Improvement of appropriate pharmacological prophylaxis in hospitalised cancer patients with a multiscreen e-alert system: a single-centre experience

PURPOSE

Thromboprophylaxis use among medical inpatients, including cancer patients, is suboptimal. We aimed to evaluate the impact of a novel multiscreen version (v2.0) of an e-alert system for VTE prevention in hospitalised cancer medical patients compared to the original software.

METHODS

Prospective study including 989 consecutive adult cancer patients with high-risk of VTE. Patients were followed-up 30 days post-discharge. Two periods were defined, according to the operative software.

RESULTS

E-alert v2.0 was associated with an increase in the use of LMWH prophylaxis (65.5% vs. 72.0%); risk difference (95% CI) 0.064 (0.0043-0.12). Only 16% of patients in whom LMWH prophylaxis was not prescribed lacked a contraindication. No significant differences in the rates of VTE (2.9% vs. 3.2%) and major bleeding (2.7% vs. 4.0%) were observed.

CONCLUSIONS

E-alert v2.0 further increased the use of appropriate thromboprophylaxis in hospitalised cancer patients, although was not associated with a reduction in VTE incidence.

Group V secretory phospholipase A2 impairs endothelial protein C receptor-dependent protein C activation and accelerates thrombosis in vivo

BACKGROUND

Endothelial protein C receptor (EPCR) must be bound to a molecule of phosphatidylcholine (PC) to be fully functional, i.e. to interact with protein C/activated protein C (APC) properly. PC can be replaced with other lipids, such as lysophosphatidylcholine or platelet-activating factor, by the action of group V secretory phospholipase A2 (sPLA2-V), an enzyme that is upregulated in a variety of inflammatory conditions. Studies in purified systems have demonstrated that the substitution of PC notably impairs EPCR function in a process called EPCR encryption.

OBJECTIVES

To analyze whether sPLA2-V was able to regulate EPCR-dependent protein C activation in vivo, and its impact on thrombosis and the hemostatic system.

METHODS

Mice were transfected with sPLA2-V by hydrodynamic gene delivery. The effects on thrombosis were studied with the laser carotid artery occlusion model, and APC generation capacity was measured with ELISA. Global hemostasis was analyzed with thromboelastometry.

RESULTS

We found that sPLA2-V overexpression in mice significantly decreased their ability to generate APC. Furthermore, a murine carotid artery laser thrombosis model revealed that higher sPLA2-V levels were directly associated with faster artery thrombosis.

CONCLUSIONS

sPLA2-V plays a thrombogenic role by impairing the ability of EPCR to promote protein C activation.

[Role of CFH and ARMS2 polymorphisms in retinopathy and coronary artery disease in type 1 diabetes]

BACKGROUND

Type 1 diabetes is associated with vascular morbidity. The aim of this study was to evaluate the role of polymorphisms rs1410996 CFH and rs10490924 ARMS2 with proliferative diabetic retinopathy and coronary disease in type 1 diabetes patients.

MATERIAL AND METHODS

We present a retrospective study that analyses the clinical characteristics and the polymorphisms rs1410996 CFH and rs10490924 ARMS2 of 147 type 1 diabetes patients.

RESULTS

The patients who developed proliferative diabetic retinopathy in the first 20 years carried the rs1410996 CFH polymorphism. The overall risk-allele frequency was significantly higher among patients with coronary artery disease than in those without it (75 vs. 53%, p<0.001).

CONCLUSIONS

rs1410996 CFH polymorphism could be associated with both proliferative diabetic retinopathy and coronary artery disease in type 1 diabetes patients. However, rs10490924 ARMS2 does not seem to be associated either with retinopathy or coronary artery disease.

[Genetic predisposition to bleeding during oral anticoagulants treatment]

The degree of anticoagulation obtained during oral anticoagulation therapy with vitamin K antagonists (VKA) varies among patients due to individual and environmental factors. The rate of anticoagulation influences the hemorrhagic risk. Therefore, it is plausible that patients specially sensitive to oral anticoagulants are at higher hemorrhagic risk, specially during the first weeks. The role of a series of polymorphisms of the enzymes involved in the metabolism of VKA or in the vitamin K cycle are reviewed. Three polymorphisms, two in the cytochrome P450 2C9 and one in the VKORC1 enzyme, are responsible for a high portion of the variability observed in the sensitivity to AVK. Although the available literature suggests that these genetic variants could increase the risk of severe hemorrhage, larger, well designed studies are needed to confirm this notion.

