Favorable immune recovery and low rate of GvHD in children transplanted with partially T cell-depleted PBSC grafts.

Transplantation of peripheral blood stem cells (PBSC) from matched unrelated donors (MUD) is still associated with a significant risk for graft vs. host disease (GvHD), especially in pediatric patients receiving grafts from adult donors containing high amounts of T cells. Here, we present long-term follow-up results on 25 pediatric patients, (acute leukemia n = 15, NHL n = 3, CML n = 3, MDS n = 5), transplanted with CD34 or CD133 positively selected PBSC from MUDs supplemented with an add-back of 1 × 107/kg body weight (kgBW) unselected T cells resulting in a median T-cell depletion (TCD) of 1.97 log. A total of 24/25 (96%) patients had primary engraftment. Early T-cell recovery was significantly improved compared to patients receiving CD34-selected grafts without T-cell add-back and similar to patients receiving unmanipulated bone marrow. GvHD incidence was low with 8/4% aGvHD grade II/III, no grade IV and 13% limited cGvHD. In total, 16/25 (64%) patients are alive after a median follow-up of 10 years. Five-year event-free survival (EFS) was 68%, relapse probability 24% and transplantation-related mortality (TRM) 12%. Thus, in PBSC allotransplants from MUD, partial TCD with serotherapy and CSA/MTX prophylaxis, can effectively reduce GvHD without hampering engraftment and immune reconstitution.

Haploidentical Stem Cell Transplantation for Refractory/Relapsed Neuroblastoma.

Pediatric patients with refractory or relapsed metastatic neuroblastoma (NBL) have a poor prognosis despite autologous stem cell transplantation (SCT). Allogeneic SCT from a haploidentical donor has a remarkable alloreactive effect in patients with leukemia; thus, we evaluated this approach in children with very high-risk NBL. We analyzed data from 2 prospective phase I/II trials. A total of 26 patients with refractory (n = 5), metastatic relapsed (n = 20), or locally relapsed MYCN-positive (n = 1) NBL received a median of 17 × 106/kg T/B cell-depleted CD34+ stem cells with 68 × 103/kg residual T cells and 107 × 106/kg natural killer cells. The conditioning regimen comprised melphalan, fludarabine, thiotepa, OKT3, and a short course of mycophenolate mofetil post-transplantation. Engraftment occurred in 96% of the patients. Event-free survival and overall survival at 5 years were 19% and 23%, respectively. No transplantation-related mortality was observed, and the single death was due to progression/subsequent relapse. The median duration of follow-up was 8.1 years. Patients in complete remission before SCT had a significantly better prognosis than those with residual tumor load (P < .01). All patients with progressive disease before SCT relapsed within 1 year. Grade II and grade III acute graft-versus-host disease (GVHD) occurred in 31% and 12% of the patients, respectively. Chronic limited and extensive GVHD occurred in 28% and 10%, respectively. Our data indicate that haploidentical SCT is a feasible treatment option that can induce long-term remission in some patients with NBL with tolerable side effects, and may enable the development of further post-transplantation therapeutic strategies based on the donor-derived immune system.

Posaconazole plasma concentrations in pediatric patients receiving antifungal prophylaxis during neutropenia.

Invasive fungal infections are one of the major complications in pediatric patients during prolonged neutropenia after chemotherapy. Evaluation of the efficacy and safety of the triazole posaconazole in these patients is missing. This multicenter survey analyzed trough concentrations of 33 pediatric patients with a median age of 8 years during 108 neutropenic episodes who received prophylactic posaconazole oral suspension. A total of 172 posaconazole trough levels were determined to median 438 ng/ml (range 111-2011 ng/ml; mean 468 ± 244 ng/ml). Age and gender had no influence on posaconazole plasma levels. Posaconazole was not discontinued due to adverse events in any of the patients. Only hepatic parameters significantly increased beyond the upper normal limit to median values of ALT of 87 U/l (P < .0001), and AST of 67 U/l (P < .0001). One patient with a median posaconazole trough concentration of 306 ng/ml experienced an invasive fungal infection. In conclusion, posaconazole was effective, safe and feasible in 33 pediatric patients with neutropenia ≥5 days after chemotherapy. Median posaconazole plasma concentrations were approximately 1.6-fold lower than the recommended plasma level of 700 ng/ml. Larger patient cohorts are needed to evaluate these findings.

Reduction of Minimal Residual Disease in Pediatric B-lineage Acute Lymphoblastic Leukemia by an Fc-optimized CD19 Antibody.

