Detection of Chlamydia Pneumoniae in Blood Samples: A Diagnostic Screen for Alzheimer Disease

Date of Award


Degree Type


Degree Name

Master of Science (MS)

First Advisor

Brian J Balin, PhD

Second Advisor

Denah M Appelt, PhD

Third Advisor

Katherine Galluzzi, DO, CMD, F ACOFP

Fourth Advisor

C Scott Little, PhD


We examined blood samples from 16 individuals over the age of 65 who were either residents of a nursing home or patients in a geriatric medicine clinic. Each patient underwent psychometric testing in order to be placed in the appropriate category for their particular cognitive status; AD, MCI, or cognitively normal. After psychometric testing, blood was drawn from the patients and these samples were assessed for the presence of Chlamydia pneumoniae (Cpn), an obligate intracellular pathogen, in an attempt to correlate cognitive status with presence of infection. Multiple methodologies were utilized in determining presence of infection. While our Real Time-PCR results remain below the level of detection due to presumed inhibition, complete blood count with differential and Chlamydia pneumoniae serological data demonstrated 14/16 patients tested positive for at least one of the three immunoglobulin classes included in the report; IgM, IgA, or IgG. Analysis by immunocytochemistry revealed 12/16 patient samples were considered positive for Chlamydia when labeled with a genus-specific antiChlamydia! antibody. For additional confirmatory studies to identify Cpn infection, patient samples were prepared for electron microscopy. These results demonstrated presence of likely elementary bodies, intravacuolar reticulate bodies, and also intermediate bodies, in which all are characteristic of Chlamydia pneumoniae infection. Thus, Chlamydia pneumoniae is present in the majority of blood samples of patients who pmiicipated in this study. While we are blinded to the psychometric testing results until the conclusion of the ongoing study, suggestions can be made that those patients exhibiting positive Chlamydia pneumoniae infection by multiple methods also may be displaying more severe signs of cognitive impairment.

This document is currently not available here.