β-Thromboglobulin may not reflect platelet activation during haemodialysis with the HeprAN membrane

When blood passes through the extracorporeal circuit during haemodialysis (HD) undesirable effects including platelet degranulation and coagulation activation take place. β-thromboglobulin (β-TG) is a sensitive marker of platelet activation. The aim of this study was to investigate platelet degranulation and coagulation activation during HD with the heparin-coated dialysis membrane HeprAN.

Four HD sessions were evaluated in each of 12 chronic HD patients. None of the patients used oral warfarin, other anticoagulants or antiplatelet drugs. In the first session the HeprAN membrane or a conventional polyflux membrane was used in a randomized manner and thereafter alternately in a cross-over design, and 50% of the conventional dalteparin dose was given at start of HD. Prothrombin fragment 1 + 2 (PF1 + 2), β-TG and anti-factor Xa activity were measured repeatedly.

No dialysis sessions were terminated early due to clotting of the extracorporeal system. Activation of intravascular coagulation as assessed by change in PF1 + 2 during 4 hours of HD was the same with the two membranes. β-TG concentration decreased significantly during 4 hours of HD with the HeprAN membrane but remained stable with the polyflux membrane.

There were no differences in clotting scores or coagulation activation with the two membranes. The decrease in β-TG during HD with the HeprAN membrane suggests β-TG to be an inferior marker of platelet degranulation when using a heparin-coated dialysis membrane. A possible mechanism for the decline in β-TG concentration may be adherence of this heparin-binding protein to the heparin-coated dialysis membrane.