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1.
Proc Natl Acad Sci U S A ; 120(2): e2211055120, 2023 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-36595676

RESUMO

Endemic Burkitt lymphoma (eBL) is a pediatric cancer coendemic with malaria in sub-Saharan Africa, suggesting an etiological link between them. However, previous cross-sectional studies of limited geographic areas have not found a convincing association. We used spatially detailed data from the Epidemiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) study to assess this relationship. EMBLEM is a case-control study of eBL from 2010 through 2016 in six regions of Kenya, Uganda, and Tanzania. To measure the intensity of exposure to the malaria parasite, Plasmodium falciparum, among children in these regions, we used high-resolution spatial data from the Malaria Atlas Project to estimate the annual number of P. falciparum infections from 2000 through 2016 for each of 49 districts within the study region. Cumulative P. falciparum exposure, calculated as the sum of annual infections by birth cohort, varied widely, with a median of 47 estimated infections per child by age 10, ranging from 4 to 315 infections. eBL incidence increased 39% for each 100 additional lifetime P. falciparum infections (95% CI: 6.10 to 81.04%) with the risk peaking among children aged 5 to 11 and declining thereafter. Alternative models using estimated annual P. falciparum infections 0 to 10 y before eBL onset were inconclusive, suggesting that eBL risk is a function of cumulative rather than recent cross-sectional exposure. Our findings provide population-level evidence that eBL is a phenotype related to heavy lifetime exposure to P. falciparum malaria and support emphasizing the link between malaria and eBL.


Assuntos
Linfoma de Burkitt , Malária Falciparum , Malária , Humanos , Linfoma de Burkitt/epidemiologia , Linfoma de Burkitt/genética , Plasmodium falciparum , Estudos de Casos e Controles , Uganda/epidemiologia , Quênia/epidemiologia , Tanzânia/epidemiologia , Estudos Transversais , Malária Falciparum/complicações , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Malária/epidemiologia
2.
Radiat Oncol ; 16(1): 95, 2021 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-34082782

RESUMO

BACKGROUND: We have carried out a study to determine the scope for reducing heart doses in photon beam radiotherapy of locally advanced non-small cell lung cancer (LA-NSCLC). MATERIALS AND METHODS: Baseline VMAT plans were created for 20 LA-NSCLC patients following the IDEAL-CRT isotoxic protocol, and were re-optimized after adding an objective limiting heart mean dose (MDHeart). Reductions in MDHeart achievable without breaching limits on target coverage or normal tissue irradiation were determined. The process was repeated for objectives limiting the heart volume receiving ≥ 50 Gy (VHeart-50-Gy) and left atrial wall volume receiving ≥ 63 Gy (VLAwall-63-Gy). RESULTS: Following re-optimization, mean MDHeart, VHeart-50-Gy and VLAwall-63-Gy values fell by 4.8 Gy and 2.2% and 2.4% absolute respectively. On the basis of associations observed between survival and cardiac irradiation in an independent dataset, the purposefully-achieved reduction in MDHeart is expected to lead to the largest improvement in overall survival. It also led to useful knock-on reductions in many measures of cardiac irradiation including VHeart-50-Gy and VLAwall-63-Gy, providing some insurance against survival being more strongly related to these measures than to MDHeart. The predicted hazard ratio (HR) for death corresponding to the purposefully-achieved mean reduction in MDHeart was 0.806, according to which a randomized trial would require 1140 patients to test improved survival with 0.05 significance and 80% power. In patients whose baseline MDHeart values exceeded the median value in a published series, the average MDHeart reduction was particularly large, 8.8 Gy. The corresponding predicted HR is potentially testable in trials recruiting 359 patients enriched for greater MDHeart values. CONCLUSIONS: Cardiac irradiation in RT of LA-NSCLC can be reduced substantially. Of the measures studied, reduction of MDHeart led to the greatest predicted increase in survival, and to useful knock-on reductions in other cardiac irradiation measures reported to be associated with survival. Potential improvements in survival can be trialled more efficiently in a population enriched for patients with greater baseline MDHeart levels, for whom larger reductions in heart doses can be achieved.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/radioterapia , Coração/efeitos da radiação , Neoplasias Pulmonares/radioterapia , Tratamentos com Preservação do Órgão , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Vasos Coronários/efeitos da radiação , Humanos , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Taxa de Sobrevida
3.
Br J Haematol ; 190(5): 772-782, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32395868

