The effect of unmodified or prestorage white cell-reduced allogeneic red cell transfusions on the immune responsiveness in orthopedic surgery patients

A randomized control trial for evaluation of transfusion related immuno-modulation in patients with meningioma

BACKGROUND

Blood transfusion necessity in neurosurgery varies based on surgical type, blood loss, and patient anemia. Leukocytes in red blood cells (RBCs) component release pro-inflammatory cytokines during storage, contributing to transfusion-related immunomodulation (TRIM). Our aim was to examine the impact of the leukocyte content in transfused PRBCs on patients undergoing neurosurgery for meningioma tumours.

STUDY DESIGN AND METHODS

This prospective randomized controlled trial conducted from 2018 to 2020 by dividing patients randomly into non-leukoreduced (NLR) (n = 65) and leuko-reduced (LR) (n = 65) groups based on PRBCs received during surgery and hospital stay. Hospital and ICU stays, mechanical ventilation duration, and postoperative bacterial infections were observed. Hematological parameters and cytokine levels (IL-10, INF-gamma, and FAS-L) were assessed at pre-transfusion, 24 h, and 7 days post-transfusion. Data analysis included Mann-Whitney U test, Friedman test, Fisher's chi-square test, with statistical significance at p < 0.05.

RESULTS

In our study, ICU and hospital stay duration showed no significant difference (p = 0.06) between groups. However, NLR group had longer mean mechanical ventilation (18 ± 40.1 h) than the LR group (12.8 ± 8.6 h). Both groups showed statistically significant increase in Fas-L level on days 1 and 7 (p < 0.05). The IL-10 levels rose 43% in the NLR group, while and decreased by 7% the LR group on day 1. On day 7, IL-10 increased by 75% in NLR and decreased by 40% in LR, with no significance (p > 0.05).

CONCLUSION

In conclusion, leukoreduction appeared to offer some immune response protection in term of reducing mechanical ventilation timings and cytokine level changes.

Implications of perioperative allogeneic red blood cell transfusion on the immune-inflammatory response

Background

The allogeneic transfusion-related immunomodulation (TRIM) may be responsible for an increase in survival of renal transplants but in contrast it could increase the rate of bacterial infections or the recurrence rate of tumors post-operatively.

Objective

This review focuses in the implications of perioperative allogeneic transfusions on the immune-inflammatory response of surgical transfused patients.

Results

ABTs modify immune functions in recipients including decrease of the number of lymphocytes; decrease the CD4 cells; decrease the CD4/CD8 T-cell ratio; decrease NK cells; and decrease the lymphocyte response to mitogens. TRIM effects may be mediated by allogeneic white cells present in blood products; soluble peptides present in transfused plasma; and/or biologic mediators released into the supernatant of blood units. A recent systematic review and meta-analysis including 36 clinical observational studies (n = 174,036) concluded that perioperative ABTs not only decreased overall survival and reduced colorectal cancer-specific survival. Furthermore ABTs increased the rate of infectious, cardiac, pulmonary and anastomotic complications in colorectal cancer patients undergoing surgery.

Conclusions

It has been demonstrated by laboratory tests that TRIM is associated with transfusion recipient immune alterations but its influence in colorectal cancer recurrence after resection remains controversial though may exist. Surgical techniques reducing intraoperative blood loss have limited the number of ABTs perioperatively, however increase in mortality continues to be reported in literature after ABT in colorectal cancer surgery. Poor survival associated to TRIM in colorectal cancer might be due to higher number of allogeneic transfused units and/or prolonged length of blood storage.

Relationship between Inflammatory Response and Estimated Complication Rate after Total Hip Arthroplasty

BACKGROUND

After total hip arthroplasty (THA), there is a noteworthy inflammatory response. The inflammatory response is associated with postoperative recovery and complications. However, there had been few reports on the relationship between inflammatory response and postoperative complication rate. The aim of the present study was to investigate early inflammatory response in the first 3 days after THA, and to identify the relationship between inflammatory response and estimated complication rate after surgery.

METHODS

It was a prospective, nonrandomized cohort study. There were 148 patients who underwent unilateral THA in our hospital enrolled. Blood samples were collected preoperatively in the morning of the surgery and at 24, 48, and 72 h after surgery. C-reactive protein (CRP) and interleukin-6 (IL-6) in peripheral blood were measured. The modified physiological and operative severity score for the enumeration of the morbidity (POSSUM) was recorded pre- and intra-operatively. Based on the score, estimated complication rate was calculated. Harris score was used to assess hip function before and after surgery.

