Biomedical subjects

H Ghezzo

Publications and source records attributed to H Ghezzo.

At least 19 recordsLinked to original sources

PubMed1992

Salmeterol, a new inhaled beta 2-adrenergic agonist, has a longer blocking effect than albuterol on hyperventilation-induced bronchoconstriction.

The duration of the blocking effect of salmeterol (50 micrograms), albuterol (200 micrograms), and a placebo were compared in a double-blind study in 12 adult subjects with asthma who underwent hyperventilation tests with cold dry air (-20 degrees C) on 4 study days. On the first day, the hyperventilation test was performed at various time intervals (baseline, 1, 4, 6, 8, 12, and 24 hours) with spontaneous functional recovery between each test to determine the within-day within-subject variability of the response. The response was assessed by interpolating the dose of cold dry air causing a 20% fall in FEV1. On the 3 remaining days, separated by an interval of at least 5 days, the active or placebo medication was administered after spontaneous recovery from the first hyperventilation test. Spirometry was assessed 15 minutes and 1 hour later. The hyperventilation test was then performed and repeated 4 hours after administration of the drug. The test was repeated 6, 8, 12, and 24 hours later to detect any significant blocking effect. The improvement in FEV1 15 minutes and 1 hour after the drug was administered was 19.8% and 20.4%, as compared to baseline for albuterol, and 16.3% and 16.8% for salmeterol (not significant). The mean duration of the blocking effect was 0.25 hour for the placebo, 3.5 hours for albuterol, and 15.9 hours for salmeterol (F = 24.5; p less than 0.001; Newman-Keul's test was significant for every contrast). Eight of the 12 subjects still demonstrated some blocking effect 8 hours after taking salmeterol; this was true for only one subject receiving albuterol.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

Natural history of occupational asthma: relevance of type of agent and other factors in the rate of development of symptoms in affected subjects.

It is unknown whether factors such as the nature of the agent, gender, age, atopy, smoking habits, continuous or noncontinuous exposure, and pattern of asthmatic reaction can influence the rate of development of symptoms in subjects with occupational asthma. We compared several clinical and functional parameters among three groups of subjects with occupational asthma caused by Western red cedar (group 1, n = 433), isocyanates (group 2, n = 107), and high molecular weight agents acting through an IgE-mediated mechanism (group 3, n = 121). Survival analysis showed that the three curves relating years of exposure before onset of symptoms to the proportion of subjects without symptoms were significantly different in two respects: (1) almost 40% of subjects in groups 1 and 2 as compared with 20% of subjects in group 3 became symptomatic within 1 year of exposure; (2) after 5 years of exposure, the rate of sensitization was slower for subjects in groups 2 and 3 as compared with those in group 1. Having a nonimmediate reaction at the time of specific inhalation challenges, being continuously exposed and being younger slightly increased the risk at each time point on the curve of developing symptoms in subjects with occupational asthma. These data suggest that the natural history for onset of occupational asthma is different depending on the sensitizing agent. Factors such as age, type of exposure, and pattern of reaction on exposure to the agent also modulate the rate of development of this condition.

Adult↗

PubMed1992

Morphometric changes during the early airway response to allergen challenge in the rat.

The purpose of this study was to determine the relative contributions of airway wall edema and smooth muscle contraction to the early response (ER) of allergic bronchoconstriction. Brown Norway rats, 6 to 7 wk old, were sensitized with ovalbumin (OA). Anesthetized rats were challenged with either OA or saline 2 wk later. Pulmonary resistance (RL) was measured every minute until either it increased to 150% of the baseline, defined as a significant ER, or until 15 min elapsed. Eight OA-challenged test rats with a significant ER and eight saline-challenged control rats were used for morphometric studies. The lungs were quick-frozen with liquid nitrogen, processed with freeze substitution, and sagittal sections (5 microns) were stained with hematoxylin and eosin. The airway lumen subtended by the epithelial basement membrane (LuB) and cross sectional airway wall area (AW) of all airways were measured by camera lucida and digitization. The LuB and AW of each airway was standardized for size by dividing by the ideal airway lumen (LuBideal), which was calculated from the length of basement membrane, assuming a perfect circle in the unconstricted state. The cumulative frequency distribution of the LuB/LuBideal for the airways from test rats was shifted to the left compared with the control rats (p less than 0.01), indicating airway narrowing after challenge. Airway narrowing increased as a function of airway size. Cumulative frequency distributions of AW/LuBideal showed that there was a significant increase in the wall thickness of only the small airways of test animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Allergens↗

PubMed1992

Single-dose effect of astemizole on bronchoconstriction induced by histamine in asthmatic subjects.

