Experts’ considerations on HLA‐haploidentical stem cell transplantation

Recently, novel strategies to control graft‐versus‐host disease and facilitate engraftment have allowed an increasing number of human leukocyte antigen (HLA)‐haploidentical hematopoietic stem cell transplantation (haploHSCT) to be performed. A meeting was convened to review the biological rationale and the clinical results of various T‐cell‐depleted (TCD) and T‐cell‐replete (TCR) HLA‐haploidentical ‘transplant platforms’. The objective of the meeting was to promote discussion and consent among leading researchers in the field on three main crucial issues for haploHSCT: (i) eligibility criteria, (ii) choice of the most suitable donor, and (iii) choice of the most appropriate transplant platform. The experts in attendance agreed that a patient who is eligible for an allogeneic transplant and lacks an HLA‐identical sibling or an HLA‐matched unrelated donor should be considered for an alternative donor transplant. Together with the experience of the individual center, the most important decision criteria in choosing an alternative donor source should be the rapidity of transplantation so as to avoid disease relapse/progression. The choice of the mismatched donor should be driven by younger age, ABO blood group compatibility, and Cytomegalovirus status. If a TCD transplant is planned, NK‐alloreactive donors and/or the mother should be preferred. Prospective comparative studies are needed to establish the relative efficacy of different transplant platforms. However, expertise in stem cell manipulation and in adoptive immunotherapy is essential if a TCD transplant platform is chosen.     

HLA-haploidentical nonmyeloablative stem cell transplantation: induction to tolerance without passing through mixed chimaerism

There are few reports of unmanipulated HLA-haploidentical nonmyeloablative stem cell transplantation (NST) using only pharmacological acute graft-vs.-host disease (GVHD) prophylaxis. We present here a successful case of unmanipulated HLA-haploidentical NST for mediastinal large B cell lymphoma that was resistant to autologous peripheral blood stem cell transplantation (PBSCT). The conditioning regimen consisted of fludarabine, busulfan and rabbit anti-T-lymphocyte globulin (ATG) in addition to rituximab. GVHD prophylaxis was performed using tacrolimus and methylprednisolone 1 mg/kg. The patient had rapid engraftment, with 100% donor chimaerism in the lineages of both T cells and granulocytes on day +12, but developed no GVHD clinically. The patient is still in complete remission past day +1020, with no sign of chronic GVHD without receiving immunosuppressive agents. HLA-haploidentical NST may be performed without utilizing mixed chimaerism.     

Rescue haploidentical peripheral blood stem cell transplantation for engraftment failure: a single‐centre case series

Graft failure affects approximately 5% of allogeneic stem cell transplants, with a poor prognosis. Salvage second allogeneic stem cell transplantation (alloSCT2) is limited by high rates of transplant‐related mortality from infection and graft‐versus‐host disease. We report on five adult patients receiving rescue alloSCT2 using haploidentical peripheral blood stem cells. All patients achieved neutrophil engraftment, two subsequently died from sepsis and disease relapse, respectively. Three patients remain alive up to 2 years post‐transplant. We suggest consideration of haploidentical alloSCT2 for patients with graft failure.     

High incidence of engraftment syndrome after haploidentical allogeneic stem cell transplantation

We determined the incidence, clinical manifestations, and outcomes of engraftment syndrome (ES) in haploidentical stem cell transplantation (SCT) recipients. We compared the incidence of ES between the patient group that received haploidentical SCT (n = 516) and the patient group that received HLA‐identical sibling SCT (n = 393). The transplantations were performed in the Peking University People's Hospital in the period between October 2001 and October 2012. The ES incidence data were collected retrospectively. Patients that presented non‐infectious fever or skin rash within the 24‐h window before or after the beginning of neutrophil recovery were diagnosed with ES in accordance with the Maiolino criteria. ES incidence in haploidentical SCT recipients (21.9%) was significantly higher than that in HLA‐identical sibling SCT recipients (2.0%; P < 0.001). Major symptoms included fever (119/121, 98.3%), skin rash (98/121, 81.0%), and diarrhea (51/121, 42.1%), with the median time of +10 d (range: 6–20 d). The median C‐reactive protein level of the ES group (99.0 mg/L; n = 13) was significantly higher than that of the non‐ES group (13.9 mg/L; n = 38; P < 0.001). Similarly, the results showed that the median C3 plasma concentration of the ES group (1.30 g/L) was higher than that of the non‐ES group (1.16 g/L, P = 0.003). ES was not associated with non‐relapse mortality or overall survival. High incidence of ES was observed in haploidentical SCT recipients; however, ES did not predict poor clinical outcomes.     

