The outcome of hematopoietic stem cell transplantation in Korean children with hemophagocytic lymphohistiocytosis

Yoon HS, Im HJ, Moon HN, Lee JH, Kim H‐J, Yoo KH, Sung KW, Koo HH, Kang HJ, Shin HY, Ahn HS, Cho B, Kim HK, Lyu CJ, Lee MJ, Kook H, Hwang TJ, Seo JJ. The outcome of hematopoietic stem cell transplantation in Korean children with hemophagocytic lymphohistiocytosis.
Pediatr Transplantation 2010: 14:735–740. © 2010 John Wiley & Sons A/S. Abstract: Chemoimmunotherapy‐based treatments have improved the survival of patients with HLH, but outcomes of the patients are still unsatisfactory. We report here the outcome of Korean children with HLH who underwent HSCT, which was analyzed from the data of a nation‐wide HLH registry. Retrospective nation‐wide data recruitment for the pediatric HLH patients diagnosed between 1996 and 2008 was carried out by the Histiocytosis Working Party of the Korean Society of Hematology. Nineteen patients who received HSCT among the total of 148 enrolled children with HLH were analyzed for the transplant‐related variables and events. The probability of five‐yr survival after HSCT was 73.3% with a median follow‐up of 57. Two months compared to 54.3% for the patients who were treated with chemoimmunotherapy only (p = 0.05). The reasons for HSCT were active disease after eight wk of initial treatment (n = 9), relapsed disease (n = 5), and FHL (n = 5). Fourteen patients are currently alive without disease after HSCT, four patients died of treatment‐related events (infection in two and graft failure in two) at early post‐transplant period, and one patient died of relapse at one yr post transplantation. The survival of patients who were transplanted because of active disease after eight wk of initial treatment was worse compared to those patients who had inactive state at that time (60.6% vs. 100%, respectively, p = 0.06). Of the four patients who received transplants using cord blood, three died of graft failure (n = 2) and relapse (n = 1). The five‐yr probability of survival after HSCT according to the donor type was 85.7% for the MRDs (n = 6), 87.5% for the MUDs (n = 8), and 40% for the MMUDs (n = 5) (p = 0.03). Other variables such as age, CNS involvement at the time of diagnosis, the etiology of HLH (familial or secondary), and the conditioning regimens had no influence on the five‐yr OS of the HLH patients who underwent HSCT. HSCT improved the survival of the patients who had familial, relapsed, or severe and persistent SHLH in the Korean nation‐wide HLH registry. Although numbers were small, these results are similar to other reports in the literature. The disease state after initial treatment, the stem cell source of the transplant, and the donor type were the important prognostic factors that affected the OS of the HLH patients who underwent HSCT.     

Post‐hematopoietic stem cell transplant hemophagocytic lymphohistiocytosis or an impostor: Case report and review of literature

HLH occurring after HSCT is a relatively rare disease. Many conditions may mimic or trigger HLH in post‐HSCT period (eg, cytokine release syndrome, engraftment syndrome, graft rejection/failure, acute graft‐vs‐host disease, infections systemic inflammatory response syndrome/sepsis, and thrombotic microangiopathy). Moreover, this period is usually marked by febrile illness, cytopenia, and a “cytokine storm” leading to elevation of inflammatory biomarkers like ferritin and sCD25. These parameters overlap with the diagnostic criteria for HLH. Such confounding factors make the management of post‐HSCT HLH quite challenging. We illustrate this critical issue with case report of a patient who was diagnosed with HLH after allogeneic HSCT for tAML. He received MP and CsA for HLH but VP‐16 was not administered due to fear of severe myelosuppression. Fortunately, he responded well to treatment and remains in remission to date. We recommend caution while using HLH‐94/HLH‐2004 guidelines for the diagnosis and management of post‐HSCT HLH. In this article, we pinpoint these issues with a brief review of all the pediatric cases and clinical studies of post‐HSCT HLH along with a critical evaluation of its various diagnostic criteria. Finally, based on the limitations of current diagnostic criteria, we suggest a need for formulating disease‐specific diagnostic criteria for post‐HSCT HLH.     

Life-threatening hemophagocytic syndromes: Current outcomes with hematopoietic stem cell transplantation

Abstract:  Life-threatening hemophagocytic syndromes represent a subset of genetic disorders of inflammation. Many are rapidly lethal and can only be definitively treated at the present time with allogeneic hematopoietic stem cell transplantation (HSCT). In this report, current results with allogeneic transplantation for Hemophagocytic Lymphohistiocytosis (HLH) are described. HLH typically presents symptomatically during infancy and early childhood and can be identified by a constellation of numerous physical findings and laboratory tests indicative of overwhelming inflammation. The majority of patients with familial HLH lack natural killer (NK) cell function; in approximately 50% of cases the specific underlying genetic cause can now be discerned. Effective treatment consists of initial combination therapy with proapoptotic chemotherapy (typically etoposide) and anti-inflammatory therapies (principally steroids) in addition to aggressive supportive care, followed by allogeneic HSCT from the best available donor. Over the past 25 yr, through collaborative worldwide efforts, survival of children with HLH and related disorders has improved from 5% at 1 yr after diagnosis to greater than 50% 3–5 yr after diagnosis.     