STUDY OBJECTIVE: Astemizole, administered for seven days to asthmatic subjects, had an effect of bronchoconstriction induced by inhaled histamine for a mean period of 42 days. This study evaluates whether a single dose of astemizole would have the same effect. SUBJECTS: Sixteen adult asthmatic subjects took part in the study. DESIGN: They first underwent three inhalation tests and skin prick tests with histamine on three different days. On the last day, a methacholine inhalation test was also performed. They subsequently received either a placebo or an active preparation of astemizole. The histamine inhalation test was repeated one day, two days, one week, and/or ten days after administering the drug. RESULTS: Overall, no significant change in mean PC20 or in the mean diameter of the skin reaction to histamine was observed. However, three out of the eight subjects (38 percent) receiving active and none receiving placebo medication showed significant increases in PC20 histamine (p = 0.05). This effect lasted for one to two days. CONCLUSIONS: We conclude that a single dose of 10 mg/ml of astemizole can have a significant effect on bronchial but not cutaneous reactivity to histamine. This effect is of short duration (one to two days).

Adult↗

PubMed1992

[Duration of bronchial protective effect of salmeterol in asthma induced by hyperventilation with dry cold air].

The duration of the blocking effect of salmeterol (50 micrograms), albuterol (200 micrograms) and placebo was compared in a double-blind study carried out in 12 adult asthmatic subjects who underwent hyperventilation tests with cold dry air on 4 study days. On the first day, the hyperventilation test was carried out at various time intervals with spontaneous functional recovery between each test. The response was assessed by interpolating the dose of cold dry air causing a 20% fall in FEV1 (PD20). On the three other days, the active or placebo medications were administered. Spirometry was assessed 15 minutes and 1 hour later. The hyperventilation test was then performed and repeated at various time intervals after administering the drug. The mean duration of the blocking effect was 0.25 hour for placebo, 3.5 hours for albuterol, and of 15.9 hours for salmeterol. Eight of the 12 subjects still showed some blocking effect eight hours after salmeterol by comparison with only one subject after albuterol. The authors conclude that salmeterol has a significantly longer effect than albuterol on bronchoconstriction induced by hyperventilation.

Adrenergic beta-Agonists↗

PubMed1991

Reassessment of the temporal patterns of bronchial obstruction after exposure to occupational sensitizing agents.

Typical asthmatic reactions after exposure to common or occupational allergens have been classified as isolated immediate, early late, late, and dual (Pepys and Hutchcroft, 1975). Atypical reactions can also occur, but their temporal behavior and frequency are unknown. We analyzed 69 bronchospastic reactions after exposure to three types of occupational sensitizers in the laboratory: isocyanates, western red cedar, and IgE sensitizing agents. Graphs of the reactions were presented to three observers in a blind, randomized way. Reactions were defined as follows: (1) typical patterns, that is, isolated immediate, early late, late, and dual, as put forward by Pepys and Hutchcroft, and (2) atypical patterns including progressive (onset, during, or minutes after exposure, progressing to a maximum reaction 5 to 6 hours later) and square waved (similar to a dual reaction but with only partial recovery [less than 10%] between the immediate and late falls in FEV1). Some curves were also analyzed by polynomial regression. The three observers agreed in 59/69 cases (86%), and a consensus was reached after discussion for the remaining subjects. Fifteen of 63 (22%) reactions were atypical. IgE-mediated reactions and reactions to red cedar were, respectively, mainly of the immediate and late types. The distribution of reactions to isocyanates, however, was significantly different (chi-square, 6.1; p = 0.01), the "progressive" pattern occurring in 7/23 instances (30%). There was a satisfactory concordance between visual assessment and polynomial fit analysis in distinguishing dual from square-waved reactions. We conclude that isocyanates frequently cause atypical progressive bronchospastic reactions that are rarely observed after exposure to IgE agents and western red cedar.

Adult↗

PubMed1991

Is the clinical history a satisfactory means of diagnosing occupational asthma?

