Intra vitam lumbar and post mortem ventricular cerebrospinal fluid immunoreactive interleukin-6 in Alzheimer's disease patients

OBJECTIVES: In view of contradictory findings in previous studies, to examine the diagnostic value of interleukin-6 measurements in cerebrospinal fluid (CSF) of Alzheimer's disease patients. MATERIAL AND METHODS: Interleukin-6-immunoreactivity (IL-6-IR) was measured in 169 intra vitam lumbar and 21 post mortem ventricular CSF samples of patients with probable and neuropathologically confirmed Alzheimer's disease (AD), non-AD dementias (NAD), neurological disorders without cognitive impairment (OND) and controls (CON) using a specific sandwich enzyme immunoassay. RESULTS: Intra vitam lumbar samples had significantly elevated (P < 0.03) IL-6-IR not only in the AD, but also in the NAD and OND group compared with controls. AD patients with late onset (> 65 years) had slightly (P > 0.05) higher values than patients with early onset (< 65 years). In post mortem ventricular fluid, differences among groups did not reach significance (P > 0.05). CONCLUSION: We conclude that elevations of CSF IL-6-IR can not serve as a diagnostic marker of the disease, but, hypothetically, could reflect presence or activity of IL-6 mediated immunological phenomena in single AD patients.