RESULTS

IL-6 levels reached the peak at 24 h after surgery and CRP at 48 h. After that, both of the levels decreased. The mean Harris scores significantly increased from 41.62 ± 23.47 before surgery to 72.75 ± 9.13 at 3 days after surgery. The Harris scores after surgery did not have a significant relation with either IL-6 or CRP peak levels (P = 0.165, P = 0.341, respectively). Both CRP and IL-6 peak levels significantly and positively correlated with estimated complication rate after surgery. The estimated complication rate calculated using the POSSUM system was 43 cases of 148 patients. Actually, there were only 28 cases that were observed to get postoperative complications during hospitalization. However, there was no significant difference between estimated and observed complication rates (P = 0.078). In the group with complications, the CRP and IL-6 peak levels were significantly higher than those in the group without complications (both P< 0.001).

CONCLUSIONS

There were significantly positive relationships between both peak levels of CRP and IL-6 and estimated complication rate after THA. Inflammatory response could predict the incidence of complications after THA.

The impact of two different transfusion strategies on patient immune response during major abdominal surgery: a preliminary report

Blood transfusion is associated with well-known risks. We investigated the difference between a restrictive versus a liberal transfusion strategy on the immune response, as expressed by the production of inflammatory mediators, in patients subjected to major abdominal surgery procedures. Fifty-eight patients undergoing major abdominal surgery were randomized preoperatively to either a restrictive transfusion protocol or a liberal transfusion protocol (with transfusion if hemoglobin dropped below 7.7 g dL(-1) or 9.9 g dL(-1), respectively). In a subgroup of 20 patients randomly selected from the original allocation groups, blood was sampled for measurement of IL-6, IL-10, and TNFα. Postoperative levels of IL-10 were higher in the liberal transfusion group on the first postoperative day (49.82 ± 29.07 vs. 15.83 ± 13.22 pg mL(-1), P < 0.05). Peak postoperative IL-10 levels correlated with the units of blood transfused as well as the mean duration of storage and the storage time of the oldest unit transfused (r(2) = 0.38, P = 0.032, r(2) = 0.52, P = 0.007, and r(2) = 0.68, P<0.001, respectively). IL-10 levels were elevated in patients with a more liberal red blood cell transfusion strategy. The strength of the association between anti-inflammatory IL-10 and transfusion variables indicates that IL-10 may be an important factor in transfusion-associated immunomodulation. This trial is registered under ClinicalTrials.gov Identifier: NCT02020525.

Inflammatory response to orthopedic biomaterials after total hip replacement

BACKGROUND

The aim of the present study was to investigate early inflammatory response in the first 3 days after the implantation of hip prostheses, and to compare the early inflammation responses associated with the use of different combinations of bearing materials.

METHODS

34 patients were enrolled, all of whom underwent unilateral total hip replacement and had identical hip prostheses, except for the bearing materials. These consisted of polyethylene on alumina (n = 8), polyethylene on CoCr (n = 11), or alumina on alumina (n = 15). Blood samples were collected preoperatively in the morning of the day of surgery, and at 6 h, 1 day, 2 days, and 3 days postoperatively. CK, CRP, and IL-6 in peripheral blood were measured. Pain score was obtained at 2 days after surgery.

RESULTS

There were no significant differences in the pre- and postoperative background variables among the groups. Pain scores of different groups were not significantly different either (P > 0.05). There were also no significant differences in the levels of CK, CRP, and IL-6 when patients with the three combinations of bearing materials were compared.

CONCLUSIONS

We concluded that varying the bearing materials used in the hip prosthesis did not influence the early inflammatory response after prosthesis implantation.

The age of transfused blood predicts hematocrit response among critically ill surgical patients

BACKGROUND

In vitro data suggest that erythrocytes undergo storage time-dependent degradation, eventuating in hemolysis. We hypothesize that transfusion of old blood, as compared with newer blood, results in a smaller increment in hematocrit.

METHODS

We performed an analysis of packed red blood cell transfusions administered in the surgical intensive care unit. Age of blood was analyzed as continuous, dichotomized at 14 days (old vs new), and grouped by weeks old.

RESULTS

A total of 136 U of packed red blood cells were given to 52 patients; 110 (80.9%) were 14 days old or more. A linear, inverse correlation was observed between the age of blood and the increment in hematocrit (r(2) = -.18, P = .04). The increment in hematocrit was greater after transfusion of new as compared with old blood (5.6% vs 3.5%, respectively; P = .005). A linear relationship also was observed between the age of transfused blood in weeks and the increment in hematocrit (P = .02).

CONCLUSIONS

There is an inverse relationship between the age of blood and the increment in hematocrit. The age of blood should be considered before transfusion of surgical patients with intensive care unit anemia.

