Langerhans cell histiocytosis: NACHO update on progress, chaos, and opportunity on the path to rational cures.

Langerhans cell histiocytosis (LCH) is a myeloid neoplastic disorder characterized by lesions with CD1a-positive/Langerin (CD207)-positive histiocytes and inflammatory infiltrate that can cause local tissue damage and systemic inflammation. Clinical presentations range from single lesions with minimal impact to life-threatening disseminated disease. Therapy for systemic LCH has been established through serial trials empirically testing different chemotherapy agents and durations of therapy. However, fewer than 50% of patients who have disseminated disease are cured with the current standard-of-care vinblastine/prednisone/(mercaptopurine), and treatment failure is associated with long-term morbidity, including the risk of LCH-associated neurodegeneration. Historically, the nature of LCH-whether a reactive condition versus a neoplastic/malignant condition-was uncertain. Over the past 15 years, seminal discoveries have broadly defined LCH pathogenesis; specifically, activating mitogen-activated protein kinase pathway mutations (most frequently, BRAFV600E) in myeloid precursors drive lesion formation. LCH therefore is a clonal neoplastic disorder, although secondary inflammatory features contribute to the disease. These paradigm-changing insights offer a promise of rational cures for patients based on individual mutations, clonal reservoirs, and extent of disease. However, the pace of clinical trial development behind lags the kinetics of translational discovery. In this review, the authors discuss the current understanding of LCH biology, clinical characteristics, therapeutic strategies, and opportunities to improve outcomes for every patient through coordinated agent prioritization and clinical trial efforts.

Neutrophil gelatinase-associated lipocalin is elevated in children with acute kidney injury and sickle cell anemia, and predicts mortality.

Urine neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of acute kidney injury that has been adapted to a urine dipstick test. However, there is limited data on its use in low-and-middle-income countries where diagnosis of acute kidney injury remains a challenge. To study this, we prospectively enrolled 250 children with sickle cell anemia aged two to 18 years encompassing 185 children hospitalized with a vaso-occlusive pain crisis and a reference group of 65 children attending the sickle cell clinic for routine care follow up. Kidney injury was defined using serial creatinine measures and a modified-Kidney Disease Improving Global Outcome definition for sickle cell anemia. Urine NGAL was measured using the NGAL dipstick and a laboratory reference. The mean age of children enrolled was 8.9 years and 42.8% were female. Among hospitalized children, 36.2% had kidney injury and 3.2% died. Measured urine NGAL levels by the dipstick were strongly correlated with the standard enzyme-linked immunosorbent assay for urine NGAL (hospitalized children, 0.71; routine care reference, 0.88). NGAL levels were elevated in kidney injury and significantly increased across injury stages. Hospitalized children with a high-risk dipstick test (300ng/mL and more) had a 2.47-fold relative risk of kidney injury (95% confidence interval 1.68 to 3.61) and 7.28 increased risk of death (95% confidence interval 1.10 to 26.81) adjusting for age and sex. Thus, urine NGAL levels were found to be significantly elevated in children with sickle cell anemia and acute kidney injury and may predict mortality.

Acute kidney injury in hospitalized children with sickle cell anemia.

