Increased vascular endothelial cell markers in patients with disseminated intravascular coagulation

A single-center study of reference intervals for TAT, PIC, TM and t-PAIC in healthy older Chinese adults

OBJECTIVE

To explore the distribution of thrombin-antithrombin complex (TAT), plasmin-α2-antiplasmin inhibitor complex (PIC), thrombomodulin (TM), and tissue plasminogen activator-inhibitor complex (t-PAIC) in healthy older Chinese adults, and establish the reference intervals (RIs).

METHODS

The Biotech Shine i2900 chemiluminescence immune assay was used to measure the plasma concentrations of TAT, PIC, TM, and t-PAIC in 1628 adults ≥ 60 years. The RIs were established using the 2.5th and 97.5th percentiles of the distribution.

RESULTS

TAT levels were lower in males than females across all ages. Differences between the ages of 60-79 and ≥ 80 in both sex groups were statistically significant, with an upward trend with age. PIC levels showed no difference between the sexes but increased with age in both groups. TM levels did not differ between the sex groups, with slight fluctuation with age. The level in females aged 60-69 was slightly higher than that in the other groups; the difference was statistically significant. T-PAIC levels were not significantly different between the sex groups, with less fluctuation with sex and age. The level in males ≥ 80 years old was slightly lower than that in the other groups; the difference was statistically significant. The RIs for all markers in healthy older Chinese adults were determined and statistically reported by age and sex. For TAT, the RIs for males aged 60-79 and ≥ 80 are 0.51-2.30 ng/mL and 0.88-3.72 ng/mL, respectively, whereas for females aged 60-79 and ≥ 80, the RIs are 0.68-2.82 ng/mL and 1.02-3.67 ng/mL, respectively. For PIC, the RIs for the age groups 60-69, 70-79, and ≥ 80 are 0.10-0.89 µg/mL, 0.12-1.00 µg/mL, and 0.21-1.04 µg/mL, respectively. The RI of TM for females aged 60-69 is 3.32-13.22 TU/mL, whereas it is 2.96-13.26 TU/mL for the other groups. The RI of t-PAIC for males aged ≥ 80 is 1.63-10.68 ng/mL, whereas it is 2.33-11.34 ng/mL for the other groups.

CONCLUSIONS

Discrepancies exist in thrombus markers among different sex and age groups. The RIs of TAT, PIC, TM and t-PAIC for healthy older Chinese adults were successfully established.

Thrombotic Mechanism Involving Platelet Activation, Hypercoagulability and Hypofibrinolysis in Coronavirus Disease 2019

Coronavirus disease 2019 (COVID-19) has spread, with thrombotic complications being increasingly frequently reported. Although thrombosis is frequently complicated in septic patients, there are some differences in the thrombosis noted with COVID-19 and that noted with bacterial infections. The incidence (6-26%) of thrombosis varied among reports in patients with COVID-19; the incidences of venous thromboembolism and acute arterial thrombosis were 4.8-21.0% and 0.7-3.7%, respectively. Although disseminated intravascular coagulation (DIC) is frequently associated with bacterial infections, a few cases of DIC have been reported in association with COVID-19. Fibrin-related markers, such as D-dimer levels, are extremely high in bacterial infections, whereas soluble C-type lectin-like receptor 2 (sCLEC-2) levels are high in COVID-19, suggesting that hypercoagulable and hyperfibrinolytic states are predominant in bacterial infections, whereas hypercoagulable and hypofibrinolytic states with platelet activation are predominant in COVID-19. Marked platelet activation, hypercoagulability and hypofibrinolytic states may cause thrombosis in patients with COVID-19.

Circulating Thrombomodulin: Release Mechanisms, Measurements, and Levels in Diseases and Medical Procedures

Thrombomodulin (TM) is a type-I transmembrane protein that is mainly expressed on endothelial cells and plays important roles in many biological processes. Circulating TM of different forms are also present in biofluids, such as blood and urine. Soluble TM (sTM), comprised of several domains of TM, is the major circulating TM which is generated by either enzymatic or chemical cleavage of the intact protein under different conditions. Under normal conditions, sTM is present in low concentrations (<10 ng/mL) in the blood but is elevated in several pathological conditions associated with endothelial dysfunction such as cardiovascular, inflammatory, infection, and metabolic diseases. Therefore, sTM level has been examined for monitoring disease development, such as disseminated intravascular coagulation (DIC), sepsis and multiple organ dysfunction syndrome in patients with novel coronavirus disease 2019 (COVID-19) recently. In addition, microvesicles (MVs) that contain membrane TM (MV-TM) have been found to be released from activated cells which also contribute to levels of circulating TM in certain diseases. Several release mechanisms of sTM and MV-TM have been reported, including enzymatic, chemical, and TM mutation mechanisms. Measurements of sTM and MV-TM have been developed and explored as biomarkers in many diseases. In this review, we summarize all these advances in three categories as follows: (1) release mechanisms of circulating TM, (2) methods for measuring circulating TM in biological samples, and (3) correlation of circulating TM with diseases. Altogether, it provides a whole picture of recent advances on circulating TM in health and disease.

