Soluble and cell-associated forms of some yet to be identified factor in transfused blood which promotes solid tumor growth in mice.
OBJECTIVE
The mechanism underlying the immunomodulation caused by blood transfusion has yet to be elucidated. The aim of the present study was to determine whether the transfusion of a soluble or insoluble factor present in stored blood can induce immunomodulation, which would thereby promote solid tumor growth.


METHODS
C57Bl/6J mice were subcutaneously inoculated with B16-CG melanoma cells, which secrete beta-human chorionic gonadotropin (beta-hCG). Following inoculation, each of three different products of allogeneic and syngeneic blood were transfused on days 0 and 1: fresh whole blood, stored whole blood, and supernatants from the stored blood. Tumor growth was then monitored by measuring urinary beta-hCG. All mice were killed on day 15, and the tumor weight and volume were measured.


RESULTS
Transfusion of all allogeneic blood products enhanced tumor growth, as did the stored syngeneic whole blood. Neither fresh syngeneic blood nor the supernatant from stored syngeneic blood promoted tumor growth. Although the tumors were not visually detectable until day 10 after inoculation, by day 7 the levels of urinary beta-hCG were significantly higher in the mice that received allogeneic blood supernatant than in the mice that received saline.


CONCLUSIONS
A soluble alloantigen enhances solid tumor growth, as does an insoluble factor present in stored syngeneic whole blood. The immunomodulation associated with this factor begins to enhance tumor growth within 7 days after transfusion.
Department of Surgery, Akita University School of Medicine, 1-1-1 Hondo, Akita 010-8543, Japan.
Manabu
M
Okuyama
Satoru
S
Motoyama
Satoshi
S
Saito
Reijiro
R
Saito
Masakatsu
M
Nakamura
Hiroshi
H
Imano
Yoshihiro
Y
Minamiya
Jun-Ichi
J
Ogawa
D000818:Animals; D001774:Blood Chemical Analysis; D001793:Blood Preservation / Q000009:adverse effects; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000276:immunology / Q000652:urine; D006801:Humans; D007108:Immune Tolerance; D007155:Immunologic Factors; D007519:Isoantigens / Q000276:immunology; D008297:Male; D008546:Melanoma, Experimental / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D013997:Time Factors; D065227:Transfusion Reaction
D018997:Chorionic Gonadotropin, beta Subunit, Human; D007155:Immunologic Factors; D007519:Isoantigens