Normal C1 inhibitor mRNA expression level in type I hereditary angioedema patients: newly found C1 inhibitor gene mutations

BACKGROUND

C1 esterase inhibitor (C1INH) plays a key role in the classical pathway of the complement cascade. Mutations in this gene cause a decreased level of antigenic (type I hereditary angioedema, HAE) or functional (type II HAE) C1INH.

OBJECTIVE

To find novel mutations in C1INH and evaluate the expression of C1INH gene in HAE patients.

METHODS

Direct sequencing mutation analysis was performed for genomic DNA from three unrelated families (14 HAE patients and 18 family members). Genomic DNA from one family was also analyzed for larger genomic rearrangements, using Southern blotting analysis. We used real-time quantitative polymerase chain reaction (PCR) to evaluate C1INH mRNA expression level.

RESULTS

Four mutations in exons (2,311 T-->C, 14,034 G-->A, 16,830 G-->A, and 16,979-16,980 G insertion) and four in introns (738 G-->A, 8,531 A-->G, 14,254 A-->G, and 14,337-14,378 TT deletion) were found. Interestingly, all of the nine patients in one family share the same mutation of Gly345Arg (14,034 G-->A) in the seventh exon. In another family, a single base mutation near the splice site (14,254 A-->G) was found in all of the three patients. In the last family, although a significant mutation was not found by direct sequencing, patients showed an abnormal 16 kb fragment in addition to the normal allele (21 kb Bcl I fragment). The C1INH mRNA expression of HAE patients in two families was not significantly different compared with that of normal controls.

CONCLUSION

The two novel exonal mutations (G-->A and A-->G) and one large gene deletion were associated with the clinical phenotypes of HAE. Considering the normal C1INH mRNA levels but below normal protein levels in two families, their phenotypes would be associated with the post-translational defect.

High prevalence of current asthma and active smoking effect among the elderly

BACKGROUND

Although asthma is a common cause of morbidity in adults, relatively few objectively measured population studies of asthma prevalence in adult populations have been conducted.

OBJECTIVE

To evaluate the prevalence of asthma, based on both a questionnaire and methacholine bronchial provocation test, and to determine the risk factors of asthma prevalence in an adult population.

METHODS

A total of 2,467 adults, who were randomly selected from metropolitan urban, non-metropolitan urban and rural areas, responded to the modified ISAAC questionnaire, and underwent methacholine bronchial provocation tests and skin prick tests to locally common aeroallergens.

RESULTS

The prevalence of current asthma based on the questionnaire and the methacholine challenge was 2.0% in adults younger than 40, 3.8% in 40- to 54-year-olds, 7.7% in 55- to 64-year-olds and 12.7% in those aged 65 or higher. For subjects of 55-64 years, active smoking was found to be significantly related with the prevalence of current asthma and bronchial hyper-responsiveness, although smoking was positively associated with percentage predictive value of forced expiratory volume of 1 s (FEV1).

CONCLUSION

The prevalence of current asthma is common among the elderly, and active smoking may play an important role in the development of asthma and bronchial hyper-responsiveness among the elderly.

A case of hereditary angioedema associated with idiopathic hypoparathyroidism

Hereditary angioedema is a rare autosomal dominant disease characterized by the edema of subcutaneous tissues, respiratory tract and bowel. It is caused by the deficiency of C1 esterase inhibitor. Hereditary angioedema may be associated with autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, autoimmune thyroiditis and glomerulonephritis. We report a 34-year-old male patient with hereditary angioedema who developed idiopathic hypoparathyroidism. Autoimmunity seems to be an important basis of this association and it might be caused by the immune dysfunction due to decreased level of complements; nevertheless, a casual association could not be excluded. To our knowledge, this is the first report of hereditary angioedema in association with idiopathic hypoparathyroidism in the medical literature.

The enhanced effect of a hexameric deoxyriboguanosine run conjugation to CpG oligodeoxynucleotides on protection against allergic asthma

BACKGROUND

Oligodeoxynucleotides containing a CpG motif (CpG ODNs), as potent inducers of T(H)1 immunity, are considered promising candidates for immune modulation in asthma. We have previously demonstrated that conjugation of a hexameric deoxyriboguanosine run to the 3' terminus (3' dG(6)-run) of phosphodiester (PE) CpG ODNs enhanced their immuno-stimulatory activities in vitro.

OBJECTIVE

This study aimed to evaluate the effect of a 3' dG(6)-run conjugation to PE or phosphorothioate (PS) CpG ODNs on protection against murine allergic asthma in vivo.

METHODS

Balb/c mice were sensitized to ovalbumin by intraperitoneal injection with or without CpG ODNs (PS CpG ODNs, PE CpG ODNs, and those with 3' dG(6)-run) and subsequently challenged with ovalbumin. We evaluated airway hyperresponsiveness, eosinophil proportion in bronchoalveolar lavage fluid, airway inflammation, and ovalbumin-specific antibody responses.

RESULTS

The conjugation of a 3' dG(6)-run to PE CpG ODNs enhanced the production of IFN-gamma from ovalbumin-specific T(H) cells and prevented the development of asthma in terms of airway hyperresponsiveness, airway eosinophilia, and ovalbumin-specific IgE responses; these effects were comparable to those of PS CpG ODNs. Enhanced effects of the 3' dG(6)-run were also observed in PS CpG ODNs, though they were lower than those in PE CpG ODNs.

CONCLUSION

This study suggests that conjugation of a 3' dG(6)-run to CpG ODNs might provide an effective method for immune modulation of allergic asthma.

IgE binding components in Tetranychus urticae and Panonychus ulmi-derived crude extracts and their cross-reactivity with domestic mites

BACKGROUND

Recent investigation has revealed that spider mites such as Tetranychus urticae and Panonychus ulmi are important allergens in the development of occupational asthma among apple farmers.

OBJECTIVE

To evaluate IgE binding components in T. urticae and P. ulmi-derived crude extracts and their cross-reactivity with Panonychus citri, Tyrophagus putrescentiae and Dermatophagoides pteronyssinus in apple cultivating farmers.

METHODS

Thirty-one apple farmers with positive skin responses to T. urticae or P. ulmi were randomly recruited, and specific IgE levels in their sera were measured using ELISA. Cross-reactivity was evaluated by ELISA inhibition. IgE binding components were evaluated by IgE immunoblotting.

RESULTS

A total of 11 IgE binding components in T. urticae and 10 in P. ulmi were found. Among them, the 17 kDa, 27 kDa, 33 kDa, 37 kDa, 41 kDa, 56 kDa, and 75 kDa allergens in T. urticae, and the 33 kDa, 41 kDa, and 51 kDa allergens in P. ulmi were identified as dominant allergens. T. urticae-specific IgE binding was completely inhibited by 100 microg/mL of T. urticae (99.7%), but only partially inhibited by P. citri (83.0%), P. ulmi (71.6%), T. putrescentiae (69.7%), and D. pternonyssinus (60.1%). P. ulmi-specific IgE binding was completely inhibited by additions of P. citri (92.3%) and P. ulmi (91.2%), but only partially inhibited by the addition of T. urticae (61.5%), T. putrescentiae (57.7%), and D. pteronyssinus (54.4%).

