R. Maarten Egeler

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. Pediatr Blood Cancer 2007;48:124–131.

Contemporary classification of histiocytic disorders

Pathologists and pediatric hematologist/ oncologists of the World Health Organizations Committee on Histiocytic/Reticulum Cell Proliferations and the Reclassification Working Group of the Histiocyte Society present a classification of the histiocytic disorders that primarily affect children. Nosology, based on the lineage of lesional cells and biological behavior, is related to the ontogeny of histiocytes (macrophages and dendritic cells of the immune system). Dendritic cell-related disorders of varied biological behavior are dominated by Langerhans cell histiocytosis, but separate secondary proliferations of dendritic cells must be differentiated. Juvenile xanthogranuloma represents a disorder of dermal dendrocytes, another dendritic cell of skin. The hemophagocytic syndromes are the most common of the macrophage-related disorders of varied biological behavior. Guidelines for distinguishing the exceedingly rare malignant diseases of histiocytes from large cell lymphomas through the use of a battery of special studies are provided.

HLH‐94: A treatment protocol for hemophagocytic lymphohistiocytosis

In January 1995, the Hemophagocytic Lymphohistiocytosis (HLH) Study Group opened its first international treatment study dedicated to the hemophagocytic lymphohistiocytoses. The main intention of the study protocol is to offer affected children therapy with a wellestablished chemotherapeutic regimen (epipodophyllotoxin and corticosteroids) in combinationwith a newer approach, immunotherapy with cyclosporin A. Subsequent bone marrow transplantation (BMT) is recommended to all children with an available donor. The purpose of this communication is to describe this approach to management, that intends to prolong survival and increase the cure rate for children throughout the world with this highly lethal disease [1].

Langerhans cell histiocytosis

The first major stride toward understanding LCH was taken when ultrastructural studies identified the proliferating cells as part of the Langerhans (dendritic) cell system. Another step forward was the definition of the morphologic, immunohistochemical, and clinical criteria needed for the diagnosis of LCH. Meanwhile, modern imaging studies have disclosed lesions that were not previously visible, especially those in the brain and the pituitary gland. These advantages have had a major impact on clinical management by making it possible to compare data from different institutions and to centralize coherent clinical and therapeutic data. Moreover, the agreement concerning diagnostic criteria provides a solid foundation for current clinical trials and for laboratory research regarding the possible roles of the immune system, clonality, and cytokines in the etiology of LCH.

Spectrum of perforin gene mutations in familial hemophagocytic lymphohistiocytosis.

Familial hemophagocytic lymphohistiocytosis (FHL) is an autosomal recessive disease of early childhood characterized by nonmalignant accumulation and multivisceral infiltration of activated T lymphocytes and histiocytes (macrophages). Cytotoxic T and natural killer (NK) cell activity is markedly reduced or absent in these patients, and mutations in a lytic granule constituent, perforin, were recently identified in a number of FHL individuals. Here, we report a comprehensive survey of 34 additional patients with FHL for mutations in the coding region of the perforin gene and the relative frequency of perforin mutations in FHL. Perforin mutations were identified in 7 of the 34 families investigated. Six children were homozygous for the mutations, and one patient was a compound heterozygote. Four novel mutations were detected: one nonsense, two missense, and one deletion of one amino acid. In four families, a previously reported mutation at codon 374, causing a premature stop codon, was identified, and, therefore, this is the most common perforin mutation identified so far in FHL patients. We found perforin mutations in 20% of all FHL patients investigated (7/34), with a somewhat higher prevalence, approximately 30% (6/20), in children whose parents originated from Turkey. No other correlation between the type of mutation and the phenotype of the patients was evident from the present study. Our combined results from mutational analysis of 34 families and linkage analysis of a subset of consanguineous families indicate that perforin mutations account for 20%-40% of the FHL cases and the FHL 1 locus on chromosome 9 for approximately 10%, whereas the major part of the FHL cases are caused by mutations in not-yet-identified genes.

Chemoimmunotherapy for hemophagocytic lymphohistiocytosis: long-term results of the HLH-94 treatment protocol

Hemophagocytic lymphohistiocytosis (HLH) used to have a dismal prognosis. We report the final results of HLH-94, the largest prospective diagnostic/therapeutic HLH study so far. The treatment includes immunosuppressive and cytotoxic therapy aiming at clinical remission, followed by HSCT in patients with familial, persistent, or recurrent disease. Altogether, 249 patients fulfilled inclusion criteria and started HLH-94 therapy (July 1994-December 2003); 227 (91%) were followed-up for ≥ 5 years. At 6.2 years median follow-up, estimated 5-year probability of survival was 54% ± 6%. Seventy-two patients (29%) died before HSCT, 64 within 1 year, 97% of whom had active disease. In 124 patients who underwent HSCT, 5-year survival was 66 ± 8%; tendency to increased survival (P = .064) in patients with nonactive disease at HSCT. Patients with familial disease had a 5-year survival of 50% ± 13%; none survived without HSCT. Patients deceased during the first 2 months more often had jaundice, edema, and elevated creatinine. Forty-nine patients (20%) were alive without signs of HLH activity and off-therapy > 1-year without HSCT; they presented at older age (P < .001), were more often female (P = .011), and less often had CNS disease (P < .001) or hepatomegaly (P = .007). To conclude, HLH-94 chemoimmunotherapy has considerably improved outcome in HLH. Collaborative efforts are needed to further reduce early mortality, HSCT-related mortality, and neurologic late effects.

