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Objective: To access the relationship between atopy and bronchial asthma in adolescents., Methods: A cross-sectional study was conducted. Cluster randomized subgroups of schoolchildren who had participated in ISAAC phase III survey in Guangzhou were enrolled from april to May, 2002. Skin prick test with 5 groups totally for 9 common aeroallergens (dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, Alternaria tenuis, mixed tree pollen, mixed grass pollen, American cockroach, German cockroach and mixed moulds) was performed. Asthma was defined as wheezing or whistling in the chest in the lifetime or in the last 12 months, or diagnosed asthma. Allergy disease was defined as any of asthma, rhinitis and eczema. A wheal size with the diameter of 3 mm or more after subtraction of the negative control was considered as positive and subjects with one or more positive reactions were considered as atopy. The degree of atopy and the sensitivity of the allergen were graded by atopic index (AI) and skin index (SI), respectively., Results: 1543 subjects were selected randomly for the skin prick test, and the response rate was 77.0% (1187/1543). 51.6% (613/1187) were males and 48.4% (574/1187) were females. The median age was 14 years old (range from 12 - 17 years old). The prevalence of asthma was 9.4% (111/1187), among whom 81.1% (90/111) also had rhinitis and 24.3% (27/111) had eczema. Asthma was more prevalent in 686 patients with rhinitis [13.1% (90/686)] or 200 patients with eczema [13.5% (27/200)] than those without rhinitis [4.2% (21/501), OR: 3.444, 95% CI: 2.110 - 5.622, P < 0.01] or eczema [8.5% (84/987), OR: 1.676, 95% CI: 1.055 - 2.663, P < 0.05]. The prevalence of atopy was 46.3% (549/1187) and the positive rates of house dust mite (Der p and Der f) were the highest [41.8% (496/1187) and 42.7% (507/1187), respectively]. Atopy was more common in asthmatic patients [71.2% (79/111)] than in those without any allergic diseases [26.4% (112/425), OR: 6.812, 95% CI: 4.276 - 10.853, P < 0.01]. Asthma was more prevalent in patients with atopy (14.4%) than those without atopy (5.5%, OR: 3.183, 95% CI: 2.075 - 4.883, P < 0.01). The relative risk of having asthma was increased with the higher AI degree. Univariate Logistic regression analysis showed that the risk factors for asthma were Der p (SI >/= 2), Der f (SI = 3 - 4), American cockroach, German cockroach, cat, Alternaria tenuis, mixed grass pollen. Multivariate Logistic regression analysis showed that Der p (SI = 3 - 4), and Alternaria tenuis were independent risk factors for asthma., Conclusion: Most asthmatic adolescents were allergic to house dust mite in the city of Guangzhou. The risk of asthma was positively correlated with the degree of atopy, as well as the sensitivity to Der p.

