Relevance of lymphocyte proliferation to PHA in severe combined immunodeficiency (SCID) and T cell lymphopenia

Severe combined immunodeficiency (SCID) is characterized by a severe deficiency in T cell numbers. We analyzed data collected (n = 307) for PHA-based T cell proliferation from the PIDTC SCID protocol 6901, using either a radioactive or flow cytometry method. In comparing the two groups, a smaller number of the patients tested by flow cytometry had <10% of the lower limit of normal proliferation as compared to the radioactive method (p = 0.02). Further, in patients with CD3+ T cell counts between 51 and 300 cells/μL, there was a higher proliferative response with the PHA flow assay compared to the 3H-T assay (p < 0.0001), suggesting that the method of analysis influences the resolution and interpretation of PHA results. Importantly, we observed many SCID patients with profound T cell lymphopenia having normal T cell proliferation when assessed by flow cytometry. We recommend this test be considered only as supportive in the diagnosis of typical SCID.

Novel Compound Heterozygous ZAP70 R37G A507T Mutations in Infant with Severe Immunodeficiency

Zeta-chain associated protein kinase 70 kDa (ZAP70) combined immunodeficiency (CID) is an autosomal recessive severe immunodeficiency that is characterized by abnormal T-cell receptor signaling. Children with the disorder typically present during the first year of life with diarrhea, failure to thrive, and recurrent bacterial, viral, or opportunistic infections. To date, the only potential cure is hematopoietic stem cell transplant (HSCT). The majority of described mutations causing disease occur in the homozygous state, though heterozygotes are reported without a clear understanding as to how the individual mutations interact to cause disease. This case describes an infant with novel ZAP-70 deficiency mutations involving the SH2 and kinase domains cured with allogeneic HSCT utilizing a reduced-intensity conditioning regimen and graft manipulation. We then were able to further elucidate the molecular signaling alterations imparted by these mutations that lead to altered immune function. In order to examine the effect of these novel compound ZAP70 heterozygous mutations on T cells, Jurkat CD4+ T cells were transfected with either wild type, or with individual ZAP70 R37G and A507T mutant constructs. Downstream TCR signaling events and protein localization results link these novel mutations to the expected immunological outcome as seen in the patient's primary cells. This study further characterizes mutations in the ZAP70 gene as combined immunodeficiency and the clinical phenotype.

Prospective PTCTC trial of myeloablative haplo-BMT with posttransplant cyclophosphamide for pediatric acute leukemias

Promising results have been reported for adult patients with high-risk hematologic malignancies undergoing haploidentical bone marrow transplant (haploBMT) with posttransplant cyclophosphamide (PTCy). To our knowledge, we report results from the first multicenter trial for pediatric and young adult patients with high-risk acute leukemias and myelodysplastic syndrome (MDS) in the Pediatric Transplantation and Cellular Therapy Consortium. Nine centers performed transplants in 32 patients having acute leukemias or MDS, with myeloablative conditioning (MAC), haploBMT with PTCy, mycophenolate mofetil, and tacrolimus. The median patient age was 12 years. Diagnoses included AML (15), ALL (11), mixed-lineage leukemia (1), and MDS (5). Transplant-related mortality (TRM) at 180 days was 0%. The cumulative incidence (CuI) of grade 2 acute graft-versus-host disease (aGVHD) on day 100 was 13%. No patients developed grades 3-4 aGVHD. The CuI of moderate-to-severe chronic GVHD (cGVHD) at 1 year was 4%. Donor engraftment occurred in 27 patients (84%). Primary graft failures included 3 patients who received suboptimal bone marrow grafts; all successfully engrafted after second transplants. The CuI of relapse at 1 year was 32%, with more relapse among patients MRD positive pre-BMT vs MRD negative. Overall survival rates at 1 and 2 years were 77% and 73%, and event-free survival rate at 1 and 2 years were 68% and 64%. There was no TRM or severe aGVHD, low cGVHD, and favorable relapse and survival rates. This successful pilot trial has led to a phase 3 trial comparing MAC haploBMT vs HLA-matched unrelated donor BMT in the Children's Oncology Group. This trial was registered at www.clinicaltrials.gov as #NCT02120157.

