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Endemic Burkitt lymphoma (BL) was publically described in 1958 and remains the most prevalent pediatric cancer in equatorial Africa with an annual incidence between two and five cases per 100,000 children. Several risk factors have been identified, including early-age infection with Epstein-Barr virus, a geographic association with high Plasmodium falciparum malaria transmission, and poor nutrition. However, other modifiable factors play a role in the survival of these children. Treatment regimens for BL have evolved over a time period that spans nearly 50 years. This review will compare survival between different combination chemotherapeutic regimens and discuss other key determinants of outcomes among children diagnosed with BL in resource-limited settings. A discussion of obstacles to diagnosis will be presented, including low community awareness of pediatric cancer, limited access to health facilities, inaccurate or delayed diagnosis often beginning at lower level health rural facilities that are typically staffed by those with limited training in oncology, and insufficient pathology support to confirm diagnosis. Other challenges examined here include those related to treatment adherence, specifically the social and economic stressors that can lead to abandonment of care, and treatment-related toxicity, a challenge compounded not only by the scarcity of medications for supportive care, but also the paucity of clinically trained medical professionals available to manage integrated care for these children. Future directions for enhancing BL survival will be discussed including molecular approaches for rational drug discovery as well as the benefits of forming a unified, global BL research network. [ABSTRACT FROM AUTHOR]

Background: In South Africa in 2010, about 340,000 children under the age of 15 were infected with HIV. We describe the increase in the treatment of South African pediatric HIV-infected patients assisted by the President's Emergency Plan for AIDS Relief (PEPFAR) from 2004 to 2010. Methods: We reviewed routine program data from PEPFAR-funded implementing partners among persons receiving antiretroviral treatment age 15 years old and less. Data quality was assessed during the reporting period by program officials through routine analysis of trends and logic checks. Based on UNAIDS estimated mortality rates of untreated HIV-infected children, we calculated the number of deaths averted and life-years gained in children under five receiving PEPFAR-assisted antiretroviral treatment. Results: From October 2004 through September 2010, the number of children newly initiated on antiretroviral treatment in PEPFAR-assisted programs increased from 154 to 2,641 per month resulting in an increase from 2,412 children on antiretroviral treatment in September 2005 to 79,416 children in September 2010. Of those children who initiated antiretroviral treatment before September 2009, 0-4 year olds were 1.4 (95% CI: 1.3-1.5) times as likely to transfer out of the program or die as 5-14 year olds; males were 1.3 (95% CI: 1.0-1.7) times as likely to stop treatment as females. Approximately 27,548 years of life were added to children under-five years old from PEPFAR-assisted antiretroviral treatment. Conclusions: Pediatric antiretroviral treatment in South Africa has increased substantially. However, additional case-finding and a further acceleration in the implementation of pediatric care and treatment services is required to meet the current treatment need. [ABSTRACT FROM AUTHOR]

CTLA-4 is a key factor in regulating and maintaining self tolerance, providing a negative signal to the T cell and thus limiting immune responses. Several polymorphisms within the CTLA-4 gene have been associated with an increased risk of developing autoimmune diseases and, very recently, with susceptibility to human cancer. Acute lymphoblastic leukemia is a clonal disorder of lymphoid progenitors representing the most frequent malignancy of childhood. Here, we show the presence at significantly elevated levels of a circulating soluble form of CTLA-4 in 70% of B-ALL pediatric patients with active disease, the positive correlation between the percentage of leukemic B lymphocytes and the amount of serum sCTLA-4, and the expression of sCTLA-4 transcript by B cells in patients. Finally, a correlation between CD1d expression (a negative prognostic marker) and the sCTLA-4 in B-ALL patients was observed. This suggests a possible role of this soluble molecule as a marker of progression or severity of the neoplastic disease. [ABSTRACT FROM AUTHOR]

Background: Recent evidence suggests that lipid pathway is altered in many human tumours. In Burkitt lymphoma this is reflected by the presence of lipid droplets which are visible in the cytoplasm of neoplastic cells in cytological preparations. These vacuoles are not identifiable in biopsy section as lipids are "lost" during tissue processing. Methods and Results: In this study we investigated the expression of genes involved in lipid metabolism, at both RNA and protein level in Burkitt lymphoma and in other B-cell aggressive lymphoma cases. Gene expression profile indicated a significant over-expression of the adipophilin gene and marked up-regulation of other genes involved in lipid metabolism in Burkitt lymphoma. These findings were confirmed by immunohistochemistry on a series od additional histological samples: 45 out of 47 BL cases showed strong adipophilin expression, while only 3 cases of the 33 of the not-Burkitt lymphoma category showed weak adipophilin expression (p<0.05). Conclusions: Our preliminary results suggest that lipid metabolism is altered in BL, and this leads to the accumulation of lipid vacuoles. These vacuoles may be specifically recognized by a monoclonal antibody against adipophilin, which may therefore be a useful marker for Burkitt lymphoma because of its peculiar expression pattern. Moreover this peptide might represent an interesting candidate for interventional strategies. [ABSTRACT FROM AUTHOR]

