Properties of donated red blood cell components from patients with hereditary hemochromatosis

Blood donation for iron removal in individuals with HFE mutations: study of efficacy and safety and short review on hemochromatosis and blood donation

Background

Elevated serum ferritin with/without HFE variants in asymptomatic persons leads frequently to referral for blood donation. Hemochromatosis (p.C282Y/p.C282Y) only requires treatment. We evaluated safety and feasibility of iron removal in healthy persons with elevated ferritin and HFE variants using blood donation procedures.

Materials and methods

Thirty subjects with ferritin >200 ng/mL (women) or >300 ng/mL (men) with p.C282Y/p.C282Y, p.C282Y/p.H63D or p.H63D/p.H63D were randomized to weekly phlebotomy (removal of 450 mL whole blood) or erythrapheresis (removal of 360 mL red blood cells) every 14 days. The ferritin target was <100 ng/mL. A full blood count and ferritin were measured at each visit. Hemoglobin (Hb) ≥140 g/L was required at inclusion. If Hb dropped to <120 g/L (women) or <130 g/L (men), procedures were postponed (7 or 14 days). Primary endpoint was the number of procedures needed to the ferritin target; secondary objectives were duration of treatment and compliance. The treatment effect was tested with Poisson regression; number of procedures and treatment duration were compared between study arms with the Kruskal-Wallis test.

Results

Twenty-five of 30 participants were men (83%); mean age was 47 years (SD 10.5), mean BMI 26.6 kg/m2 (SD 3.6); 17 had p.C282Y/p.C282Y, nine p.C282Y/p.H63D, four p.H63D/p.H63D. Median baseline Hb was 150 g/L (IQR 144, 1,559), median ferritin 504 ng/mL (IQR 406,620). Twenty-seven subjects completed the study. Treatment arm (p < 0.001) and HFE variant (p = 0.007) influenced the primary endpoint significantly. To ferritin levels <100 ng/mL, a median number of 7.5 (IQR 6.2, 9.8) phlebotomies and 4.0 (IQR 3.0, 5.8) erythraphereses (p = 0.001) was needed during a median of 66.5 days (IQR 49,103) and 78.5 days (IQR 46139), respectively (p = 0.448). Low Hb was the principal reason for protocol violation; anemia occurred in 13 participants (48%). Immediate complications were infrequent; fatigue was reported after 25% of phlebotomies and 45% of erythraphereses. Thirty-five procedures were postponed because of low Hb and 15 for non-medical reasons. The median interval was 7.0 (IQR 7.7) and 14.0 (IQR 14, 20) days between phlebotomies and erythraphereses, respectively.

Conclusion

Blood donation procedures remove iron effectively in HC, but frequent treatments cause Hb decrease and fatigue that can impair feasibility.

Current Understanding of the Relationship between Blood Donor Variability and Blood Component Quality

While differences among donors has long challenged meeting quality standards for the production of blood components for transfusion, only recently has the molecular basis for many of these differences become understood. This review article will examine our current understanding of the molecular differences that impact the quality of red blood cells (RBC), platelets, and plasma components. Factors affecting RBC quality include cytoskeletal elements and membrane proteins associated with the oxidative response as well as known enzyme polymorphisms and hemoglobin variants. Donor age and health status may also be important. Platelet quality is impacted by variables that are less well understood, but that include platelet storage sensitive metabolic parameters, responsiveness to agonists accumulating in storage containers and factors affecting the maintenance of pH. An increased understanding of these variables can be used to improve the quality of blood components for transfusion by using donor management algorithms based on a donors individual molecular and genetic profile.

A comparison of platelet quality between platelets from healthy donors and hereditary hemochromatosis donors over seven-day storage

BACKGROUND

Therapeutic phlebotomy is the standard treatment of hereditary hemochromatosis (HH), the most common genetic disease in people of Northern European descent. Red cell concentrates from HH donors have been reported safe for transfusion, but little data is available on the storage properties of platelet concentrates from HH donors.

STUDY DESIGN AND METHODS

Whole blood was collected from 10 healthy individuals and 10 newly diagnosed HH patients with elevated serum ferritin. Platelet-rich plasma (PRP) was prepared and split into four 20-mL units. Platelet quality tests were performed on days 0, 1, 3, 5, and 7 of storage, including platelet aggregation (ADP, arachidonic acid, collagen, and epinephrine agonists), blood gas analysis, flow cytometry (CD41, CD42b, and CD62P expression), and ELISA (sCD40L and sCD62p in supernatant).

