Screening for alpha and beta thalassemia diseases by Hb H inclusion and Hb F cell staining at Somdejprayannasangworn Hospital, Chiang Rai province

Abstract

a – And b - thalassemia diseases are common in Thailand. Diagnosis of the diseases are usually made by clinical and Hb analyses. Hb H (b₄) is usually detected in the Hb H disease and Hb F (a₂g₂) is observed in b-thalassemia. As Hb analysis is generally served at big health centers, samples from small hospitals have to be sent for analysis which usually requires at least 1 week. To provide useful data for rapid initial diagnosis at small hospital, study was done at Somdejprayannasangworn hospital, Chiang Rai province to determine the accuracy of diseases screening using Hb H inclusion and Hb F cell staining tests. Blood samples of 30 subjects who were suspected for thalassemias by the doctor and those of 32 anemic samples were initially examined for Hb H inclusion and Hb F cells at this hospital. Remaining blood samples were sent to the Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, for Hb and DNA analyses. It was found that all 22 patients with Hb H disease and two a-thalassemia 1 carriers were positive for Hb H inclusion test. The sensitivity and specificity of the test for diagnosis of Hb H disease were 100 % and 95.0 %, respectively. Among 10 subjects with b-thalassemia / Hb E disease, 9 were positive for Hb F cell staining. False positives were observed in 9 subjects. The sensitivity and specificity of the test for diagnosis of b-thalassemia disease were 90.0 % and 82.7 %, respectively. These results demonstrate that Hb H inclusion and Hb F cell staining could provide useful data for initial diagnoses of a – and b-thalassemia diseases at a small hospital.