Transfusion-related immunomodulation (TRIM): an update

Cytomegalovirus infection in severe burn patients monitoring by real-time polymerase chain reaction: A prospective study

BACKGROUND

Cytomegalovirus (CMV) infection has been shown to occur not rarely in critically ill patients in the past decade. However, little data are available on CMV infection in burn patients whereas their susceptibility to CMV infection has been proved.

METHODS

We prospectively assessed CMV viremia by real-time polymerase chain reaction and clinical outcome in immunocompetent burn patients with total burn surface area greater than 15%.

RESULTS

Twenty-nine patients were enrolled. The rate of CMV infection was of 71% in CMV seropositive burn patients, and of 12.5% in CMV seronegative burn patients. CMV reactivation was associated with a higher IGS 2 score on admission. High grade CMV viremia was associated with longer mechanical ventilation duration, higher infection number, higher transfused red blood cell number, and longer ICU stays. There were no differences on mortality rate between patients with and without CMV reactivation.

CONCLUSION

CMV infection rate is considerable in burn patients with TBSA greater than 15%. This infection seems to be mostly due to reactivation of latently existing virus.

Phase II comparison study of intraoperative autotransfusion for major oncologic procedures

BACKGROUND

Intraoperative autotransfusion (IOAT) has been avoided in oncologic surgery because of possible tumor cell dissemination. Through a prior Phase I study, we demonstrated that malignant cells are not present in blood filtered for IOAT. We hypothesized that autotransfusion could be safely used for patients undergoing major oncologic procedures and reduce the need for allogeneic blood.

MATERIALS AND METHODS

A Phase II, IRB-approved, prospective evaluation was conducted of patients undergoing gastrointestinal oncologic procedures. All procedures were conducted with blood salvaged for IOAT, and the collected volume was autotransfused if it was >100 ml. Quality of life (QoL) was assessed by questionnaire at regular intervals.

RESULTS

A total of 92 patients were enrolled with median age of 56 years. The most commonly performed procedures were hepatectomy (47%) and pancreaticoduodenectomy (26%). The median preoperative hemoglobin (Hgb) was 13.1 (range, 9-16), and the median estimated blood loss was 350 ml (range, 20-4000 ml). Of the 92 total patients, 32 (35%) received IOAT with a median volume of 255 ml (range, 117-1499 ml). Multivariate analysis identified that patients with preoperative Hgb >11 g/dl (P = .02), and blood loss of 400-900 ml (P = .03) benefited from IOAT with a reduction in postoperative blood transfusion rate. Patients with discharge Hgb >10 g/dl showed higher mean QoL scores throughout their recovery. At a median follow-up of 18 months, the rates of recurrence in the IOAT and the non-IOAT groups were equivalent (38 vs. 39%, P = .9).

CONCLUSIONS

Intraoperative autotransfusion can be used safely and effectively for major oncologic procedures. Furthermore, degree of discharge anemia is associated with lower quality of life in patients undergoing oncologic gastrointestinal surgery.

Down regulation of human natural killer cell-mediated cytolysis induced by blood transfusion: role of transforming growth factor-β(1), soluble Fas ligand, and soluble Class I human leukocyte antigen

BACKGROUND

Human natural killer (NK) cells are thought to play a role in antiviral response and tumor immune surveillance. The molecular mechanisms of down regulation of NK-cell activity observed after red blood cell (RBC) transfusion is still undefined.

STUDY DESIGN AND METHODS

Both effects of blood transfusion (ex vivo) and supernatants (SNs) derived from RBC units unstored (RBC-0) or stored for 5 or 30 days (RBC-5 or -30, respectively) in vitro were analyzed on NK cell-mediated cytolytic activity.

RESULTS

We have found that NK cells isolated from transfused patients on Day 3 lysed the NK-sensitive target cells K562 to a lesser extent than before transfusion. This down regulation of NK-cell activation was evident also for NK-cell killing mediated through the engagement of NK cell-activating receptors as NKG2D, NKp30, NKp46, and CD16. Transfused patients reacquired NK cell-mediated cytolytic activity from Day 5 to Day 7 after transfusion. SN from RBC-30, but not from RBC-0 or RBC-5, strongly inhibited the generation of lymphokine-activated killer (LAK) cells and lysis of the NK-resistant target cell Jurkat in a dose-dependent manner. Transforming growth factor-β1 (TGF-β1) blocking antibodies partially restored the generation of LAK activity. In addition, the depletion of both soluble Class I human leukocyte antigens (sHLA-I) and soluble Fas ligand (sFasL) from SN of RBC-30 completely restored the generation of LAK activity.

CONCLUSIONS

Altogether, these findings would support the idea that blood transfusion-mediated down regulation of NK-cell activity is mediated by sHLA-I, sFasL, and TGF-β1.

Differential effect of pretransplant blood transfusions on immune effector and regulatory compartments in HLA-sensitized and nonsensitized recipients

BACKGROUND

Blood transfusion (BT) may elicit both harmful and beneficial immune responses against a subsequent organ graft. Immune parameters of a single, non leukocyte-depleted BT were investigated in two groups: non-human leukocyte antigen (HLA)-sensitized recipients with a one-HLA-DR matched donor (protocolled BT [PBT]) and females with previous exposure to HLA alloantigens through pregnancy (donor-specific transfusion [DST]).

METHODS

Thirty-five percent of DST recipients and 9.5% of PBT recipients developed HLA antibodies after BT.Phenotypic and functional analyses were performed in pre-BT, 2 weeks post-BT, and more than 10 weeks post-BT samples (PBT: n=10; DST: n=14).

RESULT

The number of donor-reactive interferon-γ-producing memory T cells increased 2 weeks post-BT, but only in the DST group, increased frequencies persisted beyond 10 weeks (P0.004). In the DST recipients, the proportion of natural killer cells (CD3(-)CD56(+)) significantly increased after BT (P=0.01), whereas in PBT recipients, the proportion of regulatoryT cells (CD4(+)CD25(+)Foxp3(+)CD127 low) significantly increased at 2 weeks post-BT (P=0.039). Microarray analysis confirmed increased activity of genes involved in function of natural killer cells,Tcells, and Bcells in DSTrecipients and increased expression of immune regulatory genes (galectin-1, Foxo3a, and follistatin-like 3) in PBT recipients. Galectin-1 expression by quantitative polymerase chain reaction was significantly enhanced in peripheral blood cells after PBT (P0.05).

CONCLUSION

Decreased immune effector mechanisms combined with an increased immune regulatory cell signature after HLA-DR-matched BT in nonsensitized patients is in line with clinical observations of improved outcome of a subsequent graft. Previous sensitization, however, may lead to HLA antibody formation and prolonged donor-specific memory T-cell reactivity after BT.