RESUMO

Platelet counts are decreased in Plasmodium falciparum malaria, which is aetiologically linked with endemic Burkitt lymphoma (eBL). However, the pattern of platelet counts in eBL cases is unknown. We studied platelet counts in 582 eBL cases and 2 248 controls enrolled in a case-control study in Uganda, Tanzania and Kenya (2010-2016). Mean platelet counts in controls or eBL cases with or without malaria-infection in controls versus eBLcases were compared using Student's t-test. Odds ratios (ORs) and two-sided 95% confidence intervals (95% CIs) were estimated using multiple logistic regression, controlling for age, sex, haemoglobin and white blood cell counts. Platelets were decreased with malaria infection in the controls [263 vs. 339 × 109 platelets/l, P < 0·0001; adjusted OR (aOR) = 3·42, 95% CI: 2·79-4·18] and eBL cases (314 vs. 367 × 109 platelets/l, P-value = 0·002; aOR = 2·36, 95% CI: 1·49-3·73). Unexpectedly, platelets were elevated in eBL cases versus  controls in overall analyses (mean: 353 vs. 307 × 109 platelets/l, P < 0·0001; aOR = 1·41; 95% CI: 1·12-1·77), and when restricted to malaria-positive (mean 314 vs. 263 × 109 platelets/l, P < 0·0001; OR = 2·26; 95% CI: 1·56-3·27) or malaria-negative (mean 367 vs. 339 × 109 platelets/l, P < 0·001; OR = 1·46; 95% CI: 1·17-1·83) subjects. Platelets were decreased with malaria infection in controls and eBL cases but elevated with eBL.


Assuntos
Linfoma de Burkitt/sangue , Malária/sangue , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Quênia , Masculino , Contagem de Plaquetas , Tanzânia , Uganda
4.
Br J Haematol ; 189(3): 489-499, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32072624

RESUMO

Endemic Burkitt lymphoma (eBL) is an aggressive childhood B-cell lymphoma associated with Plasmodium falciparum (Pf) malaria and Epstein-Barr virus (EBV) infections. Variation in the Human Leukocyte Antigen (HLA) system is suspected to play a role, but assessments using less accurate serology-based HLA typing techniques in small studies yielded conflicting results. We studied 200 eBL cases and 400 controls aged 0-15 years enrolled in northern Uganda and typed by accurate high-resolution HLA sequencing methods. HLA results were analyzed at one- or two-field resolution. Odds ratios and 95% confidence intervals (aOR, 95% CI) for eBL risk associated with common HLA alleles versus alleles that were rare (<1%) or differed by <2% between the cases and controls as the reference category, were estimated using multiple logistic regression adjusting for age, sex, microgeography, region, malaria positivity and treatment history, and genetic variants associated with eBL. Compared to the controls, eBL cases had a lower frequency of HLA-A*02 (aOR = 0·59, 95% CI 0·38-0·91), HLA-B*41 (aOR = 0·36, 95% CI 0·13-1·00), and HLA-B*58 alleles (aOR = 0·59, 95% CI 0·36-0·97). eBL cases had a lower frequency of HLA-DPB1 homozygosity (aOR = 0·57, 95% CI 0·40-0·82) but a higher frequency of HLA-DQA1 homozygosity (aOR = 2·19, 95% CI 1·42-3·37). Our results suggest that variation in HLA may be associated with eBL risk.


Assuntos
Linfoma de Burkitt/sangue , Antígenos HLA/metabolismo , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fatores de Risco , Uganda
5.
Int J Cancer ; 146(4): 953-969, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31054214

RESUMO

Endemic Burkitt lymphoma (eBL) is the most common childhood cancer in sub-Saharan African countries, however, few epidemiologic studies have been undertaken and none attempted enrolling cases from multiple countries. We therefore conducted a population-based case-control study of eBL in children aged 0-15 years old in six regions in Northern Uganda, Northern Tanzania and Western Kenya, enrolling 862 suspected cases and 2,934 population controls (response rates 98.5-100%), and processing ~40,000 vials of samples using standardized protocols. Risk factor questionnaires were administered, and malaria period prevalence was measured using rapid diagnostic tests (RDTs). A total of 80.9% of the recruited cases were diagnosed as eBL; 61.4% confirmed by histology. Associations with eBL risk were computed using logistic regression models adjusted for relevant confounders. Associations common in at least two countries were emphasized. eBL risk was decreased with higher maternal income and paternal education and elevated with history of inpatient malaria treatment >12 months before enrollment. Reporting malaria-attributed fever up to 6 months before enrollment and malaria-RDT positivity at enrollment were associated with decreased eBL risk. Conversely, reporting exposure to mass malaria suppression programs (e.g., indoor residual insecticide) was associated with elevated risk. HIV seropositivity was associated with elevated eBL risk, but the relative impact was small. The study shows that it is feasible to conduct networked, multisite population-based studies of eBL in Africa. eBL was inversely associated with socioeconomic status, positively associated with inpatient malaria treatment 12 months ago and with living in areas targeted for malaria suppression, which support a role of malaria in eBL.


