PD-1 expression is up-regulated on CD4 and CD19 positive cells during acute <i>P. falciparum</i> infection in children.

<p>A. Flow cytometry plots demonstrating increased expression of PD-1 on CD4⁺ T-cells (top row) and CD19 positive cells (bottom row) on Day 0 (black) compared to Day 28 (white). B. The percentage of programmed death-1 (PD-1) expressing, CD4 and CD19 positive cells in acute uncomplicated P. <i>falciparum</i> malaria infection (white box), on convalescence in the same donors (black box) and in age- and sex- matched healthy controls (grey box). C. The absolute number of programmed death-1 (PD-1) expressing, CD4 and CD19 positive cells in acute uncomplicated P. <i>falciparum</i> malaria infection (white box), on convalescence in the same donors (black box) and in age- and sex- matched healthy controls (grey box). All gates were set using appropriate isotype controls. ^a<i>P</i> values calculated using Wilcoxon rank comparison of matched pairs. ^b<i>p</i> values calculated using Mann-Whitney U statistical comparison of unmatched pairs.</p

EBV lytic and latent peptide pools.

<p><b>Note.</b> – EBNA, Epstein-Barr Nuclear Antigen. LMP, Latency Membrane Protein.</p

PD-1 expression correlates with CD38 expression during acute uncomplicated <i>P. falciparum</i> infection.

<p>PD-1 expression is shown on the y-axis and CD38 expression on the x- axis, each dot represents a single donor during acute (Day 0) uncomplicated P. <i>falciparum</i> malaria. There is a significant correlation between CD38 and PD-1 expression on CD8⁺ T-cells, A, and CD4⁺ T-cells, B.</p

Cellular frequencies in <i>P. falciparum</i> infected and uninfected children.

<p>There is a significant decrease in the numbers of CD3, CD8 and CD4 positive cells in acute uncomplicated <i>P. falciparum</i> malaria (D0, circles), compared to cell numbers during convalescence in the same donors (D28, triangles). The number of CD4 positive cells on convalescence remains significantly lower than age- and sex- matched healthy controls (squares). The number of CD19 positive B-cells doesn't significantly differ. <b>^a</b><i>P</i> value calculated using Wilcoxon rank statistical comparison of matched pairs. <b>^b</b><i>P</i> value calculated using the Mann-Whitney U comparison of unpaired data.</p

EBV genome loads and EBV-specific CD8⁺ T-cell responses did not significantly differ between P. falciparum infected and uninfected children.

<p>A, Epstein-Barr virus (EBV) genome loads during acute uncomplicated P. <i>falciparum</i> malaria infection (n = 31), on convalescence in the same donors (n = 24), and from healthy age- and sex- matched controls (n = 32). The median values, illustrated by the solid black lines, for the groups were 253, 249 and 296 EBV copies/1×10⁶ peripheral blood mononuclear cells respectively. The dashed line represents the lower limit of detection for EBV genomes in the assay. Donors below the dashed line had undetectable viral loads. B, Interferon-gamma (γ)-enzyme linked immunospot assays measured the responses to pools of lytic and latent EBV peptides in 27 donors with acute uncomplicated <i>P. falciparum</i> infection (Day 0), on convalescence in 23 of the same donors (Day 28) and in 32 age- and sex-matched healthy controls. The solid black lines indicate the median responses for each group. C, A flow cytometry plot from a representative donor (ID740) displaying MHC Class I Tetramer (B35 EPL) against CD8⁺ T-cells. D, The percentage of EBV MHC Class I Tetramer (B*35/EPL, A*2/GLC, A*2/CLG or B*8/RAK) positive CD8⁺ T-cells in acute uncomplicated <i>P. falciparum</i> infection (n = 8), on convalescence in the same donors (n = 8) and in age- and sex- matched healthy controls (n = 10). E, The kinetics of the paired MHC class I tetramer responses. F, Regression assays performed on cryopreserved peripheral blood mononuclear cells collected during acute (open bars) and convalescent phases (filled bars) of uncomplicated and complicated <i>P. falciparum</i> malaria infection. The last two donors are EBV seronegative controls. The median values in the acute and convalescent groups were 1.47 and 1.37 respectively (<i>P</i> = 0.60). G, Ex vivo Regression assays performed on healthy control children.</p

Age, sex and haemoglobin levels of uncomplicated <i>P.falciparum</i> cases and aparasitaemic controls.

<p>For age and haemoglobin levels the median value and inter-quartile range are shown in brackets.</p>1<p>p value calculated using Wilcoxon rank statistical comparison of matched pairs.</p>2<p>p value calculated using Mann-Whitney U statistical comparison of unpaired data.</p

Baseline Characteristics of the Study Population.

<p>Baseline Characteristics of the Study Population.</p

Clinical features in Gambian children with severe malaria independently associated with a fatal outcome.

<p>The multiple logistic regression analysis included 1,931 observations with complete data (5 degrees of freedom) χ² = 180.4 (P<0.001); pseudo-R2 = 0.10; Goodness-of- fit, statistics: Hosmer-Lemeshow  = 4.47 (P = 0.61). AUC =  area under the curve.</p

Prevalence of clinical features in Gambian children admitted to hospital with severe malaria.

<p>variables were defined as follows: Prostration, inability to sit (children aged >7 months); Impaired consciousness, BCS ≤4; Coma, BCS ≤2; Repeated convulsions, >3 in 24 h; Severe anemia (with any parasite density), Hb <5 g/dL or PCV <15; Respiratory distress, abnormal respiratory pattern (respiratory pattern values > or  = 3), grunting or use of accessory muscles of respiration, or abnormally deep (acidotic) breathing; Hypoglycemia ≤2.2 mM; Hyperlactatemia, plasma lactate >5 mM; Hyperpyrexia, temp>40°C; Hyperparasitemia, <i>P. falciparum</i> parasite density >500,000 /µl; Hypotensive shock, circulatory collapse with systolic blood pressure <50 mmHg; Hepatomegaly >2 cm below right costal margin; Splenomegaly >2 cm below left costal margin.</p

Clinical features associated with death in children with SM.

<p>Odds of death and blood lactate concentration in children with SM. Data show the odds ratio (95%CI) of death in relation to increasing concentrations of blood lactate in 467 children with SM (a). Odds of death and Blantyre coma score. OR and P values are relative to BCS = 5 (b). Specificity and sensitivity of different blood lactate concentration cut-off values (c) and coma scores measured by BCS (d) to predict death. AUC =  area under the curve,* P<0.05, ***P<0.001.</p