CONCLUSION

There were seven dominant allergens found in T. urticae and three in P. ulmi. T. urticae- and P. ulmi-specific IgE bindings were partially inhibited by crude extracts derived from D. pteronyssinus and T. putrescentiae.

Citrus red mite (Panonychus citri) may be an important allergen in the development of asthma among exposed children

BACKGROUND

Recent investigations have demonstrated that spider mites are important allergens in the development of asthma in fruit-cultivating farmers.

OBJECTIVE

The aim of this study was to evaluate the sensitization rate to the citrus red mite (Panonychus citri) in children living in rural areas, and to determine the allergenic cross-reactivity with other mites.

METHODS

A total of 7254 children (ages 7-15 years) living in rural areas were enrolled, and each subject was evaluated by a questionnaire and a skin prick test. Allergenic cross-reactivity was evaluated by ELISA inhibition tests.

RESULTS

The most common sensitizing allergens were house dust mites, followed by citrus red mite and cockroach. High serum-specific IgE bindings to the citrus red mite were detected in 21 of 100 randomly selected subjects. The prevalence of asthma was higher among those with positive skin responses to the citrus red mite than with negative skin responses to this mite. ELISA inhibition tests showed that IgE bindings to this mite were minimally inhibited with additions of domestic mites.

CONCLUSION

Spider mites such as the citrus red mite may be important outdoor allergens among children living in rural areas, and spider mite-derived allergens have unique allergenic determinants compared with domestic mites.

Differences in sensitization rates to outdoor aeroallergens, especially citrus red mite (Panonychus citri), between urban and rural children

BACKGROUND

A recent investigation has suggested that citrus red mite (Panonychus citri, CRM) is the most important allergen in citrus-cultivating farmers with asthma and allergic rhinitis.

OBJECTIVE

A cross-sectional survey was performed to evaluate the prevalence of asthma and chronic rhinitis symptoms and sensitization to common indoor and outdoor aeroallergens, including CRM and Japanese cedar pollen, in rural and urban Korean children.

METHODS

A total of 2,055 children (1,055 subjects living in rural areas with citrus farms and 1,000 controls in urban areas without citrus farms) were enrolled. They were evaluated by a questionnaire, and by skin prick tests with 13 common indoor and outdoor aeroallergens, including CRM and Japanese cedar pollen.

RESULTS

The prevalence of wheezing and chronic rhinitis symptoms during the last 12 months was 8.3% and 35.7% in the rural children and 10.5% and 22.4% in the control group. The most common sensitizing allergens in order of decreasing frequency were Dermatophagoides pteronyssinus (26.6%), Dermatoplagoides farinae (22.7%), CRM (14.2%), cockroach (11.3%), and Japanese cedar pollen (9.7%) among the rural children, but the sensitization rates to CRM and Japanese cedar pollen were 1.3% and 0.2% among the control children, respectively. The prevalence of wheeze during the last 12 months was not different between rural children with sensitization to CRM or Japanese cedar pollen and those without sensitization (5.4% vs 6.1%; 6.9% vs 5.9%). However, the prevalence of chronic rhinitis during the last 12 months was higher among those with sensitization to CRM or to Japanese cedar pollen than among those without sensitization (40.8% vs 34.4%; 51.5% vs 33.5%).

CONCLUSIONS

CRM is a common sensitizing allergen in rural children, and the sensitization rates to outdoor aeroallergens, especially CRM and Japanese cedar pollen, are very different between children from rural and urban areas in Korea.

IgE-mediated occupational asthma induced by herbal medicine, Banha (Pinellia ternata)

There have been few reported cases of occupational asthma induced by Pinellia ternata (Banha), and the mechanism responsible for this type of asthma is still undetermined. We report a case of Banha-induced occupational asthma with IgE-mediated mechanism. The patient had positive skin responses to Banha extract and Banha-specific bronchial challenge elicited an early asthmatic response. The serum-specific IgE binding to Banha extract was detectable and completely inhibited with the additions of 0.1 microg/mL of Banha extract on ELISA inhibition. Seven IgE binding components to Banha extract (6.5, 22, 24, 32, 34, and 48 kDa) were detected using SDS-PAGE and immunoblot analysis. In conclusion, the results of this study suggest that P. ternata (Banha)-derived allergens are able to cause IgE-mediated bronchoconstriction in exposed workers.

Outdoor air pollutants derived from industrial processes may be causally related to the development of asthma in children

BACKGROUND

There is no consistent evidence that outdoor air pollutants are involved in the development of asthma.

OBJECTIVE

The aim of this study was to determine whether outdoor air pollutants derived from industrial processes were related to the prevalence of asthma, bronchial hyperresponsiveness, and atopy in exposed children.

METHODS

A total of 7,511 children from 7 to 12 years of age were recruited in the study. Eight hundred eighty-eight of 1,009 (88%) of the subjects living around industrial factories and 5,998 of 6,502 (92%) living in a less polluted neighboring area responded to the ISAAC questionnaire. A total of 1,492 subjects 8 to 9 years old underwent skin prick tests for 11 common aeroallergens. A total of 732 of the subjects from 8 to 9 years of age underwent bronchial provocation tests with hypertonic saline (BPT-HS).

RESULTS

The prevalence of ever experiencing wheezing and wheeze during the last 12 months was 25.6%, and 18.8% among the children living in the more polluted area. This was significantly higher than for those living in the less polluted area (14.2% and 9.0%, respectively). The positive rate of BPT-HS (the provocative dose of hypertonic saline causing 20% fall of FEV, < or = 23 mL) was higher among those in the more polluted area than in children living in the less polluted area (12.2% vs 7.5%). However, the rate of atopy based on the skin tests was the same in the two groups (28.3% vs 30.6%).

CONCLUSIONS

The prevalence of asthma and bronchial hyperresponsiveness was higher among children living around the heavily industrial area compared with those living in the less polluted area, despite similar atopic sensitization.

Identification of IgE-binding components of citrus red mite in sera of patients with citrus red mite-induced asthma

BACKGROUND

Our previous investigations demonstrated that citrus red mite (CRM) antigen could cause IgE-mediated bronchoconstriction in exposed farmers working on citrus farms.

OBJECTIVE

This study was performed to confirm IgE-binding components and major allergens within the CRM antigens.

METHODS

Ten subjects who had been diagnosed as having CRM-induced asthma were enrolled. Serum-specific IgE antibodies to CRM antigens were measured by using an ELISA. To identify IgE-binding components and major allergens, SDS-PAGE, 2-dimensional PAGE, IgE-immunoblot analysis, and amino acid sequencing of major allergens were performed.

RESULTS

All the asthmatic subjects had high specific IgE antibodies to CRMs. Twelve percent SDS-PAGE analysis showed more than 10 protein bands ranging from 6 to 64 kd. SDS-PAGE and IgE-immunoblot analysis with each individual serum showed 5 IgE-binding components (11, 24, 35, 40, and 64 kd), with 2 (24 and 35 kd) of them bound in more than 50% of the study subjects. Two-dimensional PAGE and IgE-immunoblot analysis demonstrated that the major allergen at 24 kd had 2 bands with different isoelectric points of 4.75 and 5.1. Thirty-five kilodaltons had one band with an isoelectric point of 4.75. All amino acid sequencing of the 2 major allergens was performed, which was not homologous with any previously characterized allergens.