Inactivation of human white blood cells in platelet products after pathogen reduction technology treatment in comparison to gamma irradiation

BACKGROUND

During the transfusion of blood products, the transfer of allogeneic donor white blood cells (WBCs) can mediate adverse reactions in recipients. To minimize reactions, blood components are leukoreduced and/or exposed to gamma irradiation. Nucleic acid-targeted pathogen reduction technologies (PRTs) processes are well suited for WBC inactivation. The Mirasol PRT system (CaridianBCT Biotechnologies) uses riboflavin and ultraviolet light to reduce the active pathogen load and inactivate residual WBCs in blood products used for transfusion. The aim of this study was to compare the effect of PRT treatment to gamma irradiation.

MATERIALS AND METHODS

WBCs were resuspended in 100% plasma or in plasma containing 65% platelet additive solution (SSP+). A single product was split into three aliquots: control, PRT treatment, or gamma irradiation. After treatment, peripheral blood mononuclear cells were isolated from products, and cell viability and functionality were assessed in limiting dilution assays (LDAs), by CD69 expression, by proliferation, and by cytokine accumulation after lipopolysaccharide addition.

RESULTS

PRT treatment and gamma irradiation reduced the ability of the T cells to proliferate by similar degrees as evidenced by a 6 log or greater reduction in the LDA and a lack of response to several stimuli. However, gamma-irradiated T cells were still capable of up regulating surface CD69, inducing a proliferative response in allogeneic responder cells, and producing levels of proinflammatory cytokines similar to those of untreated control cells, responses that PRT-treated T cells were incapable of mediating.

CONCLUSIONS

These in vitro results demonstrate that PRT treatment is more effective than gamma irradiation at abrogating selected WBC immune functions.

Controversies related to red blood cell transfusion in critically ill patients

OBJECTIVE

To review the evolution of and controversies associated with allogenic blood transfusion in critically ill patients.

DATA SOURCES

Veterinary and human literature review.

HUMAN DATA SYNTHESIS

RBC transfusion practices for ICU patients have come under scrutiny in the last 2 decades. Human trials have demonstrated relative tolerance to severe, euvolemic anemia and a significant outcome advantage following implementation of more restricted transfusion therapy. Investigators question the ability of RBCs stored longer than 2 weeks to improve tissue oxygenation, and theorize that both age and proinflammatory or immunomodulating effects of transfused cells may limit efficacy and contribute to increased patient morbidity and mortality. Also controversial is the ability of pre- and post-storage leukoreduction of RBCs to mitigate adverse transfusion-related events.

VETERINARY DATA SYNTHESIS

While there are several studies evaluating the transfusion trigger, the RBC storage lesion and transfusion-related immunomodulation in experimental animal models, there is little research pertaining to clinical veterinary patients.

CONCLUSIONS

RBC transfusion is unequivocally indicated for treatment of anemic hypoxia. However, critical hemoglobin or Hct below which all critically ill patients require transfusion has not been established and there are inherent risks associated with allogenic blood transfusion. Clinical trials designed to evaluate the effects of RBC age and leukoreduction on veterinary patient outcome are warranted. Implementation of evidence-based transfusion guidelines and consideration of alternatives to allogenic blood transfusion are advisable.

Blood transfusions and the subsequent risk of hematologic malignancies

BACKGROUND

Blood transfusions are associated with viral transmission and immunomodulation, perhaps increasing subsequent risk of hematologic malignancies (HMs). Prior studies of transfusion recipients have lacked details on specific HM subtypes.

STUDY DESIGN AND METHODS

Risk of HM after blood transfusion was evaluated in a US population-based case-control study (77,488 elderly HM cases identified through cancer registries, 154,509 controls). Transfusions were identified using linked Medicare hospitalization claims. Polytomous logistic regression was used to calculate odds ratios (ORs) associating transfusion and HM subtypes by features suggestive of a causal relationship.

RESULTS

A history of transfusion was present in 7.9% of HM cases versus 5.9% of controls. Associations for most HM subtypes suggested reverse causality: ORs were elevated only during the shortest latency periods; ORs for unspecified anemia and gastrointestinal bleeding, which may be related to undiagnosed HM, were stronger than for surgeries, which are unlikely to be related to HM; and/or there was no dose response. In contrast, risk for lymphoplasmacytic lymphoma (1397 cases) was elevated at long latency (OR, 1.56 at 10+ years after transfusion), after transfusions related to surgeries (OR, 1.22-1.47), and in a dose-response relationship with number of transfusion-related hospitalizations (OR, 1.53 with one hospitalization; OR, 1.80 with two or more hospitalizations, p trend < 0.0001). Risk for marginal zone lymphoma (1915 cases) was also elevated at 10+ years after transfusion (OR, 1.80).

CONCLUSION

Consistent with prior studies, blood transfusions did not increase risk of most HM subtypes. Patterns of elevated risk for lymphoplasmacytic and marginal zone lymphomas suggest an etiologic role for transfusion.

Gender-specific transfusion affects tumor-associated neutrophil: macrophage ratios in murine pancreatic adenocarcinoma

INTRODUCTION

Perioperative blood transfusion has been linked to decreased survival for pancreas cancer. Noting clinical data associating female blood products with increased morbidity, our lab has demonstrated that transfusion of female blood augments metastatic events compared to male blood in an immunocompetent murine pancreatic cancer model. It has been suggested that tumor-associated macrophages correlate with tumor progression by promoting angiogenesis. More recently, tumor-associated neutrophils have been implicated in aggressive tumor behavior. We hypothesize that differences in gender-specific transfusion-mediated pancreatic cancer progression are due to microenvironmental changes within the tumor. To test this hypothesis, we examined tumor-associated neutrophils and macrophage ratios in male and female mice with pancreatic cancer receiving blood transfusion from male or female donors.

METHODS

C57/BL6 mice, age 7-9 weeks, underwent splenic inoculation with 2.5 × 10(5) PanO2 murine pancreatic adenocarcinoma cells. Mice were transfused on post-op day 7 with 1 ml/kg supernatant from day 42 male or female packed red cells. Necropsy was performed at 5 weeks or earlier for clinical deterioration, and tumors harvested. Frozen sections (5 µm) were stained for neutrophils and macrophages by immunofluorescence. Data were analyzed using ANOVA; p ≤ 0.05 was used to determine significance; N ≥ 3 per group.

RESULTS

Clinically, male mice had greater morbidity and mortality than female mice when receiving female blood products, with roughened hair coat, development of ascites and death due to bowel obstruction. In evaluating the tumor microenvironment from mice receiving female blood products, male mice were noted to have a greater neutrophil to macrophage ratio than female mice, 0.176 ± 0.028 vs. 0.073 ± 0.012, p = 0.03. When examining neutrophil to macrophage ratio in mice receiving male blood products, no difference was noted (p = 0.48).

