The purpose of this study is to investigate the effect of transfusion of allogeneic (homologous) red cells on the immunologic parameters such as T-cells as well as natural killer cell count/function, various interleukins, TNF alpha and other immunologic relevant parameters on postoperative day 1,3 and 5-7 in patients undergoing spine surgery.

Inclusion Criteria:

• Age > 18 - < 60 years
• Patients underwent elective spine surgery
• ASA classification 1-3

Exclusion Criteria:

• Patients who have the concomitant condition
• Cancer
• History of heart disease including, heart failure, coronary artery disease, hypertension treated with more than one medicament.
• Serum creatinine > 1.5 mg/dL
• Stroke, neurologic and mental deficits, epilepsy
• General or local infection (site of surgery),
• Coagulation disorders.
• Intraoperative massive bleeding
• Infection of the spine
• Rheumatoid arthritis
• Patients who had either of the following drug (aspirin, methotrexate, cyclosporine, qualaquin)

Patients underwent elective spine surgery