Peripheral Blood Smear Detection of Asymptomatic Central Line Infection in a Patient With Sickle Cell Disease.

Sickle cell disease is a lifelong disorder which may be managed by chronic red cell transfusion including exchange transfusion. Chronic indwelling vascular catheters including ports offer convenient and reliable access for red cell exchange but confer risk of complications including infection and thrombosis. Detection of these complications is essential for preserving vascular access and relies on both clinical and laboratory observation. Here we describe a case of asymptomatic port infection detected by manual screening of a peripheral blood smear.

Mycosis Fungoides Preceding Pityriasis Lichenoides et Varioliformis Acuta by Twelve Years in a Pediatric Patient.

ABSTRACT: A 15-year-old boy presented to the pediatric dermatology department with long-standing patch stage CD8+ mycosis fungoides and subsequent development of recurrent pityriasis lichenoides et varioliformis acuta eruptions. There have been rare reports of patients with chronic, recalcitrant pityriasis lichenoides developing mycosis fungoides, but we believe this to be the second case of mycosis fungoides preceding a diagnosis of pityriasis lichenoides, and the first case reported in the pediatric population.

Localized eruptive porokeratosis in pediatric patients following treatment of acute leukemia.

Porokeratosis is a rare diagnosis in the pediatric population, and eruptive disease has been documented prior in patients with history of stem cell transplantation. Comparing various porokeratosis eruptions between patients can be difficult due to limitations in current classification and nomenclature. Here, we discuss a single-institution case series of three children who developed porokeratosis following hematopoietic stem cell transplantation for acute leukemia, and we propose that this presentation be termed localized eruptive porokeratosis (LEP). We present the distinguishing features of this variant by discussing the shortcomings in current nomenclature and also examine the association between porokeratosis and hematopoietic stem cell transplantation in the pediatric population.

Phase I study of the safety and pharmacokinetics of plerixafor in children undergoing a second allogeneic hematopoietic stem cell transplantation for relapsed or refractory leukemia.

The safety, pharmacokinetics, and biological effect of plerixafor in children as part of a conditioning regimen for chemo-sensitization in allogeneic hematopoietic stem cell transplantation (HSCT) have not been studied. This is a phase I study of plerixafor designed to evaluate its tolerability at dose of .24 mg/kg given intravenously on day -4 (level 1); day -4 and day -3 (level 2); or day -4, day -3, and day -2 (level 3) in combination with fludarabine, thiotepa, melphalan, and rabbit antithymocytic globulin for a second allogeneic HSCT in children with refractory or relapsed leukemia. Immunophenotype analysis was performed on blood and bone marrow before and after plerixafor administration. Twelve patients were enrolled. Plerixafor at all 3 levels was well tolerated without dose-limiting toxicity. Transient gastrointestinal side effects of National Cancer Institute-grade 1 or 2 in severity were the most common adverse events. The area under the concentration-time curve increased proportionally to the dose level. Plerixafor clearance was higher in males and increased linearly with body weight and glomerular filtration rate. The clearance decreased and the elimination half-life increased significantly from dose level 1 to 3 (P < .001). Biologically, the proportion of CXCR4(+) blasts and lymphocytes both in the bone marrow and peripheral blood increased after plerixafor administration.

Impact of tyrosine kinase inhibitors on minimal residual disease and outcome in childhood Philadelphia chromosome-positive acute lymphoblastic leukemia.

