Exame do líquido cefalorraquidiano: Influência da temperatura, tempo e preparo da amostra na estabilidade analítica

Abstract

The cerebrospinal fluid (CSF) is a biological fluid that is in close relation with the central nervous system (CNS). Therefore, the CSF examination constitutes an invaluable method in the diagnosis and monitoring of countless neurological diseases. However, there are a few studies about the stability of its analytes during the pre-analytical stage. Objective: To identify existing data about the influence of temperature and storage time, freezing/thawing cycles and pre-treatments (centrifugation, denaturation, serum addition) on the stability of CSF analytes. Method: A systematic review of articles in the literature was conducted by use of key words in English such as "storage", "cerebrospinal fluid", "CSF", "stability", "temperature" and "period", based on data from PubMed, Highwire Press, Lilacs and Amazonas Library, free digital archives of biomedical research articles. Result: The search found nine articles, what results from the lack of studies about this subject. Different CSF constituents were analyzed: number of cells and their morphology, total protein, glucose, lactate, amino acids, creatine, creatinine, biomarkers and enzymes. The methodologies employed were: optical microscopy, enzyme linked immunosorbent assay (ELISA), Imunoblot/SDS-PAGE and spectrometry. Conclusion: The literature review confirms that the stability of CSF samples is influenced by temperature, storage time and conditions of pre-analytical preparation. The findings of this systematic review may contribute to improving the knowledge about CSF examination, as well as to better understanding the sample stability.