RESULTS

Mean serum ferritin levels were higher in HH patients than in controls (847.5 vs 45.8 ng/mL, P < .001). Overall, no difference in quality test results was observed between the two study groups over 7-day storage (P > .05), including blood gas analysis, platelet aggregation, and expression of surface (CD62p and CD42b) and secreted (sCD62P and sCD40L) activation markers. Expected alterations in metabolic (CO₂ and glucose decrease, O₂ and lactate increase, P < .001) and platelet activation markers (CD42b decrease, CD62P increase, P < .05) over time were observed in both groups.

CONCLUSION

Although these findings indicate that platelets of individuals with HH are comparable to platelets from healthy donors, more extensive studies are needed before definite conclusions can be drawn.

Mechanical sensitivity of red blood cells improves in individuals with hemochromatosis following venesection therapy

BACKGROUND

Individuals with hereditary hemochromatosis (HH) receive frequent blood withdrawals (ie, venesections) as part of their primary treatment to assist in normalizing blood iron levels. It remains unclear whether this source of blood is suitable for use in blood product development, as current data indicate that red blood cell (RBC) deformability, both before and after shear stress exposure, is impaired in individuals with HH, relative to healthy controls. Given that venesection therapy is known to significantly reduce circulating iron levels in individuals with HH, the current study examined whether venesection therapy is effective at improving RBC mechanical properties, both before and after shear stress exposure, in individuals with HH.

STUDY DESIGN AND METHODS

Blood samples were initially collected from untreated HH patients (age, 61 ± 9 years; 14% female) undergoing their first venesection, and then again during their second (approx. 9 weeks later) and third (approx. 16 weeks later) venesections. RBC deformability was measured at each time point with a commercial ektacytometer. Moreover, to determine cell responses to mechanical stimuli, the mechanical sensitivity of blood samples was determined at each time point.

RESULTS

The salient findings indicate that venesection therapy used for managing plasma ferritin concentration significantly improves the cellular deformability of RBC in individuals with HH. Further, the sensitivity of RBC to supraphysiological mechanical stress is decreased (ie, improved) in a dose-response fashion with routine venesection.

CONCLUSION

While cellular mechanics of RBC from individuals with HH are impaired when untreated, venesection therapy significantly improves cellular properties of RBC, supporting the use of venesections in blood product development from individuals with well-managed HH.

Diagnosis and management of hereditary haemochromatosis

Hereditary haemochromatosis, one of the most common genetic disorders in the United States, can produce systemic iron deposition leading to end-organ failure and death if untreated. The diagnosis of this condition can be challenging as elevated serum ferritin may be seen in a variety of conditions, including acute and chronic liver disease, a range of systemic inflammatory states, and both primary and secondary iron overload syndromes. Appropriate and timely diagnosis of haemochromatosis is paramount as simple interventions, such as phlebotomy, can prevent or reverse organ damage from iron overload. The recognition of other aetiologies of elevated ferritin is also vital to ensure that appropriate intervention is provided and phlebotomy only utilized in patients who require it. In this review, we summarize the existing data on the work up and management of hereditary haemochromatosis and present a practical algorithm for the diagnosis and management of this disease.

Reassessing the safety concerns of utilizing blood donations from patients with hemochromatosis

Hereditary hemochromatosis (HH) is a genetic disorder of iron metabolism that may lead to iron overload. Clinical penetrance is low, however those afflicted may develop cirrhosis, hepatocellular carcinoma, diabetes mellitus, and cardiomyopathy. Treatment of HH involves regular phlebotomy to reduce the systemic iron burden. In many countries-including the United States-numerous blood centers do not accept donated blood obtained from HH patients during therapeutic phlebotomy and there are inconsistent positions regarding this globally. This refusal of blood is borne out of a few concerns. First, there is a theoretical increase in the infectious risk of these blood products, particularly by siderophilic organisms such as Yersinia enterocolitica. Second, given the increased incidence of hepatitis C infection from nonvoluntary donors in the 1970s, there is a concern that blood units from HH donors may harbor additional risk given the nonvoluntary nature of their presentation. In this review, we examine the existing biological and clinical data concerning infectious risk and summarize clinical experience from centers allowing HH donors, and demonstrate that blood from HH patients is safe and should be allowed into the donor pool. We conclude that there is no convincing evidence to exclude this population from serving as blood donors. (Hepatology 2018;67:1150-1157).