BACKGROUND: Children with sickle cell anemia (SCA) are at increased risk of acute kidney injury (AKI) that may lead to death or chronic kidney disease. This study evaluated AKI prevalence and risk factors in children with SCA hospitalized with a vaso-occlusive crisis (VOC) in a low-resource setting. Further, we evaluated whether modifications to the Kidney Disease: Improving Global Outcomes (KDIGO) definition would influence clinical outcomes of AKI in children with SCA hospitalized with a VOC. METHODS: We prospectively enrolled 185 children from 2 - 18 years of age with SCA (Hemoglobin SS) hospitalized with a VOC at a tertiary hospital in Uganda. Kidney function was assessed on admission, 24-48 h of hospitalization, and day 7 or discharge. Creatinine was measured enzymatically using an isotype-dilution mass spectrometry traceable method. AKI was defined using the original-KDIGO definition as ≥ 1.5-fold change in creatinine within seven days or an absolute change of ≥ 0.3 mg/dl within 48 h. The SCA modified-KDIGO (sKDIGO) definition excluded children with a 1.5-fold change in creatinine from 0.2 mg/dL to 0.3 mg/dL. RESULTS: Using KDIGO, 90/185 (48.7%) children had AKI with 61/185 (33.0%) AKI cases present on admission, and 29/124 (23.4%) cases of incident AKI. Overall, 23 children with AKI had a 1.5-fold increase in creatinine from 0.2 mg/dL to 0.3 m/dL. Using the sKDIGO-definition, 67/185 (36.2%) children had AKI with 43/185 (23.2%) cases on admission, and 24/142 (16.9%) cases of incident AKI. The sKDIGO definition, but not the original-KDIGO definition, was associated with increased mortality (0.9% vs. 7.5%, p = 0.024). Using logistic regression, AKI risk factors included age (aOR, 1.10, 95% CI 1.10, 1.20), hypovolemia (aOR, 2.98, 95% CI 1.08, 8.23), tender hepatomegaly (aOR, 2.46, 95% CI 1.05, 5.81), and infection (aOR, 2.63, 95% CI 1.19, 5.81) (p < 0.05). CONCLUSION: These results demonstrate that AKI is a common complication in children with SCA admitted with VOC. The sKDIGO definition of AKI in children with SCA was a better predictor of clinical outcomes in children. There is need for promotion of targeted interventions to ensure early identification and treatment of AKI in children with SCA.

Genetic errors of immunity distinguish pediatric nonmalignant lymphoproliferative disorders.

BACKGROUND: Pediatric nonmalignant lymphoproliferative disorders (PLPDs) are clinically and genetically heterogeneous. Long-standing immune dysregulation and lymphoproliferation in children may be life-threatening, and a paucity of data exists to guide evaluation and treatment of children with PLPD. OBJECTIVE: The primary objective of this study was to ascertain the spectrum of genomic immunologic defects in PLPD. Secondary objectives included characterization of clinical outcomes and associations between genetic diagnoses and those outcomes. METHODS: PLPD was defined by persistent lymphadenopathy, lymph organ involvement, or lymphocytic infiltration for more than 3 months, with or without chronic or significant Epstein-Barr virus (EBV) infection. Fifty-one subjects from 47 different families with PLPD were analyzed using whole exome sequencing. RESULTS: Whole exome sequencing identified likely genetic errors of immunity in 51% to 62% of families (53% to 65% of affected children). Presence of a genetic etiology was associated with younger age and hemophagocytic lymphohistiocytosis. Ten-year survival for the cohort was 72.4%, and patients with viable genetic diagnoses had a higher survival rate (82%) compared to children without a genetic explanation (48%, P = .03). Survival outcomes for individuals with EBV-associated disease and no genetic explanation were particularly worse than outcomes for subjects with EBV-associated disease and a genetic explanation (17% vs 90%; P = .002). Ascertainment of a molecular diagnosis provided targetable treatment options for up to 18 individuals and led to active management changes for 12 patients. CONCLUSIONS: PLPD defines children at high risk for mortality, and whole exome sequencing informs clinical risks and therapeutic opportunities for this diagnosis.

Transient bone marrow hypoplasia preceding T-Cell acute lymphoblastic leukemia: a case report.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy and is characterised by hyperproliferation of malignant lymphocytes in the bone marrow. Rarely, ALL may be preceded by a period of pancytopenia and bone marrow hypoplasia which spontaneously recovers. This phenomenon, which has not before been described in T-cell ALL, is referred to as transient bone marrow hypoplasia. CASE PRESENTATION: A 5-year-old boy who presented with high-grade fever and generalised lymphadenopathy, was found to have pancytopenia on peripheral blood count and bone marrow hypoplasia. He was observed over a one-month period during which his bone marrow and peripheral blood counts recovered spontaneously. Symptoms recurred after 4 months and he was found to have blast infiltration of the bone marrow and diagnosed with T-cell ALL. CONCLUSION: Cases of transient bone marrow hypoplasia or overt aplastic anemia with spontaneous recovery and then followed by B-cell ALL or Acute Myeloid Leukemia have been described previously in the medical literature. This is the first case of transient bone marrow hypoplasia resulting into ALL of T-cell immunophenotype. While marrow hypoplasia preceding ALL remains poorly understood, it suggests an antecedent environmental insult to lymphoid progenitors or a germline abnormality that predisposes to lymphoid dysplasia. This may provide clues to the hitherto unknown pathophysiological process and etiological factors that precede the majority of childhood ALL cases. This case enlightens pediatricians about the existence of such rare cases so as to periodically follow up children with pancytopenia and/or bone marrow hypoplasia for prolonged periods even after apparent recovery.

