Evidence of fibrinogenolysis and fibrinolysis in AOC. (A) A representative western blot run under nonreducing conditions using an anti-human fibrinogen detection antibody of samples from patients with AOC (red) and severe PPH without AOC (blue); the nonbleeding pregnant control sample (green) was taken before an elective cesarean delivery. Fragment D indicated is a specific marker of fibrinogen proteolysis; fragment Y is ∼160 kDa. (B) A reducing western blot with samples as in panel A, with breakdown products less than ∼30 kDa are detected in AOC but not in PPH without AOC. (C) A representative nonreducing gel of sequential samples over time from a single patient with AOC, revealing fibrinogen in the earliest sample on the left and the latest on the right. A confocal microscopy image of the plasma fibrin clot at the earliest time point (lane 3) is illustrated. (D) D-dimer levels in nonbleeding pregnant controls, AOC, and severe PPH without AOC. (E) Representative confocal microscopy images of plasma fibrin clots for pooled normal plasma (PNP), nonbleeding pregnant control taken before an elective cesarean delivery (control) PPH without AOC (PPH non-AOC), and a case of AOC (AOC). (F) The relationship between Clauss fibrinogen and INTEM A5, as a measure of clot strength, performed on a ROTEM Sigma device. Blue dots are cases of AOC and grey dots of PPH without AOC; individual cases might contribute more than 1 data point. There was no difference in clot firmness, as measured by ROTEM, between the AOC and PPH without AOC groups at similar Clauss fibrinogen levels. Dashed line is the linear correlation for all non-AOC cases (R2 = 0.24), and the solid line is the linear correlation for all AOC cases (r2 = 0.63).
