Immunohistological demonstration of lymphocyte surface antigens in postmortem lymphoid tissues

The postmortem stability of cell antigens has hardly been studied. Using monoclonal antibodies (mabs) we examined the postmortem detectability of lymphocyte surface antigens in different lymphoid organs by comparing two sensitive, immunohistological staining procedures. To quantify the probable degree of autolysis of the tissues a score system was applied by taking into consideration the postmortem age as well as the core temperature of the corpses. The antigens examined generally proved to be very resistant to autolytic influences. Differences were found when comparing different mabs and with regard to the type of lymphoid tissue. The loss of immunohistological reactions was most extensive in the spleen whereas tonsils showed almost no qualitative alterations in staining patterns. Reactivity of mabs with postmortem tissues decreased in the following order: Dako CD22 and anti-Leu 4, anti-Leu 3a, anti-Leu 7, Dako T8. The mabs anti-Leu 7 and Dako-T8 frequently failed to demonstrate their respective antigens but no correlation between the loss of staining and the degree of autolytic decomposition (our score) could be detected. In general, postmortem tissues as well as tissues shock frozen after delay are suitable for qualitative immunohistology of those cells characterized by the mabs applied. The APAAP-method proved unequivocally to be the superior staining technique.