Acute-Phase Proteins during Hemodialysis: Correlations with Serum Interleukin-1β Levels and Different Dialysis Membranes

The effects of hemodialysis (HD) on the levels of serum amyloid A (SAA), C-reactive protein (CRP) and interleukin-1β (IL-1β) were studied in 8 patients. Bicarbonate dialysate was used exclusively, and three different membranes, Cuprophan® (CU), cellulose acetate (CA), and polymethylmetachrylate (PMMA) were compared. The SAA levels increased significantly with each membrane. With CU, they rose from 4.0 ± 2.0 (mg/l, mean ± SEM) to 9.6 ± 2.8 at 60 min and to 15.0 ± 4.9 at 240 min. The values with CA were 3.8 ± 2.1,15.3 ± 5.6, and 23.8 ± 3.9; and with PMMA 2.4 ± 1.3,12.1 ± 5.6, and 12.1 ± 5.9, respectively. The alterations of SAA neither correlated with the weight loss nor the increase of serum albumin during dialysis. The CRP values showed insignificant changes. The IL-1β levels rose with CU from 87 ± 18 (ng/l) to 155 ± 33 at 60 min and to 172 ± 47 at 240 min. With CA, the values were 67 ± 14, 198 ± 46, and 121 ± 23, and with PMMA 63 ± 13,246 ± 93, and 211 ± 86, respectively. These results did not correlate with the effects of the membranes on complement activation. It is concluded that the release of cytokines during HD apparently leads to a rapid synthesis of acute-phase proteins as a sign of inflammation. Thus, SAA may be used as one indicator of the biocompatibility of HD treatment.