CONCLUSION

Five IgE-binding components and 2 major allergens (24 and 35 kd) were identified within the CRM antigen. The N-terminal amino acid sequence of the 2 major allergens (24 and 35 kd) was determined.

Repeated exposure to low levels of sulfur dioxide (SO2) enhances the development of ovalbumin-induced asthmatic reactions in guinea pigs

BACKGROUND

Sulfur dioxide (SO2) is one of the major air pollutants. It is known to aggravate asthma symptoms in human beings, but few studies have focused on the effects of SO2 upon the development of bronchial asthma in animal models.

OBJECTIVE

This study was undertaken to evaluate the role of SO2 upon the development of ovalbumin (OA)-induced asthmatic reactions in guinea pigs.

METHODS

Guinea pigs were divided into four groups: (1) OA- and SO2-exposed group (n = 12), (2) SO2-exposed group (n = 12), (3) OA-exposed group (n = 11), and (4) saline-exposed group (n = 7). Guinea pigs of the first and second groups were exposed to 0.1 ppm SO2 for 5 hours a day on 5 consecutive days. Guinea pigs in the first and third groups inhaled 0.1% OA aerosols for 45 minutes a day on days 3, 4, and 5. One week after the sensitization procedure, all the guinea pigs underwent bronchial challenge with 1.0% OA aerosols, using unrestricted whole-body plethysmography. Bronchoalveolar lavage and histopathologic examination were performed 24 hours after the bronchial challenge.

RESULTS

Increases in enhanced pause (Penh), as an index of airway obstruction, after the bronchial challenge was significantly higher in OA- and SO2-exposed group (group 1) than the other groups (P < .05, respectively). Eosinophil counts in bronchoalveolar lavage fluids were also significantly higher in group 1 than in the other groups (P < .05, respectively). Histopathologic findings of bronchial and lung tissue in the group 1 showed an infiltration of inflammatory cells, bronchiolar epithelial damage, and mucus and cell plug in the lumen, but no significant abnormalities were observed in the other groups.

CONCLUSIONS

These results indicate that repeated exposure to low levels of sulfur dioxide may enhance the development of ovalbumin-induced asthmatic reactions in guinea pigs.

HLA-DRB1*07 may have a susceptibility and DRB1*04 a protective effect upon the development of a sensitization to house dust mite Dermatophagoides pteronyssinus

BACKGROUND

IgE responses to house dust mite-derived allergens seem to be the most important in the development of atopic asthma and rhinitis, but it has been difficult to demonstrate genetic control of the IgE response to the allergens.

OBJECTIVE

This study was undertaken to investigate the association between sensitization to house dust mite, D. pteronyssinus (DP), and genotypes of HLA-DRB1 alleles.

METHODS

DNAs were extracted from two groups of unrelated Koreans: (1) 178 with sensitization to DP; and (2) 99 age-matched non-atopic controls. Genotypes of the HLA-DRB1 alleles were determined using polymerase chain reaction (PCR)-based methods.

RESULTS

The frequency of HLA-DRB1*07 was significantly increased in the DP-sensitive subjects compared with the controls (15.7% vs 4.0%, P = 0.009). Conversely, the frequencies of HLA-DRB1*04 and *14 were decreased in the DP-sensitive subjects compared with the controls (27.5% vs 45.5%, P = 0.002; 13.5% vs 24.2%, P = 0.02). Of the DRB1*04 alleles, DRB1*0403 was significantly decreased in the DP-sensitive subjects compared with the controls (3.9% vs 13.1%, P = 0.005). No significant differences were found in the distributions of the other HLA-DRB1 alleles between the two groups.

CONCLUSION

HLA-DRB1*07 may have a susceptibility, and DRB1*04 and DRB1*14 may have a protective effect, upon the development of a sensitization to DP.

Linkage between bronchial responsiveness to methacholine and gene markers of IL-4 cytokine gene cluster and T-cell receptor alpha/delta gene complex in Korean nuclear families

BACKGROUND

Several candidate genes have been reported to be linked to intermediate phenotypes of asthma in Caucasian populations.

OBJECTIVE

To evaluate linkage between phenotypes of asthma and gene markers of high affinity IgE receptor-beta gene (D11S97), IL-4 cytokine gene cluster (IL-4R1), and T-cell receptor alpha/delta gene complex (D14S50) in Korean nuclear families.

METHODS

Nuclear families (127 probands and their 130 siblings) for the linkage analysis were ascertained through asthmatic children. Linkages between total serum IgE response, skin responses to common aeroallergens, and bronchial responsiveness to methacholine were performed using a sib-pair approach.

RESULTS

The square difference of the slope of the dose-response curve (DRS) between sib-pairs with two IL-4R1 identical alleles was smaller than with one or with neither IL-4R1 identical allele (P = 0.004). As for D14S50, the differences of DRS between sib-pairs with two identical alleles and with one identical allele were smaller than with neither identical alleles (P = 0.01). As for D11S97, no significant differences were observed among the groups with identical alleles of two, one or zero. With regard to total serum IgE levels, no significant linkage was found between this phenotype and the above three gene markers. As for skin responses to common aeroallergens, significant evidence was obtained to establish a linkage between this phenotype and the marker IL-4R1 (P = 0.01). However, no significant linkage was found between this phenotype and the markers D11S97 and D14S50.

CONCLUSION

The expression of bronchial responsiveness to methacholine may be influenced by genetic factors in the IL-4 cytokine gene cluster and/or T-cell receptor alpha/delta gene complex, but the genetic influence of the FcepsilonRI-beta gene may be minimal in the expression of bronchial responsiveness in Korean nuclear families.

Atopic status and level of bronchial responsiveness in parents of children with acute bronchiolitis

To examine whether children with a genetic predisposition to asthma are more likely to be afflicted with bronchiolitis, we studied 122 parents of infants who were hospitalized with the diagnosis of acute bronchiolitis (index group) and 120 parents of children who had never suffered from this disease (control group). The parents underwent bronchial challenge testing with methacholine and skin prick testing with common airborne allergens, and gave blood specimens for measurement of serum total IgE. There was no difference in atopic status, as assessed by the prevalence of atopy (at least one positive response to the allergens tested) or by serum total IgE levels, between index and control parents. The prevalence of bronchial hyperresponsiveness (BHR) (concentration of methacholine causing a 20% reduction in forced expiratory volume in 1 sec [PC20] < 18 mg/mL) was higher in index parents than in control parents (17.2% vs. 7.5%, p = 0.02). Bronchial responsiveness (BR) index was significantly higher in index parents than in control parents (1.135 +/- 0.088 vs. 1.104 +/- 0.071, p < 0.01). Parents of children who were hospitalized with acute bronchiolitis showed a higher level of BR, but not atopy. This suggests that in terms of BHR, there may be a genetic predisposition to the development of bronchiolitis.

Sensitivity to citrus red mite and the development of asthma

BACKGROUND AND OBJECTIVE

The citrus red mite (Panonychus citri, CRM) is an important allergen in the development of asthma and/or rhinitis in citrus farmers and a common sensitizing allergen among exposed children. The aim of this study was to evaluate CRM-induced skin responses and serum-specific IgE, IgG4, and IgG1 responses, and their role in the development of asthmatic symptoms among exposed adolescents.