In some countries a diagnosis of occupational asthma for medicolegal purposes is made when a questionnaire is suggestive and the individual is exposed to a product known to be a sensitizer. The value of an open questionnaire administered by physicians with experience in occupational asthma is unknown, however. We prospectively assessed all subjects (162) referred to our clinic because their physicians thought their asthma might be work related. The medical questionnaire included questions about the nature of the symptoms (dyspnea, wheezing, cough, and chest tightness) and the timing (worse at work or after a shift at work or improved during weekends or holidays). An initial clinical assessment was set by the physician on a scale that ranged from highly probable to probable, uncertain, unlikely, or absent. Subjects then underwent objective assessment with specific inhalation challenges (n = 72), serial monitoring of peak expiratory flow rates for periods at work and away from work (n = 29), or both (n = 61), to confirm or rule out the diagnosis of occupational asthma. A total of 75 subjects (46%) were shown to have occupational asthma. Symptoms alone (type and timing) did not provide a satisfactory differentiation between those subjects with and those without occupational asthma. For example, 66 of 75 (88%) subjects with occupational asthma said that their symptoms improved during holidays, but 66 of 87 (76%) subjects without occupational asthma experienced a similar improvement.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

The destructive index and early lung destruction in smokers.

The destructive index (DI), a measure of alveolar septal damage and emphysema, has been proposed as a sensitive index of lung destruction that closely reflects functional abnormalities, especially loss of elastic recoil. To better understand the progression of lung destruction in smokers, we studied the contribution of its principal components: breaks in the alveolar septa (DIb) and the presence of emphysematous spaces (DIe), and compared them to the mean linear intercept (Lm) and DI as originally described. To do this we employed lungs obtained at autopsy from non-smokers and smokers. Lungs were selected by emphysema score (ES) so that all cases were emphysema free (nonsmokers and seven smokers) or had minimal emphysema (nine smokers; ES = 5). Of these indices, only DIb was significantly increased in the lungs of smokers: 17.8 +/- 1.2 versus 12.4 +/- 1.6, p less than 0.05. We also investigated the regional distribution of destruction by comparing results in upper and lower lobes. DIe, but not DIb, was significantly increased in upper lobes of smokers. These data support the notion that increases in DI in the lungs of smokers that occur before increases in Lm or ES reflect the presence of alveolar septal breaks and highlight the importance of alveolar septal destruction as a precursor to the development of airspace enlargement in the lungs of cigarette smokers.

Adult↗

PubMed1991

Centrilobular and panlobular emphysema in smokers. Two distinct morphologic and functional entities.

In order to investigate the hypothesis that different morphologic patterns of disease might correspond to different mechanical properties of the lung in emphysema, pulmonary function tests and lung mechanics were measured in 34 subjects undergoing lung resection for peripheral lung tumors. Using standard microscopic criteria, pure or predominant centrilobular (n = 18) or panlobular (n = 16) emphysema was diagnosed in lungs. The degree of emphysema measured by the mean linear intercept (Lm) was not significantly different between the two groups. However, the coefficient of variation of the interalveolar wall distance (CV) was significantly higher for the same Lm in CLE than in PLE. This indicates that CLE has an uneven pattern of destruction, whereas PLE is more homogeneous. CLE had a higher degree of abnormalities in the small airways (SAD) than did PLE (p less than 0.05) mainly because of significantly higher muscle score (p less than 0.001) and fibrosis. CLE also had a higher proportion of airways less than 400 microns in diameter than did PLE (p less than 0.05). Static compliance, specific compliance, and the exponential constant (K) were significantly lower (p less than 0.005, p less than 0.001, and p less than 0.05, respectively) in CLE than in PLE. FEV1/FVC was significantly correlated with SAD in CLE (r = -0.69, p less than 0.01) but not in PLE (r = 0.29 p greater than 0.05); conversely, FEV1/FVC was significantly correlated with elasticity (K) in PLE (r = -0.72, p less than 0.01) but not in CLE (r = 0.08, p greater than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

PubMed1991

Comparison of peak expiratory flow rate and FEV1 in assessing bronchomotor tone after challenges with occupational sensitizers.

