Association of aminothiols with the clinical outcome in hemodialysis patients: comparison of chromatography and immunoassay for homocysteine determination.
BACKGROUND
Controversial results on hyperhomocysteinemia and cardiovascular risk in hemodialysis (HD) could be due in part to the methodology used for homocysteine (Hcy) determination.


OBJECTIVE
The aim of this study was to compare the influence of the method used for Hcy determination (chromatography or immunoassay) with regard to the association of Hcy with cardiovascular mortality rate in HD patients in a 3-year prospective study.


METHODS
A total of 162 patients undergoing HD were included in a cohort study. Baseline Hcy levels were measured by HPLC and fluorescence polarization immunoassay (FPIA). Cysteine and cysteinylglycine were determined simultaneously with Hcy measurement by HPLC.


RESULTS
Hcy levels obtained with both methods were highly correlated (r(2)=0.927, p<0.0001). An increased relative risk (RR) for cardiovascular mortality (n=31) was found between the highest against lowest tertile of Hcy for both HPLC (RR 2.74, 95% CI 1.07-7.02; p<0.05) and FPIA (RR 2.76, 95% CI 0.99-7.70; p=0.05). Interestingly, increased cysteine (> or =452 micromol/L) and cysteinylglycine (> or =36.6 micromol/L) levels were associated with a decreased RR of non-cardiovascular death (n=26) (RR 0.27, 95% CI 0.09-0.79; p=0.02) for cysteine and (RR 0.28, 95% CI 0.09-0.90; p=0.03) for cysteinylglycine when compared to the first tertile.


CONCLUSIONS
This study demonstrated an increased risk of cardiovascular mortality in HD patients with Hcy values in the third tertile, independent of the method used. HPLC offers the advantage of simultaneous determination of other aminothiols that appear to be associated with non-cardiovascular mortality.
Badiou
Stéphanie
S
Biochemistry Laboratory, Lapeyronie University Hospital, Montpellier, France.
Terrier
Nathalie
N
Jaussent
Isabelle
I
Naudin
Estelle
E
Maurice
François
F
Dupuy
Anne-Marie
AM
Leray-Moragues
Hélène
H
Rivory
Jean-Pierre
JP
Delcourt
Cécile
C
Canaud
Bernard
B
Cristol
Jean-Paul
JP
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002318:Cardiovascular Diseases / Q000175:diagnosis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D015331:Cohort Studies; D005260:Female; D016231:Fluorescence Polarization Immunoassay / Q000379:methods*; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000175:diagnosis*; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D013438:Sulfhydryl Compounds / Q000032:analysis
D013438:Sulfhydryl Compounds; D006710:Homocysteine