Content of reduced glutathione and consequences in recipients of glucose-6-phosphate dehydrogenase deficient red blood cells

Blood Donors with Thalassemic Trait, Glucose-6-Phosphate Dehydrogenase Deficiency Trait, and Sickle Cell Trait and Their Blood Products: Current Status and Future Perspective

The use of blood products for different medical purposes has increased in recent years. To meet increasing demand, some blood centers allow volunteer donors with thalassemic trait, glucose-6-phosphate dehydrogenase deficiency (G6PD) trait, and sickle cell trait (SCT) to donate blood if their hemoglobin values fall within acceptable ranges and show no signs of hemolysis. Currently, there are no standard guidelines or policies regarding the use or management of blood products obtained from these donors. However, in recent years, there has been advanced research on eligible donors who have these underlying conditions. In this review, we summarize the current knowledge from in vitro and in vivo studies regarding donor characteristics, changes in physical and biochemical parameters in blood products during processing and storage, and posttransfusion efficacy of blood products. In addition, we discuss some unresolved issues concerning blood products from thalassemic trait, G6PD-deficiency trait, and SCT donors.

Impact of G6PD status on red cell storage and transfusion outcomes

There are inter-individual differences in the quality of refrigerator-stored red blood cells (RBCs). Possible sources of these variations include nutritional and genetic factors. Glucose-6-phosphate dehydrogenase (G6PD) deficiency, the most common enzyme deficiency worldwide that affects the ability of RBCs to respond to oxidative stress, has been implicated as a genetic factor that affects the quality of stored RBCs. This review considers the literature concerning G6PD-deficient RBCs. It discusses RBC unit variables such as in vitro storage, 24-hour post-transfusion recovery (PTR), post-transfusion survival, and post-transfusion clinical outcomes.There are several differences in the in vitro storage characteristics between G6PD-deficient and G6PD-normal RBCs. Recent studies identified differences in the pathways related to glycolysis, purine metabolism, glutathione homeostasis, and fatty acid metabolism. In vitro experiments modelling the transfusion of G6PD-deficient RBCs, as well as autologous PTR studies in vivo, demonstrate increased haemolysis and decreased PTR, respectively, both indicators of a decrease in quality as compared to G6PD-normal RBCs. Finally, studies transfusing G6PD-deficient and G6PD-normal RBCs show that, in certain clinical settings, G6PD-deficient RBCs are associated with increased haemolysis.In summary, G6PD deficiency is associated with a decrease in the quality of RBCs after storage and its impact is often under-estimated. Understanding the underlying mechanisms by which G6PD deficiency affects RBC storage and transfusion outcomes may provide important clues to help optimise the future efficacy and safety of transfusions.

Red blood cell transfusion in surgical cancer patients: Targets, risks, mechanistic understanding and further therapeutic opportunities

Anemia is present in more than half of cancer patients and appears to be an independent prognostic factor of short- and long-term adverse outcomes. It increases in the advanced period of cancer and perioperatively, in patients with solid tumors who undergo surgery. As a result, allogeneic red blood cell (RBC) transfusion is an indispensable treatment in cancer. However, its safety remains controversial, based on several laboratory and clinical data reporting a linkage with increased risk for cancer recurrence, infection and cancer-related mortality. Immunological, inflammatory and thrombotic reactions mediated by the residual leukocytes and platelets, the stored RBCs per se, the biological response modifiers and the plasticizer of the unit may underlie infection and tumor-promoting effects. Although the causality between transfusion and infection has been established, the effects of transfusion on cancer recurrence remain confusing; this is mainly due to the extreme biological heterogeneity that characterizes RBC donations and cancer context. In fact, the functional interplay between donation-associated factors and recipient characteristics, including tumor biology per se, inflammation, infection, coagulation and immune activation state and competence may synergistically and individually define the clinical impact of each transfusion in any given cancer patient. Our understanding of how the potential risk is mediated is important to make RBC transfusion safer and to pave the way for novel, promising and highly personalized strategies for the treatment of anemia in surgical cancer patients.

