Burkitt's lymphoma in Africa, a review of the epidemiology and etiology

A Dental Extraction Revealing a Multisystem Burkitt's Lymphoma: A Case Report

Burkitt's lymphoma is rare but highly aggressive and very fast-growing B-cell non-Hodgkin's lymphoma (NHL). It can affect any organ such as the central nervous system, jaw, intestines, kidneys, ovaries, and other organs. It results from the malignant evolution and proliferation of B-type lymphoid cells. The diagnosis is based on a biopsy of a tumor mass or bone marrow aspiration revealing the presence of tumor cells. We report the case of a 7 year old child who was referred for a gingival swelling evolving since 1 month following a dental extraction. Imaging and anatomopathological examination after biopsy concludes to a multi systemic Burkitt's lymphoma. A chemotherapy was immediately started with spectacular complete remission.

A rare case of Burkitt's lymphoma of the breast in a 19-year-old male: Case report

Key Clinical Message

Burkitt's lymphoma is a highly aggressive non-Hodgkin's lymphoma that can affect various parts of the body, which include jaw, facial bones, retroperitoneum, and abdominal viscera, it is worth noting that breast involvement is extremely rare in Burkitt's lymphoma and has not been documented.

Abstract

Burkitt's lymphoma is a highly aggressive non-Hodgkin's lymphoma that can affect various parts of the body including breast. This sarcoma is identified as a rapidly fatal malignant lymphoma syndrome and 50% of all malignant tumors in children. However, breast involvement has not been documented. A 19-year-old male presented to our emergency department with a left breast swelling for 2 months associated with drenching night sweats, weight loss and evening fevers. Physical examination revealed a mass measuring approximately 15 × 16 × 15 cm in the widest dimension, skin hyperpigmentation, no nipple discolorations, discharges, and non-tender on palpation. Biopsy was done, and the histology report revealed sheets of monomorphic medium lymphocytes with a high mitotic rate and frequent apoptotic bodies showing a starry-sky appearance. The immunohistochemistry report revealed positive staining for Ki-67, CD-20, and CD-10 tumor markers and CD45 on flow cytometry. The patient was started on aggressive hydration, rasubricase administration, CODOX-M/IVAC regimen 6 cycles, and G-CSF and registered significant reduction in the size of the mass. Burkitt's lymphoma is a highly aggressive non-Hodgkin's lymphoma that can affect various parts of the body. It commonly involves the jaw, facial bones, retroperitoneum, and abdominal viscera. The disease typically affects young patients in areas of high incidence, such as the jaw, whereas visceral involvement is more common in older patients in low-incidence areas. It is worth noting that breast involvement is extremely rare in Burkitt's lymphoma.

Epigenetic Alteration of the Cancer-Related Gene TGFBI in B Cells Infected with Epstein-Barr Virus and Exposed to Aflatoxin B1: Potential Role in Burkitt Lymphoma Development

Burkitt lymphoma (BL) is a malignant B cell neoplasm that accounts for almost half of pediatric cancers in sub-Saharan African countries. Although the BL endemic prevalence is attributable to the combination of Epstein-Barr virus (EBV) infection with malaria and environmental carcinogens exposure, such as the food contaminant aflatoxin B1 (AFB1), the molecular determinants underlying the pathogenesis are not fully understood. Consistent with the role of epigenetic mechanisms at the interface between the genome and environment, AFB1 and EBV impact the methylome of respectively leukocytes and B cells specifically. Here, we conducted a thorough investigation of common epigenomic changes following EBV or AFB1 exposure in B cells. Genome-wide DNA methylation profiling identified an EBV-AFB1 common signature within the TGFBI locus, which encodes for a putative tumor suppressor often altered in cancer. Subsequent mechanistic analyses confirmed a DNA-methylation-dependent transcriptional silencing of TGFBI involving the recruitment of DNMT1 methyltransferase that is associated with an activation of the NF-κB pathway. Our results reveal a potential common mechanism of B cell transformation shared by the main risk factors of endemic BL (EBV and AFB1), suggesting a key determinant of disease that could allow the development of more efficient targeted therapeutic strategies.

The Role of Epstein-Barr Virus in Modulating Key Tumor Suppressor Genes in Associated Malignancies: Epigenetics, Transcriptional, and Post-Translational Modifications

Epstein-Barr virus (EBV) is ubiquitous and carried by approximately 90% of the world’s adult population. Several mechanisms and pathways have been proposed as to how EBV facilitates the pathogenesis and progression of malignancies, such as Hodgkin’s lymphoma, Burkitt’s lymphoma, nasopharyngeal carcinoma, and gastric cancers, the majority of which have been linked to viral proteins that are expressed upon infection including latent membrane proteins (LMPs) and Epstein-Barr virus nuclear antigens (EBNAs). EBV expresses microRNAs that facilitate the progression of some cancers. Mostly, EBV induces epigenetic silencing of tumor suppressor genes, degradation of tumor suppressor mRNA transcripts, post-translational modification, and inactivation of tumor suppressor proteins. This review summarizes the mechanisms by which EBV modulates different tumor suppressors at the molecular and cellular levels in associated cancers. Briefly, EBV gene products upregulate DNA methylases to induce epigenetic silencing of tumor suppressor genes via hypermethylation. MicroRNAs expressed by EBV are also involved in the direct targeting of tumor suppressor genes for degradation, and other EBV gene products directly bind to tumor suppressor proteins to inactivate them. All these processes result in downregulation and impaired function of tumor suppressors, ultimately promoting malignances.

A novel prognostic index for sporadic Burkitt lymphoma in adult patients: a real-word multicenter study

Background

Adult sporadic Burkitt lymphoma (BL) is a rare but highly aggressive subtype of lymphoma which lacks its own unique prognostic model. Systemic inflammatory biomarkers have been confirmed as prognostic markers in several types of malignancy. Our objective was to explore the predictive value of pretreatment inflammatory biomarkers and establish a novel, clinically applicable prognostic index for adult patients with sporadic BL.

