Long-term transfusion of polymerized bovine hemoglobin in a Jehovah's Witness following chemotherapy for myeloid leukemia: a case report

New Applications of HBOC-201: A 25-Year Review of the Literature

If not cured promptly, tissue ischemia and hypoxia can cause serious consequences or even threaten the life of the patient. Hemoglobin-based oxygen carrier-201 (HBOC-201), bovine hemoglobin polymerized by glutaraldehyde and stored in a modified Ringer's lactic acid solution, has been investigated as a blood substitute for clinical use. HBOC-201 was approved in South Africa in 2001 to treat patients with low hemoglobin (Hb) levels when red blood cells (RBCs) are contraindicated, rejected, or unavailable. By promoting oxygen diffusion and convective oxygen delivery, HBOC-201 may act as a direct oxygen donor and increase oxygen transfer between RBCs and between RBCs and tissues. Therefore, HBOC-201 is gradually finding applications in treating various ischemic and hypoxic diseases including traumatic hemorrhagic shock, hemolysis, myocardial infarction, cardiopulmonary bypass, perioperative period, organ transplantation, etc. However, side effects such as vasoconstriction and elevated methemoglobin caused by HBOC-201 are major concerns in clinical applications because Hbs are not encapsulated by cell membranes. This study summarizes preclinical and clinical studies of HBOC-201 applied in various clinical scenarios, outlines the relevant mechanisms, highlights potential side effects and solutions, and discusses the application prospects. Randomized trials with large samples need to be further studied to better validate the efficacy, safety, and tolerability of HBOC-201 to the extent where patient-specific treatment strategies would be developed for various clinical scenarios to improve clinical outcomes.

Treatment of acute leukaemia in adult Jehovah's Witnesses

Since Jehovah's Witness (JW) patients diagnosed with leukaemia refuse blood transfusions, they are often denied intensive chemotherapy for fear they could not survive myeloablation without blood transfusion support. Treatment of JW patients with acute leukaemia is challenging and carries a higher morbidity and mortality; however, the refusal of blood products should not be an absolute contraindication to offer multiple treatment modalities including haematopoietic stem cell transplantation. In this review we discuss their optimal management and describe alternative modalities to blood transfusions to provide sufficient oxygenation and prevent bleeding.

Treatment of individuals who cannot receive blood products for religious or other reasons

By virtue of their religious principles, Jehovah's Witnesses (JWs) generally object to receiving blood products, raising numerous ethical, legal, and medical challenges for providers who care for these patients, especially in the emergent setting. In this review, we discuss several areas relevant to the care of JWs, including the current literature on "bloodless" medical care in the setting of perioperative and intraoperative management, acute blood loss, trauma, pregnancy, and malignancy. We have found that medical and administrative efforts in the form of bloodless medicine and surgery programs can be instrumental in helping to reduce risks of morbidity and mortality in these patients. Planning prior to an anticipated event associated with blood loss or anemia (such as elective surgery, pregnancy, and chemotherapy) is critical. Specifically, bloodless medicine programs should prioritize vigilant early screening and management of anemias, early establishment of patient wishes regarding transfusion, and the incorporation of those wishes into multidisciplinary medical and surgical care. Although there are now a variety of human-based and nonhuman-based products available as transfusion alternatives, the degree and quality of evidence to support their use varies significantly between products and is also largely dependent on the clinical setting.

A Jehovah's Witness with Acute Myeloid Leukemia Successfully Treated with an Epigenetic Drug, Azacitidine: A Clue for Development of Anti-AML Therapy Requiring Minimum Blood Transfusions

Therapy for acute leukemia in Jehovah's Witnesses patients is very challenging because of their refusal to accept blood transfusions, a fundamental supportive therapy for this disease. These patients are often denied treatment for fear of treatment-related death. We present the first Jehovah's Witness patient with acute myeloid leukemia (AML) treated successfully with azacitidine. After achieving complete remission (CR) with one course of azacitidine therapy, the patient received conventional postremission chemotherapy and remained in CR. In the case of patients who accept blood transfusions, there are reports indicating the treatment of AML patients with azacitidine. In these reports, azacitidine therapy was less toxic, including hematoxicity, compared with conventional chemotherapy. The CR rate in azacitidine-treated patients was inadequate; however, some characteristics could be useful in predicting azacitidine responders. The present case is useful for treating Jehovah's Witnesses patients with AML and provides a clue for anti-AML therapy requiring minimum blood transfusions.

