Open AccessEstimation of intrathecal IgG synthesis: simulation of the risk of underestimation
Author(s) -
Bonnan Mickael,
GianoliGuillerme Mariana,
Courtade Henri,
Demasles Stéphanie,
Krim Elsa,
Marasescu Raluca,
Dréau Hervé,
Debeugny Stéphane,
Barroso Bruno
Publication year - 2018
Publication title -
annals of clinical and translational neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.824
H-Index - 42
ISSN - 2328-9503
DOI - 10.1002/acn3.548
Subject(s) - intrathecal , medicine , interpretation (philosophy) , estimation , range (aeronautics) , sample (material) , sample size determination , statistics , surgery , mathematics , chromatography , computer science , chemistry , materials science , management , economics , composite material , programming language
Objective The low level of passively diffused IgG through the blood–brain barrier is sufficient to blur the estimation of intrathecal IgG synthesis ( ITS ). Therefore, this estimation requires a mathematical calculation derived from empirical laws, but the range of normal values in healthy controls is wide enough to prevent a precise calculation. This study investigated the precision of various methods of ITS estimations and their application to two clinical situations: plasma exchange and immune suppression targeting ITS . Methods Based on a mathematical model of ITS , we constructed a population of healthy controls and applied a tunable ITS . Results We demonstrate the following results: underestimation of ITS is common at individual level but true ITS is well fitted by cohorts; Q IgG increases after plasma exchange; Ig G Loc calculation based on Qlim falsely increases when Q Alb decreases; the sample size required to demonstrate a decrease in ITS increases exponentially with larger Q Alb . Interpretation Studies evaluating changes in ITS level should be adjusted to Q Alb . Low amounts of ITS could be largely underestimated.