Transfusion-associated graft-versus-host disease

CHAPTER 6 Transfusion-associated graft-versus-host disease Eric A. Gehrie, 1 Edward L. Snyder, 1 & Alex B. Ryder 2 1 Department of Laboratory Medicine, Yale School of Medicine, Yale University; and Blood Bank, Yale-New Haven Hospital, New Haven, CT, USA 2 Department of Pediatrics and Department of Pathology, University of Tennessee Health Science Center, La Bonheur Children s Hospital, TN, USA Transfusion-associated graft-versus-host disease (TA-GVHD) is a rare but almost uniformly lethal complication of blood transfusion. Although the graft-versus-host disease (GVHD) that occurs after allogeneic bone marrow transplantation and TA-GVHD share some clinical similarities, GVHD after bone marrow transplant is not uncommon and often responds positively to immunosuppression. 1 The much rarer TA-GVHD, however, in contradistinction to bone marrow GVHD, is associated with destruction of the recipient s bone marrow, does not respond to immunosuppressive therapy, 1 and is generally fatal. 2 Because there are no effective treatments for TA- GVHD, management of this complication focuses almost entirely on prevention by irradiation of cellular blood components (whole blood, red blood cells [RBCs], granulocytes, and platelets) that are intended for susceptible recipients. Over the past 1 15 years, the use of irradiation in high-risk situations has reduced the incidence of TA-GVHD in the Western world and Japan to almost undetectable levels. In this chapter, we review the pathophysiology and incidence of TA-GVHD, characteristics of blood transfusion recipients that make them susceptible to the development of TA-GVHD, and strategies to prevent, diagnose, and treat TA-GVHD. Pathophysiology of TA-GVHD The development of TA-GVHD requires infusion of viable allogeneic donor ( nonself ) lymphocytes, which subsequently engraft, proliferate, and attack recipient ( self ) tissues. Unlike GVHD, in which the transplanted donor hematopoietic cells in the engrafted marrow are the cells that mediate the attack on host (recipient) tissues, TA-GVHD results in destruction of both the host tissues and host bone marrow by donor T lymphocytes that engraft in the recipient following transfusion. It is the host bone marrow aplasia that occurs only in TA-GVHD that drives its lethality. The biologic basis for the differentiation of self and nonself is based on immune recognition of specific cell surface proteins, most importantly human leukocyte antigens (HLA), which are expressed on the surface of both immune and non-immune cell types. In most situations, transfused donor lymphocytes are identified by the host immune system due to their expression of non-self HLA proteins. The recognition of non-self HLA proteins by the host immune system usually leads to attack and death of donor lymphocytes contained in the transfused unit of blood or platelets. However, in rare situations, transfused donor lymphocytes are not recognized as non-self by the recipient immune system. If the transfused donor lymphocytes are sufficiently viable to engraft and proliferate within the recipient, TA-GVHD can result. Partially because TA-GVHD is exceptionally rare, the precise circumstances needed to induce TA-GVHD are not known. Transfusion-associated microchimerism (TA-MC) is a condition that occurs after transfusion of cellular blood components, in which a small number of donor allogeneic lymphocytes proliferate within a host and remain detectable for years. TA-MC is associated with perhaps 1% of patients transfused after sustaining traumatic injury, but is not known to have any clinical sequelae. 3 Distinguishing the factors that influence why T-lymphocyte engraftment sometimes results in severe disease (TA-GVHD), and sometimes results in no disease manifestations (TA-MC), is the subject of ongoing investigation. In many cases, the presence of severe acquired or congenital immune deficiency in the transfusion recipient serves as a prerequisite to the development of TA-GVHD. TA-GVHD, however, has also been reported to occur in the absence of a recognized immune deficiency, particularly in situations where the blood donor is homozygous for HLA antigens for which the recipient is heterozygous. 