METHODS

A total of 100 adolescents between the ages of 15 and 16 years (59 males and 41 females) were randomly recruited. All of the subjects responded to the ISAAC questionnaire themselves. Skin prick tests to CRM were carried out and serum-specific IgE, IgG4, and IgG1 levels were measured using ELISA.

RESULTS

Fourteen subjects (14%) had experienced wheezing during last 12 months. The wheal size formed by CRM was larger than 3 mm in 23 subjects (23%). Serum-specific IgE levels were elevated in 21 subjects (21%), IgG4 levels were elevated in 32 subjects (32%), and IgG1 levels were elevated in five subjects (5%). The prevalence of wheezing during last 12 months was significantly higher in subjects with positive skin responses and serum-specific IgE responses induced by CRM than in those with negative skin responses and low serum IgE responses (30.4% versus 9.0%, P < .05; 33.3% versus 8.7%, P < .05). The prevalence of wheezing, however, did not differ according to serum-specific IgG4 levels (9.4% versus 16.2%, P > .05). Skin responses to CRM showed a significant correlation with serum-specific IgE levels, but not with IgG1 and IgG4 levels. Serum CRM-specific IgE levels correlated with specific IgG1 and IgG4 levels, but no significant correlation was found between serum IgG1 and IgG4 levels.

CONCLUSION

The specific IgE responses induced by CRM were prevalent among adolescents living near citrus farms, and may be important in the development of asthma. The specific IgG4 and IgG responses induced by CRM play a minimal role in the development of asthma symptoms.

Association of HLA-DRB1(*)07 and DRB1(*)04 to citrus red mite (Panonychus citri) and house dust mite sensitive asthma

BACKGROUND

Specific IgE responses to allergens provide useful models for evaluating the genetic factors that control human immune responses. A recent survey demonstrated that the citrus red mite (Panonychus citri, CRM) is the most important allergen in the development of asthma in citrus farmers.

OBJECTIVE

The aim of this study was to evaluate whether susceptibility or resistance to CRM-induced asthma was associated with HLA-DRB1 gene.

METHODS

DNAs were extracted from two groups of unrelated Korean adults living around citrus farms: (1) Ninety-one adults with CRM-sensitive asthma; and (2) 98 exposed, healthy nonatopic controls. Genotypes of HLA-DRB1 alleles were carried out using PCR-based methods.

RESULTS

Allelic frequency of HLA-DRB1(*)07 was higher in the CRM-sensitive asthmatics compared to the controls (17.6% vs 4.1%, Pc = 0.01). Conversely, the frequency of DRB1*04 was lower in the CRM-sensitive asthmatics compared to the controls (19.8% vs 40.8%, Pc = 0.01). No significant difference was found in the distributions of the other HLA-DRB1 gene-encoded antigens between the two groups.

CONCLUSION

HLA-DRB1 genes may be involved in the development of CRM-induced asthma. In addition, HLA-DR7 may increase, and DR4 decrease, the risk of developing the asthma in CRM-exposed adults.

Citrus red mite (Panonychus citri) is a common sensitizing allergen among children living around citrus orchards

BACKGROUND

A recent investigation has suggested that Panonychus citri (citrus red mite) is the most common causative allergen in citrus-cultivating farmers with asthma or allergic rhinitis.

OBJECTIVE

A cross-sectional survey was performed to evaluate the prevalence of asthma and sensitization to P. citri among children living around citrus orchards.

METHODS

A total of 1,055 children living around citrus orchards were enrolled. There were 544 boys and 511 girls with a mean age of 12.3 (range 7 to 16) years. They were evaluated by the ISAAC questionnaire, and a skin prick test with 13 common aeroallergens including P. citri and Japanese cedar pollen. Children who recorded ever having experienced wheezing on the questionnaire were evaluated by methacholine bronchial provocation test and determined to have asthma if they showed bronchial hyperresponsiveness to methacholine simultaneously.

RESULTS

The positive skin test response to one or more inhalant allergens except P. citri was 35.5%, but when including P. citri, the positive response increased to 37.7%. The most common sensitizing allergens in the order of decreasing frequency were Dermatophagoides pteronyssinus (26.6%), D. farinae (22.7%), P. citri (14.2%), cockroach (11.3%), and Japanese cedar pollen (9.7%). Among the children without sensitization to house dust mites, the sensitization rate to P. citri was significantly higher in those 13 and over than in those under 12 (5.8% versus 2.5%, P < .05). The prevalence of asthma was not different between the children with sensitization to P. citri and those without it (5.4% versus 4.0%, P > .05), although the prevalence was higher in those with sensitization to D. pteronyssinus or D. farinae than in those without sensitization to these allergens (7.9% versus 2.9%, P < .05; 9.7% versus 2.6%, P < .05).

CONCLUSION

Citrus red mite is a common sensitizing allergen among children living around citrus orchards. The features of sensitization and development of asthma are different between citrus red mite and house dust mites.

Bronchial responsiveness to methacholine is increased in citrus red mite (Panonychus citri)-sensitive children without asthmatic symptoms

BACKGROUND

A recent investigation has suggested that citrus red mite (Panonychus citri, CRM) is a common sensitizing allergen among children living around citrus farms.

OBJECTIVE

A cross-sectional survey was performed to evaluate the bronchial responsiveness to methacholine in CRM-sensitive children without asthmatic symptoms.

SUBJECTS AND METHODS

A total of 375 children living around citrus farms were enrolled in this study. There were 201 boys and 174 girls with a mean age of 12.5 (range 7-16) years. Each subject was evaluated by a questionnaire, a skin prick test with 13 common inhalant allergens including CRM, and a methacholine bronchial provocation test (MBPT).

RESULTS

Positive rate of MBPT (PC20-methacholine < 25 mg/mL) was higher in atopic rhinitic and atopic control children than in nonatopic rhinitic and nonatopic control subjects (41.3% and 33.3% vs 17.2% and 15.4%, respectively, both P < 0.05). Slope of dose-response curve (DRS, %/mg/mL) was higher in atopic rhinitic children than in nonatopic rhinitic, atopic control and nonatopic control subjects (14.3 +/- 0.87 vs 9.4 +/- 0.72, 10.0 +/- 1.37 and 9.2 +/- 1.51, P < 0.05, respectively). Both the positive rate of MBPT and the DRS were increased in children with positive skin response to CRM than in those without sensitization (48.2% vs 22.9%, P = 0.0001; 15.6 +/- 1.26 vs 10.2 +/- 0.65, P = 0.0001).

CONCLUSION

Bronchial responsiveness is increased in citrus red mite-sensitive children even if they have no asthmatic symptoms.

Two-spotted spider mite (Tetranychus urticae): an important allergen in asthmatic non-farmers symtomatic in summer and fall months

BACKGROUND

The Tetranychus urticae (two-spotted spider mite, TSM) is a spider mite commonly found on fruit trees, herbaceous plants, and greenhouse flowers.

OBJECTIVE

To evaluate the clinical significance of TSM-derived allergens in non-farmers with asthma living around pear orchards, and to assess the allergenic relationship with house dust mite.