Introduction: Iron deficiency is highly prevalent in pre-school children in developing countries and an important health problem in sub-Saharan Africa. A debate exists on the possible protective effect of iron deficiency against malaria and other infections; yet consensus is lacking due to limited data. Recent studies have focused on the risks of iron supplementation but the effect of an individual's iron status on malaria risk remains unclear. Studies of iron status in areas with a high burden of infections often are exposed to bias. The aim of this study was to assess the predictive value of baseline iron status for malaria risk explicitly taking potential biases into account. Methods and materials: We prospectively assessed the relationship between baseline iron deficiency (serum ferritin <30 µg/L) and malaria risk in a cohort of 727 Malawian preschool children during a year of follow-up. Data were analyzed using marginal structural Cox regression models and confounders were selected using causal graph theory. Sensitivity of results to bias resulting from misclassification of iron status by concurrent inflammation and to bias from unmeasured confounding were assessed using modern causal inference methods. Results and Conclusions: The overall incidence of malaria parasitemia and clinical malaria was 1.9 (95% CI 1.8-2.0) and 0.7 (95% CI 0.6-0.8) events per person-year, respectively. Children with iron deficiency at baseline had a lower incidence of malaria parasitemia and clinical malaria during a year of follow- up; adjusted hazard ratio's 0.55 (95%-CI:0.41-0.74) and 0.49 (95%-CI:0.33-0.73), respectively. Our results suggest that iron deficiency protects against malaria parasitemia and clinical malaria in young children. Therefore the clinical importance of treating iron deficiency in a pre-school child should be weighed carefully against potential harms. In malaria endemic areas treatment of iron deficiency in children requires sustained prevention of malaria. [ABSTRACT FROM AUTHOR]

Background: The 19 kDa C-terminal region of Plasmodium falciparum Merozoite Surface Protein-1 is a known target of naturally acquired humoral immunity and a malaria vaccine candidate. MSP-119 has four predominant haplotypes resulting in amino acid changes labelled EKNG, QKNG, QTSR and ETSR. IgG antibodies directed against all four variants have been detected, but it is not known if these variant specific antibodies are associated with haplotype-specific protection from infection. Methods: Blood samples from 201 healthy Kenyan adults and children who participated in a 12-week treatment time-to-infection study were evaluated. Venous blood drawn at baseline (week 0) was examined for functional and serologic antibodies to MSP-119 and MSP-142 variants. MSP-119 haplotypes were detected by a multiplex PCR assay at baseline and weekly throughout the study. Generalized linear models controlling for age, baseline MSP-119 haplotype and parasite density were used to determine the relationship between infecting P. falciparum MSP-119 haplotype and variant-specific antibodies. Results: A total of 964 infections resulting in 1,533 MSP-119 haplotypes detected were examined. The most common haplotypes were EKNG and QKNG, followed by ETSR and QTSR. Children had higher parasite densities, greater complexity of infection (>1 haplotype), and more frequent changes in haplotypes over time compared to adults. Infecting MSP-119 haplotype at baseline (week 0) had no influence on haplotypes detected over the subsequent 11 weeks among children or adults. Children but not adults with MSP-119 and some MSP-142 variant antibodies detected by serology at baseline had delayed time-to-infection. There was no significant association of variant-specific serology or functional antibodies at baseline with infecting haplotype at baseline or during 11 weeks of follow up among children or adults. Conclusions: Variant transcending IgG antibodies to MSP-119 are associated with protection from infection in children, but not adults. These data suggest that inclusion of more than one MSP-119 variant may not be required in a malaria blood stage vaccine. [ABSTRACT FROM AUTHOR]

Endemic Burkitt's lymphoma is the most common childhood cancer in equatorial Africa. Two ubiquitous human pathogens are thought to be responsible for the aetiology of this disease: Epstein–Barr virus and Plasmodium falciparum malaria. New data suggest how these two pathogens might interact to result in disease and provide insights into the emerging concepts of polymicrobial disease pathogenesis. [ABSTRACT FROM AUTHOR]