Thrombocytopenia and increased risk of adverse outcome in COVID-19 patients

Background

Thrombocytopenia was common in the coronavirus disease 2019 (COVID-19) patients during the infection, while the role of thrombocytopenia in COVID-19 pathogenesis and its relationship with systemic host response remained obscure. The study aimed to systematically evaluate the relationship between thrombocytopenia in COVID-19 patients and clinical, haematological and biochemical markers of the disease as well as adverse outcomes.

Methods

To assess the relationship between abnormal platelet levels and disease progression, a multi-center retrospective cohort study was conducted. COVID-19 patients with thrombocytopenia and a sub-cohort of matched patients without thrombocytopenia were compared for their clinical manifestations, haematological disorders, biochemical parameters, inflammatory markers and clinical outcome.

Results

Thrombocytopenia was present in 127 of 2,209 analyzed patients on admission. Compared with the control group, thrombocytopenia patients developed significantly higher frequency of respiratory failure (41.9% vs. 22.6%, P = 0.020), intensive care unit entrance (25.6% vs. 11.5%, P = 0.012), disseminated intravascular coagulation (45.2% vs. 10.6%, P < 0.001), more altered platelet morphology indexes and coagulation perturbation, higher levels of inflammatory markers. In addition, a significantly increased all-cause mortality (hazard ratio 3.08, 95% confidence interval 2.26-4.18, P < 0.001) was also observed in the patients with thrombocytopenia. Late development of thrombocytopenia beyond 14 days post-symptom was observed in 61 patients, from whom a comparable mortality rate yet longer duration to death was observed compared to those with early thrombocytopenia.

Conclusions

Our finding from this study adds to previous evidence that thrombocytopenia is associated with adverse outcome of the disease and recommend that platelet count and indices be included alongside other haematological, biochemical and inflammatory markers in COVID-19 patients' assessment during the hospital stay.

C-type lectin family XIV members and angiogenesis

The growth and metastasis of tumors is dependent on angiogenesis. C-type lectins are carbohydrate-binding proteins with a diverse range of functions. The C-type lectin family XIV members are transmembrane glycoproteins, and all four members of this family have been reported to regulate angiogenesis, although the detailed mechanism of action has yet to be completely elucidated. They interact with extracellular matrix proteins and mediate cell-cell adhesion by their lectin-like domain. The aim of the present study was to summarize the available information on the function and mechanism of C-type lectin family XIV in angiogenesis and discuss their potential as targets for cancer therapy.

Serum thrombomodulin as a newly identified biomarker for postoperative lung injury: a prospective observational study

Postoperative lung injury after lung cancer resection is still a difficult problem to be solved. Thrombomodulin (TM) is a membrane-bound glycoprotein of endothelial cells, and its serum level is elevated in patients with acute lung injury or acute respiratory distress syndrome. In fact, TM is abundant in the pulmonary capillary vessels. Lung resection reduces the volume of pulmonary capillary vessels; however, the change in the serum levels of TM after lung resection remains to be investigated. We therefore analyzed the postoperative changes in the serum TM levels in 60 patients who underwent thoracotomy without lung resection (n = 3), partial resection of the lung (n = 15), or lobectomy (n = 42). Preoperative and postoperative day-1 laboratory data including the serum levels of TM and KL-6, a sialylated carbohydrate antigen (a biomarker for pulmonary fibrosis), and oxygenation index were collected. Unexpectedly, the postoperative serum levels of TM were lower than preoperative values in lobectomy group, whereas they remained unchanged after thoracotomy without lung resection and after partial resection of the lung. In addition, the serum TM level decreased proportional to the resected lung volume. Eight out of 42 patients with lobectomy presented high postoperative serum levels of TM, and 3 out of these 8 patients presented postoperative impaired oxygenation. Postoperative impaired oxygenation occurred only in patients with elevated TM levels; namely, an increase of serum TM is associated with impaired oxygenation after lung resection. In conclusion, serum TM is a possible biomarker for predicting the occurrence of postoperative lung injury.