2 In this scenario, all HLA antigens expressed by the donor are also expressed by the host, but the host expresses HLA antigens that are not expressed by the donor. This can result in unidirectional tolerance, where donor lymphocytes are spared from attack by the host immune system, whereas host tissues are left vulnerable to attack by donor lymphocytes and their progeny (Figure 6.1). Incidence of TA-GVHD At present, TA-GHVD is an extremely rare phenomenon. In the United Kingdom, more than 4 million cellular blood components have been transfused since 1999 (Table 6.1). During that interval, there has been only one case of reported TA-GVHD. Similar data compiled by the US Food and Drug Administration (FDA) identified only three cases of fatal TA-GVHD in the United States from 25 to 213, during which time almost 15 million cellular blood components were transfused (Table 6.2). In both the United Kingdom and the United States, widespread use of blood component irradiation in at-risk populations has contributed to the low incidence of TA-GVHD. In Japan, there is substantially less HLA diversity than in the United States or the United Kingdom. In addition, Japan has a high rate of directed-donor blood collections where relatives donate Rossi s Principles of Transfusion Medicine, Fifth Edition. Edited by Toby L. Simon, Jeffrey McCullough, Edward L. Snyder, Bjarte G. Solheim, and Ronald G. Strauss. 2 John Wiley & Sons, Ltd. Published 2 by John Wiley & Sons, Ltd. 68

Chapter 6: Transfusion-associated graft-versus-host disease 681 Recipient Cell 9 HLA B37 Donor Cell Immune Attack on Recipient Cell Mediated by Detection by Donor Cell of non-self HLA type Figure 6.1 Unidirectional tolerance occurs when donor lymphocytes mediate an attack on host tissues while simultaneously being viewed as self by the host immune system. In this example, recipient cells expressing 9 and HLA B37 antigens are attacked by donor lymphocytes that do not express these antigens; however, donor-derived and expressing cells are not targeted by the recipient immune system because these antigens are also expressed by recipient cells. Scenario depicted similar to a case report by Benson et al. 49 Table 6.1 UK reports of cellular blood component infusions and TA-GVHD to the serious hazards of transfusion hemovigilance network, 1996 213 Year RBCs Transfused (UK) Platelets Transfused (UK) Reports of TA-GVHD (UK) 213 2,43,46 312,14 212 2,146,783 311,737 1 (Fatal) 211 2,2,137 31,628 21 2,18,781 246,962 29 2,29,153 266,312 28 2,4,256 258,419 27 2,235,638 255,474 26 2,3,152 259,654 25 2,428,934 258,528 24 2,67,41 264,539 23 2,678,98 251,741 21 22 2,679,925 251,451 2 21 2,76,37 25,259 1 (Fatal) 1999 2 2,737,572 249,622 1998 1999 2,386,475 259,25 4 (All fatal) 1997 1998 2,75, 33, 4 (All fatal) 1996 1997 2,43, 252, 4 (All fatal) Total 4,872,667 4,579,491 14 Universal leukodepletion introduced in 1999. Reference blood for other family members. 4,5 As a result, Japan has historically had a higher rate of TA-GVHD, and a large proportion of TA-GVHD case reports are published by Japanese authors. 4,5 Indeed, in Japan prior to the routine irradiation of blood components, TA-GVHD had a calculated expected incidence of 1 in 874 transfusions when donor and recipient were unrelated, and 1 in 12 Table 6.2 Reports of TA-GVHD to US FDA compared to annual estimates of transfusion of cellular blood components, 25 213 Year Number of RBCs Transfused (US) Platelets Transfused (US) Reports of Fatal TA-GVHD to FDA 213 NR NR 212 NR NR 211 13,785, 2,9, 1 21 NR NR 1 29 NR NR 28 15,14, 2,21, 27 NR NR 26 14,65, 1,731, 25 NR NR 1 Total 13,347, (est) Apheresis equivalent units. NR, Not reported; est, estimate.,763, (est) 3 34 14 35 36 37 38 39 4 41 42 43 44 21 45 2 19 18, 46, 47, 48 Reference when donor and recipient were a mother child pair. 4 Routine irradiation of cellular blood components was introduced in Japan in 1998, and there have been no published reports of TA-GVHD in Japan between 1999 and 213. 2 Similar scenarios are found in other countries where there is substantially less HLA diversity among the donor recipient population. Clinical scenarios associated with TA-GVHD Patients without recognized immunodeficiency syndromes Prior to the widespread irradiation of cellular blood components in Japan, the rate of TA-GVHD in Japan was higher than in Western Europe or the United States. The Japanese medical literature describes numerous cases of TA-GVHD in patients without a recognized immunodeficiency. 