Prognosis of primary refractory and relapsed pediatric B-lineage acute lymphoblastic leukemia (ALL) is very poor. Relapse rates significantly correlate with persistent minimal residual disease (MRD). In MRD, favorable effector-target ratios prevail and thus this situation might be optimally suited for immunotherapy with antibodies recruiting immunological effector cells. We here report on the generation, preclinical characterization and first clinical application in B-lineage ALL of an Fc-optimized CD19 antibody. This third-generation antibody (4G7SDIE) mediated enhanced antibody-dependent cellular cytotoxicity (ADCC) against leukemic blasts with effector cells from healthy volunteers and B-lineage ALL patients. The antibody was produced in a university-owned production unit and was applied on a compassionate use basis to 14 pediatric patients with refractory and relapsed B-lineage ALL at the stage of MRD. In 10/14 patients, MRD was reduced by ≥ 1 log or below the patient-individual detection limit, and 5/14 patients have achieved ongoing complete molecular remission with a median leukemia-free survival of 428 days. Two additional patients died in complete molecular remission due to complications not related to antibody therapy. Besides profound in vivo B-cell depletion, side effects were negligible. A clinical phase 1/2 study to further assess the therapeutic activity of 4G7SDIE is in preparation.

Treatment of graft failure with TNI-based reconditioning and haploidentical stem cells in paediatric patients.

Graft failure is a life-threatening complication after allogeneic haematopoietic stem cell transplantation (HSCT). We report a cohort of 19 consecutive patients (median age: 8·5 years) with acute leukaemias (n = 14) and non-malignant diseases (n = 5) who experienced graft failure after previous HSCT from matched (n = 3) or haploidentical donors (n = 16) between 2003 and 2012. After total nodal irradiation (TNI)-based reconditioning combined with fludarabine, thiotepa and anti-T cell serotherapy, all patients received T cell-depleted peripheral blood stem cell grafts from a second, haploidentical donor. Median time between graft failure and retransplantation was 14 d (range 7-40). Sustained engraftment (median: 10 d, range 9-32) and complete donor chimerism was observed in all evaluable patients. 5 patients additionally received donor lymphocyte infusions. Graft-versus-host disease (GvHD) grade II and III occurred in 1 patient each (22%); no GvHD grade IV was observed. 2 patients had transient chronic GvHD. The regimen was well tolerated with transient interstitial pneumonitis in one patient. Treatment-related mortality after one year was 11%. Event-free survival and overall survival 3 years after retransplantation were 63% and 68%. Thus, a TNI-based reconditioning regimen followed by transplantation of haploidentical stem cells is an option to rescue patients with graft failure within a short time span and with low toxicity.

DOCK8 deficiency: clinical and immunological phenotype and treatment options - a review of 136 patients.

Mutations in DOCK8 result in autosomal recessive Hyper-IgE syndrome with combined immunodeficiency (CID). However, the natural course of disease, long-term prognosis, and optimal therapeutic management have not yet been clearly defined. In an international retrospective survey of patients with DOCK8 mutations, focused on clinical presentation and therapeutic measures, a total of 136 patients with a median follow-up of 11.3 years (1.3-47.7) spanning 1693 patient years, were enrolled. Eczema, recurrent respiratory tract infections, allergies, abscesses, viral infections and mucocutaneous candidiasis were the most frequent clinical manifestations. Overall survival probability in this cohort [censored for hematopoietic stem cell transplantation (HSCT)] was 87 % at 10, 47 % at 20, and 33 % at 30 years of age, respectively. Event free survival was 44, 18 and 4 % at the same time points if events were defined as death, life-threatening infections, malignancy or cerebral complications such as CNS vasculitis or stroke. Malignancy was diagnosed in 23/136 (17 %) patients (11 hematological and 9 epithelial cancers, 5 other malignancies) at a median age of 12 years. Eight of these patients died from cancer. Severe, life-threatening infections were observed in 79/136 (58 %); severe non-infectious cerebral events occurred in 14/136 (10 %). Therapeutic measures included antiviral and antibacterial prophylaxis, immunoglobulin replacement and HSCT. This study provides a comprehensive evaluation of the clinical phenotype of DOCK8 deficiency in the largest cohort reported so far and demonstrates the severity of the disease with relatively poor prognosis. Early HSCT should be strongly considered as a potential curative measure.

Human leukocyte antigen DR surface expression on CD14+ monocytes during adverse events after hematopoietic stem cell transplantation.

