Protein arrays were preincubated in 4 mL Superblock (Pierce) plus 2% bovine serum albumen (BSA) at 4°C overnight. Slides were assembled with 4-well modules and incubated with plasma (300 uL diluted in phosphate buffered saline [PBS] plus 2% BSA) for 1 hour at room temperature. Slides were washed with prewarmed (42°C) PBS Tween-20 (PBST) and incubated with secondary Cy3labeled antihuman IgG or IgA antibody (1:2000; Sigma and Jackson, respectively) diluted in PBS plus 2% BSA for 1 hour at room temperature. Slides were then washed 23 with prewarmed PBST, 13 with prewarmed distilled water, dried, scanned, and analyzed with GenePix Pro software (Molecular Devices).