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THE EFFECT OF BLOOD TRANSFUSION ON IMMUNE FUNCTION Since homologous blood is never given to normal volunteers, the effect of blood transfusion on immune function in normal man is unknown. In patients who receive homologous blood, changes in immune response are evaluated in the context of the disease for which the blood is given and extrapolated to the effect of blood in the absence of disease. Changes in immunity consistently following transfusion for a variety of diseases can be assumed to be due to the transfusion and not to the diseases. Changes in immune function following transfusion with autologous blood or washed/filtered homologous blood can be compared to patients who are receiving routinely prepared homologous blood. The blood is given within the context of a surgical procedure as a consequence of operative blood loss which is due to trauma and trauma itself is associated with changes in immune function. In Vitro Lymphocyte Responsiveness Generally, inhibition of lymphocyte response to a given antigen or mitogen measured by incorporation of tritiated thymidine is accompanied by inhibition of response to all antigens and mitogens. Surgery, anesthesia, blood loss and blood transfusion cause lymphocyte suppression in clinical studies. Isolating the effect of homologous blood transfusion from the surgery, anesthesia and blood loss is not easy. In vitro lymphocyte responses decline in proportion to the magnitude of the procedure and in proportion to the amount of blood lost. Certain anesthetic agents, notably ether and cyclopropane, are associated with more profound suppression of immune function than halothane and nitrous oxide, for example (1). Patients with malignancies have low lymphocyte responses and declines with surgery are more precipitous than for patients without malignancies. Operated patients who receive homologus blood have declines in lymphocyte responsiveness compared to untransfused patients undergoing the same procedure. Thorough well-controlled studies have also observed the opposite, causing Munster et al. to comment that continued investigation " into the effect of PHA and ConA on post-traumatic lymphocyte transformation in many laboratories has produced no conclusive and repeatable pattern." (2) Prolonged depression in in vitro lymphocyte responsiveness is noted within hours of surgery and recovers over the next several days. The inhibition is due to both intrinsic and extrinsic factors since lymphocyte responsiveness can be partially restored by testing in plasma from normal blood donors. Homologous blood transfusion adds to the depressed state of the lymphocytes, but may cause stimulation in unoperated patients. The in vivo counterpart of in vitro testing of lymphocytes is delayed cutaneous hypersensitivity to antigens. Delayed Cutaneous Hypersensitivity There exists a correlation between in vivo and in vitro lymphocyte testing and preoperative evaluation of in vivo lymphocyte function is predictive of postoperative infection and subsequent course after surgery. Anergy is associated with low serum albumin and reduced polymophonuclear neutrophil chemotaxis. Patients with gastrointestinal bleeding, recipients of homologous blood, are often anergic (3). Sepsis following surgery for gastrointestinal bleeding is more common, hospital stay longer, and mortality higher in anergic patients. Patients who are initially anergic and remain anergic usually die.
DOI link for THE EFFECT OF BLOOD TRANSFUSION ON IMMUNE FUNCTION Since homologous blood is never given to normal volunteers, the effect of blood transfusion on immune function in normal man is unknown. In patients who receive homologous blood, changes in immune response are evaluated in the context of the disease for which the blood is given and extrapolated to the effect of blood in the absence of disease. Changes in immunity consistently following transfusion for a variety of diseases can be assumed to be due to the transfusion and not to the diseases. Changes in immune function following transfusion with autologous blood or washed/filtered homologous blood can be compared to patients who are receiving routinely prepared homologous blood. The blood is given within the context of a surgical procedure as a consequence of operative blood loss which is due to trauma and trauma itself is associated with changes in immune function. In Vitro Lymphocyte Responsiveness Generally, inhibition of lymphocyte response to a given antigen or mitogen measured by incorporation of tritiated thymidine is accompanied by inhibition of response to all antigens and mitogens. Surgery, anesthesia, blood loss and blood transfusion cause lymphocyte suppression in clinical studies. Isolating the effect of homologous blood transfusion from the surgery, anesthesia and blood loss is not easy. In vitro lymphocyte responses decline in proportion to the magnitude of the procedure and in proportion to the amount of blood lost. Certain anesthetic agents, notably ether and cyclopropane, are associated with more profound suppression of immune function than halothane and nitrous oxide, for example (1). Patients with malignancies have