The role of FB21 as a marker of glomerular endothelial cell injury

FB21 was reactive with the glomerular endothelial cells and distal tubules of the human kidney and was bound to a sialic-acid-dependent cell surface antigen. We evaluated the FB21 staining in fetal kidneys, and the kidneys of children and adults with normal kidneys and glomerulonephritis and investigated whether FB21 can be used as a marker for endothelial cell injury. FB21 was reactive with the endothelial cells of normal kidneys and was detected on the surface of endothelial cells by immunoelectron microscopy. FB21 was reactive with endothelial cells in the kidneys of over 32-week fetuses. The endothelial cell FB21 staining scores in the first renal biopsy specimens of patients with hemolytic uremic syndrome (HUS) were lower than in the kidneys of children with normal kidneys and was negatively correlated with their serum E-selectin concentrations. The FB21 staining of glomerular endothelial cells was similar to the staining for the other endothelial markers, CD34 and von Willebrand factor (vWF). However, FB21 staining of interstitial blood vessels was very weak and was distinct from that of other endothelial markers. These results suggest that FB21 can be used as a specific marker for glomerular endothelial cell injury in various types of glomerulonephritis.

Cold Injury Syndrome and Neurodevelopmental Changes in Survivors

BACKGROUND

The aim of this study was to extend and develop knowledge of the clinical parameters of cold injury syndrome (CIS) in hypothermic infants and newborns, so that morbidity, mortality, and neurodevelopmental disturbances associated with the condition can be reduced.

METHODS

This retrospective, 10-year cohort study investigated 103 hypothermic infant and newborn patients (aged 0-60 days) admitted to the Pediatric Department between January 1, 1976 and December 31, 1985. Medical records of 67 survivors and 36 children who died were analyzed. Of the survivors, 24 consented to undergo assessment of neuropsychological and neurodevelopmental outcomes.

RESULTS

At presentation, all patients manifested cold skin and limbs, while 96 (93.2%) were sleepy, hypotonic and inactive. Cyanosis with bradycardia, bradypnea, and apneic crisis (AC) was observed in 80 (77.7%) patients, and 65 (63.1%) demonstrated diffuse intravascular coagulation (DIC). Pulmonary hemorrhage, AC, respiratory distress syndrome, and DIC represented the primary causes of death. Higher body temperatures on admission reduced the risk of death. Of the 24 patients assessed for neuropsychological and neurodevelopmental outcomes, all but one had normal intellectual capabilities, whereas 16 (66.7%) showed signs of neurodevelopmental disturbances.

CONCLUSIONS

The severity of hypothermia, leukopenia, and thrombocytopenia with DIC correlates with prognosis and death rate. Hypothermia in infants and newborns can cause psychological and neurodevelopmental disturbances in survivors.

FB21, a monoclonal antibody that reacts with a sialic-acid-dependent carbohydrate epitope, is a marker for glomerular endothelial cell injury

BACKGROUND

FB21 is reactive with glomerular endothelial cells and distal tubules of the human kidney and is bound to a sialic-acid-dependent cell-surface antigen. We evaluated FB21 staining in fetal kidneys and kidneys of children and adults with normal kidneys and glomerulonephritis and investigated whether FB21 can be used as a marker for endothelial cell injury.

METHODS

This study was performed on 6 children, 10 adults, and 12 fetuses with normal kidneys and 113 patients diagnosed with primary and secondary glomerulonephritis. We evaluated renal staining for FB21 in children with normal kidneys and glomerulonephritis and measured serum E-selectin concentrations in patients with hemolytic uremic syndrome (HUS) and Henoch-Schönlein purpura nephritis (HSPN).

RESULTS

(1) FB21 was reactive with endothelial cells of normal kidneys and detected on the surface of endothelial cells by immunoelectron microscopy. (2) FB21 was reactive with endothelial cells in kidneys of fetuses older than 32 weeks. (3) Endothelial cell FB21 staining scores in the first renal biopsy specimens of patients with HUS and HSPN were lower than those in normal kidneys of children and correlated negatively with serum E-selectin concentrations. (4) Endothelial cell FB21 staining of crescentic and sclerotic glomerular lesions in patients with immunoglobulin A nephropathy, membranoproliferative glomerulonephritis, and focal glomerulosclerosis was weaker than that in normal kidneys.

CONCLUSION

These results suggest that FB21 can be used as a marker for glomerular endothelial cell injury in various types of glomerulonephritis.

Plasma levels of heparin cofactor II (HCII) and thrombin-HCII complex in patients with disseminated intravascular coagulation

Plasma levels of heparin cofactor II (HCII), thrombin-HCII complex (THC), antithrombin (AT), and thrombin-AT complex (TAT) were evaluated in patients with disseminated intravascular coagulation (DIC) associated with several underlying diseases. Plasma levels of AT were significantly reduced in almost all underlying diseases associated with DIC, but the plasma levels of HCII and HCII/AT ratio were significantly reduced only in patients with infections. While the plasma level of TAT was significantly increased in patients with all underlying diseases associated with DIC, the increase of THC was not significant. Plasma levels of AT were significantly reduced in DIC and pre-DIC associated with almost all underlying diseases, but those of HCII were significantly reduced only in DIC and pre-DIC patients with inflammatory diseases. The plasma levels of TAT were significantly increased in DIC, pre-DIC, and non-DIC patients with all underlying diseases, and those of THC were significantly increased in DIC and pre-DIC patients with inflammatory diseases. The plasma levels of THC were not significantly increased in non-DIC patients of any disease group. The decrease of AT may be caused by thrombin generation or inflammatory reaction that occurs in DIC associated with underlying diseases, while the decrease of HCII might be caused by both thrombin generation and inflammatory reaction. Finally, AT inhibits thrombin more strongly than HCII in several underlying diseases associated with DIC except for inflammatory diseases. In inflammatory diseases, HCII might play an important role in preventing the onset of DIC.

