Charles F. Abildgaard

Prevalence of Oropharyngeal Excreters of Leukocyte-Transforming Agents among a Human Population

Abstract For better understanding of the epidemiology of leukocyte-transforming agent recently demonstrated in the oropharyngeal secretions of patients with infectious mononucleosis, a population was surveyed for excreters of this agent. The agent was identified by its ability to transform human leukocytes into rapidly and persistently multiplying lymphoid cells. Eighteen per cent of 368 general outpatient-department patients were found to be excreters. No significant differences in prevalence were noted among age groups, between sexes, among five broad medical-status categories, and between patients studied in June and December, 1972. This transforming agent appears to be a ubiquitous infectious agent of man. In addition to the patients studied in our general outpatient clinic, 69 with cancer were surveyed for excretion of this agent. Among adults with leukemia or lymphoma, all seven critically ill patients and 11 of 12 on intensive chemotherapy excreted this agent. There is no known basis for the preval...

STUDIES ON THROMBOPOIESIS. II. ASSAY OF HUMAN PLASMA THROMBOPOIETIC ACTIVITY.

An extract of fresh normal human plasma was shown to contain a factor capable of inducing platelet formation in rats. This thrombopoietic factor, which is labile on storage, was markedly deficient in the plasma of a child with chronic congenital thrombocytopenic purpura who responded repeatedly to infusions of normal human plasma. Plasmas of children with acquired idiopathic thrombocytic purpura (ITP) contained normal amounts of thrombopoietic factor. However, 10 of 20 children with acute ITP responded to infusions of large amounts of normal human plasma, thus suggesting that platelet formation in man may be stimulated by excesses of the thrombopoietic factor.

The Factor VIII Abnormality in Severe von Willebrand's Disease

We attempted to characterize the small amounts of factor VIII-related antigen detectable in the severe recessive form of von Willebrands disease with newly developed radioimmunoprecipitin techniques and radiocrossed immunoelectrophoresis. Previous studies have failed to demonstrate factor VIII-related antigen in most patients tested even with the highly sensitive immunoradiometric assays. Using the newer techniques, we found antigen in the plasma of six of eight patients with severe von Willebrands disease from different kindreds. Qualitative abnormalities of the trace quantities of factor VIII-related antigen were demonstrated in five of the patients, with absence or relative decrease of the larger, less anodal forms. In addition, five distinct patterns were observed, each suggesting a different molecular abnormality. Heterozygous parents had normal to moderately decreased factor VIII-related antigen, with normal crossed immunoelectrophoretic patterns. This study suggests that severe von Willebrands disease is a heterogeneous syndrome with various underlying molecular defects.

Factor-VIII (Antihaemophilic Factor) Activity in Sickle-Cell Anaemia.

Sickle‐cell anaemia was found to be associated with elevated Factor‐VIII activity in the absence of significant elevation of other coagulation factors. Factor VIII was normal in individuals with sickle‐cell trait except during pregnancy. Following multiple transfusions Factor‐VIII levels fell to within the normal range in three patients with sickle‐cell anaemia. No relationship between Factor‐VIII level and painful crisis was noted. It is suggested that the elevation of Factor VIII is directly related to the degree of haemolysis.

ABSENCE OF COAGULATION ABNORMALITIES IN CHILDREN WITH CYANOTIC CONGENITAL HEART-DISEASE

Abstract It has been suggested that the thrombo-cytopenia often observed in cyanotic heart-disease may result from intravascular clotting, and heparin therapy has been recommended. However, coagulation data for ten cyanotic children with thrombocytopenia contained no evidence of the complex of coagulation abnormalities which are characteristic of intravascular clotting. The findings do not suggest that the thrombocytopenia observed in cyanotic congenital heart-disease results in intravascular coagulation nor do they support the therapeutic use of heparin in its management.