Binding of factor VIIa to the endothelial cell protein C receptor reduces its coagulant activity

BACKGROUND

Endothelial cell protein C receptor (EPCR) binds protein C through its gamma-carboxyglutamic acid (Gla) domain and enhances its thrombin-thrombomodulin complex-dependent activation. So far, only protein C/activated protein C has been shown to interact with EPCR. Factor VII (FVII), the coagulation trigger upon tissue factor (TF) interaction, is a serine protease whose Gla domain is highly homologous to the Gla domain of protein C.

OBJECTIVES

To characterize the binding of FVII/FVIIa to EPCR and its functional consequences.

METHODS AND RESULTS

We demonstrated by surface plasmon resonance (SPR) that FVII/FVIIa binds to EPCR through its Gla domain. At therapeutic concentrations, FVIIa reduced the activation of protein C by 40%. Soluble EPCR (sEPCR) was also able to prolong dose-dependently the clotting time induced by the FVIIa-TF complex. SPR and amidolytic experiments showed that FVIIa is able to interact simultaneously with TF and EPCR, thus ruling out the possibility that the effect of EPCR on clotting time was due to the inhibition of the binding between FVIIa and TF. sEPCR inhibited dose-dependently the activation of FX by the FVIIa-TF complex. Notably, blocking the binding site of EPCR on the endothelial surface increased the generation of FXa 2-fold.

CONCLUSIONS

EPCR binds to FVII/FVIIa and inhibits the procoagulant activity of the FVIIa-TF complex.

Autoantibodies against endothelial protein C receptor and the risk of a first deep vein thrombosis

BACKGROUND

The endothelial protein C receptor (EPCR) binds protein C and enhances its activation. Anti-EPCR autoantibodies are found in patients with antiphospholipid syndrome and may explain the increased risk of thrombosis in these patients. Anti-EPCR autoantibodies have been associated with fetal death and myocardial infarction in young women.

OBJECTIVES

To determine whether anti-EPCR autoantibodies are associated with deep vein thrombosis (DVT).

PATIENTS/METHODS

We measured plasma anti-EPCR autoantibody levels in the Leiden Thrombophilia Study (LETS), a population-based case-control study consisting of 474 patients with a first DVT and 474 control subjects.

RESULTS

The estimated risk of DVT was increased approximately 2-fold in the presence of elevated IgA, IgG or IgM anti-EPCR autoantibodies (i.e. levels above the 90th percentile as measured in the control subjects). The risk conferred by anti-EPCR increased in a dose-dependent manner for IgA and IgG. When anti-EPCR autoantibodies were considered in the co-presence of lupus anticoagulant (LAC) the odds ratio (OR) was 6.1 [95% CI 1.3-27.9]. Anti-EPCR without LAC remained associated with DVT (OR 1.6; 95% CI 1.2-2.1). Anti-EPCR autoantibodies were associated with high levels of D-dimer and soluble EPCR in controls, suggestive of a prothrombotic status induced by the autoantibodies.

CONCLUSIONS

This study demonstrates that the presence of anti-EPCR autoantibodies is a moderate risk factor for DVT in the general population.

Association of increased fibrinogen concentration with impaired activation of anticoagulant protein C

BACKGROUND

Low levels of activated protein C (APC) are a risk factor for venous thrombosis. The mechanisms leading to interindividual differences in APC are not totally elucidated. Protein C is activated by the thrombin-thrombomodulin complex. As thrombin binds to fibrinogen and thrombomodulin through a common region, it is conceivable that fibrinogen influences the activation of protein C. This would help to explain the association between high levels of fibrinogen and an increased thrombotic risk.

METHODS

We analyzed the association between circulating APC levels and fibrinogen concentration in 382 healthy subjects. Subsequently, we studied the effect of increasing fibrinogen concentrations on the APC generation on cultured endothelial cells.

