CD4+ T-cell reconstitution predicts survival outcomes after acute graft-versus-host-disease: a dual-center validation.

Acute graft-versus-host-Disease (aGVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). We previously showed that early CD4+ T-cell immune reconstitution (IR; CD4+ IR) predicts survival after HCT. Here, we studied the relation between CD4+ IR and survival in patients developing aGVHD. Pediatric patients undergoing first allogeneic HCT at University Medical Center Utrecht (UMC)/Princess Máxima Center (PMC) or Memorial Sloan Kettering Cancer Center (MSK) were included. Primary outcomes were nonrelapse mortality (NRM) and overall survival (OS), stratified for aGVHD and CD4+ IR, defined as ≥50 CD4+ T cells per µL within 100 days after HCT or before aGVHD onset. Multivariate and time-to-event Cox proportional hazards models were applied, and 591 patients (UMC/PMC, n = 276; MSK, n = 315) were included. NRM in patients with grade 3 to 4 aGVHD with or without CD4+ IR within 100 days after HCT was 30% vs 80% (P = .02) at UMC/PMC and 5% vs 67% (P = .02) at MSK. This was associated with lower OS without CD4+ IR (UMC/PMC, 61% vs 20%; P = .04; MSK, 75% vs 33%; P = .12). Inadequate CD4+ IR before aGVHD onset was associated with significantly higher NRM (74% vs 12%; P < .001) and inferior OS (24% vs 78%; P < .001). In this retrospective analysis, we demonstrate that early CD4+ IR, a simple and robust marker predictive of outcomes after HCT, is associated with survival after moderate to severe aGVHD. This association must be confirmed prospectively but suggests strategies to improve T-cell recovery after HCT may influence survival in patients developing aGVHD.

Risk Factors, Treatment, and Immune Dysregulation in Autoimmune Cytopenia after Allogeneic Hematopoietic Stem Cell Transplantation in Pediatric Patients.

Autoimmune or alloimmune cytopenia (AIC) is a known rare complication of hematopoietic stem cell transplantation (SCT). AIC after SCT is considered difficult to treat and is associated with high morbidity and mortality. In this retrospective study in pediatric patients we evaluated incidence, outcome, potential risk factors, and current treatment strategies. A nested matched case-control study was performed to search for biomarkers associated with AIC. Of 531 consecutive SCTs at our center between 2000 and 2016, 26 were complicated by the development of AIC (cumulative incidence, 5.0%) after a median of 5 months post-SCT. Autoimmune hemolytic anemia was the most common AIC with 12 patients (46%). We identified nonmalignant disease, alemtuzumab serotherapy pre-SCT, and cytomegalovirus (CMV) reactivation as independently associated risk factors. The cytokine profile of patients at the time of AIC diagnosis appeared to skew toward a more pronounced Th 2 response compared with control subjects at the corresponding time point post-SCT. Corticosteroids and intravenous immunoglobulin as first-line treatment or a wait-and-see approach led to resolution of AIC in 35% of cases. Addition of step-up therapies rituximab (n = 15), bortezomib (n = 7), or sirolimus (n = 3) was associated with AIC resolution in 40%, 57%, and 100% of cases, respectively. In summary, we identified CMV reactivation post-SCT as a new clinical risk factor for the development of AIC in children. The cytokine profile during AIC appears to favor a Th 2 response. Rituximab, bortezomib, and sirolimus are promising step-up treatment modalities.

Efficacy and safety of recombinant E. coli asparaginase in children with previously untreated acute lymphoblastic leukemia: A randomized multicenter study of the Dutch Childhood Oncology Group.