Non‐myeloablative haematopoietic stem cell transplantation for severe aplastic anaemia with various complications

We report a 20‐year‐old‐male with severe aplastic anaemia who was treated with nonmyeloablative haematopoietic stem cell transplantation (NSCT) from a sibling donor. As the patient presented with complications consisting of mental retardation, severe obesity, a bone fracture, and recurrent infections, we selected NSCT instead of a myeloablative regimen, to reduce regimen‐related toxicity (RRT). Conditioning therapy consisting of busulfan, fludarabine, antithymocyte globulin and FK506 was used to obtain immune suppression. RRT was limited and he is now in complete remission 19 months after NSCT. On day 91, he developed chronic graft‐vs.‐host disease; it was resolved by the combination of FK506, corticosteroids, and mycophenolate mofetil. Our experience contributes to the growing interest in NSCT as a modality for treating not only malignant haematological disorders associated with complications, but also nonmalignant haematological diseases.     

Transfer of Hexon‐ and Penton‐selected adenovirus‐specific T cells for refractory adenovirus infection after haploidentical stem cell transplantation

Adenovirus (HAdV) infections confer a high risk of morbidity and mortality for immunocompromised patients after stem cell transplantation (SCT). Treatment with standard antiviral drugs is of limited efficacy and associated with a high rate of adverse effects. HAdV‐specific T cells are crucial for sustained viral elimination and the efficacy of adoptive T‐cell therapy with donor‐derived HAdV‐specific T cells has been reported by several investigators. Here, we report our experience with the transfer of HAdV‐specific T cells specific for penton, which was recently identified as an immunodominant target of T cells, and hexon in a 14‐year‐old boy after T‐cell‐depleted haploidentical SCT for myelodysplastic syndrome (MDS). He developed severe HAdV‐associated enteritis complicated by acute graft‐versus‐host disease (GvHD). The patient received ten infusions of allogeneic HAdV‐specific T cells manufactured from the haploidentical stem cell donor using the CliniMacs Interferon‐γ (IFN‐γ) cytokine capture and immunomagnetic selection. Initially, T cells were generated against the immunodominant target hexon and in subsequent transfers dual antigen‐specific T cells against hexon and penton were applied. T‐cell transfers were scheduled individually tailored to current immunosuppressive treatment. Each transfer was followed by reduction of HAdV load in peripheral blood and clinical improvement. Importantly, T‐cell responses to both penton and hexon pools emerged in patient blood after repetitive transfers. Unfortunately, the patient experienced bacterial sepsis, and in this context, severe GvHD requiring intensive immunosuppression followed by secondary progression of HAdV infection. The patient succumbed to multiorgan failure 283 days after SCT. This case demonstrates the feasibility of HAdV‐specific T‐cell transfer even in the presence of immunosuppressive treatment. Targeting of multiple immunodominant viral proteins may prove valuable in patients with complicated HAdV infections.     

The evolution of T‐cell depletion in haploidentical stem‐cell transplantation

T‐cell depletion (TCD) can prevent the onset of graft‐versus‐host disease (GvHD) in animal models of bone marrow transplantation; this manipulation enabled the successful application in the 1980s of T‐cell depleted bone marrow (BM) for the treatment of babies with severe combined immune deficiency (SCID). However, in leukaemia patients, implementation of T‐cell depletion has been more difficult, especially due to high rate of graft‐rejection, leukaemia relapse and delayed immune reconstitution. These hurdles were gradually overcome by modifying the cell composition of the graft, and by reducing the toxicities associated with conditioning protocols. Although no ‘gold standard’ TCD method exists, T‐cell depletion in its modern forms could offer clinical benefit, even for patients with a matched sibling donor.     

Toxoplasma‐induced hemophagocytic lymphohistiocytosis after haploidentical allogeneic stem cell transplantation

Hemophagocytic lymphohistiocytosis (HLH) is a disorder of immune regulation, manifested by fever, pancytopenia, hyperferritiniemia, hypertriglyceridemia, and extensive hemophagocytosis involving the bone marrow and spleen. HLH can occur in adults with an underlying hematopoietic malignancy, or with systemic infections. HLH following hematopoietic stem cell transplantation (HSCT) is unusual, and the diagnosis may be challenging particularly because the diagnostic criteria in the HLH‐2004 guidelines overlap with common post‐transplant complications such as engraftment syndrome, graft‐vs‐host disease, and infections. HLH is commonly triggered by viral, bacterial and, less commonly, parasitic infections. Following HSCT, patients with latent Toxoplasma infection may develop systemic disease secondary to reactivation, and rarely this may lead to a HLH physiology, with a very high mortality rate. Herein we describe the successful management of disseminated toxoplasmosis associated with life‐threatening HLH using tocilizumab and antimicrobial therapy.     