RESULTS

An independent inverse association between circulating APC levels and fibrinogen was found [betacoefficient, -0.16; 95% confidence interval (95% CI) -0.26, -0.06; P = 0.001]. For each 100 mg dL(-1) increase in fibrinogen, the independent risk of having low APC levels (<0.7 ng mL(-1)) was almost three times higher (OR 2.8; 95% CI 1.1, 7.2; P = 0.04). Accordingly, a notable association between increasing fibrinogen concentrations and the reduction in the thrombin-thrombomodulin dependent activation of protein C on endothelial cells was found (r = -0.57; P = 0.002).

CONCLUSIONS

We present evidence of an inverse association between circulating APC and fibrinogen levels. According to this finding together with the results of our in vitro experiments, we propose that the impairment in the generation of APC on endothelial cells constitutes a new prothrombotic mechanism of fibrinogen.

Autoantibodies against the endothelial receptor of protein C are associated with acute myocardial infarction in young women

BACKGROUND

Acute myocardial infarction (AMI) is rare among young women. The search for unknown risk factors is warranted. Endothelial protein C receptor (EPCR) is largely present at the endothelial surface of large arteries. No studies about association of anti-EPCR autoantibodies (anti-EPCR) with AMI are available.

METHODS

Plasma IgA, IgM and IgG anti-EPCR levels were measured by enzyme-linked immunosorbent assay in 165 women younger than 45 years who survived a first AMI and 165 healthy women, matched by age and geographical origin.

RESULTS

Using the 90th percentile of IgA anti-EPCR in the control group, IgA anti-EPCR were independently associated with AMI after adjustment for cardiovascular risk factors (OR 5.1; 95% CI 1.7-15.6; P = 0.004). The risk apparently conferred by IgA anti-EPCR increased dose-dependently (P for trend =0.0002). IgM anti-EPCR were less consistently associated with AMI: a significant increase in the risk was found when women above the 90th percentile were compared with those in the lowest quartile (OR 3.6; 95% CI 1.2-11.5; P = 0.03). IgG anti-EPCR were similar in patients and controls. A total of 145 patients underwent coronary arteriography. IgA or IgM anti-EPCR were not different among patients with different degrees of atherosclerotic lesion (anova, P = 0.77 and 0.24, respectively).

CONCLUSIONS

High levels of IgA and, to a lesser extent, IgM anti-EPCR, are associated with AMI in young women.

Serum cystatin C-immunoglobulin high-molecular-weight complexes in kidney and liver transplant patients

BACKGROUND

It has been suggested recently that the glomerular filtration rate (GFR) in renal transplant patients is underestimated by serum cystatin C due to an impaired filtration of complexed cystatin C with immunoglobulins. Consequently, serum cystatin C may not be a reliable marker of GFR in these patients. Our study was designed to determine whether this supposition is correct.

METHODS

In 87 serum samples from patients with various kidney diseases, 182 samples from renal transplant patients, and 72 samples from liver transplant patients, the concentrations of cystatin C and creatinine were determined, as well as the residual concentration of cystatin C after precipitation of macromolecules with polyethylene glycol (PEG; 6000 molecular weight).

RESULTS

The residual concentration of serum cystatin C after precipitation with PEG in all cases was much higher (70 to 100%) than that expected in the case of the existence of cystatin C-immunoglobulin complexes. In the kidney and liver transplant patients, there was no significant correlation between the residual concentration of cystatin C and the postoperative time (r = -0.098).

CONCLUSIONS

The results suggest that in renal or liver transplant patients there is no formation of high molecular weight serum cystatin C-immunoglobulin complexes, regardless of the post-transplant period.

[Acute interstitial pneumonia: favorable outcome with steroid therapy]

We report the case of a 65-year-old man with no history of respiratory disease who came to the emergency room complaining of fever, cough, yellowish sputum and increasing dyspnea of one week's duration. Severe respiratory insufficiency was evident upon examination and a chest film showed diffuse pulmonary infiltrates. Microbiological tests were negative. Lung biopsy gave evidence consistent with diffuse alveolar damage in organizing phase. Evolution of symptoms and blood gases was good after corticosteroid treatment was begun, although pulmonary fibrosis was still evident in a follow-up radiograph.