Transfusion-associated immunomodulation: Quantitative changes in cytokines as a measure of immune responsiveness after one time blood transfusion in neurosurgery patients

Very few studies in humans have investigated the laboratory evidences suggestive of transfusion-associated immunologic changes. In this prospective study, we examined the effects of perioperative blood transfusion on immune response, by measuring various cytokines production, namely, interferon-gamma (IFN-γ), interleukin-10 (IL-10), and Fas Ligand (FasL). A total of 40 patients undergoing neurosurgery were randomly allocated into four groups: (a) no transfusion, (b) allogeneic non-leukofiltered transfusion, (c) prestorage leukofiltered transfusion, (d) autologous transfusion. Samples were collected before operation (day 0) and postoperative days (post-op) 1, 7, and 14. IFN-γ and IL-10 production capacity was measured in supernatant after whole blood culture and serum FasL levels in patients’ sera using commercially available ELISA kits. Change in ratios (cytokine value after PHA stimulation/control value) of IFN-γ and IL-10 and percentage change from baseline for serum FasL levels across different transfusion groups during the sampling period were calculated. There was an increase in IL-10 production in patients receiving allogeneic non-leukofiltered transfusion on days 1 and 7 (mean ratio 2.22 (± 2.16), 4.12 (± 1.71), 4.46 (± 1.97) on days 0, 1, and 7, respectively). Similarly there was a significant (P<0.05) decrease in IFN-γ production in patients who received allogeneic non-leukofiltered red cell transfusion on post-op days 1, 7, and 14 (mean ratio 6.88 (± 4.56), 2.53 (± 0.95), 3.04 (± 1.38) and 2.58 (± 1.48) on day 0, 1, 7, and 14, respectively). Serum FasL production was increased across all patients till 7th day except for ‘no transfusion’ group and this increase was most significant in the non-leukofiltered group. We conclude that one time transfusion leads to quantitative changes in levels of these cytokines largely through interplay of Th2/Th1 pathways in allogeneic nonleukofiltered blood transfusion; however, soluble mediators like FasL which are also present in autologous and leukofiltered blood products may contribute toward minor immunologic effect in these settings.

Intravenous delivery of the plasma fraction of stored packed erythrocytes promotes pancreatic cancer growth in immunocompetent mice

BACKGROUND

Perioperative blood transfusion in pancreatic cancer patients has been linked to decreased survival; however, a causal mechanism has not been determined. During the processing and storage of packed erythrocytes, biologically active molecules accumulated in the acellular plasma fraction; therefore, the authors hypothesized that the plasma fraction of stored packed erythrocytes promoted tumor progression.

METHODS

Proliferation and migration of murine pancreatic cancer and control cells were determined in vitro in response to the plasma fraction from leukocyte and nonleukocyte-reduced fresh versus stored packed erythrocytes. Last, an immunocompetent murine model was used to assess the effect of the plasma fraction of stored and processed packed erythrocytes on pancreatic cancer progression.

RESULTS

Incubation of pancreatic cancer cells with the plasma fraction of packed erythrocytes increased proliferation and migration. Intravenous delivery of the acellular plasma fraction to mice with pancreatic cancer significantly increased the tumor weight in both leukocyte-reduced and nonleukocyte-reduced packed-erythrocyte groups (P<.01), although tumor growth and morbidity were greatest in the nonleukocyte-reduced group.

CONCLUSIONS

The plasma fraction of stored packed erythrocytes promoted murine pancreatic cancer proliferation and migration in vitro and when administered intravenously, significantly augmented pancreatic cancer growth in immunocompetent mice.

Use of leukoreduced blood does not reduce infection, organ failure, or mortality following trauma

Background

Leukoreduced (LR) blood has been demonstrated to reduce morbidity and mortality in high-risk surgical patients, but not in trauma patients. The objective of the present study was to determine the effect of LR blood on morbidity and mortality. We hypothesized that the use of LR blood does not improve outcome in trauma patients.

Methods

This study was a retrospective cohort analysis of trauma patients transfused at a level 1 Trauma Center from 2001 to 2004. Between 2002 and 2003, LR blood was transfused. Prior to that time and subsequent to it, non-leukoreduced (NLR) blood was transfused. This created two historical comparison groups. Data collected included patient demographics, units of blood transfused, intensive care unit (ICU) and hospital days, ventilator days, injury severity score (ISS), mortality, presence of acute respiratory distress syndrome (ARDS), and infectious complications. A multiple organ dysfunction syndrome (MODS) score was calculated.

Results

The distribution of patients was as follows: 284 patients received only NLR blood, 153 received only LR blood, and 58 received at least one unit of each. The mean ISS was similar (NLR: 26, LR: 24; P > 0.1). No differences were seen between groups in units transfused (6.2 vs. 5.5), number of ICU days (8.2 vs. 9.0), number of hospital days (16.9 vs. 18.6), number of ventilator days (6.1 vs. 5.7), incidence of ARDS (8.3% vs. 8.5%), MODS score (5.5 vs. 5.9), mortality rate (15.1% vs. 15.7%), or infection rate (36% vs. 30%) (P > 0.1).