Methods

We surveyed retrospectively 336 adult patients with newly diagnosed sporadic BL at 8 Chinese medical centers and divided into training cohort (n = 229) and validation cohort (n = 107). The pretreatment inflammatory biomarkers were calculated for optimal cut-off value. The association between serum biomarkers and overall survival (OS) was analyzed by Kaplan–Meier curves and Cox proportional models. The risk stratification was defined based on normal LDH level, Ann Arbor stage of I and completely resected abdominal lesion or single extra-abdominal mass < 10 cm.

Results and conclusions

Univariate and multivariate analyses revealed that platelets< 254 × 10⁹/L, albumin< 40 g/L, lactate dehydrogenase≥334 U/L independently predicted unfavorable OS. We used these data as the basis for the prognostic index, in which patients were stratified into Group 1 (no or one risk factor), Group 2 (two risk factors), or Group 3 (three risk factors), which were associated with 5-year OS rates of 88.1, 72.4, and 45%, respectively. In the subgroup analysis for high-risk patients, our prognostic model results showed that high-risk patients with no more than one adverse factor presented a 5-year survival rate of 85.9%, but patients with three adverse factors had a 5-year survival rate of 43.0%. Harrell’s concordance index (C-index) of the risk group score was 0.768. Therefore, the new prognostic model could be used to develop risk-adapted treatment approaches for adult sporadic BL.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09144-1.

CD4 + T cells are found within endemic Burkitt lymphoma and modulate Burkitt lymphoma precursor cell viability and expression of pathogenically relevant Epstein-Barr virus genes

Endemic Burkitt lymphoma (eBL) is an aggressive B cell cancer characterized by an IgH/c-myc translocation and the harboring of Epstein-Barr virus (EBV). Evidence accumulates that CD4 + T cells might contribute to eBL pathogenesis. Here, we investigate the presence of CD4 + T cells in primary eBL tissue and their potential dichotomous impact on an EBV-infected pre-eBL cell model using ex vivo material and in vitro co-cultures. In addition, we establish a novel method to study the effect of IgH/c-myc translocation in primary B cells by employing a CRISPR/Cas9 knock-in approach to introduce and tag de novo translocation. We unprecedently document that CD4 + T cells are present in primary eBL tumor tissue. Furthermore, we demonstrate that CD4 + T cells on the one hand suppress eBL development by killing pre-eBL cells lacking IgH/c-myc translocation in vitro and on the other hand indirectly promote eBL development by inducing crucial EBV Latency III to Latency I switching in pre-eBL cells. Finally, we show that while the mere presence of an IgH/c-myc translocation does not suffice to escape CD4 + T-cell-mediated killing in vitro, the CD4 + T-cell-mediated suppression of EBV's Latency III program in vivo may allow cells harboring an IgH/c-myc translocation and additional mutations to evade immune control and proliferate by means of deregulated c-myc activity, resulting in neoplasia. Thus, our study highlights the dichotomous effects of CD4 + T cells and the mechanisms involved in eBL pathogenesis, suggests mechanisms of their impact on eBL progression, and provides a novel in vitro model for further investigation of IgH/c-myc translocation.

Breast Cancer Clinical Trials: The Landscape at the Uganda Cancer Institute and Lessons Learned

The Uganda Cancer Institute, the sole national comprehensive cancer center in Uganda, has a long and rich history of clinical investigation and locally relevant cancer research. Given the increasing burden of breast cancer in Uganda and elsewhere in sub-Saharan Africa (SSA) and driven by the limited availability of immunohistochemistry (IHC), we launched a clinical trial aimed at evaluating locally available diagnostics to detect the presence of hormone receptors (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor 2. Preliminary data from 32 women in the diagnostic component of the study reveal high sensitivity and specificity for estrogen receptor and progesterone receptor and high specificity for human epidermal growth factor receptor 2 when comparing reverse transcriptase polymerase chain reaction with the gold standard (IHC). Innovative diagnostic and treatment strategies are required to address the burden of breast cancer that is increasing throughout SSA. Given the costs, infrastructure, and trained personnel associated with IHC, alternative testing options (including reverse transcriptase polymerase chain reaction as tested in our study) may provide an expedited and cost-effective method to determine receptor testing in breast cancer. Clinical trials conducted in the local setting are critical to determining optimal strategies for effective breast cancer management in SSA.

Molecular Update and Evolving Classification of Large B-Cell Lymphoma

Diffuse large B-cell lymphomas (DLBCLs) are aggressive B-cell neoplasms with considerable clinical, biologic, and pathologic diversity. The application of high throughput technologies to the study of lymphomas has yielded abundant molecular data leading to the identification of distinct molecular identities and novel pathogenetic pathways. In light of this new information, newly refined diagnostic criteria have been established in the fourth edition of the World Health Organization (WHO) consensus classification of lymphomas, which was revised in 2016. This article reviews the histopathological and molecular features of the various aggressive B-cell lymphoma subtypes included in the updated classification.

Association of killer cell immunoglobulin-like receptors with endemic Burkitt lymphoma in Kenyan children

Endemic Burkitt lymphoma (eBL) is an aggressive pediatric B cell lymphoma, common in Equatorial Africa. Co-infections with Epstein-Barr virus (EBV) and Plasmodium falciparum, coupled with c-myc translocation are involved in eBL etiology. Infection-induced immune evasion mechanisms to avoid T cell cytotoxicity may increase the role of Natural killer (NK) cells in anti-tumor immunosurveillance. Killer immunoglobulin-like receptor (KIR) genes on NK cells exhibit genotypic and allelic variations and are associated with susceptibility to diseases and malignancies. However, their role in eBL pathogenesis remains undefined. This retrospective study genotyped sixteen KIR genes and compared their frequencies in eBL patients (n = 104) and healthy geographically-matched children (n = 104) using sequence-specific primers polymerase chain reaction (SSP-PCR) technique. The relationship between KIR polymorphisms with EBV loads and eBL pathogenesis was investigated. Possession of ≥ 4 activating KIRs predisposed individuals to eBL (OR = 3.340; 95% CI 1.530-7.825; p = 0.004). High EBV levels were observed in Bx haplogroup (p = 0.016) and AB genotypes (p = 0.042) relative to AA haplogroup and AA genotype respectively, in eBL patients but not in healthy controls. Our results suggest that KIR-mediated NK cell stimulation could mute EBV control, contributing to eBL pathogenesis.

