Presentation on theme: "Neuroprotection Provided by Local Administration of Low- Dose Cold Albumin in Acute Ischemic Stroke Vance Fredrickson Wayne State University School of."— Presentation transcript:
Neuroprotection Provided by Local Administration of Low- Dose Cold Albumin in Acute Ischemic Stroke Vance Fredrickson Wayne State University School of Medicine
Albumin – functions in plasma Major protein (t1/2 ~ 20 days) Creates 80% of the colloid oncotic pressure Transporter of endogenous substances ◦fatty acids ◦Unconjugated bilirubin ◦Hormones Main drug binding protein Buffers pH
Clinical Uses (widespread consensus for use) Paracentesis ◦infused after volumes of >5 L removed Therapeutic Plasmapheresis ◦Infused after exchanges of > 20 mL/kg Spontaneous bacterial peritonitis ◦In association with antibiotics
Albumin in Acute Ischemic Stroke (animal studies – with systemic administration ) Neuroprotective properties (25% Alb, 1.25 – 2.5 g/kg) ◦Improved neurological scores ◦Decreased infarction size ◦Reduced brain swelling ◦Improved cerebral perfusion ◦Normalizes changes seen on MRI Therapeutic window: 4-5 hours
Possible Mechanisms of Neuroprotection Increase in plasma oncotic pressure Increase pyruvate dehydrogenase in astrocytes ◦ increase flux of glucose and lactate Maintenance of normal vascular permeability Inhibition of endothelial cell apoptosis
Clinical Trials (systemic Albumin administration) ALIAS Pilot Trial (0.34-2.05 g/kg) ◦Pulmonary Edema (dose-dependent) 16.7 % in patients receiving 1.03 g/kg Alb 27.8 % in patients receiving 1.37 g/kg Alb ALIAS Part 1 Trial (2 g/kg) ◦Pulmonary edema 3-higher in Alb treated group compared to control ◦Suspended due to safety concerns
Clinical Trial (systemic Albumin administration) ALIAS Part 2 Trial (2 g/kg systemic Alb) ◦Additional measures taken Require normal baseline serum troponin Restriction of IV fluids Mandatory diuretics ◦Trial in progress ◦Will likely restrict the number of patients receiving therapy
Questions Addressed in our Animal Model of Acute Ischemic Stroke Can a local low-dose albumin infusion provide similar neuroprotection as systemic high-dose? Does a local low-dose cold albumin infusion provide additional benefit?
Experiment Design 64 Male Sprague-Dawley rats MCA occlusion induced by a modified microcatheter (2 hr occlusion) Local infusion treatment groups ◦Catheter withdrawn 1-2 mm for reperfusion and treatment infusion was begun Systemic infusion treatment groups ◦Catheter withdrawn completely and albumin administered via femoral artery Infused volumes 2.5 mL
Experimental Groups Non-treatment group (n=8) ◦2 hr MCA occlusion followed by 48 hours of reperfusion Local Infusion Groups ◦cold (0°C) saline (0.9% NS, n=12) ◦low-dose cold (0°C) human Alb (0.5 g/kg, n=12) ◦low-dose normothermic (37°C) human Alb (0.5 g/kg, n=12) Systemic Infusion Groups ◦low-dose normothermic (37°C) human Alb (0.5 g/kg, n=8) ◦high-dose normothermic (37°C) human Alb (1.5 g/kg, n=12)
Results - Hypothermia (local cold saline and cold Alb infusion groups) Hypothermia induced in less than 3 mins Cerebral cortex (region supplied by the MCA) ◦37.2 ± 0.2 0 C to 30.5 ± 0.4 0 C Striatum ◦37.8 ± 0.1 0 C to 30.8 ± 0.4 0 C Temperatures remained reduced for up to 45 mins.
Results – Lesion Volume Local low-dose cold albumin results in smallest lesion volume.
Results – Lesion Volume Local low-dose Alb provides a similar reduction in lesion volume as systemic high-dose Alb
Results – Neurological Exam Local low-dose cold Alb treatment results in strongest reduction in deficits according to neurological exam
Results – Neurological Exam Local low-dose and systemic high-dose Alb treatments resulted in similar improvement in neurological exam
Summary Local low-dose and systemic high-dose Alb provide similar neuroprotection Synergistic effect of regional brain hypothermia and local low-dose Alb administration This protocol combined with tPA or mechanical embolectomy, may be of benefit in the clinical setting.
References Belayev L, Liu Y, Zhao W, Busto R, Ginsberg MD. Human albumin therapy of acute ischemic stroke: Marked neuroprotective efficacy at moderate doses and with a broad therapeutic window. Stroke; a journal of cerebral circulation. 2001;32:553-560 Ginsberg MD, Hill MD, Palesch YY, Ryckborst KJ, Tamariz D. The alias pilot trial: A dose-escalation and safety study of albumin therapy for acute ischemic stroke--i: Physiological responses and safety results. Stroke; a journal of cerebral circulation. 2006;37:2100-2106 Palesch YY, Hill MD, Ryckborst KJ, Tamariz D, Ginsberg MD. The alias pilot trial: A dose-escalation and safety study of albumin therapy for acute ischemic stroke--ii: Neurologic outcome and efficacy analysis. Stroke; a journal of cerebral circulation. 2006;37:2107-2114 Ginsberg MD, Palesch YY, Martin RH, Hill MD, Moy CS, Waldman BD, et al. The albumin in acute stroke (alias) multicenter clinical trial: Safety analysis of part 1 and rationale and design of part 2. Stroke; a journal of cerebral circulation. 2011;42:119-127 Liumbruno G, Bennardello F, Lattanzio A, et al. Recommendations for the use of albumin and immunoglobulins. Blood Transfus. 2009;7:216–34.