low lymphocyte responses and declines with surgery are more precipitous than for patients without malignancies. Operated patients who receive homologus blood have declines in lymphocyte responsiveness compared to untransfused patients undergoing the same procedure. Thorough well-controlled studies have also observed the opposite, causing Munster et al. to comment that continued investigation " into the effect of PHA and ConA on post-traumatic lymphocyte transformation in many laboratories has produced no conclusive and repeatable pattern." (2) Prolonged depression in in vitro lymphocyte responsiveness is noted within hours of surgery and recovers over the next several days. The inhibition is due to both intrinsic and extrinsic factors since lymphocyte responsiveness can be partially restored by testing in plasma from normal blood donors. Homologous blood transfusion adds to the depressed state of the lymphocytes, but may cause stimulation in unoperated patients. The in vivo counterpart of in vitro testing of lymphocytes is delayed cutaneous hypersensitivity to antigens. Delayed Cutaneous Hypersensitivity There exists a correlation between in vivo and in vitro lymphocyte testing and preoperative evaluation of in vivo lymphocyte function is predictive of postoperative infection and subsequent course after surgery. Anergy is associated with low serum albumin and reduced polymophonuclear neutrophil chemotaxis. Patients with gastrointestinal bleeding, recipients of homologous blood, are often anergic (3). Sepsis following surgery for gastrointestinal bleeding is more common, hospital stay longer, and mortality higher in anergic patients. Patients who are initially anergic and remain anergic usually die.
THE EFFECT OF BLOOD TRANSFUSION ON IMMUNE FUNCTION Since homologous blood is never given to normal volunteers, the effect of blood transfusion on immune function in normal man is unknown. In patients who receive homologous blood, changes in immune response are evaluated in the context of the disease for which the blood is given and extrapolated to the effect of blood in the absence of disease. Changes in immunity consistently following transfusion for a variety of diseases can be assumed to be due to the transfusion and not to the diseases. Changes in immune function following transfusion with autologous blood or washed/filtered homologous blood can be compared to patients who are receiving routinely prepared homologous blood. The blood is given within the context of a surgical procedure as a consequence of operative blood loss which is due to trauma and trauma itself is associated with changes in immune function. In Vitro Lymphocyte Responsiveness Generally, inhibition of lymphocyte response to a given antigen or mitogen measured by incorporation of tritiated thymidine is accompanied by inhibition of response to all antigens and mitogens. Surgery, anesthesia, blood loss and blood transfusion cause lymphocyte suppression in clinical studies. Isolating the effect of homologous blood transfusion from the surgery, anesthesia and blood loss is not easy. In vitro lymphocyte responses decline in proportion to the magnitude of the procedure and in proportion to the amount of blood lost. Certain anesthetic agents, notably ether and cyclopropane, are associated with more profound suppression of immune function than halothane and nitrous oxide, for example (1). Patients with malignancies have low lymphocyte responses and declines with surgery are more precipitous than for patients without malignancies. Operated patients who receive homologus blood have declines in lymphocyte responsiveness compared to untransfused patients undergoing the same procedure. Thorough well-controlled studies have also observed the opposite, causing Munster et al. to comment that continued investigation " into the effect of PHA and ConA on post-traumatic lymphocyte transformation in many laboratories has produced no conclusive and repeatable pattern." (2) Prolonged depression in in vitro lymphocyte responsiveness is noted within hours of surgery and recovers over the next several days. The inhibition is due to both intrinsic and extrinsic factors since lymphocyte responsiveness can be partially restored by testing in plasma from normal blood donors. Homologous blood transfusion adds to the depressed state of the lymphocytes, but may cause stimulation in unoperated patients. The in vivo counterpart of in vitro testing of lymphocytes is delayed cutaneous hypersensitivity to antigens. Delayed Cutaneous Hypersensitivity There exists a correlation between in vivo and in vitro lymphocyte testing and preoperative evaluation of in vivo lymphocyte function is predictive of postoperative infection and subsequent course after surgery. Anergy is associated with low serum albumin and reduced polymophonuclear neutrophil chemotaxis. Patients with gastrointestinal bleeding, recipients of homologous blood, are often anergic (3). Sepsis following surgery for gastrointestinal bleeding is more common, hospital stay longer, and mortality higher in anergic patients. Patients who are initially anergic and remain anergic usually die.
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