BACKGROUND: The efficacy and safety of recombinant Escherichia coli-asparaginase (rASNase) was compared to native E.coli asparaginase (Asparaginase medac). METHODS: One hundred and ninety-nine children with newly diagnosed acute lymphoblastic leukemia were randomized to receive one of both agents at a dose of 5,000 U/m² during induction (eight doses) and 10,000 U/m² during the postinduction phase (only high-risk patients; standard- and medium-risk patients received pegaspargase). RESULTS: Median trough serum asparaginase activity levels were comparable between both groups; they ranged from 143 to 182 U/l during induction and were above the target value of 100 U/l. Complete asparagine depletion in serum was achieved in 97.9% of patients, with no significant differences between both groups. On day 33 (end of induction), only two (2%) evaluable patients in each group had measurable asparagine serum levels, and complete asparagine depletion in the cerebrospinal fluid was achieved in 98.8% and 93.6% of the patients with rASNase and Asparaginase medac, respectively. During induction, 2.1% and 5% of patients developed an allergic reaction to rASNase or Asparaginase medac, respectively. Approximately 41% of the patients in both groups had a clinical allergy or enzyme inactivation to the first dose of any asparaginase preparation in postinduction. A comparable proportion of patients in both groups developed anti-asparaginase antibodies (57%) during repeated administration of asparaginase. Minimal residual disease levels at the end of induction, 5-year event-free survival, and 5-year cumulative incidence of relapse did not differ between both groups. CONCLUSION: The efficacy, safety, and immunogenicity of both asparaginase preparations are comparable. This trial was registered at www.clinicaltrials.gov as #NCT00784017; EudraCT number 2006-003180-31.

Population pharmacokinetics of intravenous Erwinia asparaginase in pediatric acute lymphoblastic leukemia patients.

Erwinia asparaginase is an important component in the treatment of pediatric acute lymphoblastic leukemia. A large variability in serum concentrations has been observed after intravenous Erwinia asparaginase. Currently, Dutch Childhood Oncology Group protocols dose alterations are based on trough concentrations to ensure adequate asparaginase activity (≥100 IU/L). The aim of this study was to describe the population pharmacokinetics of intravenous Erwinia asparaginase to quantify and gather insight into inter-individual and inter-occasion variability. The starting dose was evaluated on the basis of the derived population pharmacokinetic parameters. In a multicenter prospective observational study, a total of 714 blood samples were collected from 51 children (age 1-17 years) with acute lymphoblastic leukemia. The starting dose was 20,000 IU/m2 three times a week and adjusted according to trough levels from week three onwards. A population pharmacokinetic model was developed using NONMEM® A 2-compartment linear model with allometric scaling best described the data. Inter-individual and inter-occasion variability of clearance were 33% and 13%, respectively. Clearance in the first month of treatment was 14% higher (P<0.01). Monte Carlo simulations with our pharmacokinetic model demonstrated that patients with a low weight might require higher doses to achieve similar concentrations compared to patients with high weight. The current starting dose of 20,000 IU/m2 might result in inadequate concentrations, especially for smaller, lower weight patients, hence dose adjustments based on individual clearance are recommended. The protocols were approved by the institutional review boards. (Registered at NTR 3379 Dutch Trial Register; www.trialregister.nl).

Recurrent translocation t(10;17)(p15;q21) in minimally differentiated acute myeloid leukemia results in ZMYND11/MBTD1 fusion.

Pediatric acute myeloid leukemia (AML) is a heterogeneous disease, characterized by different collaborating karyotypic and molecular abnormalities, which are used in risk group stratification. In ∼20% of the pediatric AML cases a specific genetic aberration is still unknown. Minimally differentiated myeloid leukemia or FAB-type M0 is a rare morphological subtype of AML. The translocation t(10;17)(p15;q21) is described to be recurrent in minimally differentiated AML, but the involved genes and location of the breakpoints have so far not been identified. In this study, we show that this translocation results in an in-frame translocation fusing exon 12 of the tumor suppressor gene ZMYND11 to exon 3 of the chromatin protein MBTD1, encoding a protein of 1,054 amino acids, while the reciprocal fusion product is predicted to lack a productive start codon. Gene expression profiling of the leukemic cells showed high HOXA expression. ZMYND11, also known as BS69, is a tumor suppressor that specifically recognizes H3K36me3, which is linked to aberrant HOXA expression in leukemogenesis. Aberrant expression of the genes involved in this fusion may thus contribute to the HOXA-phenotype observed with gene expression profiling.

Phenotypic variability in patients with ADA2 deficiency due to identical homozygous R169Q mutations.