Hemostatic abnormalities following bone marrow transplantation

Hemostatic abnormalities in 26 patients following bone marrow transplantation (BMT) were examined. In the event-free survival group, the plasma levels of antithrombin (AT) and protein C (PC) were significantly decreased 1 and 2 weeks after BMT, and the plasma levels of thrombomodulin (TM) and tissue plasminogen activator-plasminogen activator inhibitor-1 complex (tPA-PAI-I complex) were significantly increased from 4 weeks to 13 weeks after BMT. Excepting AT, there was no significant difference in hemostatic parameters before BMT among the event-free survival, 6-month survival, and death within 6 months groups. On day 0 following BMT, only plasma AT levels were significantly lower in the 6-month survival group than in the death within 6 months group. From 1 to 3 weeks after BMT, plasma levels of AT or PC were significantly lower in the death within 6 months group than in the 6-month survival group. From 1 to 5 weeks after BMT, the plasma levels of TM and tissue type plasminogen activator-plasminogen activator inhibitor-I complex (tPA-PAI-I complex) were significantly higher in the 6-month survival group than in the death within 6 months group. From 1 to 13 weeks after BMT, the plasma levels of D-dimer or soluble fibrin monomer (SFM) were significantly higher in the death within 6 months group than in the 6-month survival group. There was no remarkable difference in plasma levels of thrombin-antithrombin comlex or plasmin-plasmin inhibitor complex following BMT between these groups of patients. These findings suggest that the decrease in the plasma AT or PC level reflects early occurrence of complications of prognostic significance and that the increase in vascular endothelial cell markers such as plasma levels of TM or tPA-PAI-I complex reflects occurrence of complications during the middle course of BMT. Plasma levels of D-dimer and SFM may be useful markers for predicting complications associated with poor prognosis after BMT.

Plasma levels of total plasminogen activator inhibitor-I (PAI-I) and tPA/PAI-1 complex in patients with disseminated intravascular coagulation and thrombotic thrombocytopenic purpura

In this study, we examined changes in the plasma levels of total plasminogen activator inhibitor-I (PAI-I) and tissue-type plasminogen activator (tPA)/PAI-I complex in patients with disseminated intravascular coagulation (DIC) and in those with thrombotic thrombocytopenic purpura (TTP) to investigate the fibrinolytic function and its relation to organ failure. The plasma levels of total PAI-1 and tPA/PAI-I complex were significantly higher in patients with DIC, pre-DIC, and TTP than in those with non-DIC. The plasma levels of thrombin-antithrombin complex (TAT), plasmin-plasmin inhibitor complex (PPIC), D-dimer, thrombomodulin (TM), total PAI-I, and tPA/PAI-I complex were significantly higher in patients with organ failure than in those without organ failure. The plasma levels of total PAI-I and tPA/PAI-I complex were markedly increased in patients with acute leukemia. The plasma levels of total PAI-I, but not those of tPA/PAI-I complex, were significantly increased in patients with sepsis or with solid cancer. In all cases, total PAI-I or tPA/PAI-I complex was not significantly correlated with any hemostatic marker. Measurement of total PAI-I and tPA/PAI-I complex may be useful in the diagnosis of DIC.

Increased plasma levels of tissue factor pathway inhibitor-activated factor X complex in patients with disseminated intravascular coagulation

Plasma levels of tissue factor pathway inhibitor (TFPI)-activated factor Xa (FXa) complex were measured in patients with disseminated intravascular coagulation (DIC), pre-DIC, and DIC. Plasma levels of plasmin-plasmin inhibitor complex (PPIC), D-dimer, and soluble fibrin monomer (SFM) were significantly higher in patients with DIC than in those with pre-DIC or non-DIC; the levels of these hemostatic markers were significantly higher in patients with pre-DIC than in those with non-DIC. Plasma levels of thrombin-antithrombin complex (TAT) were significantly higher in patients with DIC or pre-DIC than in those with non-DIC. Plasma levels of tissue factor (TF), total TFPI, free TFPI, and TFPI-Xa complex were significantly higher in patients with DIC than in those with non-DIC. Plasma levels of TFPI-Xa complex were significantly increased in patients with pre-DIC as compared to those with non-DIC; however, plasma free TFPI levels were significantly decreased in patients with pre-DIC as compared to those with non-DIC. These findings suggest that free TFPI might be consumed in the pre-DIC state, thereby confirming the activation of the extrinsic pathway. Plasma levels of TFPI-Xa complex were significantly correlated with TF, free TFPI, and total TFPI. Increased plasma TFPI-Xa complex levels might be useful for the diagnosis of DIC or pre-DIC, particularly that occurring by activation of the extrinsic pathway of blood coagulation.

