Diagnosis and treatment of juvenile myelomonocytic leukemia

Juvenile myelomonocytic leukemia (JMML) is a rare myelodysplastic/myeloproliferative disorder that occurs during infancy and early childhood; this disorder is characterized by hypersensitivity of the myeloid progenitor cells to granulocyte–macrophage colony‐stimulating factor in vitro. JMML usually involves somatic and/or germline mutations in the genes of the RAS pathway, including PTPN11, NRAS, KRAS, NF1, and CBL, in the leukemic cells. Almost all patients with JMML experience an aggressive clinical course, and hematopoietic stem cell transplantation (HSCT) is the only curative treatment. A certain proportion of patients with somatic NRAS and germline mutations in CBL, however, have spontaneous resolution. A suitable treatment after diagnosis and conditioning regimen prior to HSCT are yet to be determined, but several clinical trials have been initiated throughout the world to develop suitable pre‐ or post‐allogeneic HSCT treatments and new targeted therapies that are less toxic, to improve patient outcome.     

Low toxicity of a conditioning with 8-Gy total body irradiation, fludarabine and cyclophosphamide as preparative regimen for allogeneic hematopoietic stem cell transplantation in pediatric hematological malignancies

Abstract:  We here report the efficacy and toxicity of a conditioning regimen with fractionated 8-Gy TBI, fludarabine, and cyclophosphamide in allogeneic HSCT for pediatric hematological malignancies. Among 22 children who received related or unrelated HSCT, nine were transplanted with refractory disease and/or from HLA two or more loci-mismatched family donors. None of the patients developed graft failure. The Seattle grading system revealed that 18 patients had no RRT, and the remaining patients had grade I gastrointestinal toxicity alone. The estimated overall survival and leukemia-free survival at two yr were 57.1% and 48.0%, respectively, in 10 patients with acute lymphoblastic leukemia; 91.7% and 71.3%, respectively, in 12 patients with myeloid leukemia. The incidence of TRM was 4.8% at two yr. The rates of RRT above grade II and TRM in an 8-Gy TBI-containing regimen were significantly lower than the data of historical control patients who underwent 12-Gy TBI and cyclophosphamide with or without etoposide. The intermediate-dose TBI-based conditioning regimen may confer successful engraftment combined with minimized RRT, although its efficacy should be further evaluated.     

Pharmacokinetics of high-dose etoposide administered in combination with fractionated total-body irradiation as conditioning for allogeneic hematopoietic stem cell transplantation in children with acute lymphoblastic leukemia

Etoposide (VP-16) is one of the most widely used antitumor agents in pediatric oncology as well as chemotherapeutic agents used in conditioning regimen prior to allo-HSCT for childhood ALL. This study included 21 children with ALL who underwent allo-HSCT after conditioning with FTBI and high-dose of VP-16 (60 mg/kg) given intravenously as single four-h infusion on day -3 (n=2) or day -4 (n=19) prior to allo-HSCT. Blood samples were collected at defined time intervals until 120 h elapsed from the end of infusion. VP-16 plasma concentrations were determined using validated HPLC method. Three-compartment model was assumed for assessing PK parameters of VP-16. The median value of VP-16 C(max) measured at the end of infusion was 188.0 μg/mL (range 148.0-407.0 μg/mL). Out of 21 studied children, VP-16 was still detectable in 17 patients 72 h (median concentration 0.31 μg/mL) and in eight patients 96 h (median concentration 0.31 μg/mL) after the end of infusion. VP-16 concentration 96 h after the end of infusion was positively correlated with VP-16 AUC and negatively correlated with VP-16 CL normalized to body weight.     

