Surface sialic acid is similar between IVIG products and but varies in anti-Aβ monoclonal antibodies.

<p>Measurement of the SNA-binding fraction (F_SNA+IgG) and ECL-binding fraction (F_ECL+IgG) in Octagam IVIG (OCT), Gammagard IVIG (GG), mAb 6E10, and mAb 4G8 using CFCA (A) and the On-Chip method (B,C). Two different lots of mAb 4G8 are shown as 4G8a and 4G8b. Each IgG was enzymatically untreated (black bars), 2,6 sialyltransferase treated (2,6ST, light grey bars), and neuraminidase treated (NEU, dark grey bars). Error bars indicate standard deviations (n = 2). CFCA measurements of [IgG]_{FC_SNA} did not meet either the QC or SE criteria and F_SNA+IgG and are reported as zero (indicated with asterisk *). Statistical significant differences below p < 0.14 are shown for relevant comparisons, i.e. betweendifferent treatments of the same IgG and between different IgGs with the same enzymatic treatment condition. With the exception of On-Chip SNA/ECL analysis of 6E10 (**, 0.13 < p < 0.19) and On-Chip ECL analysis of GG (***, 0.11 < p <0.13), all NEU-treated IgG differed significantly (p < 0.08) from their corresponding untreated and 2,6ST-treated forms. Other relevant statistically significant differences are indicated as follows: (a) 0.05 < p < 0.10 between untreated 6E10 and 4G8a; (b) 0.02 < p < 0.08 between 2,6ST-treated 6E10 and 4G8b; (c) 0.04 < p < 0.08 between untreated 4G8a and 4G8b; (d) 0.05 < p < 0.11 between 2,6ST-treated 4G8a and p < 0.04 between 2,6ST-treated 4G8b; (e) 0.10 < p < 0.13 between 2,6ST-treated 4G8a and untreated 4G8b; (f) 0.01 < p < 0.03 between 2,6ST-treated 4G8b; (g) 0.08 < p < 0.10 between 2,6ST-treated 4G8b; (h) p < 0.05 between untreated 6E10 and 0.10 < p < 0.13 between untreated 4G8b; (i) p < 0.003 between 2,6ST-treated 4G8b; (j) p = 0.10 between 2,6ST-treated OCT; (k) 0.07 < p 0.11 between NEU-treated 6E10, 4G8a, and 4G8b; (l) 0.06 < p < 0.08 between NEU-treated 6E10, 4G8a, and 4G8b; (m) 0.06 < p 0.08 between NEU-treated 4G8a and 4G8b; (n) p = 0.13 between NEU-treated 4G8b. Differences with p > 0.14 are not shown.