IgM-phosphorylcholine autoantibodies and outcome in acute coronary syndromes.
BACKGROUND
Antibodies against proinflammatory phosphorylcholine (anti-PC) seem to be protective and reduce morbidity. We sought to determine whether low levels of immunoglobulin-M (IgM) autoantibodies against PC add prognostic information in acute coronary syndromes (ACS).


METHODS
IgM anti-PC titers were measured in serum obtained within 24h of admission from 1185 ACS patients (median age 66 years, 30% women). We evaluated major acute cardiovascular events (MACE) and all-cause mortality short--(6 months), intermediate--(18 months) and long--(72 months) terms.


RESULTS
Low anti-PC titers were associated with MACE and all-cause mortality at all follow-up times. After adjusting for clinical variables, plasma troponin-I, proBNP and CRP levels, associations remained at all times with MACE, short and intermediate terms also with all-cause mortality. With anti-PC titers below median, adjusted hazard ratios at 18months were for MACE 1.79 (95% confidence interval [CI]: 1.31 to 2.44; p=0.0002) and for all-cause mortality 2.28 (95% CI: 1.32 to 3.92; p=0.003). Anti-PC and plasma CRP were unrelated and added to risk prediction.


CONCLUSIONS
Serum IgM anti-PC titers provide prognostic information above traditional risk factors in ACS. The ease of measurement and potential therapeutic perspective indicate that it may be a valuable novel biomarker in ACS.
Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. kenneth.caidahl@ki.se
Kenneth
K
Caidahl
Marianne
M
Hartford
Thomas
T
Karlsson
Johan
J
Herlitz
Knut
K
Pettersson
Ulf
U
de Faire
Johan
J
Frostegård
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis* / Q000628:therapy; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010767:Phosphorylcholine / Q000097:blood*; D011446:Prospective Studies; D012307:Risk Factors; D016896:Treatment Outcome
D001323:Autoantibodies; D015415:Biomarkers; D007075:Immunoglobulin M; D010767:Phosphorylcholine