CONCLUSIONS

Male mice with pancreas cancer have greater morbidity than female mice when receiving female blood products. Furthermore, the difference in neutrophil to macrophage ratio suggests that gender-specific blood transfusion promotes aggressive tumor behavior in male mice via microenvironmental changes. These data warrant further study to delineate sex-related differences in pancreatic cancer progression.

Packed red blood cells suppress T-cell proliferation through a process involving cell-cell contact

BACKGROUND

Packed red blood cell (PRBC) transfusion suppresses immunity and increases morbidity and mortality. Leukocyte reduction has failed to abrogate these effects, thus implicating red blood cells themselves or their components. PRBC impair proliferation of immortal (Jurkat) T cells by depleting arginine from the extracellular environment. The effect of PRBC on isolated ex vivo T-cell proliferation has not been reported. We hypothesize that PRBCs depress mitogen-stimulated proliferation in isolated human and mouse T cells.

METHODS

Human peripheral T cells were isolated by Ficoll-Hypaque gradient, purified by magnetic separation, and stimulated with anti-CD3 or anti-CD28. DO11.10 transgenic mouse splenic T cells were stimulated with ovalbumin. Cells were cultured at 1 x 10(6)/mL in 96-well plates or in 24-transwell plates in the presence of PRBC (0.015-5% by volume, stored for 4-6 weeks). In culture media, arginine and citrulline were varied. Proliferation was measured at 72 hours by thymidine incorporation. T-cell viability, apoptosis, and receptor zeta chain were measured by flow cytometry.

RESULTS

PRBC significantly depressed human peripheral and mouse splenic T-cell proliferation in a dose-dependent manner. PRBC arginase blockade by N-omega-hydroxy-nor-l-arginine only partly restored proliferation. Cell contact was required in both cell types for maximal effect. Depressed zeta chain in human peripheral T cells was partly restored by arginase blockade. Salvage by high-dose arginine and citrulline was unsuccessful. Decreased proliferation was not related to cell death.

CONCLUSION

PRBC suppresses mitogen-stimulated human and antigen-stimulated mouse T-cell proliferation by mechanisms independent of arginine depletion. This is a novel mechanism for transfusion-associated immune suppression.

The optimal hematocrit

Nearly 15 million units of packed red blood cells and whole blood are transfused annually in the United States alone. Until recently, the major risks from blood transfusion were thought to be transmission of viral infections, and overall, blood transfusion was believed by most providers to be safe. A safe hemoglobin threshold above which red cell transfusion is clearly unnecessary has not been established. This article addresses the numerous problems that surround the use and consequences of blood transfusion, such as hemoglobin and hematocrit levels, oxygenation, storage time, immunomodulation, infection, and anemia. The relevant literature is comprehensively reviewed.

Are red blood cell transfusions associated with nosocomial infections in pediatric intensive care units?

OBJECTIVES

To determine whether red blood cell transfusion is similarly associated with nosocomial infections in pediatric intensive care unit patients and whether reduced lymphocyte numbers is a possible mechanism. In adult studies, red blood cell transfusions are associated with nosocomial infections.

DESIGN

Historical cohort study.

SETTING

Single-center, mixed medical-surgical, closed pediatric intensive care unit of a tertiary university-affiliated children's hospital.

PATIENTS

All patients < or = 18 yrs old admitted to the pediatric intensive care unit during a 6-month period from January 1 to July 3, 2005.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Nosocomial infections (respiratory, urinary tract, and bloodstream infections) were the primary outcome measure and were defined as post transfusion if occurring within 14 days after red blood cell transfusion. Of the 209 subjects enrolled, 32 (15%) acquired nosocomial infections and 45 (22%) received red blood cell transfusions. Patients with versus without nosocomial infections had received red blood cell transfusions significantly more often (odds ratio, 18.0; 95% confidence interval, 7.6-45.9; p < .001). In a dose-dependence analysis, we found that patients receiving > or = 3 red blood cell transfusions had a similar prevalence of nosocomial infections compared with those receiving one to two red blood cell transfusions (61% vs. 44%, p = .365), but greater mortality (22% vs. 0%, p = .04). In a multiple logistic regression analysis controlling for gender, age, pediatric intensive care unit length of stay, presence of an invasive catheter, mechanical ventilation, and surgery, red blood cell transfusion remained independently associated with risk of nosocomial infection (odds ratio, 3.73; 95% confidence interval, 1.19-11.85, p = .023). Transfused subjects had lower absolute lymphocyte counts compared with nontransfused subjects (1605 vs. 2054/microL, p = .041), but similar total white blood cell counts (10.4 vs. 11.4 x 10/microL, p = .52).

CONCLUSION

Red blood cell transfusion in pediatric intensive care unit patients is associated with an increased risk of nosocomial infections.

Perioperative blood transfusions promote pancreas cancer progression

Complex abdominal procedures to extirpate malignancies are often associated with blood transfusion. In particular, perioperative transfusion rates for pancreaticoduodenectomy can be as high as 75%. In the early 1970s it was shown that blood transfusions likely had immunomodulating effects as renal allografts were found to have longer survival in patients who received multiple transfusions. Subsequently, it has been suggested that blood transfusions may promote cancer progression. Many retrospective series have supported this hypothesis, and recent studies examining long-term survival in patients undergoing "Whipple" procedures suggests that transfusion is a negative prognostic factor. Despite these studies, the claim that transfusion is a simple surrogate for patient health, tumor size, location, and biology are difficult to refute. The use of syngeneic murine models has allowed many confounding variables to be controlled, and suggest that transfusion does indeed promote pancreas cancer progression. Based on these findings, as well as the continued need for blood transfusion, alternate strategies in transfusion management are warranted.

The plasma fraction of stored erythrocytes augments pancreatic cancer metastasis in male versus female mice

BACKGROUND

Males with pancreatic cancer have decreased survival compared with females. Interestingly, perioperative blood transfusions have been shown to reduce survival in patients with pancreatic adenocarcinoma. Recent evidence incriminates blood transfusions from female donors as a causative factor in acute lung injury. We therefore hypothesize that male mice with pancreatic cancer will have greater tumor progression than female mice in response to transfusion.

METHODS

Mice previously inoculated with pancreatic cancer cells received an intravenous injection of acellular plasma collected from single donor erythrocytes from either male or female donors. Control mice received an equal volume of intravenous saline. Necropsy to determine metastasis was performed in female mice at 4 wk status post-transfusion. The male group necessitated sacrifice at 3 wk post-transfusion due to clinical deterioration.

