Interleukin-12 is reduced in cerebrospinal fluid of patients with Alzheimer's disease and frontotemporal dementia.
Interleukin-12 is a heterodimeric cytokine produced by activated blood monocytes, macrophages and glial cells. It enhances differentiation and proliferation of T cells and increases production of proinflammatory cytokines, such as Interferon-gamma and Tumor Necrosis Factor-alpha. There is little information about the involvement of IL-12 in the pathophysiology of Alzheimer's disease (AD) and other tauopathies.


OBJECTIVE
The objective of our study was to assess the role of IL-12 as a potential marker of immune reactions in patients with AD and frontotemporal dementia (FTD).


METHODS
We measured by immunoassay cerebrospinal fluid (CSF) IL-12 levels in 19 patients with AD and 7 patients with FTD in comparison with CSF IL-12 levels in 30 patients with non-inflammatory neurological diseases served as neurological control patients (NCTRL). IL-12 levels were correlated with age, age of disease onset, disease duration, MMSE score, and rate of dementia progression. Abeta42 and Total tau (tau(T)) levels in CSF were also measured.


RESULTS
Patients with AD had significantly lower CSF IL-12 levels compared with NCTRL patients (p<0.001). Patients with FTD had also lower CSF IL-12 levels compared with NCTRL patients (p<0.05). Age, sex, disease duration and MMSE score did not affect IL-12 levels in any of the groups. In AD a significant positive correlation was noted between IL-12 levels and tau(T) levels (Rs=0.46, p=0.048).


CONCLUSIONS
Our findings may suggest a reduced inflammatory reaction during the course of AD and FTD. A neurotrophic role of IL-12 and other proinflammatory cytokines cannot be excluded.
Rentzos
Michael
M
Department of Neurology, Aeginition Hospital, Athens National University, School of Medicine, 72-74 Vas. Sophias Ave, Athens 11528, Greece. mrentzos@med.uoa.gr
Paraskevas
George P
GP
Kapaki
Elisabeth
E
Nikolaou
Chryssoula
C
Zoga
Margarita
M
Rombos
Antonis
A
Tsoutsou
Anthousa
A
Vassilopoulos D
Demetris
D
D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000544:Alzheimer Disease / Q000134:cerebrospinal fluid* / Q000503:physiopathology; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid; D003704:Dementia / Q000134:cerebrospinal fluid*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007249:Inflammation; D018664:Interleukin-12 / Q000134:cerebrospinal fluid*; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000134:cerebrospinal fluid; D009483:Neuropsychological Tests; D012720:Severity of Illness Index; D016875:tau Proteins / Q000134:cerebrospinal fluid
D016229:Amyloid beta-Peptides; C054369:MAPT protein, human; D016875:tau Proteins; D018664:Interleukin-12