Assessment of Parental Psychological Stress in Pediatric Cancer: A Review

OBJECTIVES We present an overview of the literature between 1997 and 2007 on parental stress reactions following the diagnosis of childhood cancer and we evaluate methodological strengths and weaknesses of the studies. METHODS PubMed, PsychInfo, and Cinahl databases were used. Sixty-seven were included in the review. RESULTS The conceptualization of parental stress and timing of assessment varies considerably between the studies, which makes comparison difficult. Most emotional stress reactions are seen around the time of diagnosis, with mothers reporting more symptoms than fathers. As a group, parents seem relatively resilient, although a subset of parents reports continuing stress even up to 5 years or more postdiagnosis. CONCLUSIONS The authors recommend clear definitions of parental stress, fixed points in time to assess parental stress, and an approach that highlights both parental strengths and weaknesses. Improved assessment can contribute to tailoring psychological care to those parents most in need.

Chemotherapeutic adjuvant treatment for osteosarcoma: Where do we stand?

AIM Since the introduction of chemotherapy, survival in localised high-grade osteosarcoma has improved considerably. However, there is still no worldwide consensus on a standard chemotherapy approach. In this systematic review evidence for effectiveness of each single drug and the role of response guided salvage treatment of adjuvant chemotherapy are addressed, whereas in a meta-analysis the number of drugs in current protocols is considered. METHODS A systematic literature search for clinical studies in localised high-grade osteosarcoma was undertaken, including both randomised and non-randomised trials. Historical clinical studies from the pre-chemotherapy era were included for comparison purposes. RESULTS Nine historical studies showed a long-term survival of 16% after only local treatment. Fifty single agent phase II studies showed high response rates for adriamycin (A, 43%), ifosfamide (Ifo, 33%), methotrexate (M, 32%), cisplatin (P, 26%) but only 4% for etposide (E). In 19 neo-adjuvant studies the mean 5-year event free survival (EFS) was 48% for 2-drug regimens and 58% for ⩾3 drug regimens, with a 5-year overall survival (OAS) of 62% and 70%, respectively. Meta-analysis showed that ⩾3 drug regimens including methotrexate plus adriamycin plus cisplatin (plus ifosfamide) (MAP(Ifo)) had significant better outcome (EFS: HR=0.701 (95% confidence interval [95% CI]: 0.615-0.799); OAS: HR=0.792 (95% CI: 0.677-0.926) than 2-drug regimens, but there was no significant difference between MAP and MAPIfo (or plus etoposide). Salvage of poor responders by changing drugs, or intensifying treatment postoperatively has not proven to be useful in this analysis. CONCLUSION Meta-analysis in patients with localised high-grade osteosarcoma shows that 3-drug regimens, for example MAP are the most efficacious drug regimens.

Haematopoietic stem cell transplantation in haemophagocytic lymphohistiocytosis.

Haemophagocytic lymphohistiocytosis (HLH) poses major therapeutic challenges, and the primary inherited form, familial haemophagocytic lymphohistiocytosis (FHL), is usually fatal. We evaluated, including Cox regression analysis, survival in 86 children (29 familial) that received HLH‐94‐therapy (etoposide, dexamethasone, ciclosporin) followed by allogeneic stem cell transplantation (SCT) between 1995 and 2000. The overall estimated 3‐year‐survival post‐SCT was 64% [confidence interval (CI) = ±10%] (n = 86); 71 ± 18% in those patients with a matched related donor (MRD, n = 24), 70 ± 16% with a matched unrelated donor (MUD, n = 33), 50 ± 24% with a family haploidentical donor (haploidentical, n = 16), and 54 ± 27% with a mismatched unrelated donor (MMUD, n = 13). After adjustment for potential confounding factors, estimated odds ratios (OR) for mortality were 1·93 (CI =0·61–6·19) for MUD, 3·31 (1·02–10·76) for haploidentical, and 3·01 (0·91–9·97) for MMUD, compared with MRD. In children with active disease after 2‐months of therapy (n = 43) the OR was 2·75 (1·26–5·99), compared with inactive disease (n = 43). In children with active disease at SCT (n = 37), the OR was 1·80 (0·80–4·06) compared with inactive disease (n = 49), after adjustment for disease activity at 2‐months. Mortality was predominantly transplant‐related. Most HLH patients survived SCT using MRD or MUD, and survival with partially mismatched donors was also acceptable. Patients that responded well to initial pretransplant‐induction therapy fared best, but some persisting HLH activity should not automatically preclude performing SCT.

Revised classification of histiocytoses and neoplasms of the macrophage-dendritic cell lineages

The histiocytoses are rare disorders characterized by the accumulation of macrophage, dendritic cell, or monocyte-derived cells in various tissues and organs of children and adults. More than 100 different subtypes have been described, with a wide range of clinical manifestations, presentations, and histologies. Since the first classification in 1987, a number of new findings regarding the cellular origins, molecular pathology, and clinical features of histiocytic disorders have been identified. We propose herein a revision of the classification of histiocytoses based on histology, phenotype, molecular alterations, and clinical and imaging characteristics. This revised classification system consists of 5 groups of diseases: (1) Langerhans-related, (2) cutaneous and mucocutaneous, and (3) malignant histiocytoses as well as (4) Rosai-Dorfman disease and (5) hemophagocytic lymphohistiocytosis and macrophage activation syndrome. Herein, we provide guidelines and recommendations for diagnoses of these disorders.