Figure 1. CD56^pos NK cell levels pre-infection in the IDU population.

Flow cytometric analysis demonstrated that exposure to HCV did not result in altered total CD56^pos lymphocyte levels (A). However, the lymphocyte subset distribution within the overall CD56^pos population was altered in the patient group which subsequently became infected demonstrating lower levels of CD56^low mature effector NK cells compared to those that remained uninfected (B). The flow plots shown in panel C demonstrate that total CD56^pos cells can be divided into NK and NT cell subsets based on their expression of CD3. NK cell subsets are further characterized by the intensity of CD56 expression.