OBJECTIVE: To determine the genotype-phenotype association in patients with adenosine deaminase-2 (ADA2) deficiency due to identical homozygous R169Q mutations inCECR1 METHODS: We present a case series of nine ADA2-deficient patients with an identical homozygous R169Q mutation. Clinical and diagnostic data were collected and available MRI studies were reviewed. We performed genealogy and haplotype analyses and measured serum ADA2 activity. ADA2 activity values were correlated to clinical symptoms. RESULTS: Age of presentation differed widely between the nine presented patients (range: 0 months to 8 years). The main clinical manifestations were (hepato)splenomegaly (8/9), skin involvement (8/9) and neurological involvement (8/9, of whom 6 encountered stroke). Considerable variation was seen in type, frequency and intensity of other symptoms, which included aplastic anaemia, acute myeloid leukaemia and cutaneous ulcers. Common laboratory abnormalities included cytopenias and hypogammaglobulinaemia. ADA2 enzyme activity in patients was significantly decreased compared with healthy controls. ADA2 activity levels tended to be lower in patients with stroke compared with patients without stroke. Genealogical studies did not identify a common ancestor; however, based on allele frequency, a North-West European founder effect can be noted. Three patients underwent haematopoietic cell transplantation, after which ADA2 activity was restored and clinical symptoms resolved. CONCLUSION: This case series revealed large phenotypic variability in patients with ADA2 deficiency though they were homozygous for the same R169Q mutation inCECR1 Disease modifiers, including epigenetic and environmental factors, thus seem important in determining the phenotype. Furthermore, haematopoietic cell transplantation appears promising for those patients with a severe clinical phenotype.

A prospective study on drug monitoring of PEGasparaginase and Erwinia asparaginase and asparaginase antibodies in pediatric acute lymphoblastic leukemia.

This study prospectively analyzed the efficacy of very prolonged courses of pegylated Escherichia coli asparaginase (PEGasparaginase) and Erwinia asparaginase in pediatric acute lymphoblastic leukemia (ALL) patients. Patients received 15 PEGasparaginase infusions (2500 IU/m(2) every 2 weeks) in intensification after receiving native E coli asparaginase in induction. In case of allergy to or silent inactivation of PEGasparaginase, Erwinia asparaginase (20 000 IU/m(2) 2-3 times weekly) was given. Eighty-nine patients were enrolled in the PEGasparaginase study. Twenty (22%) of the PEGasparaginase-treated patients developed an allergy; 7 (8%) showed silent inactivation. The PEGasparaginase level was 0 in all allergic patients (grade 1-4). Patients without hypersensitivity to PEGasparaginase had serum mean trough levels of 899 U/L. Fifty-nine patients were included in the Erwinia asparaginase study; 2 (3%) developed an allergy and none silent inactivation. Ninety-six percent had at least 1 trough level ≥100 U/L. The serum asparagine level was not always completely depleted with Erwinia asparaginase in contrast to PEGasparaginase. The presence of asparaginase antibodies was related to allergies and silent inactivation, but with low specificity (64%). Use of native E coli asparaginase in induction leads to high hypersensitivity rates to PEGasparaginase in intensification. Therefore, PEGasparaginase should be used upfront in induction, and we suggest that the dose could be lowered. Switching to Erwinia asparaginase leads to effective asparaginase levels in most patients. Therapeutic drug monitoring has been added to our ALL-11 protocol to individualize asparaginase therapy.

The effect of cidofovir on adenovirus plasma DNA levels in stem cell transplantation recipients without T cell reconstitution.

Cidofovir is frequently used to treat life-threatening human adenovirus (HAdV) infections in immunocompromised children after hematopoietic stem cell transplantation (HSCT). However, the antiviral effect irrespective of T cell reconstitution remains unresolved. Plasma HAdV DNA levels were monitored by real-time quantitative PCR during 42 cidofovir treatment episodes for HAdV viremia in 36 pediatric allogeneic HSCT recipients. HAdV load dynamics were related to T and natural killer (NK) cell reconstitution measured by flow cytometry. To evaluate the in vivo antiadenoviral effect of cidofovir, we focused on 20 cidofovir treatment episodes lacking concurrent T cell reconstitution. During 2 to 10 weeks of follow-up in the absence of T cells, HAdV load reduction (n = 7) or stabilization (n = 8) was observed in 15 of 20 treatments. Although HAdV load reduction was always accompanied by NK cell expansion, HAdV load stabilization was measured in 2 children lacking both T and NK cell reconstitution. In cases with T cell reconstitution, rapid HAdV load reduction (n = 14) or stabilization (n = 6) was observed in 20 of 22 treatments. In the absence of T cells, cidofovir treatment was associated with HAdV viremia control in the majority of cases. Although the contribution of NK cells cannot be excluded, cidofovir has the potential to mediate HAdV load stabilization in the time pending T cell reconstitution.