Fludarabine based reduced intensity conditioning regimens in children undergoing allogeneic stem cell transplantation for severe aplastic anemia

Fourteen children with a median age of 9.8 yr with SAA (10 males, four females) underwent related HLA identical allogeneic stem cell transplantation using Flu, Cy +/- ATG between 2004 and 2006. GVHD prophylaxis consisted of cyclosporine +/- mini methotrexate. Graft source included PBSCs (seven) or BM (seven). One patient expired <7 days post-transplant, while 12 (85.7%) patients engrafted with median neutrophil and platelet engraftment times of 13.8 and 14.5 days each. One patient had primary graft failure and expired on Day +27. Acute GVHD was seen in 25% of evaluable patients while limited chronic GVHD was seen in 33%. At a mean follow-up of 18 months, 12 patients (85.7%) are alive and well. Compared with a historical cohort of 12 children transplanted using Cy/ATG, there was faster engraftment (13.8 vs. 16.4 days; p = 0.002) with lower rejection rates (7.1 vs. 36.3%; p = 0.133) and improved event free (85.7 vs. 54.5%; p = 0.177) and overall survival (85.7 vs. 63.6%; p = 0.350). Flu with Cy +/- ATG reduces rejection and improves overall and event free survival in children with aplastic anemia.     

幼年粒单细胞白血病造血干细胞移植疗效初探

目的探讨造血干细胞移植治疗幼年粒单细胞白血病(JMML)的疗效。方法 5例JMML患儿接受无关供者脐血造血干细胞移植治疗。预处理均采用Bu/Cy+Mel+ATG方案:马利兰(0.8～1.0)mg/kg,每6小时1次共用16次(-8d～-5d);环磷酰胺60mg/(kg·d)用2d(-4～-3d);马法兰140mg/m2用1次(-2d):抗胸腺细胞球蛋白2.5mg/(kg·d)连用4d(-4～-1d)。GVHD预防采用CsA+MP±MMF。结果 5例成功植入,3例复发,1例复发后死于卡氏肺囊虫肺炎,1例死于CMV感染相关间质性肺炎,1例长期无病存活。结论 5例JMML移植初步治疗结果不满意,移植失败主要原因为白血病复发。为减少复发,今后需进一步改进移植方法 ,包括选择其他供体、改进GVHD预防方案。     

Rapid progression of metastatic osteosarcoma after initiation of a reduced-intensity conditioning regimen with immunosuppressive fludarabine

Indications for RIST have not been established in patients with solid tumors. In this study, we performed RIST as immunotherapy in a 13-yr-old girl with intractable but not progressive osteosarcoma, which originated from the inter-costal region. Carcinomatous pleurisy suddenly developed after the start of a conditioning regimen that included Flu and BUS. She died of respiratory failure on day +19 without signs of engraftment. This case suggests that unexpected acceleration of tumor growth may occur following RIST with immunosuppressive drugs before the development of a beneficial GVT effect.     

异基因造血干细胞移植治疗儿童慢性粒细胞性白血病的疗效分析

目的：研究异基因造血干细胞移植（allogeneic hematopoietic stem cell transplantation, allo-HSCT）治疗儿童慢性粒细胞性白血病（chronic myelogenous leukemia, CML）的治疗效果,寻找可能的影响因素,以期改善患者预后。方法：对接受allo-HSCT治疗的20例儿童CML患者,分别从年龄、性别、诊断至移植间隔时间、供受体HLA配型相合情况、移植时患儿疾病状态以及急慢性移植物抗宿主病（gost-v-host disease, GVHD）等多种因素进行疗效分析。结果：截止至随访日期,20例患者中,13例无病存活,7例死亡,其中4例死于急性重度GVHD,2例死于慢性GVHD及其并发症,1例死于移植后复发,3年总无病生存率为（64.6±1.1%）。单因素分析显示年龄是影响儿童CML治疗预后最重要的因素之一（P0.05）。多因素logistic回归分析也进一步证明仅年龄是影响预后的因素（P<0.01）。各种严重急慢性 GVHD是引起患者死亡最重要的原因。选择10位点全相合的供体进行移植治疗预后好。结论：allo-HSCT能有效治疗儿童CML,对于年龄≥10岁的CML患儿宜早期行allo-HSCT移植治疗,且尽可能选择10位点全相合的供体进行移植,积极防治GVHD,改善CML患儿移植治疗后的转归。     

Non‐total body irradiation myeloablative conditioning with intravenous busulfan and cyclophosphamide in hematopoietic stem cell transplantation for malignant infantile osteopetrosis

