Diminished recognition of Galα-terminated glycan epitopes and reduced Galα-dependent xenogeneic anti-porcine reactivity of CVID and symptomatic IgGSD sera. (A) IgG antibody reactivity to Galili, αLN, and Aα3GN glycans, as assessed by suspension array (multiplex immunoassay). Individual sera from HDs (n = 18) or from HGG (n = 37), CVID (n = 15), and IgGSD (n = 8) patients were analyzed. Box-and-whisker diagrams were created by the Tukey method. The middle line is plotted at the median, and the box represents the interquartile range (difference between the 25th and 75th percentiles). Significant values are reported (Kruskal-Wallis test). (B) Reduced surface staining of anti-Galili monoclonal antibody reactivity following α-galactosidase treatment of porcine PK15 cells, as assessed by flow cytometry. Representative line graph (left panel) and summary (right panel). Student t test was used to calculate the P values. (C) ADCC activity of primary human NK cells against PK15 cells at an effector-to-target ratio of 10:1, in the absence or presence of α-galactosidase (n ≥ 3). Significant values are reported (Student t test). (D) Histopathologic analysis of pig skin damage in cryosections incubated with healthy and patient sera in the presence of healthy human leukocytes. Representative examples for each analyzed disease and control are shown (left panels and lower right panel; hematoxylin and eosin stain). The dashed lines indicate the dermal–epidermal junction. Scale bars, 75 µm. The damage induced was calculated as the dermal–epidermal separation (DES) normalized to the IgG concentration in the sera (upper right panel) (n ≥ 7). Significant values are reported (Kruskal-Wallis test). N.S., not significant; PBS, phosphate-buffered saline.