BACKGROUND: Breakpoint cluster region-Abelson murine leukemia viral oncogene homolog 1 (BCR-ABL1) tyrosine kinase inhibitors (TKIs) improve the outcome of patients with childhood Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) when they are incorporated into postremission induction chemotherapy. To date, no data are available on the impact of TKIs on minimal residual disease (MRD) at the end of induction therapy among patients who have a poor early response to 2 weeks of induction therapy that does not include TKIs. METHODS: The authors analyzed the early response to TKIs during remission induction in children with Ph-positive ALL who were treated at St. Jude Children's Research Hospital. MRD was measured on days 15 and 42 of induction. TKIs were incorporated into induction therapy on day 22 in the post-TKI era. RESULTS: TKIs produced a marked drop in MRD levels: at the end of remission induction, 9 of 11 patients who received imatinib or dasatinib and conventional induction chemotherapy achieved MRD-negative status compared with only 2 of 16 patients who received chemotherapy alone (P < .001). The 5-year event-free survival rate (± standard deviation) was 68.6% ± 19.2% for the 11 patients who received TKIs versus 31.6% ± 9.9% for the 19 patients who did not (P = .022); notably, 2 of the former group underwent hematopoietic stem cell transplantation versus 15 of the latter group (P = .002). MRD levels and outcomes did not differ significantly among 498 patients with standard-risk/high-risk, Ph-negative ALL who were treated in the pre-TKI or post-TKI eras. CONCLUSIONS: TKIs administered in the early phases of therapy can dramatically reduce MRD and improve the outcome of childhood Ph-positive ALL.

Carbon nanotube stimulation of human mononuclear cells to model granulomatous inflammation.

OBJECTIVES: Sarcoidosis is a multisystem inflammatory granulomatous disease of unknown etiology. The disease most often affects the lung and leads to death in 5% of patients. Patients who die often succumb due to progressive fibrotic lung disease. Translational research in sarcoidosis is significantly limited by a paucity of available experimental models. Carbon nanotubes are released into the environment during fuel combustion, manufacturing, and natural fires. Exposed individuals are at risk for cancer, lung inflammation and other chronic pulmonary disorders, including diseases resembling sarcoidosis and pulmonary fibrosis. In this study, we developed and characterized an in vitro experimental model relevant to sarcoidosis using human peripheral blood mononuclear cells (PBMCs) exposed to multiwalled carbon nanotubes (MWCNTs). METHODS: MWCNT-exposed PBMCs were cultured and analyzed by Giemsa staining, immunohistochemistry (IHC) and RNA-seq analysis on days 1 and 7. Normalization and differential expression were calculated using DESeq2, Limma and edgeR methods from Bioconductor (adjP, log2Fold change and rawP). RESULTS: MWCNT stimulation of PBMCs from healthy subjects leads to the formation of granuloma-like cell clusters and stereotypical inflammatory cytokine secretion. PBMC transcriptomic analysis demonstrated activation of defense- and inflammation-related pathways, including the Jak-Stat pathway and TNF signaling pathway. CONCLUSIONS: This model is unique, as cell clustering is seen in the absence of specific antigenic stimulation (e.g., mycobacterial) or the addition of exogenous cytokines. Modeling with PBMCs provides a platform for precision medicine and evaluation of future therapies for granulomatous and fibrotic lung diseases.

The immunophenotype of T-lymphoblastic lymphoma in children and adolescents: a Children's Oncology Group report.

T-lymphoblastic leukaemia (T-ALL) and T-lymphoblastic lymphoma (T-LBL) are neoplasms derived from immature lymphoid cells of T-cell lineage. These neoplasms are biologically similar, but significant differences may exist between the two given their clinical differences. Although ample data regarding the immunophenotypic characterization T-ALL are available, there is a paucity of such data in children and adolescents with T-LBL. We used flow cytometry and/or immunohistochemistry to characterize the immunophenotypic profile of 180 children and adolescents with newly diagnosed T-LBL enrolled in the Children's Oncology Group 5971 study. Multiple T-cell, B-cell, myeloid, and other markers were evaluated. We identified diagnostically useful immunophenotypic features of T-LBL as well as distinct immunophenotypic subgroups, although none of these was statistically related to event-free or overall survival in this retrospective analysis. Further studies of biologically and immunophenotypically distinct subgroups of T-LBL, such as the early T-cell precursor phenotype, are warranted.

Congenital and childhood myeloproliferative disorders with eosinophilia responsive to imatinib.