The human leukocyte antigen DR surface expression on CD14+ monocytes reflects the degree to which these cells have been activated. Given the central role monocytes and macrophages play in the immune system, a decreased human leukocyte antigen DR expression on CD14+ monocytes results in a hallmark of altered immune status during systemic inflammatory response syndrome. We hypothesize that human leukocyte antigen DR expression might be similarly altered after hematopoietic stem cell transplantation and during post-transplant complications. Using flow cytometry, this study investigates the human leukocyte antigen DR surface expression of CD14+ monocytes in 30 pediatric and young adult patients up to 1 year after hematopoietic stem cell transplantation. Normal values were derived from a control group of healthy children, adolescents, and young adults. Human leukocyte antigen DR expression decreased significantly prior and during bacterial infection or sepsis. By contrast, human leukocyte antigen DR expression levels were elevated before and at the time of viremia. Human leukocyte antigen DR expression was also elevated during acute graft-versus-host disease. In contrast, the expression was reduced when patients had hepatic veno-occlusive disease. A significant decrease of human leukocyte antigen DR expression was associated with a relapse of the underlying disease and before death. Human leukocyte antigen DR expression on CD14+ monocytes appears to be a promising parameter that might allow identification of patients at risk after hematopoietic stem cell transplantation.

Phagocytic activity of monocytes, their subpopulations and granulocytes during post-transplant adverse events after hematopoietic stem cell transplantation.

Phagocytosis of granulocytes and monocytes presents a major mechanism that contributes to the clearance of pathogens and cell debris. We analyzed the phagocytic activity of the peripheral blood cell monocytes, three monocyte subpopulations and granulocytes before and up to one year after hematopoietic stem cell transplantation, as well as during transplant-related adverse events. 25 pediatric patients and young adults (median age of 11.0 years) with hemato-oncological malignancies and non malignancies were enrolled in the prospective study. Ingestion of fluorescence-labeled Escherichia coli bacteria was used to assess the phagocytic activity of monocytes and their subpopulations and granulocytes by means of flow cytometry in the patient group as well as in a control group (n=36). During sepsis, a significant increase of phagocytic activity of monocytes (P=0.0003) and a significant decrease of the phagocytic activity of granulocytes (P=0.0003) and the CD14+ CD16++ monocyte subpopulation (P=0.0020) occurred. At the onset of a veno-occlusive disease, a significant increase of phagocytic activity in the CD14++ CD16+ monocyte subpopulation (P=0.001) and a significant decrease in the phagocytic activity of the CD14++ CD16- monocyte subpopulation (P=0.0048) were observed. In conclusion, the phagocytic activity of monocytes, their subpopulations and granulocytes might be a useful and easy determinable parameter that enables identification of post-transplant complications after hematopoietic stem cell transplantation. The alterations of phagocytic activity contribute to the altered immune response that accompanies adverse events after hematopoietic stem cell transplantation.

Increase of suicide and accidental death after hematopoietic stem cell transplantation: a cohort study on behalf of the Late Effects Working Party of the European Group for Blood and Marrow Transplantation (EBMT).

BACKGROUND: Relapse and transplant-related complications are leading causes of mortality after hematopoietic stem cell transplantation (HSCT). Suicides and accidents have not been studied in these patients. This study sought to determine whether there is an excess of suicide and accidental deaths after HSCT, and to determine risk factors. METHODS: The incidence of suicidal and accidental death in patients after undergoing HSCT, standardized mortality ratio (SMR), and absolute excess risk (AER) of suicide and accidental deaths was determined, compared with the general European population. A case-control analysis was done to define factors associated with suicide and accidental deaths. Data were derived from the European Group for Blood and Marrow Transplantation Registry, including 294,922 patients who underwent autologous or allogeneic HSCT from 1980 to 2009. RESULTS: The 10-year cumulative incidence of suicide and accidental deaths was 101.8 and 55.6 per 100,000 patients, respectively. SMR and AER of suicide after HSCT were 2.12 (P < .001) and 10.91, higher than in the European general population for 100,000 deaths, respectively. SMR and AER of accidental death were 1.23 (P < .05) and 2.54, respectively. In the case-control study, relapses were more frequent among patients who committed suicide after autologous HSCT (37% versus 18%; P < .0001). Chronic graft-versus-host disease was higher among patients who committed suicide after allogeneic HSCT (64% versus 37%; P = .001). CONCLUSIONS: There is an excess of deaths due to suicide and accidents in patients after undergoing HSCT as compared with the European general population. Relapse was associated with more suicide and accidental deaths after autologous HSCT, and chronic graft-versus-host disease was associated with more deaths by suicide after allogeneic HSCT.

