New evidence for intrinsic blood coagulation in chickens

[Vergleichende Bestimmung von Gerinnungsparametern in Blutproben verschiedener Wild- und Ziervogelspezies]

OBJECTIVE

Information about the influence of species variety or diseases on coagulation values in avian blood is rare. The aim of this study was to assess the influence of species on measurements of coagulation parameters in avian plasma samples using commercially available reagents and to investigate potential influences of selected diseases on clotting times.

MATERIAL AND METHODS

Prothrombin time (PT), activated partial thromboplastin time (aPTT) and thrombin time (TT) were measured in citrated plasma of healthy individuals collected from eight different wild and captive avian species applying currently commercially available reagents prepared for use in humans, which were preselected in preliminary studies. The same parameters were tested in plasma samples from birds affected by aspergillosis, atherosclerosis, neoplasia and traumata.

RESULTS

PT and aPTT showed a high interspecies variety. Irrespective of species, aPTTs were extremely long and partially exceeded the measurement range limit. Minor variations between species were seen in TT measurements. Clotting times obtained from birds affected by aspergillosis, atherosclerosis and neoplasia were not significantly different when compared to healthy birds. Plasma obtained from traumatised individuals showed significantly shorter PT and aPTT than that in healthy birds.

CONCLUSION AND CLINICAL RELEVANCE

Differences between species must be considered in diagnostic coagulation measurements in avian blood. Regardless of the avian species, aPTT measurements on avian samples appear to be of limited value. Lower PT and aPTT values reflect coagulation activation in traumatised birds.

A hundred years of cascading - started by Paul Morawitz (1879-1936), a pioneer of haemostasis and of transfusion

Morawitz is mainly remembered for clarifying the role of prothrombin in clotting, but his mature years saw him guide advances in transfusion therapy. He was among the first to describe haemolytic transfusion reactions and to advocate using blood anticoagulated by citrate. He was a talented organiser - founding the Leipzig Donor Centre during increasingly difficult economic and political times. An excellent general physician, his interest in clotting led to clinical work in thrombosis and angina, and the use of quinidine for cardiac dysfunction. Ironically he died of acute myocardial infarction two years after his first attack of angina and coronary thrombosis.

Turkey intestine as a commercial source of heparin? Comparative structural studies of intestinal avian and mammalian glycosaminoglycans

Heparin is a glycosaminoglycan (GAG) that is extracted primarily from porcine intestinal tissues and is widely used as a clinical anticoagulant. It is biosynthesized as a proteoglycan and stored exclusively in mast cells and is partially degraded to peptidoglycan and GAG on immunologically activated mast cell degranulation. In contrast, the structurally related heparan sulfate, is the polysaccharide portion of a ubiquitous proteoglycan, localized on cell surface and in the extracellular matrix of all animal tissues. Heparin and heparan sulfate are made in the Golgi through a similar biosynthetic pathway. The current study was undertaken in a search for alternative, non-mammalian, sources of anticoagulant heparin. The heparin/heparan sulfate family of GAGs, prepared and purified from turkey intestine, were assayed for anticoagulant activity and structurally characterized. The resulting GAGs displayed a very low anticoagulant activity when compared to those obtained from porcine intestine using an identical procedure. Structural characterization studies clearly demonstrate that heparan sulfate is the major GAG in the turkey intestine. This observation is rationalized based on differences in the mammalian and avian coagulation and immune systems.

Immunologic studies of factor VIII coagulant activity (VIII:C). 2. Factor VIII in selected vertebrates

Cross reactive antigens to factor VIII have been measured in a range of vertebrate phyla. VIII coagulant antigen (VIII:CAg) measured using a human antibody was in general, much lower than reported values of VIII coagulant activity (VIII:C) except in simians and the guinea pig. The dose response curve for the assay was parallel in all cases. Factor VIII-related antigen (VIIIR:Ag) measured using rabbit antibody to human VIIIR:Ag was low or absent in most species except simians and the dose response curve was non-parallel to the human standard except with goat plasma. Avians lacked cross-reactive material.