Validation of Serological Testing for Anti-Treponema pallidum from Postmortem Blood on the Siemens-BEP(®)-III...

Infectious disease marker testing is obligatory for the release of human tissue for transplantation. Most CE-marked tests are not validated for postmortem blood. In a previous study we have validated the testing for anti-HIV-1/2, anti-HCV, HBsAg, and anti-HBc. Here, we present the validation of testing for antibodies against T. pallidum, which is the last marker obligatory for tissue release for transplantation.

17 samples of postmortem sera and 10 samples of both pre-und postmortem sera were obtained from cornea donors and tested for anti-T. pallidum on the Siemens-BEP-III-System. These sera were spiked with anti-T. pallidum-positive standard sera in concentrations which give low- and high-positive results at the respective dilution.

Two of the unspiked postmortem sera were false-positive most likely due to intense hemolysis (free hemoglobin > 50 mg/dl). Of the 25 negative postmortem sera, none of the spiked samples was false-negative after 0, 24 and 60 h.

There is no indication that postmortem samples give false-negative or false-positive results with the test system and test kits used in cases of low hemolysis. The procedure described might serve as a model for validating other test kits on postmortem samples.