Triclosan induces apoptosis in Burkitt lymphoma-derived BJAB cells through caspase and JNK/MAPK pathways

Burkitt's lymphoma (BL) is the fastest growing human tumor. Current treatment consists of a multiagent regimen of cytotoxic drugs with serious side effjects including tumor lysis, cardiotoxicity, hepatic impairment, neuropathy, myelosuppression, increased susceptibility to malignancy, and death. Furthermore, therapeutic interventions in areas of BL prevalence are not as feasible as in high-income countries. Therefore, there exists an urgent need to identify new therapies with a safer profile and improved accessibility. Triclosan (TCS), an antimicrobial used in personal care products and surgical scrubs, has gained considerable interest as an antitumor agent due to its interference with fatty acid synthesis. Here, we investigate the antitumor properties and associated molecular mechanisms of TCS in BL-derived BJAB cells. Dose-dependent cell death was observed following treatment with 10-100 µM TCS for 24 h, which was associated with membrane phospholipid scrambling, compromised permeability, and cell shrinkage. TCS-induced cell death was accompanied by elevated intracellular calcium, perturbed redox balance, chromatin condensation, and DNA fragmentation. TCS upregulated Bad expression and downregulated that of Bcl2. Moreover, caspase and JNK MAPK signaling were required for the full apoptotic activity of TCS. In conclusion, this report identifies TCS as an antitumor agent and provides new insights into the molecular mechanisms governing TCS-induced apoptosis in BL cells.

Activation-induced cytidine deaminase: in sickness and in health

Activation Induced cytidine Deaminase (AID) is an essential enzyme of the adaptive immune system. Its canonical activity is restricted to B lymphocytes, playing an essential role in the diversification of antibodies by enhancing specificity and changing affinity. This is possible through its DNA deaminase function, leading to mutations in DNA. In the last decade, AID has been assigned an additional function: that of a powerful DNA demethylator. Adverse cellular conditions such as chronic inflammation can lead to its deregulation and overexpression. It is an important driver of B-cell lymphoma due to its natural ability to modify DNA through deamination, leading to mutations and epigenetic changes. However, the deregulation of AID is not restricted to lymphoid cells. Recent findings have provided new insights into the role that this protein plays in the development of non-lymphoid cancers, with some research shedding light on novel AID-driven mechanisms of cellular transformation. In this review, we provide an updated narrative of the normal physiological functions of AID. Additionally, we review and discuss the recent research studies that have implicated AID in carcinogenesis in varying tissue types including lymphoid and non-lymphoid cancers. We review the mechanisms, whereby AID promotes carcinogenesis and highlight important areas of future research.

Paediatric jaw tumours: experiences and findings from a resource limited tertiary health care center

Introduction

primary maxillofacial tumors are uncommon in pediatric patients. When they do occur, the tissue damage caused directly alters facial growth, development as well as psycho-social evolution. This study was carried out to determine the pattern, sociodemographic characteristics and histologic peculiarities of paediatric jaw tumors in our environment.

Methods

a retrospective hospital-based study where the case notes of children below the age of 14 years who presented with jaw tumors and tumor-like lesions from January 2014 to December 2018 were studied.

Results

eighty-two patients were studied; patients aged 10-14 years had the highest representation. Mean time of presentation was 8 months with jaw swelling being the commonest presentation (84.1%). Majority of the fathers were in their 4^th decade of life while most of the mothers were in their third decade of life and both parents possessed primary school certificate as their highest level of educational attainment. Fathers were mostly traders, while mothers were mostly full-time housewives. The maxilla and mandible were most commonly affected with the left side showing higher preponderance. Burkitt lymphoma (19 (23.2%)) and adenomatoid odontogenic tumor (14 (17.1%)) were the commonest lesions. When the tumor involved both the maxilla and the mandible, the tumor was most likely malignant.

Conclusion

in our center, paediatric jaw tumors are commonest in male children with the 10-14 years´ age group most commonly affected. Burkitt lymphoma and adenomatoid odontogenic tumors were the commonest tumors. Early presentation must be encouraged since these tumors if presented early can be successfully treated.

Burkitt and Burkitt-Like Lymphomas: a Systematic Review

PURPOSE OF REVIEW

Burkitt's lymphoma and its leukemic form (Burkitt cell acute lymphoblastic leukemia) are a highly aggressive disease. We review the classification, clinical presentation, histology, cytogenetics, and the treatment of the disease.

RECENT FINDINGS

Burkitt's lymphoma might be associated with tumor lysis syndrome which is a potentially fatal complication that occurs spontaneously or upon initiation of chemotherapy. Major improvements were made in the treatment of pediatric and adults population using short-course dose-intensive chemotherapy regimens, usually 1 week after a prephase induction. Addition of Rituximab to chemotherapy has become a standard of care. Relapsed/refractory disease has a very poor prognosis and the benefit from autologous/allogeneic hematopoietic stem cell transplant remains uncertain. Rituximab-based short-course dose-intensive chemotherapy is the standard of care of Burkitt's lymphoma even in the immunodeficiency-related form.

Epstein barr virus IgG and EBER-1 in Burkitt's lymphoma children at a referral hospital in western Kenya

Burkitt's lymphoma (BL) is a frequent childhood B cell non-Hodgkin's lymphoma (NHL) in equatorial Africa associated with infections. Chronic Epstein Barr virus (EBV) infections can lead to host immune stimulation that may trigger genetic translocation(s), neoplastic transformation and proliferation of B cells. We determined EBV immunoglobulin G (IgG) in sera from participants and EBER-1 in tumour sections in confirmed BL cases at Moi Teaching and Referral Hospital (MTRH). A cross sectional study of children with clinical and histology diagnosis of NHL from whom BL status were confirmed by immunohistochemistry (IHC) was carried out. Epstein Barr virus IgG in sera was determine using Enzyme-linked immunosorbant assay, IHC for EBER-1 and MYC protein in tumour sections. Demographic and clinical information were obtained from questionnaires and hospital files respectively. Ninety three percent of sera were EBV IgG positive of which 31.7% were confirmed as BL. All jaw BL tumours and 86.7% of BL tumours carried EBER-1 antigen. Odds ratio of EBER-1 positive was 1.39, 95% CI: 0.16-12.19 in BL tumours regardless of age or gender. EBV infection among the study participants may be associated with BL, however, EBER-1 and MYC negative in BL tumours suggest alternative BL pathogenesis or variant.

