NDT Advance Access originally published online on February 22, 2007
Nephrology Dialysis Transplantation 2007 22(6):1685-1689; doi:10.1093/ndt/gfm068
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Autoantibodies against N-homocysteinylated proteins in patients on long-term haemodialysis
1
Gowacki3awa Tracz1
1Institute of Cardiology, Jagiellonian University School of Medicine, Cracow, 2Haemodialysis Unit Miechow, Miechow, 3Department of Environmental Chemistry, University of 
odz, odz and 4Department of Endocrinology, Jagiellonian University School of Medicine, Cracow, Poland
Correspondence and offprint requests to: Anetta Undas, MD, PhD, Institute of Cardiology, Jagiellonian University School of Medicine, 80 Pradnicka St.31-202 Cracow, Poland. Email: mmundas{at}cyf-kr.edu.pl
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Abstract |
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Background. Autoantibodies against N
-homocysteinylated (N-Hcy) proteins at high titres have been demonstrated in patients with premature coronary artery disease (CAD) and stroke. Since recently, elevated N-Hcy-proteins levels have been reported in haemodialysis patients, we sought to investigate whether anti-N-Hcy-protein antibodies occur in such subjects and if they are associated with cardiovascular risk.
Methods. We studied 43 patients, aged 27–89 (mean 58.8) years, dialysed for, on average, 50 months and 31 age- and sex-matched healthy controls. IgG antibodies against N-Hcy-albumin and -haemoglobin were determined using an in-house enzyme-linked immunosorbent assay.
Results. Haemodialysis patients had higher plasma tHcy (23.18 ± 1.37 vs 13.51 ± 0.64; P < 0.0001), serum folate (29.7 ± 6.9 vs 9.9 ± 3.8 nmol/l; P < 0.0001) and anti-N-Hcy-albumin and -haemoglobin antibodies (absorbancy at 490 nm: 0.39 ± 0.22 vs 0.34 ± 0.12; P = 0.03 and 0.60 ± 0.31 vs 0.42 ± 0.09; P < 0.0001, respectively) than controls. Levels of anti-N-Hcy-albumin antibodies, but not those against haemoglobin, correlated negatively with the duration of haemodialysis (r = –0.39; P = 0.01). This correlation disappeared after a 6-month follow-up. Haemodialysis patients treated with folic acid on a long-term basis had similar levels of anti-N-Hcy-albumin and -haemoglobin antibodies compared with the minority which denied taking this vitamin (absorbancy A490: 0.35 ± 0.22 vs 0.38 ± 0.05; P = 0.5 and 0.63 ± 0.30 vs 0.51 ± 0.11; P = 0.4, respectively).
Conclusions. Our study shows that an autoimmune response to anti-N-Hcy-proteins occurs in patients on maintenance haemodialysis and is more pronounced than in healthy subjects.
Keywords: antibodies; haemodialysis; homocysteine; protein homocysteinylation
Received for publication: 14.12.06
Accepted in revised form: 19. 1.07