Associated von Willebrand disease as a possible cause of lack of thrombosis in an AT III abnormality (AT III Trento)

In a family with a known antithrombin III abnormality (AT III Trento) an associated von Willebrand defect (Type I) was found. The two defects seem to segregate independently. In fact four types of individuals were present, namely: subjects with isolated AT III abnormality, subjects with isolated von Willebrand defect, patients with double defect and normal subjects. Only one of the two patients with isolated AT III abnormality showed a thrombotic tendency. None of the patients with double defect showed thrombotic disease, indicating a possible protective action of the von Willebrand defect against thrombotic manifestations. Patients with isolated von Willebrand defect showed neither thrombotic nor bleeding manifestations. The study emphasizes the need for a careful evaluation of the hemostatic balance of patients with AT III abnormalities before concluding that they are symptomatic or asymptomatic.     

Fluctuation of thrombin-antithrombin III complex in patients with acute myocardial infarction: influence of low-dose heparin administration.

The haemostatic parameters were studied within 14 days of acute myocardial infarction (AMI) in 103 patients randomly allocated into a group receiving low-dose heparin or into a group treated without anticoagulants. Patients with isotopic evidence of deep vein thrombosis were excluded from the analysis. An important formation of thrombin-antithrombin III complex (TAT) in the plasma was detected in the early stage of the disease. It was accompanied by an activation of plasma intrinsic fibrinolysis (IF), an elevation of fibrinogen and its degradation products (FDP) and a reduction of extrinsic plasma fibrinolytic activity (EF) together with normal levels of factor X, antithrombin III (AT III), protein C and alpha-2-antiplasmin. Sequentially studies periods of the disease revealed a diminution of TAT complex concentration in the plasma on the seventh day of AMI together with a rise of the both plasma fibrinolytic activities (IF, EF) as well as an elevation of fibrinogen and its degradation products, returning to the initial values on the 14 day of AMI. In the patients treated with heparin the augmentation of TAT complex in the plasma was prolonged until the fifth day of AMI. Moreover, heparin administration was connected with significantly higher levels of AT III and protein C along with a lower concentration of factor X and FDP on the seventh day of the disease. The fluctuation of fibrinolytic activities (IF, EF) in the plasma was heparin-independent. The present results indicate that low-dose heparin treatment modulates the plasmatic fluctuation of TAT complex as well as factor X, AT III and protein C levels in patients with acute myocardial infarction.     

Different effects of aging on the opioid mechanisms controlling gonadotropin and cortisol secretion in man

The present study was undertaken in order to assess the influence of aging on the endogenous opioid control of gonadotropin and adrenocorticotropin/cortisol secretion in man. For this purpose, the capability of the opioid antagonist naloxone to increase circulating levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and cortisol was tested in male subjects of different ages. Thirty normal men were randomly chosen and divided into 3 groups by age: group I = 22-40 years (n = 10); group II = 41-59 years (n = 10); group III = 62-80 years (n = 10). Since the men of group III showed higher basal serum gonadotropin concentrations than the subjects of group I and group II, we selected from a large population a fourth group of elderly men with normal basal LH and FSH levels: group IV = 61-82 years (n = 7). All subjects were tested for 120 min during the intravenous administration of naloxone (4 mg given in an intravenous bolus at time 0, plus 10 mg infused for 2 h). Control tests with normal saline instead of naloxone were performed in all groups. All subjects had similar blood testosterone and cortisol levels, whereas LH and FSH concentrations were significantly higher in group III than in groups I, II and IV. Naloxone increased plasma cortisol concentrations by 50% in all groups. The cortisol secretory response followed a similar pattern regardless of age.(ABSTRACT TRUNCATED AT 250 WORDS)     

Coagulation inhibitors and glycaemic control in non-insulin-dependent diabetes mellitus

The relationship between long-term glycaemic control and the activity of coagulation inhibitors was investigated in 60 non-insulin-dependent diabetes mellitus (NIDDM) patients not on insulin therapy. Overall, the activities of antithrombin III (AT III) (median 96%, range 65–133%), protein C (127%, 24–190%) and protein S (130%, 54–163%) were not reduced. Patients in poor long-term glycaemic control as verified by increased glycated haemoglobin (HbA1c) demonstrated significantly decreased median AT III activity in comparison with patients in good glycaemic control (92% vs 101%,P=0.016). However, individual values for AT III activity were not below the critical limit of 60%. An inverse correlation between AT III activity and long-term glycaemic control (HbA1c) was calculated (r=–0.378,P=0.0029). As AT III concentrations were found to be normal, we propose that non-enzymatic glycation leads to reduced activity of AT III without affecting its concentration.     

