Proteomic analysis of microclots from critically ill patients. (A) Trypsin-digested microclots from 3 individual ICU patients were analyzed by sequential window acquisition of all theoretical fragment ion spectra–mass spectrometry (SWATH-MS). The 20 proteins with the highest relative SWATH-MS signal intensities across all 3 patients (total) were identified and represented for each individual critically ill patient and compared against a control plasma-derived library. Representative MS/MS spectra of peptides identified by both data-dependent acquisition and SWATH are shown for fibrinogen-α chain (B), -β chain (C), and -γ chain (D). ALB, albumin; APOA1, apolipoprotein A-I; C5, complement C5; CILP2, cartilage intermediate layer protein 2; FGB, fibrinogen beta chain; FSIP2, Fibrous sheath-interacting protein 2; GSTP1, glutathione S-transferase P; HRG, histidine-rich glycoprotein; KIF4A, chromosome-associated kinesin KIF4A; IGHA1, immunoglobulin heavy constant alpha 1; ILF3, interleukin enhancer-binding factor 3; MSN, moesin; POSTN, periostin; SAA2, serum amyloid A-2 protein; SERPINA1, alpha-1-antitrypsin; TGFBI, transforming growth factor-beta–induced protein ig-h3.