In vitro infection of G6PD-deficient patients’ monocytes with dengue virus serotype 2

Dengue virus is a member of family Flaviviridae. There are four serotypes of dengue virus, DENV-1, DENV-2, DENV-3 and DENV-4. The vectors of dengue virus are Aedes albopictus and Aedes aegypti and dengue virus can cause mild dengue fever (DF), or severe dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). Favism is a disease resulting from deficiency of Glucose-6-phosphate dehydrogenase, G6PD. The G6PD deficiency patients are easier infected by bacteria or virus even develop chronic granulomatous disease (CGD). In average, the prevalence of G6PD deficiency is about 3% in Taiwan and Taiwan is also an epidemic area of dengue virus. To study whether G6PD deficiency patients are susceptible to dengue virus and the infection is easier to cause severe syndrome. We have collected twelve G6PD deficiency patients and twenty four normal people to investigate. Monocytes were isolated from peripheral blood mononuclear cell (PBMC) and these monocytes were in vitro infected by two different strain of dengue virus serotype 2 (New Guinea C and 16681) at multiplicity of infection (MOI)= 0.1. After culturing for three days, the monocytes were double stained and analyzed by flowcytometer.
The result found that the average infection rate of New Guinea C to normal people monocytes was 20.23±6.22 % (8.03 % ~ 30.40 %) and to G6PD deficiency patients’ monocytes was 33.36±3.48 % (27.20 % ~ 39.16 %) (p<0.01). The average infection rate of 16681 to normal people monocytes was 27.41±7.11 % (12.29 % ~ 37.10 %) and to G6PD deficiency patients’ monocytes was 40.74±3.73 % (35.06 % ~ 48.87 %) (p<0.01). According to the results, G6PD deficiency patients’ monocytes had statistically significant higher infection rate than normal ones even in New Guinea C or 16681. In addition, 16681 has higher infection rate than New Guinea C both in G6PD deficiency patients’ monocytes and normal ones (p<0.05).
In conclusion, this study demonstrates that the host factor plays an important role in the infection of dengue virus. In addition, the infection rate of different strains of dengue viruses in the same host was not the same. The strain of dengue virus 16681, isolated from DHF/DSS, possesses better ability to infect human monocytes than New Guinea C isolated from dengue fever. Therefore, we can apply theses above finding in educating patients with favism to avoid dengue virus infection and thus minimize their healthy threat.