HLH-2004方案诊断治疗小儿噬血细胞综合征结果分析

目的 了解我国小儿噬血细胞综合征(HLH)的发病情况和治疗效果,并开展HLH的穿孔素(perforin)基因研究.方法 研究对象为符合国际组织细胞协会HLH-2004诊断标准的18例患儿,分析患儿起病时及治疗后的临床资料.用流式细胞仪和基因测序法检测患儿的穿孔素基因.结果 流式细胞仪检测发现1例患儿的穿孔素在CD8+T细胞和NK细胞中的表达几乎完全缺如,而且基因测序发现该患儿的穿孔素基因存在错义突变(G47C),确诊为原发性HLH.14例接受HLH-2004治疗,随访时间2周～39个月,临床缓解4例,复发4例,持续活动4例,失访2例.共死亡7例.结论 HLH-2004是诊断和治疗小儿HLH的有效方案,提高生存率需积极开展造血干细胞移植.为鉴别原发性和继发性HLH应进行相关基因检测.     

Salvage therapy for refractory hemophagocytic lymphohistiocytosis: A review of the published experience

Hemophagocytic lymphohistioytosis (HLH) is a severe, life‐threatening hyperinflammatory disorder that requires prompt diagnosis and treatment. Approximately, 25–50% of patients with HLH fail to achieve remission with established regimens that include dexamethasone and etoposide, or methylprednisolone and antithymocyte globulin (ATG). Some of these patients may require salvage or alternative therapeutic approaches. There is a paucity of literature regarding effective salvage therapies for patients with refractory HLH. In this review, we summarize the published experience of four therapeutics reported for using at least two patients with HLH refractory to dexamethasone and etoposide or methylprednisolone and ATG.     

Allogeneic hematopoietic stem cell transplantation is associated with cure and durable remission of late‐onset primary isolated central nervous system hemophagocytic lymphohistiocytosis

Primary isolated CNS presentation of HLH is exceedingly rare and typically associated with significant morbidity and mortality. We describe an adolescent patient with late‐onset, primary isolated CNS HLH and a compound heterozygous PRF1 mutation (c50delT (p.L17 fs); c.1229G>C (p.R410P)), not previously reported with this phenotype. He was successfully treated with allogeneic HSCT following a reduced‐intensity conditioning regimen, despite a high pre‐HSCT comorbidity index. Two years after transplant, he is alive and in disease remission. While patients with systemic HLH and active CNS disease have relatively poorer outcomes, a high index of suspicion may aid with early diagnosis of primary isolated CNS HLH; prompt treatment with HSCT may be associated with improved cure and durable remission of this rare disease.     

Hematopoietic stem cell transplantation in children with Griscelli syndrome: A single‐center experience

GS2 is a rare autosomal recessive disease characterized by hypopigmentation, variable immunodeficiency with HLH. HSCT is the only curative treatment for GS2. We analyzed the outcome of 10 children with GS2 who underwent HSCT at our center between October 1997 and September 2013. The median age of the patients at transplant was 13.5 months (range, 6‐58 months). All of the patients developed HLH before HSCT and received HLH 94 or HLH 2004 protocols. Donors were HLA‐identical relatives in 8 patients, HLA‐mismatched relatives in 2 patients. Engraftment was achieved in all except one patient. None of the patients developed acute GVHD. Chronic GVHD occurred in one and veno‐occlusive disease occurred in four patients. Eight of the patients are under remission without any neurologic sequelae—median time of disease‐free survival is 92.4 months. The present study shows successful transplant outcome without long‐term neurologic sequelae in patients with GS2 who underwent HSCT from HLA‐related donors.     

Hemophagocytic lymphohistiocytosis in systemic mastocytosis treated with allogeneic bone marrow transplant: A case report

Systemic mastocytosis is a rare entity in pediatrics, usually associated with mutations in the c‐KIT gene. We describe a Caucasian female who presented with severe systemic mastocytosis with food allergies requiring prolonged total parenteral nutrition. Her course was further complicated by the onset of hemophagocytic lymphohistiocytosis, which responded poorly to conventional chemotherapy. She underwent an allogeneic hematopoietic stem cell transplant that resulted in resolution of all symptoms related to systemic mastocytosis and hemophagocytic lymphohistiocytosis. She is now disease‐free and without any complications two years after the transplant.     