Analysis of posaconazole as oral antifungal prophylaxis in pediatric patients under 12 years of age following allogeneic stem cell transplantation.

BACKGROUND: Pediatric patients undergoing hematopoietic stem cell transplantation (HSCT) are at high risk of acquiring fungal infections. Antifungal prophylaxis shortly after transplantation is therefore indicated, but data for pediatric patients under 12 years of age are scarce. To address this issue, we retrospectively assessed the safety, feasibility, and initial efficacy of prophylactic posaconazole in children. METHODS: 60 consecutive pediatric patients with a median age of 6.0 years who underwent allogeneic HSCT between August 2007 and July 2010 received antifungal prophylaxis with posaconazole in the outpatient setting. 28 pediatric patients received an oral suspension at 5 mg/kg body weight b.i.d., and 32 pediatric patients received the suspension at 4 mg/kg body weight t.i.d. The observation period lasted from start of treatment with posaconazole until its termination (maximum of 200 days post-transplant). RESULTS: Pediatric patients who received posaconazole at 4 mg/kg body weight t.i.d. had a median trough level of 383 µg/L. Patients who received posaconazole at 5 mg/kg body weight b.i.d. had a median trough level of 134 µg/L. Both regimens were well tolerated without severe side effects. In addition, no proven or probable invasive mycosis was observed. CONCLUSION: Posaconazole was a well-tolerated, safe, and effective oral antifungal prophylaxis in pediatric patients who underwent high-dose chemotherapy and HSCT. Posaconazole at a dosage of 12 mg/kg body weight divided in three doses produced consistently higher morning trough levels than in patients who received posaconazole 5 mg/kg body weight b.i.d. Larger prospective trials are needed to obtain reliable guidelines for antifungal prophylaxis in children after HSCT.

Analyses from a centre of short- and long-term growth in Turner's syndrome on standard growth hormone doses confirm growth prediction algorithms and show normal IGF-I levels.

AIMS AND METHODS: Prediction algorithms suggest factors determining short- and long-term growth response to growth hormone (GH) in Turner's syndrome (TS). A total of 133 patients (group A; 53% with karyotype 45,X) completed 1 year of treatment and 77 patients (group B) reached adult height (AH) after >4 years on GH treatment. The patients were analysed for factors determining the outcomes, and in addition, the validity of published algorithms was tested. RESULTS: In group A [values are given as medians (10th-90th percentiles)], starting age was 9.4 (4.8-14) years, height was -3.2 (-4.4 to -1.9) SDS (Prader references), and GH dose was 38 (23-48) µg/kg/day. Observed height velocity was 7.7 (5.2-9.8) cm/years and was equal to the predicted height velocity. In group B, projected adult height (PAH) was 147.4 (139.5-154.8) cm. Total gain in height over PAH of 6.1 (2.0-12.6) cm was negatively correlated with height at start, but positively correlated with GH duration, first year Δheight SDS, or index of responsiveness. Observed AH was 153.5 (146.6-160.1) cm and predicted AH was 155.0 (147.4-161.0) cm, which is statistically not different. On GH <5% IGF-I levels were >2 SDS. CONCLUSIONS: The published prediction algorithms were found to be valid. If normal AH is to be reached at the lowest costs and risks, probably only TS children with a good growth potential and a high responsiveness to GH can be treated successfully with GH doses of <50 µg/kg/day.

Secondary autoimmune diseases occurring after HSCT for an autoimmune disease: a retrospective study of the EBMT Autoimmune Disease Working Party.