Phase II trial of gemcitabine and nab-paclitaxel for recurrent osteosarcoma: A report from the National Pediatric Cancer Foundation

10042

Background: The combination of gemcitabine and docetaxel is often used to treat patients with recurrent osteosarcoma. A retrospective study of 35 such patients has reported an objective response rate of 17% and 4-month progression-free survival (PFS) of 56% with this combination (BMC Cancer 2016;16:280). Nab-paclitaxel is a nanoparticle taxane that has activity against osteosarcoma xenografts and may have less myelosuppression than docetaxel. The combination of gemcitabine and nab-paclitaxel is now frontline therapy for pancreatic cancer. We conducted a prospective multi-institutional phase II trial of this drug combination for patients with recurrent osteosarcoma. Methods: Patients with relapsed/refractory osteosarcoma with measurable disease and age ≥ 12 years and adequate organ function were included. A Simon’s two-stage design was used to identify a 4-month progression-free survival (PFS) of > 35%. Patients received nab-paclitaxel 125 mg/m2 and gemcitabine 1000 mg/m2 weekly x 3 in 4-week cycles. Results: Eighteen patients with a median age 16 years (range 12- 26) received a total of 56 total cycles.(median 2, range 1 - 12). The median number of prior treatment regimens was 3 (range 1-7). Two patients (11%) experienced a partial response, and 6 (33%) received more than 2 cycles. The 4-month PFS was 30% (95% CI 14-62 %). Six patients required dose reductions for neutropenia (n = 4), pleural effusion (1), or neuropathy (1). Two patients were removed from study secondary to neutropenia despite dose reduction and myeloid growth factor support, and one patient came off study due to severe peripheral edema. Conclusions: In this prospective study, the combination of gemcitabine and nab-paclitaxel administered on this schedule showed only limited activity for patients with heavily pretreated recurrent osteosarcoma. Toxicity led to dose modifications in 33% and discontinuation in 17% of patients. When compared to a historical retrospective study, the substitution of nab-paclitaxel for docetaxel did not appear to increase activity or decrease toxicity for this patient population. Clinical trial information: NCT02945800.

Medical Outcomes, Quality of Life, and Family Perceptions for Outpatient vs Inpatient Neutropenia Management After Chemotherapy for Pediatric Acute Myeloid Leukemia

IMPORTANCE

Pediatric acute myeloid leukemia (AML) requires multiple courses of intensive chemotherapy that result in neutropenia, with significant risk for infectious complications. Supportive care guidelines recommend hospitalization until neutrophil recovery. However, there are little data to support inpatient over outpatient management.

OBJECTIVE

To evaluate outpatient vs inpatient neutropenia management for pediatric AML.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used qualitative and quantitative methods to compare medical outcomes, patient health-related quality of life (HRQOL), and patient and family perceptions between outpatient and inpatient neutropenia management. The study included patients from 17 US pediatric hospitals with frontline chemotherapy start dates ranging from January 2011 to July 2019, although the specific date ranges differed for the individual analyses by design and relative timing. Data were analyzed from August 2019 to February 2020.

EXPOSURES

Discharge to outpatient vs inpatient neutropenia management.

MAIN OUTCOMES AND MEASURES

The primary outcomes of interest were course-specific bacteremia incidence, times to next course, and patient HRQOL. Course-specific mortality was a secondary medical outcome.

