YKL-40, a novel marker of cardiovascular complications, is related to kidney function in heart transplant recipients.
BACKGROUND
YKL-40 is an inflammatory glycoprotein involved in endothelial dysfunction and expressed in macrophages in the earliest lesions of atherosclerosis. Elevated serum YKL-40 levels are independently associated with the presence and extent of coronary artery disease and cardiovascular mortality. Because there are no data on heart transplant recipients and because they are prone to cardiovascular complications, the aim of this study was to assess YKL-40 in this population with particular attention to its relationship with endothelial damage. We studied 84 patients after heart transplantation. Healthy volunteers served as control subjects.


METHODS
Complete blood count, urea, creatinine, lipids, fasting glucose, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and iron status were studied with the use of standard laboratory methods. We assessed YKL-40, copeptin, markers of inflammation high sensitivity C-reactive protein (hsCRP) and interleukin (IL) 6, and markers of endothelial cell injury von Willebrand factor (vWF) and midkine with the use of commercially available assays.


RESULTS
Mean levels of YKL-40, IL-6, vWF, and hsCRP were significantly higher in heart allograft recipients than in the control group (P < .001). In univariate analysis, YKL-40 was related to kidney function (creatinine, r = 0.63 [P < .001]; estimated glomerular filtration rate, r = -0.44 [P < .001]), NT-proBNP (r = 0.45; P < .001), age (r = 0.33; P < .01), time after transplantation (r = 0.23; P < .05), copeptin (r = -0.42; P < .001), soluble transferrin receptor (r = 0.24; P < .05), hemoglobin (r = -0.42; P < .001), transferrin (r = -0.31; P < .01), haptoglobin (r = 0.39; P < .001), cystatin C (r = 0.55; P < .001), ejection fraction (r = -0.28; P < .05), New York Heart Association functional class (r = -0.41; P < .01), hsCRP (r = 0.26; P < .05), IL-6 (r = 0.23; P < .05), vWF (r = -0.40; P < .001), and midkine (r = 0.33; P < .01). In multivariate analysis, only creatinine was found to be a predictor of YKL-40 (β = 0.59; P = .02), explaining 56% of the variation in YKL-40 levels in heart allograft recipients.


CONCLUSIONS
YKL-40 may contribute to the enhanced risk of cardiovascular complications mainly owing to impaired renal function in patients after heart transplantation.
Department of Cardiovascular Surgery and Transplantology, Jagiellonian University Medical College, John Paul II Hospital, Cracow, Poland. Electronic address: piotr.przybylowski@uj.edu.pl.
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Przybyłowski
Department of Cardiovascular Surgery and Transplantology, Jagiellonian University Medical College, John Paul II Hospital, Cracow, Poland.
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Janik
Department of Cardiovascular Surgery and Transplantology, Jagiellonian University Medical College, John Paul II Hospital, Cracow, Poland.
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Wasilewski
Department of Internal Medicine and Angiology, Brothers Hospitallers' of St John of God Hospital, Cracow, Poland.
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E
Nowak
Medical Department, Medical College, Jagiellonian University, Cracow, Poland.
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Koźlik
2nd Department of Nephrology, Medical University of Bialystok, Poland.
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Małyszko
D054392:Adipokines / Q000097:blood*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood*; D000071451:Chitinase-3-Like Protein 1; D003327:Coronary Disease; D003404:Creatinine / Q000097:blood; D055316:Cystatin C; D005260:Female; D005919:Glomerular Filtration Rate; D006020:Glycopeptides / Q000097:blood; D016027:Heart Transplantation; D006801:Humans; D007249:Inflammation / Q000097:blood; D015850:Interleukin-6; D037102:Lectins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D051436:Renal Insufficiency, Chronic / Q000097:blood*; D066027:Transplant Recipients
D054392:Adipokines; D015415:Biomarkers; C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D055316:Cystatin C; D006020:Glycopeptides; D015850:Interleukin-6; D037102:Lectins; D010446:Peptide Fragments; C048197:copeptins; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein; D003404:Creatinine