Bronchial responses to occupational sensitizers measured by peak expiratory flow rate (PEFR) and forced expiratory volume in 1 s (FEV1) during late reactions (between 90 minutes and 8 hours after exposure) were compared in two groups of 88 subjects who had undergone specific inhalation challenges in the laboratory. The first group had what was considered a positive reaction (a fall of at least 15 percent in FEV1) whereas the second group's reaction was interpreted as negative (fall in FEV1 less than 15 percent). Although the correlation in terms of percentage of change from baseline values was statistically significant, the correspondence was poor. PEFR proved far less sensitive than FEV1 in detecting a reaction. Whereas the mean maximum change in FEV1 overall was 27 percent, the mean maximum change in PEFR at the same time interval was only 16 percent. Moreover, individual correlations between the percentage of change in FEV1 and PEFR were satisfactory (r2 greater than 0.80) in only 32/88 subjects (36 percent). No subject who was considered to have a negative challenge according to FEV1 had a change in PEFR greater than 20 percent. We therefore conclude that changes in PEFR are far less sensitive than changes in FEV1 in detecting responses during late reactions to occupational sensitizers.

Adult↗

PubMed1990

Late asthmatic reactions to occupational sensitizing agents: frequency of changes in nonspecific bronchial responsiveness and of response to inhaled beta 2-adrenergic agent.

Late asthmatic reactions have been demonstrated, generally, to increase bronchial responsiveness and are believed to respond poorly to inhaled bronchodilator. To assess the frequency of changes in bronchial responsiveness, we reviewed the records of 101 subjects with late asthmatic reactions and of 63 subjects with isolated immediate reactions after specific inhalation challenges to various occupational agents. These subjects had undergone nonspecific inhalation challenges to histamine or methacholine on a control day and after the late reaction when FEV1 had returned to +/- 10% baseline. We also reviewed 99 cases of subjects with late reactions who were administered an inhaled beta 2-agent (albuterol, 200 micrograms) during the late reaction. Fifty-seven/101 (56%) subjects with late reactions and 24/63 (38%) subjects with isolated immediate reactions demonstrated a twofold or greater change in provocative concentration of histamine or methacholine causing a 20% change in FEV1 (PC20) from baseline (p = 0.02; odds for the presence of significant changes in PC20 in subjects with late reactions, 56%; odds for the absence of significant changes in PC20 in subjects with immediate reactions, 62%). Changes in FEV1 greater than 20% after administering albuterol at the time of the late reactions occurred in 78% of the subjects tested; in 66%, FEV1 returned to greater than 90% baseline. This retrospective study demonstrates that changes in bronchial responsiveness after late reactions are not constant and do not appear to distinguish satisfactorily late from immediate reactions. Furthermore, late reactions respond well to beta 2-agonist.(ABSTRACT TRUNCATED AT 250 WORDS)

Albuterol↗

PubMed1990

Duration of the effect of astemizole on histamine-inhalation tests.

The aim of the study was to investigate if astemizole, a new, long-acting antihistamine preparation, has an effect on histamine-inhalation tests and to assess the duration of action of this medication. The study included a group of 15 adult subjects with asthma in a clinically stable state. The subjects all demonstrated mild to severe bronchial hyperresponsiveness (geometric mean provocative concentration causing a 20% fall in FEV1 (PC20) histamine, 0.57; range, 0.20 to 4.7 mg/ml). The first part of the study was a double-blind, 7-day trial of astemizole (10 mg/day) or placebo, assigned in random order for the first eight subjects. The seven subjects entering the trial subsequently were administered active medication only. PC20 histamine was assessed on the 3 consecutive days before starting the trial, on the last day of medication, 3 days later, and once a week thereafter until PC20 returned to baseline. PC20 methacholine was also assessed before the trial and regularly thereafter to ensure functional stability. No significant changes in PC20 histamine were documented in the placebo-treated group, but the four subjects receiving active medication demonstrated marked changes in PC20 histamine (from a tenfold to a greater than 100-fold difference) (p = 0.001). There were no significant differences in changes in PC20 methacholine between the two treatment groups (p = 0.27). The duration of recovery of bronchial response to histamine in all 15 subjects ranged from 12 to 102 days (mean, 42 days) and was in some subjects, longer than the duration of the blocking effect of histamine reactivity found with skin testing.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗

PubMed1990

Prevalence of occupational asthma and immunologic sensitization to guar gum among employees at a carpet-manufacturing plant.