Association of race and ethnicity with clinical phenotype, genetics, and survival in pediatric acute myeloid leukemia.

Black and Hispanic children with acute myeloid leukemia (AML) have worse outcomes compared with White children. AML is a heterogeneous disease with numerous genetic subtypes in which these disparities have not been specifically investigated. In this study, we used the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database to examine the association of race-ethnicity with leukemia cytogenetics, clinical features, and survival outcomes within major cytogenetic subgroups of pediatric AML. Compared with White non-Hispanic patients, t(8;21) AML was more prevalent among Black (odds ratio [OR], 2.22; 95% confidence interval [CI], 1.28-3.74) and Hispanic patients (OR, 1.74; 95% CI, 1.05-2.83). The poor prognosis KMT2A rearrangement t(6;11)(q27;q23) was more prevalent among Black patients (OR, 6.12; 95% CI, 1.81-21.59). Among those with KMT2Ar AML, Black race was associated with inferior event-free survival (EFS) (hazard ratio [HR], 2.31; 95% CI, 1.41-3.79) and overall survival (OS) (HR, 2.54; 1.43-4.51). Hispanic patients with KMT2Ar AML also had inferior EFS (HR, 2.20; 95% CI, 1.27-3.80) and OS (HR, 2.07; 95% CI, 1.09-3.93). Similarly, among patients with t(8;21) or inv(16) AML (ie, core-binding factor [CBF] AML), Black patients had inferior outcomes (EFS HR, 1.93; 95% CI, 1.14-3.28 and OS HR, 3.24; 95% CI, 1.60-6.57). This disparity was not detected among patients receiving gemtuzumab ozogamicin (GO). In conclusion, racial-ethnic disparities in survival outcomes among young people with AML are prominent and vary across cytogenetic subclasses. Future studies should explore the socioeconomic and biologic determinants of these disparities.

IFN-γ signature in the plasma proteome distinguishes pediatric hemophagocytic lymphohistiocytosis from sepsis and SIRS.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome characterized by pathologic immune activation in which prompt recognition and initiation of immune suppression is essential for survival. Children with HLH have many overlapping clinical features with critically ill children with sepsis and systemic inflammatory response syndrome (SIRS) in whom alternative therapies are indicated. To determine whether plasma biomarkers could differentiate HLH from other inflammatory conditions and to better define a core inflammatory signature of HLH, concentrations of inflammatory plasma proteins were compared in 40 patients with HLH to 47 pediatric patients with severe sepsis or SIRS. Fifteen of 135 analytes were significantly different in HLH plasma compared with SIRS/sepsis, including increased interferon-γ (IFN-γ)-regulated chemokines CXCL9, CXCL10, and CXCL11. Furthermore, a 2-analyte plasma protein classifier including CXCL9 and interleukin-6 was able to differentiate HLH from SIRS/sepsis. Gene expression in CD8+ T cells and activated monocytes from blood were also enriched for IFN-γ pathway signatures in peripheral blood cells from patients with HLH compared with SIRS/sepsis. This study identifies differential expression of inflammatory proteins as a diagnostic strategy to identify critically ill children with HLH, and comprehensive unbiased analysis of inflammatory plasma proteins and global gene expression demonstrates that IFN-γ signaling is uniquely elevated in HLH. In addition to demonstrating the ability of diagnostic criteria for HLH and sepsis or SIRS to identify groups with distinct inflammatory patterns, results from this study support the potential for prospective evaluation of inflammatory biomarkers to aid in diagnosis of and optimizing therapeutic strategies for children with distinctive hyperinflammatory syndromes.

