Figure 1: (a) Viral kinetics: a slight decrease in serum HCV RNA values was observed during the lead-in phase. Soon after the introduction of boceprevir (week 4), a drastic reduction in viremia was observed, with complete negativization at week 5. The vertical dashed line represents the introduction of boceprevir; the horizontal continuous line indicates the detection limit of the HCV RNA test (15 IU/mL). IU: international units; mL: milliliter; w: week; f. up: follow up; m: month. (B) Cryocrit C4 and RF kinetics during the combined therapy (RTX+Peg-IFN+RBV+BOC). The time points considered are (1) before rituximab (June 2011), (2) two months after rituximab cycle (September 2011; triple therapy baseline), and (3) end of the follow-up after boceprevir-based antiviral therapy (November 2013). After RTX therapy cryocrit, C4 and RF normalized and remained persistently normal. (●) Cryocrit; (■) rheumatoid factor; (▲) C4. RF: rheumatoid factor; normal values: <10 IU/mL; normal values of C4: from 10 to 40 mg/dL.