Original Article Influence of Haemodialysis Membranes on p2-Microglobulin Kinetics: In Vivo and In Vitro Studies

Abstract. Amyloidosis of the P2-microglobulin (P2M) type is a recently recognised complication of dialysis. We studied plasma and ultrafiltrate P2M in 36 chronic haemodialysis patients. Long-term dialysis with stan-dard cuprophan membrane in non-oliguric patients and with the AN69 polyacrylonitrile membrane in oliguric patients resulted in lower plasma P2M concentrations (means ±SD, 24.4±6.6 and 33.0 + 8.2 ug/ml, respect-ively) than with cuprophan in oliguric patients (47.0 ± 13.2 ug/ml,/><0.01). In acute studies, plasma P2M (corrected for haemo-concentration) increased, although not significantly, during cuprophan dialysis (w=10) from 40.6+12.2 to 44.8 + 7.6 ug/ml and decreased during AN69 dialyis («=10) from 39.4±18.0 to 24.3±7.1 ug/ml (/><0.02). After 15 min ultrafiltration, P2M sieving coefficient in vivo was 0.33 for AN69 but near zero for cuprophan. Total mass transfer of P2M across the AN69 membrane during a 4-h dialysis was 142 ± 45.8 mg (n = 7). AN69, but not cuprophan, membrane fragments incubated in vitro with normal or uraemic plasma exhibited avid [125-1] P2M binding (respectively 12.9 % vs 0.47 % and 6.09 % vs 0.06 % of total P2M bound at 30 min, n = 6, P<0.001 for both). No in vitro generation of P2M from whole normal or uraemic blood could be demonstrated during incubation with either membrane. Correspondence and offprint requests to: Dr Johanna Zingraff, INSERM U. 90 and Departement de Nephrologie. Hopital Necker, 161 rue d