Design of an Integrated Clinical Research Informatics System for a Multi-Centre and Multi-Visit Prospective Birth Cohort Study.

To conduct a multi-center prospective study over more than one year requires an efficient system that can synchronize collection of data from several sources in real-time and facilitate remote data management. This paper describes the design and use of an in-house data collection and sample information management system that was used in a prospective birth cohort study in Thailand. Participants were enrolled from three hospitals and were required to visit their respective hospital and complete self-administered questionnaires (SAQ) at every visit. The in-house informatics system required integration of the data collection streams that can handle three different types of data (SAQ, clinical record, and laboratory sample tracking). The system has been implemented in the pilot phase of a birth cohort study and has demonstrated its usability for further application to an expanded study.

Spatial Estimation of PM2.5 Exposure and its Association with Asthma Exacerbation: A Prospective Study in Thai Children.

Background: The acceptable fine particulate matter (PM2.5) level in Thailand is double the recommendation of the World Health Organization. It is necessary to have an accurate measure of PM2.5 exposure and its association with health problems in vulnerable groups such as asthma exacerbation in Thai children to urge the Clean Air Act in Thailand, which is currently in the process of revision. Objective: To study the association between PM2.5 exposure and asthma exacerbation in children living in Bangkok Metropolitan Region and Chiang Mai Province. Methods: A pilot prospective observational study was conducted at the Chest and Allergy clinic at Ramathibodi Hospital, Mahidol University, Bangkok and at the Chest Clinic at Nakornping Hospital, Chiang Mai, Thailand, from June 2020 to February 2021. Children with asthma, aged 5-18 years old, were recruited. Respiratory symptoms, including cough, chest tightness, dyspnea or wheezing, peak expiratory flow rate, and asthma exacerbation, were recorded twice daily by caregivers. Estimated average daily PM2.5 exposure levels were calculated using ArcGIS® at exacerbation day, three days before exacerbation (lag day 3), and 7 days before exacerbation (lag day 7). Regression analysis was applied to examine the association between PM2.5 exposure and asthma exacerbation. Findings: Seventy asthmatic patients were enrolled. The median age was 9.7 (IQR 5-18) years old. There were 53 respiratory symptoms, 5 admissions, and 1 intensive care unit admission. Daily PM2.5 levels above 12 mcg/m3 (the US cut-off level for the sensitive group) has higher sensitivity to detect asthma exacerbation compared to Thai cut-off level for the sensitive group (37 mcg/m3) (sensitivity 98.2% vs 32.1%). The average daily PM2.5 level exposure at lag day 3 in the exacerbation vs the non-exacerbation group was 27.5 and 13.6 mcg/m3 (p < 0.01), respectively. The daily PM2.5 level at lag day 3 was also correlated with an acute asthmatic attack (r = 0.62, p < 0.01) with the 0.2 events increasing of asthmatic exacerbation every 10 mcg/m3 of increment of daily PM2.5 level. Conclusions: Our findings suggest that asthmatic children are sensitive to daily PM2.5 levels above 12 mcg/m3. Exposure to high daily PM2.5 levels can lead to asthma exacerbation within three days. Further participant recruitment is needed to emphasize this association and establish the national data.

De novo food allergy in pediatric liver transplantation recipients.

BACKGROUND: Food allergy (FA) prevalence is increasing in pediatric liver transplantation (LT). However, the clinical course is still limited. OBJECTIVE: This retrospective cohort study aimed to identify the prevalence, risk factors, and the natural history of de novo FA in children post LT. METHODS: Medical records of pediatric LT recipients from Jan 2001 - Dec 2014 were reviewed. De novo FA was diagnosed by symptoms after exposure to culprit food occurring after LT, and improvement after diet elimination. FA was confirmed if reproduced symptoms after re-challenge or documented sensitization or indicated gastrointestinal eosinophilia. RESULTS: Among 46 post LT children, 54.3% developed de novo FA at a median time of 12.2 months [Interquartile range (IQR) 6.2, 21.3 months] post LT. The confirmed FA was 39.1%. Gastrointestinal symptom was the most common manifestation followed by skin, anaphylaxis, and others. Culprit foods were cow's milk, shellfish, egg, wheat, soybean, peanut, coconut, fish and monosodium glutamate. The risk factors of FA were transplantation during age below 2 years [hazard ratio (HR), 2.62; 95% confidence interval (CI), 1.04 - 6.59; p = 0.03), atopic history in family (HR, 5.67; 95% CI, 1.33 - 24.12; p = 0.01), and Epstein-Barr (EBV) viremia (HR, 2.39; 95% CI, 1.02 - 5.63; p = 0.04). CONCLUSIONS: de novo FA in pediatric LT is not uncommon. Age at LT younger than 2 years, family history of atopy, and EBV viremia are associated with developing FA. Development of tolerance after elimination culprit diets for 3 years is similar to general population.

Children's Environmental Health in Thailand: Past, Present, and Future.