Novel replisome-associated proteins at cellular replication forks in EBV-transformed B lymphocytes

Epstein-Barr virus (EBV) is an oncogenic herpesvirus and WHO class 1 carcinogen that resides in B lymphocytes of nearly all humans. While silent in most, EBV can cause endemic Burkitt lymphoma in children and post-transplant lymphoproliferative disorders/lymphomas in immunocompromised hosts. The pathogenesis of such lymphomas is multifactorial but to a large extent depends on EBV’s ability to aggressively drive cellular DNA replication and B cell proliferation despite cell-intrinsic barriers to replication. One such barrier is oncogenic replication stress which hinders the progression of DNA replication forks. To understand how EBV successfully overcomes replication stress, we examined cellular replication forks in EBV-transformed B cells using iPOND (isolation of Proteins on Nascent DNA)-mass spectrometry and identified several cellular proteins that had not previously been linked to DNA replication. Of eight candidate replisome-associated proteins that we validated at forks in EBV-transformed cells and Burkitt lymphoma-derived cells, three zinc finger proteins (ZFPs) were upregulated early in B cells newly-infected with EBV in culture as well as expressed at high levels in EBV-infected B blasts in the blood of immunocompromised transplant recipients. Expressed highly in S- and G2-phase cells, knockdown of each ZFP resulted in stalling of proliferating cells in the S-phase, cleavage of caspase 3, and cell death. These proteins, newly-identified at replication forks of EBV-transformed and Burkitt lymphoma cells therefore contribute to cell survival and cell cycle progression, and represent novel targets for intervention of EBV-lymphomas while simultaneously offering a window into how the replication machinery may be similarly modified in other cancers.

Cancer cells must overcome chronic replication stress, a central barrier to DNA replication. This is true also for cancers caused by Epstein-Barr virus (EBV). To understand how EBV overcomes this barrier to successfully drive cell proliferation, we isolated proteins associated with the cellular replication machinery in EBV-transformed B lymphocytes and identified several cellular proteins that had not previously been linked to DNA replication in cancer or healthy cells. Three of these were zinc finger proteins enriched at the replication machinery in EBV-transformed and EBV-positive Burkitt lymphoma-derived cells, upregulated in newly-infected B cells, and expressed at high levels in infected B cells from transplant recipients. These zinc finger proteins also contributed towards cell proliferation, survival, and cell cycle progression. While these proteins may also contribute to DNA replication in other cancers, they simultaneously represent potential targets in EBV-cancers, some of which are difficult to treat.

Immunoglobulin heavy variable (IgHV) gene mutation and micro-RNA expression in Burkitt's lymphoma at Moi Teaching and Referral Hospital in Western Kenya

INTRODUCTION

Burkitt's lymphoma (BL) is a virus associated childhood B-cell cancer common in Eastern Africa. Continued survival of B-cells in germinal centres depend on expression of high affinity immunoglobulins (Ig) to complementary antigens by somatic hypermutation of Ig genes. Cellular microRNAs, non-coding RNAs have been reported to play role in cell cycle regulation. Both viral antigen dependent mutation and micro-RNA expression maybe involved in BL pathogenesis.

OBJECTIVE

To describe immunoglobulin heavy variable (IgHV) rearrangement and micro-RNA expressions in BL tumours.

METHODS

Genomic DNA were extracted and purified from BL tissue blocks at Moi Teaching and Referral Hospital, before amplification using IgHV consensus primers and sequencing. The sequences were then aligned with germline alleles in IMGT/V-QUEST® database. Total RNA extracted from tissue blocks and cell lines were used to determine relative expression of hsamiR-34a and hsa-miR-127.

RESULTS

In all tumours, allele alignment scores and number of mutations range were 89.2-93.2%, 15-24 respectively. The range of IgHV amino acid changes were higher in EBER-1+ (15-25) than EBER-1- (9-15). In MYC+ tumours, the relative expression were: hsa-miR-127(2.09);hsa-miR-34a (2.8) and MYC- hsa-miR-127 (1.2), hsa-miR-34a (1.0).

CONCLUSION

B-cell in BL contained somatic mutated IgHV gene and upregulated cellular microRNAs with possible pathogenetic role(s).

Cancer in Kenya: types and infection-attributable. Data from the adult population of two National referral hospitals (2008-2012)

Background: Cancer in Africa is an emerging health problem. In Kenya it ranks third as a cause of death after infectious and cardiovascular diseases. Nearly 31% of the total cancer burden in sub-Saharan Africa is attributable to infectious agents. Information on cancer burden is scanty in Kenya and this study aimed to provide comprehensive hospital based data to inform policies. Method: A cross-sectional retrospective survey was conducted at Kenyatta National Hospital (KNH) and Moi Teaching and Referral Hospital (MTRH) from January 2008 to December 2012.  Data was obtained from the patients files and the study was approved by the KNH/University of Nairobi and MTRH Ethics and Research Committees.   Results: In KNH, the top five cancers were: cervical (62, 12.4%), breast (59, 11.8%), colorectal (31, 6.2%), chronic leukemia (27, 5.4%) and stomach cancer (26, 5.2%). Some 154 (30.8%) of these cancers were associated with infectious agents, while an estimated 138 (27.6%) were attributable to infections. Cancers of the cervix (62, 12.4%), stomach (26, 5.2%) and nasopharynx (17, 3.4%) were the commonest infection-associated cancers. In MTRH, the five common types of cancers were Kaposi's sarcoma (93, 18.6%), breast (77, 15.4%), cervical (41, 8.2%), non-Hodgkin's lymphoma (37, 7.4%) and colorectal, chronic leukemia and esophageal cancer all with 27 (5.4%). Some 241 (48.2%) of these cancers were associated with infectious agents, while an estimated 222 (44.4%) were attributable to infections. Kaposi's sarcoma (93, 18.6%), cancer of the cervix (41, 8.2%) and non-Hodgkin's lymphoma (37, 7.4%) were the commonest infection-associated cancers. Conclusion: Our results suggest that 30.8% and 48.2% of the total cancer cases sampled in KNH and MTRH respectively were associated with infectious agents, while 27.6% and 44.4% were attributable to infections in the two hospitals respectively. Reducing the burden of infection-attributable cancers can translate to a reduction of the overall cancer burden.