RESULTS

Primary quantitative analyses included 554 patients (272 [49.1%] girls and 282 [50.9%] boys; mean [SD] age, 8.2 [6.1] years). Bacteremia incidence was not significantly different during outpatient vs inpatient management (67 courses [23.8%] vs 265 courses [29.0%]; adjusted rate ratio, 0.73; 95% CI, 0.56 to 1.06; P = .08). Outpatient management was not associated with delays to the next course compared with inpatient management (mean [SD] 30.7 [12.2] days vs 32.8 [9.7] days; adjusted mean difference, -2.2; 95% CI, -4.1 to -0.2, P = .03). Mortality during intensification II was higher for patients who received outpatient management compared with those who received inpatient management (3 patients [5.4%] vs 1 patient [0.5%]; P = .03), but comparable with inpatient management at other courses (eg, 0 patients vs 5 patients [1.3%] during induction I; P = .59). Among 97 patients evaluated for HRQOL, outcomes did not differ between outpatient and inpatient management (mean [SD] Pediatric Quality of Life Inventory total score, 70.1 [18.9] vs 68.7 [19.4]; adjusted mean difference, -2.8; 95% CI, -11.2 to 5.6). A total of 86 respondents (20 [23.3%] in outpatient management, 66 [76.7%] in inpatient management) completed qualitative interviews. Independent of management strategy received, 74 respondents (86.0%) expressed satisfaction with their experience. Concerns for hospital-associated infections among caregivers (6 of 7 caregiver respondents [85.7%] who were dissatisfied with inpatient management) and family separation (2 of 2 patient respondents [100%] who were dissatisfied with inpatient management) drove dissatisfaction with inpatient management. Stress of caring for a neutropenic child at home (3 of 3 respondents [100%] who were dissatisfied with outpatient management) drove dissatisfaction with outpatient management.

CONCLUSIONS AND RELEVANCE

This cohort study found that outpatient neutropenia management was not associated with higher bacteremia incidence, treatment delays, or worse HRQOL compared with inpatient neutropenia management among pediatric patients with AML. While outpatient management may be safe for many patients, course-specific mortality differences suggest that outpatient management in intensification II should be approached with caution. Patient and family experiences varied, suggesting that outpatient management may be preferred by some but may not be feasible for all families. Further studies to refine and standardize safe outpatient management practices are warranted.

Hematopoietic Cell Transplantation in Patients With Primary Immune Regulatory Disorders (PIRD): A Primary Immune Deficiency Treatment Consortium (PIDTC) Survey

Primary Immune Regulatory Disorders (PIRD) are an expanding group of diseases caused by gene defects in several different immune pathways, such as regulatory T cell function. Patients with PIRD develop clinical manifestations associated with diminished and exaggerated immune responses. Management of these patients is complicated; oftentimes immunosuppressive therapies are insufficient, and patients may require hematopoietic cell transplant (HCT) for treatment. Analysis of HCT data in PIRD patients have previously focused on a single gene defect. This study surveyed transplanted patients with a phenotypic clinical picture consistent with PIRD treated in 33 Primary Immune Deficiency Treatment Consortium centers and European centers. Our data showed that PIRD patients often had immunodeficient and autoimmune features affecting multiple organ systems. Transplantation resulted in resolution of disease manifestations in more than half of the patients with an overall 5-years survival of 67%. This study, the first to encompass disorders across the PIRD spectrum, highlights the need for further research in PIRD management.

Retinoblastoma Control With Primary Intra-arterial Chemotherapy: Outcomes Before and During the Intravitreal Chemotherapy Era

PURPOSE

To compare outcomes of intra-arterial chemotherapy for retinoblastoma as primary therapy before (Era I) and during (Era II) the intravitreal chemotherapy era.

METHODS

In this retrospective interventional case series at a tertiary referral center, 66 eyes of 66 patients with untreated unilateral retinoblastoma were used. intraarterial chemotherapy into the ophthalmic artery under fluoroscopic guidance was performed using melphalan in every case, with additional topotecan as necessary. Intravitreal chemotherapy using melphalan and/or topotecan was employed as needed for active vitreous seeding. Globe salvage was measured based on the International Classification of Retinoblastoma (ICRB) during two eras.

RESULTS

The two eras encompassed 2008 to 2012 (intraarterial chemotherapy alone, Era I) and 2012 to 2015 (intraarterial chemotherapy plus intravitreal chemotherapy, Era II). Over this period, there were 66 patients with unilateral untreated retinoblastoma treated with primary intra-arterial chemotherapy. A comparison of features (Era I vs Era II) revealed no significant difference in mean patient age (24 vs 24 months), ICRB groups, mean largest tumor diameter (19 vs 17 mm), mean largest tumor thickness (10 vs 10 mm), vitreous seed presence (56% vs 59%), subretinal seed presence (67% vs 62%), retinal detachment (70% vs 66%), or vitreous hemorrhage (0% vs 5%). There was no significant difference in mean number of intra-arterial chemotherapy cycles (3 vs 3.1) or intraarterial chemotherapy dosages. Following therapy, there was a significant difference (Era I vs Era II) in the need for enucleation overall (44% vs 15%, P = .012), especially for group E eyes (75% vs 27%, P = .039). Four of the eyes that initiated therapy in Era I later required intravitreal chemotherapy during Era II. The enucleation rate was 0% for groups B and C in both eras and non-significant for group D (23% vs 13%). There were no patients with stroke, seizure, limb ischemia, extraocular tumor extension, secondary leukemia, metastasis, or death.

