Abstracts for the 9th Congress of the Asian Pacific Society of Respirology
10–13 December 2004, Hong Kong

Editors:
Dr K.S. Chan - Dr P.C. Wong

A DOUBLE-BLIND, PLACEBO-CONTROLLED STUDY OF HOUSE DUST MITE IMMUNOTHERAPY IN ASTHMATIC PATIENTS IN CHINA HONGYU WANG1, XIAOPING LIN2, CHUANGLI HAO3, CHUNQING ZHANG1, BAOQING SUN1, JINGPING ZHENG1, PING CHEN2, JINYUN SHENG3, ADRIAN WU4, NANSHAN ZHONG1
1Guangzhou Institute of Respiratory Diseases, 2Shenyang General Military Hospital, 3Suzhou Children’s Hospital, 4Department of Medicine, The University of Hong Kong Background The purpose of this study was to determine if house dust mite immunotherapy is effective in improving symptom control and reducing rescue medication use in Chinese patients with mild to moderate allergic asthma. Methods This is a double-blind, placebo-controlled study involving 132 asthmatic subjects aged 6 to 45 years recruited from 3 different regions of Mainland China. Subjects were given a 52-week course of Alutard Der P (ALK-Abello, Horsholm, Denmark) treatment or placebo while the dose of inhaled corticosteroids (ICS) was maintained.

Results 129 subjects (64 active) completed the study. The symptom scores began to diverge at week 25 with the immunotherapy group showing a significantly lower score until week 48 (P = 0.018). Immunotherapy resulted in a significant decline in symptom (P = 0.003) and medication (P = 0.044) scores during the second half of the treatment period only in subjects who were taking ICS. Subjects on ICS also showed significant improvement in PEF after immunotherapy, but no difference in histamine PC20 was found. Serum ECP and blood eosinophils decreased after immunotherapy in subjects not using ICS. Skin test response decreased in immunotherapy subjects only, and Der P-specific IgE decreased in placebo but not immunotherapy subjects. Immunotherapy resulted in a significantly greater improvement in self-evaluation scores (P < 0.01). Conclusions One year of immunotherapy with Alutard Der P significantly reduced symptoms and medication use in asthmatic subjects, particularly in
those who were already using ICS. This was associated with a greater subjective improvement in asthma control.

ASSOCIATION OF TOTAL PLASMA IGE LEVELS AND ASTHMA IN ASIAN POPULATIONS WD ZHANG, XZ ZHANG, DW QIU, WC TAN
Department of Medicine, National University of Singapore Background Previous studies demonstrated that high levels of serum IgE was associated with asthma and other allergic diseases. Objectives To determine and compare the total plasma IgE levels in both asthmatics and healthy controls in Chinese, Malay and Indian in Singapore. Methods Both 311 asthmatics (Chinese 150; Malay 74; Indian 87) and 355 healthy subjects (Chinese 156; Malay 98; Indian 101) were being participated in a genetic study of asthma. Total plasma IgE levels were determined by Enzyme-linked immunosorbent assay (ELISA). A binary
logistic model was used to detect the association between total plasma IgE levels and asthma.

Results Plasma total IgE was significantly higher in patients group than that of control group in each ethnicity (Chinese: P = 0.049; Malay: P = 0.002; Indian: P = 0.000). Plasma total IgE (Geometric mean) in Chinese (382 IU/ml) was significantly lower than that in Malay (584 IU/ml) and Indian (990 IU/ml) in the patient group (P = 0.000). However, there was no difference for plasma total IgE among Chinese (256 IU/ml), Malay (226 IU/ml) and Indian (323 IU/ml) (P = 0.385) in the control group. Conclusion High level of plasma total IgE may be a risk factor for asthma in Chinese, Malay and Indian. Total plasma IgE levels showed homogeneous among the three ethnicities.