Trough serum immunoglobulin G (IgG) concentrations in clinically stable patients for whom comparable data were available. Each value shown is the mean for at least three determinations. Concentrations for a patient on immune globulin intravenous (IGIV) therapy are shown on the left, connected to the value for same patient on subcutaneous therapy, shown on the right. Patient numbers are shown in the box so that their infusion characteristics can be identified in Table 3 or Table 4. Overall, the mean trough IgG concentration for patients on subcutaneous therapy was 116.9% of that for patients on IV therapy.