Conclusions

This study represents the largest series comparing trauma patients who received either LR or standard blood transfusions. The use of LR blood does not improve outcome in trauma patients.

Intraoperative allogeneic red blood cell transfusion in ampullary cancer outcome after curative pancreatoduodenectomy: a clinical study and meta-analysis

BACKGROUND

Allogeneic blood transfusion (ABT) containing packed red blood cells (RBCs) has a known immunosuppressive effect that may affect cancer metastases and recurrence. This study examined whether intraoperative allogeneic RBC transfusion is an independent risk factor of adverse outcome in patients with ampullary carcinoma after curative pancreatoduodenectomy.

METHODS

The clinical data of 67 patients with carcinoma of the ampulla of Vatar underwent pancreatoduodenectomy between 1999 and 2004 were analyzed, and long-term follow-up visits were made for all patients. Kaplan-Meier statistics and Cox proportional hazard methodology were used to perform univariate and multivariate analysis to identify independent risk factors for survival. For the meta-analysis, all English-language studies regarding blood transfusion from carcinoma of the ampulla of Vatar or ampullary carcinoma and prognostic factors or factors for survival from 1995 to 2007 were reviewed, and contingency tables were constructed from which a summary relative risk was calculated.

RESULTS

There were 43 patients (64.2%) who received an intraoperative ABT. The amount of intraoperative ABT ranged from 2 to 13 (mean, 4.25) units; there were 18 patients transfused at 2 units, and 25 patients transfused > or =3 units. The follow-up ranged from 2 to 90 (mean, 49) months. Forty-five patients (67.2%) died as a result of tumor progression. For patients transfused > or =3 units, median and cumulative 3-year and 5-year survivals were poorer significantly than that of patients transfused with 2 units and/or nontransfused patients (P < 0.05). After multivariate analysis, except for presence of lymph node metastasis (P = 0.023) and pancreatic invasion (P = 0.024), the intraoperative ABT > or =3 units was found to be an independent poor prognostic factor for those with ampullary cancer after curative pancreatoduodenectomy either (relative risk, 2.082; 95% confidence interval (CI), 1.048-4.135; P = 0.036). Meta-analysis of 346 patients showed the summary relative risk of an adverse outcome after intraoperative ABT in these studies was 2.55 (95% CI, 1.59-4.1).

CONCLUSIONS

The amount of intraoperative ABT is one of the important factors that adversely influenced survival in patients with ampullary cancer after curative pancreatoduodenectomy. Healing anemia preoperatively and careful dissection to minimize intraoperative bleeding as much as possible are mandatory for reducing risk of the intraoperative ABT.

Effect of perioperative allogeneic red blood cell transfusion on the immune-inflammatory response after colorectal cancer resection

Cytokines play an important role in the acute-phase response to trauma. Few studies have analyzed the effects of allogeneic blood transfusion containing packed red blood cells (RBCs) on the early postoperative immune/inflammatory response after colorectal resection for cancer This study investigated whether allogeneic RBC transfusion influences the postoperative immune/inflammatory response of patients submitted to large bowel resection due to cancer. A total of 26 patients -- 15 men and 11 women, with a median age of 56.5 years (range 24-87 years) -- were prospectively studied. Blood samples were obtained preoperatively and on the first and fourth postoperative days for C-reactive protein (CRP), interleukin-6 (IL-6), and IL-10 assays and for CD4 and CD8 lymphocyte counts. Transfused (> or =3 and <3 units), and nontransfused patients were compared. Both IL-6 and IL-10 increased postoperatively in transfused patients (p < 0.01). The serum IL-6 level was higher in patients receiving > or =3 units of RBCs (p < 0.01). CRP increased postoperatively unrelated to blood transfusion. The CD8 count decreased (p < 0.04) in transfused subjects, whereas CD4 decreased (p < 0.01) only in major-transfusion patients. Perioperative allogeneic RBC transfusion enhances the inflammatory systemic response and decreased immunity in patients submitted to colorectal resection for cancer.

Allogeneic blood transfusions explain increased mortality in women after coronary artery bypass graft surgery

BACKGROUND

Postoperative mortality is greater in women than men after coronary artery bypass graft surgery. Because allogeneic blood transfusions are more common in women and have been associated with immunomodulation, the impact of transfusion on sex differences in infection and mortality was examined.

METHODS

A cohort study was conducted using Michigan Medicare beneficiaries who had undergone coronary artery bypass graft surgery. Information was used regarding allogeneic blood transfusion, infection, and mortality within the 100-day period after surgery.