HLA单倍体与全相合外周血干细胞移植后免疫功能重建与并发症的比较

目的 初探HLA单倍体相合与全相合异基因外周血干细胞移植(allo-PBSCT)后两组患者细胞免疫功能差异及其与主要并发症的关系.方法 选择2004年6月一2007年12月在新疆医科大学第一附属医院接受allo-PBSCT的67例患者,其中33例接受全相合,34例接受单倍体相合移植.采用间接免疫荧光法前瞻性检测移植前、后1、3、6、12及18个月两组患者的淋巴细胞亚群,同时检测100例正常对照.统计分析两组患者移植后免疫功能的重建情况及其与主要并发症的关系.结果 (1)67例患者与正常对照组比较,移植后1个月CD_3~+、CD_4~+、CD_4~+/CD_8~+、3个月CD_4~+、CD_4~+/CD_8~+及6个月CD_4~+均低于正常对照组,移植后3个月及6个月CD_4~+高于正常对照组.(2)单倍体与全相合患者移植后免疫功能比较差异无统计学意义(P>0.05).(3)单倍体移植重症感染与未感染患者免疫功能比较差异无统计学意义(P>O.05).(4)发生慢性移植物抗宿主病(cGVHD)与未发生cGVHD的两组患者间免疫功能比较差异均无统计学意义(P>0.05).(5)8例复发患者与未复发患者免疫功能差异无统计学意义(P>0.05).结论 应用含抗胸腺淋巴细胞球蛋白多种免疫抑制剂进行非体外去T细胞的PBSC单倍体移植,与常规方案进行HLA相合的PBSC移植相比,两组患者移植后的免疫功能重建总体无明显差异,移植后两组患者的重度感染率、白血病复发率及移植相关病死率差异也无统计学意义,提示单倍体移植方案是安全有效的.     

Nephrotic syndrome as a complication of chronic graft‐versus‐host disease after allogeneic haemopoietic stem cell transplantation

Nephrotic syndrome (NS) is a rare complication following allogeneic haemopoietic stem cell transplantation (allo‐HSCT), with limited current understanding of its pathogenesis. Here, we describe four cases of NS following allo‐HSCT diagnosed at our institutions to identify key clinical and pathological features. In addition, a PubMed search was performed to identify existing reports that were pooled together with our cases for analysis. NS occurred as a late complication following allo‐HSCT, with median onset 19.5 months after transplant (range: 3.9–84 months). The most common histopathology observed was membranous nephropathy; however, cases of minimal change disease have also been reported. There is a high incidence of prior extra‐renal graft‐versus‐host disease (GvHD), with all four of our cases and 82% of published cases having prior GvHD. Glucocorticosteroids are the most common treatment, with variable degrees of response. Responses to immunosuppression with calcineurin inhibitors and rituximab have been described in steroid‐refractory cases.     

Natural killer cells – new understanding of basic biology may lead to more effective allogeneic haematopoietic stem cell transplantation

The natural killer (NK) cells are part of the innate immune system and are responsible for initial defences in the surveillance against malignant cells and virally infected cells. In addition to direct cytotoxicity, cytokines produced by NK cells amplify the immune response and help control the neoplasm/pathogen. Several activating and inhibitory receptors responsible for NK cell activation are recently characterized and play a crucial role in tumour eradication. These include, but are not limited to, the killer immunoglobulin-like receptors, C-type lectin receptors and natural cytotoxicity receptors. The downstream signalling of some of these receptors is also characterized. The net balance in the sum of the signals generated by ligation of activating and inhibitory receptors determines the final outcome, cytotoxicity versus tolerance. NK cell-based immunotherapy can be successfully exploited in the haematopoietic stem cell transplantation for the treatment of haematological malignancies and has a potential to separate the beneficial graft versus leukaemia effect from, often dangerous, graft versus host disease. This article reviews the NK receptors important in NK-mediated cytotoxicity in allogeneic haematopoietic stem cell transplantation.     

Pericardial graft vs. host disease in a patient with myelodysplastic syndrome following peripheral blood stem cell transplantation

A patient with myelodysplastic syndrome developed pericardial effusion 20 month after allogenic peripheral blood stem cell transplantation. Sclerotic and erythematous skin lesions were observed over the face and extremities, and a diagnosis of chronic graft vs. host disease (GVHD) was made based on skin biopsy findings. Pericardial fluid contained numerous CD8+/HLA-DR+ lymphocytes, but no leukaemic cells. Tumour necrosis factor alpha (TNFalpha) and soluble Fas (sFas) levels were highly elevated in both the effusion and serum. The patient was treated with methylprednisolone and tacrolimus. Skin GVHD improved rapidly associated with resolution of pericardial effusion and reductions in cytokine levels. We concluded that pericardial effusion was due to pericarditis and was a manifestation of chronic GVHD in this patient, and that cytotoxic lymphocytes and specific cytokines played significant roles.     