Assuntos
Linfoma de Burkitt/epidemiologia , Doenças Endêmicas/estatística & dados numéricos , Soropositividade para HIV/epidemiologia , Malária/epidemiologia , Fatores Socioeconômicos , Adolescente , Linfoma de Burkitt/etiologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Soropositividade para HIV/complicações , Humanos , Lactente , Recém-Nascido , Quênia/epidemiologia , Malária/complicações , Malária/diagnóstico , Masculino , Prevalência , Fatores de Risco , Inquéritos e Questionários/estatística & dados numéricos , Tanzânia/epidemiologia , Uganda/epidemiologia
6.
Cancer Epidemiol Biomarkers Prev ; 29(1): 57-62, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31619404

RESUMO

BACKGROUND: The discovery of Epstein-Barr virus (EBV) in Burkitt lymphoma tumors represented the first link between a virus and cancer in humans, but the underlying role of this virus in endemic Burkitt lymphoma remains unclear. Nearly all children in Burkitt lymphoma-endemic areas are seropositive for EBV, but only a small percentage develop disease. Variation in EBV-directed immunity could be an explanatory cofactor. METHODS: We examined serum from 150 Burkitt lymphoma cases and 150 controls using a protein microarray that measured IgG and IgA antibodies against 202 sequences across the entire EBV proteome. Variation in the EBV-directed antibody repertoire between Burkitt lymphoma cases and controls was assessed using unpaired t tests. ORs quantifying the association between anti-EBV IgG response tertiles and Burkitt lymphoma status were adjusted for age, sex, and study year. RESULTS: Thirty-three anti-EBV IgG responses were elevated in Burkitt lymphoma cases compared with controls (P ≤ 0.0003). Burkitt lymphoma-associated IgG elevations were strongest for EBV proteins involved in viral replication and antiapoptotic signaling. Specifically, we observed ORs ≥4 for BMRF1 (early antigen), BBLF1 (tegument protein), BHRF1 (Bcl-2 homolog), BZLF1 (Zebra), BILF2 (glycoprotein), BLRF2 [viral capsid antigen (VCA)p23], BDLF4, and BFRF3 (VCAp18). Adjustment for malaria exposure and inheritance of the sickle cell variant did not alter associations. CONCLUSIONS: Our data suggest that the anti-EBV serologic profile in patients with Burkitt lymphoma is altered, with strong elevations in 33 of the measured anti-EBV IgG antibodies relative to disease-free children. IMPACT: The Burkitt lymphoma-specific signature included EBV-based markers relevant for viral replication and antiapoptotic activity, providing clues for future Burkitt lymphoma pathogenesis research.


Assuntos
Anticorpos Antivirais/sangue , Linfoma de Burkitt/epidemiologia , Doenças Endêmicas , Infecções por Vírus Epstein-Barr/epidemiologia , Herpesvirus Humano 4/isolamento & purificação , Adolescente , Anticorpos Antivirais/imunologia , Antígenos Virais/sangue , Antígenos Virais/imunologia , Apoptose/imunologia , Linfoma de Burkitt/sangue , Linfoma de Burkitt/virologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Infecções por Vírus Epstein-Barr/sangue , Infecções por Vírus Epstein-Barr/virologia , Feminino , Gana/epidemiologia , Herpesvirus Humano 4/imunologia , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Soroepidemiológicos , Proteínas Virais/sangue , Proteínas Virais/imunologia , Replicação Viral/imunologia
7.
PLoS Genet ; 15(3): e1008027, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30849090

RESUMO

Populations in sub-Saharan Africa have historically been exposed to intense selection from chronic infection with falciparum malaria. Interestingly, populations with the highest malaria intensity can be identified by the increased occurrence of endemic Burkitt Lymphoma (eBL), a pediatric cancer that affects populations with intense malaria exposure, in the so called "eBL belt" in sub-Saharan Africa. However, the effects of intense malaria exposure and sub-Saharan populations' genetic histories remain poorly explored. To determine if historical migrations and intense malaria exposure have shaped the genetic composition of the eBL belt populations, we genotyped ~4.3 million SNPs in 1,708 individuals from Ghana and Northern Uganda, located on opposite sides of eBL belt and with ≥ 7 months/year of intense malaria exposure and published evidence of high incidence of BL. Among 35 Ghanaian tribes, we showed a predominantly West-Central African ancestry and genomic footprints of gene flow from Gambian and East African populations. In Uganda, the North West population showed a predominantly Nilotic ancestry, and the North Central population was a mixture of Nilotic and Southern Bantu ancestry, while the Southwest Ugandan population showed a predominant Southern Bantu ancestry. Our results support the hypothesis of diverse ancestral origins of the Ugandan, Kenyan and Tanzanian Great Lakes African populations, reflecting a confluence of Nilotic, Cushitic and Bantu migrations in the last 3000 years. Natural selection analyses suggest, for the first time, a strong positive selection signal in the ATP2B4 gene (rs10900588) in Northern Ugandan populations. These findings provide important baseline genomic data to facilitate disease association studies, including of eBL, in eBL belt populations.


