C-reactive protein level is decreased in patients with Alzheimer's disease and related to cognitive function and survival time.

Previous studies have observed decreased serum CRP levels in patients with established Alzheimer's disease (AD) compared to controls or other diagnostic groups of elderly patients with mental illness.We have investigated the relation between CRP level and the severity of AD as assessed by cognitive function, brain imaging and survival time.Patients with AD showed overall lower CRP levels than other patients with mental illness, but elevated CRP levels in these patients were associated with lower cognitive function and shorter survival time.The reason for an overall low CRP level is not obvious. Elevated CRP level in patients with AD suggests the presence of inflammatory activity in this subgroup of patients that may benefit from anti-inflammatory administration.