Haemostatic genetic risk factors in arterial thrombosis

Haemostasis plays an integral role in arterial thrombotic disease. However, establishing which of the factors are risk factors has proven surprisingly difficult. Because of its technical simplicity and digital nature, the study of haemostatic polymorphisms as risk factors has grown in popularity. Once established as a risk factor, a genetic polymorphism has the potential to aid selective prophylaxis and therapy of disease. Numerous reports have now been published on polymorphisms of coagulation and fibrinolytic factors, of coagulation and fibrinolytic inhibitory proteins, and of platelet membrane glycoprotein receptors. This article describes the polymorphisms and evaluates the results of these studies using the premises of consistency of within-report genotype/phenotype/disease relationships and consistency of outcome between studies. Many studies have been only of association between polymorphisms and disease, a type of study that is prone to error. Furthermore, the collective outcome of these studies has primarily been inconsistent. It is concluded that despite the early promise of polymorphisms as risk factors, fresh approaches differing in scale and design are now required to clarify their possible importance.

Prevention of renal fibrin deposition in endotoxin-induced DIC through inhibition of PAI-1

Plasminogen activator inhibitor-1 (PAI-1) increases in endotoxemia thus possibly cooperating in altering the hemostatic balance in a prothrombotic direction. The effect of the inhibition of PAI-1 with the monoclonal antibody MA-33B8 was studied systemically and in kidneys in a lapine model of endotoxin-induced disseminated intravascular coagulation (DIC). The increase in plasmatic PAI activity in the control group (n = 9) was inhibited in the MA-33B8 treated rabbits (n = 5). Control rabbits showed renal fibrin deposits, whereas only one of the MA-33B8 rabbits did so. These results were confirmed immunohistochemically in kidneys as PAI-1 immunostaining was seen inside the glomeruli and larger vessels in the control group, whereas MA-33B8 rabbits showed a remarkable decrease, demonstrating that MA-33B8 successfully inhibited PAI-1 in the kidneys as well. Therefore evidence for the important role of PAI-1 in fibrin generation in endotoxin-induced DIC is presented, suggesting that strategies aiming at its reduction can be useful in this pathology.

Comparison of predose vs 2-h postdose blood metabolites/cyclosporine ratios in kidney and liver transplant patients

OBJECTIVES

It has recently been suggested that when adjusting doses of cyclosporine (CsA), determining its concentration in blood samples taken 2 h postdose (C(2)) is more clinically beneficial than using the predose concentration (C(0)). We determined C(0) and C(2) concentrations of CsA and their metabolites in samples taken from nine kidney and seven liver transplant patients. Similarly, the so-called metabolic ratios (MR)-metabolites to CsA parent ratios-were calculated to characterise the most suitable moment of blood sampling for obtaining a greater analytical specificity with monoclonal immunoassays.

METHODS

The determination of CsA and CsA + metabolites was made using the enzyme multiplied immunotechnique and the polyclonal fluorescence polarization immunoassay Abbott TDx, respectively.

RESULTS

The poor correlation between C(0) and C(2) of CsA (n = 82, r = 0.387, p < 0.001) is greatly inferior to that obtained between C(0) and C(2) of metabolites (n = 82, r = 0.912, p < 0.001). A highly significant difference (p < 0.001) was found between MR(0) values (mean 2.87 +/- 0.12, median 2.48) and MR(2) values (mean 1.73 +/- 0.09, median 1.46), although there is a good correlation between them (r = 0.878, p < 0.001).

CONCLUSIONS

The extent of the positive bias (deviation) of CsA immunoassays compared with the high-performance liquid chromatography results is related to the MR values. As the MR(2) values are significantly lower than the corresponding MR(0), in practice a greater analytical specificity would be obtained with the different monoclonal immunoassays in the determination of the 2 h postdose CsA concentration than in that of trough concentration.