Simple Summary: Endemic Burkitt lymphoma (eBL) is a common pediatric cancer in sub-Saharan Africa. The incidence of this aggressive B-cell cancer is linked to Plasmodium falciparum (Pf) malaria and Epstein–Barr virus (EBV) co-infections during childhood. Most eBL tumors contain EBV and are characterized by the Epstein–Barr Nuclear Antigen 1 (EBNA1) latency I pattern of viral gene expression. The aim of our study was to compare the phenotypes and functions of CD4+ and CD8+ T cell responses to EBNA1 in children diagnosed with eBL and in healthy EBV-seropositive children to highlight differences that contribute to the balance between anti-viral immunity and eBL pathogenesis. Children diagnosed with endemic Burkitt lymphoma (eBL) are deficient in interferon-γ (IFN-γ) responses to Epstein–Barr Nuclear Antigen1 (EBNA1), the viral protein that defines the latency I pattern in this B cell tumor. However, the contributions of immune-regulatory cytokines and phenotypes of the EBNA1-specific T cells have not been characterized for eBL. Using a bespoke flow cytometry assay we measured intracellular IFN-γ, IL-10, IL-17A expression and phenotyped CD4+ and CD8+ T cell effector memory subsets specific to EBNA1 for eBL patients compared to two groups of healthy children with divergent malaria exposures. In response to EBNA1 and a malaria antigen (PfSEA-1A), the three study groups exhibited strikingly different cytokine expression and T cell memory profiles. EBNA1-specific IFN-γ-producing CD4+ T cell response rates were lowest in eBL (40%) compared to children with high malaria (84%) and low malaria (66%) exposures (p < 0.0001 and p = 0.0004, respectively). However, eBL patients did not differ in CD8+ T cell response rates or the magnitude of IFN-γ expression. In contrast, eBL children were more likely to have EBNA1-specific CD4+ T cells expressing IL-10, and less likely to have polyfunctional IFN-γ+IL-10+ CD4+ T cells (p = 0.02). They were also more likely to have IFN-γ+IL-17A+, IFN-γ+ and IL-17A+ CD8+ T cell subsets compared to healthy children. Cytokine-producing T cell subsets were predominantly CD45RA+CCR7+ TNAIVE-LIKE cells, yet PD-1, a marker of persistent activation/exhaustion, was more highly expressed by the central memory (TCM) and effector memory (TEM) T cell subsets. In summary, our study suggests that IL-10 mediated immune regulation and depletion of IFN-γ+ EBNA1-specific CD4+ T cells are complementary mechanisms that contribute to impaired T cell cytotoxicity in eBL pathogenesis. [ABSTRACT FROM AUTHOR]

The WHO recommends hepatitis B birth‐dose vaccination (HepB‐BD), but it is not routinely given in most sub‐Saharan African countries. We aimed to assess the immunogenicity of HepB‐BD in addition to the existing hepatitis B vaccine (HepB3) schedule in Kinshasa, Democratic Republic of Congo among HBV‐unexposed and HBV‐exposed infants. Using an open‐label, randomised, controlled design, HBV‐unexposed infants were randomised (1:1) to receive the standard HepB3 vaccine series (group U3), or to receive HepB‐BD in addition to HepB3 (group U4). A supplemental cohort of HBV‐exposed infants (group E4) received HepB‐BD and HepB3. We compared the proportion of infants with protective antibodies against HBV (HBV surface antibody ≥ 10 mIU/mL) between groups U3 and U4 and groups U4 and E4 at 12 months of age. Between August 20 and October 9, 2019, we enrolled 281 mother/infant dyads; 88 (31.3%) returned at 12 months. Most infants had protective antibodies against HBV at 12 months: 92.9% (75.7%–98.2%) in group U3, 85.7% (67.5%–94.5%) in group U4 and 96.9% (95% CI: 81.2%–99.6%) in group E4. Trends held in estimates adjusted for loss‐to‐follow‐up (LTFU) and baseline imbalance across groups. In this first randomised trial assessing the addition of HepB‐BD to the hepatitis B vaccine schedule in SSA, we found that HBV‐unexposed infants who received the 3‐dose and 4‐dose vaccine series had similar immunogenicity against HBV at 12 months. A high proportion of infants, and notably HBV‐exposed infants, had protective antibodies. Though extrapolation of findings may be limited by LTFU, this study adds real‐world evidence regarding HepB‐BD implementation in sub‐Saharan Africa. Trial Registration: ClinicalTrials.gov identifier: NCT03897946 [ABSTRACT FROM AUTHOR]

COVID-19 disproportionately affected minorities, while research barriers to engage underserved communities persist. Serological studies reveal infection and vaccination histories within these communities, however lack of consensus on downstream evaluation methods impede meta-analyses and dampen the broader public health impact. To reveal the impact of COVID-19 and vaccine uptake among diverse communities and to develop rigorous serological downstream evaluation methods, we engaged racial and ethnic minorities in Massachusetts in a cross-sectional study (April—July 2022), screened blood and saliva for SARS-CoV-2 and human endemic coronavirus (hCoV) antibodies by bead-based multiplex assay and point-of-care (POC) test and developed across-plate normalization and classification boundary methods for optimal qualitative serological assessments. Among 290 participants, 91.4% reported receiving at least one dose of a COVID-19 vaccine, while 41.7% reported past SARS-CoV-2 infections, which was confirmed by POC- and multiplex-based saliva and blood IgG seroprevalences. We found significant differences in antigen-specific IgA and IgG antibody outcomes and indication of cross-reactivity with hCoV OC43. Finally, 26.5% of participants reported lingering COVID-19 symptoms, mostly middle-aged Latinas. Hence, prolonged COVID-19 symptoms were common among our underserved population and require public health attention, despite high COVID-19 vaccine uptake. Saliva served as a less-invasive sample-type for IgG-based serosurveys and hCoV cross-reactivity needed to be evaluated for reliable SARS-CoV-2 serosurvey results. The use of the developed rigorous downstream qualitative serological assessment methods will help standardize serosurvey outcomes and meta-analyses for future serosurveys beyond SARS-CoV-2. [ABSTRACT FROM AUTHOR]