Thrombosis promoting changes in chronic liver diseases

Causes of haemorrhagic tendency in liver disorders have been widely studied. Deficiency of procoagulants is the best explanation for it. Not seldom a thrombotic tendency or even overt thrombosis occurs and may be satisfactorily explained. The level and function of two important natural anticoagulants, i.e. of antithrombin III and protein C is markedly reduced, first in liver cirrhosis. Heparin cofactor activity of AT III and/or heparin cofactor II may be especially diminished. The hypercoagulable state resulting from these changes may be further aggravated by a so-called hyper-adhesive state which is the consequence of the sustained high level of plasmatic vWFAg associated with liver cirrhosis. Altered haemostatic balance needs individual laboratory evaluation.     

Therapeutic plasmapheresis and haemostatic system

The influence of therapeutic plasmapheresis by using membrane filter was investigated in 38 patients with 108 procedures. Fibrinogen and AT III reached most pronounced reduced levels in the course of three plasma exchanges while factors II, V, X, Hepato-Quick, Reptilase time and thrombocyte count remained relatively unchanged. There was no bleeding or thrombotic event in the patients. We concluded that at least determination of fibrinogen and AT III levels must be done just prior to each individual plasmapheresis to prevent dangerous imbalances in haemostatic system.     

Antibodies against the activated coagulation factor X (FXa) in the antiphospholipid syndrome that interfere with the FXa inactivation by antithrombin

Antiphospholipid Ab have been shown to promote thrombosis and fetal loss in the antiphospholipid syndrome (APS). Previously, we found IgG anti-thrombin Ab in some APS patients that could interfere with inactivation of thrombin by antithrombin (AT). Considering that activated coagulation factor X (FXa) is homologous to thrombin in the catalytic domains and is also regulated primarily by AT, we hypothesized that some thrombin-reactive Ab may bind to FXa and interfere with AT inactivation of FXa. To test these hypotheses, we studied reactivity of eight patient-derived monoclonal IgG antiphospholipid Ab with FXa and the presence of IgG anti-FXa Ab in APS patients and investigated the effects of FXa-reactive mAb on AT inactivation of FXa. The results revealed that six of six thrombin-reactive IgG mAb bound to FXa and that the levels of plasma IgG anti-FXa Ab in 38 APS patients were significantly higher than those in 30 normal controls (p < 0.001). When the mean plus 3 SDs of the 30 normal controls was used as the cutoff, 5 of 38 APS patients (13.2%) had IgG anti-FXa Ab. Importantly, three of six FXa-reactive mAb significantly inhibited AT inactivation of FXa. Combined, these results indicate that anti-FXa Ab may contribute to thrombosis by interfering with the anticoagulant function of AT on FXa in some APS patients.     

Collagen synthesis by cultured skin fibroblasts from siblings with hydroxylysine-deficient collagen.

It has been previously shown that dermis from subjects with hydroxylysine-deficient collagen contains approximately 5% of normal levels of hydroxylysine and sonicates of skin fibroblasts contain less than 15% of normal levels of collagen lysyl hydroxylase activity. However, cultures of dermal fibroblasts from two siblings with hydroxylysine-deficient collagen (Ehlers-Danlos Syndrome Type VI) compared to fibroblasts from normal subjects synthesize collagen containing approximately 50% of normal amounts of hydroxylysine. The lysyl hydroxylase deficient cultures synthesize both Type I and Type III collagen in the same proportion as control cultures. Both alpha 1(I) and alpha 2 chains are similarly reduced in hydroxylysine content. Collagen prolyl hydroxylation by normal collagen lysyl hydroxylation is the same with or without ascorbate supplementation. In mutant cells the rate of prolyl hydroxylation measured after release of inhibition by alpha, alpha'-dipyridyl is the same as in control cells. The rate of lysyl hydroxylation is reduced in mutant cells but only to approximately 50% of normal.     

Increased expression of TNF-alpha,IL-6, and IL-8 in HALS: implications for reduced adiponectin expression and plasma levels

Human immunodeficiency virus (HIV)-associated lipodystrophy syndrome (HALS) is a side effect of highly active antiretroviral therapy of HIV-infected patients; however, the mechanism of the lipodystrophy and insulin resistance seen in this syndrome remains elusive. Adiponectin, an adipocyte-specific protein, is thought to play an important role in regulating insulin sensitivity. We investigated circulating levels and gene expression of adiponectin in subcutaneous abdominal adipose tissue (AT) from 18 HIV-infected patients with HALS compared with 18 HIV-infected patients without HALS. Implications of cytokines for adiponectin levels were investigated by determining circulating levels of TNF-alpha, IL-6, and IL-8 as well as gene expression of these cytokines in AT. HALS patients exhibited 40% reduced plasma adiponectin levels (P < 0.05) compared with non-HALS subjects. Correspondingly, adiponectin mRNA levels in AT were reduced by >50% (P = 0.06). HALS patients were insulin resistant, and a positive correlation was found between plasma adiponectin and insulin sensitivity (r = 0.55, P < 0.01) and percent limb fat (r = 0.61, P < 0.01). AT mRNA of TNF-alpha, IL-6, and IL-8 was increased in AT of HALS subjects (P < 0.05), and both AT TNF-alpha mRNA and plasma TNF-alpha were negatively correlated to plasma adiponectin (P < 0.05). Finally, TNF-alpha was found in vitro to inhibit human AT adiponectin mRNA by 80% (P < 0.05). In conclusion, HALS patients have reduced levels of plasma adiponectin and adiponectin mRNA in AT. Increased cytokine mRNA in AT is hypothesized to exert an inhibitory effect on adiponectin gene expression and, consequently, to play a role in the reduced plasma adiponectin levels found in HALS patients.     