Glucose 6-phosphate dehydrogenase deficient subjects may be better "storers" than donors of red blood cells

Storage of packed red blood cells (RBCs) is associated with progressive accumulation of lesions, mostly triggered by energy and oxidative stresses, which potentially compromise the effectiveness of the transfusion therapy. Concerns arise as to whether glucose 6-phosphate dehydrogenase deficient subjects (G6PD(-)), ~5% of the population in the Mediterranean area, should be accepted as routine donors in the light of the increased oxidative stress their RBCs suffer from. To address this question, we first performed morphology (scanning electron microscopy), physiology and omics (proteomics and metabolomics) analyses on stored RBCs from healthy or G6PD(-) donors. We then used an in vitro model of transfusion to simulate transfusion outcomes involving G6PD(-) donors or recipients, by reconstituting G6PD(-) stored or fresh blood with fresh or stored blood from healthy volunteers, respectively, at body temperature. We found that G6PD(-) cells store well in relation to energy, calcium and morphology related parameters, though at the expenses of a compromised anti-oxidant system. Additional stimuli, mimicking post-transfusion conditions (37°C, reconstitution with fresh healthy blood, incubation with oxidants) promoted hemolysis and oxidative lesions in stored G6PD(-) cells in comparison to controls. On the other hand, stored healthy RBC units showed better oxidative parameters and lower removal signaling when reconstituted with G6PD(-) fresh blood compared to control. Although the measured parameters of stored RBCs from the G6PD deficient donors appeared to be acceptable, the results from the in vitro model of transfusion suggest that G6PD(-) RBCs could be more susceptible to hemolysis and oxidative stresses post-transfusion. On the other hand, their chronic exposure to oxidative stress might make them good recipients, as they better tolerate exposure to oxidatively damaged long stored healthy RBCs.

Donor-variation effect on red blood cell storage lesion: A close relationship emerges

Although the molecular pathways leading to the progressive deterioration of stored red blood cells (RBC storage lesion) and the clinical relevance of storage-induced changes remain uncertain, substantial donor-specific variability in RBC performance during storage, and posttransfusion has been established ("donor-variation effect"). In-bag hemolysis and numerous properties of the RBC units that may affect transfusion efficacy have proved to be strongly donor-specific. Donor-variation effect may lead to the production of highly unequal blood labile products even when similar storage strategy and duration are applied. Genetic, undiagnosed/subclinical medical conditions and lifestyle factors that affect RBC characteristics at baseline, including RBC lifespan, energy metabolism, and sensitivity to oxidative stress, are all likely to influence the storage capacity of individual donors' cells, although not evident by the donor's health or hematological status at blood donation. Consequently, baseline characteristics of the donors, such as membrane peroxiredoxin-2 and serum uric acid concentration, have been proposed as candidate biomarkers of storage quality. This review article focuses on specific factors that might contribute to the donor-variation effect and emphasizes the emerging need for using omics-based technologies in association with in vitro and in vivo transfusion models and clinical trials to discover biomarkers of storage quality and posttransfusion recovery in donor blood.

Should blood donors be routinely screened for glucose-6-phosphate dehydrogenase deficiency? A systematic review of clinical studies focusing on patients transfused with glucose-6-phosphate dehydrogenase-deficient red cells

The risk factors associated with the use of glucose-6-phosphate dehydrogenase (G6PD)-deficient blood in transfusion have not yet been well established. Therefore, the aim of this review was to evaluate whether whole blood from healthy G6PD-deficient donors is safe to use for transfusion. The study undertook a systematic review of English articles indexed in COCHRANE, MEDLINE, EMBASE, and CINHAL, with no date restriction up to March 2013, as well as those included in articles' reference lists and those included in Google Scholar. Inclusion criteria required that studies be randomized controlled trials, case controls, case reports, or prospective clinical series. Data were extracted following the Preferred Reporting Items for Systematic Reviews using a previously piloted form, which included fields for study design, population under study, sample size, study results, limitations, conclusions, and recommendations. The initial search identified 663 potentially relevant articles, of which only 13 studies met the inclusion criteria. The reported effects of G6PD-deficient transfused blood on neonates and children appear to be more deleterious than effects reported on adult patients. In most cases, the rise of total serum bilirubin was abnormal in infants transfused with G6PD-deficient blood from 6 hours up to 60 hours after transfusion. All studies on neonates and children, except one, recommended a routine screening for G6PD deficiency for this at-risk subpopulation because their immature hepatic function potentially makes them less able to handle any excess bilirubin load. It is difficult to make firm clinical conclusions and recommendations given the equivocal results, the lack of standardized evaluation methods to categorize red blood cell units as G6PD deficient (some of which are questionable), and the limited methodological quality and low quality of evidence. Notwithstanding these limitations, based on our review of the available literature, there is little to suggest that G6PD-deficient individuals should be excluded from donating red blood cells, although transfusions of such blood may potentially have negative impacts on premature neonates or patients who need repeated transfusions, and thus, for this group, screening for G6PD deficiency may be appropriate.

