Factors affecting growth of Yersinia enterocolitica in cellular blood products

Overnight, room temperature hold of whole blood followed by 42-day storage of red blood cells in additive solution-7

BACKGROUND

Overnight, room temperature hold (ONH) of whole blood before component processing offers several benefits. This study evaluated the storage and in vivo recovery characteristics of ONH red blood cells (RBCs) stored in additive solution-7 (AS-7).

STUDY DESIGN AND METHODS

We conducted a three-center, three-arm evaluation of a new blood collection system with AS-7 compared to leukoreduced RBCs processed within 8 hours and stored in AS-1 (control). Whole blood (500 ± 50 mL) from healthy research subjects (n = 240) was held at room temperature 0 to 2 hours, 6 to 8 hours, or ONH (18-24 hr) before component processing and storage at 1 to 6 °C. RBCs were evaluated on Days 42 and 56 with a panel of in vitro assays. Subsets of the AS-7-stored RBCs were evaluated for (51) Cr 24-hour in vivo recovery and long-term survival.

RESULTS

Adenosine triphosphate (ATP) levels in ONH RBCs were not different than AS-7 RBCs prepared within 8 hours. ATP was higher in the ONH group on Day 42 than control, and ATP was maintained in all AS-7 groups through Day 56. ONH units had 0.36 ± 0.14% on Day 42 hemolysis (60/60 < 0.8%), and 0.54 ± 0.22% on Day 56 (10/60 > 0.8%, 2/60 > 1%). In vivo recoveries of stored RBCs were not different between the AS-7 arms at 42 days (p = 0.16; 27/27 ONH units > 75%), but the Day 56 ONH was significantly less than ONH on Day 42 (p = 0.008; 7/28 < 75%).

CONCLUSIONS

Overnight hold of whole blood at room temperature before component processing meets current regulatory requirements when RBCs are stored up to 42 days in AS-7.

Extracellular accumulation of bioactive substances; Interleukin-1β (IL-1β) and plasminogen activator inhibitor-1 (PAI-1) in stored blood units and relation to bacterial contamination

Bacterial contamination of blood and its cellular components remains an unresolved problem in transfusion medicine and is considered to be the most common microbiological cause of transfusion associated morbidity and mortality. The present work was designed to explore the levels of two bioactive compounds interleukin-1 beta (IL-1beta) and plasminogen activator inhibitor-1 (PAI-1) in stored blood units and their relation to bacterial contamination of these units. This study was conducted on 112 blood units obtained from blood bank of Mansoura University Children Hospital. Sequential blood samples were obtained both immediately at donation and after 10 days for measurement of IL-1beta and PAI-1 and for bacterial culture by BACTEC 9050 system. There was statistically significant increase in both IL-1 beta and PAI-1 (P = 0.0001) after 10 days of blood units storage. Bacteriological culture revealed no growth in 68% and positive growth in 32% of blood units. The commonest isolated organism was Staphylococcus aureus (15%) followed by Staphylococcus epidermedis (13%) then Yersinia sp. and Enterobacter sp. (2%) for each. From the present study we could conclude that stored blood units contain platelets and WBCs derived bioactive substances PAI-1 and IL-1beta which increase with the duration of blood storage. Furthermore, the extended duration of storage carries the danger of blood contamination by bacteria. Automated blood culture system seems to be helpful in identification of bacterial contamination of blood units. We recommend fresh blood transfusion as early as possible and the practice of Leucofiltration to avoid blood transfusion complications.