Assuntos
Linfoma de Burkitt/genética , Fluxo Gênico , Malária Falciparum/genética , Seleção Genética , Adolescente , África Subsaariana , Idoso , Linfoma de Burkitt/epidemiologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Doenças Endêmicas , Feminino , Genética Populacional , Estudo de Associação Genômica Ampla , Gana/epidemiologia , Migração Humana , Humanos , Incidência , Lactente , Recém-Nascido , Malária Falciparum/epidemiologia , Masculino , Pessoa de Meia-Idade , Modelos Genéticos , ATPases Transportadoras de Cálcio da Membrana Plasmática/genética , Polimorfismo de Nucleotídeo Único , Uganda/epidemiologia
8.
Am J Trop Med Hyg ; 100(1): 54-65, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30457091

RESUMO

The burden of Plasmodium falciparum (Pf) malaria in Kenya is decreasing; however, it is still one of the top 10 causes of morbidity, particularly in regions of western Kenya. Between April 2015 and June 2016, we enrolled 965 apparently healthy children aged 0-15 years in former Nyanza and Western Provinces in Kenya to characterize the demographic, geographic, and household risk factors of asymptomatic malaria as part of an epidemiologic study to investigate the risk factors for endemic Burkitt lymphoma. The children were sampled using a stratified, multistage cluster sampling survey design. Malaria was assessed by rapid diagnostic test (RDT) and thick-film microscopy (TFM). Primary analyses of Pf malaria prevalence (pfPR) are based on RDT. Associations between weighted pfPR and potential risk factors were evaluated using logistic regression, accounting for the survey design. Plasmodium falciparum malaria prevalence was 36.0% (27.5%, 44.5%) by RDT and 22.3% (16.0%, 28.6%) by TFM. Plasmodium falciparum malaria prevalence was positively associated with living in the lake-endemic area (adjusted odds ratio [aOR] 3.46; 95% confidence interval [95% CI] 1.63, 7.37), paternal occupation as peasant farmer (aOR 1.87; 1.08, 3.26) or manual laborer (aOR 1.83; 1.00, 3.37), and keeping dogs (aOR 1.62; 0.98-2.69) or cows (aOR 1.52; 0.96-2.40) inside or near the household. Plasmodium falciparum malaria prevalence was inversely associated with indoor residual insecticide spraying (IRS) (aOR 0.44; 0.19, 1.01), having a household connected to electricity (aOR 0.47; 0.22, 0.98), and a household with two (aOR 0.45; 0.22, 0.93) or ≥ three rooms (aOR 0.41; 0.18, 0.93). We report high but geographically heterogeneous pfPR in children in western Kenya and significant associations with IRS and household-level socioeconomic factors.


Assuntos
Infecções Assintomáticas/epidemiologia , Monitoramento Epidemiológico , Características da Família , Malária Falciparum/epidemiologia , Adolescente , Fatores Etários , Animais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Geografia , Humanos , Lactente , Recém-Nascido , Quênia/epidemiologia , Modelos Logísticos , Malária Falciparum/diagnóstico , Masculino , Razão de Chances , Plasmodium falciparum/isolamento & purificação , Prevalência , Fatores de Risco , Fatores Socioeconômicos , Inquéritos e Questionários
9.
Malar J ; 17(1): 240, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29925378

RESUMO

BACKGROUND: Plasmodium falciparum malaria is an important cause of morbidity in northern Uganda. This study was undertaken to assess village-, household-, and individual-level risk factors of asymptomatic falciparum malaria in children in 12 villages in northern Uganda. METHODS: Between 10/2011 and 02/2014, 1006 apparently healthy children under 16 years old were enrolled in 12 villages using a stratified, multi-stage, cluster survey design and assessed for P. falciparum malaria infection using the rapid diagnostic test (RDT) and thick film microscopy (TFM), and structured interviewer-administered questionnaires. Associations between weighted P. falciparum malaria prevalence (pfPR), based on RDT, and covariates were estimated as odds ratios and 95% confidence intervals (ORs, 95% CIs) using logistic models accounting for the survey design. RESULTS: Among 942 (93.5%) children successfully tested, pfPR was 52.4% by RDT and 32.7% by TFM. Overall pfPR was lower in villages where indoor residual insecticide spray (IRS) was, versus not, implemented (18.4% versus 75.2%, P < 0.0001). However, pfPR was heterogeneous both within IRS (10.6-34.8%) and non-IRS villages (63.6-86.2%). Elevated pfPR was associated with having a sibling who was RDT positive (OR 5.39, 95% CI 2.94-9.90, P = 0.0006) and reporting a fever at enrollment (aOR 4.80, 95% CI 1.94-11.9, P = 0.0094). Decreased pfPR was associated with living in an IRS village (adjusted OR 0.06, 95% CI 0.04-0.07, P < 0.0001), in a household with one (aOR 0.48, 95% CI 0.30-0.76) or more than one child below 5 years (aOR 0.23, 95% CI 0.12-0.44, Ptrend = 0.014), and reporting keeping a goat inside or near the house (aOR 0.42, 95% CI 0.29-0.62, P = 0.0021). CONCLUSIONS: The results show high but heterogeneous pfPR in villages in northern Uganda, confirm significantly decreased pfPR associated with IRS implementation, and suggest significant associations with some household characteristics. Further research is needed to elucidate the factors influencing malaria heterogeneity in villages in Uganda.