Oxygen therapeutics: pursuit of an alternative to the donor red blood cell

CONTEXT

There is no true substitute for the many functions of human red blood cells, and synthetic products will not replace the need for blood donation in the foreseeable future. Hemoglobin-based oxygen carriers have many characteristics that would serve as a useful adjunct to red cells in clinical settings. Over time, these technologies have the potential to dramatically reshape the practice of transfusion medicine.

OBJECTIVE

To review the characteristics and potential utility of hemoglobin-based oxygen carriers and perfluorocarbon-based oxygen carriers. Several hemoglobin-based oxygen carriers are under study in phase III clinical trials. Novel uses for synthetic oxygen therapeutics are emphasized.

DATA SOURCES

All published reports with the key words oxygen therapeutics, blood substitutes, and red cell substitutes from 1933 until March 2006 were searched through Medline. Significant findings were synthesized.

CONCLUSIONS

Recognition of the true impact of red cell substitutes is still several years away. The most compelling products, hemoglobin-based oxygen carriers, have potential use in trauma, providing immediate oxygen-carrying support in the face of alloantibodies or autoantibodies, and in other clinical situations in which long-term survival of red cells is not essential. In the interim, efforts should be focused on enhancing the current blood supply system while supporting ongoing and planned blood substitute research efforts, including trials assessing novel clinical indications for these products.

Bovine hemoglobin (glutamer-250, Hemopure)-specific immunoglobulin G antibody cross-reacts with human hemoglobin but does not lyse red blood cells in vitro

BACKGROUND

Bovine hemoglobin (Hb)-based oxygen carrier (HbOC-201; Hb glutamer-250, Hemopure, Biopure Corp.) is a blood replacement and augmentation drug that increases oxygen-carrying capacity of circulating blood in patients with anemia and acute blood loss. The objective of this study was to assess the biologic significance (cross-reactivity, hemolysis) of humoral immune responses in humans receiving repetitive HbOC-201 administrations.

STUDY DESIGN AND METHODS

Serum samples containing immunoglobulin G (IgG) anti-HbOC-201 (n = 146) or no antibody (n = 16) were collected from subjects receiving HbOC-201 in clinical studies. IgG anti-HbOC-201 levels were quantified and the extent of cross-reactivity to human hemoglobin (HuHb) was assessed in direct-binding and competitive-inhibition immunoassays. Serum samples containing the highest levels of IgG anti-HbOC-201 were studied in a complement-mediated hemolysis assay for their ability to lyse human red cells (RBCs).

RESULTS

The IgG anti-HbOC-201 levels in the antibody-positive serum samples ranged from 0.7 to 86.8 mug per mL. Of the 146 IgG anti-HbOC-201-positive serum samples, 88.4 percent contained IgG antibodies whose binding to solid-phase HbOC-201 was competitively inhibited by incubation with soluble HuHb (11.6% [<20% inhibition]; 63% [20%-80% inhibition]; and 25.4% [>81% inhibition]). Direct-binding analysis to solid-phase HuHb confirmed that 74 percent contained IgG antibodies reactive with HuHb. Dichotomous competitive inhibition and direct-binding IgG anti-HuHb data correlated significantly (r(2) = 0.77, p < 0.001). Serum samples with the highest levels of IgG anti-HuHb, as identified from clinical studies, did not lyse human RBCs in the presence of exogenous complement or induce the direct sensitization of RBCs with human IgG or complement.

CONCLUSION

These analyses indicate that HbOC-201 administration elicits IgG antibodies in humans that react with bovine and HuHb, but do not cause hemolysis in vitro.

Clinical strategies in the medical care of Jehovah's Witnesses

Jehovah's Witnesses are primarily known to physicians for their refusal of blood transfusions. Conflict arises at times with the medical staff concerning how best to manage their care. This article will begin with a brief description of the beliefs of Jehovah's Witnesses and will then recommend specific clinical strategies highlighting newer potential therapies according to the principles of bloodless medicine. The scenarios of bleeding and acute and chronic anemia will be discussed in detail for the care of these patients refusing red blood cell transfusions. An update in the use of blood substitutes will be mentioned as well as the surgical advances used today that can minimize blood loss for all patients. The experience of organ transplantation in Jehovah's Witnesses will be detailed. Further resources for physicians with questions in the care of these patients will be listed. Stressed throughout the article will be the need for a team approach and good communication between physicians to successfully care for their patients who are Jehovah's Witnesses.