Association between Antiretroviral Therapy and Cancers among Children Living with HIV in Sub-Saharan Africa.

Approximately 91% of the world's children living with HIV (CLWH) are in sub-Saharan Africa (SSA). Living with HIV confers a risk of developing HIV-associated cancers. To determine the incidence and risk factors for cancer among CLWH, we conducted a nested case-control study of children 0-18 years from 2004-2014 at five centers in four SSA countries. Incident cases of cancer and HIV were frequency-matched to controls with HIV and no cancer. We calculated the incidence density by cancer type, logistic regression, and relative risk to evaluate risk factors of cancer. The adjusted incidence density of all cancers, Kaposi sarcoma, and lymphoma were 47.6, 36.6, and 8.94 per 100,000 person-years, respectively. Delayed ART until after 2 years of age was associated with cancer (OR = 2.71, 95% CI 1.51, 4.89) even after adjusting for World Health Organization clinical stage at the time of enrolment for HIV care (OR = 2.85, 95% CI 1.57, 5.13). The relative risk of cancer associated with severe CD4 suppression was 6.19 (p = 0.0002), 2.33 (p = 0.0042), and 1.77 (p = 0.0305) at 1, 5, and 10 years of ART, respectively. The study demonstrates the high risk of cancers in CLWH and the potential benefit of reducing this risk by the early initiation of ART.

Association of Rituximab Use With Adverse Events in Children, Adolescents, and Young Adults.

Importance: Rituximab is among the most frequently used immunotherapies in pediatrics. Few studies have reported long-term adverse events associated with its use for children. Objective: To describe the use of rituximab and to assess whether its use is associated with short- or long-term adverse events, infections, or time to immune reconstitution in a diverse group of young people. Design, Setting, and Participants: This retrospective cohort study included 468 patients aged younger than 21 years who received rituximab for diverse indications between October 1, 2010, and December 31, 2017, at Texas Children's Hospital, a large pediatric referral hospital. Patterns of adverse events, infections, and immune recovery are described. Data analyses were conducted from December 2019 to June 2020. Exposure: One or more doses of rituximab. Main Outcomes and Measures: Adverse drug events (eg, anaphylaxis), incidence of mild and severe infections, and time to recovery of B lymphocyte subset counts and immunoglobulin levels. Survival models and logistic regression analyses and were used to identify associated risk factors of infectious and noninfectious adverse drug events. Results: We identified 468 patients receiving at least 1 dose of rituximab. The total follow-up time was 11 713 person-months. Of the 468 patients, 293 (62.6%) were female, the median (interquartile range) age at receipt of dose was 14.3 (9.9-16.8) years, and 209 (44.7%) were self-reported White Hispanic. Adverse events associated with rituximab infusion occurred in 72 patients (15.4%), and anaphylaxis occurred in 17 patients (3.6%). Long-term adverse events, such as prolonged neutropenia and leukoencephalopathy, were absent. Infections occurred in 224 patients (47.9%); 84 patients (17.9%) had severe infections, and 3 patients (0.6%) had lethal infections. Concurrent use of intravenous chemotherapy, treatment of systemic lupus erythematosus, neutropenia, and use of intravenous immunoglobulin were associated with increased risk of infection. Among 135 patients (28.8%) followed up to B cell count recovery, CD19+ or CD20+ cell numbers normalized in a median of 9.0 months (interquartile range, 5.9-14.4 months) following rituximab use; 48 of 95 patients (51%) evaluated beyond a year had low-for-age B cell counts. Recovery of CD27+ memory B cell number occurred in a median of 15.7 months (interquartile range, 6.0-22.7 months). Among patients with normal baseline values, low immunoglobulin G (IgG) levels developed in 67 of 289 patients (23.2%) and low IgM levels in 118 of 255 patients (40.8%); of these patients evaluated beyond 12 months from rituximab, 16 of 117 (13.7%) had persistently low IgG and 37 (33.9%) of 109 had persistently low IgM. Conclusions and Relevance: Rituximab is well tolerated among young people and is associated with few serious adverse events, but infections are common, corresponding to a prolonged period of B cell count recovery often lasting for longer than a year. Further examination of strategies to prevent infections following rituximab should be pursued.

