Convenient, rapid and economic detection and semi-quantification of American cockroach allergen in the environment.

BACKGROUND: Measuring allergen levels in the environment provides useful information to guide the management of allergic patients. A laboratory-based test kit sandwich ELISA for quantification of Per a 9, the major allergen of Periplaneta americana was recently developed. However, it is not suitable for screening. OBJECTIVE: To develop a simple, rapid, and economic format for semi-quantification of Per a 9 assay using dot-blot ELISA technique. METHODS: The efficacy of direct dot-blot ELISA and sandwich dot-blot ELISA was evaluated. Direct dot-blot ELISA was selected for further modification into 6 protocols. The selected protocol of direct dot-blot was further compared with the laboratory-based test kit, sandwich ELISA. RESULTS: The lowest detection limits in protocols no. 1-6 were 3.9, 15.6, 15.6, 62.5, 125 and 62.5 microg/ml of native Per a 9 whereas time required for each protocol was 145, 45, 30, 26, 18 and 26 minutes, respectively. The sensitivity of direct dot-ELISA was 3.9 microg/ml of Per a 9. Protocol no. 3 was the most suitable assay because its detection limits were as low as 15.6 microg/ml of CR allergen and the total process took only 30 minutes. In comparison with the 2 days required for laboratory sandwich ELISA, the selected protocol provided a similar yield of allergen detection but it offers significant savings of time. Additionally, this method could be easily interpreted by various groups of people. CONCLUSION: This modified direct dot-blot ELISA is the first membrane ELISA which is a semiquantitative test appropriate for screening American cockroach allergen owing to its simplicity, speed and good yield.

Omalizumab in allergic diseases, a recent review.

Omalizumab is a biological engineered molecule, targeting the Cepsilon3 domain of the IgE molecule. It binds with free IgE and prevents free IgE from attaching to high-affinity IgE receptor (FcepsilonRI) on effector cells such as mast cells, basophils and also on dendritic cells. The result is a blocking of mediator release from these cells and the inhibition of antigen presentation by dendritic cells. In addition, omalizumab downregulates FcepsilonRI expression on these effector cells. Omalizumab prevents early and late phase allergic reactions of skin and lungs. Omalizumab has been investigated extensively in moderate-to-severe asthma in adults and children. It effectively reduces rates of asthma exacerbation, emergency visits for asthma and hospital admissions among these patients. Currently, omalizumab is primarily indicated for patients, age 6 years and over, with moderate to severe asthma (GINA step 4). Omalizumab was investigated in patients with seasonal allergic rhinitis (to ragweed, birch and grass pollens) and has been found to improve rhinitis symptoms and to reduce medication use among these patients. Administered together with allergen immunotherapy, omalizumab reduced incidence of side effects and rates of anaphylaxis from allergen immunotherapy. Omalizumab has been investigated in the treatment of food allergy, atopic dermatitis and urticaria. Despite benefits observed from these initial trials, it further deserves investigations to clarify optimal conditions for use in these conditions. Side effects from omalizumab were few, however, it requires careful considerations in administration of this agent. An observational period (up to 2 hours after the first three doses) and the availability of auto-injectable epinephrine are recommended. Pharmacoeconomics of omalizumab is briefly reviewed. Omalizumab represents a major breakthrough of translational medicine in allergy.

The utility of the World Health Organization-The Uppsala Monitoring Centre (WHO-UMC) system for the assessment of adverse drug reactions in hospitalized children.

Although the World Health Organization-The Uppsala Monitoring Centre (WHO-UMC) system has been suggested as a practical tool for classifying adverse drug reactions (ADRs), verification of such system has not been examined. The objective of this study was to evaluate the usefulness of the WHO-UMC classification for the diagnosis of ADRs. The gold standard was the results of drug challenges and serum tryptase in cases of anaphylaxis. Twenty-seven children had ADRs classified by the WHO-UMC system. The causality terms were 'certain' in 4/27, 'probable' in 6/27, 'possible' in 10/27 and 'unlikely' in 7/27 of the patients. Skin prick tests and intradermal tests were positive in 1/20 and 1/5 of the patients, respectively. Drug challenges and serum tryptase were positive in 8/26 and 1/3 of the patients, respectively. After complete evaluation, the positive and negative ADRs were documented in 9/27 patients (33.33%) and 18/27 patients (66.67%), respectively. The multi-level likelihood ratios for ADRs using the WHO-UMC system were infinity in causality term 'certain', 2 in 'probable', 0.5 in 'possible', and 0 in 'unlikely'. In conclusion, causality term 'certain' and 'unlikely' of the WHO-UMC system had large impact on the likelihood of ADRs. In contrast, the causality term 'probable' and 'possible' had small impact on the likelihood of ADRs. Drug challenges and serum tryptase were helpful to confirm ADRs categorized by WHO-UMC system.

Medical charge of asthma care in admitted Thai children.

BACKGROUND: Asthma is one of the most common chronic diseases in children. Due to high admission rate for acute asthmatic attack, children often miss their schools and parents have to stop working to take care of them. These affect both mental and physical health as well as socioeconomic status of the family and the country. OBJECTIVES: To evaluate medical charge of asthma care in children admitted to the Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University. MATERIAL AND METHOD: The study was a retrospective and descriptive study. Data were collected from children with asthmatic attack admitted to the Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand from January 1st, 2000 to June 30th, 2003. Cost of room, food, drugs, devices, laboratory study and service charge were recorded. Total medical charges per year, per patient per admission and per patient per day were calculated. Data were analyzed with Chi square test, ANOVA and Post Hoc test. A p value of < 0.05 was considered statistical significant. RESULTS: Numbers of children with asthmatic attack admitted to the Department of Pediatrics, Siriraj Hospital increased between 2000-2002 (113,147 and 176 in 2000, 2001, and 2002). Seventy two percent of the patients were < or = 5 years of age. Most were mild intermittent asthma. The average duration of hospitalization was 4 days (95% CI, 3.6-4.3). Average medical charge per patient per admission and per day was 3236.20 and 998.60 Bahts respectively. There was no significant difference in the medical charge per patient among the admitted years. Medical charge of admission was significantly associated with the asthma severity. (p < or = 0.05) CONCLUSION: The rate of admission from asthmatic attack in children at Siriraj Hospital and the total medical charge per year increased between 2000-2002. Nevertheless, medical charge of asthma admission per person was unchanged. Main expense in medical charge of asthma admission was the cost of medication and room. Severity of asthma was related directly to medical charge.