RESULTS

Male mice developed more metastatic events than female mice, and this was accentuated when receiving blood from female donors. Male mice experienced weight loss within 2 wk of tail vein injection, and three mice in the male transfused groups died secondary to malignancy. Female mice did not manifest substantial weight loss, and did not die in the study time period.

CONCLUSION

Male mice, compared with female, had significantly more metastatic events following transfusion of plasma from stored erythrocytes in an immunocompetent murine model of pancreatic adenocarcinoma. Moreover, the adverse effect of transfusion was augmented with female donor blood. These data are consistent with clinical outcomes from centers of excellence in treating pancreatic cancer and warrant further investigation.

Anemia and blood transfusion and outcome on the intensive care unit

The observation of Sakr and colleagues that transfusion may be beneficial in certain subgroups of intensive care unit (ICU) patients [1] is interesting, since large observational studies demonstrate that transfusion is independently associated with an increased risk of death [2]. Also, a systematic review showed that the benefits of transfusion in the ICU do not outweigh the risks [3]. Sakr and colleagues ascribe their discrepant results to the fact that transfused blood was leukoreduced. Of the 17 randomized controlled trials on the association of nonleukoreduced blood with mortality, however, a benefit of leukoreduction was found only in cardiac surgery patients [4]. A meta-analysis confirmed that available evidence does not justify universal leukoreduction [5].

Given the increased risk of nosocomial infection, multiple organ failure and acute respiratory distress syndrome, an explanation of a beneficial effect from transfusion in anemic critically ill patients is tempting. We propose that the results of this study may be related to the indication of transfusion, this being active bleeding and not correction of anemia associated with critical illness. Hereby, transfusion may have prevented adverse events due to postoperative bleeding, explaining the survival benefit. The fact that 76% of patients were referred from the operating/recovery room and that the median length of ICU stay was only 1 day may support this hypothesis. Based on numerous reports on the association of transfusion with adverse outcome, a liberal transfusion strategy in critically ill anemic patients in the absence of acute bleeding should not be advocated.

Anemia and blood transfusion in a surgical intensive care unit

INTRODUCTION

Studies in intensive care unit (ICU) patients have suggested that anemia and blood transfusions can influence outcomes, but these effects have not been widely investigated specifically in surgical ICU patients.

METHODS

We retrospectively analyzed the prospectively collected data from all adult patients (>18 years old) admitted to a 50-bed surgical ICU between 1st March 2004 and 30th July 2006.

RESULTS

Of the 5925 patients admitted during the study period, 1833 (30.9%) received a blood transfusion in the ICU. Hemoglobin concentrations were < 9 g/dl on at least one occasion in 57.6% of patients. Lower hemoglobin concentrations were associated with a higher Simplified Acute Physiology Score II and Sequential Organ Failure Assessment score, greater mortality rates, and longer ICU and hospital lengths of stay. Transfused patients had higher ICU (12.5 vs. 3.2%) and hospital (18.3 vs. 6.5%) mortality rates (both p < 0.001) than non-transfused patients. However, ICU and in-hospital mortality rates were similar among transfused and non-transfused matched pairs according to a propensity score (n = 1184 pairs), and after adjustment for possible confounders in a multivariable analysis, higher hemoglobin concentrations (RR 0.97[0.95-0.98], per 1 g/dl, p < 0.001) and blood transfusions (RR 0.96[0.92-0.99], p = 0.031) were independently associated with a lower risk of in-hospital death, especially in patients aged from 66 to 80 years, in patients admitted to the ICU after non-cardiovascular surgery, in patients with higher severity scores, and in patients with severe sepsis.

CONCLUSIONS

In this group of surgical ICU patients, anemia was common and was associated with higher morbidity and mortality. Higher hemoglobin concentrations and receipt of a blood transfusion were independently associated with a lower risk of in-hospital death. Randomized control studies are warranted to confirm the potential benefit of blood transfusions in these subpopulations.

Blood product replacement for postpartum hemorrhage

Hemorrhage requiring blood transfusion is a common occurrence in obstetrics. This article reviews each step in the transfusion process, including laboratory preparation of blood, indications for various blood components, complications of blood transfusion, massive transfusion, and alternatives to homologous blood. Current thinking regarding transfusion-related acute lung injury, transfusion-related immunomodulation, early use of plasma for massive transfusion, and the use of adjuvant agents such as activated recombinant factor VII are also discussed.

Predictors of extrahepatic recurrence after curative hepatectomy for hepatocellular carcinoma

BACKGROUND

The aim of this study was to elucidate the predictors of extrahepatic hepatocellular carcinoma (HCC) recurrence after hepatectomy.

MATERIALS AND METHODS

A cohort of 252 patients with HCC who underwent hepatectomy following a recurrence were reviewed. The patients were categorized into 2 groups according to the pattern of their initial recurrence. Clinicopathological and survival data were compared between the groups.

RESULTS

Of the 252 patients, 218 had intrahepatic recurrence (IHR) (86.5%) and 34 had extrahepatic recurrence (EHR) (13.5%) as their initial recurrence. The mean duration of time until the initial recurrence after hepatectomy of the EHR and IHR groups was 1.8 and 2.2 years, respectively. The rate of recurrence within 6 months after hepatectomy of EHR and IHR groups was 35.3 and 14.2%, respectively (P = .002). The 3-, 5-, and 10-year cumulative survival rates of EHR group were 60.3, 24.0, and 6.0%, respectively, which were significantly lower than that of IHR group (74.5, 57.7, and 23.1%, P = .004). A multivariate analysis showed that blood loss during surgery and microscopic hepatic vein invasion remained as independent risk factors for increased EHR after hepatectomy for HCC. Furthermore, the combination of these 2 independent factors showed a significant association with the EHR.

CONCLUSIONS

EHR of HCC was associated with early recurrence and a poor survival after a hepatectomy. The combination of 2 independent factors for EHR, the presence of microscopic hepatic vein invasion and the blood loss during surgery, may be useful for predicting the risk for occurrence of EHR during the follow-up period.

Association between length of storage of red blood cell units and outcome of critically ill children: a prospective observational study

INTRODUCTION

Transfusion is a common treatment in pediatric intensive care units (PICUs). Studies in adults suggest that prolonged storage of red blood cell units is associated with worse clinical outcome. No prospective study has been conducted in children. Our objectives were to assess the clinical impact of the length of storage of red blood cell units on clinical outcome of critically ill children.

METHODS

Prospective, observational study conducted in 30 North American centers, in consecutive patients aged <18 years with a stay >or= 48 hours in a PICU. The primary outcome measure was the incidence of multiple organ dysfunction syndrome after transfusion. The secondary outcomes were 28-day mortality and PICU length of stay. Odds ratios were adjusted for gender, age, number of organ dysfunctions at admission, total number of transfusions, and total dose of transfusion, using a multiple logistic regression model.