RESULTS

Blood transfusions were more common in women than in men (88.2%, 95% CI 87.1%-89.2% vs 66.7%, 95% CI 65.5%-67.9%). Patients who received transfused blood were more likely to have an infection than patients who did not (14.6%, 95% CI 13.8%-15.5% vs 4.9%, 95% CI 4.1%-5.9%). There was a dose-response relationship between the number of units of whole blood or packed red cells received and the prevalence of infection (P = .035). The unadjusted risk of mortality attributable to female sex was 13.9% (95% CI 8.1%-19.6%), but was no longer statistically significant when adjusted for blood transfusion (population attributable risk 0.6%, 95% CI -6.0% to 6.6%). Patients who received a transfusion were 5.6 times as likely to die within 100 days after surgery as those who did not receive a transfusion (95% CI 3.7-8.6).

CONCLUSION

The increased risk of mortality in women after bypass surgery may be explained by transfusion-related immunosuppression.

Post-operative unwashed shed blood transfusion does not modify the cellular immune response to surgery for total knee replacement

BACKGROUND

In patients undergoing total knee replacement (TKR), most blood loss occurs post-operatively, and the return of unwashed filtered shed blood (USB) from post-operative drainage may represent an alternative to allogeneic blood transfusion (ABT). We evaluated the impact of USB return on the cellular immune response (CIR) after TKR.

PATIENTS AND METHODS

Forty TKR patients, intended to receive post-operative USB, entered the study. Blood samples were obtained before and 6 h, 24 h, 72 h and 7 days after surgery, and from USB, after it had been passed through a 40-microm filter. Full blood cell counts, lymphocyte subsets and immunoglobulins (IgA, IgG, IgM) were measured in all samples. A set of clinical data was collected from each patient.

RESULTS

Twenty-four of the 25 patients received a mean of 1.2 USB units and did not need additional ABT (USB group). Twelve of the 15 remaining patients who received neither USB nor ABT served as a control group for the post-operative CIR study. All patients showed a post-operative decrease in T-cell and natural killer (NK) cell counts, but not B-cell counts, and there were no significant differences between the groups with regard to CIR parameters, post-operative infection or hospital stay.

CONCLUSIONS

Post-operative salvage and return of USB after TKR does not seem to increase the post-operative infection rate or hospital stay, and does not modify CIR induced by surgery. These findings add to the clinical experience that post-operative USB return, as a source of autologous blood, is safe, and questions the beneficial effect of blood washing.

Prestorage leukocyte reduction prevents the formation of microaggregates that occlude artificial capillary vessels

PURPOSE

The passage behavior of stored blood through an artificial microchannel system, as a model of capillary vessels, was examined.

MATERIALS AND METHODS

Using blood obtained from a total of 17 healthy volunteers, untreated and prestorage leukocyte reduced blood, or untreated and prestorage microfiltered (35 microm-pore size) blood were stored, and then the passage behavior through the microchannels was evaluated. Also, using blood from 16 patients stored for about 2 weeks, the effect of a leukocyte reduction filter, microfilter or mesh filter (175-210 microm-pore size) on the passage through the microchannels was examined.

RESULTS

Untreated blood passed through the microchannels immediately after blood collection, but after 1 week occlusion of the microchannels occurred. Prestorage leukocyte reduced blood, however, passed through the microchannels for up to 6 weeks. Occlusion of the microchannels occurred with both the untreated and prestorage microfiltered blood. Although filtration through a leukocyte reduction filter provided blood that can pass through the microchannels, occlusion occurred with blood filtered in other way.

CONCLUSIONS

The present results show that stored blood produces abundant microaggregates, potentially occluding capillary vessels. These microaggregates are not formed after prestorage leukocyte reduction or can be removed by use of a leukocyte reduction filter.

Effects of post-operative pain treatment using non-steroidal anti-inflammatory analgesics, opioids or epidural blockade on systemic and local immune responses in children

BACKGROUND

Many studies have been carried out on the effects of anaesthetic drugs and methods on the immune response, but pain and its relief also affect the immune response. We measured systemic immune responses in the blood circulation and local responses in the surgical wound when non-steroidal anti-inflammatory analgesics (NSAIDs), opioids or epidural blockade was used in the peri-operative treatment of pain.

METHODS

Responses were measured in 51 children, aged from 2 to 12 years and undergoing major surgery under balanced anaesthesia. Bolus doses of diclofenac intravenously (i.v.) and rectally (NSAID group), continuous i.v. infusion of oxycodone (opioid group) or continuous epidural infusion of bupivacaine + fentanyl (epidural group) were used peri-operatively for pain relief.

RESULTS

The only difference related to the analgesic method was shorter duration of post-operative leucocytosis and lower phytohaemagglutinin (PHA)-induced lymphocyte proliferative responses in peripheral blood in the opioid group than in the NSAID or epidural groups. By contrast, time-related alterations were seen overall in leucocyte and differential counts, lymphocyte and their subset counts, lymphocyte proliferative responses, and in serum cortisol, C-reactive protein, plasma interleukin-6 and group II phospholipase A2 concentrations and in the appearance of different cell types in the wound.