Type II protein C deficiency: identification and molecular modelling of two natural mutants with low anticoagulant and normal amidolytic activity

Two mutations in exons 3 and 9 of the protein C gene were identified by amplification and sequencing from symptomatic probands referred for venous thromboembolism and thrombophilia screening. The phenotype associated with the mutations is a type II protein C deficiency with normal amidolytic activity. In one family, the mutation in exon 3 (G3545-->A), which predicts an R9 to H substitution in the Gla domain, was identified. A mutation in exon 9 (G10899-->A), which predicts an R352 to W substitution in the catalytic site, was identified in the second family and has been reported previously in association with type II deficiency with low amidolytic activity. Western blotting of the purified proteins from the probands' plasma did not show any abnormal migratory pattern. Molecular modelling suggested a possible impairment in the recently described Na+ binding pocket for the R352-->W mutant. No conclusions could be drawn relative to the R9-->H mutant.

Poor relationship between phenotypes of protein S deficiency and mutations in the protein S alpha gene

By single strand conformational polymorphism, nucleotide sequencing and enzyme restriction, we analyzed the protein S alpha gene in 17 protein S-deficient probands and in their available family members. The relationship between genotype and phenotype was also evaluated. Twelve different sequence variations were identified in 17 probands. Ten were putative causal mutations distributed in 16 probands: 4 were nonsense, 5 missense and one a splice site mutation. In most families in which a mutation was identified, more than one phenotype of PS deficiency was present. The same splice site mutation (intron j G-A, exon 10+5) was associated with type I deficiency in one family and with type I/III in another unrelated family. A phenotypic discrepancy was also observed for the Arg474Pro, Gly597Asp and Arg410stop mutations. Glu26Ala, previously reported in kindreds with type I deficiencies, was found in association with I, II and III phenotypes in four unrelated kindreds. Phenotypic analysis of protein S deficiency is poorly related to the underlying genetic defect.

Comparative validity of three methods for assessment of the quality of primary health care

OBJECTIVE

This study compared the sensitivity and specificity of three assessment methods to detect the performance of key clinical tasks by health workers in a primary care setting.

DESIGN

Health worker performance during patient encounters for acute respiratory infections, acute diarrhea and family planning counseling was assessed through checklist-based observation of the consultation, interview with the mother following the consultation, and review of the patient's clinical record. The results of each method regarding the performance of key tasks by health workers were compared to a 'gold standard', defined as the application of the observation checklist by observers with extensive quality assessment experience. Patient encounters were studied in three Ministry of Health facilities in the Department of Totonicapán, Guatemala, involving care by physicians, nurses and auxiliary staff

RESULTS

The three methods showed reasonably high levels of sensitivity (generally about 70%) for the detection of failures in the performance of most health worker tasks. The greatest problem experienced by each method related to specificity, i.e. capacity to recognize quality successes and only detect real failures.

CONCLUSION

Direct observation demonstrated the best overall balance of sensitivity and specificity. Exit interview of the mother demonstrated good sensitivity and better specificity than record review.

Effect of the administration of recombinant hirudin and/or tissue-plasminogen activator (t-PA) on endotoxin-induced disseminated intravascular coagulation model in rabbits

We evaluated the effect of r-hirudin and/or tissue-plasminogen activator (t-PA) in a model of DIC in rabbits induced by i.v. infusion of 100 micrograms/kg/h/6 h endotoxin. Rabbits were treated with saline (endotoxin control group), r-hirudin at 0.3 mg/kg/h/6 h, t-PA at 0.3 mg/kg for 90 min and r-hirudin plus t-PA at the doses described above. The best results were achieved when r-hirudin and t-PA were infused together. This treatment reduced the consumption of platelets and protein C and attenuated the increase of PAI-1 more efficiently than r-hirudin or t-PA alone. r-Hirudin plus t-PA also resulted in the lowest formation of fibrin deposits in the kidneys. Finally, mortality at 24 h dropped from 70% in the endotoxin control group to 40%, 10% and 0% in the t-PA, r-hirudin and r-hirudin plus t-PA groups respectively. None of the t-PA-infused rabbits which had died by 24 h showed macroscopic signs of haemorrhage. r-Hirudin alone was better than t-PA alone, as was shown by fibrin deposits and mortality. We conclude that r-hirudin and t-PA given simultaneously were more efficient than either given alone in this model of DIC. Effective thrombin inhibition, which could influence other pathophysiological mechanisms apart from coagulation, together with the improvement in fibrinolysis, would explain these results.

