Polyacrylonitrile an 69 membrane

Hemodialysis is a safe procedure. Hypersensitivity during hemodialysis can sometimes be due to the membrane.
Risk factors
Concomitant use of ACE inhibitors.
Clinical manifestations (onset within 20 minutes after starting dialysis)
Major criteria: dyspnea, angioedema, burning/ heat sensation at the access site or throughout the body.
Minor criteria: urticaria, rhinorrhea, lacrimation, itching, abdominal cramps.
Diagnostic methods
Increased bradykinin in samples obtained from afferent blood line of patients.
Contact of plasma with negatively charged AN 69 membrane initiates the contact phase of coagulation and leads to the activation of the Hageman factor and conversion of prekallikrein to kallikrein, which cleaves bradykinin from the high molecular weight kininogen.
Normally kininogen is almost completely cleared by the kininases during its passage in the lung circulation. This does not occur in patients with ACE inhibitors; leading to bradykinin accumulation and development of anaphylactoid reactions.
Avoidance of the association of AN 69 membrane with ACE inhibitors.
Nevertheless, anaphylactoid reactions have been reported with AN 69 membranes without ACE inhibitor association.


  1. Tielemans C, Gastaldello K, Goldman M, Vanherweghem J.L, "Acute hemodialysis membrane-associated reactions", Nephrol. Dial. Transplant, 1996; 11 (S2): 112-5
  2. Verresen L, Fink E, Lemke H.D, Vanrenterghem Y, "Bradykinin is a mediator of anaphylactoid reactions during hemodialysis with AN 69 membranes", Kidney.Int., 1994; 45: 1497-1503

As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.