CONCLUSIONS

Post-operative pain treatments using diclofenac (NSAID), oxycodone (opioid) and epidural blockade have basically similar effects on systemic and local immune responses with only slight, probably clinically unimportant differences in children undergoing surgery under general anaesthesia.

Supernatant from stored red blood cell primes inflammatory cells: influence of prestorage white cell reduction

BACKGROUND

The contribution of RBC transfusion to adverse patient outcomes is controversial. There is conflicting clinical data and limited biologic data that provide an underpinning biologic rationale for any adverse impacts from RBC transfusion. This study used in-vitro measures of PMN stimulation to determine the ability of supernatant from RBCs to stimulate allogeneic WBCs and to determine the influence of residual donor WBCs and storage time on the proinflammatory potential of RBCs.

STUDY DESIGN AND METHODS

Three types of RBCs were assessed: standard non-WBC-reduced RBCs (S-RBCs), buffy coat-poor RBCs (BCP-RBCs), and prestorage WBC-filtered RBC (LF-RBCs). Supernatant was collected weekly up to Day 42 of storage. PMN priming by supernatant from RBCs was determined by three methods: induction of CD11b expression on PMNs, induction of IL-8 release from PMNs, and the chemotactic effect of supernatant on PMNs.

RESULTS

Supernatant from S-RBCs induced the expression of CD11b on PMNs, primed PMNs to release IL-8, and was chemotactic for PMNs. The magnitude of this PMN-priming progressively amplified with storage time. In contrast, supernatant from BCP-RBCs or LF-RBCs did not significantly prime PMNs. The PMN-priming effect of supernatant from RBCs correlated more closely with the level of MNCs in the RBCs than PMN content.

CONCLUSION

Supernatant from stored S-RBCs prime unstimulated allogeneic PMNs in vitro. Prestorage buffy-coat WBC reduction was as effective as WBC depletion in abrogating this proinflammatory response elicited by supernatants from RBCs. The clinical consequences, if any, of these findings for transfusion recipients are unknown.

Expression of Fas and Fas ligand on spleen T cells of experimental animals after unmodified or leukoreduced allogeneic blood transfusions

BACKGROUND

The clonal deletion seen in recipients of allogeneic blood transfusion (ABT) refers to the removal of lymphocytes that promote the clearance of transfused alloantigens. Interactions between Fas (CD95) and FasL (CD95L) are involved in the clonal deletion of T cells and in the down regulation of the cytotoxic T-cell activity.

STUDY DESIGN AND METHODS

The expression of CD95/95 L on spleen T cells of C57Bl/6 mice infused with unmodified ABT, prestorage leukoreduced ABT (LR-ABT), or saline was investigated by flow cytometry. The numbers of apoptotic spleen cells were evaluated after transfusion using the acridine orange and ethidium bromide uptake technique.

RESULTS

Compared with untransfused animals, mice transfused with ABT showed higher expression of CD95 (MFI = 94.4 +/- 8.6 vs. 73.1 +/- 7.9, p = 0.02) and CD95L (23.5 +/- 6.9 vs. 8.1 +/- 2.0, p = 0.008) on CD4+ spleen cells. Expression of CD95 (92.2 +/- 7.5 vs. 64.9 +/- 7.5, p = 0.007) and CD95L (17.7 +/- 3.6 vs. 8.2 +/- 2.2, p = 0.02) was also increased on CD8+ cells of these animals. CD8+ spleen cells from mice transfused with ABT showed higher expression of CD95 (92.2 +/- 7.5 vs. 76.9 +/- 4.0, p = 0.03) and CD95L (17.7 +/- 3.6 vs. 8.3 +/- 1.5, p = 0.03) than cells from mice transfused with LR-ABT. The number of apoptotic spleen cells from mice transfused with ABT was greater than that from mice infused with LR-ABT (10.9 +/- 1.3 vs. 6.6 +/- 1.8, p = 0.01) or saline (10.9 +/- 1.3 vs. 6.5 +/- 0.7, p = 0.001).

CONCLUSIONS

The data suggest that ABT up-regulates the expression of Fas/FasL on spleen T cells of mice and may promote their apoptosis. These ABT-associated immunologic alterations can be partially prevented by the leukoreduction of the transfused blood.

Anemia in acute renal failure: role for erythropoiesis-stimulating proteins?