Coagulation tests and anti-phospholipid antibodies in patients positive for lupus anticoagulant

We examined activated partial thromboplastin time, kaolin clotting time, mixing with normal plasma in kaolin clotting time, dilute Russell's viper venom time, dilute Russell's viper venom time at high lipid concentrations, anti-phospholipid antibodies, and anti-cardiolipin-beta2-glycoprotein I complex antibody in 135 patients with prolongation of activated partial thromboplastin time and diagnosed 86 patients positive for lupus anticoagulant. The sensitivity of activated partial thromboplastin time and dilute Russell's viper venom time/dilute Russell's viper venom time-high lipid concentrations ratio for lupus anticoagulant were markedly high, but the specificity of activated partial thromboplastin time for lupus anticoagulant was not markedly high. The specificity, but not the sensitivity, of kaolin clotting time-mixing with normal plasma in kaolin clotting time was markedly high. In summary, dilute Russell's viper venom time to dilute Russell's viper venom time-high lipid concentrations ratio gave high sensitivity as well as specificity, being the only assay to confirm this. Of the patients positive for lupus anticoagulant, 25% were positive for anti-phospholipid antibodies and 17% were positive for anti-cardiolipin-beta2-glycoprotein I complex antibody. Of the lupus anticoagulant-positive patients with thrombosis, 45% were positive for anti-phospholipid antibodies, 35% were positive for anti-cardiolipin-beta2-glycoprotein I complex antibody, 60% were positive for both anti-phospholipid antibodies and anti-cardiolipin-beta2-glycoprotein I complex antibody, and only 17% were negative for anti-phospholipid antibodies and anti-cardiolipin-beta2-glycoprotein I complex antibody. These findings suggest that lupus anticoagulant can be diagnosed by dilute Russell's viper venom time/dilute Russell's viper venom time-high lipid concentrations ratio, and that thrombosis in lupus anticoagulant-positive may be predictable from both anti-phospholipid antibodies and anti-cardiolipin-beta2-glycoprotein I complex antibody. Plasma tissue type plasminogen activator level in lupus anticoagulant patients was significantly increased, and plasma tissue type plasminogen activator and fibrin-D-dimer levels in lupus anticoagulant-positive patients with thrombosis were significantly higher than in those without thrombosis, suggesting that the diagnosis of thrombosis by hemostatic markers might be important in lupus anticoagulant.

Endothelial cell and hemostatic activation in relation to cytokines in patients with sepsis

Sepsis is commonly associated with disturbances of the hemostatic balance. Most of the pathophysiological changes in sepsis are caused by endotoxin acting directly through endothelial injury or indirectly through release of cytokines with procoagulant effects. The relation between cytokines and hemostatic parameters was assessed in 32 patients with sepsis. Prothrombin fragment 1+2 (F1+2), thrombin-antithrombin III complexes (TAT), tissue type plasminogen activator (t-PA) functional and antigen, plasminogen activator inhibitor-1 (PAI-1), plasminalpha2-antiplasmin complexes (PAP), D-Dimer, thrombomodulin (TM) and von Willebrand factor (vWF) were measured in patients and in 30 healthy subjects. The levels of cytokines TNF-alpha and interleukin-6 (IL-6) also were determined. A significant increase of F1+2, TAT, PAI-1, PAP, and D-Dimer was observed in septic patients as compared with controls (p<0.0001), whereas t-PA activity was significantly reduced (p<0.01). The markers of endothelial cell activation TM, vWF, and t-PA antigen also were elevated significantly as compared with the control group (p<0.01). Finally, we found a marked increase of TNF-alpha and IL-6 (p<0.0001). Whereas the increase of cytokine levels could be partially responsible for the hemostatic activation, it did not correlate with markers of endothelial activation in patients with sepsis.

