Screening for thalassemia and hemoglobin E in pregnant Laos women at the Mother and Child Health Hospital, Vientiane, Lao People’s democratic republic

ABSTRACT

In order to provide relevant data for implementation of a prevention and control program of thalassemia in Laos population, we have studied the screening for thalassemia and hemoglobin E in pregnant Laos women. Study was conducted on 307 pregnant women attending at the Mother and Child Health hospital, Vientiane, Lao peopleûs Democratic Republic. Initial screening was performed using a combined KKU osmotic fragility (KKU-OF) and KKU dichlorophenolindophenol (KKU-DCIP) tests. Subjects were divided according to the results of OF and DCIP screening tests into 4 groups including 154 (-/-), 58 (+/-), 22 (-/+) and 73 (+/+) individuals. All blood samples were further analyzed on the Hb-HPLC analyzer and by DNA analysis by PCR to identify thalassemia genes. Among 307 subjects examined, 39 cases (12.7 %) had α-thalassemia 1, 11 cases (3.6 %) were β-thalassemia and 93 cases (30.2 %) had Hb E. The effectiveness of screening for the three severe forms of thalassemia namely; α-thalassemia 1, β-thalassemia and Hb E was calculated. The sensitivity, specificity, positive and negative predictive values were 99.2 %, 85.5 %, 83.0 % and 99.4 %, respectively. This result indicates that thalassemia screening is possible and is an effective tool for prevention and control of thalassemia and hemoglobinopathies in Lao P.D.R. With this screening approach, some false positive results might be expected but false negative for the three important forms of thalassemia should be very rare.