biostudies-literatureMacrae FLBritish Heart FoundationWellcome Trust3468-3477https://www.ebi.ac.uk/biostudies/studies/S-EPMC8525222biostudies-literatureUnknown5(17)Fibrinogen γ' accounts for 3% to 40% of plasma fibrinogen. Earlier studies indicated that fibrinogen γ' forms altered fibrin clots under static conditions, whereas clinically, altered plasma γ' levels are associated with arterial and venous thrombosis. However, the effects of static vs flow conditions on the role of γ' throughout the pathophysiological range is unknown. This study explores the effects of γ' levels on clot formation and structure in static and flow conditions. Coagulation of plasma samples with low (n = 41; 3%), normal (n = 45; 10%), or high (n = 33; 30%) γ' levels were compared with that of purified fibrinogen mixtures with increasing ratios of γ' (3%, 10%, 30%). Clots were analyzed by confocal microscopy, permeation, turbidity, and lysis techniques. In a novel 2-step flowBlood advancesHigh fibrinogen γ' levels in patient plasma increase clot formation at arterial and venous shear.PMC8525222204951/B/16/ZRG/18/11/34036215861/Z/19/ZMacrae FLSwieringa FHeemskerk JWMAriens RASfalseHigh fibrinogen γ' levels in patient plasma increase clot formation at arterial and venous shear.Fibrinogen γ' accounts for 3% to 40% of plasma fibrinogen. Earlier studies indicated that fibrinogen γ' forms altered fibrin clots under static conditions, whereas clinically, altered plasma γ' levels are associated with arterial and venous thrombosis. However, the effects of static vs flow conditions on the role of γ' throughout the pathophysiological range is unknown. This study explores the effects of γ' levels on clot formation and structure in static and flow conditions. Coagulation of plasma samples with low (n = 41; 3%), normal (n = 45; 10%), or high (n = 33; 30%) γ' levels were compared with that of purified fibrinogen mixtures with increasing ratios of γ' (3%, 10%, 30%). Clots were analyzed by confocal microscopy, permeation, turbidity, and lysis techniques. In a novel 2-step flow2021-01-01T00:00:00Z2021 Sep2025-04-18T17:28:56.647Z2025-04-07T04:58:58.209ZS-EPMC85252223443844210.1182/bloodadvances.2020003346