RESULTS

The median length of storage was 14 days in 296 patients with documented length of storage. For patients receiving blood stored >or= 14 days, the adjusted odds ratio for an increased incidence of multiple organ dysfunction syndrome was 1.87 (95% CI 1.04;3.27, P = 0.03). There was also a significant difference in the total PICU length of stay (adjusted median difference +3.7 days, P < 0.001) and no significant change in mortality.

CONCLUSIONS

In critically ill children, transfusion of red blood cell units stored for >or= 14 days is independently associated with an increased occurrence of multiple organ dysfunction syndrome and prolonged PICU stay.

Association between length of storage of red blood cell units and outcome of critically ill children: a prospective observational study

INTRODUCTION

Transfusion is a common treatment in pediatric intensive care units (PICUs). Studies in adults suggest that prolonged storage of red blood cell units is associated with worse clinical outcome. No prospective study has been conducted in children. Our objectives were to assess the clinical impact of the length of storage of red blood cell units on clinical outcome of critically ill children.

METHODS

Prospective, observational study conducted in 30 North American centers, in consecutive patients aged <18 years with a stay >or= 48 hours in a PICU. The primary outcome measure was the incidence of multiple organ dysfunction syndrome after transfusion. The secondary outcomes were 28-day mortality and PICU length of stay. Odds ratios were adjusted for gender, age, number of organ dysfunctions at admission, total number of transfusions, and total dose of transfusion, using a multiple logistic regression model.

RESULTS

The median length of storage was 14 days in 296 patients with documented length of storage. For patients receiving blood stored >or= 14 days, the adjusted odds ratio for an increased incidence of multiple organ dysfunction syndrome was 1.87 (95% CI 1.04;3.27, P = 0.03). There was also a significant difference in the total PICU length of stay (adjusted median difference +3.7 days, P < 0.001) and no significant change in mortality.

CONCLUSIONS

In critically ill children, transfusion of red blood cell units stored for >or= 14 days is independently associated with an increased occurrence of multiple organ dysfunction syndrome and prolonged PICU stay.

Blood still kills: six strategies to further reduce allogeneic blood transfusion-related mortality

After reviewing the relative frequency of the causes of allogeneic blood transfusion-related mortality in the United States today, we present 6 possible strategies for further reducing such transfusion-related mortality. These are (1) avoidance of unnecessary transfusions through the use of evidence-based transfusion guidelines, to reduce potentially fatal (infectious as well as noninfectious) transfusion complications; (2) reduction in the risk of transfusion-related acute lung injury in recipients of platelet transfusions through the use of single-donor platelets collected from male donors, or female donors without a history of pregnancy or who have been shown not to have white blood cell (WBC) antibodies; (3) prevention of hemolytic transfusion reactions through the augmentation of patient identification procedures by the addition of information technologies, as well as through the prevention of additional red blood cell alloantibody formation in patients who are likely to need multiple transfusions in the future; (4) avoidance of pooled blood products (such as pooled whole blood-derived platelets) to reduce the risk of transmission of emerging transfusion-transmitted infections (TTIs) and the residual risk from known TTIs (especially transfusion-associated sepsis [TAS]); (5) WBC reduction of cellular blood components administered in cardiac surgery to prevent the poorly understood increased mortality seen in cardiac surgery patients in association with the receipt of non-WBC-reduced (compared with WBC-reduced) transfusion; and (6) pathogen reduction of platelet and plasma components to prevent the transfusion transmission of most emerging, potentially fatal TTIs and the residual risk of known TTIs (especially TAS).

Red blood cell transfusion threshold in postsurgical pediatric intensive care patients: a randomized clinical trial

BACKGROUND

The optimal transfusion threshold after surgery in children is unknown. We analyzed the general surgery subgroup of the TRIPICU (Transfusion Requirements in Pediatric Intensive Care Units) study to determine the impact of a restrictive versus a liberal transfusion strategy on new or progressive multiple organ dysfunction syndrome (MODS).

METHODS

The TRIPICU study, a prospective randomized controlled trial conducted in 17 centers, enrolled a total of 648 critically ill children with a hemoglobin equal to or below 9.5 g/dL within 7 days of pediatric intensive care unit (PICU) admission to receive prestorage leukocyte-reduced red-cell transfusion if their hemoglobin dropped below either 7.0 g/dL (restrictive) or 9.5 g/dL (liberal). A subgroup of 124 postoperative patients (60 randomized to restrictive and 64 to the liberal group) were analyzed. This study was registered at http://www.controlled-trials.com and carries the following ID ISRCTN37246456.

RESULTS

Participants in the restrictive and liberal groups were similar at randomization in age (restrictive vs. liberal: 53.5 +/- 51.8 vs. 73.7 +/- 61.8 months), severity of illness (pediatric risk of mortality [PRISM] score: 3.5 +/- 4.0 vs. 4.4 +/- 4.0), MODS (35% vs. 29%), need for mechanical ventilation (77% vs. 74%), and hemoglobin level (7.7 +/- 1.1 vs. 7.9 +/- 1.0 g/dL). The mean hemoglobin level remained 2.3 g/dL lower in the restrictive group after randomization. No significant differences were found for new or progressive MODS (8% vs. 9%; P = 0.83) or for 28-day mortality (2% vs. 2%; P = 0.96) in the restrictive versus liberal group. However, there was a statistically significant difference between groups for PICU length of stay (7.7 +/- 6.6 days for the restrictive group vs. 11.6 +/- 10.2 days for the liberal group; P = 0.03).

CONCLUSIONS

In this subgroup analysis of pediatric general surgery patients, we found no conclusive evidence that a restrictive red-cell transfusion strategy, as compared with a liberal one, increased the rate of new or progressive MODS or mortality.

Differential effects of propofol and isoflurane on the activation of T-helper cells in lung cancer patients

It is suggested that activation and differentiation of T-helper cells are required for peri-operative anti-tumor and anti-infection immunity. The present study aimed to evaluate whether propofol stimulates the activation and differentiation of these cells in patients undergoing pulmonary lobectomy for non-small-cell lung cancer. Thirty patients were randomly allocated to receive propofol or isoflurane throughout surgery. The CD4(+)CD28(+) percentage (p < 0.0001) and the ratio of interferon-gamma:interleukin-4 (p = 0.001) all increased with propofol but showed no change with isoflurane. In contrast, cortisol increased with isoflurane (p < 0.0001) but not with propofol over time (p = 0.06). We conclude that propofol promotes activation and differentiation of peripheral T-helper cells.

