In vitro immunosuppressive activity of soluble HLA class I and Fas ligand molecules: do they play a role in autologous blood transfusion?
BACKGROUND
The immunomodulatory effects of allogeneic blood transfusion may contribute to a poor prognosis in patients with cancer who are undergoing surgery, and clinical trials have been carried out to investigate whether these patients would benefit from autologous blood donation. As the immunomodulatory effects of allogeneic blood transfusion have been related to soluble molecules released from residual WBCs during storage, the in vitro immunomodulatory activity of soluble molecules detected in supernatants from stored autologous blood was evaluated.


METHODS
Blood was donated by four healthy volunteers. Packed WBC-reduced RBCs were obtained and stored for 30 days, and supernatants were collected. FFP and serum were also obtained. The concentration of soluble molecules was determined by immunoenzymatic assays. The in vitro immunomodulatory activity of undiluted blood component supernatant was assessed by antigen-specific cytotoxic T-cell activity and mixed lymphocyte reactions in autologous combinations and by apoptosis induction in Fas+ cells.


RESULTS
The concentrations of soluble Fas-ligand and HLA class I molecules were higher in packed RBCs than in WBC-reduced RBCs, FFP, and serum. Undiluted supernatants of packed RBCs strongly inhibited functional assays and induced apoptosis in Fas+ cells. The immunomodulatory effects were correlated with the amount of soluble Fas ligand and HLA class I molecules.


CONCLUSIONS
The results of the present study are comparable with those already reported in allogeneic blood components, and they indicate that undiluted supernatants of autologous blood components may exert immunosuppressive effects in vitro.
Ghio
M
M
Departments of Internal, University of Genoa, Genoa, Italy.
Contini
P
P
Mazzei
C
C
Merlo
A
A
Filaci
G
G
Setti
M
M
Indiveri
F
F
Puppo
F
F
D000328:Adult; D017209:Apoptosis / Q000187:drug effects; D001804:Blood Transfusion, Autologous; D003601:Cytotoxicity Tests, Immunologic; D017707:Erythrocyte Transfusion; D004912:Erythrocytes / Q000276:immunology / Q000378:metabolism; D053222:Fas Ligand Protein; D015395:Histocompatibility Antigens Class I / Q000097:blood / Q000276:immunology* / Q000494:pharmacology*; D006801:Humans; D007143:Immunoglobulin Heavy Chains / Q000032:analysis / Q000276:immunology / Q000494:pharmacology; D007166:Immunosuppressive Agents / Q000097:blood / Q000276:immunology / Q000494:pharmacology; D019169:Jurkat Cells; D007937:Leukapheresis; D007959:Lymphocyte Culture Test, Mixed; D008562:Membrane Glycoproteins / Q000097:blood / Q000276:immunology* / Q000494:pharmacology*; D012995:Solubility; D001613:beta 2-Microglobulin / Q000032:analysis / Q000276:immunology / Q000494:pharmacology
C505661:FASLG protein, human; D053222:Fas Ligand Protein; D015395:Histocompatibility Antigens Class I; D007143:Immunoglobulin Heavy Chains; D007166:Immunosuppressive Agents; D008562:Membrane Glycoproteins; D001613:beta 2-Microglobulin