Evaluation of CSF-Chlamydia pneumoniae, CSF-tau, and CSF-Abeta42 in Alzheimer's disease and vascular dementia.

The potential role of microbiological factors such as Chlamydia pneumoniae (ChP) in the pathogenesis of neurodegenerative disorders, including Alzheimer's disease (AD) and vascular dementia (VD), has been suggested, but the correctness of this hypothesis still needs to be tested. In this study the appearance of ChP in the cerebrospinal fluid (CSF) of 57 AD and 21 VD patients and in 47 controls (CG) as well as the influence of ChP on the levels of tau protein and Abeta42 were investigated. The frequency of ChP occurrence in the AD patient group (43.9%) was significantly higher (p < 0.001) than in the control group (10.6%). In the case of VD patients, 9.5% of this group was positive for ChP. The presence of ChP DNA in the CSF of patients with AD significantly increases the occurrence of this disease (odds ratio = 7.21). Cerebrospinal fluid Abeta42 levels were significantly lower in patients with AD than in the CG (p < 0.001). Cerebrospinal tau protein was significantly higher in AD vs. CG (p = 0.007). However, no relationships between the presence of the bacterium in CSF and the level of either tau or Abeta42 protein were observed. In conclusion, we may suspect that testing for the presence of ChP in CSF, along with the tau and Abeta42 markers, may be used in the clinic diagnosis of AD.