How does this square with a primary Chl pneumoniae infection?
Human Herpes Virus 6 may have a secondary input into MS; read a brief note about this on page 5. Can a chlamydial cause for MS be proved in an individual patient by serology? Not at the moment. This because Chl pneumoniae is a common organism and infections with the bacterium are common. Antibody levels tend to rise during life, even in people who are asymptomatic. Patients with extracerebral infections of some duration (particularly reactive arthritis) can show high titres in the microimmunofluorescence test; it is generally reckoned that a titre of 1:512 or above, in the presence of appropriate clinical findings, supports a diagnosis of Chl pneumoniae disease. MS is different; the pathology is at the blood-brain barrier. One would not expect an elevation of circulating antibodies unless an extracerebral component to the infection were also present. This may be the case in progressive disease; there is a statistical elevation of antibodies in a group of such patients. This supports th
