Determination of serum visinin like protein-1 and its potential for the diagnosis of brain injury due to the stroke - a pilot study

Abstract

Background. The current diagnosis of stroke relies on clinical examination by a physician supplemented by various neuroimaging techniques. A single set or multiple sets of blood biomarkers that could be used in acute settings to diagnosis stroke, differentiate between stroke types, and ideally predict an initial/recurring stroke would be extremely valuable. The diagnosis of stroke is currently hampered by delay due to lack of a suitable tool for rapid, accurate and analytically sensitive biomarker - based testing. There is a clear need for further assay development and clinical validation in this area (acute stroke setting) in order to improve patient outcomes and quality of life. Visinin like protein 1 (VILIP-1) is a newly discovered CNS-abundant protein which has shown promise in experimental studies, for early stroke diagnosis. However, to date there is no clinical study that has measured VILIP-1 in sera as a marker of stroke. Aim. To develop an assay for the determination of VILIP-1 in human serum, and to investigate its clinical relevance as a marker of ischemic stroke. Design and methods. A new sandwich ELISA was developed, introduced and clinically tested. Mean spiking recovery was 98%. The mean recovery for dilution linearity was 93%. The limit of detection of the assay was 0.01 mcg/l; the intraassay and interassay coefficient of variation (CV) were always less than 10%. The study was approved by the Ethics Commission of the Hospital Šternberk, Czech Republic. A total of 17 healthy individuals (9 men and 8 women, age 64.0 ± 13.0) and 16 individuals with ischemic stroke (10 men and 6 women, age 63.0±11.5) were recruited for our study. The criteria of stroke were proposed by the National Czech Standard. All individuals had blood samples drawn, and VILIP-1 analysis and CT and/or MRI were performed. Results. VILIP-1 serum level significantly differentiated healthy subjects from patients with stroke (P<0.01). All individuals with stroke had VILIP-1 serum values higher than > 0.05 mcg/l, healthy had values below this value. The diagnostic efficacy of serum VILIP-1 was very significant (sensitivity 100%, specificity 100% at 0.093 mcg/l VILIP-1 serum values, AUC 1.0 (CI 0.93-1.0, P<0.01), Chi-squared in the frequency table was 33 (P<0.01). Conclusion. We have introduced a new analytical tool for the study of VILIP-1. Our results support the hypothesis that serum VILIP-1 may be associated with ischemic stroke. The ELISA VILIP-1 assay offers a new research tool for the diagnosis and pathophysiology of stroke and other CNS diseases. © D. Stejskal, L. Sporova, M. Svestak, M. Karpisek.