Le dosage du peptide Aβ, des protéines Tau et tau phosphorylée dans le liquide céphalorachidien (LCR) des patients suspects de maladie d’Alzheimer impose des contraintes préanalytiques. Nous avons analysé les modalités de prélèvement et de transport du LCR dans les centres mémoire de ressources et de recherche (CMRR).

Un auto-questionnaire sur la pratique de la ponction lombaire (PL) et une étude prospective sur la faisabilité et les effets secondaires de la PL ont été envoyés aux CMRR français.

Dix-huit des 26 CMRR (69 %) ont répondu à l’auto-questionnaire. L’analyse des résultats mettait en évidence une variabilité intercentre, notamment sur le volume prélevé, le tube utilisé et le repos post-PL. L’enquête prospective réalisée avec 16 des 26 CMRR (62 %) répondeurs révélait une excellente acceptation (93 %) et faisabilité (97 %° de la PL).

Tous les centres français respectent les recommandations de prélèvement, transport et conservations du LCR. Toutefois, chaque centre a mis en place sa propre procédure. Ces résultats ne nous permettent pas de conclure quant à l’influence des différentes procédures sur la variabilité des dosages des biomarqueurs. Des pratiques plus homogènes entre centres permettraient une optimisation de l’interprétation et de la comparaison intercentres des biomarqueurs. L’enquête prospective confirme la très bonne acceptation et faisabilité de la PL dans le cadre des troubles cognitifs.

Cerebrospinal fluid (CSF) biomarkers have been extensively studied as diagnostic markers for Alzheimer’s disease (AD). However, results are variable probably due to lumbar puncture (LP) procedure, CSF collection and transport. This intercenter variability highlights the need for an efficient standardization of clinical and technical procedures. The aims of this study were firstly to compare the LP procedure and CSF transport process in all French Memory Centers and secondly to evaluate the incidence of LP side effects in 100 patients with cognitive disturbances.

LP practice and side effect prospective questionnaires were sent to all French Memory Centers in May 2010. Memory Centers were asked about their LP procedure. The prospective study over a three-week-period has evaluated the LP feasibility and side effects. All data were collected until the end of July 2010.

The answers of 18 out of 26 Memory Centers were collected. Although, these centers did not have the same LP procedure and CSF transport, the majority of them proceeded according to Innogenetics’s advices concerning the use of polypropylene tubes and transport duration but not sample conditioning. Polypropylene tubes were different from one center to the other. CSF volume, pharmacological premedication and prevention of post-LP syndrome were variable in all responding centers. The prospective study carried out in 100 patients revealed a very good LP acceptability (93/100 patients). LP feasibility was 97 % (90/93) and failed LP were consequently performed with success using radiological scopes. Three minor complications were observed.

All French Centers complied with Innogenetics’ recommendations for pretechnical CSF procedures; however each Center put in place its own procedure that was different one center to the other. It will be very interesting to compare cut-off and result values for Aβ, tau and phosphorylated tau protein on threonine 181 between several centers that used their own procedures. Acceptability and safety were very good in our short but significant prospective study. These results confirm the data of Zetterberg et al., 2010Zetterberg H., Tullhög K., Hansson O., Minthon L., Londos E., Blennow K. Low incidence of post-lumbar puncture headache in 1089 consecutive memory clinic patients Eur Neurol 2010 ;  63 : 326-330 [cross-ref]

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