To specify the incidence and risk factors for secondary autoimmune diseases (ADs) after HSCT for a primary AD, we retrospectively analyzed AD patients treated by HSCT reported to EBMT from 1995 to 2009 with at least 1 secondary AD (cases) and those without (controls). After autologous HSCT, 29 of 347 patients developed at least 1 secondary AD within 21.9 (0.6-49) months and after allogeneic HSCT, 3 of 16 patients. The observed secondary ADs included: autoimmune hemolytic anemia (n = 3), acquired hemophilia (n = 3), autoimmune thrombocytopenia (n = 3), antiphospholipid syndrome (n = 2), thyroiditis (n = 12), blocking thyroid-stimulating hormone receptor antibody (n = 1), Graves disease (n = 2), myasthenia gravis (n = 1), rheumatoid arthritis (n = 2), sarcoidosis (n = 2), vasculitis (n = 1), psoriasis (n = 1), and psoriatic arthritis (n = 1). After autologous HSCT for primary AD, the cumulative incidence of secondary AD was 9.8% ± 2% at 5 years. Lupus erythematosus as primary AD, and antithymocyte globulin use plus CD34(+) graft selection were important risk factors for secondary AD by multivariate analysis. With a median follow-up of 6.2 (0.54-11) years after autologous HSCT, 26 of 29 patients with secondary AD were alive, 2 died during their secondary AD (antiphospholipid syndrome, hemophilia), and 1 death was HSCT-related. This European multicenter study underlines the need for careful management and follow-up for secondary AD after HSCT.

Long-term remission after first-line single-agent treatment with arsenic trioxide of relapsed acute promyelocytic leukemia in an 8-year-old boy.

Arsenic trioxide (ATO) has been proven to be highly effective in adults with newly diagnosed or relapsed acute promyelocytic leukemia (APL). Only very limited data are published on the use of ATO as a single agent for first-line therapy of relapsed APL. The authors present a case of a 8-year-old boy with a bone marrow relapse of APL 7 years after first diagnosis, who achieved durable molecular remission with ATO as single agent: induction therapy for 12 weeks, consolidation for 4 weeks, then 6 cycles of 10 days over a period of 6 months. In total, 140 doses of ATO (0.15 mg/kg/day) were given (21 mg/kg). Consecutive promyelocytic leukemia-retinoic acid receptor α (PML-RARα) RT-PCR analyses were negative with a follow-up of 48 months. Acute or late side effects of arsenic were not observed. At present, the boy is in complete remission 4 years after the diagnosis of the relapse.

High proportion of leukemic stem cells at diagnosis is correlated with unfavorable prognosis in childhood acute myeloid leukemia.

In acute myeloid leukemia (AML), the leukemia-initiating cell is found within the CD34(+)/CD38(-) cell compartment. Over the last years evidence grew that AML is initiated and propagated by leukemic stem cells (LSCs). Conceivably, these most immature leukemia cells are more resistant to therapy and subsequently initiate relapse. The authors studied 17 patients with childhood AML treated according to the AML-BFM 98/04 protocol. At diagnosis, the authors determined the characteristic immunophenotype of the leukemic cells by flow cytometry and investigated the expression of CD34, CD38, and CD45 to define a population of immunophenotypically immature cells (CD34(+)/CD38(-)/CD45(-/low)) enriched for LSCs in many cases of AML. The authors compared the fraction of this population of all myeloid cells at diagnosis with event-free survival. Kaplan-Meier analysis revealed significant higher event free survival of patients with low CD34(+)/CD38(-)/CD45(-/low) cell proportion (<0.68%) compared to patients with high burden of this population (>0.83%; log-rank P < .04). This correlation was not found for the total number of CD34(+) cells. This is the first study to show that a higher proportion of immature CD34(+)/CD38(-)/CD45(-/low) blasts at diagnosis correlates with unfavorable prognosis in childhood AML. The results suggest that a large CD34(+)/CD38(-)/CD45(-/low) population reflects a higher fraction of LSCs, leading to increased chemotherapy resistance and elevated relapse rate. Thus the initial frequency of CD34(+)/CD38(-)/CD45(-/low) cells may serve as a prognostic marker in pediatric AML. Future treatment in childhood AML should specifically target this immature population as well as the mature blast population.

Late complications after hematopoietic stem cell transplantation.

Hematopoietic stem cell transplantation (HSCT) offers the opportunity for cure to patients with leukemia, lymphoma and severe non-malignant diseases. More than 40,000 HSCTs are performed annually worldwide. Therefore, the number of long-term survivors, free of the disease for which they were transplanted is continuously increasing. Despite the improved prognosis of HSCT, long-term outcome may be impaired by transplant-associated morbidity and mortality. Long-term survivors can present a variety of malignant and non-malignant complications, impairing physical and psychological performance, normal integration in family and social life, and quality of life. Conditioning regimens, particularly when including total-body irradiation as well as graft-versus-host disease, play a key role in the development of late effects. However, with increasing time since transplantation new types of late effects may emerge. Awareness on long-term effects after HSCT is crucial to provide adapted pretransplant counseling, and recommendations for post-transplant screening, prevention and early treatment.