Investigation of annexin V binding to lymphocytes after extracorporeal photoimmunotherapy as an early marker of apoptosis.
BACKGROUND
Induction of programmed cell death is assumed to be a possible effect of extracorporeal photoimmunotherapy (ECPI).


OBJECTIVE
In the present study lymphocytes of patients with cutaneous T cell lymphoma undergoing ECPI were investigated for early apoptotic events.


METHODS
Annexin V, known for its selective affinity to phospholipids, was used to detect early phases of apoptosis. Simultaneous staining with propidium iodide binding to DNA allowed detection of late apoptotic/necrotic cells.


RESULTS
At 1 h after ECPI, an increase in early apoptotic cells was found indicating a direct effect of ECPI. At 20 h after each ECPI session, a delayed increase in the number of apoptotic lymphocytes was observed in early apoptotic annexin-stained cells and in late apoptotic cells, whereas in nonirradiated cells no remarkable changes were found. Apoptosis was confirmed by altered light scattering properties and DNA fragmentation.


CONCLUSIONS
The apoptotic cell death of reinfused lymphocytes is supposed to be a therapeutic effect of ECPI.
Gerber
A
A
Institute of Immunology, Otto von Guericke University, Magdeburg, Germany. anneget.gerber@medizin.uni-magdeburg.de
Bohne
M
M
Rasch
J
J
Struy
H
H
Ansorge
S
S
Gollnick
H
H
D000368:Aged; D017304:Annexin A5 / Q000378:metabolism*; D017209:Apoptosis; D053938:DNA Fragmentation; D004273:DNA, Neoplasm / Q000235:genetics; D004587:Electrophoresis, Agar Gel; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007167:Immunotherapy; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism*; D016410:Lymphoma, T-Cell, Cutaneous / Q000378:metabolism / Q000473:pathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010789:Phototherapy; D011485:Protein Binding; D013997:Time Factors
D017304:Annexin A5; D004273:DNA, Neoplasm