Transition from Secondary Blood Test to Nucleic Acid Amplification for Safe Allograft Transplantation

Given the incubation period of viral diseases, a secondary blood test should be performed at least 3-6 months after the first test to ensure the safety of allogenic bone grafts obtained from living donors in some tissue banks. The allograft is discarded if a secondary blood test was unavailable. The secondary blood test can be replaced with a nucleic acid amplification test (NAT) to reduce the discarded allograft. The purpose of this study was to analyze the comparative efficiency of secondary blood test and NAT to determine the donor suitability of allogenic bone grafts.

Allogenic bones were retrieved from 452 living donors between January 2013 and December 2019. A secondary blood test was conducted in 182 patients and NAT was performed in 270 patients. The average age of donors was 69 years (range, 33-87 years). They included 86 men and 366 women. The initial blood tests including hepatitis B, hepatitis C, AIDS, and syphilis were conducted before retrieving grafts. The results were analyzed after the secondary blood test was performed at least 3 to 6 months after the first test because of the incubation period of the viral diseases. NAT was performed within 2 months after the first blood test.

Sixty-seven of the 452 cases (14.8%) were discarded. In the secondary blood test group, 50 out of 182 cases (27.4%), and in the NAT group, 17 out of 270 cases (6.3%) were discarded. None of the 132 donors tested positive in the secondary blood test after testing negative in the first test.

It is extremely rare that the secondary blood test yields positive results in donors who tested negative in the initial test. However, quite a few grafts are discarded only because the secondary blood test is not available. In terms of economics and ethics, the secondary blood test may not be necessary or if required, a single test such as NAT for infectious diseases may be performed to determine donor suitability of allogenic bone.