Serum Nogo-A levels are not elevated in amyotrophic lateral sclerosis patients.
Improved biomarkers would facilitate the diagnosis and treatment of amyotrophic lateral sclerosis (ALS). Muscle content of the neuritic outgrowth inhibitor Nogo-A is increased in patients with ALS and other denervating conditions. Seeking a less invasive diagnostic method, we sought to determine whether or not Nogo increases in the serum of ALS patients. We developed a dissociation-enhanced lanthanide fluorescent immunoassay (DELFIA) protocol to screen serum samples from 172 ALS patients and 172 healthy controls for Nogo-A immunoreactivity. Unexpectedly, there was a trend toward decreased levels of serum Nogo-A in ALS. Mean serum Nogo-A level in ALS patients was 0.71 nM (95% confidence interval (CI) 0.42-1.00), as opposed to 1.15 nM (95% CI 0.72-1.59) in healthy controls. A significantly larger percentage of healthy control sera (11.0% vs 4.7%) displayed markedly elevated levels of Nogo-A. Additional study is required to determine the factors that lead to elevated Nogo-A levels in a subset of both ALS patients and healthy controls.
Harel
Noam Y
NY
Department of Neurology, Yale University School of Medicine, New Haven, CT 06520-8018, USA. noam.harel@yale.edu
Cudkowicz
Merit E
ME
Brown
Robert H
RH
Strittmatter
Stephen M
SM
D000690:Amyotrophic Lateral Sclerosis / Q000175:diagnosis*; D015415:Biomarkers / Q000032:analysis / Q000097:blood*; D016022:Case-Control Studies; D006801:Humans; D007118:Immunoassay / Q000379:methods; D028581:Lanthanoid Series Elements; D018482:Muscle, Skeletal / Q000737:chemistry
D015415:Biomarkers; D028581:Lanthanoid Series Elements