Allogeneic haematopoietic cell transplantation after nonmyeloablative conditioning in patients with T‐cell and natural killer‐cell lymphomas

Patients with T‐cell and natural killer‐cell lymphomas have poor outcomes. This study examined the role of allogeneic haematopoietic cell transplantation (allo‐HCT) after nonmyeloablative conditioning in this setting. Seventeen patients with T‐cell lymphoma or NK‐cell lymphoma, including three patients in first complete remission, received allo‐HCT after 2 Gy total‐body irradiation and fludarabine. The median age was 57 (range, 18–73) years. The median number of prior therapies was 3 (range, 1–7), six patients (35%) had failed prior autologous HCT, and five patients (29%) had refractory disease at the time of allograft. Postgrafting immunosuppression was provided with mycophenolate mofetil with ciclosporin or tacrolimus. After a median follow‐up of 3·3 (range, 0·3–8·0) years among surviving patients, the estimated probabilities of 3‐year overall and progression‐free survival were 59% and 53%, respectively, while the estimated probabilities of non‐relapse mortality and relapse at 3 years were 19% and 26%, respectively. Sixty‐five percent of patients developed grades 2–4 acute graft‐versus‐host disease and 53% of patients developed chronic graft‐versus‐host disease. Allo‐HCT after nonmyeloablative conditioning is a promising salvage option for selected patients with T‐cell and NK‐cell lymphomas. These results suggest that graft‐versus‐T‐cell lymphoma activity is responsible for long‐term disease control.     

Treatment of postrenal transplantation lymphoproliferative disease manifesting as plasmacytoma with nonmyeloablative hematopoietic stem cell transplantation from the same kidney donor

Posttransplantation lymphoproliferative disease (PTLD) presenting as an Epstein-Barr-virus (EBV)-related nasal plasmacytoma developed in a renal-allograft recipient 13 years after transplantation. Systemic dissemination occurred despite immunosuppression withdrawal, surgery, irradiation, and chemotherapy. A nonmyeloablative hematopoietic-stem-cell-transplantation (HSCT) with peripheral blood HSC from the kidney donor was performed. With the onset of graft-versus-host disease, resolution of the systemic disease was demonstrated clinically and molecularly by serial quantification of plasma EBV-DNA. Isolated relapse occurred in the central nervous system (CNS), a known tumour sanctuary site, ultimately leading to death. Nonmyeloablative HSCT might be considered a cellular therapy for PTLD, but possible CNS relapse must be effectively tackled.     

Invasive zygomycosis in patients with graft‐versus‐host disease after allogeneic stem cell transplantation

M. Leithauser, C. Kahl, C. Aepinus, F. Prall, M. Maruschke, H. Riemer, D. Wolff, K. Jost, I. Hilgendorf, M. Freund, C. Junghanss. Invasive zygomycosis in patients with graft‐versus‐host disease after allogeneic stem cell transplantation
Transpl Infect Dis 2010: 12: 251–257. All rights reserved Abstract: Invasive mold infections are a threat to immunosuppressed patients such as patients with graft‐versus‐host disease (GVHD) after allogeneic stem cell transplantation (SCT). Up to 10% of SCT recipients develop invasive aspergillosis (IA). Invasive zygomycosis (IZ) may occur during treatment against IA. Here we report 4 SCT patients with GVHD diagnosed with IZ. All patients had received myeloablative hematopoietic SCT and developed chronic GVHD requiring systemic immunosuppression. Underlying diseases were acute lymphocytic leukemia (2), osteomyelofibrosis, and multiple myeloma. All patients had developed pulmonary infiltration that led to initiation of antifungal therapy. Treatment for IA was voriconazole, caspofungin, or itraconazole. Organs involved with zygomycosis were lung, nasal sinus, skin, and kidney. Treatment with liposomal amphotericin and posaconazole was initiated in all patients, and 2 patients also had surgical debridement as well. Despite intensive treatment, no patient survived. IZ is becoming more common in patients with GVHD on successful treatment for IA. Even non‐specific symptoms are suspicious in this group of patients and need to be evaluated by vigorous diagnostics. Despite effective antifungals and surgical intervention, the prognosis is grim in patients with active GVHD, as immunoreconstitution is mandatory for successful management.