Modeling the effect of platelet concentrate supernatants on endothelial cells: focus on endocan/ESM-1

BACKGROUND

Platelets (PLTs) are prone to activation and the release of biologic response modifiers (BRMs) under storage conditions. The transfusion inflammatory reaction in the vascular compartment involves endothelial cell activation due to cell-cell interactions and BRMs infused with the blood products. Endocan/ESM-1 is a proteoglycan secreted by endothelial cells under the control of proinflammatory cytokines. We aimed to measure endocan activity in supernatants of PLT components (PCs), implicated in serious adverse reactions (SARs) or not (no.AR), sampled at different stages during storage.

STUDY DESIGN AND METHODS

PLT function, by quantification of soluble CD62P, and their ability to produce endocan were assessed. Functional testing of PC supernatants was performed on EA.hy926 endothelial cells in vitro by exposing them to PC supernatants from each group (no.AR or SARs); EA.hy926 activation was evaluated by their production of interleukin (IL)-6 and endocan.

RESULTS

PLT endocan secretion was not induced in response to PLT surface molecule agonists, and no significant correlation was observed between sCD62P and endocan concentration after PLT activation. However, we observed a significant increase in the secretion of IL-6 and endocan after EA.hy926 activation by all PC supernatants. IL-6 and endocan secretion were significantly higher for cells stimulated with SAR than those stimulated with no.AR PC supernatants, as well as cell apoptosis.

CONCLUSION

The correlation between the secretion of endocan and that of IL-6 by endothelial cells suggests that endocan can be used as a predictive marker of inflammation for the quality assessment of transfusion grade PLTs.

Duration of red blood cell storage and inflammatory marker generation

Red blood cell (RBC) transfusion is a life-saving treatment for several pathologies. RBCs for transfusion are stored refrigerated in a preservative solution, which extends their shelf-life for up to 42 days. During storage, the RBCs endure abundant physicochemical changes, named RBC storage lesions, which affect the overall quality standard, the functional integrity and in vivo survival of the transfused RBCs. Some of the changes occurring in the early stages of the storage period (for approximately two weeks) are reversible but become irreversible later on as the storage is extended. In this review, we aim to decipher the duration of RBC storage and inflammatory marker generation. This phenomenon is included as one of the causes of transfusion-related immunomodulation (TRIM), an emerging concept developed to potentially elucidate numerous clinical observations that suggest that RBC transfusion is associated with increased inflammatory events or effects with clinical consequence.

Red blood cell components: time to revisit the sources of variability

Quality and safety of red blood cell (RBC) components is managed by screening of donors and strict regulatory controls of blood collection, processing and storage procedures. Despite these efforts, variations in RBC component quality exist as exemplified by the wide range in storage-induced haemolysis. This article provides a brief overview of the variables that contribute or potentially contribute to the quality of stored RBC components, including blood collection, processing, and donor-related variables. Particular focus is made on donor health and lifestyle factors that are not specifically screened and may impact on the physicobiochemical properties of RBCs and their storability. Inflammatory and oxidative stress states may be especially relevant as RBCs are susceptible to oxidative injury. Few studies have investigated the effect of specific donor-related variables on the quality of stored RBC components. Donor-related variables may be unaccounted confounders in the "age of blood" clinical studies that compared outcomes following transfusion of fresher or longer-stored RBC components. The conclusion is drawn that the blood donor is the greatest source of RBC component variability and the least "regulated" aspect of blood component production. It is proposed that more research is needed to better understand the connection between donor-related variables and quality consistency of stored RBC components. This could be very important given the impact of modern lifestyles that sees escalating rates of non-communicable health conditions that are associated with increased oxidative stress, such as hypertension, obesity and diabetes in children and adults, as well as an ageing population in many countries. The effect of these changes to global health and population demographics will impact on blood donor panels, and without significant new research, the consequences on the quality of stored blood components and transfusion outcomes are unknown.