An Observational Study of the Effect of Hemoglobinopathy, Alpha Thalassemia and Hemoglobin E on P. Vivax Parasitemia

作者：Para Suparak; Mungkalasut Punchalee; Chanda Makamas; Nuchprayoon Issarang; Krudsood Srivicha; Cheepsunthorn Chalisa Louicharoen^*

来源：Mediterranean Journal of Hematology and Infectious Diseases, 2018, 10(1): e2018015.

DOI：10.4084/MJHID.2018.015

• Silent alpha-thalassemia
• Alpha-thalassemia trait
• HbE
• Malaria
• Southeast Asian

Background: The protective effect of alpha-thalassemia, a common hematological disorder in Southeast Asia, against Plasmodium falciparum malaria has been well established. However, there is much less understanding of the effect of alpha-thalassemia against P. vivax. Here, we aimed to investigate the proportion of alpha-thalassemia including the impact of alpha-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, consisting 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), -alpha(3.7), -alpha(4.2) deletion) 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 -alpha(3.7) deletion were found. Only 3/210 heterozygous -a4.2 and 2/210 heterozygous--(SEA) deletion were detected. HbE is frequently found with 6/210 homozygotes and 35/210 heterozygotes. The most common thalassemia allele frequencies in Myanmar population were -alpha(3.7) deletion (0.282), followed by HbE (0.101), HbCS (0.013), -alpha(4.2) deletion (0.009), and --(SEA) deletion (0.003). Only density of P. vivax in alpha-thalassemia trait patients (-alpha(3.7)/-alpha(3.7), --(SEA)/alpha alpha, -alpha(3.7)/-alpha(4.2)) but not in silent alpha-thalassemia (-alpha(3.7)/alpha alpha, -alpha(4.2)/alpha alpha, alpha alpha(CS)/alpha alpha) were significantly higher compared with non-alpha-thalassemia patients (p=0.027). HbE did not affect P. vivax parasitemia. The density of P. falciparum significantly increased in heterozygous HbE patients (p=0.046).
Conclusions: Alpha-thalassemia trait is associated with high levels of P. vivax parasitemia in malaria patients in Southeast Asia.

• 出版日期2018-2-16