6 Uchida et al. reported that, among 66 confirmed cases of TA-GVHD in Japan from 1992 to 1999, 65 of the patients were not considered by the study authors to be immunosuppressed. 2 The majority of these patients received transfusions either during the treatment of solid tumors or for surgical or traumatic bleeding episodes. 2 Similarly, Juji et al. reported 96 cases of TA-GVHD among immunocompetent Japanese undergoing cardiac surgery between 1981 and 1986. 7 There are several factors that appear to play a role in the pathogenesis of TA-GVHD among patients without recognized immunodeficiency syndromes. One contributing factor is likely the relative HLA homogeneity in Japan, where many of the cases were reported. A study of 655 Japanese found the frequency of the most common HLA haplotype to be 7.5%, and the second most common HLA haplotype had a frequency of 5%. In contrast, the same study found the frequency of the most frequent HLA haplotype among US Caucasians to be only 4%, and the most common HLA haplotype among Italians was identified in only 2.2% of the population. 4 It is likely that the lack of HLA diversity among the Japanese population resulted in unidirectional tolerance more frequently in Japan than in other parts of the world, helping to explain the historically high levels of TA-GVHD in Japan prior to widespread irradiation of cellular blood components. However, the calculated incidence of TA-GVHD based on HLA similarity is much lower than the actual incidence of TA-GVHD, 1,8 indicating that a lack of HLA diversity is likely only one of many factors that influence the pathogenesis of TA-GVHD. Another factor that may contribute to TA-GVHD in some patients is trauma or major surgery, particularly cardiac surgery. 9 Although the mechanism of immune suppression, if any, contributing to TA-GVHD in these patient populations is not known, it has been reported that hospitalized patients, compared to healthy volunteers, are less likely to generate antibodies after exposure to

682 Section V: Part II: Other hazards allogeneic, minor blood group antigens via transfusion. 1 Consequently, it is possible that although hospitalization and surgery help to prevent alloimmunization, they simultaneously increase the risk of developing TA-GVHD. This hypothesis may also help explain the reported relatively high (1%) incidence of TA-MC seen after transfusion following a traumatic injury. 3 Besides cardiac surgery and HLA similarity between donor and recipient, other factors that have been associated with TA-GVHD in immunocompetent individuals have also been described, including transfusion of recently collected (<72 hours old) blood, 6 use of blood collected from first- or second-degree relatives, 6 and use of nonirradiated cellular blood products. 11 These factors likely enhance the probability of developing TA-GVHD by either enhancing the viability or dose of transfused lymphocytes (e.g., using fresh or non-leukoreduced or non-irradiated blood components) or increasing the likelihood of HLA similarity between donor and recipient (e.g., using blood from close family relations). A murine model of TA-GVHD has been described. 1 TA-GVHD in immunosuppressed patients Although cases of TA-GVHD are reported among patients without recognized immunodeficiency, many more reported cases involve patients who are profoundly immunosuppressed. 8 Among immunosuppressed patients, those considered at highest risk for the development of TA-GVHD include patients with severe T-cell immunodeficiency syndromes (e.g., severe combined immunodeficiency or DiGeorge syndrome), patients undergoing allogeneic or autologous bone marrow transplant, patients diagnosed with Hodgkin s lymphoma or aplastic anemia on immunosuppressive therapy, neonates, a fetus receiving intrauterine transfusions, and patients being treated with purine analogs (fludarabine, cladribine, or deoxycoformicin) or alemtuzumab (anti-cd52). 