Glucose-6-phosphate dehydrogenase deficiency in transfusion medicine: the unknown risks

The hallmark of glucose-6-phosphate dehydrogenase (G6PD) deficiency is red blood cell (RBC) destruction in response to oxidative stress. Patients requiring RBC transfusions may simultaneously receive oxidative medications or have concurrent infections, both of which can induce haemolysis in G6PD-deficient RBCs. Although it is not routine practice to screen healthy blood donors for G6PD deficiency, case reports identified transfusion of G6PD-deficient RBCs as causing haemolysis and other adverse events. In addition, some patient populations may be more at risk for complications associated with transfusions of G6PD-deficient RBCs because they receive RBCs from donors who are more likely to have G6PD deficiency. This review discusses G6PD deficiency, its importance in transfusion medicine, changes in the RBC antioxidant system (of which G6PD is essential) during refrigerated storage and mechanisms of haemolysis. In addition, as yet unanswered questions that could be addressed by translational and clinical studies are identified and discussed.

Safety of hematopoietic stem cell donation in glucose 6 phosphate dehydrogenase-deficient donors

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common RBC enzymatic disorder in humans capable of producing hemolytic events. Recently, concern has been raised about using G6PD-deficienct subjects as hemopoietic stem cell (HSC) donors. In a 10-year period, 101 consecutive HSC donors were submitted to donation procedures for transplantation inside their families in our Center. All donors were tested for G6PD and 19 (19%) turned out to be G6PD-deficient. The donors' safety and the effectiveness of these transplant outcomes were compared with those of the remaining 82 donors. No difference could be observed in any safety parameter between the two groups. No difference was recorded in donors' complications rates, in HSC production, in quantity of growth factor required, in Hb early drop or in Hb recovery. No difference was found in transplant outcome. From this retrospective analysis, we conclude that a G6PD-deficient but otherwise healthy volunteer can be selected as a HSC donor.

Prevalence of glucose-6-phosphate dehydrogenase deficiency and sickle cell trait among blood donors in Riyadh

Background and Aims:

Blood donation from glucose-6-phosphate dehydrogenase (G6PD)-deficient and sickle cell trait (SCT) donors might alter the quality of the donated blood during processing, storage or in the recipient's circulatory system. The aim of this study was to determine the prevalence of G6PD deficiency and SCT among blood donors coming to King Khalid University Hospital (KKUH) in Riyadh. It was also reviewed the benefits and risks of transfusing blood from these blood donors.

Materials and Methods:

This cross-sectional study was conducted on 1150 blood samples obtained from blood donors that presented to KKUH blood bank during the period April 2006 to May 2006. All samples were tested for Hb-S by solubility test, alkaline gel electrophoresis; and for G6PD deficiency, by fluorescent spot test.

Results:

Out of the 1150 donors, 23 (2%) were diagnosed for SCT, 9 (0.78%) for G6PD deficiency and 4 (0.35%) for both conditions. Our prevalence of SCT and G6PD deficiency is higher than that of the general population of Riyadh.

Conclusion:

We recommend to screen all units for G6PD deficiency and sickle cell trait and to defer donations from donors with either of these conditions, unless if needed for special blood group compatibility, platelet apheresis or if these are likely to affect the blood bank inventory. If such blood is to be used, special precautions need to be undertaken to avoid complications in high-risk recipients.

Screening for glucose-6-phosphate dehydrogenase deficiency in blood donors

AIM

Our purpose was to determine the frequency of glucose-6-phosphate dehydrogenase (G6PD) deficiency in blood donors of Jahrom, Iran.

METHODS

Blood samples were obtained from the 706 blood donors who referred to Jahrom Blood Transfusion Organization between June and September 2008. Enzyme assays were performed three times, on day 1 (day of blood sampling), 7 and 45 days after blood storage. G6PD activity was measured using a quantitative assay.