Global health disparities in childhood cancers.

PURPOSE OF REVIEW: The high cure rates of children with cancer in high-income countries (HICs) are due to the impact of biomedical innovations on children with highly fatal diseases. We discuss why these innovations have not benefitted most children with cancer globally and propose broad strategies to reduce these disparities. RECENT FINDINGS: Over 85% of children with cancer in HIC are cured while less than 20% in many low-income countries survive the disease. Hence, childhood cancer survival is poor globally since over 80% of children with cancer live in low-income and middle-income countries (LMICs). Inadequate skilled workforce and health infrastructure across all disciplines of pediatrics in LMIC are the main reasons for these disparities. Although biological differences may contribute to these disparities as well, many are unconfirmed because they are confounded by differences in referral patterns and clinical capacity. HIC partnerships with LMIC that focus on locally based pediatrics training and clinical infrastructure building are beginning to close the gap. SUMMARY: Pediatric oncology is symbolic of the significant disparities in childhood survival arising from poverty, inadequate pediatric infrastructure, and skilled workforce in LMIC. Partnerships with HIC that build multidisciplinary pediatrics capacity and clinical infrastructure are beginning to make transformative improvements.

Defining the Inflammatory Plasma Proteome in Pediatric Hodgkin Lymphoma.

Hodgkin lymphoma (HL) histopathology is characterized by rare malignant Reed-Sternberg cells among an inflammatory infiltrate. We hypothesized that characteristics of inflammation in pediatric HL lesions would be reflected by the levels of inflammatory cytokines or chemokines in pre-therapy plasma of children with HL. The study objectives were to better define the inflammatory pre-therapy plasma proteome and identify plasma biomarkers associated with extent of disease and clinical outcomes in pediatric HL. Pre-therapy plasma samples were obtained from pediatric subjects with newly diagnosed HL and healthy pediatric controls. Plasma concentrations of 135 cytokines/chemokines were measured with the Luminex platform. Associations between protein concentration and disease characteristics were determined using multivariate permutation tests with false discovery control. Fifty-six subjects with HL (mean age: 13 years, range 3-18) and 47 controls were analyzed. The cytokine/chemokine profiles of subjects with HL were distinct from controls, and unique cytokines/chemokines were associated with high-risk disease (IL-10, TNF-α, IFN-γ, IL-8) and slow early response (CCL13, IFN-λ1, IL-8). TNFSF10 was significantly elevated among those who ultimately relapsed and was significantly associated with worse event-free survival. These biomarkers could be incorporated into biologically based risk stratification to optimize outcomes and minimize toxicities in pediatric HL.

Five decades of low intensity and low survival: adapting intensified regimens to cure pediatric Burkitt lymphoma in Africa.

Long-term cure of childhood Burkitt lymphoma (BL) in sub-Saharan Africa after treatment with single-agent cyclophosphamide has been documented for more than half of a century. Contemporary cure rates for the highest-risk patients with BL in high-income countries exceed 90% using intensive multiagent chemotherapy. By contrast, the majority of African children with BL still die. Data spanning 5 decades in Africa have repeatedly shown that the children most likely to achieve cure with limited cyclophosphamide regimens are those with lower-stage disease isolated to the jaw. Attempts to intensify the cyclophosphamide monotherapy backbone with the addition of vincristine, low-dose methotrexate, prednisone, doxorubicin, and/or low-dose cytarabine have not yielded significant improvement. High-dose methotrexate is a critical component in the treatment of childhood BL worldwide. Although initial efforts in Africa to incorporate high-dose methotrexate resulted in high treatment-related mortality, more recent collaborative experiences from North and West Africa, as well as Central America, demonstrate that it can be administered safely and effectively, despite limitations in supportive care resources. Recognizing the unacceptable disparity in curative outcomes for BL between the United States/Europe and equatorial Africa, there is a critical need to safely adapt contemporary treatment regimens to optimize curative outcomes amid the resource limitations in regions where BL is endemic. Here, we critically review reports of BL treatment outcomes from low- and middle-income countries, in addition to data from high-income countries that predated modern intensified regimens, to identify potential strategies to improve the therapeutic approach for children suffering from BL in sub-Saharan Africa.