Eosinophilia is seen in several myeloproliferative disorders (MPD). A subset of MPD involves the platelet-derived growth factor receptor beta (PDGFRB) gene. Imatinib mesylate has been efficacious in treating some of these MPDs. Here we describe two patients with MPD with eosinophilia and PDGFRB rearrangements, one of which was congenital. Both patients were treated with single agent imatinib and continue to be in clinical, hematologic, and cytogenetic remission despite weaning doses. No definite guidelines currently exist regarding the exact dosing and duration of imatinib therapy for these patients.

Cytochemical Characterization of Cerebrospinal Fluid Macrophage Inclusions in Pediatric Patients Receiving Intrathecal Nusinersen (SPINRAZA®) for Spinal Muscular Atrophy.

INTRODUCTION: Spinal muscular atrophy (SMA) is a debilitating neuromuscular disorder caused by biallelic deletion of the SMN1 gene. Nusinersen, an antisense oligonucleotide delivered intrathecally, binds to the pre-mRNA of SMN1's pseudogene, SMN2, to prevent exon skipping and produce functional SMN protein to compensate for the deficiency caused by SMN1 deletion. CASE PRESENTATION: We reviewed 15 cerebrospinal fluid (CSF) cytology specimens from 8 patients receiving nusinersen for SMA. Macrophages with peculiar inclusions ("nusinophages") were seen in 8 specimens from 4 of the patients: 1 infant and 3 children with SMA type 1. This finding has only previously been reported in adults with SMA types 2 and 3 and in 2 infants with SMA type 1. DISCUSSION/CONCLUSION: Specimens containing nusinophages had a significantly higher proportion of macrophages and lower proportion of lymphocytes than those in which nusinophages were not detected. The macrophage inclusions do not represent iron or microorganisms and instead are composed, at least in part, of glycosaminoglycans. Because CSF is a common specimen type, cytotechnologists and cytopathologists need to be aware of these inclusions, so they do not interpret them erroneously as evidence of infection or hemorrhage, especially in light of the fact that oligonucleotide therapy has been approved for a variety of conditions and is currently under investigation for intrathecal delivery in several other neurodegenerative disorders.

Endangered predators and endangered prey: Seasonal diet of Southern Resident killer whales.

Understanding diet is critical for conservation of endangered predators. Southern Resident killer whales (SRKW) (Orcinus orca) are an endangered population occurring primarily along the outer coast and inland waters of Washington and British Columbia. Insufficient prey has been identified as a factor limiting their recovery, so a clear understanding of their seasonal diet is a high conservation priority. Previous studies have shown that their summer diet in inland waters consists primarily of Chinook salmon (Oncorhynchus tshawytscha), despite that species' rarity compared to some other salmonids. During other times of the year, when occurrence patterns include other portions of their range, their diet remains largely unknown. To address this data gap, we collected feces and prey remains from October to May 2004-2017 in both the Salish Sea and outer coast waters. Using visual and genetic species identification for prey remains and genetic approaches for fecal samples, we characterized the diet of the SRKWs in fall, winter, and spring. Chinook salmon were identified as an important prey item year-round, averaging ~50% of their diet in the fall, increasing to 70-80% in the mid-winter/early spring, and increasing to nearly 100% in the spring. Other salmon species and non-salmonid fishes, also made substantial dietary contributions. The relatively high species diversity in winter suggested a possible lack of Chinook salmon, probably due to seasonally lower densities, based on SRKW's proclivity to selectively consume this species in other seasons. A wide diversity of Chinook salmon stocks were consumed, many of which are also at risk. Although outer coast Chinook samples included 14 stocks, four rivers systems accounted for over 90% of samples, predominantly the Columbia River. Increasing the abundance of Chinook salmon stocks that inhabit the whales' winter range may be an effective conservation strategy for this population.

Enhanced T-cell immunity to osteosarcoma through antibody blockade of PD-1/PD-L1 interactions.