RESULTS

A total of 706 samples were examined. 97.7% males and 2.3% females, mean age 32.6 years (18-64 years). Based on enzyme activity less than 1.62 IU/g hemoglobin (Hb), prevalence of G6PD deficiency in three separate measurements was 16.3, 19.1 and 33.3% respectively. Four percent of donor had an enzyme level of zero on day 1 which increased to 7.4 and 10.7% on the seventh and the forty-fifth days.

CONCLUSION

The results of this study support the screening for G6PD as part of the routine workup of blood donors in areas with a high prevalence of G6PD deficiency.

Alternations in quantities and activities of erythrocyte cytosolic carbonic anhydrase isoenzymes in glucose-6-phosphate dehydrogenase-deficient individuals

BACKGROUND

This study was designed to evaluate the quantitative and activity alterations of cytosolic carbonic anhydrase (CA) isoenzymes in the erythrocytes of glucose-6-phosphate dehydrogenase (G6PD)-deficient individuals.

METHODS

Western Blot and CA esterase activity analysis were employed to measure cytosolic erythrocyte CA isoenzymes.

RESULTS

The total CA activities were analyzed from erythrocytes of 30 healthy and 30 G6PD-deficient individuals. The mean values with standard error (SE) were 22.9+/-1.69 U/gHb and 27.2+/-2.1 U/gHb (P<0.01), respectively. The ratio of CAI/CAII of G6PD-deficient individuals (1.28+/-0.06) was significantly lower than that of the normal subjects (3.79+/-0.18) (P<0.001). Furthermore, the concentration of CAIII in G6PD-deficient individuals was significantly lower than that of the normal subjects (P<0.001) and there were significant correlations between the concentration of CAI, CAII, CAIII, and ratio of CAI/CAII, and the activity concentration of G6PD.

CONCLUSIONS

Different carbonic anhydrase isoenzymes may serve different roles in the G6PD-deficient erythrocyte. CAI could be used as an indicator for hemolytic anemia. CAII is able to compensate for the functions of CAI and increased expression of CAII will promote oxidative damage. CAIII can provide the G6PD-deficient persons with some extent of protection against oxidative damage.

Variations of the bilirubin uridine-diphosphoglucuronosyl transferase 1A1 gene in healthy Taiwanese

The activity of uridine-diphosphoglucuronosyl transferase 1 (UGT1) may influence the concentration of serum bilirubin. Because UGT1 is too labile to be measured with classical biochemical methods, we analysed the whole UGT1A1 gene in 290 healthy Taiwanese adults by using the polymerase chain reaction method, and investigated the relationship between UGT1A1 genotypes and serum bilirubin levels. The results showed that slightly more than 50% of the subjects had one or more variant sites in UGT1A1 gene. The most common variant was A(TA)6TAA/A(TA)7TAA (6/7) in the promoter area, followed by heterozygous variation within the coding region, compound heterozygous and homozygous variations. Among the four variant sites within the coding region, 211 G to A was the predominate one, 1091 C to T was a novel variation, and 686 C to A was associated with 6/7. Subjects with 6/7 or heterozygous variation within the coding region or compound heterozygous (plus one homozygous) variation had significantly higher bilirubin levels than those with wild UGT1A1 gene. When the 290 subjects were stratified into six groups according to their serum bilirubin concentrations, the bilirubin levels were correlated well to the frequencies of variant UGT1A1 gene. Our results show that there is a strong association between UGT1A1 gene and bilirubin levels in healthy Taiwanese adults. The occurrence of A(TA)7TAA allele was relatively rare and the variation rate within the coding region was much higher in Taiwanese compared to that in Caucasians.

Glucose-6-phosphate dehydrogenase deficiency

Glucose-6-phosphate dehydrogenase (G6PD) is expressed in all tissues, where it catalyses the first step in the pentose phosphate pathway. G6PD deficiency is prevalent throughout tropical and subtropical regions of the world because of the protection it affords during malaria infection. Although most affected individuals are asymptomatic, there is a risk of neonatal jaundice and acute haemolytic anaemia, triggered by infection and the ingestion of certain drugs and broad beans (favism). A rare but more severe form of G6PD deficiency is found throughout the world and is associated with chronic non-spherocytic haemolytic anaemia. Many deficient variants of G6PD have been described. DNA sequence analysis has shown that the vast majority of these are caused by single amino acid substitutions. The three-dimensional structure of G6PD shows a classical dinucleotide binding domain and a novel beta + alpha domain involved in dimerization.