the appropriate criterion of reporting can be used in other epidemiological studies.

Adult↗

Adjustment of reported prevalence of respiratory symptoms for non-response in a multi-centre health survey.

BACKGROUND: Estimation of non-response bias by modelling prevalence as a function of the number of mailings required to achieve a response, or of the cumulative response, has been advocated, but the models have not incorporated age and sex, differential response rates by age and sex, or season of response. METHODS: The effect on age-sex standardized prevalence of estimating non-response bias using a variety of models was investigated using data on nine symptom and medication questions from 13,007 subjects in the three English centres of the European Community Respiratory Health Survey. Comparison was made of goodness of fit and the prediction of responses in a 25% follow-up sample with the observed values. RESULTS: Despite low response rates in Cambridge and significant decreases in prevalence with additional mailings or increasing cumulative response in Norwich, there were only small effects on estimated age-sex standardized prevalences. No model was consistently better for any centre or question. CONCLUSIONS: The models are useful for exploring the sensitivity of estimated prevalence to non-response bias, but should be used with caution to adjust estimates. Ideally first mailings should be staggered over the whole year so that mailing and season are not confounded, and sufficient mailings or other contacts carried out for the whole sample to ensure a high response rate.

Adult↗

The effect of vacuum cleaners on the concentration and particle size distribution of airborne cat allergen.

BACKGROUND: Vacuum cleaners are essential for the removal of dust from the surface of carpets; however, they may also contribute to airborne dust both by leakage through the cleaner and disturbance of floor dust. METHODS: The present studies used established techniques for measuring airborne Fel d I to study the effects of vacuum cleaners on airborne cat allergen under laboratory conditions and in houses with cats. Nine different models were loaded with dust containing 50 mg Fel d I and run for 15 minutes in a laboratory room (volume approximately 18 m3). Leakage was expressed as the airborne concentration of allergen in nanograms per cubic meter. RESULTS: Cleaners incorporating a double-thickness dust bag either did not leak, that is, less than 0.4 ng Fel d I/m3 or had minor leakage approximately 5 ng/m3. Vacuum cleaners with single-thickness paper bags leaked more, that is, 15 to > 90 ng/m3 with the exception of the cleaner with an efficient outer bag. Detailed studies on a vacuum cleaner that leaked showed that placing dust in the bag, replacing the dust bag with a double-thickness bag, and placing an electrostatic filter over the exhaust reduced levels from greater than 90 ng/m3 to less than 2 ng/m3. Two water-filter vacuum cleaners each emitted cat allergen (up to > 100 ng/m3) with a mean of approximately 90% on particles less than 2.5 microns diameter. This emission could be almost completely controlled by taping electrostatic filter paper over the air outlet. CONCLUSIONS: In houses with cats, different models of vacuum cleaners could either reduce or increase total airborne allergen, and could also selectively increase certain particle sizes. These results suggest that cat allergen is a good model for studying the effectiveness of vacuum cleaners recommended to allergic patients.

Air Pollution, Indoor↗

Cat allergy.

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Allergens↗

Specific allergens evoking immune reactions in the lung: relationship to asthma.

Over the last 20 yrs our understanding of the relationship of allergens to asthma has changed completely. This is due to several interrelated developments: firstly, it is clear that bronchial hyperreactivity can be increased by allergen exposure and that it is at least in part reversible; secondly, it is now generally accepted that asthma involves inflammation of the bronchi in which eosinophils play an important role; thirdly, there are a large number of studies demonstrating an epidemiological relationship between immediate hypersensitivity to dust mites and asthma; finally, it has been shown that natural exposure to dust mite allergens is very different from bronchial provocation. Together these findings have lead to the view that indoor allergens can play a major role in causing bronchial inflammation with consequent bronchial reactivity and that this is usually not apparent to the patient. Recently three studies in the USA have established that immunoglobulin E (IgE) antibodies to common inhalants can also be important risk factors for acute asthma. In these studies both dust mites and pollens were significant, but cat and cockroach allergy were also important. The results imply that the management of all asthma requires evaluation of the role of immediate hypersensitivity and that treatment of inflammation in the lungs should include both anti-inflammatory drugs and allergen avoidance.

Allergens↗

Occupational asthma and specific IgE to a diazonium salt intermediate used in the polymer industry.

This study describes sensitization to a diazonium salt intermediate, diazonium tetrafluoroborate (DTFB), produced during the manufacture of a fluorine polymer precursor. Most of the workers exposed to DTFB powder complained of respiratory and mucosal irritation. However, some of these individuals had symptoms typical of occupational asthma. Clinical and immunologic studies, including bronchial provocation testing and specific IgE measurements, were performed on two individuals with asthmatic symptoms associated with exposure to DTFB. These studies confirmed a diagnosis of occupational asthma. In an investigation of 43 other exposed workers in two separate factories handling the diazonium compound, specific IgE antibodies to DTFB-human serum albumin conjugate were found in 20% of individuals. There was a good correlation between specific IgE and exposure-related respiratory symptoms, which suggests an IgE-mediated pathogenesis. DTFB-human serum albumin conjugates were characterized by electrophoretic techniques, and it was found that conjugates prepared at pH 10 elicited optimum IgE binding in RAST. In vitro cross-linking of albumin by DTFB was demonstrated but had no effect on RAST binding. Our findings on the effect of pH and polymerization on IgE binding support proposed mechanisms for in vivo conjugation and provide information on the antigenic determinants important in IgE recognition of hapten-carrier protein conjugates.

