Correlation of liver stiffness and age as a surrogate marker of disease duration. Panel A shows the correlation in HIV negative patients, Panel B in HIV positive patients. The slope of the regression line is identical in both subsets (HIV pos. 0.31 ± 0.04 kPa/year; HIV neg. 0.29 ± 0.03 kPa/year). This indicates that there is no difference with regard to HCV duration between both groups.