Rotavirus‐associated hemophagocytic lymphohistiocytosis (HLH) after hematopoietic stem cell transplantation for familial HLH

Hemophagocytic lymphohistiocytosis (HLH) is a life‐threatening disorder of immune regulation. HLH consists of two forms: familial and acquired, the latter which occurs in association with infection, malignancy, rheumatic disease and acquired immune deficiency. Herein, we report a case of acquired HLH in a child who had received allogeneic hematopoietic stem cell transplantation for familial HLH with UNC13D mutation. Based on microbiology, only rotavirus was identified as a possible organism triggering HLH. The patient's fulminant clinical course included acute respiratory failure, a sepsis‐like pattern, disseminated intravascular coagulopathy, and rhabdomyolysis, leading to multiorgan failure and death from septic shock.     

HLH-2004: Diagnostic and therapeutic guidelines for hemophagocytic lymphohistiocytosis

In HLH-94, the first prospective international treatment study for hemophagocytic lymphohistiocytosis (HLH), diagnosis was based on five criteria (fever, splenomegaly, bicytopenia, hypertriglyceridemia and/or hypofibrinogenemia, and hemophagocytosis). In HLH-2004 three additional criteria are introduced; low/absent NK-cell-activity, hyperferritinemia, and high-soluble interleukin-2-receptor levels. Altogether five of these eight criteria must be fulfilled, unless family history or molecular diagnosis is consistent with HLH. HLH-2004 chemo-immunotherapy includes etoposide, dexamethasone, cyclosporine A upfront and, in selected patients, intrathecal therapy with methotrexate and corticosteroids. Subsequent hematopoietic stem cell transplantation (HSCT) is recommended for patients with familial disease or molecular diagnosis, and patients with severe and persistent, or reactivated, disease. In order to hopefully further improve diagnosis, therapy and biological understanding, participation in HLH studies is encouraged.     

Incidence and treatment of hemophagocytic lymphohistiocytosis in hospitalized children with Ehrlichia infection

We report a large cohort of pediatric patients with human monocytic ehrlichiosis (HME), enabling an estimated incidence of secondary hemophagocytic lymphohistiocytosis (HLH) in hospitalized children with HME. Among 49 children with PCR‐confirmed Ehrlichia infection, 8 (16%) met current criteria for HLH. Those with HLH had more significant hematologic abnormalities and longer durations from symptom onset to admission and definitive anti‐infective therapy. Among these eight, three received chemotherapy plus doxycycline, one of whom died; the other five were treated with doxycycline without chemotherapy, and all survived without HLH recurrence. Our findings demonstrate that antimicrobial therapy alone can successfully resolve Ehrlichia‐associated HLH.     

Development of secondary T‐cell acute lymphoblastic leukemia in a child with hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a severe life‐threatening disorder, characterized by hyperactivation of macrophages. A 12‐year‐old female was referred to our center; the diagnosis of HLH was made for the patient and immunosuppressive regimen was started. After a 2‐year follow‐up, the patient developed secondary T‐cell acute lymphoblastic leukemia (T‐ALL), confirmed by flow cytometric studies. Treatment was started based on T‐ALL protocol, but the patient died because of relapse and sepsis. This case highlights the issue of secondary malignancy following HLH and demonstrates the need for continued follow‐up in such patients. Pediatr Blood Cancer. 2010;55:725–726. © 2010 Wiley‐Liss, Inc.     

Secondary hemophagocytic lymphohistiocytosis in pediatric patients: a single center experience and factors that influenced patient prognosis

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening syndrome of excessive immune activation. Secondary HLH syndrome develops as a complication of infection, drugs, rheumatologic conditions, or malignancy. The main objectives of this work were to identify the etiology of secondary HLH and prognostic factors associated with mortality. Patients diagnosed with secondary HLH, between January 2011 and December 2016, were retrospectively included in this study. We analyzed clinical and laboratory findings as well as prognostic factors from 24 pediatric patients diagnosed with secondary HLH. The mean age of patients at the time of diagnosis was 79.9?±?68.7?months (range: 2–202) and 54.2% of the patients were male. The most frequent HLH-2004 criterion was fever (100%). Underlying triggers of HLH were as follows: 13 (54.1%) infections, juvenile idiopathic arthritis in 5 patients (20.8%), drugs in 3 patients (12.5%), malignancies in 2 (0.8%), Kawasaki disease in 1 (0.4%) patient, and 1 (0.4%) with unknown triggers. The median time of diagnosis was 3?days (1–67?days). Overall, the mortality rate was 20.8%. In our logistic regression model, factors associated with mortality were decreased albumin levels (OR1?=?2.3[1.48–3.43]) and etoposide usage (OR2?=?1.22 [1.14–1.89]). The patient’s 30-day survival was inferior among patients whose albumin level was 2?g/dL or less compared to those over 2?g/dL. Increased awareness of the underlying condition is critical in HLH patients. Our study emphasizes the prognostic significance of albumin level.