Hemostatic molecular markers before the onset of disseminated intravascular coagulation

We retrospectively measured various hemostatic markers in 240 patients with disseminated intravascular coagulation (DIC) before the onset of DIC and in 110 non-DIC patients, and examined their usefulness for the diagnosis of pre-DIC. Changes in prothrombin time ratio and fibrinogen levels were not significant before the onset of DIC. The plasma levels of fibrinogen and fibrin degradation products before the onset of DIC were increased and the platelet count was gradually reduced in nonleukemic patients; these changes were already significant in the non-DIC state. The plasma levels of thrombin-antithrombin complex (TAT), plasmin-plasmin inhibitor complex (PPIC), D-dimer, and soluble fibrin monomer (sFM) were increased before the onset of DIC. In leukemic patients, the plasma levels of sFM on day 5, those of TAT on day 3, and D-dimer on day 1, were significantly increased before the onset of DIC. The levels of most hemostatic markers 7 days before the onset of DIC were not different from those observed in the non-DIC state. In nonleukemic patients, only D-dimer, sFM, and TAT levels were significantly increased 7 days before the onset of DIC compared with values in the non-DIC state. The positive rate of hemostatic markers for the diagnosis of DIC, TAT, and PPIC were high during the pre-DIC and non-DIC groups. The plasma levels of sFM and D-dimer were low in non-DIC and increased gradually during the pre-DIC state. These findings suggest that hemostatic molecular markers such as sFM, D-dimer, and TAT are useful for the diagnosis of pre-DIC, although their cutoff values were different among various diseases.

Increased truncated form of plasma tissue factor pathway inhibitor levels in patients with disseminated intravascular coagulation

To evaluate that the relationship between the truncated form of tissue factor pathway inhibitor (TFPI) and the stage of disseminated intravascular coagulation (DIC), we measured the plasma levels of tissue factor (TF) antigen and the intact and truncated forms of TFPI antigens in 41 patients with DIC, 12 with pre-DIC, and 20 with non-DIC. The plasma TF and total TFPI antigen levels were significantly higher in patients with DIC than in non-DIC patients. Plasma levels of intact TFPI antigen in the pre-DIC groups were significantly lower than in the non-DIC and DIC groups. The truncated form of TFPI antigen levels in DIC patients were significantly increased compared with those in non-DIC and pre-DIC patients. The fact that the intact form of TFPI was decreased in pre-DIC patients compared with that in non-DIC patients, suggests that it is consumed in the pre-DIC state and that hypercoagulability occurs in pre-DIC patients. The increased level of the truncated form of TFPI in DIC patients may be attributed to proteolysis of the intact form of TFPI in these patients. The increased level of the truncated form of TFPI may be a useful index for the diagnosis of DIC.

Poor outcome in disseminated intravascular coagulation or thrombotic thrombocytopenic purpura patients with severe vascular endothelial cell injuries

Various hemostatic and vascular endothelial cell markers were measured in patients with disseminated intravascular coagulation (DIC), non-DIC, or thrombotic thrombocytopenic purpura (TTP) and in healthy volunteers to examine the relationships between the hemostatic abnormalities or vascular endothelial cell injuries and the patients' outcomes. Although the plasma levels of soluble fibrin monomer, thrombin-antithrombin complex, plasmin-plasmin inhibitor complex, and D-dimer were significantly increased in the DIC patients, there were no significant differences in these markers between the DIC patients who survived and those who died, suggesting that these markers might not be directly related to the patient outcome. The plasma thrombomodulin (TM) levels in the DIC and TTP patients were significantly higher than those in the healthy volunteers, and the plasma TM levels in the patients who died were significantly higher than those in the patients who survived. These findings showed that the TM level reflected the outcome, and that the outcome of the diseases underlying DIC and TTP might depend on vascular endothelial cell injuries. The plasma protein C and antithrombin activities were markedly reduced in the DIC, non-DIC, and TTP patients who died compared to those who survived. These findings suggest that reduced plasma antithrombin and protein C activities are useful markers of systemic vascular endothelial injuries. Although the plasma tissue factor (TF) levels were significantly increased in the DIC patients, there was no significant difference in the plasma TF levels between the DIC patients who died and those who survived. In conclusion, we found that the outcome of the diseases underlying DIC and TTP is related to vascular endothelial cells, and that plasma TM, antithrombin, and protein C are useful markers for systemic vascular endothelial cell injury.

Increased levels of the soluble adhesion molecule E-selectin in patients with chronic myeloproliferative disorders and thromboembolic complications

Patients with chronic myeloproliferative disorders (CMD) show a high frequency of thrombosis. For this reason we evaluated endothelial cell markers, soluble adhesion molecule E-selectin (sELAM), and thrombomodulin (TM) in 25 patients with CMD. Among them nine presented thromboses in their past history. Data were compared with those obtained in a group of healthy subjects and a group of patients with secondary thrombocytosis. The mean plasma concentrations of sELAM were elevated in patients with CMD, as compared with healthy subjects (81.27 +/- 42.8 ng/ml vs. 41.75 +/- 13; P < 0.02). Similarly, the mean plasma concentrations of sTM were increased in CMD patients in comparison with the control group (102.0 +/- 73 ng/ml vs. 16.7 +/- 9.6; P < 0.01). More markedly elevated sELAM levels were observed in CMD patients with thrombosis than in patients without thrombosis (113.16 +/- 29.5 ng/ml vs. 55.11 +/- 19.1 ng/ml; P < 0.001), while no significant difference was found between CMD patients without thrombosis and secondary thrombocytosis (50.72 +/- 10.8 ng/ml). Plasma thrombomodulin values in CMD patients with thrombosis (131 +/- 93.8 ng/ml) were higher than those without thrombosis (65.77 +/- 43.9 ng/ml; P < 0.02). sTM values were also significantly increased in patients with secondary thrombocytosis (P < 0.01). It is speculated that the plasma, sELAM levels may reflect endothelium activation and that it is possibly useful in predicting the thrombotic risk in myeloproliferative disorders.