Collagen synthesis by cultured skin fibroblasts from siblings with hydroxylysine-deficient collagen

It has been previously shown that dermis from subjects with hydroxylysine-deficient collagen contains approximately 5% of normal levels of hydroxylysine and sonicates of skin fibroblasts contain less than 15% of normal levels of collagen lysyl hydroxylase activity. However, cultures of dermal fibroblasts from two siblings with hydroxylysine-deficient collagen (Ehlers-Danlos Syndrome Type VI) compared to fibroblasts from normal subjects synthesize collagen containing approximately 50% of normal amounts of hydroxylysine. The lysyl hydroxylase deficient cultures synthesize both Type I and Type III collagen in the same proportion as control cultures. Both α1(I) and α2 chains are similarly reduced in hydroxylysine content. Collagen prolyl hydroxylation by normal and mutant cells is severely depressed without ascorbate but in all cultures collagen lysyl hydroxylation is the same with or without ascorbate supplementation. In mutant cells the rate of prolyl hydroxylation measured after release of inhibition by α,α′-dipyridyl is the same as in control cells. The rate of lysyl hydroxylation is reduced in mutant cells but only to approximately 50% of normal.     

On the clinical significance of acquired antithrombin deficiency

The concentration of antithrombin III (AT) was determined with a chromogenic method in plasma samples from 1,302 patients referred for evaluation of the haemostatic system. A clearly subnormal AT level (below 60%) was found in 129 patients. In ten cases, this was explained by known (8 cases) or suspected (2 newborns) hereditary deficiency. Only in 5% of the 600 cases referred with definite or suspected thrombosis, AT was below 60%. These cases had a lethality of about 20%. In about 30% of the cases with liver disease, AT was below 60%. In a group of 72 patients with either severe infection, cardiac insufficiency, malignancy or suspected DIC for other reasons, AT was below 60%. Also in this group lethality was about 50% despite lack of a clear DIC blood profile in 67 of the 72 patients. The results indicate that an AT value below 60% of normal, unexplained by hereditary deficiency, carries a grave prognosis.     

Antithrombin III Padua: a "new" congenital antithrombin III abnormality with normal or near normal activity, normal antigen, abnormal migration and no thrombotic disease

A "new" antithrombin III abnormality is described in four members of a family. The proposita is a 38 years old female who showed no thrombotic disease and the following laboratory pattern: normal routine clotting tests, normal or near normal AT III activity (chromogenic substrates S-2238 and Chromozym Th) both in plasma and in serum and in the presence or absence of heparin, slightly decreased antifactor Xa activity (chromogenic substrate S-2222), normal progressive antithrombin, normal AT III antigen but abnormal migration in the agarose-heparin bidimensional system. In the latter test, one major abnormal peak, less anodal than the normal counterpart, and a smaller, apparently normal peak, were seen. In agarose without heparin the pattern was similar to normal both in plasma and in serum. Heparin tolerance to heparin in vivo and in vitro was slightly increased but still within normal limits. The two sons and a paternal aunt showed the same pattern. The hereditary pattern seems therefore autosomal dominant. The abnormality described appears different from AT III Budapest. The toponym of antithrombin III Padua is proposed to define this peculiar abnormality.     

Antithrombin III mRNA in adult rat liver and kidney and in rat liver during development

Using Northern blots the size of antithrombin III (AT III) mRNA in rat liver was found to be 1650 nucleotides. Adult rat kidney also contained a slightly smaller mRNA at about 20% the level in liver. The ontogeny of AT III mRNA in the liver was assessed by dot blot hybridization. The mRNA was detectable at the earliest age examined (14th day of gestation) at about 15% of the adult levels. After the 17th day of gestation the levels of antithrombin III mRNA rise reaching 50% of adult levels at birth. After birth the mRNA levels rise to 75% of adult levels by the 5th day and reach adult levels by 40 days after birth. We suggest that foetal AT III is produced by both the foetal liver and by placental transfer of the maternal inhibitor.     

