Blood Platelets Cause Retraction of Collagen Gel

Human blood platelets cause the collagen gel retraction (CGR) with concomitant exclusion of fluid. CGR is positively related to the number of incorporated platelets and inversely to collagen concentration. Disruption of platelets, EDTA and cytochalasin B inhibit CGR. Platelets from patients with Glanzmann's thrombasthenia are active in CGR. The similarities and differences of CGR and fibrin retraction are discussed.

Hemorrhagic Parapneumonic Effusion in a 64 Year-Old Patient as the First Symptom of Hemophilia B

Hemophilia B is an inherited, X chromosome-linked disease. It is usually diagnosed in childhood, sometimes in adolescence. The commonest symptoms include spontaneous or post-traumatic bleeding into the joints and/or muscles, as well as mucosal bleeding. Respiratory symptoms are rarely reported. We present the case of a 64 year-old man in whom bloody parapneumonic effusion (hemothorax) was the first symptom of hemophilia B. The reason for prolonged activated partial thromboplastin time (APTT) found on admission has not been elucidated. Since antibiotic therapy and pleural tube thoracostomy with intrapleural streptokinase were found to be ineffective, video-assisted thoracic surgery was performed with the right lung decortication. Post-operative treatment was complicated by massive pleural bleeding requiring two subsequent thoracotomies. Additional blood tests revealed factor IX deficiency and resulted in hemophilia B being diagnosed. The presented case proves that hereditary bleeding disorders may be diagnosed even in late adulthood. Intrapleural bleeding related to pneumonia and pleural inflammation might be the first presenting symptom. Hemophilia should be considered as a potential cause of APTT prolongation, even in an elderly patient with atypical presentation. Explaining the reason for APTT prolongation before the surgical procedure could have allowed to avoid severe bleeding in the described patient.

[Hemorrhagic parapneumonic effusion in a 64 year-old patient as the first symptom of hemophilia B]

Hemophilia B is an inherited, X chromosome-linked disease. It is usually diagnosed in childhood, sometimes in adolescence. The commonest symptoms include spontaneous or post-traumatic bleeding into the joints and/or muscles, as well as mucosal bleeding. Respiratory symptoms are rarely reported. We present the case of a 64 year-old man in whom bloody parapneumonic effusion (hemothorax) was the first symptom of hemophilia B. The reason for prolonged activated partial thromboplastin time (APTT) found on admission has not been elucidated. Since antibiotic therapy and pleural tube thoracostomy with intrapleural streptokinase were found to be ineffective, video-assisted thoracic surgery was performed with the right lung decortication. Post-operative treatment was complicated by massive pleural bleeding requiring two subsequent thoracotomies. Additional blood tests revealed factor IX deficiency and resulted in hemophilia B being diagnosed. The presented case proves that hereditary bleeding disorders may be diagnosed even in late adulthood. Intrapleural bleeding related to pneumonia and pleural inflammation might be the first presenting symptom. Hemophilia should be considered as a potential cause of APTT prolongation, even in an elderly patient with atypical presentation. Explaining the reason for APTT prolongation before the surgical procedure could have allowed to avoid severe bleeding in the described patient.

Fibrinogen does not protect von Willebrand factor against proteolysis by human cathepsin G

The susceptibility of von Willebrand factor /vWF/ to digestion by human neutrophil cathepsin G in highly purified FVIII/vWF concentrate /BHS/ and in cryoprecipitate has been studied. In contrast to human neutrophil elastase, cathepsin G inactivates and degrades vWF not only in BHS but also in cryoprecipitate. Fibrinogen added in excess to purified FVIII/vWF concentrate does not protect vWF against cathepsin G proteolysis. Biological significance of this phenomena are discussed.

Effects of human elastase on von Willebrand factor in highly purified factor VIII concentrate and in cryoprecipitate

The susceptibility of v. Willebrand factor (vWF) and F.VIII in virus-inactivated factor VIII/vWF concentrate (Behring-Haemate-HS (BHS] and in cryoprecipitate (Behring-Ristofact) to digestion by highly purified, cathepsin G free human neutrophil elastase (HNE) was compared. In Haemate-HS HNE induced a degradation of the vWF subunit. This reaction was dependent on time and enzyme concentration. It resulted in disappearance of large size vWF multimers, an anodal shift of vWF peak in crossed immunoelectrophoresis and a decrease of F.VIII:C and Ristocetin cofactor activities. In contrast in cryoprecipitate even high HNE concentration did not provoke changes of these parameters. Both Haemate-HS and Ristofact were free of alpha 1-proteinase inhibitor (alpha 1 PI) and alpha 2-macroglobulin (alpha 2 M) but they differed in the content of other contaminating proteins. In particular Haemate-HS was fibrinogen-free but Ristofact contained 6.6 mg/ml. Purified fibrinogen added to Haemate-HS was found highly effective in protecting vWF in Haemate-HS against the proteolytic degradation and loss of activity under the influence of HNE.

Blood platelets cause retraction of collagen gel

Human blood platelets cause the collagen gel retraction (CGR) with concomitant exclusion of fluid. CGR is positively related to the number of incorporated platelets and inversely to collagen concentration. Disruption of platelets, EDTA and cytochalasin B inhibit CGR. Platelets from patients with Glanzmann's thrombasthenia are active in CGR. The similarities and differences of CGR and fibrin retraction are discussed.