AN OBSERVATIONAL STUDY OF THE EFFECT OF HEMOGLOBINOPATHY, ALPHA THALASSEMIA AND HEMOGLOBIN E ON P. VIVAX PARASITEMIA
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.
Accepted: February 3, 2018
Authors
Background: The protective effect of ?-thalassemia, a common hematological disorder in Southeast Asia, against Plasmodium falciparum malaria has been well established. However, there are much less well understood the effect of ?-thalassemia against P.vivax. Here, we aimed to investigate the proportion of ?-thalassemia including the effect of ?-thalassemia and HbE on the parasitemia of P.vivax in Southeast Asian malaria patients in Thailand.
Methods: A total of 210 malaria patients, admitted to the Hospital for Tropical Diseases, Thailand during 2011-2012, consist of 159 Myanmeses, 13 Karens, 26 Thais, 3 Mons, 3 Laotians, and 6 Cambodians were recruited. Plasmodium spp. and parasite densities were determined. Group of deletion mutation (--SEA, -?3.7, -?4.2deletion) and substitution mutation (HbCS and HbE) were genotyped using multiplex gap-PCR and PCR-RFLP, respectively.
Results: In our malaria patients, 17/210 homozygous and 74/210 heterozygous -?3.7 deletion were found. Only 3/210 heterozygous -?4.2 deletion and 2/210 heterozygous--SEA deletion were detected. HbE is frequently found with 6/210 homozygote and 35/210 heterozygote. The most common thalassemia allele frequencies in Myanmar population were -?3.7 deletion (0.282), followed by HbE (0.101), HbCS (0.016), -?4.2 deletion (0.009), and --SEA deletion (0.003). Only density of P.vivax in ?-thalassemia trait patients (-?3.7/-?3.7, --SEA/??, -?3.7/-?4.2) but not in silent ?-thalassemia (-?3.7/??, -?4.2/??, ??CS/??) were significantly higher compared with non ?-thalassemia patients (p=0.027). Density of P.falciparum significantly increased in heterozygous HbE patients (p=0.046).
Conclusions: Alpha-thalassemia trait is associated with high level of P.vivax parasitemia in malaria patients in Southeast Asia.






