Assessment of Infection Risk Among Recipients of Recalled Human Tissue for Transplantation

Background: In 2006 there were two major human tissue recalls. One tissue-bank recovered tissue from donors who did not meet eligibility requirements; in addition, blood submitted for screening had not come from the persons from whom the linked tissues had been obtained. At the other tissue bank there was concern regarding blood-screening practices and manufacturing practices. Recipients were advised to be tested for blood-borne viruses (BBV) and syphilis.
Objective: To describe: 1) what infectious agents have been transmitted by musculoskeletal tissues, 2) how implicated tissue was processed and stored, 3) survival of BBV under different conditions, 4) risks associated with implanted tissue stored at room temperature for 30 days and/or processed using sporicidal methods.
Methods: A literature review was conducted to identify what infectious agents have been transmitted through musculoskeletal tissue and kinetics and determinants of BBV survival. Procedures taken to reduce risk of disease transmission were reviewed, as well as tissue storage conditions. Tissue processors involved in the recalls were contacted and asked to provide validation data on reducing/eliminating infectious agents.

Results: Infectious agents transmitted through implanted musculoskeletal tissue include: bacteria (Gram-positive, Gram-negative, Clostridia, mycobacteria) and viruses (human immunodeficiency, hepatitis C). Transmissions of BBV occurred only from frozen tissue that was processed using aseptic, non-sporicidal processing methods. Screening (medical/social history, blood/serum assays and microbiological testing) has limitations. Most tissue processors contacted did not provide validation data; Only one tissue processor provided validation data for their sterilization process.

Conclusions: Tissue safety is greatly enhanced if tissue has been processed using a validated sterilizing process. No BBV transmission has occurred in patients who received tissue stored at room temperature. Patients and physicians should know how their tissue was processed and stored. If a validated sterilizing method was used, patients can confidently be reassured. Validation data for tissue-processors should be published.