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Dengue viral RNA levels in peripheral blood mononuclear cells are associated with disease severity and preexisting dengue immune status.

Srikiatkhachorn A, Wichit S, Gibbons RV, Green S, Libraty DH, Endy TP, Ennis FA, Kalayanarooj S, Rothman AL - PLoS ONE (2012)

Bottom Line: Viral RNA levels in CD14+ cells and plasma were significantly higher in DHF compared to DF, and in cases with a secondary infection compared to those undergoing a primary infection.The distribution of viral RNA among cell subpopulations was similar in DF and DHF cases.Small amounts of negative strand RNA were found in a few cases only.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America. anon.srikiatkhachorn@umassmed.edu

ABSTRACT

Background: Infection with dengue viruses (DENV) causes a wide range of manifestations from asymptomatic infection to a febrile illness called dengue fever (DF), to dengue hemorrhagic fever (DHF). The in vivo targets of DENV and the relation between the viral burden in these cells and disease severity are not known.

Method: The levels of positive and negative strand viral RNA in peripheral blood monocytes, T/NK cells, and B cells and in plasma of DF and DHF cases were measured by quantitative RT-PCR.

Results: Positive strand viral RNA was detected in monocytes, T/NK cells and B cells with the highest amounts found in B cells. Viral RNA levels in CD14+ cells and plasma were significantly higher in DHF compared to DF, and in cases with a secondary infection compared to those undergoing a primary infection. The distribution of viral RNA among cell subpopulations was similar in DF and DHF cases. Small amounts of negative strand RNA were found in a few cases only. The severity of plasma leakage correlated with viral RNA levels in plasma and in CD14+ cells.

Conclusions: B cells were the principal cells containing DENV RNA in peripheral blood, but overall there was little active DENV RNA replication detectable in peripheral blood mononuclear cells (PBMC). Secondary infection and DHF were associated with higher viral burden in PBMC populations, especially CD14+ monocytes, suggesting that viral infection of these cells may be involved in disease pathogenesis.

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Dengue virus in plasma and peripheral blood mononuclear cells.Comparisons of dengue viral (DENV) RNA levels in plasma and PBMC subpopulations in DF and DHF cases two days prior to defervescence (fever day −2) (A). * indicates statistically significant differences in DENV RNA levels between DF and DHF (P<.05). +indicates differences between DENV RNA levels in CD20+ cells compared to CD14+ and CD2+ cells (P<.05). (B, C, D, E) Levels of DENV RNA levels in plasma (B), CD14+ (C), CD2+ (D) and CD20+ (E) cells on fever day −2 and fever day −1. Each line represents individual cases: solid lines: DHF, dashed lines: DF.
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pone-0051335-g001: Dengue virus in plasma and peripheral blood mononuclear cells.Comparisons of dengue viral (DENV) RNA levels in plasma and PBMC subpopulations in DF and DHF cases two days prior to defervescence (fever day −2) (A). * indicates statistically significant differences in DENV RNA levels between DF and DHF (P<.05). +indicates differences between DENV RNA levels in CD20+ cells compared to CD14+ and CD2+ cells (P<.05). (B, C, D, E) Levels of DENV RNA levels in plasma (B), CD14+ (C), CD2+ (D) and CD20+ (E) cells on fever day −2 and fever day −1. Each line represents individual cases: solid lines: DHF, dashed lines: DF.

Mentions: On the basis of previous studies indicating that viremia declines at the time of defervescence [2] we selected plasma and PBMC samples collected prior to defervescence for this analysis. PBMCs were fractionated into CD14+ (monocytes), CD2+ (T and NK cells), and CD20+ (B cells) cell fractions. The purity of each fraction exceeded 90%, as assessed by flow cytometry. Quantitative RT-PCR of fractionated cell RNA detected DENV RNA in all fractions (Figure 1), with CD20+ cells harboring higher viral RNA levels compared to CD14+ cells and CD2+ cells. The distribution of DENV RNA among cell populations was similar in DF and DHF. Plasma DENV RNA levels were significantly higher in DHF cases compared to DF cases (p = .001) (Figure 1A). The CD14+ cell fractions from DHF cases also contained higher DENV RNA levels than those from DF cases (p = .01). Plasma viral RNA levels declined significantly from fever day −2 to fever day −1 in all cases (p = .001) (Figure 1B). The viral RNA in cell fractions did not change significantly between these 2 time points) (Figure 1 C, D, E). To examine the effects of host serological status on cellular viral burden, we compared the levels of DENV RNA in PBMC subpopulations of 11 primary and 15 secondary DENV infections, all of whom had DF. As shown in figure 2, viral RNA levels in CD14+ and CD2+ cell fractions were higher in patients with secondary infection than those with primary infection. There was no significant difference in plasma viral RNA levels between primary and secondary infections.