8,12,13 Although rare cases of TA-GVHD have been reported in patients after organ transplantation, undergoing treatment for solid tumors, or with either non-hodgkin s lymphoma or acute leukemia (without stem cell transplantation), the risk is generally considered to be lower compared to the first groups listed above. 12,13 No cases of TA- GVHD attributed only to immunodeficiency caused by HIV/AIDS (in the absence of other conditions listed above) have been reported in the medical literature to date. 12,13 National guidelines from the United Kingdom and Australia address the importance of ensuring that all cellular blood products used in high-risk settings are appropriately irradiated. 12,13 In a recent case report in 211 in the United Kingdom, two intrauterine transfusions were administered to a fetus (hemoglobin4.4g/dl)at21weeksgestationwhowasanemicduetoa maternal parvovirus infection. The transfusions were performed using a total of 33 ml of non-leukoreduced, nonirradiated blood that had been collected from the mother. 14,15 Although cellular blood components (including whole blood) intended for intrauterine transfusions are generally leukoreduced and irradiated in the United Kingdom, these product modifications were not made in this case due to the emergent need for the transfusions. At 32 weeks gestation, the fetus was delivered hydropic and pancytopenic. Two months after birth, a bone marrow biopsy revealed an aplastic marrow, and maternal engraftment was detected by chimerism studies. HLA typing performed on the mother found her to be HLA homozygous and showed unidirectional tolerance for her child. The neonate was diagnosed with TA-GVHD and died despite attempted allogeneic stem cell transplantation using stem cells collected from the mother. Diagnosis of TA-GVHD The most common signs and symptoms of TA-GVHD are fever, erythema, pancytopenia, bone marrow aplasia, diarrhea, and hepatitis; these generally occur within 1 2 weeks of transfusion but can be seen up to 3 days after transfusion. 2,5 The case fatality rate for TA-GVHD approaches 1%. 2,14, 21 The diagnosis of TA-GVHD requires a high degree of clinical suspicion, particularly given the relatively long latency period between transfusion and the development of symptoms (up to 3 days). In addition, if patients are critically ill at the time of their transfusion, it may be difficult to differentiate the clinical signs of TA-GVHD from their underlying illness. For these reasons, TA-GVHD may be underdiagnosed. 22 Nonetheless, a diagnosis of TA-GVHD should be considered in any patient with fever, erythema, neutropenia, diarrhea, and hepatitis within 3 days of a transfusion with nonirradiated cellular blood products (whole blood, RBCs, granulocytes, or platelets). It is notable that reports of TA-GVHD have never been attributed to transfusions with plasma, cryoprecipitate, factor concentrates, albumin, intravenous immunoglobulin, or previously frozen, deglycerolized RBCs. This is presumably due to the absence of sufficient viable donor lymphocytes in these products. 12 If TA-GVHD is suspected clinically, donor lymphocytes can be differentiated from host lymphocytes by measuring differences in restriction fragment length polymorphisms or numbers of short tandem repeats between the donor and the host. These tests can be performed using molecular assays that are routinely utilized to detect donor recipient chimerism in patients who have undergone allogeneic stem cell transplantation. 22 One strategy is to biopsy both affected and unaffected patient tissues and to compare the results to samples obtained from the blood donor (if available). 12 In older reports, detection of the Y chromosome was used to diagnose TA-GVHD resulting from a blood transfusion from a male donor to a female recipient. 23 Today, this approach is considered to be relatively insensitive in most circumstances, and would be of no use in cases of TA-GVHD suspected in male recipients, in patients who have undergone a sex-mismatched stem cell transplant, or in cases involving transfusion of a blood component collected from a female donor. Prevention of TA-GVHD Although the introduction of universal leukoreduction is associated temporally with a reduction in the reported incidence of TA- GVHD, cases of TA-GVHD have been reported in patients receiving leukoreduced (but nonirradiated) cellular blood transfusions. 