CONCLUSIONS

The current era of retinoblastoma management using intra-arterial chemotherapy plus additional intravitreal chemotherapy (as needed for vitreous seeding) has improved globe salvage in eyes with advanced retinoblastoma. [J Pediatr Ophthalmol Strabismus. 2016;53(5):275-284.].

Pediatric chronic myeloid leukemia with inv(3)(q21q26.2) and T lymphoblastic transformation: a case report

Background

Chronic myeloid leukemia (CML) comprises ~3 % of pediatric leukemia. Although therapy with tyrosine kinase inhibitors (TKIs) is highly effective for CML, multiple factors have been identified as predictive of treatment failure. Chromosomal abnormalities involving the MECOM locus at 3q26 portend therapy resistant disease in adults, yet have never been described in pediatric patients and have not been associated with T lymphoblastic progression.

Case presentation

We present a case of an 11-year-old boy with CML possessing the unique combination of T lymphoblastic transformation and a subclone harboring inv(3)(q21q26.2) at diagnosis. This is the first reported case of pediatric CML with inv(3)(q21q26.2) and the first case of T lymphoblastic progression associated with this karyotype. The patient was treated with single agent TKI therapy with robust initial response. Marrow histology at one month showed restoration of trilineage hematopoiesis and BCR-ABL RT-PCR at three months showed a 1.4 log reduction in transcript levels.

Conclusions

The karyotypic abnormality of inv(3)(q21q26.2) in CML is not restricted to adult patients. Moreover, while chromosome 3 abnormalities are markers of TKI resistance in adults, our patient showed a robust early response to single agent TKI therapy. This finding suggests pediatric CML with inv(3)(q21q26.2) may have distinct features and more favorable treatment responses than those described in adults.

Unilateral Retinoblastoma Managed With Intravenous Chemotherapy Versus Intra-Arterial Chemotherapy. Outcomes Based on the International Classification of Retinoblastoma

PURPOSE

The objective of this study was to compare outcomes after intravenous chemotherapy (IVC) versus intra-arterial chemotherapy (IAC) for unilateral retinoblastoma.

DESIGN

A retrospective comparative interventional case series.

METHODS

Patients with unilateral retinoblastoma managed with either IVC using vincristine, etoposide, and carboplatin or IAC using melphalan with or without topotecan with a minimum of 1-year follow-up were compared. The primary outcome measure was globe salvage.

RESULTS

Of 91 patients with unilateral retinoblastoma, IVC was employed in 42 (46%) cases and IAC in 49 (54%). By comparison (IVC vs IAC), patients in the IAC group had greater mean tumor diameter (14 vs 18 mm, P < 0.001) and thickness (7 vs 10 mm, P = 0.001), greater percentage with active vitreous seeds (29% vs 55%, P = 0.01), and greater total retinal detachment (10% vs 43%, P < 0.001). There were no cases of group A in either treatment arm. Globe salvage was not significantly different in groups B, C, or E, but there was significantly improved globe salvage with IAC for group D (48% vs 91%, P = 0.004). Control was significantly better with IAC for solid tumor (62% vs 92%, P = 0.002), subretinal seeds (31% vs 86%, P = 0.006), and vitreous seeds (25% vs 74%, P = 0.006). There were no patients with pinealoblastoma, second cancer, metastasis, or death in either group.

CONCLUSIONS

For unilateral retinoblastoma, IAC provided significantly superior globe salvage compared with IVC for group D eyes. In addition, IAC provided significantly superior control for solid tumor, subretinal seeds, and vitreous seeds.