Below is a brief summary of dates of CSF biomarker analyses run as batches of samples using the Luminex xMAP platform and Innogenetics INNO-BIA AlzBio3? immunoassay reagents. Normalization of CSF biomarker data between results of 2007 and 2008 have been obtained using a statistical approach, resulting in a procedure to maintain lot-to-lot consistency within clinical studies. In addition, during the further review of the pTau181p data a subset of CSF samples required quaranteening all pTau181p data from the late 2008 batch run. The normalization applies to all t-tau, A?1-42 and pTau181p results, with the exception of the subset of pTau181p results that require a special correction procedure that is in the process of being completed. That specific subset of data will be uploaded in the near future.

Batch runs of ADNI CSF samples
COLLECTIONS

1. BASELINE CSFs were collected through early September 2007
2. YR1 CSFs collected through late September 2008
3. 24 month and 36 month sample collections-still ongoing

BIOMARKER BATCH TESTING

1. BASELINE CSFs (“adni_upennbiomk_*.csv”), batch tested Nov-Dec 2007, uploaded on ADNI website: A?1-42, t-tau, pTau181p data early 2008, THIS IS A FINAL DATASET (REPORTED in Annals of Neurology, 2009). Data were reported on 410 subjects as described in the Annals of Neurology publication (Cerebrospinal fluid biomarker signature in Alzheimer’s Disease Neuroimaging Initiative subjects. Shaw LM, Vanderstichele H, Knapik-Czajka M, Clark C, Aisen PS, Petersen RC, Blennow K, Soares H, Simon A, Lewczuk P, Dean R, Siemers E, Potter W, Lee VM-Y, Annals of Neurology 2009; available on the publisher’s website).
2. BASELINE, YR1 and 24 month samples batch tested Nov-Dec 2008 (Included 59 24 month CSFs; “adni_upennbiomk2_*.csv”), uploaded preliminary dataset Feb 2009, without pTau181p, and need for “bridge” to 2007 data. We will soon follow up with a replacement upload of the A?1-42, and t-tau data following statistical normalization “bridging” data collected using different lot numbers of Innogenetics research reagents.
3. Retested all 91 sets of “triplet” CSF samples (BASELINE, YR1 and 24 month CSFs; each sample done using standard protocol and a new protocol to help deal with ptau), Feb-March 2009, analyses of these data are ongoing.
4. In addition, studies were done to bridge between single analyte testing and multi-analyte testing using a modified test procedure requiring lower volumes of CSF. 91 sets of “triplet” CSF samples (BASELINE, YR1 and YR2) were tested using the standard protocol and a new test procedure to improve test accuracy for CSF p-Tau181p, Feb-March 2009. Data analyses of this is on-going.

– Mike Donohue