METHODS

Skin prick tests with TSM were performed in 50 asthmatic non-farmers living around pear orchards. The serum TSM-specific IgE was measured in the 16 asthmatics with a positive skin response to TSM. To diagnose TSM-induced asthma, specific bronchial challenges with TSM were performed in the 16 asthmatics. ELISA inhibition tests were performed to assess the allergenic cross-reactivity with house dust mites.

RESULTS

Ten of the 16 asthmatics with positive skin responses to TSM showed a significant bronchoconstriction following inhalation of TSM. Eight of the ten TSM-induced asthmatics had high serum TSM-specific IgE and one showed a positive skin response only to TSM. Their asthmatic symptoms were aggravated seasonally, especially in summer and early fall. On ELISA inhibition tests, partial inhibitions with D. pteronyssinus antigens were noted in sera from five asthmatics with positive skin responses to both TSM and D. pteronyssinus, although no inhibition was noted in serum from an asthmatic with a positive skin response only to TSM.

CONCLUSION

Tetranychus urticae may be an important allergen in asthmatic non-farmers living around pear orchards and TSM extracts contain species-specific allergens as well as commonly shared allergens with house dust mite.

Spider mite allergy in apple-cultivating farmers: European red mite (Panonychus ulmi) and two-spotted spider mite (Tetranychus urticae) may be important allergens in the development of work-related asthma and rhinitis symptoms

BACKGROUND

Recent investigations have suggested that the citrus red mite (Panonychus citri) is the most important allergen affecting citrus-cultivating farmers with asthma, allergic rhinitis, or both.

OBJECTIVE

We sought to evaluate type I hypersensitivity to spider mites, particularly the European red mite (Panonychus ulmi) and the two-spotted spider mite (Tetranychus urticae), and to determine the relationship between hypersensitivity to spider mites and respiratory dysfunction.

METHODS

We performed a cross-sectional survey. Questionnaires were given, and skin prick tests for 11 inhalant allergens common in Korea and 2 species of spider mites (European red mite and two-spotted spider mite) were performed in 725 apple-cultivating farmers in Korea.

RESULTS

Results of skin prick tests in the apple farmers indicated that European red mite (23.2%) was the most common sensitizing allergen, followed by Tyrophagus putrescentiae (21.2%), two-spotted spider mite (16.6%), Dermatophagoides farinae (16.3%), D pteronyssinus (14.4%), cockroach (13.1%), and Hop Japanese (Humulus Japonicus) pollen (12.0%). Positive skin responses (mean wheal size >/=3 mm) to one or more of 13 inhalant allergens were found in 48.2% of farmers tested, whereas 40 subjects (8.6%) had an isolated skin response to the spider mites. Among 119 farmers with work-related asthmatic symptoms, the positive skin response rates to European red mite and two-spotted spider mite were 40.4% and 27.0%, respectively. These figures were significantly higher than those found among farmers without work-related symptoms (19.1% and 14.1%, respectively; P <.01). The prevalence of work-related asthma symptoms was higher in farmers with positive skin responses to spider mites than in those with negative skin responses to spider mites and those with positive skin responses to any allergen tested (31.4% vs 15.0% vs 21.0%, respectively; P <.05).

CONCLUSION

Spider mites, particularly European red mite and 2-spotted spider mite, are common sensitizing allergens in apple-cultivating farmers. These spider mites may be important causative allergens in the development of work-related respiratory symptoms in these workers.

Linkage between IgE receptor-mediated histamine releasability from basophils and gene marker of chromosome 11q13

BACKGROUND

The genetics of the regulation of the release of mediators involving the interaction of IgE with cells and their ability to release mediators have not been extensively investigated. With use of the candidate gene approach, it was reported that the gene regulating the beta chain of the high-affinity receptor for IgE is on chromosome 11q13.

OBJECTIVE

To determine whether gene(s) in chromosome 11q13 may control the expression of maximal histamine release from basophil to anti-IgE stimuli, linkage analysis between this phenotype and the gene marker of chromosome 11q13 was performed.

METHODS

Maximal histamine release to anti-IgE and calcium ionophore A23187 and genotyping chromosome 11q13 with use of microsatellite marker (D11S97) were performed in 56 probands with asthma and 59 of their siblings. The linkage was analyzed by affected sib-pair analysis and the quantitative trait locus approach.

RESULTS

Maximal histamine release (mean +/- SE) to anti-IgE and A23187 was 43.3% +/- 3.5% and 30.9 +/- 3.4% in probands and 29.5% +/- 2.6% and 22.2% +/- 2.7 in siblings, respectively. Of 20 sib-pairs with the maximal histamine release to anti-IgE more than 33% (mean plus 1 SD of nonasthmatic controls), 11 (55%) shared 2 D11S97 alleles, 9 (45%) shared 1 allele, and neither sib-pair shared identical alleles, which indicates a significant linkage of maximal histamine to anti-IgE and gene marker of chromosome 11q13 (P =.02). The difference (mean +/- SE) of the maximal histamine release to anti-IgE between each proband and sibling was smaller in sib-pairs with 2 identical alleles than in those with 1 identical allele and with no identical allele (14.1% +/- 2.6% vs 25.8% +/- 3.1% vs 41.0% +/- 4.9%). However, the difference (mean +/- SE) to A23187 between each proband and sibling was not different among the 3 groups (9.7% +/- 1.8% vs 17.9% +/- 3.6% vs 10.4% +/- 4.8%).

CONCLUSION

Maximal histamine release from basophils to anti-IgE stimuli was linked to the gene marker of chromosome 11q13.

Citrus red mite (Panonychus citri) is the most common sensitizing allergen of asthma and rhinitis in citrus farmers

OBJECTIVE

To evaluate type I hypersensitivity to citrus red mite (Panonychus citri), its prevalence, and relationship to respiratory dysfunction, a cross-sectional survey was performed among citrus farmers on Cheju Island, Korea.

MATERIALS AND METHODS

Questionnaires, and skin prick test responses to 11 common inhalant allergens and citrus red mite were performed in 181 citrus farmers, and serum-specific IgE antibodies to citrus red mite were measured by ELISA in sera of 123 subjects. To determine airway hyperresponsiveness, methacholine bronchial provocation tests were performed in 55 subjects who complained of recurrent lower respiratory symptoms.

RESULTS

The prevalence of asthma-based on presence of asthmatic symptoms on the questionnaire and airway hyperresponsiveness to methacholine, and allergic rhinitis based on presence of nasal symptoms on the questionnaire and positive skin-test response were 12.1% and 19.3%, respectively. The positive rate of skin responses to one or more of 11 common inhalant allergens excluding citrus red mite was 17.1%, and if citrus red mite was included, 25.9% of farmers had positive responses. On skin prick tests, citrus red mite (16.5%) was the most common sensitizing allergen, followed by cockroach (11.0%), Dermatophagoides pteronyssinus (9.9%), and D. farinae (9.3%). Among farmers with asthma and allergic rhinitis, the positive skin responses to citrus red mite were noted in 54.5 and 68.5%, respectively. Serum-specific IgE antibodies to citrus red mite were detected in 45 farmers (36. 5%) of the 123 tested, and there was significant correlation between specific IgE level and weal (A/H ratio) to citrus red mite (r = 0.57, P < 0.001). The prevalence of asthma was higher in subjects with positive skin responses or high serum-specific IgE antibodies to citrus red mite than in those without skin response or serum specific IgE (P < 0.05, respectively).

