Chlamydophila pneumoniaeInfection and Its Role in Neurological Disorders

Abstract

Chlamydophila pneumoniae is an intracellular pathogen responsible for a number of different acute and chronic infections. The recent deepening of knowledge on the biology and the use of increasingly more sensitive and specific molecular techniques has allowed demonstration of C. pneumoniae in a large number of persons suffering from different diseases including cardiovascular (atherosclerosis and stroke) and central nervous system (CNS) disorders. Despite this, many important issues remain unanswered with regard to the role that C. pneumoniae may play in initiating atheroma or in the progression of the disease. A growing body of evidence concerns the involvement of this pathogen in chronic neurological disorders and particularly in Alzheimer's disease (AD) and Multiple Sclerosis (MS). Monocytes may traffic C. pneumoniae across the blood-brain-barrier, shed the organism in the CNS and induce neuroinflammation. The demonstration of C. pneumoniae by histopathological, molecular and culture techniques in the late-onset AD dementia has suggested a relationship between CNS infection with C. pneumoniae and the AD neuropathogenesis. In particular subsets of MS patients, C. pneumoniae could induce a chronic persistent brain infection acting as a cofactor in the development of the disease. The role of Chlamydia in the pathogenesis of mental or neurobehavioral disorders including schizophrenia and autism is uncertain and fragmentary and will require further confirmation.

Role of Chlamydia in the Development of Ocular Adnexal Lymphoma

“…Thus, the immune response to microbial Hsp-60 may gradually lead or contribute to autoimmunity to host self antigens and conesquently, to the development of chronic diseases such as asthma, stroke, degenerative joint diseases, atherosclerosis, coronary heart disease, multiple sclerosis [56][57][58][59][60][61] or favor the onset of cancer [62] or lymphoma. Chronic infections by C. pneumoniae are associated with small and squamous lung cancer and cutaneous T-cell lymphoma [63].…”

“…In fact, as happens in various chronic diseases, C. pneumoniae may be transported by infected monocytes and participate in the maintenance of local immunological response and inflammation, delaying its clearance [61,68].…”

Chlamydia: Possible Mechanisms of the Long Term Complications

“…Genetic predisposition with a combination of infectious agents has been implicated in MS pathogenesis. The presence of C. pneumoniae is still under debate and shows a great variability from 0 to 43% in different studies using PCR techniques (Contini et al, 2010). Several authors indicate that the presence of microorganism may partially influence the occurrence of MS, being linked to the progressive form of the disease (Munger et al, 2003).…”

“…These patients are young, have neurological symptoms or radiographic evidence and also have acute symptoms of respiratory infection, and laboratory evidence indicating C. pneumoniae. Acute demyelinating encephalitis, cerebellar axatia and Gullian Barre are some of the clinical forms in which faster recovery after antibiotic therapy demonstrates the relation between microorganism and neurological presentations (Contini et al, 2010).…”

The human genome is composed of viral DNA: Viral homologues of the protein products cause Alzheimer's disease and others via autoimmune mechanisms.

“…These features, including betaamyloid deposition, tau phosphorylation 35 59,75 , entorhinal and hippocampal cell loss and cerebral shrinkage 4 can all be induced by Herpes simplex viral infection in mice. Several hundred genes have been implicated in the disease 8 (see http://www.polygenicpathways.co.uk/alzpolys.html , and a number of environmental risk factors including viral infection (Herpes viruses HSV-1 36,37 and the cytomegalovirus) , and bacterial and parasitic infection (C.Pneumoniae 17,49 , Borrelia Burgdorferri 53 and Helicobacter pylori) have also been shown to promote risk 31 . Indeed eradication of H.Pylori has been reported to improve cognitive performance 44 .…”