Association of population mixing and acute lymphocytic leukemia in children and young adults.

BACKGROUND: The association of population mixing (PM1) with childhood acute lymphocytic leukemia (ALL2) has been reproduced in multiple studies. However, the mechanism underlying this association is unknown. METHODS: Ecological study of incidence of pediatric ALL among 253 counties in the State of Texas (USA) using surrogates of genetic and environmental PM. ALL incidence data were obtained from Texas Cancer Registry and county population statistics from the US Census Bureau. Poisson regression was used to compare ALL incidence and PM. RESULTS: There is substantial and variable genetic and environmental PM among counties in Texas. Indicators of genetic PM including proportion of multiracial households, ratio of Hispanics to non-Hispanics, and ratio of foreign to native-born residents were all significantly associated with a higher incidence of ALL (IRR3 1.81 (95CI 1.05-3.13), 1.67 (95CI 1.16-2.37), and 1.59 (95CI 1.03-2.48), respectively). Surrogates of environmental PM namely population density and persons per household were not associated with incidence of ALL; IRRs 1.29 (95CI 0.4-4.15) and 1.47 (95CI 0.89-2.43). CONCLUSIONS: These findings are consistent with prior patterns and magnitudes of PM association with ALL. Our findings suggest that the implicated mechanism of leukemogenesis in PM may be genetically transmitted rather than environmental.

Global Disparities in Wilms Tumor.

BACKGROUND: Wilms tumor accounts for more than 90% of all malignant kidney neoplasms in children. Survival after diagnosis and treatment is excellent in most high-income countries. Low- and middle-income countries (LMICs) continue to struggle with Wilms tumor detection and treatment. The purpose of this study was to compare the global incidence and outcomes of Wilms tumor. MATERIAL AND METHODS: Wilms tumor incidence data from the World Health Organization (WHO), International Incidence of Childhood Cancer, Volume III, was analyzed according to world region and country socioeconomic status using descriptive statistics and independent-sample Kruskal-Wallis Test. A literature review was also performed to assess outcomes and identify common themes. RESULTS: Wilms tumor was most common in children aged 0-4 y (median incidence 15.1 [IQR 11.8-18.7] ASR/million). High-income countries reported significantly higher median incidence than middle-income countries (8.6 [7.4-9.3] versus 6.1 [4.9-8.7] ASR/million; P < 0.01), although low-income countries reported the highest median incidence overall (9.8 [6.2-16.4] ASR/million). Low-income countries had the fewest countries with registries (n = 6). Overall survival ranged from 70% to 97% in high-income countries, 61%-94% in upper-middle-income countries, 0%-85% in lower-middle-income countries, and 25%-53% in low-income countries. Delay in diagnosis, lack of available treatment, and inadequate follow up contributed to the large variations in outcomes. CONCLUSIONS: Reported Wilms tumor incidence is highest in low-income countries, and these are also the countries that have the lowest survival. Lack of significance may reflect incomplete and absent data reporting from lower income countries. Accurate and comprehensive registries are the first steps to appropriate resource allocation in order to improve outcomes for this highly curable childhood malignancy.

CNS Langerhans cell histiocytosis: Common hematopoietic origin for LCH-associated neurodegeneration and mass lesions.