The in vivo Longevity of Antihaemophilic Factor (Factor VIII)

RECENT studies have demonstrated that a commercially available fraction of human plasma, prepared as fraction I of Cohn, is a potent source of antihaemophilic factor (AHF, Factor VIII) for clinical use (Surgenor, McMillan, Diamond and Steel, 1960; McMillan, Diamond and Surgenor, 1961 ; Shulman, Marder and Hiller, 1962). Because this fraction contains only one-seventh of the protein content of whole plasma, relatively large amounts can be transfused safely without significant expansion of the plasma volume, a limiting factor in the use of whole plasma. AHF levels approaching normal can be readily achieved in the haemophilic patient by the use of fraction I, whch is impossible with whole plasma. To establish a rational basis for the therapeutic use of fraction I the in vivo longevity of AHF from this source was compared with that of AHF in whole plasma.

Generalized Shwartzman Reaction: Role of the Granulocyte in Intravascular Coagulation and Renal Cortical Necrosis

The protective effect of nitrogen mustard‐induced neutropenia on the development of the GSR was studied. No coagulation defect was found in neutropenic rabbits and simultaneous administration of Thorotrast and endotoxin did not produce intravascular coagulation or renal cortical necrosis. Infusion of neutropenic rabbits with suspensions of viable granulocytes derived from peritoneal exudates reinduced susceptibility to both intravascular coagulation and renal cortical necrosis. It is concluded that the presence of granulocytes is essential for the production of intravascular coagulation by endotoxin.

Quantitative Aspects of Blood Coagulation in the Generalized Shwartzman Reaction: 1. Effects of Variation of Preparative and Provocative Doses of E. Coli Endotoxin