The use of recombinant human erythropoietin (rHuEpo) has revolutionized anemia management of early and late stages of chronic kidney disease. Darbopoietin is also now available for the treatment of anemia of chronic kidney disease. In addition, rHuEpo has been used for the treatment of anemia observed in critical illness. Unfortunately, the existing clinical studies of anemia in critically ill patients do not distinguish between those with and without acute renal failure (ARF). This review summarizes the existing experimental and clinical studies supporting the use of rHuEpo in ARF due to ischemic/nephrotoxic injury and conclusions are drawn on the rationale for further research into the use of this drug in ARF.

Signs and symptoms associated with the transfusion of WBC-reduced RBCs and non-WBC-reduced RBCs in patients with anemia and HIV infection: results from the Viral Activation Transfusion Study

BACKGROUND

RBC transfusion is associated with fever and other reactions in some patients. The Viral Activation Transfusion Study randomly assigned patients to receive either unmodified or WBC-reduced RBCs and thus offered an opportunity to assess the effect of WBC-reduced RBCs on the incidence of transfusion reactions prospectively.

STUDY DESIGN AND METHODS

This prospective, randomized, double-blind, multicenter study compared prestorage WBC-reduced RBCs to unmodified RBCs in HIV-infected, CMV-seropositive, and transfusion-naive persons who required transfusions for anemia. Primary endpoints were survival and change in the plasma HIV RNA level at 7 days after transfusion. The incidence of transfusion reactions was prospectively evaluated.

RESULTS

The two groups had similar baseline characteristics and study endpoints; 3864 RBC units (median storage age, 9 days) were administered to 531 patients during 1745 transfusions. The most frequent signs reported were elevated temperature and hypotension. Subjects who reported fever within the week prior to transfusion were more likely to have an elevation in temperature associated with transfusion. The administration of RBCs that were less than 10 days old was associated with a marginal increase in the incidence of transfusion-associated temperature elevation among recipients of unmodified RBCs, but not among recipients of WBC-reduced RBCs. Caregivers reported fewer instances of both elevated temperature and hypotension than were identified by review of transfusion records.

CONCLUSIONS

The incidence of elevated temperature and hypotension associated with transfusion in this population was unexpectedly high. Use of WBC-reduced RBCs had no effect on the overall rates of elevated temperature or hypotension associated with transfusion of RBCs. The occurrence of a pre-existing fever was associated with a higher frequency of transfusion-associated elevated temperature.

Survival and function of baboon RBCs released from clotted blood and washed before autologous transfusion

BACKGROUND

One alternative to an allogeneic transfusion is the salvaging of the patient's own shed blood. In this study, baboon blood was allowed to clot and the RBCs that were released from the clotted blood lysed with and without urokinase were washed before autologous transfusion.

STUDY DESIGN AND METHODS

Forty-four studies were done in 13 baboons (Papio cynocephalus or Papio anubis) over a 3-year period. In 24 studies, a 50-mL volume of blood was collected without an anticoagulant and stored at 22 degrees C for as long as 72 hours before washing and autologous transfusion. In 20 other studies, a 50-mL volume of blood was collected without an anticoagulant and allowed to clot for 30 to 60 minutes. Urokinase, ranging from 2,500 to 10,000 units per mL, was added, and the blood was stored at 22 degrees C for 24 hours before washing and autologous transfusion.

RESULTS

RBCs that were stored at 22 degrees C without urokinase for 24 hours exhibited an in vitro recovery value of 45 percent, a (51)Cr 24-hour posttransfusion survival of 86 percent, and an index of therapeutic effectiveness of 39 percent. The (51)Cr T(50) value was normal at 14 days, and RBC oxygen-transport function was slightly reduced. RBCs that were stored at 22 degrees C for 24 hours with 10,000 units per mL of urokinase exhibited an in vitro recovery value of 89 percent, a (51)Cr 24-hour posttransfusion survival value of 86 percent, and an index of therapeutic effectiveness of 76 percent. The (51)Cr T(50) value was normal at 14 days, and the RBC oxygen-transport function was only slightly reduced.

CONCLUSION

Autologous baboon RBCs isolated from clotted blood treated or not treated with urokinase and washed before transfusion have excellent survival and normal or only slightly reduced oxygen-transport function.

Survival, function, and hemolysis of shed red blood cells processed as nonwashed blood and washed red blood cells

BACKGROUND

Shed nonwashed blood and shed washed red blood cells (RBC) are being used as alternatives to allogeneic liquid-preserved RBC for patients during thoracic and cardiovascular surgical procedures.

METHODS

Mongrel dogs were bled a volume of blood into the abdominal cavity and the shed blood was reinfused as nonwashed blood or washed RBC. The 51Cr RBC volumes were measured before, immediately after, and 24 hours after the exchange transfusion to assess the recovery of the shed RBC and the 24-hour posttransfusion survival. Compatible dogs were given allogeneic transfusions of 51Cr-labeled nonwashed blood and washed RBC, and 24-hour posttransfusion survival and half-life were measured.

