Alexandra H. Filipovich

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.

Interleukin-2 receptor γ chain mutation results in X-linked severe combined immunodeficiency in humans

The interleukin-2 (IL-2) receptor gamma chain (IL-2R gamma) is a component of high and intermediate affinity IL-2 receptors that is required to achieve full ligand binding affinity and internalization. We have localized the IL-2R gamma gene to human chromosome Xq13. Genetic linkage analysis indicates that the IL-2R gamma gene and the locus for X-linked severe combined immunodeficiency (XSCID) appear to be at the same position. Moreover, we demonstrate that each of three unrelated patients with XSCID has a different mutation in his IL-2R gamma gene resulting in a different premature stop codon and predicted C-terminal truncation. These data establish that XSCID is associated with mutations of the IL-2R gamma gene product. Since XSCID is characterized by absent or markedly reduced numbers of T cells, our findings imply that IL-2R gamma plays a vital role in thymic maturation of T cells. These results also have important implications for prenatal and postnatal diagnosis, carrier female detection, and gene therapy for XSCID.

Analysis of 462 Transplantations from Unrelated Donors Facilitated by the National Marrow Donor Program

BACKGROUND AND METHODS Allogeneic bone marrow transplantation is curative in a substantial number of patients with hematologic cancers, marrow-failure disorders, immunodeficiency syndromes, and certain metabolic diseases. Unfortunately, only 25 to 30 percent of potential recipients have HLA-identical siblings who can act as donors. In 1986 the National Marrow Donor Program was created in the United States to facilitate the finding and procurement of suitable marrow from unrelated donors for patients lacking related donors. RESULTS During the first four years of the program, 462 patients with acquired and congenital lymphohematopoietic disorders or metabolic diseases received marrow transplants from unrelated donors. The probability of engraftment by 100 days after transplantation was 94 percent, although 8 percent of patients later had secondary graft failure. The probability of grade II, III, or IV acute graft-versus-host disease was 64 percent, and the probability of chronic graft-versus-host disease at one year was 55 percent. The rate of disease-free survival at two years among patients with leukemia and good prognostic factors was 40 percent and among patients at higher risk, 19 percent. Twenty-nine percent of the patients with aplastic anemia were alive at two years, and the rate of two-year disease-free survival among patients with myelodysplasia was 18 percent. For patients with congenital immunologic or nonimmunologic disorders, the probability of survival was 52 percent. CONCLUSIONS The National Marrow Donor Program has benefited a substantial number of patients in need of marrow transplants from closely HLA-matched unrelated donors and has facilitated the recruitment of unrelated donors into the donor pool and the access to suitable marrow.

How I treat hemophagocytic lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation, occurring as either a familial disorder or a sporadic condition, in association with a variety of triggers. This immune dysregulatory disorder is prominently associated with cytopenias and a unique combination of clinical signs and symptoms of extreme inflammation. Prompt initiation of immunochemotherapy is essential for survival, but timely diagnosis may be challenging because of the rarity of HLH, its variable presentation, and the time required to perform diagnostic testing. Therapy is complicated by dynamic clinical course, high risk of treatment-related morbidity, and disease recurrence. Here, we review the clinical manifestations and patterns of HLH and describe our approach to the diagnosis and therapy for this elusive and potentially lethal condition.

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].

New Malignant Diseases After Allogeneic Marrow Transplantation for Childhood Acute Leukemia

PURPOSE To determine the incidence of and risk factors for second malignancies after allogeneic bone marrow transplantation (BMT) for childhood leukemia. PATIENTS AND METHODS We studied a cohort of 3, 182 children diagnosed with acute leukemia before the age of 17 years who received allogeneic BMT between 1964 and 1992 at 235 centers. Observed second cancers were compared with expected cancers in an age- and sex-matched general population. Risks factors were evaluated using Poisson regression. RESULTS Twenty-five solid tumors and 20 posttransplant lymphoproliferative disorders (PTLDs) were observed compared with 1.0 case expected (P <.001). Cumulative risk of solid cancers increased sharply to 11.0% (95% confidence interval, 2.3% to 19.8%) at 15 years and was highest among children at ages younger than 5 years at transplantation. Thyroid and brain cancers (n = 14) accounted for most of the strong age trend; many of these patients received cranial irradiation before BMT. Multivariate analyses showed increased solid tumor risks associated with high-dose total-body irradiation (relative risk [RR] = 3.1) and younger age at transplantation (RR = 3.7), whereas chronic graft-versus-host disease was associated with a decreased risk (RR = 0.2). Risk factors for PTLD included chronic graft-versus-host disease (RR = 6.5), unrelated or HLA-disparate related donor (RR = 7. 5), T-cell-depleted graft (RR = 4.8), and antithymocyte globulin therapy (RR = 3.1). CONCLUSION Long-term survivors of BMT for childhood leukemia have an increased risk of solid cancers and PTLDs, related to both transplant therapy and treatment given before BMT. Transplant recipients, especially those given radiation, should be monitored closely for second cancers.