Convalescent transfusion for pandemic influenza: preparing blood banks for a new plasma product?

Due to the potential of a severe pandemic to limit efficacy or availability of medical countermeasures, some researchers have begun a search for new interventions that could complement the planned antiviral‐ and vaccine‐based response to an influenza pandemic. One such countermeasure—the transfusion of pandemic influenza‐specific antibodies from surviving patients to the clinically ill—is the focus of this commentary. Passive immunotherapy, which includes the use of monoclonal antibodies (MoAbs), hyperimmune globulin, or convalescent plasma, had been used before the advent of antibiotics and has recently reentered the limelight due to the accelerating development of MoAb therapies against cancer, a number of microbes, allograft rejection, and a host of other conditions. After the plausible biologic mechanism and somewhat limited data supporting the efficacy for this modality against influenza are reviewed, safety and logistical concerns for utilization of this potential new product (fresh convalescent plasma against influenza [FCP‐Flu]) are discussed. FCP‐Flu could indeed prove useful in a response to a pandemic, but two necessary items must first be satisfied. Most importantly, more research should be conducted to establish FCP‐Flu efficacy against the current and other pandemic strains. Second, and also importantly, blood banks and donor centers should examine whether offering this new product would be feasible in a pandemic and begin planning before a more severe pandemic forces us to respond without adequate preparation.

Why implement universal leukoreduction?

The improvement of transfusion medicine technology is an ongoing process primarily directed at increasing the safety of allogeneic blood component transfusions for recipients. Over the years, relatively little attention had been paid to the leukocytes present in the various blood components. The availability of leukocyte removal (leukoreduction) techniques for blood components is associated with a considerable improvement in various clinical outcomes. These include a reduction in the frequency and severity of febrile transfusion reactions, reduced cytomegalovirus transfusion-transmission risk, the reduced incidence of alloimmune platelet refractoriness, a possible reduction in the risk of transfusion-associated variant Creutzfeldt-Jakob disease transmission, as well as reducing the overall risk of both recipient mortality and organ dysfunction, particularly in cardiac surgery patients and possibly in other categories of patients. Internationally, 19 countries have implemented universal leukocyte reduction (ULR) as part of their blood safety policy. The main reason for not implementing ULR in those countries that have not appears to be primarily concerns over costs. Nonetheless, the available international experience supports the concept that ULR is a process that results in improved safety of allogeneic blood components.

Blood transfusion is associated with increased morbidity and mortality after lower extremity revascularization

BACKGROUND

Little is known about the significance of blood transfusion in patients with peripheral arterial disease. We queried the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database to examine the effect of intraoperative blood transfusion on the morbidity and mortality in patients who underwent lower extremity revascularization.

METHODS

We analyzed data from the participant use data file containing vascular surgical cases submitted to the ACS NSQIP in 2005, 2006, and 2007 by 173 hospitals. Current procedural terminology codes were used to select lower extremity procedures that were grouped into venous graft, prosthetic graft, or thromboendarterectomy. Thirty-day outcomes analyzed were (1) mortality, (2) composite morbidity, (3) graft/prosthesis failure, (4) return to the operating room within 30 days, (5) wound occurrences, (6) sepsis or septic shock, (7) pulmonary occurrences, and (8) renal insufficiency or failure. Intraoperative transfusion of packed red blood cells was categorized as none, 1 to 2 units, and 3 or more units. Outcome rates were compared between the transfused and nontransfused groups using the chi(2) test and multivariable regression adjusting for transfusion propensity, comorbid and procedural risk.

RESULTS

A total of 8799 patients underwent lower extremity revascularization between 2005 and 2007. Mean age was 66.8 +/- 12.0 years and 5569 (63.3%) were male. Transfusion rates ranged from 14.5% in thromboendarterectomy patients to 27.1% in prosthetic bypass patients (P < .05). After adjustment for transfusion propensity and patient and procedural risks, transfusion of 1 or 2 units remained significantly predictive of mortality, composite morbidity, sepsis/shock, pulmonary occurrences, and return to the operating room. The adjusted odds ratios for 30-day mortality ranged from 1.92 (95% confidence interval [CI] 1.36-2.70) for 1 to 2 units to 2.48 (95% CI 1.55-3.98) for 3 or more units.

CONCLUSION

In a large number of patients undergoing lower extremity revascularization, we have found that there is a higher risk of postoperative mortality, pulmonary, and infectious complications after receiving intraoperative blood transfusion. Additional studies are necessary to better define transfusion triggers that balance the risk/benefit ratio for blood transfusion.

Developing a risk stratification model for surgical site infection after abdominal hysterectomy

OBJECTIVE

The incidence of surgical site infection (SSI) after hysterectomy ranges widely from 2% to 21%. A specific risk stratification index could help to predict more accurately the risk of incisional SSI following abdominal hysterectomy and would help determine the reasons for the wide range of reported SSI rates in individual studies. To increase our understanding of the risk factors needed to build a specific risk stratification index, we performed a retrospective multihospital analysis of risk factors for SSI after abdominal hysterectomy.

METHODS

Retrospective case-control study of 545 abdominal and 275 vaginal hysterectomies from July 1, 2003, to June 30, 2005, at 4 institutions. SSIs were defined by using Centers for Disease Control and Prevention/National Nosocomial Infections Surveillance criteria. Independent risk factors for abdominal hysterectomy were identified by using logistic regression.

RESULTS

There were 13 deep incisional, 53 superficial incisional, and 18 organ-space SSIs after abdominal hysterectomy and 14 organ-space SSIs after vaginal hysterectomy. Because risk factors for organ-space SSI were different according to univariate analysis, we focused further analyses on incisional SSI after abdominal hysterectomy. The maximum serum glucose level within 5 days after operation was highest in patients with deep incisional SSI, lower in patients with superficial incisional SSI, and lowest in uninfected patients (median, 189, 156, and 141 mg/dL, respectively; P = .005). Independent risk factors for incisional SSI included blood transfusion (odds ratio [OR], 2.4) and morbid obesity (body mass index [BMI], >35; OR, 5.7). Duration of operation greater than the 75th percentile (OR, 1.7), obesity (BMI, 30-35; OR, 3.0), and lack of private health insurance (OR, 1.7) were marginally associated with increased odds of SSI.

CONCLUSIONS

Incisional SSI after abdominal hysterectomy was associated with increased BMI and blood transfusion. Longer duration of operation and lack of private health insurance were marginally associated with SSI.

