Article

Circulating cardiac troponin-I autoantibodies in human plasma and serum.

Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, Illinois 60064-6016, USA.
Annals of the New York Academy of Sciences (impact factor: 3.15). 09/2009; 1173:67-74. DOI:10.1111/j.1749-6632.2009.04617.x pp.67-74
Source: PubMed

ABSTRACT We identified IgG reactive with human cardiac troponin-I (cTnI) in plasma and serum samples (N = 1930) from normal blood donors, and in sample cohorts characterized on the basis of clinical biomarkers associated with cardiac, infectious, and autoimmune diseases. cTnI and brain natriuretic peptide were the biomarkers chosen to reflect myocyte damage or left ventricular dysfunction, respectively. The infectious disease cohorts were serologically positive for antibodies to hepatitis B (natural infection), hepatitis C virus, and Chagas (i.e., T.cruzi). The autoimmune cohorts were represented by samples from diagnosed systemic lupus erythematosus (biomarker: dsDNA) and rheumatoid arthritis (biomarker: rheumatoid factor) subjects. The prevalence of IgG autoantibodies reactive with cTnI was high in the normal donor cohort (95/750, 12.7%). The prevalence in the other sample cohorts was not significantly different from that in the normal blood donors, with the exception of a slight increase in the rheumatoid factor cohort (28/137, 20.4%). The presence of anti-cTnI IgG in highly reactive samples was confirmed by inhibition with the antigen and further by screening with a library of peptides derived from the human cTnI amino acid sequence. Our data suggest that these autoantibodies are polyspecific, encompassing epitopes across the entire cTnI sequence, including the cardiac-specific amino terminal region.

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Keywords

anti-cTnI IgG
 
autoantibodies
 
autoimmune cohorts
 
autoimmune diseases
 
brain natriuretic peptide
 
cardiac-specific amino terminal region
 
clinical biomarkers
 
entire cTnI sequence
 
hepatitis C virus
 
human cardiac troponin-I
 
human cTnI amino acid sequence
 
IgG autoantibodies reactive
 
infectious disease cohorts
 
myocyte damage
 
normal blood donors
 
normal donor cohort
 
reactive samples
 
rheumatoid factor cohort
 
serum samples
 
systemic lupus erythematosus
 

Maciej Adamczyk