CRP measurement: does the assay matter in hemodialysis patients?
BACKGROUND
The serum level of C-reactive protein, an acute-phase marker of systemic inflammation, has been shown to predict cardiovascular events in the general population and cardiovascular and total mortality in hemodialysis patients. High-sensitivity CRP assays (hs-CRP) have been used in numerous studies. We hypothesized that the level of CRP as measured by the conventional assay (c-CRP) would predict mortality in hemodialysis patients with an accuracy similar to that of high-sensitivity assays.


METHODS
In April 2001 CRP serum level was measured with both a conventional and a high-sensitivity assay in 102 prevalent hemodialysis patients. Mortality was prospectively monitored over 6 years.


RESULTS
49 patients (48%) died during follow-up. With both assays, almost 2/3 of patients had high CRP levels (> 1 mg/dl). Survival at 6 years was significantly lower in patients with high CRP levels, no matter which assay was used (31.5% for patients with high hs-CRP and 27.3% for patients with high c-CRP vs 48.4% for patients with low hs-CRP and 47.1% for patients with low c-CRP). Cardiovascular mortality was also higher in patients with high CRP levels, whatever the type of assay (conventional or high sensitivity) used. The correlation between the two tests was excellent.


CONCLUSIONS
CRP level, measured by a conventional inexpensive assay, is predictive of mortality in hemodialysis patients.
Kanaan
N
N
Department of Nephrology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium. nada.Kanaan@uclouvain.be
Goffin
E
E
Maisin
D
D
Struyven
J
J
Jadoul
M
M
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001530:Belgium / Q000453:epidemiology; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000097:blood* / Q000453:epidemiology / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry; D011379:Prognosis; D011446:Prospective Studies; D006435:Renal Dialysis; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013997:Time Factors; D055815:Young Adult
D015415:Biomarkers; D002097:C-Reactive Protein