Effect of Safety Measures on Bacterial Contamination Rates of Blood Components in Germany

SUMMARY: Requirements for bacterial testing of blood components on a defined quantity as part of routine quality control were introduced in Germany by the National Advisory Committee Blood of the German Federal Ministry of Health in 1997. The philosophy was to establish standardized methods for bacterial testing. Numerous measures to reduce the risk of bacterial contamination were implemented into the blood donation and manufacturing processes between 1999 and 2002. German Blood establishments performed culture-based bacterial testing on random samples of platelet concentrates (PCs), red blood cells (RBCs) and fresh frozen plasma (FFP) and reported data out of the production periods 1998, 2001 and 2005/2006. While the bacterial contamination rate of apheresis PCs remained nearly unchanged, it decreased by 70% for pooled PCs to a rate of 0.158% in the last observation period. Leukocyte-depleted RBCs with diversion of the initial blood volume showed a contamination rate of 0.029% which is significantly lower than that of RBCs without leukocyte depletion and diversion (0.157%). The contamination rate of plasma decreased by 80%. Preventive measures resulted in a significant reduction of bacterial contamination of blood components. Long-term monitoring with standardized methods for bacteria testing supports evaluation of the cumulative effect of contamination reducing measures.

Ambient overnight hold of whole blood prior to the manufacture of blood components

Blood services routinely separate whole blood into components that are then stored under different conditions. The storage conditions used for whole blood prior to separation must therefore be a compromise between the needs of the red cells (which benefit from refrigeration) and plasma and platelets (which are better preserved at ambient temperature). For many years, the approach has been to manufacture plasma and platelet components on the day of blood collection, and to refrigerate any unprocessed blood for manufacture into red cell components on the following day. However, this can make it challenging to maintain adequate stocks of all components. The European practice of 'ambient hold' of whole blood for up to 24 hours prior to processing allows greater flexibility in blood component manufacture, and the data reviewed suggest there is relatively little impact on the quality of red cell or plasma components, and an improvement in the quality of platelet components.

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).

Meta-analysis of clinical studies of the purported deleterious effects of "old" (versus "fresh") red blood cells: are we at equipoise?

BACKGROUND

A meta-analysis examined whether the available data support an adequate suspicion that transfusion of old red blood cells (RBCs) is associated with increased mortality, organ failure, infection, prolonged mechanical ventilation, and prolonged stay in the hospital or the intensive care unit. Such suspicion is required for intentionally exposing patients enrolled in randomized controlled trials (RCTs) to the known or probable--but rare--risks of old RBCs, to document (and prevent) purported common adverse effects of old RBCs.

STUDY DESIGN AND METHODS

Observational studies presenting adjusted results were eligible for analysis if the adequacy of the adjustment for confounding factors could be assessed. Three RCTs and 24 observational studies were retrieved. Medically and statistically homogeneous studies were integrated by fixed-effects methods. Otherwise homogeneous studies conducted in different clinical settings were integrated by random-effects methods.

RESULTS

Based on "as-treated" analysis, transfusion of old RBCs was associated with a significant reduction in mortality (summary odds ratio, 0.38; 95% confidence interval, 0.14-0.99; p < 0.05) across two small RCTs. Integration of adjusted findings on the same outcome, from observational studies conducted in the same setting, produced summary results that were either negative (in six analyses) or impossible to evaluate owing to uncontrolled confounding by the number of transfused RBCs (in two analyses).

CONCLUSION

The available data do not support an adequate suspicion that old RBCs may be associated with common adverse morbidity and/or mortality outcomes, so as to justify exposing experimental subjects to the other known or probable--but rare--risks of old RBCs.

Prevention of Yersinia enterocolitica, Pseudomonas fluorescens, and Pseudomonas putida outgrowth in deliberately inoculated blood by a novel pathogen-reduction process

BACKGROUND

Yersinia enterocolitica, Pseudomonas fluorescens, and P. putida are responsible for a significant amount of the bacterial sepsis cases attributed to RBC transfusions. INACTINE is a pathogen-reduction process for RBCs, which consists of incubation of RBCs with PEN110 (proprietary compound) followed by automated washing of the RBCs. INACTINE is an electrophilic agent, which inactivates a wide range of viruses and WBCs by disruption of nucleic acid replication. The present study investigated the effect of the PEN110 process on Y. enterocolitica, P. fluorescens, and P. putida.

