J Psychiatry Neurosci 2010;35(1):59-62
Paul L. Wood, PhD; Rishikesh Mankidy, PhD; Shawn Ritchie, PhD; Doug Heath, MSc; Julie A. Wood, MD; John Flax, MD; Dayan B. Goodenowe, PhD
P. Wood — Phreedom Pharma; Mankidy, Ritchie, Heath, J. Wood, Goodenowe — Phenomenome Discoveries, Saskatoon,Sask.; Flax — PrecisionMed Inc., San Diego, Calif.
Background: Plasmalogens, which are key structural phospholipids in brain membranes, are decreased in the brain and serum of patients with Alzheimer disease (AD). We performed this pilot study to evaluate the relation between the levels of circulating plasmalogens and Alzheimer Disease Assessment Scale–Cognitive (ADAS-Cog) scores in patients with AD.
Methods: We evaluated participants’ ADAS-Cog scores and serum plasmalogen levels. For the 40 included AD patients with an ADAS-Cog score between 20 and 46, were tested their ADAS-Cog score 1 year later. The levels of docosahexaenoic acid plasmalogen were measured by use of liquid chromatography–tandem mass spectrometry.
Results: We found that the ADAS-Cog score increased significantly in AD patients with circulating plasmalogen levels that were > 75% of that of age-matched controls at entry into the study. There was no change in score among participants with normal serum plasmalogen levels at baseline (>75%).
Limitations: This was a pilot study with 40 patients, and the results require validation in a larger population.
Conclusion: Our study demonstrates that decreased levels of plasmalogen precursors in the central nervous system correlate with functional decline (as measured by ADAS-Cog scores) in AD patients. The use of both ADAS-Cog and serum plasmalogen data may be a more accurate way of predicting cognitive decline in AD patients, and may be used to decrease the risk of including patients with no cognitive decline in the placebo arm of a drug trial.
Competing interests: Dr. P. Wood is CEO of and owns stock in Phreedom Pharma. Drs. Mankidy, Ritchie, Heath and J. Wood are employed by Phenomenome Discoveries. Dr. Goodenowe is CEO of and owns stock in Phenomenome Discoveries. Dr. Flax is employed by and owns stock in PrecisionMed, Inc. None declared for Dr. Mankidy.
Contributors: Drs. P. Wood and Goodenowe designed the study and wrote the article. Drs. P. Wood, Mankidy, Ritchie, Heath and Flax acquired the data, which Drs. P. Wood, Ritchie, Heath, J. Wood and Goodenowe analyzed. Drs. Mankidy, Richie, Heath, J. Wood and Flax reviewed the article. All authors approved its publication.
Submitted May 19, 2009; Revised Aug. 31, 2009; Accepted Sept. 7, 2009.
Correspondence to: Dr. P.L. Wood, Phreedom Pharma, 204-407 Downey Rd., Saskatoon SK S7N 4L8; fax 306 244-6730; firstname.lastname@example.org