24 In addition, the minimum dose of lymphocytes required to cause TA-GVHD in humans is not precisely known, and it may be influenced by factors that are not likely to be fully known prior to transfusion. These factors include the degree of HLA match between donor and recipient, the viability of the remaining transfused lymphocytes, and the degree of immunosuppression of the recipient. Consequently, leukoreduction alone is not considered to be sufficient prophylaxis against TA-GVHD; irradiation of cellular blood components is the only widely recognized method to prevent TA-GVHD in all cellular blood components. 12

Chapter 6: Transfusion-associated graft-versus-host disease 683 In the United States, in order to render lymphocytes contained in RBCs, platelets, granulocytes, or whole blood incapable of engraftment, it is an AABB Standard that for blood component irradiation, 25 Gy must be directed at the center of the blood component being irradiated, with a minimum of 15 Gy at any part of the bag. 25 Of note, standards in the United Kingdom require a minimum dose of 25 Gy, with no more than 5 Gy delivered to any portion of the bag. 12 Special, radiation-sensitive labels are used to verify and permanently document that a blood product was irradiated. The expiration date of irradiated RBCs is shortened to 28 days from the date of irradiation, or the product s original expiration, whichever comes first. 25 In contrast, platelet component expiration is not affected by irradiation. Blood products that are inadvertently irradiated more than once, or at a dose not in accordance with standards, usually need to be discarded, unless the medical director of the facility determines otherwise. It must be noted that bone marrow, peripheral blood stem cells, or donor lymphocytes infused as part of a hematopoietic stem cell transplant program must never be irradiated. Most blood banks or blood centers use 137 Cs, 6 Co, or X-rays as a source of ionizing radiation to provide the required dose of radiation. 26 In order to remove sources of ionizing radiation from hospital blood banks or blood centers that could be used for domestic terrorism, the US government is reviewing the possibility of eliminating irradiators that use 137 Cs or 6 Co and replacing them with X-ray-based irradiators. In the future, γ irradiation may be one of several acceptable ways to prevent TA-GVHD. Pathogen inactivation systems using amotosalen 27,28 or riboflavin 29,3 and ultraviolet (UV) light have shown promise in inactivating lymphocytes and potentially preventing TA-GVHD. At present, however, pathogen inactivation systems are not available for use with RBCs, whole blood, or granulocytes and are not widely used in the United States for prevention of TA- GVHD in platelets. This is an area that may rapidly change in the future, given recent (214) regulatory action in the United States licensing amotosalen/uv-a light systems for pathogen reduction of fresh frozen plasma (FFP) and platelets. Special tags that are sensitive to UV light can be used to label usints of plasma or platelets that have been pathogen inactivated using amotosalen and UV light. Due to the rarity of cases of TA-GVHD, and the limited availability of irradiation in hospitals in some rural areas of the United States, there is not universal consensus on the specific medical conditions that require the use of irradiated cellular blood products. Some of the most common indications for irradiation are summarized in Table 6.3. In some areas of the world where cellular blood product irradiation is not universal, patients with TA-GVHD risk factors are occasionally transfused with nonirradiated blood. 