Osteosarcoma is the most common bone cancer in children and adolescents. Although 70% of patients with localized disease are cured with chemotherapy and surgical resection, patients with metastatic osteosarcoma are typically refractory to treatment. Numerous lines of evidence suggest that cytotoxic T lymphocytes (CTLs) limit the development of metastatic osteosarcoma. We have investigated the role of PD-1, an inhibitory TNFR family protein expressed on CTLs, in limiting the efficacy of immune-mediated control of metastatic osteosarcoma. We show that human metastatic, but not primary, osteosarcoma tumors express a ligand for PD-1 (PD-L1) and that tumor-infiltrating CTLs express PD-1, suggesting this pathway may limit CTLs control of metastatic osteosarcoma in patients. PD-L1 is also expressed on the K7M2 osteosarcoma tumor cell line that establishes metastases in mice, and PD-1 is expressed on tumor-infiltrating CTLs during disease progression. Blockade of PD-1/PD-L1 interactions dramatically improves the function of osteosarcoma-reactive CTLs in vitro and in vivo, and results in decreased tumor burden and increased survival in the K7M2 mouse model of metastatic osteosarcoma. Our results suggest that blockade of PD-1/PD-L1 interactions in patients with metastatic osteosarcoma should be pursued as a therapeutic strategy.

Comparative analysis of different approaches to measure treatment response in acute myeloid leukemia.

PURPOSE: In acute myeloid leukemia (AML), initial treatment response by morphologic analysis of bone marrow predicts long-term outcome. Response can now be assessed by minimal residual disease (MRD) monitoring with flow cytometry or polymerase chain reaction (PCR). We determined the relation among the results of these approaches and their prognostic value. PATIENTS AND METHODS: In the multicenter AML02 study, follow-up bone marrow samples from 203 children and adolescents with newly diagnosed AML were examined by flow cytometry (n = 1,514), morphology (n = 1,382), and PCR amplification of fusion transcripts (n = 508). Results were correlated with treatment outcome. RESULTS: Among 1,215 samples with less than 5% leukemic myeloblasts by morphology, 100 (8.2%) were MRD positive (≥ 0.1%) by flow cytometry, whereas 96 (57.5%) of the 167 samples with ≥ 5% blasts were MRD negative. Virtually all (308 of 311; 99.0%) MRD-negative samples by PCR were also MRD negative by flow cytometry. However, only 19 (9.6%) of the 197 PCR-positive samples were flow cytometry positive, with analyses of AML1-ETO and CBFß-MYH11 accounting for most discrepancies, whereas eight of 13 MLL-positive samples had detectable MRD by flow cytometry. MRD by flow cytometry after induction 1 or 2 predicted lower event-free survival and higher relapse rate (P < .001) and was an independent prognostic factor in a multivariable analysis; prediction was not improved by morphologic information or molecular findings. CONCLUSION: In childhood AML, morphologic assessment of treatment response has limited value if MRD is measured by flow cytometry. MLL fusion transcripts can provide prognostic information in some patients, whereas monitoring of AML1-ETO and CBFß-MYH11 transcripts is largely uninformative.

Age and gender specific pediatric reference intervals for aldolase, amylase, ceruloplasmin, creatine kinase, pancreatic amylase, prealbumin, and uric acid.

BACKGROUND: Reference intervals can vary based on age and gender. Proper partitioning is necessary to classify health status in different age groups. METHODS: Seven analytes; aldolase, amylase, ceruloplasmin, creatine kinase, pancreatic amylase, prealbumin and uric acid; were assayed on Roche Modular P analyzers using serum samples from 1765 children (867 females and 898 males; age range, 6 months to 17 y). Subjects 6 months up to 7 y were undergoing minor surgical procedures. Children 7 to 17 y were apparently healthy. Subjects with significant medical history or who were taking any medications were excluded. RESULTS: Separate reference intervals for boys and girls were required for 33% of the groups. Aldolase showed gender variation in the 6-8, 12-14, and 15-17 y. Amylase was the only analyte that showed no significant gender differences within any age group. Both ceruloplasmin and uric acid had significant differences between the 12-14 and 15-17 y groups. Creatine kinase exhibited statistically significant gender differences in all age groups with the exception of 6-8 y. CONCLUSION: We verified that when establishing pediatric reference intervals, partitioning by age and gender is frequently necessary.