The burden of Burkitt lymphoma in Africa

BACKGROUND

Burkitt lymphoma (BL) is a relatively common cancer of childhood in tropical Africa, although its precise incidence and continent-wide geographic distribution have not been previously systematically studied.

METHODS

Using the methods employed to produce national estimates of cancer incidence for the "Globocan" series of the International Agency for Research on Cancer, along with detailed information on cancer incidence by histological subtype from cancer registries in Africa, we estimate the numbers and rates of incidence by sex, age group, country and region of Africa.

RESULTS

We estimate that the number of new cases that occurred in 2018 to be about 3900, two thirds in males, and 81% in children aged 0-14. On a national basis, the geographic distribution of incidence rates among children in sub-Saharan Africa resembles that of the prevalence of infection with Falciparum malaria. An estimated 81% of cases are associated with infection with Epstein Barr virus (EBV).

CONCLUSIONS

BL comprises almost 50% of childhood of non-Hodgkin lymphoma in Africa, almost all of which are associated with EBV, with the geographic distribution - at least in sub Saharan Africa - mediated by infection with malaria.

Evolutionary effects of the AID/APOBEC family of mutagenic enzymes on human gamma-herpesviruses

The human gamma-herpesviruses, Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, establish lifelong latency in B cells and are associated with multiple malignancies. Virus-host coevolution often drive changes in both host immunity and in the viral genome. We consider one host immune mechanism, the activation-induced deaminase (AID)/APOBEC family of cytidine deaminases, that induces mutations in viral DNA. AID, the ancestral gene in the family has a conserved role in somatic hypermutation, a key step in antibody affinity maturation. The APOBEC3 subfamily, of which there are seven genes in human, have evolved antiviral functions and have diversified in terms of their expression pattern, subcellular localization, and DNA mutation motifs (hotspots). In this study, we investigated how the human gamma-herpesviruses have evolved to avoid the action of the AID/APOBEC enzymes and determine if these enzymes are contributing to the ongoing evolution of the viruses. We used computational methods to evaluate observed versus expected frequency of AID/APOBEC hotspots in viral genomes and found that the viruses have evolved to limit the representation of AID and certain APOBEC3 motifs. At the same time, the remaining hotspots were highly likely to cause amino acid changes, suggesting prolonged evolutionary pressure of the enzymes on the viruses. To study current hypermutation, as opposed to historical mutation processes, we also analyzed putative mutations derived from alignments of published viral genomes and found again that AID and APOBEC3 appear to target the genome most frequently. New protein variants resulting from AID/APOBEC activity may have important consequences in health, including vaccine development (epitope evolution) and host immune evasion.

Whitehurst C, Qadri I, Shackelford J, Pagano JS, Muhammad D, Richards KL. Prevalence of Epstein–Barr Virus Genotypes in Pakistani Lymphoma Patients

The Epstein-Barr virus (EBV) is a herpesvirus infecting more than 90% of the human population. The tropism of EBV for B lymphocytes is evidenced in its association with many lymphoproliferative disorders. Different types of EBV (EBV-1 and EBV-2), classified on the basis of EBV nuclear antigen-2 (EBNA-2) genotyping, have been reported in benign and malignant pathologies, but there is almost no information about their frequency in the Pakistani population. The aim of this study was to determine the frequency and distribution of EBNA-2-based EBV genotypes in lymphoma patients. Genomic DNA was extracted from formalin-fixed paraffin embedded (FFPE) tissue samples obtained from 73 EBV-DNA-positive lymphoma patients. The β-globin gene was amplified to assess the presence and quality of cellular DNA from all samples. EBER-1 DNA was detected by PCR to confirm EBV presence in tissue samples. EBNA-1 mRNA relative quantification done by quantitative PCR substantiated EBNA-1 mRNA overexpression in 43.8% of EBV-positive cases in comparison to EBV-positive control cell line. EBNA-2 genotyping was done by nested PCR. Among typable samples, EBV-1 was found in 90.7% of samples while EBV-2 was present in 9.3% cases. These results show that EBV-1 was the most prevalent type in the lymphoma population of Pakistan. This epidemiology of EBV in Pakistani lymphoma patients represents an important first step in using EBV for prognosis and monitoring treatment response.

The increasing prevalence of non-communicable diseases in low-middle income countries: the view from Malawi

Non-communicable diseases (NCDs) are the leading cause of death globally, the majority of these being due to cardiovascular disease, cancer, chronic respiratory diseases, or diabetes. Mortality from many NCDs continues to increase worldwide, with a disproportionately larger impact in low-middle income countries (LMIs), where almost 75% of global deaths occur from these causes. As a low-income African country that consistently ranks amongst the world's poorest nations, Malawi as a case study demonstrates how transition due to societal change and increasing urbanization is often accompanied by a rise in the rate of NCDs. Other factors apart from changing lifestyle factors can explain at least some of this increase, such as the complex relationship between communicable and NCD and growing environmental, occupational, and cultural pressures. Malawi and other LMIs are struggling to manage the increasing challenge of NCDs, in addition to an already high communicable disease burden. However, health care policy implementation, specific health promotion campaigns, and further epidemiological research may be key to attenuating this impending health crisis, both in Malawi and elsewhere. This review aims to examine the effects of the major NCDs in Malawi to help inform future public health care policy in the region.

Pathology-Based Research in Africa

The process of conducting pathology research in Africa can be challenging. But the rewards in terms of knowledge gained, quality of collaborations, and impact on communities affected by infectious disease and cancer are great. This report reviews 3 different research efforts: fatal malaria in Malawi, mucosal immunity to HIV in South Africa, and cancer research in Uganda. What unifies them is the use of pathology-based approaches to answer vital questions, such as physiology, pathogenesis, predictors of clinical course, and diagnostic testing schemes.