BACKGROUND: Central nervous system Langerhans cell histiocytosis (CNS-LCH) brain involvement may include mass lesions and/or a neurodegenerative disease (LCH-ND) of unknown etiology. The goal of this study was to define the mechanisms of pathogenesis that drive CNS-LCH. METHODS: Cerebrospinal fluid (CSF) biomarkers including CSF proteins and extracellular BRAFV600E DNA were analyzed in CSF from patients with CNS-LCH lesions compared with patients with brain tumors and other neurodegenerative conditions. Additionally, the presence of BRAFV600E was tested in peripheral mononuclear blood cells (PBMCs) as well as brain biopsies from LCH-ND patients, and the response to BRAF-V600E inhibitor was evaluated in 4 patients with progressive disease. RESULTS: Osteopontin was the only consistently elevated CSF protein in patients with CNS-LCH compared with patients with other brain pathologies. BRAFV600E DNA was detected in CSF of only 2/20 (10%) cases, both with LCH-ND and active lesions outside the CNS. However, BRAFV600E+ PBMCs were detected with significantly higher frequency at all stages of therapy in LCH patients who developed LCH-ND. Brain biopsies of patients with LCH-ND demonstrated diffuse perivascular infiltration by BRAFV600E+ cells with monocyte phenotype (CD14+ CD33+ CD163+ P2RY12- ) and associated osteopontin expression. Three of 4 patients with LCH-ND treated with BRAF-V600E inhibitor experienced significant clinical and radiologic improvement. CONCLUSION: In LCH-ND patients, BRAFV600E+ cells in PBMCs and infiltrating myeloid/monocytic cells in the brain is consistent with LCH-ND as an active demyelinating process arising from a mutated hematopoietic precursor from which LCH lesion CD207+ cells are also derived. Therapy directed against myeloid precursors with activated MAPK signaling may be effective for LCH-ND. Cancer 2018;124:2607-20. © 2018 American Cancer Society.

Evaluation of maternal and perinatal characteristics on childhood lymphoma risk: A population-based case-control study.

BACKGROUND: Lymphoma is one of the most common pediatric malignancies; however, there are few well-established risk factors. Therefore, we investigated if maternal and perinatal characteristics influenced the risk of childhood lymphoma. PROCEDURE: Information on cases (n = 374) diagnosed with lymphoma and born in Texas for the period 1995-2011 was obtained from the Texas Cancer Registry. Birth certificate controls were randomly selected at a ratio of 10 controls per 1 case for the same period of 1995-2011. Unconditional logistic regression was used to generate unadjusted (OR) and adjusted odds ratios (aOR) and 95% confidence intervals (CI) for the following histologic subtypes: Hodgkin (HL), Burkitt (BL), and non-BL non-HLs (non-BL NHLs). RESULTS: Overall, our findings indicate specific maternal and perinatal characteristics influence childhood lymphoma risk. Mexico-born mothers were more likely to have offspring who developed BL compared to mothers born in the United States (U.S.; aOR: 2.15; 95% CI: 1.06-4.36). Further, mothers who resided at time of delivery in a county on the U.S.-Mexico border were more likely to give birth to offspring who developed non-BL NHL (aOR: 1.72; 95% CI: 1.11-2.67) compared to mothers not living on the U.S.-Mexico border at time of infant birth. Last, infants born large-for-gestational-age experienced a twofold increase in BL risk (aOR: 2.00; 95% CI: 1.10-3.65). CONCLUSIONS: In this population-based assessment, we confirmed previously reported risk predictors of childhood lymphoma, including sex of infant, while highlighting novel risk factors that warrant assessment in future studies.

Mapping the Epidemiology of Kaposi Sarcoma and Non-Hodgkin Lymphoma Among Children in Sub-Saharan Africa: A Review.

Children with human immunodeficiency virus (HIV) have an increased risk of developing Kaposi Sarcoma (KS) and non-Hodgkin lymphoma (NHL) compared to HIV-negative children. We compiled currently published epidemiologic data on KS and NHL among children in sub-Saharan Africa (SSA). Among countries with available data, the median incidence of KS was 2.05/100,000 in the general pediatric population and 67.35/100,000 among HIV-infected children. The median incidence of NHL was 1.98/100,000 among the general pediatric population, while data on NHL incidence among HIV-infected children were lacking. Larger regional studies are needed to better address the dearth of epidemiologic information on pediatric KS and NHL in SSA.