Delta-9-Tetrahydrocannabinol (D-9-THC) alter the innate immunity expected to induce immediate early events in surface marker profiles of circulating leukocytes. Methods: Blood samples of 100 patients were taken before, 1 day after and 2 days after prostectomy and subjected to flow cytometric analysis. The patients were separated into two groups - 50 patients got 8 times D-9-THC, the other 50 patients got a placebo product. D-9-THC-related changes in surface antigen expression were compared to the findings of the placebo group. Results: Medians of the most NK-cell surface antigens like CD161 and Va24 and the most T-lymphocytes surface antigens like CD4, CD8, CD3 were not found to be different in both groups, 48 h after surgery. Also the monocytic CD14 were similarly expressed in both groups before and after trauma. The pathogen receptors TLR2 and TLR4 were more upregulated by D-9-THC treatment. The death receptor CD95 and those two epitopes - DX-2 and APO-1 - were more upregulated on all cells and subpopulations by D-9-THC-patients than placebo. The B7 moleclues CD80, CD86 and the dendritic cell activation antigen CD83 decreased after surgery by D-9-THC-treatment. Conclusions: The death receptor epitope CD95FITC = APO-1 = Fas is increased in patients with systemic inflammatory response syndrome (SIRS) and our findings show an increase of APO-1. The conclusion is that the D-9-THC treated patients sicken more often than untreated patients. Also the decrease of the costimulation factors of B7-complex CD80 and CD86 or the dendritic cell activation antigen implicate a suppression of the immune system and therefore a higher risk to sicken more often