Increased levels of the soluble adhesion molecule E-selectin in patients with chronic myeloproliferative disorders and thromboembolic complications

Patients with chronic myeloproliferative disorders (CMD) show a high frequency of thrombosis. For this reason we evaluated endothelial cell markers, soluble adhesion molecule E-selectin (sELAM), and thrombomodulin (TM) in 25 patients with CMD. Among them nine presented thromboses in their past history. Data were compared with those obtained in a group of healthy subjects and a group of patients with secondary thrombocytosis. The mean plasma concentrations of sELAM were elevated in patients with CMD, as compared with healthy subjects (81.27 +/- 42.8 ng/ml vs. 41.75 +/- 13; P < 0.02). Similarly, the mean plasma concentrations of sTM were increased in CMD patients in comparison with the control group (102.0 +/- 73 ng/ml vs. 16.7 +/- 9.6; P < 0.01). More markedly elevated sELAM levels were observed in CMD patients with thrombosis than in patients without thrombosis (113.16 +/- 29.5 ng/ml vs. 55.11 +/- 19.1 ng/ml; P < 0.001), while no significant difference was found between CMD patients without thrombosis and secondary thrombocytosis (50.72 +/- 10.8 ng/ml). Plasma thrombomodulin values in CMD patients with thrombosis (131 +/- 93.8 ng/ml) were higher than those without thrombosis (65.77 +/- 43.9 ng/ml; P < 0.02). sTM values were also significantly increased in patients with secondary thrombocytosis (P < 0.01). It is speculated that the plasma, sELAM levels may reflect endothelium activation and that it is possibly useful in predicting the thrombotic risk in myeloproliferative disorders.

Haemostasis balance disorders in patients with essential hypertension

This study was aimed at investigating haemostasis parameters in patients (pts) with arterial hypertension (AH) before any medical treatment and to correlate these findings with those in healthy normal Greek population 83 pts (48 m, 35 w) mean age 49.8 +/- 10.1 yrs, body mass index 23.4 +/- 1.5 with mild to moderate AH and 42 healthy volunteers matched for sex (24 m, 18 w), age 51.2 +/- 10.5 yrs and body mass index 22.8 +/- 1.46 were studied. Fibrinogen, vWF, plasminogen, ECLT, a2 antiplasmin, tPA-Ag, PAI-1 in all pts and in the control group were measured. Mean age and BMI did not significantly differ between the two groups. The hypertensive patients had significantly higher levels of fibrinogen (327.75 +/- 51.36 vs. 272.84 +/- 46.8 mg/dl), tPA-Ag (8.81 +/- 3.32 vs. 5.76 +/- 2.54 ng/ml) and PAI-1 (11.8 +/- 10.9 vs. 7.91 +/- 5.5 IU/ml), whereas a2 antiplasmin level was significantly lower (98.71 +/- 15.40 vs. 107.84 +/- 17.52%). No differences were found between hypertensives and normal subjects in vWF, plasminogen and ECLT. These preliminary data suggest that in pts with mild to moderate AH, before any medical treatment, there are significantly higher levels of fibrinogen, tPA-Ag and PAI-1 compared with normal volunteers, whereas there are significantly lower a antiplasmin levels. These findings indicate a disturbance in the haemostasis balance with hypercoagulability and fibrinolytic deficiency.

Plasma thrombomodulin level in very low birthweight infants at birth

OBJECTIVE

Plasma soluble thrombomodulin level reflects endothelial damage. The plasma thrombomodulin level at birth is increased in asphyxiated full-term infants. There is no report of plasma thrombomodulin level in premature infants. To determine the thrombomodulin level in premature infants and whether it might reflect endothelial damage, we examined the plasma thrombomodulin level in very low birthweight (VLBW) infants at birth.

METHODS

Forty-five VLBW infants, of whom 14 had perinatal asphyxia complications, were recruited. As a control, 50 full-term infants without complications were also studied. Plasma thrombomodulin concentration, pH, base deficit, serum creatinine and D-dimer concentration, platelet count and fibrinogen concentration were measured within 1 hour after birth.