Assuntos
Infecções Assintomáticas/epidemiologia , Malária Falciparum/epidemiologia , Plasmodium falciparum/isolamento & purificação , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Testes Diagnósticos de Rotina , Características da Família , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Microscopia , Prevalência , Fatores de Risco , População Rural , Uganda/epidemiologia
10.
Cancers (Basel) ; 10(6)2018 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-29865259

RESUMO

Epstein-Barr virus (EBV) is linked to several cancers, including endemic Burkitt lymphoma (eBL), but causal variants are unknown. We recently reported novel sequence variants in the LMP-1 gene and promoter in EBV genomes sequenced from 13 of 14 BL biopsies. Alignments of the novel sequence variants for 114 published EBV genomes, including 27 from BL cases, revealed four LMP-1 variant patterns, designated A to D. Pattern A variant was found in 48% of BL EBV genomes. Here, we used PCR-Sanger sequencing to evaluate 50 additional BL biopsies from Ghana, Brazil, and Argentina, and peripheral blood samples from 113 eBL cases and 115 controls in Uganda. Pattern A was found in 60.9% of 64 BL biopsies evaluated. Compared to PCR-negative subjects in Uganda, detection of Pattern A in peripheral blood was associated with eBL case status (odds ratio [OR] 31.7, 95% confidence interval: 6.8⁻149), controlling for relevant confounders. Variant Pattern A and Pattern D were associated with eBL case status, but with lower ORs (9.7 and 13.6, respectively). Our results support the hypothesis that EBV LMP-1 Pattern A may be associated with eBL, but it is not the sole associated variant. Further research is needed to replicate and elucidate our findings.

11.
EBioMedicine ; 25: 58-65, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29033373

RESUMO

BACKGROUND: Plasmodium falciparum (Pf) malaria infection is suspected to cause endemic Burkitt Lymphoma (eBL), but the evidence remains unsettled. An inverse relationship between sickle cell trait (SCT) and eBL, which supports that between malaria and eBL, has been reported before, but in small studies with low power. We investigated this hypothesis in children in a population-based study in northern Uganda using Mendelian Randomization. METHODS: Malaria-related polymorphisms (SCT, IL10, IL1A, CD36, SEMA3C, and IFNAR1) were genotyped in 202 eBL cases and 624 controls enrolled during 2010-2015. We modeled associations between genotypes and eBL or malaria using logistic regression. FINDINGS: SCT was associated with decreased risk of eBL (adjusted odds ratio [OR] 0·37, 95% CI 0·21-0·66; p=0·0003). Decreased risk of eBL was associated with IL10 rs1800896-CT (OR 0·73, 95% CI 0·50-1·07) and -CC genotypes (OR 0·53, 95% CI 0·29-0·95, ptrend=0·019); IL1A rs2856838-AG (OR 0·56, 95% CI 0·39-0·81) and -AA genotype (OR 0·50, 95% CI 0·28-1·01, ptrend=0·0016); and SEMA3C rs4461841-CT or -CC genotypes (OR 0·57, 95% CI 0·35-0·93, p=0·0193). SCT and IL10 rs1800896, IL1A rs2856838, but not SEMA3C rs4461841, polymorphisms were associated with decreased risk of malaria in the controls. INTERPRETATION: Our results support a causal effect of malaria infection on eBL.


Assuntos
Linfoma de Burkitt/genética , Predisposição Genética para Doença , Malária Falciparum/genética , Análise da Randomização Mendeliana , Adolescente , Linfoma de Burkitt/complicações , Linfoma de Burkitt/epidemiologia , Linfoma de Burkitt/parasitologia , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Lactente , Recém-Nascido , Malária Falciparum/complicações , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Plasmodium falciparum/patogenicidade , Uganda/epidemiologia
12.
Malar J ; 16(1): 124, 2017 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-28320389

