Ethylene oxide-type hypersensitivity reactions in G-CSF mobilized, peripheral blood hematopoietic progenitor cell donors and review.

Background: Ethylene oxide (EtO) is a volatile, ringed toxic ether used to sterilize heat-labile plastics including apheresis sets. In the 1980s, EtO-associated severe hypersensitivity reactions during hemodialysis led to widespread adoption of alternative sterilization for dialysis kits but not apheresis tubing sets. We now report several cases of EtO-type hypersensitivity reactions in autologous donors undergoing hematopoietic progenitor cell collection (HPCC).

Materials And Methods: A 10-year retrospective review of allergic EtO-type reactions in adults undergoing HPCC on the COBE Spectra and SPECTRA Optia was performed. Donor medical history and absolute eosinophil counts were compared between cases and 34 HPCC controls. Published EtO reactions during extracorporeal procedures were reviewed with statistical analysis. Graphics and statistics were performed using commercial software.

Results: Three autologous HPCC donors experienced EtO-type reactions within 15 min of initiating HPCC, for a 10-year incident rate of 0.08% per procedure and 0.18% per donor. All three reactions occurred using the Spectra Optia and IDL tubing set, for an Optia/IDL specific rate of 0.2% per procedure and 0.5% per donor. There was no correlation between EtO reactions, eosinophil counts, or saline prime dwell times. No patient had classic predisposing risk factors for EtO hypersensitivity. Two patients required medical intervention whereas the third responded by pausing the procedure and slowing the inlet rate.

Conclusion: EtO-type hypersensitivity reactions can be observed during HPCC, especially with the Optia IDL tubing set. EtO reactions may be missed due to their rarity and staff unfamiliarity with this clinical entity.