Anaphylaxis during hemodialysis associated with a polysulfone membrane: evidence from basophil activation testing

Dialyzer-associated anaphylaxis is an uncommon but serious complication of hemodialysis.Although severe anaphylaxis is rare, milder hypersensitivity reactions are likely underrecognized and frequently misattributed to cardiopulmonary or volume-related causes.In clinical practice, the diagnosis is often inferred indirectly from symptom resolution after dialyzer substitution rather than confirmed by immunologic testing.Serum tryptase is widely used as a marker of mast cell activation in anaphylaxis; however, its diagnostic utility is limited in patients with chronic kidney disease (CKD), in whom baseline tryptase levels may be chronically elevated due to reduced renal clearance.A patient with advanced CKD developed acute anaphylaxis with respiratory failure and hypotension during the initial hemodialysis session using a polysulfone-based dialyzer, requiring endotracheal intubation.Reexposure during a subsequent session reproducibly elicited the same reaction, strongly implicating dialyzer-associated anaphylaxis.Given the limitations of serum tryptase and the indirect nature of membrane substitution alone, a membrane-specific immunologic evaluation was pursued.Basophil activation testing (BAT) demonstrated polysulfone-specific basophil activation with upregulation of CD63 and CD203c, confirming immediate hypersensitivity.To our knowledge, this represents the first reported case in Korea of dialyzer-associated anaphylaxis immunologically confirmed by BAT.Using this case as a framework, we review the clinical spectrum and immunologic mechanisms of dialyzer-associated hypersensitivity and highlight the complementary diagnostic role of BAT in enabling definitive diagnosis and safe continuation of hemodialysis.