CONCLUSION

Citrus red mite is the most important allergen in citrus farmers with asthma and rhinitis in which causative allergen has not been identified. It should be included in the skin test battery for screening the causative allergen in farmers exposed to citrus red mite.

Skin reactivity to inhalant allergens, total serum IgE levels, and bronchial responsiveness to methacholine are increased in parents of nonatopic asthmatic children

BACKGROUND

Family studies suggest that asthma has an increased familial occurrence, but the hypothesis of a genetic predisposition to IgE response and bronchial hyperresponsiveness (BHR) on the expression of nonatopic asthma is controversial.

OBJECTIVE

The aim of this study was to evaluate familial predisposition to IgE response and BHR on expression of nonatopic asthma.

METHODS

One hundred four parents of nonatopic asthmatic children, 154 parents of atopic asthmatic children, 78 parents of atopic nonasthmatic control children, and 80 parents of nonatopic control children provided questionnaire data and underwent allergy skin prick tests with 10 inhalant allergens and methacholine bronchial provocation tests. Total serum IgE levels were determined in 352 parents (134 with atopic asthmatic children, 87 with nonatopic asthmatic children, 65 with atopic control children, and 66 with nonatopic control children).

RESULTS

Prevalence of asthma, based on questionnaire data and on BHR to methacholine, was higher among parents of nonatopic asthmatic children (10.6%) and atopic asthmatic children (9.1%) than among those of nonatopic control children (1.3%). BHR to methacholine was higher among parents of nonatopic asthmatic children (19.2%) and atopic asthmatic children (16.2%) than among those of atopic and nonatopic control children (5.1% and 1.3%, respectively). The percentage of positive skin test responses to 10 inhalant allergens was higher among parents of atopic asthmatic children (43.9%), nonatopic asthmatic children (39.4%), and atopic control children (38.5%) than among those of nonatopic control children (23.7%). Geometric means (IU/mL +/- SEM) of total serum IgE were higher among parents of atopic and nonatopic control children than among those of nonatopic control children (2.11 +/- 0.05 vs 2. 20 +/- 0.06 vs 2.09 +/- 0.07 vs 1.92 +/- 0.06).

CONCLUSION

Nonatopic asthma runs in families. The prevalence of positive skin test responses to inhalant allergens, BHR to methacholine, and total serum IgE levels is higher among the parents of nonatopic and atopic asthmatic children than among those of nonatopic control children.

Comparison of basophil histamine releasability between atopic and nonatopic asthmatics

To compare the mediator releasability between atopic and nonatopic asthmatics, we measured basophil histamine releasability (BaHR) using a calcium-ionophore A23187 and anti-IgE in 137 subjects who were treated at Seoul National University Hospital. Subjects were categorized into atopic (group AA, n=77) or nonatopic asthmatics (group NA, n=32), or normal controls (group NC, n=28). Serum total IgE levels were determined and correlation with BaHR was assessed. Anti-IgE-induced maximal BaHR in groups AA, NA, and NC was 41.0+/-3.2, 23.1+/-4.5, and 16.8+/-3.8, respectively (mean+/-SE, %). Anti-IgE-induced BaHR in group AA was significantly higher than that in groups NA and NC (p<0.05). Calcium ionophore A23187-induced maximal BaHR was 43.1+/-2.8, 40.8+/-4.4, and 50.5+/-5.2, respectively (mean+/-SE, %), and there was no significant difference among the groups. Serum total IgE level correlated significantly with anti-IgE-induced maximal BaHR (r=0.281, p<0.01) but not with that induced by calcium ionophore A23187. In conclusion, IgE receptor-related BaHR is higher in atopic asthmatics than in nonatopic asthmatics, and this increased BaHR in atopics is significantly associated with increased serum total IgE level.

New occupational allergen in citrus farmers: citrus red mite (Panonychus citri)

BACKGROUND

There have been several reports of occupational allergy to spider mites (Tetranychidae), but no published report has described citrus red mite (CRM, Panonychus citri)-induced occupational asthma confirmed by specific bronchial challenge.

OBJECTIVE

The purpose of this study was to evaluate clinical and immunologic characteristics of CRM-induced occupational asthma.

METHODS AND RESULTS

We encountered 16 cases of CRM-induced occupational asthma among farmers cultivating citrus fruits. Asthmatic attacks corresponded closely with their work on citrus farms. The mean duration of the latent period was 12.9 (range 7 to 20) years. During their first visit to our clinic, nine patients with FEV1 lower than 70% of predictive value showed reversible airway obstruction after inhalation of bronchodilator, and seven with FEV1 greater than 70% of predictive value showed airway hyperresponsiveness to methacholine. Fifteen of the 16 also complained of recurrent nasal symptoms, which had developed at an earlier time than the asthmatic symptoms. They showed strong positive reactions to CRM extract on skin prick test (A/H ratio > or = 1.0) and had high serum specific IgE antibody against CRM which was detected by ELISA. Skin prick test with common inhalant allergens revealed that 10 had an isolated positive response to CRM with negative results to common inhalant allergens in their environment. The ELISA inhibition tests with CRM demonstrated significant inhibitions by CRM in a dose-dependent manner, while minimal inhibitions were noted by D. pteronyssinus and mugwort allergens.

CONCLUSION

These findings suggest that CRM could induce IgE-mediated bronchoconstriction in exposed workers on citrus farm.

A familial predisposition in bronchial hyperresponsiveness among patients with allergic rhinitis

BACKGROUND

Nonasthmatic subjects with allergic rhinitis often have bronchial hyperresponsiveness (BHR). The mechanisms responsible for BHR in asthma include genetic predisposition and airway inflammation, but the causes of BHR in allergic rhinitis are poorly understood.

OBJECTIVE

The aim of this study was to investigate whether there is a familial predisposition in allergic rhinitis-associated BHR.

METHODS

One hundred fifteen children with allergic rhinitis (probands) and their family members underwent methacholine bronchial challenge and skin prick tests with airborne allergens. The probands were divided into 2 groups: BHR(+) (methacholine PC20 <18 mg/mL determined by the dosimeter method; n = 42) and BHR(-) (n = 73).

RESULTS

The overall prevalence of BHR was higher in family members of BHR(+) probands than in those of BHR(-) probands (23.3% [27 of 116] vs 10.5% [21 of 200], P <.01). In mothers, this difference was marked (21.4% vs 8.2%, P <.05); a similar trend was observed in fathers (16.7% vs 6.8%) and siblings (34.4% vs 18.5%), although the differences did not reach significance (.05 < P <.1). The bronchial responsiveness index (BR index), a continuous variable derived from the results of methacholine challenge, was significantly higher among family members of the BHR(+) group than those of the BHR(-) group. Furthermore, even when only family members without BHR were considered, the BR index was significantly higher among those (n = 89) of the BHR(+) group than those (n = 179) of the BHR(-) group. There was no difference in atopic status as assessed by the prevalence of atopy (or atopy index) between family members of the BHR(+) group and the BHR(-) group.