Infections in thalassemia and hemoglobinopathies: focus on therapy-related complications

The clinical approach to thalassemia and hemoglobinopathies, specifically Sickle Cell Disease (SCD), based on transfusions, iron chelation and bone marrow transplantation has ameliorated their prognosis. Nevertheless, infections still may cause serious complications in these patients. The susceptibility to infections in thalassemia and SCD arises both from a large spectrum of immunological abnormalities and from exposure to specific infectious agents. Four fundamental issues will be focused upon as central causes of immune dysfunction: the diseases themselves; iron overload, transfusion therapy and the role of the spleen. Thalassemia and SCD differ in their pathogenesis and clinical course. It will be outlined how these differences affect immune dysfunction, the risk of infections and the types of most frequent infections in each disease. Moreover, since transfusions are a fundamental tool for treating these patients, their safety is paramount in reducing the risks of infections. In recent years, careful surveillance worldwide and improvements in laboratory tests reduced greatly transfusion transmitted infections, but the problem is not completely resolved. Finally, selected topics will be discussed regarding Parvovirus B19 and transfusion transmitted infections as well as the prevention of infectious risk postsplenectomy or in presence of functional asplenia.

Effects of transfusions in extremely low birth weight infants: a retrospective study

OBJECTIVES

To determine the risks and benefits associated with the transfusion of packed red blood cells (PRBCs) in extremely low birth weight (ELBW) infants. We hypothesized that when ELBW infants underwent transfusion with the University of Washington Neonatal Intensive Care Unit (NICU) 2006 guidelines, no clinical benefit would be discernible.

STUDY DESIGN

We conducted a retrospective chart review of all ELBW infants admitted to the NICU in 2006. Information on weight gain, apnea, heart rate, and respiratory support was collected for 2 days preceding, the day of, and 3 days after PRBC transfusion. The incidence, timing, and severity of complications of prematurity were documented.

RESULTS

Of the 60 ELBW infants admitted to the NICU in 2006, 78% received PRBC transfusions. Transfusions were not associated with improved weight gain, apnea, or ventilatory/oxygen needs. However, they were associated with increased risk of bronchopulmonary dysplasia, necrotizing enterocolitis, and diuretic use (P < .05). Transfusions correlated with phlebotomy losses, gestational age, and birth weight. No association was found between transfusions and sepsis, retinopathy of prematurity, or erythropoietin use.

CONCLUSIONS

When our 2006 PRBC transfusion guidelines were used, no identifiable clinical benefits were identified, but increased complications of prematurity were noted. New, more restrictive guidelines were developed as a result of this study.

Effects of transfusions in extremely low birth weight infants: a retrospective study

OBJECTIVES

To determine the risks and benefits associated with the transfusion of packed red blood cells (PRBCs) in extremely low birth weight (ELBW) infants. We hypothesized that when ELBW infants underwent transfusion with the University of Washington Neonatal Intensive Care Unit (NICU) 2006 guidelines, no clinical benefit would be discernible.

STUDY DESIGN

We conducted a retrospective chart review of all ELBW infants admitted to the NICU in 2006. Information on weight gain, apnea, heart rate, and respiratory support was collected for 2 days preceding, the day of, and 3 days after PRBC transfusion. The incidence, timing, and severity of complications of prematurity were documented.

RESULTS

Of the 60 ELBW infants admitted to the NICU in 2006, 78% received PRBC transfusions. Transfusions were not associated with improved weight gain, apnea, or ventilatory/oxygen needs. However, they were associated with increased risk of bronchopulmonary dysplasia, necrotizing enterocolitis, and diuretic use (P < .05). Transfusions correlated with phlebotomy losses, gestational age, and birth weight. No association was found between transfusions and sepsis, retinopathy of prematurity, or erythropoietin use.

CONCLUSIONS

When our 2006 PRBC transfusion guidelines were used, no identifiable clinical benefits were identified, but increased complications of prematurity were noted. New, more restrictive guidelines were developed as a result of this study.

Leucocyte depletion of perioperative blood transfusion does not affect long-term survival and recurrence in patients with gastrointestinal cancer

BACKGROUND

Perioperative red blood cell (RBC) transfusion may be associated with a poor prognosis in cancer surgery. Allogeneic leucocytes are assumed to play a causal role. This study evaluated the long-term effect of transfusion with leucocyte-depleted (LD) blood in patients with gastrointestinal cancer.

METHODS

The Transfusion Associated Complications = Transfusion Induced Complications? (TACTIC) study is a multicentre randomized controlled trial evaluating the short-term benefits of LD versus non-LD RBC transfusions. The present study evaluated 5-year survival and cancer recurrence among 512 patients with gastrointestinal cancer included in the TACTIC study.

RESULTS

Some 89.2 per cent of patients had a primary tumour and 79.7 per cent underwent surgery with curative intent; 243 patients received perioperative RBC transfusion (median 3 units). The 5-year overall survival rate of patients with any type of gastrointestinal cancer was 50.8 per cent in the LD group and 45.8 per cent in the non-LD group (P = 0.191). Corresponding 5-year disease-free survival rates were 60.0 and 56.6 per cent (P = 0.482), and recurrence rates 32.9 and 34.3 per cent (P = 0.864).

CONCLUSION

Leucocyte depletion is not associated with better long-term survival and lower recurrence rates in patients with gastrointestinal cancer.

Liver donor's age and recipient's serum creatinine predict blood component use during liver transplantation

BACKGROUND

Excessive use of blood components during liver transplantation should be avoided because it has been associated with poor outcomes and it may stress blood bank resources.

STUDY DESIGN AND METHODS

To determine preoperative predictors of excessive transfusion requirements in patients undergoing liver transplantation, the clinical records of 126 consecutive adult patients undergoing primary liver transplantation were retrospectively reviewed. Outcome variables included number of red blood cells (RBCs), plasma, and plateletpheresis components intraoperatively transfused. Univariate analyses of the following predictor variables were performed: recipient age, sex, ethnicity, height/weight, Model for End Stage Liver Disease score, year of transplant, previous abdominal surgery, hepatoma, wait-list time, standard recipient laboratory values obtained immediately before transplantation, cold ischemia time, donor age, sex, and height/weight. Multivariate analysis using logistic regression was used to build a model that best predicted how many blood components should be available before transplant.

RESULTS

Donor age of more than 50 years old (odds ratio [OR], 2.8 95% confidence interval [CI], 1.3-6.0), and recipient serum creatinine (SCr) level of more than 1.3 mg/dL (OR, 3.8 95% CI, 1.6-8.9) were the only variables found to be predictive of RBC use in multivariate analysis. This model accurately predicted the use of more than 10 units of RBCs 79% of cases. Having both adverse factors present resulted in using more than one box in 80% of cases as compared to 44% of cases where only one or no adverse factor was present (p = 0.002). Further analyses showed a direct correlation between the number of RBCs transfused and plasma (r = 0.93) and plateletpheresis components (r = 0.74) transfused. [Corrections added after online publication 22-Jul-2009: OR updated from 3.8 to 2.8; CI from 1.6-8.9 to 1.3-6.0; OR from 2.8-3.8.]