Ovarian insufficiency and pubertal development after hematopoietic stem cell transplantation in childhood.

BACKGROUND: Ovarian insufficiency (OI) and infertility are common and devastating late effects of cancer treatment and hematopoietic stem cell transplantation (HSCT). In children, gonadal insufficiency may subsequently lead to abnormal pubertal development. The aim of this study was to assess the cumulative incidence of OI and the need for hormonal induction of pubertal development after HSCT in childhood. We additionally assessed HSCT-related risk factors for OI. PROCEDURES: A single center cohort study was undertaken of female patients transplanted during childhood, surviving at least 2 years post-HSCT and who were at least 10 years old at initiation of the study. Of 141 eligible patients, 109 were included and hormone levels and clinical data of these patients during follow-up were collected. Risk factors for OI were analyzed by multivariate Cox regression analysis. RESULTS: Cumulative incidence of OI was 56% at a median follow-up of 7.2 years. Eight patients, initially diagnosed with OI, showed recovery of ovarian function over time. Hormonal induction of puberty was necessary in 44% of females who were pre-pubertal or pubertal at HSCT. In multivariate analysis, more advanced pubertal stage at HSCT was associated with OI. We found a trend for an association of busulfan with OI in patients conditioned with chemotherapy only. CONCLUSIONS: The incidence of OI after HSCT was high and associated with more advanced pubertal stage at HSCT. Almost half of the females who were pre-pubertal or pubertal at HSCT required hormonal induction of pubertal development.

Excellent leukemia control after second hematopoietic cell transplants with unrelated cord blood grafts for post-transplant relapse in pediatric patients.

Background: Patients with leukemia relapse after allogeneic hematopoietic cell transplant (HCT) have poor survival due to toxicity and disease progression. A second HCT often offers the only curative treatment. Methods: We retrospectively reviewed our bi-institutional experience (MSKCC-USA; Utrecht-NL) with unrelated cord blood transplantation (CBT) for treatment of post-transplant relapse. Overall survival (OS) and event-free survival (EFS) were evaluated using the Kaplan-Meier method, treatment-related mortality (TRM) and relapse were evaluated using the competing risk method by Fine-Gray. Results: Twenty-six patients age < 21 years received a second (n=24) or third (n=2) HCT with CB grafts during the period 2009-2021. Median age at first HCT (HCT1) was 11.5 (range: 0.9-17.7) years and all patients received myeloablative cytoreduction. Median time from HCT1 to relapse was 12.8 (range 5.5-189) months. At CBT, median patient age was 13.5 (range 1.4-19.1) years. Diagnoses were AML: 13; ALL: 4, MDS: 5, JMML: 2; CML: 1; mixed phenotype acute leukemia: 1. Sixteen patients (62%) were in advanced stage, either CR>2 or with active disease. Median time from HCT1 to CBT was 22.2 (range 7-63.2) months. All patients engrafted after CBT. Thirteen patients developed acute GvHD; 7 had grade III or IV. With a median survivor follow-up of 46.6 (range 17.4-155) months, 3-year OS was 69.2% (95% CI 53.6-89.5%) and 3-year EFS was 64.9% (95% CI 48.8-86.4%). Eight patients died, 3 of AML relapse and 5 due to toxicity (respiratory failure [n=4], GvHD [n=1]) at a median time of 7.7 (range 5.9-14.4) months after CBT. Cumulative incidence of TRM at 3 years was 19.2% (95% CI 4.1-34.4%). Notably, all TRM events occurred in patients transplanted up to 2015; no toxicity-related deaths were seen in the 16 patients who received CBT after 2015. Cumulative incidence of relapse was 15.9% (95% CI 1.6-30.2%) at 3 years, remarkably low for these very high-risk patients. Conclusions: Survival was very encouraging following CB transplants in pediatric patients with recurrent leukemia after first HCT, and TRM has been low over the last decade. CBT needs to be strongly considered as a relatively safe salvage therapy option for post-transplant relapse.