A tentative classification of AT III congenital abnormalities

Twenty two families with an abnormal antithrombin III have been described so far. A classification of these abnormality encounters many difficulties. In fact, the available classifications seem inadequate. On the basis of 5 tests, namely AT III progressive and/or global activity, heparin co-factor activities, crossed immunoelectrophoresis (CIE) without and with heparin, AT III antigen and heparin affinity studies, a "new" tentative classification is proposed. On the basis of these tests, AT III abnormalities may be subdivided in 5 groups: Group 1 includes asymptomatic patients with a variable defect in heparin cofactor activities with normal total or progressive AT III activity and with a slow peak in the heparin modified CIE. Group 2 comprises symptomatic patients with the same laboratory features as presented by group 1 patients. Group 3 includes families in which there is a variable reduction of all AT III activities. There is always a slow peak in the heparin modified CIE and patients are symptomatic. Group 4 includes patients with a variable decrease of all AT III activities but a normal CIE. Patients are symptomatic. Group 5 comprises symptomatic patients with variable decreased AT III activity, and with a fast moving peak in the plain (without heparin) CIE.     

Serum antibodies to native and denatured type I and III collagen in patients with periodontal disease

Serum IgG antibodies to collagen were investigated by using enzyme linked immunosorbent assay (ELISA) in patients with chronic periodontal disease. Patients with varying forms of periodontal disease including gingivitis, juvenile periodontitis, and adult periodontitis were compared with the normal subjects. The mean serum IgG levels of ELISA antibodies to native type I or III collagen in patients with juvenile periodontitis were significantly higher than those of the normal subjects, but no difference was found between the patients with either gingivitis or adult periodontitis and the normal subjects. In addition, the mean serum IgG levels of ELISA antibodies to denatured type I or III collagen in patients with juvenile or adult periodontitis were significantly higher than those of the normal subjects. These findings suggest that antibodies to native and denatured type I or III collagen may be associated with different forms or severities of periodontal disease, especially advanced periodontal destruction.     

Changes of antithrombin III (AT III) in AT III deficient patients during long-term anticoagulant treatment

Antithrombin III deficient patients with manifest thromboembolic diseases need long term coumarin treatment. There are contradictory data on the change of AT III during this therapy. The authors observed 5 patients with severe AT III decrease type I, 3 with functional abnormality and 2 with a pathological heparin binding. AT III function was determined by the Gerendás-Rák method and with chromogenic substrate. AT III antigen was measured with Behring M-Partigen and Laurell rocket electrophoresis. Crossed immunoelectrophoresis was carried out in all patients. In patients with type I AT III decrease, AT III hasn't changed even in a long period of more than 10 years. In the other types AT III became normal. The pathological heparin binding wasn't changed.     

Molecular analysis of urinary AT III related antigen in liver cirrhosis

Urinary antithrombin III (AT III) related antigen was analyzed by SDS-polyacrylamide gel electrophoresis and Western blotting, and the nitrocellulose membrane was scanned with a 2-wavelength TLC scanner. The urinary AT III related antigen was found to be located in three different molecular weight regions: the AT III region, and molecular weight regions higher and lower than that of AT III. The ratio of the higher molecular weight region to the AT III region divided by the urinary creatinine, was taken as an "index" and was analyzed in liver cirrhosis patients as well as in normal controls. The "index" in liver cirrhosis was higher than that in the controls. Further, the "index" revealed a significant proportional correlation with the total bilirubin and direct bilirubin, and also a significant inversely proportional correlation with the plasma AT III, suggesting that the "index" tends to become higher as liver function decreases. The pathophysiological significance of the "index" is briefly discussed.     

Sheep plasma protease inhibitors influencing protease activity and growth of Lucilia cuprina larvae in vitro

The enzyme inhibitors alpha 2-macroglobulin (alpha 2M), anti-thrombin III (AT III) and alpha 1-proteinase inhibitor (alpha 1PI) were isolated from sheep plasma and tested for their ability to affect L. cuprina larval proteases and larval growth in vitro. Casein radial diffusion gels indicated that both alpha 2M and alpha 1PI completely inhibited the protease activity of a larval excretory-secretory preparation, while AT III had a partial effect. Casein zymograms revealed that alpha 2M inhibited all of the larval proteases, while AT III was able to modify the normal plaque pattern; alpha 1PI inhibited all plaques except a doublet present at pI 8.5. Larval growth in vitro was significantly inhibited by alpha 2M and AT III (P less than 0.05) when compared to albumin controls but was not affected by alpha 1PI. The levels of alpha 2M in sheep serum were monitored over the course of a larval fly infection. A significant increase in alpha 2M (P less than 0.05) was recorded in the serum of flystruck sheep. It is suggested that, under certain circumstances, these inhibitors may be involved in influencing flystrike through reducing the activity of larval proteases necessary for wound formation and larval nutrition.