The approximate and the numerical solutions of the multiscale model.

<p><b>A.</b> The short-term approximation (blue solid) is compared with the solution of the multiscale PDE model (black dashed). <b>B.</b> Difference between the long-term approximation and the solution of the multiscale PDE model. Parameter values, chosen from <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002959#pcbi-1002959-t002" target="_blank">Table 2</a> and <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002959#pcbi.1002959-Rong3" target="_blank">[30]</a>, are , , , , , , , , , , , , and .</p

Phases of viral decline affected by the effectiveness of therapy in blocking intracellular viral production and assembly/secretion.

<p>When therapy significantly blocks both intracellular viral production () and assembly/secretion (), the viral load decline has three phases (blue solid), with slopes , , and , respectively. The duration of the first phase () is about 0.25 days and the duration of the second phase () is about 0.88 days using the parameter values below. When , the first-phase viral decline with the slope is not visible (red dashed). When , the second-phase viral decline is not visible (black dash-dotted). Parameter values , , , , , , , , and are from <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002959#pcbi-1002959-t002" target="_blank">Table 2</a>. Because was chosen to be 0, when comparing the predicted duration of the first phase in this figure with clinical data one may want to add the length of the pharmacological delay to .</p

Comparison of viral load data with model predictions for each patient.

<p>The prediction from the standard biphasic model is shown by the red dashed line and the prediction from the long-term approximation of the full multiscale model is shown by the black solid line. In most cases the two predicted viral load decay curves overlap and cannot be distinguished. The parameter values used to generate the theoretical curves are the best fit values given in <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002959#pcbi-1002959-t001" target="_blank">Table 1</a> and <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1002959#pcbi-1002959-t002" target="_blank">2</a>, respectively. Viral rebounds occur due to drug resistance and the decay data (circles) was only fit until resistance was detected or rebound was observed. The limit of viral load detection is indicated by the black dashed line.</p

Parameter values with standard errors in parenthesis estimated by fitting the standard biphasic model to viral load data.

1<p>Corresponding to a half-life <i>t</i>_1/2 = 0.067 days.</p>2<p>Corresponding to a half-life <i>t</i>_1/2 = 1.65 days.</p

Parameter values with standard errors in parenthesis estimated by fitting the long-term approximation to viral load data and assuming , , and other fixed parameters as given in Table 2 caption.

1<p>This value is not significantly smaller than 0.</p

Parameter values with standard errors in parenthesis estimated by fitting the long-term approximation to viral load data and assuming , , , and .

1<p>This value is not significantly smaller than 0.</p