HSCT is the only curative treatment for MIOP. We prospectively investigated the outcome of HSCT using intravenous busulfan‐based conditioning regimen from 2008 to 2013. Nineteen patients (median age = 17 months) underwent transplantation from HLA‐matched related donors (n = 14), HLA‐haploidentical related donors (n = 2), partially matched cord blood donors (n = 2), and HLA‐matched unrelated donor (n = 1). Bone marrow (n = 9), peripheral blood (n = 8), and cord blood (n = 2) were used as stem cell sources. All but one patient demonstrated primary engraftment. Two patients experienced secondary graft failure. During the follow‐up period, three patients showed mixed chimerism (45%, 45%, and 70% of donor cells were engrafted in each one of these patients) but are disease free. Two‐yr OS and DFS were 84.2% and 73.7%, respectively. Improvement of visual acuity and partial reversal of mild conductive hearing loss occurred in two and four patients, respectively. The causes of death among three patients were infection, GvHD, and disease progression. In conclusion, due to major side effects of MIOP such as visual and hearing loss, early treatment using myeloablative conditioning without irradiation HSCT is suggested. The use of an HLA‐matched related donor seems to be highly successful in this regard. Also, according to results of our study, mixed chimerism may be sufficient to resolve symptoms of disease.     

异基因造血干细胞移植治疗儿童急性髓系白血病临床研究

目的评估应用异基因造血干细胞移植(allo-HSCT)治疗儿童急性髓系白血病(AML)的临床疗效及相关影响因素。方法回顾分析2002年1月至2017年11月49例确诊中、高危及复发AML行allo-HSCT患儿的临床资料,分析危险度分级、HLA分型、移植前状态、移植方式、干细胞来源及急慢性移植物抗宿主病(GVHD)等对allo-HSCT治疗效果的影响。结果 49例患儿中男35例、女14例,中位年龄9岁。三年总体存活率(OS)为(59.2±7.3)%,无白血病存活率(LFS)为(50.9±7.4)%。其中第1次缓解状态移植、非血缘移植、外周血干细胞移植、中危组移植的三年LFS分别为69.8%、69. 2%、73. 7%、65. 8%。19例死亡,分别为复发13例、严重感染5例、多器官衰竭1例。COX回归模型结果显示,急性GVHD是影响移植OS的独立危险因素(RR=3. 16,95%CI:1. 23～8. 09,P=0. 017),移植前状态为部分缓解及未缓解是影响移植LFS的独立危险因素(RR=4.76,95%CI:1.52～14.94,P=0.008;RR=5.28,95%CI:1.68～16.58,P=0.004)。结论移植前状态及急性GVHD是影响Allo-HSCT治疗儿童AML疗效的关键因素;白血病复发及感染是导致死亡的主要原因。     

Iron overload in survivors of childhood leukemia after allogeneic hematopoietic stem cell transplantation

Abstract:  Iron overload has not been studied extensively and prospectively in pediatric survivors of allogeneic hematopoietic stem cell transplantation (HSCT); therefore, we conducted a prospective long-term study of 133 survivors of childhood leukemia to assess the incidence of and risk factors for iron overload and to investigate its association with organ dysfunction. One yr after HSCT, the mean serum ferritin level was 1158 ng/mL (range, 22–3264 ng/mL), with 124 patients (93.2%) having a serum ferritin level that exceeded the upper limit of the normal range (110 ng/mL). Thereafter, the serum ferritin level declined over time. There was a positive correlation between the level of serum ferritin and that of total bilirubin (r   =   0.21, p < 0.001) and glutamate pyruvate transaminase (r   =   0.17, p < 0.001). A high concentration of serum ferritin was associated with low cardiac fractional shortening (r   = −0.15, p  =  0.047). In addition, patients with hypothyroidism and GH deficiency had a higher level of serum ferritin than those without (p < 0.02). We conclude that iron overload is common after HSCT and is associated with hepatic, cardiac, and endocrine dysfunction.     