Cytokines associated with Burkitt's lymphoma in western Kenya

Objective

Burkitt’s lymphoma (BL) is a common aggressive non-Hodgkin’s lymphoma in East and Central Africa among children. Persistent infections with Epstein Barr virus or Plasmodium falciparum are associated with immune hyperstimulation. It is hypothesised that inadvertent cytokine responses to infections indirectly or directly influence B cell neoplastic transformation through c-myelocytomatosis (c-myc) gene translocation. We sought to describe cytokines in children and adolescents with BL. Participants were recruited from western Kenya with parental consent, diagnosis confirmed using histology and consensus panel of immunohistochemistry antibodies. T helper1/2/17A and transforming growth factor-β1 (TGF-β1) cytokines were estimated using cytometric bead array in plasma. Complete blood counts (CBC) were determined by Beckman Coulter^®.

Results

Out of 104 enrolled participants, 32% were confirmed BL and 68% grouped as non-BL. Mean (pg/ml) levels of cytokines in BL and non-BL were: interleukin (IL)-6 100.3 and 39.4 p = 0.152; IL-10 11.5 and 12.5 p = 0.363; IL-17A 17.8 and 64.9 p = 0.094 respectively. Expressions of interferon-γ, IL-2 and tumour necrosis factor-α were low and TGF-β1 undetectable in both groups. Mean CBC differed between the two groups before and after chemotherapy, WBC being significantly so. Interleukin-6, IL-17A and IL-10 responses to infections in the study area may be associated with pathogenesis and be potential therapeutic targets.

High-throughput sequencing of the B-cell receptor in African Burkitt lymphoma reveals clues to pathogenesis

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.

[Burkitt's lymphoma of the oral cavity: about a case]

Burkitt's lymphoma (LB) is a type of malignant non-Hodgkin's lymphoma originating from malignant B-cell transformation and proliferation. Positive confirmation is based on biopsy of the tumor mass or bone marrow aspiration revealing the presence of tumor cells. We here report the case of a young man, about twenty years old, addressed for post tooth extraction gingival swellings evolving for 1 month. Anatomopathologic examination after biopsy complemented by immunohistochemistry confirmed the diagnosis of Burkitt's lymphoma. Treatment was based on chemotherapy. Although Burkitt's lymphoma is rare, it is an aggressive tumor that represents a real public health problem, hence the role of the dentists in early diagnosis, in order to allow rapid and appropriate management of the disease which is vital to the healing process.

Current Trends and Alternative Scenarios in EBV Research

Epstein-Barr virus (EBV) infection is associated with several distinct hematological and epithelial malignancies, e.g., Burkitt lymphoma, Hodgkin lymphoma, nasopharyngeal carcinoma, gastric carcinoma, and others. The association with several malignant tumors of local and worldwide distribution makes EBV one of the most important tumor viruses. Furthermore, because EBV can cause posttransplant lymphoproliferative disease, transplant medicine has to deal with EBV as a major pathogenic virus second only to cytomegalovirus. In this review, we summarize briefly the natural history of EBV infection and outline some of the recent advances in the pathogenesis of the major EBV-associated neoplasms. We present alternative scenarios and discuss them in the light of most recent experimental data. Emerging research areas including EBV-induced patho-epigenetic alterations in host cells and the putative role of exosome-mediated information transfer in disease development are also within the scope of this review. This book contains an in-depth description of a series of modern methodologies used in EBV research. In this introductory chapter, we thoroughly refer to the applications of these methods and demonstrate how they contributed to the understanding of EBV-host cell interactions. The data gathered using recent technological advancements in molecular biology and immunology as well as the application of sophisticated in vitro and in vivo experimental models certainly provided deep and novel insights into the pathogenetic mechanisms of EBV infection and EBV-associated tumorigenesis. Furthermore, the development of adoptive T cell immunotherapy has provided a novel approach to the therapy of viral disease in transplant medicine and hematology.

Parasite Infection, Carcinogenesis and Human Malignancy

Cancer may be induced by many environmental and physiological conditions. Infections with viruses, bacteria and parasites have been recognized for years to be associated with human carcinogenicity. Here we review current concepts of carcinogenicity and its associations with parasitic infections. The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic while the protozoan Trypanosoma cruzi, the causing agent of Chagas disease, has a dual role in the development of cancer, including both carcinogenic and anticancer properties. Although malaria per se does not appear to be causative in carcinogenesis, it is strongly associated with the occurrence of endemic Burkitt lymphoma in areas holoendemic for malaria. The initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by the Epstein-Barr virus. Observations suggest that Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas. This review provides an overview of the mechanisms of parasitic infection-induced carcinogenicity.

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The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic.

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Trypanosoma cruzi has a dual role in cancer development including both carcinogenic and anticancer properties.

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Initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by EBV.

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Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas.

We searched MEDLINE database and PubMed for articles from 1970 through June 30, 2016. Search terms used in various combinations were “parasite infection”, “carcinogenesis”, “cancer”, “human malignancy”, “parasite and cancer”, “infection-associated cancer”, “parasite-associated cancer” “schistosomiasis”, “opisthorchiasis”, “malaria”, “Chagas disease”, and “strongyloidiasis”. Articles resulting from these searches and relevant references cited in those articles were selected based on their related topics and were reviewed. Abstracts and reports from meetings were also included. Articles published in English were included.

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.

Early-life exposures to infectious agents and later cancer development

There is a growing understanding that several infectious agents are acquired in early life and this is the reason why available vaccines target the new born, infants, and adolescents. Infectious agents are associated with cancer development and it is estimated that about 20% of the world's cancer burden is attributed to infectious agents. There is a growing evidence that certain infectious agents acquired in early life can give rise to cancer development, but estimates of the cancer burden from this early‐life acquisition is unknown. In this article, we have selected five cancers (cervical, liver, Burkitt's lymphoma‐leukemia, nasopharyngeal carcinoma, and adult T‐cell leukemia‐lymphoma) and examine their links to infectious agents (HPV, HBV, HCV, EBV, and HTLV‐1) acquired in early life. For these agents, the acquisition in early life is from mother‐to‐child transmission, perinatal contact (with genital tract secretions, amniotic fluids, blood, and breast milk), saliva, sexual intercourse, and blood transfusion. We also discuss prevention strategies, address future directions, and propose mechanisms of action after a long latency period from the time of acquisition of the infectious agent in early life to cancer development.