CONCLUSION

Our results indicated that there is a significant familial predisposition for BHR among patients with allergic rhinitis. Further studies are needed to elucidate whether genetic factors play a role in allergic rhinitis-associated BHR.

The occurrence of late asthmatic response to exercise after allergen challenge

BACKGROUND

The determinants of late asthmatic responses to exercise remain unknown. It has been reported that they may develop in some adult subjects with asthma following a late asthmatic response to allergen.

OBJECTIVE

We intended to corroborate this finding in children with asthma and to investigate which aspect of airway responses to allergen is associated with late asthmatic responses to exercise.

METHODS

We studied 17 children with allergic asthma, who showed late asthmatic responses to inhaled allergen (Dermatophagoides pteronyssinus). Each underwent an exercise challenge test two days before (pre-allergen) and two days after (postallergen) an allergen inhalation challenge. FEV1 was measured at regular intervals up to ten hours after each challenge. Methacholine PC20 was measured before the allergen challenge and before the postallergen exercise challenge.

RESULTS

After the pre-allergen exercise test, all the subjects showed isolated early asthmatic responses. After the postallergen exercise test, seven showed dual responses (early and late asthmatic responses) (group I) and the remaining ten showed isolated early asthmatic responses (group II). Bronchial responses to pre-allergen exercise or inhaled allergen and the severity of early asthmatic responses to postallergen exercise were similar in groups I and II. Neither before allergen inhalation nor before the postallergen exercise was methacholine PC20 different between the two groups. Methacholine dose shift caused by allergen challenge, however, was significantly greater in group I than in group II (-2.00+/-0.39 versus -1.36+/-0.53 doubling doses; P < .05). There was significant correlation between the dose shift and the magnitude of late response to the postallergen exercise in the whole group (r = 0.51, P < .05).

CONCLUSION

Late asthmatic responses to exercise may develop in some children with asthma following a late asthmatic response to allergen. This phenomenon was related neither to the baseline nor to postallergen methacholine PC20 but to the extent of increased sensitivity to methacholine caused by allergen challenge.

Prevalence of childhood asthma based on questionnaires and methacholine bronchial provocation test in Korea

BACKGROUND

In most epidemiological survey studies, only subjective symptoms and past medical history of asthma have been used as diagnostic criteria. Even though a questionnaire survey can be performed in a large population study at low cost, limitations such as lack of objectivity and poor predictability in non-specific bronchial hyperresponsiveness cannot be avoided.

OBJECTIVES

The purpose of this study was to elucidate the prevalence of current asthma based on questionnaires and methacholine bronchial provocation test, and the prevalence of atopy in Korea.

METHODS

We performed modified ATS respiratory questionnaires and allergen skin-prick test with 10 common inhalant allergens among 3219 subjects aged 7-19 years in Seoul and a rural part of a small city, Chungju in Korea. Methacholine bronchial provocation tests were also performed among those who had asthma symptoms according to the questionnaire. The criteria of asthma was presence of both asthma symptoms and non-specific bronchial hyperresponsiveness. Atopy was defined as when an allergen induced weal size is same or larger than that caused by histamine.

RESULTS

The prevalence of asthma based on questionnaires and methacholine bronchial provocation tests was 4.6%, while the prevalence of wheeze was 8.2% and 19.3% of total population complained of one or more respiratory symptoms related to asthma on the questionnaires. There was no significant difference according to age, sex and living area. The mean prevalence of atopy was 35.0% and the most common allergens were Dermatophagoides farinae (30.9%), Dermatophagoides pteronyssinus (27.5%), cat fur (20.4%) and cockroach (11.8%). The atopy prevalence in Chungju area was higher than that in Seoul and males showed a higher prevalence than females. The asthma prevalence was higher among atopics (6.8%) than among non-atopics (2.7%). None of questionnaire items were enough to predict the presence of bronchial hyperresponsiveness in terms of sensitivity, specificity and positive predictive value.

CONCLUSION

The prevalence rate of current asthma in Korea was 4.6% and the prevalence rate of atopy in Korea was 35.0%. Questionnaire-based surveys are not enough to predict the actual prevalence of asthma.

Inflammatory cytokine expression on nasal polyps developed in allergic and infectious rhinitis

To investigate the expression of cytokine mRNAs in nasal polyps and the role of allergy in the pathogenesis of nasal polyposis, we studied the expression of IL-4, IL-5, and IFN-gamma mRNAs using the RT-PCR and Southern blot. Nasal polyp specimens were obtained from 14 patients with infectious rhinitis and 5 patients with perennial allergic rhinitis. Turbinate mucosa specimens were obtained from 10 patients with allergic rhinitis and from 10 healthy subjects as controls. IL-4, IL-5 and IFN-gamma mRNA were expressed in most specimens of allergic turbinate mucosa. The expression of these cytokines was less frequent in normal healthy turbinate mucosa. The density ratios of IL-4, IL-5 and IFN-gamma to beta-actin were individually determined in both polyp and turbinate tissues. The density ratio for each cytokine was relatively higher in polyp tissues than in healthy turbinate mucosa; however, there was no significant difference in the density ratios determined for polyps associated with allergic rhinitis as compared with polyps associated with infectious rhinitis. These findings indicate that nasal polyposis may differ from allergic rhinitis in the mechanism by which IL-4 and IL-5 are increased. It is concluded that allergy may have an insignificant role in the development of nasal polyps.

Pathological changes according to the severity of asthma

BACKGROUND

There have been many studies concerning pathological changes in bronchial mucosa from asthmatics; however, few studies has been carried out to evaluate pathological changes according to the severity of asthma.

OBJECTIVE

This study was designed to evaluate the cellular components in bronchoalveolar lavage fluid (BALF) and histological abnormalities in asthmatics according to the severity of asthma.

METHODS

Bronchoalveolar lavages, bronchoscopic biopsies and ultrastructural examinations were performed in 13 asthmatics and 11 (BAL) or four (biopsies) non-asthmatic controls. The proportions of epithelial cells and correlations with PC20Meth which reflects bronchial hyperresponsiveness. Light microscopic examination revealed loss of epithelium, inflammatory cell infiltrations and thickening of the basement membrane which also showed significant correlation with PC20Meth. Hypertrophy of airway smooth muscles and hyperplasia of mucous glands were prominent in asthmatics but there was no difference according to the severity of asthma. Ultrastructural examination revealed that basement membrane thickening on light microscopic examination is due to the increased subepithelial collagen deposition with normal thickness of basal lamina.

CONCLUSION

These data suggest that loss of epithelial cells, infiltration of inflammatory cells, especially eosinophils, and increased deposition of subepithelial collagen play major roles in determining the severity of asthma and non-specific bronchial hyperresponsiveness.

Maximal airway narrowing on the dose-response curve to methacholine is increased after exercise-induced bronchoconstriction

The changes in airway responsiveness between before and after exercise in asthma are not well defined. We investigated the effect of exercise on PC20 (bronchial sensitivity) and maximal airway narrowing (MAN) on the dose-response curve to methacholine in 56 mildly asthmatic children. High-dose methacholine inhalation tests were performed before and 7 hr after exercise challenge. Methacholine PC20 was not changed by exercise, irrespective of exercise-induced bronchoconstriction (EIB). However, the subjects with (+)EIB displayed increased MAN after exercise, whereas those with (+/-)EIB or (-)EIB did not. The results showed that EIB may be followed by increased MAN but not by the change of bronchial sensitivity.

