Fibrinogen Villeurbanne II forms aggregates with albumin in plasma. (A) The patient’s fibrinogen and fibrinogen from a healthy control appeared similar when blotted under reducing and nonreducing conditions. (B) Western blot analyses of fibrinogen coimmunoprecipitation demonstrating an interaction between the patient’s fibrinogen and albumin (at 66 kDa; arrow) that was not observed in fibrinogen from a healthy control, suggesting that the mutant fibrinogen forms aggregates with albumin. IgG, immunoglobulin G.