Studies of the Effects of Estradiol, Progesterone, Cortisol, Thrombophlebitis, and Typhoid Vaccine on Synthesis and Catabolism of Antithrombin III in the Dog

Proteomic study on the lymphocytes from pregnant Wistar rat females treated with immunosuppressive regimen

Kidney transplantation remains the therapeutic option for patients with end-stage kidney disease. Current immunosuppressive regimens are efficient in combating acute kidney rejection. However, insights into chronic kidney allograft injury remains limited. Simultaneously, pregnancy is more common after kidney transplantation than during dialysis treatment. Due to ethical issues, comprehensive studies on the impact of immunosuppressive regimens on pregnancy are challenging. The study aimed to investigate the proteomic status of lymphocytes obtained from pregnant female rats under immunosuppressive treatment. The experiment involved a group of 10 female, pregnant Wistar rats, five of which were treated with tacrolimus, mofetil mycophenolate, and glucocorticosteroids; five were used as control. The lymphocytes were obtained and analyzed with mass spectrometry. Measurements were processed by a database search in the ProteinPilot software with a cutoff of 1% false discovery rate. The outcomes were verified statistically by a t-test (p value < 0.05) regarding proteins up- and downregulation. A total of 2082 proteins were identified in all experiments. Eight hundred five proteins were quantified in an absolute manner in a data-independent acquisition-total protein approach analysis. Ninety-five proteins were recognized as present at different concentrations in analyzed groups and were annotated to intracellular pathways. The proteins involved in nonsense-mediated decay and L13a-mediated translational silencing of ceruloplasmin expression were recognized as downregulated. The set of proteins clinically identified as acute phase proteins was upregulated. Despite the blockade of adaptive cellular immunity, the lymphocytes in the analyzed group reveal sustained proinflammatory status with decreased ability to regulate translation. This potentially affects pregnancy and immunity.

Syndromes of thrombosis and hypercoagulability. Congenital and acquired causes of thrombosis

Blood coagulation protein and platelet defects are now known to account for up to ninety percent of unexplained venous thrombosis and up to seventy percent of unexplained arterial thrombotic or ischemic events. This article summarizes the common and uncommon blood protein and platelet defects which should be suspected, and searched for, in patients with such events. Defining such defects will have major impact on secondary prevention and duration of antithrombotic therapy in the afflicted patient and impact on primary prevention for identified family members in those harboring hereditary defects.

Hypercoagulability and thrombosis

This article has stressed the common hereditary and acquired blood protein defects associated with thrombosis. The commonest hereditary defects appear to be antithrombin, protein C, and protein S deficiency, and the commonest acquired defects are anticardiolipin antibodies and the lupus anticoagulant. Therefore these are the defects that should first be looked for in an individual with unexplained thrombosis. If these commoner defects are not found, the rarer defects, including HC-II, plasminogen or t-PA deficiency, dysfibrinogenemia, or elevated PAI-1, should next be sought. The incidence of activated protein C cofactor deficiency is not yet clear but may also represent a common defect. Likewise, PAI-1 defects may, with time, be shown to be quite common. The importance of finding these defects has significant implications for therapy of the individual patient and for institution of family studies to identify, inform, and possibly treat others at risk. It is expected that as knowledge of hemostasis expands, more hereditary and acquired defects, such as elevated lipoprotein (a) or defects of extrinsic (tissue factor) pathway inhibitor may be associated with enhanced risks of thrombosis.

Risk factors for thrombosis in lupus patients

Lupus anticoagulant, concentrations of anticardiolipin antibodies, antithrombin III, plasminogen, (free) protein S, protein C, prothrombin, platelet counts, and bleeding times were determined in 74 lupus patients (58 with systemic lupus erythematosus; 16 with lupus-like disease) to establish the presence of risk factors for thrombosis in these patients. Of the variables evaluated, lupus anticoagulant had the strongest association with a history of thrombosis. Both positive anticardiolipin antibody concentrations and the presence of (mild) thrombocytopenia were significantly associated with a history of thrombosis and the presence of lupus anticoagulant. Reduced concentrations of antithrombin III, plasminogen, (free) protein S, and protein C were found in some patients but were not associated with either thrombosis or lupus anticoagulant. Mean concentrations of total protein S were significantly lower in patients with thrombosis than in those without and in patients with lupus anticoagulant than in those without. The antigenic concentration of prothrombin was reduced in 3/74 (4%) lupus patients. These three patients had lupus anticoagulant but no history of thrombosis, which suggests that a low prothrombin concentration protects patients with lupus anticoagulant from the development of thrombosis. A prolonged bleeding time was associated with the presence of lupus anticoagulant but not with a history of thrombosis. Analysis by stepwise logistic regression did not disclose additional risk factors for thrombosis in lupus patients with lupus anticoagulant. Increased antithrombin III concentrations and decreased free protein S concentrations are often found in lupus patients, unrelated to lupus anticoagulant or thrombosis.