RESULTS

Immediately after the 100% exchange transfusion, the recovery value was 62% for the nonwashed shed blood and 82% for the washed RBC. Both the nonwashed blood and the washed RBC had 24-hour posttransfusion survival values of 90% and normal oxygen transport function after the exchange transfusion. Compatible allogeneic 51Cr-labeled nonwashed blood and washed RBC had normal 24-hour posttranfusion survival and 51Cr half-life values.

CONCLUSIONS

The survival, function, and hemolysis of shed nonwashed blood and shed washed RBC were similar to fresh blood in the dog that underwent a 100% exchange transfusion.

Immune response to autologous transfusion in healthy volunteers: WB versus packed RBCs and FFP

BACKGROUND

Storage of blood as packed RBCs and FFP is standard practice in allogeneic transfusion. Separation into components has been proposed for autologous transfusion, as well, but beneficial effects have not yet been shown.

STUDY DESIGN AND METHODS

Twenty-four healthy male volunteers were randomly assigned to receive 1 unit of either autologous RBCs and FFP (RCP group) or WB (WB group) after 49 or 35 days of storage, respectively. The immune response was analyzed by ELISA for IL-6, C3a, terminal complement complex SC5b-9, TNF-alpha, and neopterin. Differential WBC counts and the phagocytosis of neutrophils and monocytes were measured by flow cytometry.

RESULTS

Cell counts of monocytes (0.85 x 10(3) ng/microL) [corrected] and neutrophils (6.9 x 10(3) ng/microL) [corrected] increased 30 minutes after WB transfusion and then returned to close to the baseline values seen in the RCP group (0.47 and 2.9 x 10(3) ng/microL [corrected], respectively) throughout the monitored period (p<0.05). C3a (169 vs. 116 ng/microL) [corrected] and IL-6 (29 vs. 6 pg/mL) reached higher plasma concentrations in the WB group (n = 11) than in the RCP group (n = 10). Phagocytosis of opsonized Escherichia coli was increased in neutrophils and monocytes and lasted up to 7 days after the transfusion of whole blood.

CONCLUSION

Autologous WB induces a modest immunomodulation, but this effect is not observed upon transfusion of autologous blood components.

Release of WBC-derived IL-1 receptor antagonist into supernatants of RBCs: influence of storage time and filtration

BACKGROUND

Transfusion-associated immunodepression may be related to the transfer of immunoinhibitory cytokines with blood components.

STUDY DESIGN AND METHODS

After evidence of increasing concentrations of IL-1 receptor antagonist (IL-1RA) but not of IL-10 was obtained in supernatants of stored RBC units that were WBC-reduced by centrifugation (C-RBCs) in a pilot study, IL-1RA concentrations were determined weekly in supernatants of C-RBCs and in units that underwent prestorage WBC reduction by in-line filtration (F-RBCs) over a 49-day storage. For assessing total IL-1RA content, complete cell lysis by repeated freezing and thawing was done. The results were related to the changes in WBC count during storage. The dependency of IL-1RA content on preparation procedures was assessed.

RESULTS

The prestorage IL-1RA concentration in C-RBCs (859 +/- 218 pg/mL) was significantly higher than in F-RBC (75 +/- 13 pg/mL). Whereas no changes were seen in F-RBCs during storage, IL-1RA levels in C-RBC supernatants drastically increased to levels about 50 times those in normal plasma (16,327 +/- 2,686 pg/mL on Day 49). Follow-up analysis revealed stringent correlation between IL-1RA release into supernatants and the current loss of WBCs (r = 0.79, n = 42; p<0.001). The total IL-1RA content did not change during storage and was directly dependent on prestorage WBC count. Preparation procedures altered the IL-1RA content only by WBC reduction.

CONCLUSION

The immunosuppressive cytokine IL-1RA is transmitted by RBCs in relation to WBC content and storage time.

Leucocyte depletion of blood components

Universal leucocyte depletion has been implemented in the UK and several other European countries as a precautionary measure against the potential risk of transmission of variant Creutzfeldt-Jakob disease by blood transfusion. Leucocyte depletion had previously only been recommended for a relatively small proportion of transfusion recipients based on clinical and experimental evidence showing clinical benefit. However there is now increasing evidence to support its value in preventing transfusion transmission of infectious agents and in reducing some of the adverse immunomodulatory effects of allogeneic transfusion. The financial costs of providing universal leucocyte depletion are substantial, but, if it transpires that leucocyte depletion has a beneficial effect in reducing, for example, postoperative infection rates, then the health economic gains in this patient group alone may largely or wholly offset these financial costs. The experience in the UK and other European countries in terms of these collateral clinical benefits will help other countries, where the risk of variant Creutzfeldt-Jakob disease may not be so great, to decide whether to similarly adopt universal leucocyte depletion.