TY - JOUR
T1 - Cerebrospinal fluid biomarker and brain biopsy findings in idiopathic normal pressure hydrocephalus
AU - Pyykkö, Okko T.
AU - Lumela, Miikka
AU - Rummukainen, Jaana
AU - Nerg, Ossi
AU - Seppälä, Toni T.
AU - Herukka, Sanna-Kaisa
AU - Koivisto, Anne M.
AU - Alafuzoff, Irina
AU - Puli, Lakshman
AU - Savolainen, Sakari
AU - Soininen, Hilkka
AU - Jääskeläinen, Juha E.
AU - Hiltunen, Mikko
AU - Zetterberg, Henrik
AU - Leinonen, Ville
PY - 2014/3/17
Y1 - 2014/3/17
N2 - Background: The significance of amyloid precursor protein (APP) and neuroinflammation in idiopathic normal pressure hydrocephalus (iNPH) and Alzheimer's disease (AD) is unknown. Objective: To investigate the role of soluble APP (sAPP) and amyloid beta (Ab) isoforms, proinflammatory cytokines, and biomarkers of neuronal damage in the cerebrospinal fluid (CSF) in relation to brain biopsy Ab and hyperphosphorylated tau (HPt) findings. Methods: The study population comprised 102 patients with possible NPH with cortical brain biopsies, ventricular and lumbar CSF samples, and DNA available. The final clinical diagnoses were: 53 iNPH (91% shunt-responders), 26 AD (10 mixed iNPH+AD), and 23 others. Biopsy samples were immunostained against Aβ and HPτ. CSF levels of AD-related biomarkers (Aβ42, p-tau, total tau), non-AD-related Aβ isoforms (Aβ38, Aβ40), sAPP isoforms (sAPPa, sAPPb), proinflammatory cytokines (several interleukins (IL), interferon-gamma, monocyte chemoattractant protein-1, tumor necrosis factor-alpha) and biomarkers of neuronal damage (neurofilament light and myelin basic protein) were measured. All patients were genotyped for APOE. Results: Lumbar CSF levels of sAPPα were lower (p<0.05) in patients with shunt-responsive iNPH compared to non-iNPH patients. sAPPβ showed a similar trend (p= 0.06). CSF sAPP isoform levels showed no association to Aβ or HPτ in the brain biopsy. Quantified Aβ load in the brain biopsy showed a negative correlation with CSF levels of Aβ42 in ventricular (r=20.295, p=0.003) and lumbar (r=20.356, p=0.01) samples, while the levels of Aβ38 and Aβ40 showed no correlation. CSF levels of proinflammatory cytokines and biomarkers of neuronal damage did not associate to the brain biopsy findings, diagnosis, or shunt response. Higher lumbar/ventricular CSF IL-8 ratios (p<0.001) were seen in lumbar samples collected after ventriculostomy compared to the samples collected before the procedure. Conclusions: The role of sAPP isoforms in iNPH seems to be independent from the amyloid cascade. No neuroinflammatory background was observed in iNPH or AD. Copyright:
AB - Background: The significance of amyloid precursor protein (APP) and neuroinflammation in idiopathic normal pressure hydrocephalus (iNPH) and Alzheimer's disease (AD) is unknown. Objective: To investigate the role of soluble APP (sAPP) and amyloid beta (Ab) isoforms, proinflammatory cytokines, and biomarkers of neuronal damage in the cerebrospinal fluid (CSF) in relation to brain biopsy Ab and hyperphosphorylated tau (HPt) findings. Methods: The study population comprised 102 patients with possible NPH with cortical brain biopsies, ventricular and lumbar CSF samples, and DNA available. The final clinical diagnoses were: 53 iNPH (91% shunt-responders), 26 AD (10 mixed iNPH+AD), and 23 others. Biopsy samples were immunostained against Aβ and HPτ. CSF levels of AD-related biomarkers (Aβ42, p-tau, total tau), non-AD-related Aβ isoforms (Aβ38, Aβ40), sAPP isoforms (sAPPa, sAPPb), proinflammatory cytokines (several interleukins (IL), interferon-gamma, monocyte chemoattractant protein-1, tumor necrosis factor-alpha) and biomarkers of neuronal damage (neurofilament light and myelin basic protein) were measured. All patients were genotyped for APOE. Results: Lumbar CSF levels of sAPPα were lower (p<0.05) in patients with shunt-responsive iNPH compared to non-iNPH patients. sAPPβ showed a similar trend (p= 0.06). CSF sAPP isoform levels showed no association to Aβ or HPτ in the brain biopsy. Quantified Aβ load in the brain biopsy showed a negative correlation with CSF levels of Aβ42 in ventricular (r=20.295, p=0.003) and lumbar (r=20.356, p=0.01) samples, while the levels of Aβ38 and Aβ40 showed no correlation. CSF levels of proinflammatory cytokines and biomarkers of neuronal damage did not associate to the brain biopsy findings, diagnosis, or shunt response. Higher lumbar/ventricular CSF IL-8 ratios (p<0.001) were seen in lumbar samples collected after ventriculostomy compared to the samples collected before the procedure. Conclusions: The role of sAPP isoforms in iNPH seems to be independent from the amyloid cascade. No neuroinflammatory background was observed in iNPH or AD. Copyright:
U2 - 10.1371/journal.pone.0091974
DO - 10.1371/journal.pone.0091974
M3 - Article
C2 - 24638077
AN - SCOPUS:84898657736
SN - 1932-6203
VL - 9
JO - PLOS ONE
JF - PLOS ONE
IS - 3
M1 - e91974
ER -