Dengue viral RNA levels in peripheral blood mononuclear cells are associated with disease severity and preexisting dengue immune status.

Srikiatkhachorn A, Wichit S, Gibbons RV, Green S, Libraty DH, Endy TP, Ennis FA, Kalayanarooj S, Rothman AL - PLoS ONE (2012)

Dengue virus in plasma and peripheral blood mononuclear cells.Comparisons of dengue viral (DENV) RNA levels in plasma and PBMC subpopulations in DF and DHF cases two days prior to defervescence (fever day −2) (A). * indicates statistically significant differences in DENV RNA levels between DF and DHF (P<.05). +indicates differences between DENV RNA levels in CD20+ cells compared to CD14+ and CD2+ cells (P<.05). (B, C, D, E) Levels of DENV RNA levels in plasma (B), CD14+ (C), CD2+ (D) and CD20+ (E) cells on fever day −2 and fever day −1. Each line represents individual cases: solid lines: DHF, dashed lines: DF.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3526575&req=5

pone-0051335-g001: Dengue virus in plasma and peripheral blood mononuclear cells.Comparisons of dengue viral (DENV) RNA levels in plasma and PBMC subpopulations in DF and DHF cases two days prior to defervescence (fever day −2) (A). * indicates statistically significant differences in DENV RNA levels between DF and DHF (P<.05). +indicates differences between DENV RNA levels in CD20+ cells compared to CD14+ and CD2+ cells (P<.05). (B, C, D, E) Levels of DENV RNA levels in plasma (B), CD14+ (C), CD2+ (D) and CD20+ (E) cells on fever day −2 and fever day −1. Each line represents individual cases: solid lines: DHF, dashed lines: DF.
Mentions: On the basis of previous studies indicating that viremia declines at the time of defervescence [2] we selected plasma and PBMC samples collected prior to defervescence for this analysis. PBMCs were fractionated into CD14+ (monocytes), CD2+ (T and NK cells), and CD20+ (B cells) cell fractions. The purity of each fraction exceeded 90%, as assessed by flow cytometry. Quantitative RT-PCR of fractionated cell RNA detected DENV RNA in all fractions (Figure 1), with CD20+ cells harboring higher viral RNA levels compared to CD14+ cells and CD2+ cells. The distribution of DENV RNA among cell populations was similar in DF and DHF. Plasma DENV RNA levels were significantly higher in DHF cases compared to DF cases (p = .001) (Figure 1A). The CD14+ cell fractions from DHF cases also contained higher DENV RNA levels than those from DF cases (p = .01). Plasma viral RNA levels declined significantly from fever day −2 to fever day −1 in all cases (p = .001) (Figure 1B). The viral RNA in cell fractions did not change significantly between these 2 time points) (Figure 1 C, D, E). To examine the effects of host serological status on cellular viral burden, we compared the levels of DENV RNA in PBMC subpopulations of 11 primary and 15 secondary DENV infections, all of whom had DF. As shown in figure 2, viral RNA levels in CD14+ and CD2+ cell fractions were higher in patients with secondary infection than those with primary infection. There was no significant difference in plasma viral RNA levels between primary and secondary infections.

Bottom Line: Viral RNA levels in CD14+ cells and plasma were significantly higher in DHF compared to DF, and in cases with a secondary infection compared to those undergoing a primary infection.The distribution of viral RNA among cell subpopulations was similar in DF and DHF cases.Small amounts of negative strand RNA were found in a few cases only.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America. anon.srikiatkhachorn@umassmed.edu

ABSTRACT

Background: Infection with dengue viruses (DENV) causes a wide range of manifestations from asymptomatic infection to a febrile illness called dengue fever (DF), to dengue hemorrhagic fever (DHF). The in vivo targets of DENV and the relation between the viral burden in these cells and disease severity are not known.

Method: The levels of positive and negative strand viral RNA in peripheral blood monocytes, T/NK cells, and B cells and in plasma of DF and DHF cases were measured by quantitative RT-PCR.

Results: Positive strand viral RNA was detected in monocytes, T/NK cells and B cells with the highest amounts found in B cells. Viral RNA levels in CD14+ cells and plasma were significantly higher in DHF compared to DF, and in cases with a secondary infection compared to those undergoing a primary infection. The distribution of viral RNA among cell subpopulations was similar in DF and DHF cases. Small amounts of negative strand RNA were found in a few cases only. The severity of plasma leakage correlated with viral RNA levels in plasma and in CD14+ cells.

Conclusions: B cells were the principal cells containing DENV RNA in peripheral blood, but overall there was little active DENV RNA replication detectable in peripheral blood mononuclear cells (PBMC). Secondary infection and DHF were associated with higher viral burden in PBMC populations, especially CD14+ monocytes, suggesting that viral infection of these cells may be involved in disease pathogenesis.

Show MeSH
Related in: MedlinePlus