A joint international consensus statement for measuring quality of survival for patients with childhood cancer.

The aim of treating childhood cancer remains to cure all. As survival rates improve, long-term health outcomes increasingly define quality of care. The International Childhood Cancer Outcome Project developed a set of core outcomes for most types of childhood cancers involving relevant international stakeholders (survivors; pediatric oncologists; other medical, nursing or paramedical care providers; and psychosocial or neurocognitive care providers) to allow outcome-based evaluation of childhood cancer care. A survey among healthcare providers (n = 87) and online focus groups of survivors (n = 22) resulted in unique candidate outcome lists for 17 types of childhood cancer (five hematological malignancies, four central nervous system tumors and eight solid tumors). In a two-round Delphi survey, 435 healthcare providers from 68 institutions internationally (response rates for round 1, 70-97%; round 2, 65-92%) contributed to the selection of four to eight physical core outcomes (for example, heart failure, subfertility and subsequent neoplasms) and three aspects of quality of life (physical, psychosocial and neurocognitive) per pediatric cancer subtype. Measurement instruments for the core outcomes consist of medical record abstraction, questionnaires and linkage with existing registries. This International Childhood Cancer Core Outcome Set represents outcomes of value to patients, survivors and healthcare providers and can be used to measure institutional progress and benchmark against peers.

Clofarabine-fludarabine-busulfan in HCT for pediatric leukemia: an effective, low toxicity, TBI-free conditioning regimen.

We prospectively studied clofarabine-fludarabine-busulfan (CloFluBu)-conditioning in allogeneic hematopoietic cell therapy (HCT) for lymphoid and myeloid malignancies and hypothesized that CloFluBu provides a less toxic alternative to conventional conditioning regimens, with adequate antileukemic activity. All patients receiving their first HCT, from 2011-2019, were included and received CloFluBu. The primary endpoint was event-free survival (EFS). Secondary endpoints were overall survival (OS), graft-versus-host disease (GvHD)-relapse-free survival (GRFS), treatment-related mortality (TRM), cumulative incidence of relapse (CIR), acute and chronic GvHD (aGvHD and cGvHD), and veno-occlusive disease (VOD). Cox proportional hazard and Fine and Gray competing-risk models were used for data analysis. One hundred fifty-five children were included: 60 acute lymphoid leukemia (ALL), 69 acute myeloid leukemia (AML), and 26 other malignancies (mostly MDS-EB). The median age was 9.7 (0.5 to 18.6) years. Estimated 2-year EFS was 72.0% ± 6.0 in ALL patients, and 62.4% ± 6.0 in AML patients. TRM in the whole cohort was 11.0% ± 2.6, incidence of aGvHD 3 to 4 at 6 months was 12.3% ± 2.7, extensive cGvHD at 2 years was 6.4% ± 2.1. Minimal residual disease-positivity prior to HCT was associated with higher CIR, both in ALL and AML. CloFluBu showed limited toxicity and encouraging EFS. CloFluBu is a potentially less toxic alternative to conventional conditioning regimens. Randomized prospective studies are needed.

A panel of artificial APCs expressing prevalent HLA alleles permits generation of cytotoxic T cells specific for both dominant and subdominant viral epitopes for adoptive therapy.