BACKGROUND: There is increasing evidence of a link between environmental pollution and preventable diseases in developing countries, including Thailand. Economic development has generated several types of pollution that can affect population health. While these environmental health effects can be observed throughout life, pregnant women and children represent particularly vulnerable and sensitive groups. METHODS: The published epidemiological literature investigating environmental chemical exposure in Thai children was reviewed, highlighting those that investigated associations between exposure and subsequent health outcomes. RESULTS: The majority of the Thai epidemiological studies on environmental health in children were cross-sectional in design, with some demonstrating associations between exposure and outcome. The three main types of chemical exposure in Thai children were pesticides, heavy metals, and air pollution, which resulted from agricultural activities in countryside areas, industrial zones (both registered and unregistered establishments), mining, and traffic in inner cities. Major health outcomes included detrimental effects on cognitive function and cancer risk. Pesticide exposure was focused on, but not limited to, agricultural areas. The success of the Thai environmental policy to introduce lead-free petrol can be demonstrated by the decline of mean blood lead levels in children, particularly in urban areas. However, unregistered lead-related factories and smelters act as hidden sources. In addition, there is increasing concern, but little acknowledgement, about the effects of chronic arsenic exposure related to mining. Lastly, air pollution remains a problem in both dense city populations due to traffic and in rural areas due to contamination of indoor air and house dust with heavy metals, endotoxins and other allergens. CONCLUSIONS: The increasing number of published articles demonstrates an improved awareness of children's environmental health in Thailand. Chemical hazards, including the improper use of pesticides, environmental contamination with heavy metals (lead and arsenic), and air pollution in inner cities and indoor air, continue to be growing issues.

Association of indoor air quality and preschool children's respiratory symptoms.

BACKGROUND: This study aimed to assess the association between exposure to indoor air pollution in DCCs (Child Day Care Centers) and the respiratory symptoms of children under 6 years old. METHODS: Air quality data were collected three times regarding to seasonal variation. Pollutants measured in 11 DCCs included PM10, CO, NO2, SO2, O3, benzene, bacteria, fungi, and dust mite. The frequencyof respiratory symptoms including coughing, rhinitis, and dyspnea were recorded via teacher and parent-report questionnaires. Fractional exhaled nitric oxide (FENO) levels were measured to assess airway inflammation. RESULTS: 436 children participated in the study. 83% completed data collection in all 3 seasons. The frequency of rhinitis correlated with PM10 (IRR=70.3, 95%CI=12.4-399.7, p<0.001), CO (IRR=3.2, 95%CI=2.4-4.2, p<0.001), benzene (IRR=2.3, 95%CI=1.8-3.2, p<0.001) and D.Pteronyssinus level (IRR=2.1, 95%CI=1.7-2.7, p<0.001). The frequency of coughingcorrelated with levels of PM10 (IRR=15.2, 95%CI=3.0-78.2, p<0.001), CO (IRR=2.8, 95%CI=2.1-3.7, p<0.001), benzene (IRR=1.4, 95%CI=1.1-1.9, p=0.02). The frequency of dyspnea correlated with D.Pteronyssinus level (IRR=3.9, 95%CI=1.7-9.1, p=0.001). FENO levels associated with high benzene levels (OR=5.9, 95%CI=1.5-22.9, p=0.01). The majority of DCCs had at least one PM10 measurement above the standard level, and these high levels were noted in all 3 seasons. Three DCCs had PM10 levels above the standard level in all seasons. 64% of the DCCs had indoor bacterial counts above the standard level in all seasons. CONCLUSIONS: PM10 and bacterial count is a significant problem in Bangkok metropolitan DCCs. The respiratory symptoms of children positively associated with PM10, CO, benzene and dust mite levels.

In vitro cytokine changes after pediatric liver transplantation.

BACKGROUND: Patients with chronic liver disease have been shown to have impaired immune statuses. Liver transplantation (LT) is the standard treatment for end-stage liver disease patients and immunosuppressive drugs are commonly used to prevent graft rejection. There is an increasing evidence of de novo food allergies post LT. OBJECTIVE: To investigate the cytokine response of peripheral blood mononuclear cells (PBMCs) of pediatric LT recipients before and six months after transplantation. METHOD: PBMCs collected before and six months after LT were stimulated with phytohemagglutinin (PHA), beta-lactoglobulin (BLG), tacrolimus (Tac), dexamethasone (Dex), and a combination of BLG and Dex (B+D), BLG and Tac (B+T), BLG and Tac plus Dex (B+T+D). Culture supernatants were measured for IL-5, IFN-γ and IL-10. Blood for liver function tests, complete blood counts, total IgE and specific IgE (sIgE) to cow's milk were recorded. RESULTS: A total of five pediatric LT recipients were enrolled in the study. There were no food allergy cases. Total IgE and sIgE to cow's milk decreased significantly after LT. After transplantation, there was a significant increase in IL-5, IFN-γ and IL-10 in culture supernatants of PHA-stimulated PBMCs. Among different stimulations in post transplantation's PBMCs, the level of IL-5 significantly increased in B+D was suppressed with the combination of B+T+D. The level of IL-10 significantly increased in all conditions containing BLG both before and after transplantation. CONCLUSION: There was an improvement of the in vitro-cytokine responses after liver transplantations. Immunosuppressive drugs used in post transplantation had an effect on the cytokine responses.