Guar gum is a high-molecular-weight agent that can cause occupational rhinitis and asthma. We surveyed the employees at a carpet-manufacturing plant in which guar gum is used to adhere the dye to the fiber; 162/177 of the employees (92%) participated in the first part of the survey that included a questionnaire and skin prick tests with common allergens and guar gum (1 mg/ml). IgE and IgG antibodies to guar gum were also measured in those subjects (133/162 or 82%) who agreed to blood tests. Thirty-seven subjects (23%) had a history suggestive of occupational asthma and 59 (36%), of occupational rhinitis. Eight subjects (5%) demonstrated immediate skin reactivity to guar gum. Eleven subjects (8.3%) had serum IgE antibodies to guar gum. All subjects, except one subject who had a history suggestive of occupational asthma (n = 37) or positive skin tests (n = 4), participated in the second part of the study. A methacholine-inhalation test was performed during a workshift or in the 3 to 4 hours after the workshift. Five subjects had a concentration of methacholine causing a 20% fall in FEV1 of less than 16 mg/ml (significant bronchial hyperresponsiveness) and positive skin reactions to guar gum. Four of these subjects underwent specific inhalation challenges. The remaining subject had a history of severe bronchospastic reaction on exposure to guar gum, and his FEV1 of 1.6 L made specific challenges impossible. Two subjects had typical isolated immediate reactions.(ABSTRACT TRUNCATED AT 250 WORDS)

Asthma↗

PubMed1990

Exponential fitting of pressure-volume curves: confidence limits and sensitivity to noise.

It has recently become common to model the static pressure-volume curve of the lung as a monoexponential function of the form V = A - Be-KP, where V is volume and P is transpulmonary pressure. The parameters A, B, and particularly K have been employed as descriptors of the intrinsic mechanical properties of the lung. The purpose of the present study was to investigate the sensitivities of A, B, and K to noise in measurements of P and V and to incompleteness of data. Using Monte-Carlo simulation, we found that the presence of typical levels of noise in P led to biased estimates of K and that the 95% confidence intervals about A and K were large compared with the parameter values themselves. These effects were increased as points were systematically removed from either end of the data set. These findings show that values of K estimated from PV data are difficult to interpret without accompanying confidence intervals.

Air Pressure↗

PubMed1990

Cellularity of the alveolar walls in smokers and its relation to alveolar destruction. Functional implications.

Inflammatory cells are believed to play an important role in the pathogenesis of emphysema; however, a relationship between presence of cells in the lung parenchyma and its destruction has never been shown. The aim of this study was to quantitate alveolar septal cellularity in smokers' lungs and to investigate its relationship with parenchymal destruction and lung function. The lungs of 23 smokers (SS) undergoing thoracotomy for localized pulmonary lesions were compared with those of eight nonsmokers (NS) and five smokers (AS) who died suddenly of nonrespiratory causes. Pulmonary function tests were performed within 1 wk of surgery in SS. For each subject, we quantitated alveolar wall cells (CELLS), an index of alveolar wall destruction (DI), and the mean linear intercept (Lm). As no significant differences were found between S and AS with regard to these indices, we combined them (Group S) for comparison with NS. Although Lm was not significantly different between S and NS, (0.331 +/- 0.072 versus 0.288 +/- 0.038), CELLS and DI were higher in S than in NS (48 +/- 8 versus 25 +/- 2 cells/mm, p less than 0.001; 47 +/- 20 versus 17 +/- 5, p less than 0.001, respectively). Further, CELLS and DI were significantly correlated (r = 0.799, p less than 0.001). The number of polymorphonuclear cells (PMN) in S can exceed that in NS by as much as 5-fold; however, PMN were inversely correlated with parenchymal destruction (DI) (r = 0.598, p less than 0.01). Thus, smokers' lungs have alveolar septal hypercellularity, possibly inflammatory, and closely related to destruction involving cells other than the PMN.

Aged↗

PubMed1990

Formoterol, a new inhaled beta-2 adrenergic agonist, has a longer blocking effect than albuterol on hyperventilation-induced bronchoconstriction.

