Effect of dose and brand of IVIG on complement levels in myopathic patients. (A) Two myopathic DM patients (H and L) were treated with 2 g IVIG/kg body weight for the first time. The averaged relative C3 (•) and C4 (□) concentrations were plotted. (B) C4 consumption following injection of 2 different brands of IVIG. Patient H with DM was treated sequentially, at 2 g IgG/kg body weight, twice with Sandoglobulin, once with Endobulin, and 2 more times with Sandoglobulin. The time course of the relative C4 concentrations is illustrated for the treatment with Endobulin (▪) in comparison to that averaged (± SD) from all 4 treatments with Sandoglobulin (□). (C) C3 and C4 concentrations following treatment with 1 g IVIG/kg body weight. Two previously untreated myopathic DM patients (I and K) received 4 cycles of 1g IVIG/kg body weight. The averaged relative C3 (•) and C4 (□) concentrations were plotted. Minus or plus SD are shown for 4 to 8 determinations.