Airway responsiveness to allergen is increased 24 hours after exercise challenge

Although exercise is one of the most ubiquitous triggers of acute bouts of asthma, the changes in airway responsiveness before and after exercise are not well defined. Specifically, the effect of the changes in airway responsiveness induced by exercise has not been studied on subsequent allergen exposure. To test whether the reactivity to allergen is altered by preceding exercise and to define possible factors determining it, we subjected 24 children with atopic asthma to the relevant allergen challenge on two occasions: one as a control without a preceding procedure and the other 24 hours after exercise challenge. Mean postallergen maximal percent falls in forced expiratory volume in 1 second from baseline (delta FEV1) of the whole group were higher after the exercise challenge compared with those of control in both early (< 1 hour) and late (3 to 10 hours) phases. The changes of postallergen maximal delta FEV1 between the control and post-exercise allergen challenges were not related to the early bronchial response to the preceding exercise challenge. Late asthmatic responses to exercise developed in six children, and the changes in both early and late phases were significantly higher in these children, compared with those without late asthmatic responses. Furthermore, the changes were well correlated with the magnitude of the late-phase response to preceding exercise in the group as a whole. It is concluded that an increased airway responsiveness to allergen occurs 24 hours after exercise in some patients with asthma. As the changes are related to a late bronchial response to exercise, late asthmatic response to exercise, when it occurs, may be associated with increased asthmatic symptoms for as long as 24 hours after exercise.

Airways of allergic rhinitics are 'primed' to repeated allergen inhalation challenge

The hypothesis that repeated exposure to a specific allergen will further increase bronchial responsiveness to that allergen is supported by indirect evidence. However, it has not been tested as intensely in the laboratory setting, and in some cases, conflicting results are presented. In order to test the hypothesis in the atopic subjects, allergen inhalation challenge tests were performed in 29 house dust mite (Dermatophagoides pteronyssinus) sensitive subjects with allergic rhinitis. Nine subjects displayed early asthmatic responses (EARs) to the first challenge (Group I). Twenty subjects with no significant airway response were submitted to the second challenge 24 h later. Thirteen subjects showed EARs (Group II) and two of these showed late asthmatic responses (LARs) as well. In Group II, there were significant changes between the first and second challenge in post-allergen early phase FEV1 (88.1 +/- 4.2 vs 71.7 +/- 4.2% baseline, P < 0.05) and in post-allergen late phase FEV1 (93.1 +/- 3.4 vs 86.6 +/- 7.8, P < 0.05). After the second challenge, PD20 (provocative dose of methacholine required to produce a 20% fall in FEV1) decreased significantly from the baseline values. When challenged separately with twofold dose of allergen, only three and one of the Group II showed EAR and LAR respectively. PD20 did not change significantly after this challenge. These results indicated that two repeated exposure to allergen dose, which is not enough to cause significant airway responses at a time, may provoke asthmatic airway responses in the subjects with allergic rhinitis and that this effect of priming is not attributed to the cumulative dose but to the consequent effect of repeated allergen exposure.

Cough variant asthma is associated with a higher wheezing threshold than classic asthma

Cough variant asthma is an occult form of asthma in which the only sign or symptom is chronic cough. It is a common problem amongst all ages that frequently goes unrecognized, leading to underdiagnosis and undertreatment. To characterize the pathophysiological abnormalities in these patients, we performed bronchial provocation tests with methacholine using the stepwise doubling concentration technique, and measured the concentration of methacholine and the severity of airway obstruction when wheezing was first detected. Airway hyperresponsiveness, defined as PC20 in the cough variant asthma group was not significantly different from that of classic asthma. There was a good correlation between the PCW (the concentration of methacholine causing wheezing) and the PC20 with the PCW values higher than PC20 values in both groups. However, in the cough variant asthma group, the PCW:PC20 ratio was greater than that of the classic asthma group. Furthermore, the mean % fall in FEV1 at which wheezing was first detected in the former group was significantly larger than that of the latter group. The results indicated that the mechanism for the manifestation of cough without wheeze in the cough variant asthma may be a higher wheezing threshold, i.e. wheezing becomes audible at the greater degree of airway obstruction than classic asthma. They suggested that patients with cough variant asthma may represent a subset of asthmatic subjects whose airways are less able to produce a wheeze.

Immortalization of mouse bone marrow-derived mast cells with Ad12-SV40 virus

Mast cells arise in cultures of murine bone marrow in medium supplemented with interleukin-3 (IL-3). In the present study, we report the development of long-term mast cell lines from murine bone-marrow-derived cultured mast cells (BMCMC) following inoculation with adenovirus 12-simian virus 40 (Ad12-SV40) hybrid virus. One culture of Ad12-SV40 immortalized BMCMC (designated as MCP-5) was selected for further analysis. These transformed cells appear similar in morphology and histochemistry to the primary BMCMC from which they are derived and did not shed infectious virus into the culture supernatants. In addition, these cells synthesize predominantly chondroitin sulfate proteoglycans and contain histamine which is released following a physiologic stimulus. Limiting-dilution single-cell cloning produced five independent mast cell lines (MCP-5.1 to MCP-5.5). Southern blot analysis of genomic DNA isolated from these single-cell clones demonstrates different patterns of viral integration in all the five clones. All clones retain responsiveness to an exogenous source of IL-3 for growth and proliferation. Each single-cell clone also demonstrates a unique pattern of cytokine gene expression in response to calcium ionophore A23187 and phorbol-12-myristate-13-acetate. This suggests that within a culture of BMCMC there are differences in cytokine gene expression that vary from one cell to another. The availability of immortalized mast cell lines derived from murine bone marrow which retain their growth factor responsiveness and the ability to respond to degranulating stimuli should facilitate future studies of mast cell biology.

Type III hypersensitivity reaction in mushroom growers

Some respiratory symptoms in mushroom growers such as mushroom worker's lung develop by inhalation of certain agents arising from the environment of mushroom cultivation. Recently we observed mushroom workers who had respiratory symptoms which might be type III hypersensitivity reaction to the antigen of Pleurotus floridae. We gave questionnaires to all the mushroom growers at one of the biggest cultivation areas of mushrooms, Pleurotus floridae in Pocheon, Kyunggi Province. Those with respiratory symptoms were subjects for the study. CBC, chest X-ray, pulmonary function test, skin test with Pleurotus floridae extract, and precipitin antibody test to Pleurotus floridae were performed in the study subjects. Out of a total 308 mushroom workers, 23 workers (14 males, 9 females) had respiratory symptoms. Their mean age was 45 years, and their mean duration of engagement was 3.4 years. Their main symptoms were cough (100%), sputum (82.6%), dyspnea (43.5%), and fever with chills (13.0%). Two cases showed increased interstitial lung markings on chest X-ray films. Sixteen cases (73.9%) showed precipitin antibodies against P. floridae extract by counterimmunoelectrophoresis. Antibodies against Micropolyspora faeni and Thermoactinomyces vulgaris were not detected in any subject.