Effects of low molecular weight heparin, alone or combined with antithrombin III, on mortality, fibrin deposits and hemostatic parameters in endotoxin-induced disseminated intravascular coagulation in rabbits

The effect of low molecular weight heparin (LMWH) with or without antithrombin III (AT III) has been studied in a rabbit model of disseminated intravascular coagulation (DIC) induced by continuous infusion of 100 microg/kg/hr of Escherichia coli endotoxin for 6 hr. LMWH (5 and 10 IU/kg/hr/6 hr), alone or in combination with AT III (20 U/kg/hr/6 hr), or saline were administered simultaneously with endotoxin. Hemostatic markers at 0, 2, and 6 hr as well as kidney fibrin deposits and the mortality rate at 24 hr were determined. Rabbits receiving only endotoxin showed an impairment in hemostasis, as well as high kidney fibrin deposits and a high mortality rate. LMWH alone did not exert any effect. The simultaneous infusion of LMWH and AT III exerted a beneficial effect on the hemostatic markers and reduced the kidney fibrin deposits as well as the mortality rate in a LMWH dose-dependent manner. Fibrinogen and protein C consumption were significantly higher and renal fibrin deposits more intense in the rabbits that had died in the first 24 hr. There was also a significant positive correlation between kidney fibrin deposits and platelets, fibrinogen, and protein C consumption, taking the whole rabbit population. It is concluded that the simultaneous infusion of LMWH and AT III is useful in this DIC model and would make it possible to reduce significantly the AT III doses used when AT III is given alone.

Endotoxin-induced disseminated intravascular coagulation in rabbits: effect of recombinant hirudin on hemostatic parameters, fibrin deposits, and mortality

We evaluated the effect of r-hirudin on an experimental model of disseminated intravascular coagulation (DIC) in rabbits, through the continuous infusion of 100 microg/kg/hr of Escherichia coli endotoxin for a period of 6 hours. r-Hirudin (0.05, 0.3, and 0.6 mg/kg/hr) as treatment, or saline solution as placebo, were administered simultaneously with endotoxin. Severe DIC in the endotoxin control group was shown by impairment in hemostatic parameters, kidney fibrin deposition, and a high mortality rate. Medium and high doses of r-hirudin led to an improvement in such DIC-related parameters as platelet numbers and fibrinogen and protein C concentrations. High-dose r-hirudin also reduced consumption of antithrombin III (ATIII). All doses of r-hirudin prevented decreases in tissue plasminogen activator (t-PA) and reduced the increase in plasminogen activator inhibitor-1 (PAI-1) activity observed at 2 hours after endotoxin administration. A significant reduction in kidney fibrin deposition was seen in medium- and high-dose r-hirudin groups. Additionally, the mortality rate in rabbits receiving medium- and high-dose r-hirudin was 10%, and that in rabbits receiving low-dose r-hirudin was 20%, as compared with a mortality rate of 70% in the control group. Protein C activity was significantly lower (p < 0.001) in nonsurviving rabbits. Moreover, there was a strong positive correlation (r = 0.68, p < 0.001) between protein C consumption and kidney fibrin deposition. We conclude that r-hirudin can be a useful drug in the clinical treatment of DIC.

Reducing patient waiting times through quality assurance methods in La Troncal, Ecuador

Long patient waiting time is a common problem in hospitals and urban health centers in Ecuador and elsewhere. Besides being a leading cause of patient dissatisfaction with health service quality, it is often related to short doctor-patient contact times that in turn can seriously reduce the technical quality of care. This article describes a quality improvement effort undertaken by the staff of the La Troncal Health Center in Ecuador, with the assistance of a quality assurance project of the University Research Corporation and the Ecuadorian Ministry of Health. Data on patient waiting times was collected and analyzed, and solutions were devised and implemented using quality assurance techniques. As a result, the average patient's total waiting time fell from 116 minutes per visit to 66, and his or her contact time with health center staff members increased from 11 minutes to 16. It appears that the methods and techniques applied have potential for use elsewhere, because they can be applied easily by health personnel, and their cost of implementation is relatively low.