The density of knobs on the surface of erythrocytes infected by isolate GH18 after prolonged culture <i>in vitro</i>.

<p>The relationship between time since invasion and IE surface knob density after <i>in vitro</i> culture of isolate GH18 for 8 weeks (A) or 12 weeks (B). All time/density data points <36 h as well as the common regression line (with 95% confidence interval) for the GH18 (note that the <i>ex vivo</i> data points shown in Fig. 2M are included) (C). Individual data points, as well as the linear regression line (with 95% confidence limits) for data points <36 h are shown. Adjusted regression lines (assuming parallelism) after different times of <i>in vitro</i> culture of isolate GH18 (D).</p

The density of knobs on the surface of erythrocytes infected by long-term in vitro isolates of <i>P. falciparum</i> expressing the PfEMP1 protein VAR2CSA.

<p>The relationship between time since invasion (h) and IE surface knob density (µm^–2) on erythrocytes infected by 10 genotypically distinct isolates of <i>P. falciparum</i> (isolate name in brackets), maintained in long-time <i>in vitro</i> culture and selected for expression of the PfEMP1 protein VAR2CSA by regular panning for IE adhesion to CSA (A-J). Individual data points, as well as the linear regression line (with 95% confidence limits) for data points <36 h are shown for each isolate.</p

Covariance analysis of the relationship between knob density and time since invasion.

<p>All time/density data points <36 h as well as the common regression line (with 95% confidence interval) for the Ghanaian <i>ex vivo</i> isolates (A) and the laboratory isolates selected for VAR2CSA expression <i>in vitro</i> (C). Adjusted regression lines (assuming parallelism) of individual Ghanaian (B) and VAR2CSA-expressing isolates (D).</p

Parasite developmental age and infected erythrocyte knob density.

<p>Example atomic force micrographs of erythrocytes infected by a early schizont parasite <i>ex vivo</i> (A) or by a younger VAR2CSA-expressing trophozoite (B). Black scale bars: 1 µm. The inserts show light micrographs of the same infected erythrocytes stained by Giemsa. Close-up micrographs of knobs (C) and of a single knob (D). Black scale bars: 200 nm (C), 75 nm (D).</p

Merozoite-specific IgG according to clinical category.

<p>Levels (AU) of IgG specific for PfRH5 (A), CyRPA (B), Pf113 (C), EBA175 (D), GLURP-R0 (E) and GLURP-R2 (F) in plasma of individual children according to clinical category: SM (severe P. falciparum malaria), UM (uncomplicated P. falciparum malaria), FC (non-parasitemic febrile controls), AC (asymptomatic controls), HC (non-parasitemic healthy controls). Please refer to Materials and Methods for category definitions. The number of individuals with IgG above cut-off and the total number of individuals in each clinical category are given along the top of each panel. Horizontal lines along the top of the panels indicate statistically significant (P<0.05) differences between groups. Data presentation otherwise as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198371#pone.0198371.g001" target="_blank">Fig 1B</a>. The presented data is from one experiment.</p

Clinical characteristics of study participants.

<p>Clinical characteristics of study participants.</p

Kinetics of merozoite-specific IgG levels following episodes of <i>P</i>. <i>falciparum</i> malaria.

<p>Plasma levels of IgG specific for PfRH5 (A, D), CyRPA (B, E), and Pf113 (C, F) in children with P. falciparum malaria (Day 0), and in the same children two weeks (Day 14) and six weeks (Day 42) later. Temporal changes in levels of IgG in individual children (A-C) and in the cohort mean IgG level (D-F). Data from individual children are connected by lines (A-C). Cohort running means (heavy lines) and their 95% confidence intervals (thin lines), calculated as described previously [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198371#pone.0198371.ref034" target="_blank">34</a>], as well as calculated catabolic decay from Day 14 (dashed lines) are shown (D-F). Negative cut-offs (shaded areas) are shown (all panels). The presented data is from one experiment.</p

Correlations (Spearman’s ρ [associated P-values] of IgG responses.

<p>Correlations (Spearman’s ρ [associated P-values] of IgG responses.</p

Merozoite-specific IgG in acutely ill <i>P</i>. <i>falciparum</i> malaria patients.

<p>A: Prevalences (proportions of donors with specific IgG levels above the negative cut-off) and their 95% confidence intervals (error bars) of merozoite-specific IgG in plasma of individual children with acute P. falciparum malaria. B: Levels of merozoite antigen-specific IgG in plasma, expressed as fold arbitrary units (AU) of the negative cut-off AU value for each antigen (indicated by the shaded area). Medians (center lines), central 50% (boxes), central 80% (bars), and outliers (dots) are indicated. C: Proportion of IgG-positive donors with detectable IgG subclass response to PfRH5 (left), CyRPA (center), and Pf113 (right). Proportions and corresponding 95% confidence intervals of IgG1 (white), IgG2 (black), IgG3 (gray), and IgG4 (dark gray) are shown. The presented data is from one experiment.</p

Patient characteristics and laboratory data at baseline.

<p>Values reported as median (minimum-maximum) and comparisons made using Wilcoxon sign rank test. Antibody levels are expressed as mean fluorescence intensity (MFI). #ICAM-1 levels were statistically significantly higher in CM than in UM (p = 0.0037).</p><p>Anti-VSA (CD36-binding) levels were statistically significantly higher in CM than in UM (p = 0.048).</p