Apoptosis in the human thymus in sudden and delayed death.

We counted apoptotic thymic cortical lymphocytes in semi-thin plastic sections of 266 human autopsy thymuses. The decreased patients included in the study were all aged less than 40 yrs and all died within 72 hrs of the onset of symptoms. Based on published data on animal and human material it was anticipated that individuals dying within 3 hrs of the onset of their fatal condition--"sudden deaths"--would have low apoptotic counts and those dying 3 to 72 hrs after the onset of their fatal condition--"delayed deaths"--would have elevated counts. Results showed that the sudden death group did have low apoptotic counts (mean 0.24 +/- 0.03% Standard Error of the Mean (SEM); n = 208) and the delayed death group did have significantly higher counts (mean 17.94 +/- 3.38% SEM; n = 58; p < 0.001). However, there were a number of cases in the latter group with low counts (n = 19). All of these patients had suffered injuries or clinical conditions that have been shown by others to be capable of interfering with the production of cortisol. As elevated cortisol is a major cause of apoptosis in thymic cortical lymphocytes, any such interference might prevent elevated apoptotic counts of thymic cortical lymphocytes.