Evaluation of skin prick test to screen dust mite sensitization in chronic respiratory diseases in Southern Vietnam

BACKGROUND: In the view of the epidemic growth of sensitization to indoor allergens in Southern Vietnam, there is a requirement to screen large population. OBJECTIVE: To evaluate skin prick tests (SPTs) as predictors of positive specific IgE (sIgE) to dust allergens, among patients with chronic respiratory diseases (CRDs). METHODS: The sensitization to Blomia tropicalis (Blo t), Dermatophagoides pteronissinus (Der p), and Blattella germanica allergens (Bla g) were evaluated among 610 CRD, both SPT (≥4 mm) and sIgE by immuno-CAP (≥0.7 kUA/L). RESULTS: Based on sIgE, 45%, 32%, and 33% of patients with CRD were sensitized to Blo t, Der p, and Bla g, respectively, compared to 19%, 18%, and 13% by SPT. The association between SPT and sIgE was statistically significant, though the Kappa factor was fair (i.e., 0.39 to 0.23). While the specificity of SPT to detect sensitization (compared to sIgE) was >90% among the whole population, the sensitivity was only 34%, 41%, and 24% for Bo t, Der p, and Bla g, suggesting that SPT was not enough sensitive to screen the indoor allergen sensitization. Though, among the < 10 pack-year (PY) smokers, the sensitivity was 43% for Blo t, 52% for Der p, and 61% for Blo t and/or Der p, compared to 27%, 30%, and 35% among the ≥10 PY smokers. The sensitivity/specificity was not associated with the diagnosis of asthma compared to chronic obstructive pulmonary disease. CONCLUSION: In the present circumstance, SPT to dust mites allergens can be used to detect a sensitization among CRD population in Southern Vietnam.

The effect of antenatal betamethasone on prevent respiratory distress syndrome in premature infants

A retrospective controlled cohort analysis of live-born singleton neonates prematurely born before 34 weeks’gestation was conducted in Tu Du Maternity Hospital in HCMC from January 2000 to December 2000. 217 premature infants were devided into 2 groups: group 1: 80 infants, whose mother taking prenatal betamethasone and group 2: 137 infants, whose mother without taking prenatal betamethasone. Data were analyzed with the T test, the Chi square test and Fisher exact test. Relative risk, 95% confident interval, other maternal and infant factors were calculated for betamethasone use. The results: the independent variables, which included maternal demographic, maternal clinical risk, infant characteristics were controlled. There were a significant statistical difference for Respiratory distress syndrome incidence of infants between 2 groups. Mean duration of ventilator and mean duration of neonatal hospital care were statistically different. All other short term side effects analyzed were similar between 2 groups