Illustrative examples of viral reactivation patterns in individual patients treated with antibody-based immunosuppressive therapy. Dashed lines and solid lines represent separate patients. Following HC (A), EBV DNA positivity peaked at about 3 weeks, decreasing precipitously in the following weeks. Increases in EBV viral load were common in subsequent months (A). In more than half the patients who received HCS, the highest EBV viral load occurred later than 3 weeks (B). In some cases the EBV PCR remained positive for most of the course of immunosuppression with frequent fluctuations in viral load (C; HC, solid; HCS, dashed). Patients who received RC had the highest EBV copies of all 4 groups, often remaining positive for many months (D). CMV reactivation occurred more frequently after HC, and the highest CMV viral load of our cohort was in the CP arm (E; CP, solid line; HC, dashed line). HC and HCS were administered as a first course of immunosuppression, and RC and CP as a second course of immunosuppression. HC indicates horse ATG + cyclosporine; HCS, horse ATG + cyclosporine + sirolimus; RC, rabbit ATG + cyclosporine; CP, alemtuzumab.