Risk Factors For Acute Graft-versus-host Disease In Histocompatible Donor Bone Marrow Transplantation

We have analyzed factors associated with acute graft-versus-host disease following allogeneic bone marrow transplantation in 469 patients with histocompatible sibling donors between 1979 and 1987. Overall, 46±5% (95% confidence interval) developed clinical grade II-IV acute GVHD following transplantation. In univariate analysis, patient or donor age ≥18 years was significantly associated with increased GVHD risks (≥18, 63± 6% grade II-IV GVHD vs. <18,27±6%, P<.0001), without incremental risk in older adults. Univariate analysis showed that donor:recipient sex match and female: female transplants were associated with less-frequent GVHD. More frequent GVHD was associated with chronic myelogenous leukemia, cytomegalovirus seropositivity, and prior donor alloimmunity (pregnancy or transfusion). Additionally, the allele HLA-A26 was associated with increased risk of GVHD (72%, P=.005) while HLA-DR3 was associated with less GVHD (31%, P=.03). Stepwise multivariate analysis confirmed the increased GVHD risks associated with older recipient age, HLA-A26 and donor:recipient gender (not female: female) and the protective effect of HLA-DR3. Similar results were found using the different analytic technique of recursive partition analysis, which identified within the adult population the lowest GVHD risk in female recipients with nonalloimmunized female donors (20%), while other gender combinations had 68% acute GVHD, regardless of donor alloimmunity. In children (<18 years), lower GVHD risk accompanied donor:recipient sex-matched (18%) versus mismatched (33%) BMT. Clinical trials undertaken to lessen the hazards of GVHD must be designed with appropriate attention to these reproducibly identified clinical variables associated with different GVHD risks.

Transplantation Outcomes for Severe Combined Immunodeficiency, 2000–2009

BACKGROUND The Primary Immune Deficiency Treatment Consortium was formed to analyze the results of hematopoietic-cell transplantation in children with severe combined immunodeficiency (SCID) and other primary immunodeficiencies. Factors associated with a good transplantation outcome need to be identified in order to design safer and more effective curative therapy, particularly for children with SCID diagnosed at birth. METHODS We collected data retrospectively from 240 infants with SCID who had received transplants at 25 centers during a 10-year period (2000 through 2009). RESULTS Survival at 5 years, freedom from immunoglobulin substitution, and CD3+ T-cell and IgA recovery were more likely among recipients of grafts from matched sibling donors than among recipients of grafts from alternative donors. However, the survival rate was high regardless of donor type among infants who received transplants at 3.5 months of age or younger (94%) and among older infants without prior infection (90%) or with infection that had resolved (82%). Among actively infected infants without a matched sibling donor, survival was best among recipients of haploidentical T-cell-depleted transplants in the absence of any pretransplantation conditioning. Among survivors, reduced-intensity or myeloablative pretransplantation conditioning was associated with an increased likelihood of a CD3+ T-cell count of more than 1000 per cubic millimeter, freedom from immunoglobulin substitution, and IgA recovery but did not significantly affect CD4+ T-cell recovery or recovery of phytohemagglutinin-induced T-cell proliferation. The genetic subtype of SCID affected the quality of CD3+ T-cell recovery but not survival. CONCLUSIONS Transplants from donors other than matched siblings were associated with excellent survival among infants with SCID identified before the onset of infection. All available graft sources are expected to lead to excellent survival among asymptomatic infants. (Funded by the National Institute of Allergy and Infectious Diseases and others.).

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.

Hypomorphic mutations in PRF1, MUNC13-4, and STXBP2 are associated with adult-onset familial HLH

Familial hemophagocytic lymphohistiocytosis (HLH) is a rare primary immunodeficiency disorder characterized by defects in cell-mediated cytotoxicity that results in fever, hepatosplenomegaly, and cytopenias. Familial HLH is well recognized in children but rarely diagnosed in adults. We conducted a retrospective review of genetic and immunologic test results in patients who developed HLH in adulthood. Included in our study were 1531 patients with a clinical diagnosis of HLH; 175 patients were 18 years or older. Missense and splice-site sequence variants in PRF1, MUNC13-4, and STXBP2 were found in 25 (14%) of the adult patients. The A91V-PRF1 genotype was found in 12 of these patients (48%). The preponderance of hypomorphic mutations in familial HLH-causing genes correlates with the later-onset clinical symptoms and the more indolent course in adult patients. We conclude that late-onset familial HLH occurs more commonly than was suspected previously.