Antibody Formation↗

Prevalence of specific IgE to storage mites (A. siro, L. destructor and T. longior) in an urban population and crossreactivity with the house dust mite (D. pteronyssinus).

The role of pyroglyphid mites in house dust allergy is well established and the major allergens from the common house dust mites (Dermatophagoides species) have been characterized. There is, however, relatively little progress in the understanding of the human IgE response to non-pyroglyphid storage mites, allergenic crossreactivity with other mite species and extent of environmental exposure. We studied 196 individuals from an urban environment who were not occupationally exposed to storage mites and found a 24% prevalence of specific IgE antibody to Dermatophagoides pteronyssinus and a 14% prevalence of RAST positivity to at least one of three storage mites, Acarus siro, Lepidoglyphus destructor and Tyrophagus longior. All individuals with a positive RAST to storage mites had specific IgE to D. pteronyssinus. RAST inhibition studies with the eight sera with greater than 2% RAST binding to both families of mites showed considerable crossreactivity between D. pteronyssinus and the storage mites A. siro and T. longior and limited crossreactivity between D. pteronyssinus and L. destructor. This suggests that at least some of the response to storage mites observed by direct RAST is a consequence of crossreactivity with the more abundant D. pteronyssinus.

Animals↗

Airborne concentrations and particle size distribution of allergen derived from domestic cats (Felis domesticus). Measurements using cascade impactor, liquid impinger, and a two-site monoclonal antibody assay for Fel d I.

The recent development of a sensitive two-site monoclonal antibody immunoassay for the major cat allergen (Fel d I) has made it possible to make accurate measurements of airborne cat allergen using low volume samplers that do not disturb the room. Houses with cats had from 2 to 20 ng Fel d I/m3 air compared with less than 0.2 ng/m3 in houses without cats. Using a cascade impactor and a multistage liquid impinger, the particle size distribution of airborne Fel d I in nine houses was 75% on particle greater than or equal to 5 microns in diameter and 25% (range, 10 to 62%) on particles less than or equal to 2.5 microns. In a cat vivarium with 12 cats, the air contained 40 ng Fel d I/m3, but less than 2% was detected on particles less than or equal to 2.5 microns. The air exchange rate in the vivarium (approximately 15 changes/h) appears to be the major difference from domestic houses (less than 0.5 changes/h). Repeated studies in one house confirmed a very high proportion (approximately 60%) of Fel d I on small particles. During domestic cleaning, the levels of small particle allergen in this house approached those produced by a nebulizer for bronchial provocation, i.e., 40 ng/m3. These results show unequivocally that significant airborne Fel d I is associated with small particles, which remain airborne for long periods. These findings are strikingly different from previous results obtained with airborne dust mite allergen. The results provide an explanation for the distinctive rapid onset of asthma or rhinitis in patients allergic to cats and a basis for designing a policy to reduce airborne allergen in houses with cats.

Air Conditioning↗

A two-site monoclonal antibody ELISA for the quantification of the major Dermatophagoides spp. allergens, Der p I and Der f I.

A two-site monoclonal antibody (Mab) ELISA was developed to measure the Group I allergens from Dermatophagoides spp., Der p I from D. pteronyssinus and Der f I from D. farinae. Species-specific Mabs were used to coat microtiter plates which were then incubated with allergen or house dust extracts. Bound allergen was detected using a biotinylated Mab which recognized a common epitope on both Der p I and Der f I, followed by the addition of streptavidin-peroxidase and ABTS/H2O2 substrate. The assay had low non-specific binding (approximately 0.08 absorbance units) and had a sensitivity of 5 ng/nl for aqueous allergen extracts (equivalent to 0.1 microgram allergen/g dust). 53 dust samples were assayed using the Mab ELISA and an RIA previously described using 125I-labelled Mab. The results showed a very good quantitative correlation between the assays (r = 0.96, p less than 0.001 for Der p I; r = 0.92, P less than 0.001 for Der f I). A further 132 dust samples from a different geographical areas were also assayed by both methods and gave correlation coefficients of 0.90 (P less than 0.001) and 0.86 (P less than 0.001) for Der p I and Der f I, respectively. The Mab ELISA will be useful in epidemiological studies of allergic asthma, both in the assessment of levels of dust mite allergen present in houses and the efficacy of allergen avoidance regimes.

Allergens↗

Hidden allergic factors in the etiology of asthma.

