A review of allograft processing and sterilization techniques and their role in transmission of the human immunodeficiency virus

Human immunodeficiency virus (HIV) infection via vas cular organ and tissue transplantation is well docu mented. The majority of these transmissions occurred before the development of HIV antibody testing, which is now a routine screening tool used before organ and tissue procurement and transplantation. There exists what is commonly referred to as a "window" of sero negativity after HIV infection. Potential donors may be infectious with the HIV virus but not yet detected with available HIV antibody tests. Bone and soft tissue retrieval may be done in either a sterile or clean, non- sterile manner. Deep freezing and freeze-drying (lyoph ilization) are two commonly used modes of preserving bone and soft tissue allografts. In 1985, a screened donor who was in the window of seronegativity underwent vascular organ and mus culoskeletal tissue harvest. The bone and soft tissue procured underwent a variety of processing and pres ervation techniques. There have been no known cases of HIV transmission from the processed freeze-dried tissues. Evidence now exists that early HIV infection, before HIV antibody production, may be the most infectious period. The HIV antigen testing may allow earlier detec tion of an infectious donor, thus closing the window of seronegativity. It is unknown whether this nontransmis sion of HIV to the recipients of the processed and freeze-dried tissue was due to the processing or the nature of the tissue itself.