Pathophysiology of antithrombin III deficiency

This article focuses on the pathophysiology of thrombosis in patients with acquired antithrombin III deficiency. Antithrombin III is an important natural inhibitor of the hemostatic mechanism, and a hypercoagulable state is often induced in diseases causing antithrombin III deficiency. Laboratory determination of antithrombin III activity is particularly useful in the clinical evaluation and therapeutic management of patients with disseminated intravascular coagulation, nephrotic syndrome, and severe hepatopathy.

Evidence that chicken antithrombin III is a developmentally regulated glycoprotein synthesized by hepatocytes

Antithrombin III is the principal circulating active-site inhibitor of thrombin and other serine proteinases. We studied a protein synthesized and secreted by cultured chick embryo hepatocytes that has very similar immunological, structural and functional properties to adult antithrombin III. Its presence was demonstrated by; immunodiffusion analysis of a 100-fold concentrate of culture medium, which produced a single precipitin line of identity with adult and 1-day-old hatchling plasma antithrombin III; immunoprecipitation of a metabolically labelled protein from culture medium, having the same molecular size as adult chicken antithrombin III; conversion of antithrombin activity in culture medium to a faster acting thrombin inhibitory activity in the presence of heparin. Antithrombin III antigen levels were increased 3- to 4-fold in the presence of dexamethasone (2 nM) during a 3-day culture period. Plasma antithrombin III antigen levels from unhatched chicks increased from 26 +/- 6 micrograms/ml at 16 days of development to 104 /+- 6 micrograms/ml at 20 days, whereas 1-day-old hatchlings (21 days) had levels similar to that in adults (135 +/- 7 micrograms/ml vs. 143 +/- 24 micrograms/ml). In contrast to immunodiffusion and immunoelectrophoretic analysis of hepatocyte or hatchling plasma antithrombin III, which showed lines of identity with adult antithrombin III, 16- and 20-day-old embryonic plasma antithrombin III yielded lines of partial identity and migrated less anodally than adult antithrombin III. Consistent with this finding, embryonic plasma antithrombin III had no sialic acid (less than 0.01 residue/mol) in contrast with the adult form (3.5 residues/mol). These studies show that the increase in adult antigen levels and sialation of antithrombin III occurs rapidly after hatchling, suggesting developmental changes in expression at the transcriptional and translational levels in addition to post-translational carbohydrate processing.

Effect of thrombin and endotoxin on the in vivo metabolism of antithrombin III (AT III) in dogs

Effect of thrombin and endotoxin on the metabolism of I-125-labelled canine AT III was studied in mongrel dogs. Under control condition, mean total amount of intravascular AT III with standard deviation was 23.4 +/- 2.4 mg/kg, plasma half life of i.v. injected I-125-AT III was 1.7 +/- 0.2 days, and the fractional catabolic flux (j3x) was 16.3 +/- 1.6 mg/kg/day. The total amount of intra- and extra-vascular AT III was 36.0 +/- 0.34 mg/kg. Neither a 3 hour infusion of a small dose (30 units/kg/hr) of thrombin nor i.v. injection of a large amount of thrombin (5,000-15,000 units/day) with heparin significantly affected AT III metabolism except for a transient decrease in AT III concentration in the latter case, although decrease in plasma fibrinogen concentration and platelet count was observed in both cases. Two injections with 200 micrograms/kg of endotoxin resulted in an evident acceleration of AT III metabolism with significant decrease in the plasma AT III, fibrinogen concentrations and platelet count. More marked changes in AT III metabolism were induced by a single infusion with 1 mg/kg of endotoxin. Changes in hemostatic system coincided with those observed in DIC.

Estrogen-induced deficiency and decrease in antithrombin III activity in patients with prostatic cancer

Plasma antithrombin III activity was studied in 22 patients with prostatic cancer who were on estrogen therapy. Normal plasma antithrombin III activity varies between 0.80 and 1.40 U. per ml. A loading dose of 15 mg. diethylstilbestrol daily resulted in a marked decrease in plasma antithrombin III activity (mean 0.24 U. per ml.). Patients with the lower end of normal range of pre-treatment plasma antithrombin III activity may suffer acquired antithrombin III deficiency and, thus, a concomitantly increased risk of thromboembolic complications as a result of estrogen treatment. Patients on maintenance therapy of approximately 1 mg. daily appear to have normal plasma antithrombin III levels. The results obtained suggest that plasma antithrombin III activity should be monitored before and during estrogen therapy in patients with prostatic cancer.

Synthesis of antithrombin III and alpha-1-antitrypsin by the perfused rat liver

Livers isolated from control or turpentine-injected rats were perfused for 3 h with human red cells suspended in Krebs-Henseleit solution containing bovine serum albumin, dextran, glucose, heparin, cortisol, insulin, a mixture of 20 amino acids and [3H]leucine. Changes in the concentrations of antithrombin III and alpha-1-antitrypsin were evaluated by rocket immunoelectrophoresis using specific antisera, and incorporation of the 3H radioactivity into the total protein, albumin, antitrhombin III and alpha-1-antitrypsin in the perfusate was measured. The results indicate that both antithrombin III and alpha-1-antitrypsin are synthesized in the liver. Local inflammation induced in the liver donors moderately stimulated the synthesis of alpha-1-antitrypsin but it affected only marginally that of antithrombin III.