Increasing evidence from case control surveys, population studies and allergen avoidance studies suggest inhalant allergy plays an important role in the etiology of asthma. Recent studies in hospital emergency rooms have compared the prevalence of serum IgE antibodies to common allergens (mite, cat, cockroach, rye grass and ragweed pollen) in patients admitted with acute asthma attacks and in unselected age-matched control subjects. These studies, carried out in central Virginia and northern California, showed a highly increased prevalence of IgE antibodies to inhaled allergens among asthmatic patients, and suggest that the development of allergen specific IgE antibody responses is a major risk factor for emergency room admission with asthma. Presentation at the emergency room appeared to be related to patients' exposure to specific allergens: in central Virginia, in the fall, dust mite was the predominant allergy, whereas in northern California, in May-June, most asthmatic patients (greater than 90 percent) were allergic to rye grass. New immunoassay technology, based on the use of monoclonl antibodies, has been developed to measure the quantities of "indoor" allergens (mite, cat, cockroach) in asthmatic patients' houses. It is now possible to propose tentative levels of mite allergens which should be considered both as a risk for IgE antibody sensitization (2micrograms allergen/g dust) and as a risk for acute asthma attacks (10micrograms allergen/g dust). Future management of asthma will require analysis of indoor allergens and the development of efficient allergen avoidance procedures. Further research is necessary to investigate the relationship between airborne allergen levels, particle size and the precipitation of asthma attacks and also to investigate immunologic mechanisms which may cause bronchial hyperreactivity.

Allergens↗

Clinical and immunological investigations of respiratory disease in workers using reactive dyes.

A questionnaire survey of over 400 workers handling reactive dyes showed that over 15% had work related respiratory or nasal symptoms. Forty nine employees with symptoms were referred to chest clinics for detailed assessment. It was considered that in 19 the symptoms could be attributed to an irritant response to a variety of chemicals, including hydrochloric acid vapour, sulphur dioxide, and reactive dyes. Symptoms in 24 were attributed to an allergic reaction to a specific agent; in most (21) to one or more reactive dyes. Two patterns of allergic lower respiratory symptoms were identified; an immediate response of short duration and a longer lasting response, usually of several hours, sometimes accompanied by nocturnal asthma. A radioallergosorbent test (RAST) screen containing the most commonly used reactive dyes was used to detect specific IgE. Allergic symptoms to reactive dyes were strongly associated with specific IgE (17/21 employees) and atopy (18/21). Irritant symptoms were also associated with atopy (13/19) but only weakly associated with specific IgE (7/19).

Coloring Agents↗

Specific IgE antibodies to reactive dye-albumin conjugates.

Hypersensitivity to reactive dye powders has been recognised for a number of years, although the extent of sensitisation amongst dye house operatives and the immunochemistry of the dye molecules has not been investigated. We have developed a radioallergosorbent test (RAST) to detect specific IgE to reactive dye-human serum albumin (HSA) conjugates. From a total of 19 dye-HSA conjugates, positive RASTs were found in six workers with allergic symptoms associated with dye exposure, while six asymptomatic case-matched controls were negative. Sera with raised total IgE (up to 4300 kU/l) from unexposed workers gave negative results except for two conjugates which gave a weak positive at 4300 kU/l and one which gave weak positives at all concentrations tested (750-4300 kU/l). RAST demonstrated that the antibody was specific for the complete dye-HSA conjugate. Substitution of bovine serum albumin (BSA) for HSA in the conjugate markedly reduced immunoreactivity and free hapten gave lower inhibition than the complete conjugate. Comparison of the dye-HSA RAST with a RAST using dyed discs showed that the latter did not correlate well with symptoms and was influenced by the total IgE concentration.

Coloring Agents↗

Specificity of the human IgE response to inhaled acid anhydrides.

Patients with work-related respiratory symptoms caused by inhaled acid anhydrides (trimellitic (TMA), phthalic (PA), tetrachlorophthalic (TCPA), and maleic anhydrides) have specific IgE antibody. The antibody is specific for a conjugate of the sensitizing anhydride (the hapten) and human serum albumin (HSA). We have investigated the specificity of the reaction to determine whether the antibody is directed against (1) the anhydride, (2) new antigenic determinants formed by conjugation of albumin with the anhydride, or (3) the complete anhydride-HSA conjugate. For the patients sensitized to TCPA and TMA, RAST inhibition studies demonstrate the anhydride-HSA conjugate to be a more effective inhibitor of RAST than the sodium salt of the anhydride or an anhydride-bovine serum albumin conjugate, whereas for those sensitized to PA, the free hapten is almost as an effective inhibitor as the conjugate. With each sera HSA conjugates of anhydrides to which the patient is not sensitized are weaker inhibitors than the sensitizing anhydride-albumin conjugate. These results provide strong evidence that for the patients sensitized to TCPA and TMA, the antibody combines with the anhydride and the spatially adjacent portion of the HSA molecule, whereas in the patients sensitized to PA, the antibody is specific for the hapten.

Albumins↗