Chlamydia pneumoniae and atherosclerosis

Abstract

Objective-To review the literature for evidence that chronic infection with Chlamydia pneumoniae is associated with atherosclerosis and acute coronary syndromes. Data sources-MEDLINE and Institute of Science and Information bibliographic databases were searched at the end of September 1998. Indexing terms used were chlamydi*, heart, coronary, and atherosclerosis. Serological and pathological studies published as papers in any language since 1988 or abstracts since 1997 were selected. Data extraction-It was assumed that chronic C pneumoniae infection is characterised by the presence of both specific IgG and IgA, and serological studies were examined for associations that fulfilled these criteria. Pathological studies were also reviewed for evidence that the presence of C pneumoniae in diseased vessels is associated with the severity and extent of atherosclerosis. Data synthesis-The majority of serological studies have shown an association between C pneumoniae and atherosclerosis. However, the number of cases in studies that have reported a positive association when using strict criteria for chronic infection is similar to the number of cases in studies which found no association. Nevertheless, the organism is widely found in atherosclerotic vessels, although it may not be at all diseased sites and is not confined to the most severe lesions. Rabbit models and preliminary antibiotic trials suggest that the organism might exacerbate atherosclerosis. Conclusion-More evidence is required before C pneumoniae can be accepted as playing a role in atherosclerosis. Although use of antibiotics in routine practice is not justified, large scale trials in progress will help to elucidate the role of C pneumoniae. (Heart 1999;81:232-238) The organism now known as Chlamydia pneumoniae was first isolated in 1965 in Taiwan. It was subsequently recognised to be a cause of acute respiratory disease 1 giving rise to the acronym TWAR (Taiwan acute respiratory) agent. Chlamydia are unique, obligate, intracellular bacterial pathogens of eukaryotic cells. As they are diYcult organisms to culture, much knowledge about C pneumoniae infections has come from serological studies, many of which, since 1988, have shown an association between C pneumoniae infection and atherosclerosis. However, association does not prove causality and, unfortunately, serological distinction between past and current infection is diYcult.In a general population, infection was absent in children under 5 years, attaining a peak incidence of 9.2% in those aged 5-10 years before falling to 1.5% over the age of 20.2 By the age of 20 years, prevalence of specific IgG has already reached 50%, persisting or even increasing with age.3-5 Seroprevalence is proportional to the product of annual incidence and the duration of seropositivity following infection. As specific IgG antibodies are thought to disappear about three years following primary C pneumoniae infection, 6 an annual incidence of 1.5% should result in a prevalence of 4.5% rather than the observed 50%. ...

The Impact of Infection on Chronic Allograft Dysfunction and Allograft Survival After Solid Organ Transplantation

“…In the literature, chronic chlamydial infection has been described as a possible factor involved in the pathogenesis of cardiovascular diseases (182,183). Efforts to determine the pathogenic role of Chlamydia pneumoniae in atherosclerotic cardiovascular disease have included animal model studies, mechanistic studies and clinical trials of antibiotic treatment (184,185).…”

Chlamydia pneumoniae y aterosclerosis: Mecanismos patogénicos

“…En diversas investigaciones epidemiológicas, se ha encontrado una asociación entre Chlamydia pneumoniae y aterosclerosis ( [15][16][17][18][19] ). Los Centros para el Control y Prevención de Enfermedades (CDC) han incluido esta asociación en el contexto de enfermedades emergentes del nuevo siglo ( 20 ), lo que traduce la importancia que representan los hallazgos que se tiene hasta la fecha con relación a aterosclerosis y C. pneumoniae.…”

“…Se ha propuesto una teoría infecciosa para explicar la ocurrencia de isquemia cerebral aguda ( 19,(91)(92)(93)(94) ), así como la existente para las enfermedades cardiovasculares. No pocos investigadores han encontrado una asociación entre C. pneumoniae y enfermedades cerebrovasculares.…”

Detección de Chlamydia pneumoniae en tejido aórtico humano: amplificación del gen kdtA e hibridación in vitro.

“…pneumoniae es una bacteria intracelular obligada que no puede generar ATP independientemente y, por lo tanto, debe hacer uso del que produce la célula hospedera (7,8). Se encuentra ampliamente distribuida a nivel mundial y es un agente causal común de enfermedad respiratoria aguda (7,8).…”

“…pneumoniae es una bacteria intracelular obligada que no puede generar ATP independientemente y, por lo tanto, debe hacer uso del que produce la célula hospedera (7,8). Se encuentra ampliamente distribuida a nivel mundial y es un agente causal común de enfermedad respiratoria aguda (7,8). Además, tiene la capacidad de infectar y multiplicarse en distintos tipos de células que comúnmente se encuentran en ateromas, incluidas las células endoteliales, los macrófagos y las células de músculo liso vascular (2,16,17).…”