The pathogenesis of hemophilia; an experimental analysis of the anticephalin hypothesis in hemophilic dogs

Our plain-English summary of The pathogenesis of hemophilia; an experimental analysis of the anticephalin hypothesis in hemophilic dogs, by J.B. Graham, E.M. Barrow (The Journal of Experimental Medicine, 1957).

The study

• Authors: J.B. Graham, E.M. Barrow
• Journal: The Journal of Experimental Medicine
• Published: 1957;106(2):273-92
• Cited by: 35 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

It has been possible to duplicate in the hemophilic dog four of the major experiments which have suggested in humans an "anticephalin" hypothesis for the pathogenesis of hemophilia. The experiments in the dog have been considerably extended, as compared with the human experiments, by a variety of techniques. I. Asbestos was placed in contact with hemophilic dog plasma, and the clotting time became shorter. When transfused, this plasma had no effect on the defective prothrombin utilization of hemophilic dogs, in contrast to untreated normal plasma. II. The ionic strength of native dog plasma and dog plasma citrated (38 per cent sodium citrate) then recalcified (0.2 M CaCl(2)) were calculated. The ionic strength of the native plasma was approximately 0.15 while that of the citrated plasma was approximately 0.21. Conductivity and freezing point determinations on the plasmas described above were consistent with the idea that the ionic strength of the citrated plasma was significantly higher. The biphasic dilution curve, to which much significance has been attached in arriving at the "anticephalin" hypothesis, can be produced readily in the dog. Diluting dog plasma with "iso-ionic" or "hyper-ionic" NaCl solution abolished the biphasic phenomenon. Dilution with distilled water exaggerated the biphasic curve. These experiments suggest that the biphasic curve is an artifact of uncontrolled ionic strength. III. The prothrombin utilization rates of undiluted whole hemophilic dog blood and hemophilic dog blood diluted 1:2 with 0.85 per cent NaCl were found to be the same. IV. Ether extraction of both normal and hemophilic dog plasma removed fibrinogen and reduced somewhat the concentration of prothrombin. In treated normal plasma AHF was reduced to the level of untreated hemophilic plasma, thus producing a quasi-hemophilic plasma. Defibrination and ether extraction of both normal and hemophilic dog plasma "generated" clotting activity which shortened the clotting time of hemophilic plasma and was active in the thromboplastin generation test. The activity "generated" by defibrination and ether extraction of dog plasma was adsorbed by a BaSO(4) suspension and shown, therefore, not to be the anti-hemophilic factor (AHF). Transfusion of ether-extracted normal or hemophilic dog plasma into hemophilic dogs had no effect on the prothrombin utilization rate, unlike untreated normal plasma which had a marked effect. Thus, four of the main lines of evidence supporting the "anticephalin" hypothesis were duplicated in the dog. However, by extending the experiments it was found that all were explainable on bases other than the presence of "anticephalin." Such an hypothesis is not necessary, therefore, to explain the pathogenesis of canine hemophilia. The apparent identity of hemophilia in the two species suggests that the hypothesis is also not applicable to humans.

In plain English

This 1957 laboratory study used dogs with hereditary hemophilia to test the "anticephalin" hypothesis. That hypothesis held that hemophilia comes from too much of a clotting inhibitor, not too little of the clotting factor called antihemophilic factor (AHF). Asbestos served only as a laboratory material, and the study did not examine its health effects. The authors repeated four human experiments in dogs. Plasma from three hemophilic dogs clotted faster in the test tube after contact with asbestos fibers. Transfused back into the same dogs, it left their prothrombin utilization (how fast a clotting protein is used up) essentially unchanged. Untreated normal plasma, given later to two of the dogs, greatly accelerated it. A two-phase pattern of clotting times on dilution vanished when ionic (salt) strength was held constant or raised, and distilled water exaggerated it. In four hemophilic dogs, prothrombin use was the same in undiluted whole blood and in blood diluted 1:2 with saline. Ether-treated plasma lacked AHF activity. The authors concluded that the hypothesis was not needed to explain canine hemophilia, and they suggested it also did not apply to humans.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory experiments in normal and hemophilic dogs, including test-tube clotting tests and transfusions, repeating four earlier human experiments
• Who was studied: Normal and hemophilic dogs at the Department of Pathology, University of North Carolina, Chapel Hill. The asbestos experiment used plasma from three hemophilic dogs (Nos. 50-28, 51-02, 52-05). The whole-blood dilution experiment used four hemophilic dogs. The total number of dogs is not stated.
• Exposure: Laboratory treatments of dog plasma and blood: contact of plasma with asbestos fibers (10 mg per ml for 1 hour at room temperature; fiber type not stated), followed by auto-transfusion at 2 ml per kg body weight; dilution with saline solutions of different strengths or with distilled water; and ether extraction of plasma.
• Main results:
  • In plasma from all three hemophilic dogs, the cephalin clotting time fell after contact with asbestos (tabulated as 360 to 180, 330 to 120, and 360 to 150).
  • When the asbestos-treated plasma was transfused back into the same three hemophilic dogs, their prothrombin utilization rates were essentially unaltered.
  • When two of the same hemophilic dogs were later given untreated normal plasma, prothrombin disappearance was greatly accelerated, approaching normal.
  • The calculated ionic strength of recalcified citrated dog plasma was 0.2079, compared with 0.1522 for native plasma.
  • Native dog plasma diluted with a solution of about the same ionic strength gave a single-phase ("monophasic") dilution curve, while dilution with distilled water exaggerated the biphasic curve.
  • In four hemophilic dogs, prothrombin utilization rates were the same in undiluted whole blood and in blood diluted 1:2 with 0.85 per cent saline.
  • Ether extraction reduced the AHF activity of normal dog plasma to that of hemophilic plasma; both approached zero.
  • The clotting activity "generated" by ether extraction was removed by BaSO4, which the authors took to show that it was not AHF.
  • Ether-extracted plasma transfused into hemophilic dogs had the same negligible effect as the asbestos-treated plasma.
• The authors' conclusion: The authors concluded that an "anticephalin" hypothesis is not necessary to explain canine hemophilia. Because the disease appears identical in dogs and humans, they suggested the hypothesis is also not applicable to humans.
• Limitations the authors state:
  • Calculating plasma ionic strength from electrolyte concentrations faces serious theoretical objections.
  • The dilution experiments do not prove that variable ionic strength causes the biphasic curve.
  • No categorical answer can be given for humans, because many of the dog experiments are dangerous and have not been done in humans.
  • The action of thrombin alone on AHF was not tested.

Topics

Medical terms in this study, explained in our Lexicon: Biphasic Mesothelioma.

Related studies

• Asbestos exposure results in increased lung procoagulant activity in vivo and in vitro — K.S. Callahan, D.E. Griffith, et al. (1990)
• Asbestos fibers, plasma and inflammation — J.A. Hamilton (1983)
• Coagulation of human plasma by asbestos fibers — J.A. Hamilton, J.Y. Chan, et al. (1981)
• Pet dogs as sentinels for environmental contamination — L.C. Backer, C.B. Grindem, et al. (2001)
• Toxicologic agents of concern for search-and-rescue dogs responding to urban disasters — L.A. Murphy, S.M. Gwaltney-Brant, et al. (2003)
• Asbestos, carbon nanotubes and the pleural mesothelium: a review of the hypothesis regarding the role of long fibre retention in the parietal pleura, inflammation and mesothelioma — K. Donaldson, F.A. Murphy, et al. (2010)

Browse more research in The Journal of Experimental Medicine, or return to medical research.