STUDY DESIGN AND METHODS

Identical units of reduced CPD/ADSOL additive solution (AS-1) or CP2D/Nutricel additive solution (AS-3) RBCs were inoculated with 10 to 100 CFU per mL of either Y. enterocolitica, P. fluorescens, or P. putida. The control units were put on storage immediately after the bacterial spike. The test units were subjected to the PEN110 process and then stored. Sham control units were processed the same way as test units without addition of PEN110. Bacterial titer in all units was monitored during the 6-week storage period.

RESULTS

No bacteria were detected in any of the RBC units (n = 9 for each microorganism) prepared using the PEN110 process throughout 6 weeks of storage. Substantial bacterial growth occurred in all control and in a majority of sham control units (11 out of 15 experiments). The bacterial inactivation by the INACTINE process was found to be equally effective in CPD/AS-1 and CP2D/AS-3 RBC units.

CONCLUSION

The INACTINE process effectively prevented the outgrowth of Y. enterocolitica, P. fluorescens, and P. putida deliberately inoculated into WBC-reduced CPD/AS-1 and CP2D/AS-3 RBCs. The results demonstrated the crucial bactericidal role of PEN110 in the INACTINE process.

Yersinia septic shock following an autologous transfusion in a pediatric patient

Although the literature on infections transmitted via transfused blood focuses on viruses, Yersinia enterocolitica can also cause severe infections in patients receiving transfusions. A 13-year-old patient developed severe sepsis after an autologous blood transfusion contaminated with Y. enterocolitica. The patient was an otherwise healthy female undergoing posterior spinal fusion for congenital scoliosis. Prior to surgery, the patient donated blood for perioperative and postoperative use. A few days before the donation, she had complained of abdominal pain and was experiencing mild diarrhea. The patient received four units of packed red blood cells (PRBCs) during the surgery. Intraoperatively, the patient developed fever up to 103.6 degrees F, became hypotensive requiring epinephrine and dopamine, and developed metabolic acidosis with serum bicarbonate concentration dropping to 16 mmol/l. The surgery team believed the patient was experiencing malignant hyperthermia and attempted to cool patient during the procedure. Postoperatively, the patient was transferred to the pediatric intensive care unit and treated for severe shock of unknown etiology. The patient further developed disseminated intravascular coagulation. The patient received supportive care and was started on ampicillin/sulbactam on postoperative day (POD) one which was changed to clindamycin, ciprofloxacin and tobramycin on POD two when blood cultures grew gram-negative bacilli. On POD three, cultures were identified as Y. enterocolitica and antibiotics were changed to tobramycin and cefotaxime based on susceptibility data. Sequelae of the shock included adult respiratory distress syndrome requiring intubation and a tracheostomy and multiple intracranial hemorrhagic infarcts with subsequent seizure disorder. Due to severe lower extremity ischemia, she required a bilateral below the knee amputation. The cultures of the snippets from the bags of blood transfused to the patient also grew Y. enterocolitica. This case illustrates the importance of considering transfusion related bacterial infections in patients receiving PRBCs. All patients in shock following any type of transfusion may require aggressive antibiotic therapy, until the diagnosis and etiology are known.

Identification of Yersinia-infected blood donors by anti-Yop IgA immunoassay

BACKGROUND

From 1991 through 1996, nine transfusion-related cases of septicemia and endotoxemia occurred in New Zealand, a rate approximately 80 times that in the United States. Eight cases involved the transfusion of Yersinia enterocolitica-infected blood and one involved Serratia liquefaciens-infected blood. Six of the recipients died. Donor exclusion by recent gastrointestinal illness failed to prevent the four most recent such infections, and it has led to an estimated 3- to 5-percent rate of donor deferral.

STUDY DESIGN AND METHODS

An antigen preparation containing the released proteins (Yops) of Y. enterocolitica was used to establish an EIA to detect IgA directed against these proteins in donated blood. The assay was tested with serum from donors in transfusion-related endotoxemia cases, subjects who were stool culture-positive for Y. enterocolitica, and 495 healthy volunteer blood donors.