Objective: To evaluate the clinical efficacy and safety of specific immunotherapy (SIT) with standardized house dust mite (HDM) vaccine on allergic asthmatic patients., Methods: The investigation was a multicentre, randomized, double-blind, placebo-controlled clinical study. 132 patients with mild to moderate asthma who were allergic to HDM, recruited from three hospitals of China (The First Affiliated Hospital of Guangzhou Medical College, Shenyang General Military Hospital, Suzhou Children's Hospital), were randomly allocated to the active group (n = 66) or the control group (n = 66) respectively. The active group received SIT with a standardized depot Dermatophagoides pteronyssinus (Der p) extract absorbed to aluminium hydroxide (Alutard SQ, ALK-Abelló, Denmark), while the control group received a placebo containing histamine dihydrochloride by subcutaneous injections for 1 year. Treatment of each group was started from the initial concentration. Updosing was performed with weekly injections from four 10-fold dose-increase vials (active group: 100, 1,000, 10,000, 100,000 SQ-U/ml, control group: 0.01, 0.1, 1.0, 10 microg/ml. 100,000 SQ-U/ml of Der p extract contains 9.8 microg/ml of the majoy allergen Der p1). The single-dose was injected weekly with 0.2, 0.4, 0.8 ml of each concentration in turn from the preceding 3 vials, totally for 9 weeks. Subsequently, the dose with 0.1, 0.2, 0.4, 0.6, 0.8 ml of the highest concentration was injected weekly from the 10th-14th week and a maintenance dose with 1 ml was reached at the 15th week. The dosing interval was then gradually increased to 2, 4, 6 weeks until the end of the first 26-weeks updosing phase (phase I, H(1)). Thereafter, the dosing continued at 6-week intervals for maintenance phase (phase II, H(2)) till the end of the complete treatment. The patient was observed for at least 30 minutes in the clinic after each injection., Results: A total of 132 subjects were randomized and 129 subjects (64 in the active group, 65 in the control group) completed the whole study. Dropouts included three females because of poor compliance, being afraid of the epidemic of Severe Acute Respiratory Syndrome (SARS) and emigration respectively. Both groups were comparable at baseline in all clinical and laboratory parameters. The mean daily symptom scores in 4-weekly began to diverge at the 29th-32nd week with the active group showing a significant lower scores (0.17 +/- 0.33) than the control group (0.39 +/- 0.74, Z = 2.031, P < 0.05) till the end of the study. Significant difference was found in average daily symptom scores between H(1) (0.29 +/- 0.39) and H(2) (0.19 +/- 0.27) in the active group (Z = 2.923, P < 0.01), while no significant difference was found between H(1) (0.45 +/- 0.62) and H(2) (0.40 +/- 0.68) in the placebo group (Z = 1.885, P > 0.05). There were significant differences in subjective judgement of the improvement about overall asthmatic symptoms, exacerbation severity and exacerbation frequency between the active group (96.9%, 95.3%, 95.4%) and the control group (80.0%, 75.4%, 83.1%) with the self-evaluation questionnaire (chi(2) = 13.246, 11.576, 16.204, all P < 0.01). The trend line of daily medication scores in weekly intervals showed a significant decline. The mean daily medication score of phase II (0.20 +/- 0.36) was significant lower than that of phase I (0.33 +/- 0.67, Z = 3.344, P < 0.01), whereas the control group did not show a significant difference between phase II (0.35 +/- 0.96) and phase I (0.32 +/- 0.95, Z = 0.744, P > 0.05). After 1-year treatment, no significant differences were found in morning and evening peak expiratory flow of predicted value (PEF%), forced expiratory volume in one second of predicted value (FEV(1)/FVC), forced vital capacity of predicted value (FVC%), forced expiratory volume in one second to forced vital capacity ratio (FEV(1)/FVC), provoking dose decreasing FEV(1) by 20% (PD(20)-FEV(1)) between the active group [(97 +/- 17)%, (98 +/- 18)%, (91 +/- 11)%, (98 +/- 9)%, (82 +/- 10)%, 2.35 (7.9) micromol] and the control group [(99 +/- 19)%, (100 +/- 19)%, (90 +/- 14)%, (99 +/- 13)%, (82 +/- 9)%, 1.80 (7.8) micromol] (t = 0.170 - 0.630, Z = 0.264, all P > 0.05). Skin index (SI) to Der p in the active group (1.2 +/- 0.5) was significantly lower than that of the control group (1.5 +/- 0.6) after treatment (t = 2.395, P < 0.05). There was no significant difference in the level of serum sIgE against Der p between groups, which was 76.80 (97.0) kU/L in active group and 66.50 (99.3) kU/L in the control group (Z = 0.232, P > 0.05). The frequency of systemic adverse reactions graded by guidelines based on the position paper of European Academy of Allergology and Clinical Immunology (EAACI), was 5.7% and 1.8% of the total injections in the active group and the control group, respectively. Although significant difference was found in adverse reactions between groups (chi(2) = 4.705, P < 0.05), all were mild or moderate. The majority occurred within 30 minute after injection and were controlled well with symptomatic therapy. No any severe systemic adverse reaction was shown in the study., Conclusion: One year specific immunotherapy with standardized house dust mite (HDM) vaccine significantly improved symptoms and reduced medication use in mild to moderate allergic asthmatic patients. SIT also reduced skin prick test reactivity to Der p. Complying with the EAACI immunotherapy guidelines, SIT with standardized HDM vaccine was a safe treatment.

Objective: To explore the spectrum and frequency of causes for chronic cough in Chinese patients., Methods: 86 patients with chronic cough were enrolled in the study. The diagnostic procedure was based on the anatomical protocol for diagnosing chronic cough designed by Irwin, and additional cytological assay was performed for sputum induced by hypertonic saline aerosol inhalation. The efficacy of therapy specific to the diagnosis was evaluated., Results: Definite diagnosis was made in 77 (89.5%) out of the 86 patients with chronic cough. The most common causes included cough variant asthma (CVA) (24/86, 27.9%), postnasal drip syndrome (PNDs) (22/86, 25.6%), eosinophilic bronchitis (EB) (13/86, 15.1%), and gastroesophageal reflux (GER) (12/86, 14.0%). After active management based on the diagnosis, cough improved in 72 patients (93.5%)., Conclusions: In addition to CVA, PNDs and GER, eosinophilic bronchitis is also an important cause of chronic cough. A positive response to the specific therapy is essential to a definite diagnosis.

Objective: To study the clinical features and airway inflammation in eosinophilic bronchitis (EB) and the treatment outcomes., Methods: Irwin's anatomic protocol for diagnosing chronic cough was used in 86 patients with chronic cough, and induced sputum by hypertonic saline aerosol inhalation was performed. Differential cell counts were performed in induced sputum, and eosinophilic cationic protein (ECP) was measured with fluoroimmunoassay, while interleukin-8 (IL-8) was measured with enzyme-linked absorbed immunoassay. EB was diagnosed according to Gibson's criteria and treated with inhaled budesonide 200 - 400 micro g twice daily for four weeks, and in some patients oral prednisone 10 - 15 mg/d or methyl-prednisone 8 - 12 mg/d was given for one week., Results: 13 (15%) out of 86 patients with chronic cough were diagnosed as having EB. Dry cough was the major compliant and all had normal lung function with negative histamine provocation test. The Eos count was 0.1862 +/- 0.1632 and the concentration of ECP (2.53 +/- 2.07) mg/L in induced sputum were significant higher in patients with EB as compared with those normal subjects (P < 0.01). The cough disappeared in all patients at the end of one week of inhaled or orally administered corticosteroids., Conclusion: EB, an eosinophilic airway inflammation, is one of important causes of chronic cough and responds well to corticosteroid therapy.