Two hypotheses of dense breasts and viral infection for explaining incidence of breast cancer by age group in Korean women

Breast cancer, the second leading type of cancer in Korean women, has shown increasing incidence over the past 10 years. However, the curves of incidence by age group cast doubt on the birth cohort effect hypothesis. To explain the curves, here I suggest two alternative hypotheses of breast density and viral infection based on pre-existing evidences. Evaluating these hypotheses would require important clues to find unknown risk factors of breast cancer and to plan more effective strategies for breast cancer control in Korean women.

EBNA3C augments Pim-1 mediated phosphorylation and degradation of p21 to promote B-cell proliferation

Epstein–Barr virus (EBV), a ubiquitous human herpesvirus, can latently infect the human population. EBV is associated with several types of malignancies originating from lymphoid and epithelial cell types. EBV latent antigen 3C (EBNA3C) is essential for EBV-induced immortalization of B-cells. The Moloney murine leukemia provirus integration site (PIM-1), which encodes an oncogenic serine/threonine kinase, is linked to several cellular functions involving cell survival, proliferation, differentiation, and apoptosis. Notably, enhanced expression of Pim-1 kinase is associated with numerous hematological and non-hematological malignancies. A higher expression level of Pim-1 kinase is associated with EBV infection, suggesting a crucial role for Pim-1 in EBV-induced tumorigenesis. We now demonstrate a molecular mechanism which reveals a direct role for EBNA3C in enhancing Pim-1 expression in EBV-infected primary B-cells. We also showed that EBNA3C is physically associated with Pim-1 through its amino-terminal domain, and also forms a molecular complex in B-cells. EBNA3C can stabilize Pim-1 through abrogation of the proteasome/Ubiquitin pathway. Our results demonstrate that EBNA3C enhances Pim-1 mediated phosphorylation of p21 at the Thr¹⁴⁵ residue. EBNA3C also facilitated the nuclear localization of Pim-1, and promoted EBV transformed cell proliferation by altering Pim-1 mediated regulation of the activity of the cell-cycle inhibitor p21/WAF1. Our study demonstrated that EBNA3C significantly induces Pim-1 mediated proteosomal degradation of p21. A significant reduction in cell proliferation of EBV-transformed LCLs was observed upon stable knockdown of Pim-1. This study describes a critical role for the oncoprotein Pim-1 in EBV-mediated oncogenesis, as well as provides novel insights into oncogenic kinase-targeted therapeutic intervention of EBV-associated cancers.

The oncogenic serine/threonine kinase Pim-1 is upregulated in a number of human cancers including lymphomas, gastric, colorectal and prostate carcinomas. EBV nuclear antigen 3C (EBNA3C) is essential for EBV-induced transformation of human primary B-lymphocytes. Our current study revealed that EBNA3C significantly enhances Pim-1 kinase expression at both the transcript and protein levels. EBNA3C also interacts with Pim-1 and can form a complex in EBV-transformed cells. Moreover, EBNA3C increases nuclear localization of Pim-1 and stabilizes Pim-1 protein levels by inhibiting its poly-ubiquitination. Additionally, EBNA3C augments Pim-1 mediated phosphorylation of p21 and its proteosomal degradation. Stable knockdown of Pim-1 using si-RNA showed a significant decrease in proliferation of EBV transformed lymphoblastoid cell lines and subsequent induction of apoptosis by triggering the intrinsic apoptotic pathway. Therefore, our study demonstrated a new mechanism by which the oncogenic Pim-1 kinase targeted by EBV latent antigen 3C can inhibit p21 function, and is therefore a potential therapeutic target for the treatment of EBV-associated malignancies.

Interleukin-6 and interleukin-10 gene promoter polymorphisms and risk of endemic Burkitt lymphoma

Overexpression of interleukin-6 (IL-6) and IL-10 in endemic Burkitt lymphoma (eBL) may facilitate tumorigenesis by providing a permissive cytokine milieu. Promoter polymorphisms influence interindividual differences in cytokine production. We hypothesized that children genetically predisposed for elevated cytokine levels may be more susceptible to eBL. Using case-control samples from western Kenya consisting of 117 eBL cases and 88 ethnically matched healthy controls, we tested for the association between eBL risk and IL-10 (rs1800896, rs1800871, and rs1800872) and IL-6 (rs1800795) promoter single nucleotide polymorphisms (SNPs) as well as IL-10 promoter haplotypes. In addition, the association between these variants and Epstein Barr Virus (EBV) load was examined. Results showed that selected IL-10 and IL-6 promoter SNPs and IL-10 promoter haplotypes were not associated with risk eBL or EBV levels in EBV-seropositive children. Findings from this study reveal that common variants within the IL-10 and IL-6 promoters do not independently increase eBL risk in this vulnerable population.

Maxillary sporadic Burkitt's lymphoma associated with neuro-orbital involvement in an Indian male

Burkitt's lymphoma (BL) is the fastest growing malignancy of the lymphoreticular system to affect humans and has a potential ability to double in size every day. A case of maxillary sporadic BL (sBL) associated with neuro-orbital involvement in an Indian male is presented. sBL initially presented as maxillary swelling with no obvious dental and periodontal changes. Histological specimen from incisional biopsy revealed a round cell malignant tumor and immunohistochemistry reactions favored nonHodgkin's lymphoma consistent with BL. Four weeks later, patient presented with orbital involvement as diplopia, sixth cranial nerve palsy, and medial rectus palsy. Chemotherapy regimen according to LMB 89 protocol was started. During chemotherapy regimen patient showed bradycardia and Babinski response, suggestive of central nervous system involvement. sBL associated with orbital involvement is extremely rare and only seven cases have been reported. Our case showed unusual presentation; despite the aggressive tumor did not show any common clinical, radiological, and hematological findings. We also discussed the role of oral medicine specialist, importance of early diagnosis, and prompt referral in management of maxillary sBL.

