Cuantificación de la inmunoglobulina G y la albúmina en el líquido cefalorraquídeo mediante las modificaciones de las técnicas para otros fluidos biológicos

To evaluate the results of estimating the functional status of blood–cerebrospinal fluid barrier (B–CSFB) and intrathecal immunoglobulin synthesis (ITS) of IgG for central nervous system by modified commercial techniques designed for other biological fluids. Methods: Disc polyacrylamide gel electrophoresis and quantification of CSF total protein in CSF and serum of 61 patients were conducted at the Institute of Neurology and Neurosurgery (INN) between April and September 2014. The concentration of albumin and IgG was determined by commercial standardized techniques and by modifications of commercial techniques. Albumin ratio and IgG index were calculated and employed to evaluate B–CSFB permeability and ITS, respectively. Results: Total protein and protein electrophoresis patterns were correlated with the quantifications performed by modified commercial techniques. There was no significant difference between validated commercial techniques and modified techniques for quantifications of CSF albumin (Z=0,41; p=0,6791), serum albumin (Z=0,08; p=0,9382), Qalb (Z=0,21; p=0,8361), CSF IgG (Z=1,65; p=0,0995) and IgG index (Z=1,10; p=0,2721). Conclusions: The immunological studies in CSF obtained from modifying commercial techniques designed for other biological fluids are useful to estimate the functionality of B–CSFB and intrathecal immunoglobulin synthesis. The modifications carried out for the turbidimetric technique and for the UMELISA kit should be standardized for the validation of BCSF–B permeability and IgG ITS by the nervous system.OBJETIVO: Evaluar los resultados de la estimación del estado funcional de la barrera sangre–líquido cefalorraquídeo (LCR) y la síntesis intratecal de inmunoglobulina G (IgG) por el sistema nervioso central mediante las modificaciones de las técnicas comerciales diseñadas para otros fluidos biológicos.MÉTODOS: A muestras de LCR y suero de 61 pacientes se les realizaron electroforesis de disco en geles de poliacrilamida y cuantificación de proteínas totales (PT) en el Instituto de Neurología y Neurocirugía, Habana, Cuba (INN), entre los meses de abril y diciembre de 2014. Se determino las concentraciones de albúmina e IgG empleando paralelamente técnicas comerciales modificadas en el laboratorio y métodos validados para estos estudios. Se calculó el cociente albúmina (Qalb) y el índice IgG, como indicadores del estado funcional de la barrera sangre–LCR y de la síntesis intratecal (SIT), respectivamente.RESULTADOS: Las PT y los patrones de electroforesis se correlacionaron con el Qalb y albúmina, realizado por las técnicas modificadas. No se encontraron diferencias significativas entre las cuantificaciones de las técnicas validadas y modificadas para los valores de albúmina en LCR (Z=0,41; p=0,6791), albúmina en suero (Z=0,08; p=0,9382), el Qalb (Z=0,21; p=0,8361), IgG en LCR (Z=1,65; p=0,0995) e índice IgG (Z=1,10; p=0,2721).CONCLUSIONES: Se demuestra que estas modificaciones en técnicas comerciales diseñadas para otros fluidos bilógicos resultan útiles para estimar la funcionalidad de la BS–LCR y calcular la SIT de inmunoglobulinas. Las modificaciones introducidas a la técnica turbidimétrica y al UMELISA pueden ser estandarizadas para su validación en el diagnóstico de daño de la BS–LCR y de síntesis intratecal de IgG por el sistema nervioso

Cerebral Small Vessel Disease Associated with Subclinical Vascular Damage Indicators in Asymptomatic Hypertensive Patients

Background: Cerebral small vessel disease (CSVD) is frequent in patients with cardiovascular risk factors including arterial hypertension, and it is associated with vascular damage in other organs and the risk of stroke, cognitive impairment, and dementia. Early diagnosis of CSVD could prevent deleterious consequences. Objective: To characterize CSVD associated with indicators of subclinical vascular damage in asymptomatic hypertensive patients. Materials and Methods: Participants were hypertensive (HT) and non-hypertensive (non-HT) individuals; without signs of cerebrovascular disease, dementia, and chronic renal failure. For CSVD, white matter hyperintensities (WMH), enlarged Virchow–Robin perivascular spaces (EVRPS), lacunar infarcts, and microbleeds were investigated. Subclinical vascular damage was evaluated (hypertensive retinopathy, microalbuminuria, and extracranial carotid morphology: intima media thickness (IMT) and atheroma plaque). Results: CSVD MRI findings were more frequent in HT; as well as greater intimal thickening. The IMT and/or plaque was significantly associated with all MRI variables; but retinopathy was correlated with EVRPS and lacunar infarcts. Only microalbuminuria was related to the greater severity of WMH in HT. Multivariate analysis evidenced that CSVD was independently associated with the combination of indicators of vascular damage and systolic blood pressure. Conclusions: Combining indicators of subclinical vascular damage, such as carotid morphological variables, microalbuminuria, and hypertensive retinopathy for early detection of CSVD in asymptomatic hypertensive patients could prove to be useful to take actions for the prevention of irreversible brain damage, which could lead to cognitive impairment, dementia and stroke