CONCLUSION

Liver donor's age and recipient's SCr are important in preoperatively predicting blood use during liver transplantation.

Length of storage and in vitro immunomodulation induced by prestorage leukoreduced red blood cells

BACKGROUND

The relationship between length of storage of red blood cell (RBC) units and biochemical changes has been well studied, but little is known about the progression of cellular immunomodulative properties in blood recipients. This study aims to quantify in vitro T-cell activation and cytokine release by white blood cells, after incubation with supernatants from leukoreduced RBCs.

STUDY DESIGN AND METHODS

Whole blood cultures were incubated with supernatant from five leukoreduced RBC units stored for 1, 6, 10, 15, 24, and 42 days. Supernatant-induced T-cell activation was evaluated by quantifying CD25 expression. Supernatant-induced cytokine production was determined by measuring interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha levels.

RESULTS

No cytokines were detected in RBC supernatants even after 42 days of storage. However, IL-6 levels in whole blood culture increased significantly when incubated with supernatant from RBC units stored for 1, 6, and 15 days, by factors of 1.7 +/- 0.3, 1.7 +/- 0.3, and 1.4 +/- 0.3, respectively. TNF-alpha levels were significantly decreased on Days 24 and 42 of storage by factors of 0.50 +/- 0.42 and 0.33 +/- 0.21, respectively. IL-10 levels were significantly increased on Days 1 and 42 of storage by factors of 2.3 +/- 1.3 and 3.2 +/- 2.8, respectively. After an initial increase in IL-6 and TNF-alpha production, there was a significant linear decrease in their levels measured from units stored for longer times. No significant changes in CD25 expression were observed over time.

CONCLUSION

Although no cytokines were measured in the supernatants from leukoreduced RBCs, these supernatants exhibited variable immunomodulatory effects related to their length of storage.

Anaesthetic considerations of the HIV-infected patients

PURPOSE OF REVIEW

Human immunodeficiency virus (HIV) infection is one of the major global health problems. Because the advances in treatment of HIV infection increase the patient's survival, anaesthesiologists may care for these patients during their practice. This article highlights HIV infection and anaesthetic implications.

RECENT FINDINGS

HIV infection is a spectrum of disease varying from asymptomatic to multiple organ involvement. Safe anaesthetic management in HIV-infected patients includes understanding basic knowledge of HIV infection, organ involvement, pharmacology and adverse reactions of antiretroviral agents. There are no specific anaesthetic agents and techniques for HIV-infected patients. Issues on central neural blockade and immunological aspects on HIV infection were discussed. Infection control to prevent transmission of infections to and from HIV-infected patients must be strictly conducted.

SUMMARY

Anaesthesia in HIV-infected patients should be individualized and depend on the status of the patient.

Bleeding, blood transfusion, and increased mortality after percutaneous coronary intervention: implications for contemporary practice

Advances in percutaneous coronary intervention (PCI) during the past decade have led to more widespread use of these procedures in older and sicker patients. Refinement of periprocedural antithrombotic therapy has played a particularly important role in reducing ischemic complications to very low levels in routine practice. Although the use of more powerful antiplatelet agents has been associated with increased risk of bleeding (especially among the elderly and patients with serious comorbidities), such complications have traditionally been viewed as benign in nature. Recent studies, however, have identified major bleeding after PCI as an important predictor of increased mortality. Whether this relationship between bleeding and risk of death is cause-and-effect, or merely an association based on shared risk factors, remains unclear. In this review, we examine the basis for a possible causal link between post-PCI bleeding and subsequent mortality. Possible mechanisms underpinning such a link are discussed, including a potential adverse role for blood transfusion in this setting. A framework for further clinical evaluation of this issue is presented.

Cytomegalovirus infection in critically ill patients: a systematic review

INTRODUCTION

The precise role of cytomegalovirus (CMV) infection in contributing to outcomes in critically ill immunocompetent patients has not been fully defined.

METHODS

Studies in which critically ill immunocompetent adults were monitored for CMV infection in the intensive care unit (ICU) were reviewed.

RESULTS

CMV infection occurs in 0 to 36% of critically ill patients, mostly between 4 and 12 days after ICU admission. Potential risk factors for CMV infection include sepsis, requirement of mechanical ventilation, and transfusions. Prolonged mechanical ventilation (21 to 39 days vs. 13 to 24 days) and duration of ICU stay (33 to 69 days vs. 22 to 48 days) correlated significantly with a higher risk of CMV infection. Mortality rates in patients with CMV infection were higher in some but not all studies. Whether CMV produces febrile syndrome or end-organ disease directly in these patients is not known.

CONCLUSIONS

CMV infection frequently occurs in critically ill immunocompetent patients and may be associated with poor outcomes. Further studies are warranted to identify subsets of patients who are likely to develop CMV infection and to determine the impact of antiviral agents on clinically meaningful outcomes in these patients.

Influence of red blood cell transfusion on CD4+ T-helper cells immune response in patients undergoing cardiac surgery

BACKGROUND

Both surgical insult and red blood cell transfusion (RBCT) induce alterations in type-1/type-2, CD4T-helper cell balance. This study was aimed to determine the influence of RBCT on Th1 and Th2 function immune response in cardiac surgery patients.

MATERIAL AND METHODS

Three blood samples were prospectively drawn from 81 cardiac surgery patients with cardiopulmonary bypass (CPB): preoperatively (preOP), during CPB, before RBCT (intraOP), and on postoperative day 1 (postOP). Immune response was assessed by flow cytometry measurement of the proportion of CD4(+)T-helper cells producing tumor necrosis factor (TNF)-α [Th1 response] and interleukin (IL)-10 [Th2 response].

RESULTS

Sixty-two patients were transfused (3.4 ± 2.3 units/patient), whereas 19 did not. Both groups were homogeneous, both at baseline and during surgery, regarding multiple perioperative clinical and laboratory variables, but postoperative blood loss and transfused RBC units were significantly higher in transfused versus nontransfused patients. In contrast, preoperative hemoglobin was significantly higher in nontransfused patients. CD4(+)T-helper cells significantly decreased in both groups of patients from preOP to intraOP 1 and from intraOP to postOP. In nontransfused patients, there were no significant changes in CD4(+)T-helper cells expressing TNFα or IL-10 among different sampling times. In contrast, RBCT resulted in a significant increment in Th2 response from intraOP to postOP (P=0.01), without affecting Th1 response.

CONCLUSION

RBCT, but not surgery or CPB, induces a shift of the Th1/Th2 balance toward Th2 dominance.