Correlation of chlamydia pneumoniae infection and severity of accelerated graft arteriosclerosis after cardiac transplantation.
BACKGROUND
Chlamydia pneumoniae has been associated with atherosclerosis, although its role in the process is not clearly defined. Heart transplant recipients are known to have high titers of antibodies to C. pneumoniae, and the organism has been recovered from the coronary arteries of both transplant recipients and donors. This study evaluated association between C. pneumoniae infection and accelerated graft arteriosclerosis (AGA), also known as cardiac allograft vasculopathy (CAV), after cardiac transplantation.


METHODS
A case-control study was performed with 54 heart transplant recipients at the Johns Hopkins Hospital. Severe cases had >50% luminal narrowing on cardiac catheterization, mild cases <50% narrowing, and controls were free of arteriosclerotic disease. Blood specimens were examined for C. pneumoniae serology and DNA detection by polymerase chain reaction (PCR) assays.


RESULTS
For every twofold increase in geometric mean C. pneumoniae immunoglobulin (Ig)G titer, the odds ratio for severe AGA versus controls was 3.13 (P=0.03) and for mild AGA versus control patients was 1.61 (P=0.45). On Kaplan-Meier survival analysis there was a nonsignificant trend toward faster development of CAV in patients with higher C. pneumoniae antibody titers. Overall, 29% of heart transplant patients evaluated had evidence of circulating C. pneumoniae DNA by PCR, without a statistical difference between groups.


CONCLUSIONS
C. pneumoniae IgG titer correlates with severity of allograft arteriosclerosis after cardiac transplantation. Circulating C. pneumoniae DNA is detectable by PCR in up to 30% of cardiac transplant recipients, but this does not correlate with severity of allograft vasculopathy.
Subramanian
Aruna K
AK
Division of Infectious Diseases, Department of Medicine, Johns Hopkins University, Baltimore, Maryland 21287, USA. asubra@jhmi.edu
Quinn
Thomas C
TC
Kickler
Thomas S
TS
Kasper
Edward K
EK
Tucker
Pamela C
PC
D000328:Adult; D000368:Aged; D000907:Antibodies, Bacterial / Q000097:blood; D001161:Arteriosclerosis / Q000209:etiology*; D016022:Case-Control Studies; D002690:Chlamydia Infections / Q000150:complications*; D016993:Chlamydophila pneumoniae; D003586:Cytomegalovirus Infections / Q000150:complications; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D014184:Transplantation, Homologous
D000907:Antibodies, Bacterial; D004269:DNA, Bacterial; D007074:Immunoglobulin G