Adsorption characteristics of erythropoietin in two β2-microglobulin absorption systems: a preliminary in vitro study using FILTOR® and Lixelle®.

PURPOSE: To compare the erythropoietin adsorption characteristics of two adsorption devices, Lixelle® and FILTOR®, used for the treatment of dialysis-related amyloidosis, using bovine serum.

METHODS

Three recirculating perfusion studies were performed using bovine serum containing recombinant human erythropoietin (epoetin beta; EPO), darbepoetin alfa (DA), or epoetin beta pegol (C.E.R.A.). Because direct quantitative assays for DA and C.E.R.A. were unavailable, and it was difficult to obtain suitable measurement systems for these agents, they were evaluated using an erythropoietin immunoassay based on assay cross-reactivity.

RESULTS

In the EPO perfusion test (n = 3), the 4-h EPO removal rate was 18.7 ± 3.2% in the Lixelle® group and 53.0 ± 3.1% in the FILTOR® group (p < 0.05). In the DA perfusion test (n = 3), the 4-h removal rate based on erythropoietin immunoassay measurements was 3.3 ± 1.5% in the Lixelle® group and 31.0 ± 6.1% in the FILTOR® group (p < 0.05). In the C.E.R.A. perfusion test (n = 3), the corresponding removal rates were 0.3 ± 0.6% and 1.3 ± 2.3%, respectively, with no significant difference (p = 0.5351).

CONCLUSIONS

The FILTOR® adsorption device showed greater reductions in erythropoietin concentration than the Lixelle® device in experiments using EPO. A similar trend was observed for DA, whereas no apparent difference was observed for C.E.R.A. Because DA and C.E.R.A. were evaluated using assay cross-reactivity, and quantitative assessment was limited by the sampling strategy, these findings should be interpreted with caution.