RESUMO

BACKGROUND: Falciparum malaria is an important risk factor for African Burkitt lymphoma (BL), but few studies have evaluated malaria patterns in healthy BL-age children in populations where both diseases are endemic. To obtain accurate current data, patterns of asymptomatic malaria were investigated in northern Uganda, where BL is endemic. METHODS: Between 2011 and 2015, 1150 apparently healthy children under 15 years old were sampled from 100 villages in northern Uganda using a stratified, multi-stage, cluster survey design. Falciparum malaria prevalence (pfPR) was assessed by questionnaire, rapid diagnostic test (RDT) and thick film microscopy (TFM). Weighted pfPR and unadjusted and adjusted associations of prevalence with covariates were calculated using logistic models and survey methods. RESULTS: Based on 1143 children successfully tested, weighted pfPR was 54.8% by RDT and 43.4% by TFM. RDT sensitivity and specificity were 97.5 and 77.8%, respectively, as compared to TFM, because RDT detect malaria antigens, which persist in peripheral blood after clinical malaria, thus results based on RDT are reported. Weighted pfPR increased from 40% in children aged under 2 years to 61.8% in children aged 6-8 years (odds ratio 2.42, 95% confidence interval (CI) 1.26-4.65), then fell slightly to 49% in those aged 12-15 years. Geometric mean parasite density was 1805.5 parasites/µL (95% CI 1344.6-2424.3) among TFM-positive participants, and it was higher in children aged <5 years at 5092.9/µL (95% CI 2892.7-8966.8) and lower in those aged ≥10 years at 983.8/µL (95% CI 472.7-2047.4; P = 0.001). Weighted pfPR was lower in children residing in sub-regions employing indoor residual spraying (IRS) than in those residing in non-IRS sub-regions (32.8 versus 65.7%; OR 0.26, 95% CI 0.14, 0.46). However, pfPR varied both within IRS (3.2-55.3%) and non-IRS sub-regions (29.8-75.8%; Pheterogeneity <0.001). pfPR was inversely correlated with a child's mother's income (P = 0.011) and positively correlated with being enrolled in the wet season (P = 0.076), but sex was irrelevant. CONCLUSIONS: The study observed high but geographically and demographically heterogenous patterns of asymptomatic malaria prevalence among children living in northern Uganda. These results provide important baseline data that will enable precise evaluation of associations between malaria and BL.


Assuntos
Linfoma de Burkitt/epidemiologia , Doenças Endêmicas , Malária Falciparum/epidemiologia , Adolescente , Criança , Pré-Escolar , Testes Diagnósticos de Rotina , Feminino , Humanos , Lactente , Recém-Nascido , Malária Falciparum/parasitologia , Masculino , Plasmodium falciparum/isolamento & purificação , Prevalência , Sensibilidade e Especificidade , Uganda/epidemiologia
14.
Blood Adv ; 1(9): 535-544, 2017 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-29296973

RESUMO

Burkitt lymphoma (BL), the most common pediatric cancer in sub-Saharan Africa, is a malignancy of antigen-experienced B lymphocytes. High-throughput sequencing (HTS) of the immunoglobulin heavy (IGH) and light chain (IGK/IGL) loci was performed on genomic DNA from 51 primary BL tumors: 19 from Uganda and 32 from Ghana. Reverse transcription polymerase chain reaction analysis and tumor RNA sequencing (RNAseq) was performed on the Ugandan tumors to confirm and extend the findings from the HTS of tumor DNA. Clonal IGH and IGK/IGL rearrangements were identified in 41 and 46 tumors, respectively. Evidence for rearrangement of the second IGH allele was observed in only 6 of 41 tumor samples with a clonal IGH rearrangement, suggesting that the normal process of biallelic IGHD to IGHJ diversity-joining (DJ) rearrangement is often disrupted in BL progenitor cells. Most tumors, including those with a sole dominant, nonexpressed DJ rearrangement, contained many IGH and IGK/IGL sequences that differed from the dominant rearrangement by < 10 nucleotides, suggesting that the target of ongoing mutagenesis of these loci in BL tumor cells is not limited to expressed alleles. IGHV usage in both BL tumor cohorts revealed enrichment for IGHV genes that are infrequently used in memory B cells from healthy subjects. Analysis of publicly available DNA sequencing and RNAseq data revealed that these same IGHV genes were overrepresented in dominant tumor-associated IGH rearrangements in several independent BL tumor cohorts. These data suggest that BL derives from an abnormal B-cell progenitor and that aberrant mutational processes are active on the immunoglobulin loci in BL cells.

15.
Int J Cancer ; 140(7): 1597-1608, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-27997697

RESUMO

Burkitt lymphoma (BL) is a malignant disease, which is frequently found in areas with holoendemic Plasmodium falciparum malaria. We have previously found that the VAR2CSA protein is present on malaria-infected erythrocytes and facilitates a highly specific binding to the placenta. ofCS is absent in other non-malignant tissues and thus VAR2CSA generally facilitates parasite sequestration and accumulation in pregnant women. In this study, we show that the specific receptor for VAR2CSA, the oncofetal chondroitin sulfate (ofCS), is likewise present in BL tissue and cell lines. We therefore explored whether ofCS in BL could act as anchor site for VAR2CSA-expressing infected erythrocytes. In contrast to the placenta, we found no evidence of in vivo sequestering of infected erythrocytes in the BL tissue. Furthermore, we found VAR2CSA-specific antibody titers in children with endemic BL to be lower than in control children from the same malaria endemic region. The abundant presence of ofCS in BL tissue and the absence of ofCS in non-malignant tissue encouraged us to examine whether recombinant VAR2CSA could be used to target BL. We confirmed the binding of VAR2CSA to BL-derived cells and showed that a VAR2CSA drug conjugate efficiently killed the BL-derived cell lines in vitro. These results identify ofCS as a novel therapeutic BL target and highlight how VAR2CSA could be used as a tool for the discovery of novel approaches for directing BL therapy.