RESULTS

There were significant differences in plasma pH, creatinine concentration, platelet count, antithrombin III activity and D-dimer concentration between VLBW infants and full-term infants. Plasma thrombomodulin concentration (39.0 (16.6-93.7) vs 27.0 (16.6-39.1) microg/L, p < 0.0001) and plasma thrombomodulin-to-serum creatinine ratio (0.82 (0.19-2.65) vs 0.47 (0.24-0.70) microg/micromol, p < 0.0001) were significantly higher in VLBW infants than those in full-term infants. By univariate analyses for all neonates, there were significant relations between plasma thrombomodulin concentration and gestational age, birthweight, plasma pH, creatinine concentration, platelet count and antithrombin III activity. A stepwise multiple linear regression model using the above variables as dependent factors showed only birthweight contributed significantly to plasma thrombomodulin concentration (plasma thrombomodulin concentration (microg/l) = 45.677-0.006 (birthweight; g), r2 = 0.323, p < 0.0001, n = 94). Plasma thrombomodulin concentration and plasma thrombomodulin-to -serum creatinine ratio in VLBW infants with asphyxia were higher than in those without asphyxia, but not significantly different (43.2 +/- 17.7 vs 38.3 +/- 8.5 microg/l and 0.92 +/- 0.60 vs 0.83 +/- 0.37 microg/micromol).

CONCLUSION

Plasma thrombomodulin level in VLBW infants shows a high value at birth, and we consider the main factor responsible for this elevation may be endothelial damage or low clearance rate of thrombomodulin, which may be related to early gestational age.

Plasma-activated factor VII level in patients positive for lupus anticoagulant

We examined plasma levels of activated factor VII (F VIla) in 50 patients positive for lupus anticoagulant (LA), in 83 patients negative for LA, and in 10 healthy volunteers as controls. Plasma F VIIa was present in healthy volunteers; its level was significantly increased, compared to the level in the controls, in patients with thrombosis, collagen diseases, and disseminated intravascular coagulation (DIC), suggesting that it reflected a thrombotic state. Plasma F VIIa was correlated with thrombin-antithrombin complex (TAT) in patients negative for LA but showed no such correlation in those positive for LA. Plasma F VIIa was negatively correlated with activated partial thromboplastin time (APTT) in patients positive for LA, but not in those negative for LA, suggesting that LA could inhibit the F VIIa assay system. Plasma F VIIa level was significantly increased in patients with thrombotic diseases; however, in patients positive for LA, it is possible that increased plasma F VIIa level may not be correlated with thrombogenicity.

Plasma thrombomodulin level in newborn infants with and without perinatal asphyxia

To determine whether vascular endothelial damage occurs in neonates with asphyxia, we examined the plasma thrombomodulin level at birth in infants with and without asphyxia. The plasma thrombomodulin concentration in 11 asphyxiated infants was significantly elevated compared with that in 48 infants without asphyxia (38.1 vs 27.0 micrograms/l, p < 0.0001). The plasma thrombomodulin-to-serum creatinine ratio was also significantly elevated (0.62 vs 0.48 microgram/mumol, p = 0.0005). The plasma thrombomodulin concentration and the plasma thrombomodulin-to-serum creatinine ratio in infants without asphyxia did not differ between the two types of delivery: normal vaginal delivery and elective caesarean section. Stepwise regression analysis showed the serum D-dimer concentration, plasma pH and serum creatinine concentration were significant independent variables for plasma thrombomodulin concentration, whereas base deficit, platelet count, fibrinogen concentrations and antithrombin III activity were not. Our data suggest that vascular endothelial damage might occur in asphyxiated infants.

Plasma tissue factor and tissue factor pathway inhibitor levels in patients with disseminated intravascular coagulation

We measured the plasma levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in patients with disseminated intravascular coagulation (DIC) to examine the relationship between TFPI and vascular endothelial cell injury. Plasma TF (273 +/- 90 pg/ml) and TFPI (252 +/- 125 ng/ml) levels were significantly increased in patients with DIC compared with non-DIC patients. Plasma TF antigen level was significantly increased in pre-DIC patients (285 +/- 85 pg/ml), while the plasma TFPI level (152 +/- 54 ng/ml) was not markedly increased in such a state. The plasma TF/TFPI ratio was high in the pre-DIC patients (2.10 +/- 0.90), and low in the DIC patients (1.40 +/- 0.87) and healthy volunteers (0.84 +/- 0.26). There was no significant difference between the DIC patients with a good outcome and those with a poor outcome in terms of plasma TF levels, although the plasma TFPI level in the DIC patients with a good outcome (289 +/- 133 ng/ml) was significantly higher than that in those with a poor outcome (187 +/- 75 ng/ml). During the clinical course of DIC, plasma TF antigen was increased first, and an increase of the plasma TFPI level followed the increase in plasma TF level. These findings suggest that plasma TFPI is released from vascular endothelial cells and it may reflect vascular endothelial cell injury. It is conceivable that TF and TFPI may play an important role in the onset of DIC.