The duration of effect of inhaled formoterol (24 micrograms) was compared with that of a placebo and that of inhaled albuterol (200 micrograms) in 12 adult asthmatic subjects who underwent hyperventilation tests with cold dry air (-20 degrees C) on 4 study days. On the control day, they were subjected to four hyperventilation tests to ensure functional stability. On the 3 remaining days, after a first hyperventilation test, they inhaled placebo, albuterol, or formoterol in randomized, double-blind fashion. The hyperventilation test was repeated 1, 4, and 8 h and, if the blocking effect was still present, 12 and 24 h after the drug had been administered. The dose of hyperventilation of cold air causing a 20% fall in FEV1 (PD20) was interpolated on the dose-response curve. The magnitude of the blocking effect at each time interval on each study day was assessed by comparing the changes in PD20 from baseline with the within-day variability of PD20 (standardized change in PD20). The acute bronchodilator effect was not significantly different as assessed 15 min (21 +/- 14% for albuterol and 18 +/- 18% for formoterol) and 1 h (20 +/- 13% for albuterol and 18 +/- 17% for formoterol) after administering the medication. The duration of the blocking effect, defined as the return to 2 SD from the standardized change in PD20, was significantly more prolonged for formoterol (8.0 +/- 3.4 h) than for albuterol (3.0 +/- 1.7 h) (t = 4.2, p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗

PubMed1990

Prevalence of occupational asthma and immunologic sensitization to psyllium among health personnel in chronic care hospitals.

Psyllium is a high molecular weight laxative that can cause occupational asthma among health care workers who prepare this product for chronically ill patients. The prevalence of immunologic sensitization and occupational asthma to psyllium is unknown. We investigated the personnel of four chronic care hospitals, including two where four cases of occupational asthma had been confirmed the year preceding the trial. A questionnaire and skin prick tests with psyllium and various inhalants were administered to 193 of 248 (78%) of the workers who agreed to participate. Seventy-five subjects (39%) had a history of respiratory symptoms in normal life and/or respiratory symptoms and/or rhinoconjunctivitis after handling psyllium. Six (3%) showed skin reactivity to psyllium. Increased specific IgE antibodies were found in 20 of 162 of the sera that were tested (12%). In the second part of the study, a histamine inhalation challenge was performed on 70 of 75 (93%) of the subjects with a history suggestive of asthma and/or occupational asthma and/or skin reactivity to psyllium. Twenty (29%) had significant bronchial hyperresponsiveness. The six subjects with a history suggestive of occupational asthma (n = 3) and/or asthma (n = 6) and/or positive skin test results to psyllium (n = 6) had significant bronchial hyperresponsiveness and increased specific IgE levels. They all underwent specific inhalation challenges with psyllium in the laboratory. Four developed bronchospastic reactions (two immediate and two dual reactions). We conclude that by including the initial four cases reported in the year preceding the initiation of this trial, the prevalence of IgE sensitization to psyllium was between 5 (skin testing) and 12% (increased specific IgE levels).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Specific serum antibodies against isocyanates: association with occupational asthma.

Although increased levels of specific IgE and/or IgG antibodies have been documented in individual cases of occupational asthma caused by common types of isocyanates (hexamethylene diisocyanate [HDI] and diphenylmethane diisocyanate [MDI]), the frequency among workers with occupational asthma is still unknown. The sera of 62/65 workers referred for specific inhalation challenges with isocyanates were analyzed for the presence of specific antibodies to the relevant isocyanate. Most workers (39, 63%) were exposed to HDI, some to MDI (17, 27%), and a few to toluene diisocyanate (six, 10%). Specific inhalation challenges were positive in 29 subjects, eliciting either immediate (seven), early late (two), late (13), or dual (seven) reactions. Specific inhalation challenges were more often positive in those subjects with increased nonspecific bronchial responsiveness. Twenty-nine subjects demonstrated increased levels of specific IgE and/or IgG antibodies to isocyanates in the absence of antibodies against human serum albumin (increased IgE only, no subject; IgG only, 20; both IgE and IgG, nine subjects). Although there was a loose association between the results of specific inhalation challenges and levels of specific IgE, the association was much better with the level of specific IgG. Indeed, 21 of the 29 subjects (72%) with positive challenges had increased levels of specific IgG, whereas 25 of the 33 subjects (76%) with negative challenges had normal levels of antibodies. The association was significant with both HDI and MDI. The levels of antibodies were not significantly associated with the type of temporal reaction.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies↗