Assuntos
Antígenos de Neoplasias/metabolismo , Linfoma de Burkitt/metabolismo , Sulfatos de Condroitina/metabolismo , Malária Falciparum/metabolismo , Placenta/metabolismo , Placenta/parasitologia , Adolescente , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/imunologia , Linfoma de Burkitt/parasitologia , Linhagem Celular Tumoral , Criança , Pré-Escolar , Eritrócitos/parasitologia , Feminino , Humanos , Imunoglobulina G/metabolismo , Malária Falciparum/complicações , Masculino , Plasmodium falciparum/imunologia , Gravidez , Proteoglicanas/metabolismo , Proteínas Recombinantes/metabolismo
16.
Trends Cancer ; 2(8): 416-428, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27891533

RESUMO

Survival with human immunodeficiency virus (HIV) infection has greatly improved due to effective antiretroviral therapy (ART). As infectious complications have declined, malignancy now accounts for over one-third of deaths among people living with HIV (PLWH). Based on practices in the general population, cancer screening of PLWH can decrease both morbidity and mortality. In this article, we review and consider directed approaches for colorectal, breast, cervical and lung cancer screening. Furthermore, routine physical examinations may detect lymphomas and skin, anal and oral cancers. Comprehensive cancer prevention in PLWH should also include ART adherence, vaccination against oncogenic viruses, treatment of hepatitis viruses and smoking cessation. Cancer screening for PLWH warrants further research on safety and efficacy as well as targeted efforts to increase adherence.


Assuntos
Detecção Precoce de Câncer , Infecções por HIV/complicações , Neoplasias/diagnóstico , Humanos , Neoplasias/etiologia
17.
Photochem Photobiol ; 92(5): 735-41, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27400420

RESUMO

International patterns suggest germ cell testicular cancer (GCTC) incidence may be lower in lower latitudes. To investigate this possibility, we examined GCTC incidence by latitude (population centroid in 2000) for men ≥15 years within two reasonably homogeneous countries, the United States and Australia. In the United States, we examined age-adjusted incidence/latitude trends using data from states (2001-2010) and local-area registries (1980-2011). In Australia, we evaluated incidence/latitude trends in 61 Statistical Divisions (2000-2009). In U.S. White men (68 566 cases), state incidences increased by latitude, rising 5.74% (4.45-7.05%) per 5°North latitude increment. Similar trends were found for seminoma and nonseminoma subtypes (P < 0.001). In U.S. Black men (2256 cases), the association was also seen (4.9%; 0.2-9.7%). In local U.S. data, similar increases in incidence with latitude were present in each of the last three decades. In Australia (6042 cases), the incidence increased by 4.43% (95% CI: 1.54-7.39%) per 5°South, and trends for subtypes were similar. Thus, we found that incidence of GCTC in both White and Black men increased significantly with distance from the equator, approximately 1% per degree within the range of latitudes studied.


Assuntos
Neoplasias Embrionárias de Células Germinativas/epidemiologia , Luz Solar , Neoplasias Testiculares/epidemiologia , Adulto , Austrália/epidemiologia , Humanos , Masculino , Neoplasias Embrionárias de Células Germinativas/etnologia , Fatores de Risco , Neoplasias Testiculares/etnologia , Estados Unidos/epidemiologia , População Branca
18.
Cancer Causes Control ; 27(8): 955-64, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27306518

RESUMO

PURPOSE: To evaluate changes in cancer mortality burden over time by assessing temporal trends in life expectation for Australian residents diagnosed with cancer. METHODS: The study cohort consisted of all people diagnosed with cancer in the period 1990-2000 and aged 15-89 years (n = 1,275,978), with mortality follow-up to 31 December 2010. Flexible parametric survival models incorporating background age-sex-year-specific population mortality rates were applied to generate the observed survival curves for all cancers combined and selected major cancer types. Predicted values of loss of life expectancy (LOLE) in years were generated and then averaged across calendar year and age group (15-49, 50-69 and 70-89 years) or spread of disease (localized, regional, distant, unknown). RESULTS: The greatest LOLE burden was for lung cancer (14.3 years per diagnosis) and lowest for melanoma (2.5 years). There was a significant decrease in LOLE over time (-0.13 LOLE per year) for all cancers combined. Decreases were also observed for female breast cancer (-0.21), prostate cancer (-0.17), colorectal cancer (-0.08), melanoma (-0.07) and stomach cancer (-0.02), with slight increases for lung cancer (+0.04). When restricted to the sub-cohort from New South Wales with spread of disease information, these decreases in LOLE were primarily among cancers categorized as localized or regional spread at diagnosis. CONCLUSIONS: In Australia, persons diagnosed with cancer have a steadily improving outlook that exceeds that expected by general improvement in population life expectancy. The overall improvement is observed in persons with localized or regional cancers but not in those with advanced cancers, findings which encourage earlier diagnosis.


