Thrombolytic properties of leukocytes from peripheral blood in healthy subjects and in patients with acute cerebral ischemia

Comparative study of intravenous thrombolysis with rt-PA and urokinase for patients with acute cerebral infarction

Objective

Cerebral infarction has a poor prognosis and causes a serious burden on families and society. Recombinant tissue plasminogen activator (rt-PA) and urokinase (UK) are commonly used thrombolytic agents in the clinic. However, direct and powerful clinical trial evidence to determine the therapeutic effect of rt-PA and UK on intravenous thrombolysis is lacking.

Methods

In this study, 180 patients with acute cerebral infarction were treated with rt-PA or UK. The National Institutes of Health Stroke Scale (NIHSS) scores, Barthel index, bleeding complications, and biomarkers were evaluated.

Results

No significant differences in NIHSS or Barthel scores were found between the groups. However, UK increased the risk of intracranial haemorrhage compared with rt-PA. rt-PA had increased activity in reducing serum levels of MMP-9 than UK.

Conclusion

Intravenous thrombolysis with rt-PA and UK in the time window of acute cerebral infarction can achieve similar therapeutic effects, but rt-PA can further reduce the risk of cerebral haemorrhage and is relatively safer than UK.

The association baseline NIH Stroke Scale score with ABO blood-subtypes in young patients with acute ischemic stroke

OBJECTIVES

The presence of the A and B blood group antigens has been associated with risk of arterial thrombosis. The aim of the current study was to design a new simpler form of National Institutes of Health Stroke Scale (NIHSS) for use on admission, and assess the association of blood groups with NIHSS score in young stroke patients.

METHODS

We conducted this study in 1311 young Chinese adults with acute ischemic cerebral stroke. The outcome measures included a composite favorable outcome (defined as a modified Rankin Scale (mRS) of 0 or 2) and poor outcome (defined as a modified Rankin Scale score of 3 or 6) at discharge; a minor strokes (NIHSS scores 0-5) and severe strokes (NIHSS scores ≥6). Logistic regression analyses were used to determine the association between ABO blood groups and stroke severity.

RESULTS

Regression analysis confirmed in relative to patients with AB subtype, Oxfordshire community stroke project classification (OCSP) subtype and serum white blood cell (WBC) were the major predictors for stroke severity. Meanwhile, diabetes, serum triglyceride and uric acid levels were determined as independent indicators of stroke severity in A, B and O blood subtype respectively. The optimal cutoff score of the baseline NIHSS was ≤5 for patients with non-O subtype, the optimal cutoff score of the baseline NIHSS was ≤7 for patients with blood O subtype.

CONCLUSIONS

Our analysis provide compelling information regarding the ABO blood groups differences in predictors of stroke severity and the different validity of NIHSS scores in predicting prognosis at discharge between O subtype and non-O subtype.

Leukocytes may have 2 opposing effects in intravenous rtPA treatment for ischemic stroke

We hypothesized that leukocytes have 2 opposing effects on patients with ischemic stroke treated with recombinant tissue plasminogen activator (rtPA). Patients with ischemic stroke treated with rtPA were divided into 2 groups using the peripheral leukocyte count: high leukocyte group (HLG) and low leukocyte group (LLG) and were evaluated with the National Institutes of Health stroke scale (NIHSS) during the first 24 hours. We defined significant improvement (SI) as NIHSS improving by more than 50% from the baseline, and deterioration following improvement (DFI) as the achievement of SI within 24 hours but its subsequent loss at 24 hours. Fifty-three patients were enrolled, and the rate of SI within 24 hours was higher in HLG than in LLG (85.2% vs 42.3%, P = .0011). However, the rate of DFI was significantly higher in HLG than in LLG (29.6% vs 7.7%, P = .0413). We found that leukocytes might have not only deleterious but also beneficial effects in intravenous rtPA treatment.

An animal model for venous thrombosis and spontaneous pulmonary embolism

STUDY DESIGN

An animal model.

OBJECTIVE

To test the natural sequence of venous thrombosis and pulmonary thromboembolism experimentally.

SETTING

Veterans Administration Hospital, USA.

METHOD

In dogs, a venous thrombosis was induced in a isolated segment of the internal jugular vein by a 5 min exposure to sodium morrhuate and then re-establishing venous patency. A tracer, (125)I human fibrinogen, was administered through another vein 1 h prior to the end of each experiment when a blood sample, the venous thrombus, and the lungs were removed. Thrombi were described by age, weight, histology, and fibrin uptake (thrombus to blood radioactivity ratio, g/g). Pulmonary emboli (PE) were identified by autoradiography of lung slices or by microscopic examination of lung sections.

RESULTS

Venous thrombosis developed in all experiments, duration 1-64, median 5 h (n=12). Histologically, younger thrombi were characterized by platelet aggregates surrounded by polymorphonuclear leukocytes (PMN), and uniform fibrin deposit; the older thrombi by platelet ghost cells, fewer PMN leukocytes, and broken fibrin strands and loops (n=6). Pulmonary thromboemboli were imaged as 'hot spots' in six of six experiments in which lung slices were autoradiographed and were identified microscopically in six of six experiments in which lung sections were taken. The number of PE diagnosed microscopically did not correlate with the age of the corresponding thrombus but was directly related to fibrin uptake (n=5, r=0.99, P<0.01).

CONCLUSION

An animal model for venous thrombosis that generates pulmonary thromboembolism has been described.