31 Fortunately, the incidence of TA-GVHD is still very low among patients with risk factors who should have received irradiated blood. For example, in the United Kingdom between 26 and 21, there were 389 instances where patients inadvertently received nonirradiated cellular blood components (when irradiation was indicated). This cohort included 8 patients undergoing purine analog therapy, 68 patients with lymphoma (including Hodgkin s lymphoma), and 44 patients undergoing stem cell transplant. None of these patients developed TA-GVHD as a consequence of their transfusion, although the reason for this lack of negative outcomes is unclear. Possible explanations include lack of HLA similarity between donors and recipients, or decreased lymphocyte viability due to the storage time of the blood component before transfusion. Regardless, if a patient at risk for TA-GVHD is transfused with a nonirradiated cellular blood component, they should be monitored for signs of TA-GVHD for 3 days. Table 6.3 Stratification of risk for development of TA-GVHD based on medical condition, component infused, and medication exposures Highest Risk Association Lower-Risk Association No Known Risk Medical Conditions Medical Conditions Medical Conditions -Stem cell transplant -Acute leukemia -HIV/AIDS -Aplastic anemia -Neonatal status -Solid organ transplantation -Solid tumors -Congenital humoral immunodeficiencies -Intrauterine status -Non-Hodgkin s lymphoma -Hodgkin s lymphoma -Severe cellular immunodeficiency syndromes -T cell malignancies -Patients undergoing trauma resuscitations or cardiac surgery Blood Components Blood Components -Nonirradiated whole blood -Plasma -Nonirradiated RBCs -Clotting factor concentrates -Nonirradiated platelets -Cryoprecipitate -Nonirradiated granulocytes -Albumin -Nonirradiated cellular components used for intrauterine transfusions -Nonirradiated fresh (<72 hours from collection) cellular blood components -Intravenous immunoglobulin -Irradiated whole blood -Irradiated RBCs -Previously frozen, deglycerolized RBCs -Nonirradiated cellular components collected from first- or second- degree relatives, or in transfusion within population with limited HLA diversity (e.g., Japan) -Purine antagonists (e.g., clofarabine) -Alemtuzumab (anti-cd52) -Irradiated platelets -Irradiated granulocytes -Freeze-dried plasma Medications Medications Medications -Purine analogs (e.g., fludarabine, cladribine, and deoxycoformicin) Other cytotoxic or immunomodulatory agents (e.g., ATG or rituximab) Noncytotoxic, nonimmunomodulatory agents (e.g., antibiotics)

684 Section V: Part II: Other hazards Treatment of TA-GVHD There are only rare reports of patients surviving TA-GVHD. In one case, recovery was attributed to treatment with OKT3 and cyclosporin A. 32 Another case of atypical TA-GVHD resolved spontaneously, although the patient had a maculopapular rash, which is not classic for TA-GVHD. 33 However, overall, one of the distinguishing characteristics of TA-GVHD, compared to post bone marrow transplant GVHD, is that TA-GVHD does not usually respond to immunosuppressive therapy. 1 Unfortunately, treatment is supportive and the case fatality rate approaches 1%. Conclusion TA-GVHD is a rare but almost uniformly fatal consequence of transfusion with cellular blood components. Although the incidence of TA-GVHD in the United States, the United Kingdom, and Japan has become very low in the past 1 15 years, there are still sporadic case reports. Therefore, vigilance in terms of both avoidance of unnecessary transfusions and irradiation of blood components given to high-risk patients who are susceptible to TA-GVHD must continually be borne in mind. Key references A full reference list for this chapter is available at: http://www.wiley.com/go/simon/ transfusion 2 Uchida S, Tadokoro K, Takahashi M, Yahagi H, Satake M, Juji T. Analysis of 66 patients definitive with transfusion-associated graft-versus-host disease and the effect of universal irradiation of blood. Transfus Med 213 Dec;23(6):4 22. 4 Ohto H, Yasuda H, Noguchi M, Abe R. Risk of transfusion-associated graft-versushost disease as a result of directed donations from relatives. Transfusion 1992 Sep;32(7):691 3. 12 Treleaven J, Gennery A, Marsh J, et al. Guidelines on the use of irradiated blood components prepared by the British Committee for Standards in Haematology blood transfusion task force. Br J Haematol 21 Jan;152(1):35 51. 13 Australian and New Zealand Society of Blood Transfusion (ANZSBT). Guidelines for prevention of transfusion-associated graft-versus-host disease (TA-GVHD). Sydney, Australia: ANZSBT, 211. 14 Bolton-Maggs PHB (Ed.), Watt A, Thomas D, Cohen H; Serious Hazards of Transfusion (SHOT) Steering Group. The 212 annual SHOT report. Manchester, UK: SHOT, 213.