Assuntos
Expectativa de Vida , Neoplasias/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Neoplasias/mortalidade , Adulto Jovem
19.
Sci Rep ; 5: 16706, 2015 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-26593963

RESUMO

Epstein Barr virus (EBV) sequence variation is thought to contribute to Burkitt lymphoma (BL), but lack of data from primary BL tumors hampers efforts to test this hypothesis. We directly sequenced EBV from 12 BL biopsies from Ghana, Brazil, and Argentina, aligned the obtained reads to the wild-type (WT) EBV reference sequence, and compared them with 100 published EBV genomes from normal and diseased people from around the world. The 12 BL EBVs were Type 1. Eleven clustered close to each other and to EBV from Raji BL cell line, but away from 12 EBVs reported from other BL-derived cell lines and away from EBV from NPC and healthy people from Asia. We discovered 23 shared novel nucleotide-base changes in the latent membrane protein (LMP)-1 promoter and gene (associated with 9 novel amino acid changes in the LMP-1 protein) of the 11 BL EBVs. Alignment of this region for the 112 EBV genomes revealed four distinct patterns, tentatively termed patterns A to D. The distribution of BL EBVs was 48%, 8%, 24% and 20% for patterns A to D, respectively; the NPC EBV's were Pattern B, and EBV-WT was pattern D. Further work is needed to investigate the association between EBV LMP-1 patterns with BL.


Assuntos
Linfoma de Burkitt/virologia , Infecções por Vírus Epstein-Barr/virologia , Regulação Viral da Expressão Gênica , Genoma Viral , Herpesvirus Humano 4/genética , Proteínas da Matriz Viral/genética , África , Sequência de Aminoácidos , Biópsia , Linfoma de Burkitt/etiologia , Linfoma de Burkitt/patologia , Criança , Pré-Escolar , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/patologia , Feminino , Variação Genética , Genótipo , Herpesvirus Humano 4/patogenicidade , Humanos , Masculino , Dados de Sequência Molecular , Filogenia , Regiões Promotoras Genéticas , Alinhamento de Sequência , Análise de Sequência de DNA , América do Sul
20.
BMJ Open ; 5(4): e006740, 2015 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-25869684

RESUMO

OBJECTIVES: Communication of relevant prognostic information is critical in helping patients understand the implications of their cancer diagnosis. We describe measures of prognosis to help communicate relevant prognostic information to improve patients' understanding of the implications of their cancer diagnosis. SETTING: Australia-wide population-based cancer registry cohort. PARTICIPANTS: 870,878 patients aged 15-89 years diagnosed with invasive cancer between 1990 and 2007, with mortality follow-up information to December 2010. PRIMARY AND SECONDARY OUTCOME MEASURES: Flexible parametric models were used to estimate loss of life expectancy (LOLE), remaining life expectancy (RLE) and 10-year cumulative probability of cancer-specific death (1-relative survival). RESULTS: On average, Australians diagnosed with cancer at age 40 years faced losing an average of 11.2 years of life (95% CI 11.1 to 11.4) due to their cancer, while those diagnosed at 80 years faced losing less, an average of 3.9 years (3.9 to 4.0) because of higher competing mortality risks. In contrast, younger people had lower estimated cumulative probabilities of cancer-specific death within 10 years (40 years: 21.5%, 21.4% to 22.1%) compared with older people (80 years: 55.4%, 55.0% to 55.9%). The patterns for individual cancers varied widely, both by cancer type and by age within cancer type. CONCLUSIONS: The LOLE and RLE measures provide complementary messages to standard relative survival estimates (expressed here in terms of cumulative probability of cancer-specific death). Importantly, relative survival per se underplays the greater absolute impact that a cancer diagnosis has at a younger age on LOLE. When presented in isolation for all cancers, it may provide a misleading impression of future mortality burden of cancer overall, and furthermore, it will obscure patterns of mortality by type and by age data within type. Alternative measures of LOLE, therefore, provide important communication about mortality risk to patients with cancer worldwide and should be incorporated into standard reporting and dissemination strategies.


Assuntos
Expectativa de Vida , Neoplasias/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Neoplasias/mortalidade , Prognóstico , Fatores de Risco , Análise de Sobrevida , Adulto Jovem
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