RESULTS

The assay detected anti-Yop IgA in the donors of all 6 infected units tested. Ninety-six percent of culture-positive subjects tested positive, whereas there was 70-percent positivity with a commercial immunoassay based on lipopolysaccharide. Five percent of random donors tested positive; only one of these had Y. enterocolitica present in a stool sample, and none were bacteremic.

CONCLUSION

The anti-Yop immunoassay used in this study could be applied to reduce the risk of posttransfusion endotoxic shock caused by Y. enterocolitica.

Determinants of transfusion-associated bacterial contamination: results of the French BACTHEM Case-Control Study

BACKGROUND

Transfusion-associated bacterial contamination (TABC), probably the most frequent transfusion-transmitted infection, may induce serious adverse events. Systematic information and documentation on determinants are lacking.

STUDY DESIGN AND METHODS

The BACTHEM Study is a French matched case-control study assessing TABC determinants. Included were cases of TABC reported in France in a 2-year period, as determined from uniform definitions. Information on recipient-, blood component-, and donor-related potential determinants was collected on site. ORs were estimated by conditional logistic regression.

RESULTS

Of the 158 cases of suspected TABC reported, 41 that involved transfusion with 25 RBCs and 16 platelet concentrates were included. Gram-negative rods accounted for nearly half of the bacteria species involved and for all six deaths. In comparison with the risk of TABC for patients receiving RBCs for anemia, the risk was higher for patients receiving RBCs for pancytopenia (OR, 7.3; 95% CI, 1.3-41.0) and for those receiving platelets for thrombocytopenia (OR, 5.3; 95% CI, 1.2-24.1). Other potential determinants were platelet transfusion for pancytopenia (OR, 4.5; 95% CI, 0.5-40.0), immunosuppressive treatment (OR, 2.8; 95% CI, 0.7-10.6), shelf-life of more than 1 day for platelets or 8 days for RBCs (OR, 2.6; 95% CI, 0.7-9.6), and more than 20 previous donations by donors (OR, 1.9; 95% CI, 0.7-5.3).

CONCLUSION

This first comparative study revealed TABC determinants that suggest approaches for prevention.

Bacteriological and serological findings in a further case of transfusion-mediated Yersinia enterocolitica sepsis

A 13-year-old patient developed severe shock due to administration of a Yersinia enterocolitica-contaminated red blood cell concentrate. Y. enterocolitica (serotype O:9, biotype II) was cultivated from the residual blood in the blood bag and from a stool sample of the blood donor. In the donor's plasma immunoglobulin M (IgM), IgA, and IgG antibodies against Yersinia outer proteins (YopM, -H, -D, and -E) were found. Since the donor remembered a short-lasting, mild diarrhea 14 days prior to blood donation, a transient attack of Yersinia enteritis may be associated with a longer than expected period of asymptomatic bacteremia that causes contamination of donor blood. Serological screening for IgM antibodies against Yersinia outer proteins might offer a way to reduce the risk of transfusion-associated Y. enterocolitica sepsis.

Preparation and preservation of red cells

BACKGROUND

The production of blood components has undergone several changes during the last decades.

METHODS

Red blood cells will have slightly different properties depending on the way of preparation: whether a hard or soft spin has been used, whether platelets and/or leukocytes have been removed or not, and whether the red cells have been suspended in part of the original plasma or in an additive solution. Automated techniques are now often used for the separation of buffy coats, red cells and plasma. Recently, apheresis techniques have been applied for the preparation of red cells, mostly in combination with plasma or platelets. Continuous addition of the anticoagulant during collection reduces the delay between collection and separation, but the cost is higher and donor time longer.

RESULTS

Most of the methods for the preparation and storage of red cells allow 35-42 days of storage with a mean in vivo recovery of > 75%. However, the content of erythrocyte 2,3-DPG is commonly lost within 1-2 weeks, caused by the accumulation of acid metabolites, but can be maintained longer with new systems of storage. Leukodepletion of red cells by filtration is used increasingly, but its importance in the majority of transfusions is still unclear.

CONCLUSION

New options for the preparation and storage of red blood cells are available and undergo continuous evaluation.