Extract: The generalized Shwartzman reaction (GSR) is induced in rabbits by two properly spaced intravenous injections of bacterial endotoxin and is characterized by the occurrence of bilateral renal cortical necrosis. This report describes the quantitative changes in the coagulation mechanism in response to variation of preparative and provocative doses of E. coli endotoxin and of the interval between injections. It also correlates the coagulation changes with the pathologic findings of renal cortical necrosis.Renal cortical necrosis was induced in 34 of 49 (70 %) of rabbits using 0.100 mg/kg of endotoxin as the preparative (first) injection and 0.200 mg/kg 24 hours later as the provocative (second) dose. Four hours after the preparative injection white blood cells and platelets fell significantly while fibrinogen, prothrombin time, and Factors V and VIII fell slightly. At 24 hours all determinants except the platelets had recovered and the white cells, Factor V and fibrinogen had risen to significantly higher levels than baseline. Following the second (provocative) injection of endotoxin, a precipitous fall in all factors occurred. Maximal changes developed two hours after the second injection for white cells and platelets and by four hours for the coagulation factors; at this time kidneys show fibrin. By 48 hours all factors except the platelets had returned to 24 hour levels (table I). Rabbits given 0.100 mg/kg of endotoxin and normal saline 24 hours later did not develop cortical necrosis of kidneys or reduction in levels of any of the coagulation factors or platelets (table II).With 0.1 mg/kg of endotoxin as the preparative dose, the effect of variation in the provocative dose at 24 hours was studied. With 0.2, 0.1, 0.05 mg/kg provocation renal cortical necrosis was observed in 60-100 % of animals. Rabbits given 0.01 mg/kg of endotoxin, or saline, as the second injection did not develop the GSR. Coagulation changes were measured four hours after the provocative injections. With doses of endotoxin of 0.025 mg/kg and greater there was a significant fall in white cells, platelets and each of the coagulation factors measured. With 0.01 mg/kg there was a significant decrease in Factors II, V and VIII but no significant fall in white cells, platelets or fibrinogen. With saline all of the measured factors rose (table V). Changes in fibrinogen following different provocative doses are demonstrated in fig. 5. Renal cortical necrosis did not occur until a fall in fibrinogen of 66 mg/100 ml was produced.The effect of varying the preparative dose was studied. Groups of rabbits were given either saline, 0.001 mg/kg, 0.01 mg/kg or 0.1 mg/kg endotoxin preparation and all animals received 0.1 mg/kg endotoxin 24 hours later. With saline or 0.001 mg/kg endotoxin as preparation no GSR occurred. With a 10 and 100 fold increase in concentration of endotoxin the GSR was regularly produced. With saline preparation significant changes occurred only in white cells and platelets. A significant decline in all factors except Factor VIII was produced by preparation with 0.001 mg/kg endotoxin; the fibrinogen fell 89 mg/100 ml but no animal developed renal cortical necrosis. The inadequately prepared animal appeared able to tolerate an amount of fibrinogen conversion that would, in the properly prepared animal, result in renal cortical necrosis. In rabbits prepared with 0.01 mg/kg and 0.1 mg/kg of endotoxin significant changes occurred in all factors and renal cortical necrosis was produced (table VI). Rabbits were given 0.1 mg/kg endotoxin as preparation and a dose of 0.1 mg/kg was administered at 24 hours to one group of animals and at 48 hours in a second group. In the 24 hour group the GSR occurred in 10 of 13 animals; following endotoxin at 48 hours renal cortical necrosis was not produced in any of 18 rabbits. Changes in the coagulation mechanism four hours after provocation are shown in table VII and demonstrate that the fall was similar in both groups for all factors except fibrinogen. Fibrinogen decreased 178 mg/100 ml in animals given injections 24 hours apart but there was only a 70 mg/100 ml fall in the 48 hour group. The data suggest that by 48 hours after adequate preparation the RES has recovered to the degree that clotting intermediates are removed and significant amounts of fibrin are cleared thus preventing deposition in the kidneys and cortical necrosis.The interdependence of preparative and provocative doses of endotoxin was demonstrated. A dose of 0.01 mg/kg prepared the animal for subsequent provocation with 0.1 mg/kg; 0.1 mg/kg prepared animals for subsequent provocation with as little as 0.025 mg/kg. However, the combination of 0.01 mg/kg as preparation and 0.025 mg/kg as provocation did not result in cortical necrosis of the kidneys or in a fall of any of the coagulation factors (tables VIII and IX).Conclusions: In the presence of adequate preparation provocative doses of endotoxin capable of inducing cortical necrosis of the kidneys were always associated with significant consumption of all coagulation factors measured. With inadequate preparation, produced either by decreasing the preparative dose of endotoxin or by increasing the interval between injections, significant activation of the clotting system occurred but renal cortical necrosis did not develop.Speculation: The development of the generalized Shwartzman reaction, and, by inference, Shwartzman-like human syndromes, appears to require activation of the coagulation mechanism and the development of intravascular clotting. However, the degree of clotting induced by stimuli of known potency and the degree of fibrin deposition in the tissues are critically dependent upon the prior state of preparation of the animals, probably reflecting the functional adequacy of the reticulo-endothelial system.

Early treatment of hemophilic hemarthroses withminimal dose of new factor VIII concentrate

Studies of in vivo recovery and longevity of factor VIII following infusions of a new factor VIII concentrate (Koate, Cutter Laboratories) yielded results similar to those reported using other sources of factor VIII. Of 51 episodes of early joint bleeding treated with single infusions of approximately 10 units per kilogram of factor VIII, 49 resolved without further replacement therapy. Koate is an effective source of factor VIII and early hemarthroses can be treated successfully with a single infusion of factor VIII in a dose of 10 units per kilogram.

von Willebrand's disease: A comparative studyof diagnostic tests**

The comparative diagnostic value of the Duke, Ivy, and modified Ivy bleeding times, factor VIII assay, and in vivo and in vitro platelet adhesiveness was determined in 28 patients with von Willebrands disease. The combination of Duke and modified Ivy bleeding times plus factor VIII assay was adequate to detect an abnormality in all patients studied. Variability of the bleeding times and factor VIII level in some patients may make repeated testing necessary. Presently available tests of platelet adhesiveness may be abnormal in patients with von Willebrands disease, but are not necessary for the diagnosis and may give false positive results.