造血干细胞移植治疗儿童白血病若干问题

该文涉及各类儿童造血干细胞移植(HSCT),如骨髓移植(BMT)、外周血造血干细胞移植(PBSCT)和脐血移植(UCBT)治疗白血病的优缺点及HSCT在儿童白血病治疗中的地位。绝大多数儿童白血病可通过正规联合化疗根治,仅少数(约20%)高危、难治及复发的白血病是异基因HSCT的适应证,无适合的同胞供体时,可选择HLA全相合非血缘相关BMT或PBSCT,UD-UCBT更适合于儿童患者。     

Bullous pemphigoid after allogeneic hematopoietic stem cell transplantation

Bullous pemphigoid (BP) is an autoimmune skin disorder characterized by subepidermal blisters due to deposit of autoantibody against dermal basement membrane protein. It has been reported that BP can occur after allogeneic hematopoietic stem cell transplantation (HSCT). We describe a patient with BP having autoantibody against BP180 after unrelated‐donor HSCT against T lymphoblastic leukemia. The patient was treated with steroid leading to complete resolution of BP, but T lymphoblastic leukemia progressed rapidly after steroid hormone treatment. Given that immunosuppressant may reduce graft‐versus‐tumor effect, immunomodulatory agents such as nicotinamide and tetracycline, erythromycin, and immunoglobulin may be appropriate as soon as typical blister lesions are seen after HSCT.     

Non-hematopoietic stem cell transplantation treatment of juvenile myelomonocytic leukemia: a retrospective analysis and definition of response criteria

BACKGROUND: Juvenile myelomonocytic leukemia (JMML) is a rare myeloproliferative disease of infancy. Allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative treatment modality, while the role of anti-leukemic therapy prior to HSCT is uncertain. A comparative evaluation of the efficacy of different clinical protocols and great variety of anti-neoplastic drugs applied pre-HSCT is hampered by the lack of uniform criteria of response. Classification schemas applied in other forms of leukemia are of little value, because in JMML therapy may result in divergent responses in solid organs compared to peripheral blood (PB). PROCEDURE: We therefore defined separate response criteria for white blood count (WBC), platelet count, liver size, and spleen size. We then retrospectively evaluated the efficacy of 129 treatment courses other than HSCT administered to 63 children with JMML. Treatment consisted of intensive therapy according to AML-type chemotherapy, maintenance-type combination therapy, and single agent therapy. To account for the variability observed in the natural course of disease, we also evaluated 32 episodes of "no therapy." RESULTS: Best responses within 3 months of initiation of therapy were highly variable for the four response criteria. In contrast to platelet count and liver size, there was a significant correlation between WBC or spleen size and therapy. Response rates for WBC and spleen size were best for purine analogs, etoposide, and cytarabine as single agents or for maintenance-type combination therapy. CONCLUSION: To rigorously test future therapeutic strategies in this rare disease an international consensus on the definition of response criteria will be helpful.     

Hematopoietic stem cell transplantation with reduced toxicity conditioning regimen in mitochondrial neurogastrointestinal encephalopathy syndrome

Background

Mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) is a rare autosomal recessive disorder due to mutations in the TYMP gene. Clinical findings are characterized by neurologic manifestations and severe gastrointestinal dysfunction. The syndrome is usually fatal, the most effective treatment appears to be hematopoietic stem cell transplantation (HSCT).

Procedure

In this retrospective study, we evaluated HSCT that was performed using a reduced toxicity myeloablative conditioning regimen in patients with MNGIE at our center.

Results

A total of six allogeneic transplant procedures were performed in four patients. Three patients had fully matched donors, and one patient had a haploidentical donor. Treosulfan-based myeloablative conditioning regimen was applied in five of six transplants. Bone marrow was used as a stem cell source. One patient is being followed up in the 4th year of posttransplant with full chimeric and without graft versus host disease (GVHD). One patient died of acute stage IV gastrointestinal system GVHD. Two patients underwent second transplantation due to engraftment failure, one of which was the patient who had a haploidentical transplant.

Conclusions

Treosulfan-based regimen is well tolerated, although engraftment failure with this conditioning regimen can be a significant problem. We share our haploidentical transplant experience, which will be the first reported case in the literature.