Adoptive transfer of virus-specific T cells can treat infections complicating allogeneic hematopoietic cell transplants. However, autologous APCs are often limited in supply. In this study, we describe a panel of artificial APCs (AAPCs) consisting of murine 3T3 cells transduced to express human B7.1, ICAM-1, and LFA-3 that each stably express one of a series of six common HLA class I alleles. In comparative analyses, T cells sensitized with AAPCs expressing a shared HLA allele or autologous APCs loaded with a pool of 15-mer spanning the sequence of CMVpp65 produced similar yields of HLA-restricted CMVpp65-specific T cells; significantly higher yields could be achieved by sensitization with AAPCs transduced to express the CMVpp65 protein. T cells generated were CD8(+), IFN-gamma(+), and exhibited HLA-restricted CMVpp65-specific cytotoxicity. T cells sensitized with either peptide-loaded or transduced AAPCs recognized epitopes presented by each HLA allele known to be immunogenic in humans. Sensitization with AAPCs also permitted expansion of IFN-gamma(+) cytotoxic effector cells against subdominant epitopes that were either absent or in low frequencies in T cells sensitized with autologous APCs. This replenishable panel of AAPCs can be used for immediate sensitization and expansion of virus-specific T cells of desired HLA restriction for adoptive immunotherapy. It may be of particular value for recipients of transplants from HLA-disparate donors.

Improving Handoff by Deliberate Cognitive Processing: Results from a Randomized Controlled Experimental Study.

BACKGROUND: Although a number of successful handoff interventions have been reported, the handoff process remains vulnerable because it relies on memory. The aim of this study was to investigate the effect of deliberate cognitive processing (i.e., analytical, conscious, and effortful thinking) on recall of information from a simulated handoff. METHODS: This two-phased experiment was executed in the Netherlands in 2015. A total of 78 pediatric residents were randomly divided into an intervention group (n = 37) and a control group (n = 41). In phase 1, participants received written handoffs from 8 patients. The intervention group was asked to develop a contingency plan for each patient, deliberately processing the information. The control group received no specific instructions. In phase 2, all participants were asked to write down as much as they recalled from the handoffs. The outcome was the amount and accuracy of recalled information, calculated by scoring for idea units (single information elements) and inferences (conclusions computed by participants based on two or more idea units). RESULTS: Participants in the intervention group recalled significantly more inferences (7.24 vs. 3.22) but fewer correct idea units (21.1% vs. 25.3%) than those in the control group. There was no difference with regard to incorrectly recalled information. CONCLUSION: Our study revealed that deliberate cognitive processing leads to creation of more correct inferences, but fewer idea units. This suggests that deliberate cognitive processing results in interpretation of the information into higher level concepts, rather than remembering specific pieces of information separately. This implies better understanding of patients' problems.

Atypical varicella zoster infection associated with hemophagocytic lymphohistiocytosis.

Two adolescents, on immunosuppressive therapy for graft-versus-host disease, developed hemophagocytic lymphohistiocytosis (HLH) after varicella zoster virus (VZV) reactivation. In the absence of dermatome restricted characteristic skin lesions, VZV reactivation was not immediately recognized and treatment with acyclovir was delayed. The first patient developed optical neuritis and died 2 months after the VZV episode due to massive intracranial hemorrhage. The second patient presented with severe abdominal pain and pancreatitis, followed by atypical skin eruptions, which prompted a faster diagnosis. Both patients recovered from their HLH, the first patient being successfully treated with immunosuppressive agents and the second with VZV treatment only. These two cases demonstrate the difficulties in recognizing VZV reactivation, and in order to start adequate and timely treatment, the need to consider VZV as a possible cause of HLH in severely immunocompromised patients.

Adoptive transfer of antigen-specific T-cells of donor type for immunotherapy of viral infections following allogeneic hematopoietic cell transplants.

Allogeneic marrow and cytokine-mobilized peripheral blood stem cells adequately depleted of T cells prevent acute and chronic forms of graft versus host disease in HLA-matched and non-identical hosts without any posttransplant immunosuppressive prophylaxis. Current cytoreductive regimens secure consistent durable engraftment, and full donor chimerism. The risk of relapse following such transplants in patients with AML and ALL has been low, and not different from that recorded following unmodified transplants. However, in HLA-disparate hosts the risk of infections caused by EBV, CMV, and certain fungi are increased. To address this limitation, others and we are exploring adoptive immunotherapies with in vitro generated, pathogen-specific T cells. Early clinical trials already indicate the potential of such T cells to treat and prevent life threatening diseases caused by these pathogens, particularly in recipients of T cell depleted grafts who do not require ongoing treatment with immunosuppressive agents, and therefore provide a permissive environment for the expansion and persistence of the T cells following adoptive transfer. New more predictable strategies are under development, which should allow such therapies to be broadly applicable.