Antibody response to chlamydial heat shock protein 60 is strongly associated with acute coronary syndromes.
BACKGROUND
Heat shock proteins (HSPs) are a family of proteins with immunogenic and proinflammatory properties. Human and Chlamydia pneumoniae (Cp) HSP60 were found in patients with stable coronary disease.


RESULTS
We measured the levels of anti-Cp-HSP60 and anti-Cp immunoglobulin G (IgG) in 179 patients with unstable angina, 40 with acute myocardial infarction, and 40 with stable angina (SA), as well as 100 control subjects. Forty-one patients with acute coronary syndromes (ACS) were also studied at follow-up. We also measured plasma levels of high-sensitivity C-reactive protein (hs-CRP) and troponin T (TnT). Seropositivity to Cp-HSP60 was found in 99% of ACS patients but in only 20% of SA patients and none of the control subjects. Seropositivity to Cp was detected in 67% of ACS patients, 60% of SA patients, and 30% of the control subjects. No differences in Cp-HSP60 IgG and in Cp IgG were observed between patients with myocardial infarction and patients with unstable angina. No correlation was found between Cp-HSP60 IgG, TnT, and hs-CRP or between IgG against Cp and hs-CRP. In ACS patients at follow-up, Cp-HSP60 IgG decreased from 0.88+/-0.25 to 0.45+/-0.14 arbitrary units (P<0.0001), becoming negative in 12 patients.


CONCLUSIONS
Seropositivity for Cp-HSP60 appears to be a very sensitive and specific marker of ACS, unrelated to Cp IgG antibody titers or hs-CRP and TnT levels. Its causal involvement in instability and its diagnostic role in ACS deserve further study.
Biasucci
Luigi M
LM
Institute of Cardiology, Universita' Cattolica, Roma, Italy. lmbiasucci@virgilio.it
Liuzzo
Giovanna
G
Ciervo
Alessandra
A
Petrucca
Andrea
A
Piro
Maddalena
M
Angiolillo
Dominick J
DJ
Crea
Filippo
F
Cassone
Antonio
A
Maseri
Attilio
A
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000097:blood / Q000276:immunology; D000907:Antibodies, Bacterial / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D018834:Chaperonin 60 / Q000276:immunology*; D016993:Chlamydophila pneumoniae / Q000276:immunology*; D003327:Coronary Disease / Q000097:blood / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000276:immunology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D012698:Serologic Tests; D020107:Troponin T / Q000097:blood
D000907:Antibodies, Bacterial; D018834:Chaperonin 60; D007074:Immunoglobulin G; D020107:Troponin T; D002097:C-Reactive Protein