Factors influencing time to diagnosis and initiation of treatment of endemic Burkitt Lymphoma among children in Uganda and western Kenya: a cross-sectional survey

Background

Survival rates for children diagnosed with Burkitt lymphoma (BL) in Africa are far below those achieved in developed countries. Late stage of presentation contributes to poor prognosis, therefore this study investigated factors leading to delays in BL diagnosis and treatment of children in Uganda and western Kenya.

Methods

Guardians of children diagnosed with BL were interviewed at the Jaramogi Oginga Odinga Teaching and Referral Hospital (JTRH) and Uganda Cancer Institute (UCI) from Jan-Dec 2010. Information on sociodemographics, knowledge, attitudes, illness perceptions, health-seeking behaviors and prior health encounters was collected using a standardized, pre-tested questionnaire.

Results

Eighty-two guardians were interviewed (20 JTRH, 62 UCI). Median "total delay" (1st symptoms to BL diagnosis) was 12.1 weeks [interquartile range (IQR) 4.9-19.9] in Kenya and 12.9 weeks (IQR 4.3-25.7) in Uganda. In Kenya, median "guardian delay" (1st symptoms to 1st health encounter) and "health system delay" (1st health encounter to BL diagnosis) were 9.0 weeks (IQR 3.6-15.7) and 2.0 weeks (IQR 1.6-5.8), respectively. Data on guardian and health system delay in Uganda were only available for those with < 4 prior health encounters (n = 26). Of these, median guardian delay was 4.3 weeks (range 0.7-149.9), health system delay 2.6 weeks (range 0.1-16.0), and total delay 10.7 weeks (range 1.7-154.3). Guardians in Uganda reported more health encounters than those in Kenya (median 5, range 3–16 vs. median 3, range 2–6). Among Kenyan guardians, source of income was the only independent predictor of delay, whereas in Uganda, guardian delay was influenced by guardians’ beliefs on the curability of cancer, health system delay, by guardians’ perceptions of cancer as a contagious disease, and total delay, by the number of children in the household and guardians’ role as caretaker. Qualitative findings suggest financial costs, transportation, and other household responsibilities were major barriers to care.

Conclusions

Delays from symptom onset to BL treatment were considerable given the rapid growth rate of this cancer, with guardian delay constituting the majority of total delay in both settings. Future interventions should aim to reduce structural barriers to care and increase awareness of BL in particular and cancer in general within the community, as well as among health professionals.

Pediatric malignancies in Kano, Northern Nigeria

BACKGROUND

With effective immunization control of several devastating childhood infections in the developing world, non-infectious diseases such as malignancies have become increasingly important causes of pediatric morbidity and mortality. Therefore this 10-year retrospective study was undertaken to evaluate and document the pattern of childhood cancers in our locality.

METHODS

We reviewed 438 childhood (≤15 years) malignancies diagnosed at the histopathology and hematology laboratories of our teaching hospital in a 10-year period (2001-2010).

RESULTS

The 438 malignancies comprised 10.9% of all cancers. The maligancies frequently seen in early childhood (0-4 years) accounted for 46.1% and in late childhood (5-9 years) for 34.7%. Retinoblastoma (30.6%), Burkitt lymphoma (19.9%) and acute leukemia (16.9%) were the most common pediatric cancers. Unlike in most other parts of the world, acute myeloid leukemia was slightly more prevalent than acute lymphoblastic leukemia.

CONCLUSIONS

Although there were notable differences, our findings were in broad agreement with those of most other sub-Saharan African series, but differed markedly from those in the Western world and other high income countries. Further studies are required to identify the environmental factors for the high prevalence of nonfamilial retinoblastoma and possibly acute myeloid leukemia.

Parasites and malignancies, a review, with emphasis on digestive cancer induced by Cryptosporidium parvum (Alveolata: Apicomplexa)

The International Agency for Research on Cancer (IARC) identifies ten infectious agents (viruses, bacteria, parasites) able to induce cancer disease in humans. Among parasites, a carcinogenic role is currently recognized to the digenetic trematodes Schistosoma haematobium, leading to bladder cancer, and to Clonorchis sinensis or Opisthorchis viverrini, which cause cholangiocarcinoma. Furthermore, several reports suspected the potential association of other parasitic infections (due to Protozoan or Metazoan parasites) with the development of neoplastic changes in the host tissues. The present work shortly reviewed available data on the involvement of parasites in neoplastic processes in humans or animals, and especially focused on the carcinogenic power of Cryptosporidium parvum infection. On the whole, infection seems to play a crucial role in the etiology of cancer.

Etiopathogenesis of Burkitt's lymphoma: a lesson from a BL-like in CD1 mouse immune to Plasmodium yoelii yoelii

Introduction

There is a jaw cancer that develops in children five to eight years old in holoendemic malaria regions of Africa, associated to malaria and Epstein Barr virus infections (EBV). This malignancy is known as endemic Burkitt's lymphoma, and histopatologically is characterized by a starry sky appearance. To date, no histopathologic expression of Burkitt's lymphoma has been reported in non-genetically manipulated experimental animals. The purpose of the study is to describe the case of a mouse immune to Plasmodium yoelii yoelii (Pyy) that developed a Burkitt's lymphoma-like neoplasm after repeated malaria infections.

Results

Immune mouse 10 (IM-10) developed neoplasms at eight months of age, after receiving three Pyy inoculations. At autopsy eight subcutaneous tumors were found of which the right iliac fosse tumor perforated the abdominal wall and invaded the colon. The histopathologic study showed that all neoplasms were malignant lymphomas of large non-cleaved cells also compatible with variants or previous states of development of a Burkitt's lymphoma-like. The thymus, however, showed a typical starry sky Burkitt's lymphoma-like neoplasm.

Conclusions

Neoplasm development in CD1 mouse is associated to both, immunity against malaria and continuous antigenic stimulation with living parasites.

It is the first observation of a histopathologically expressed Human Burkitt's lymphoma-like neoplasm in a non-genetically manipulated mouse.

Chronic immune response associated to neoplasms development could probably be not an exclusive expression of malaria-host interaction but, it could be a pattern that can bee applied also to other agent-host interactions such as host-bacteria, fungus, virus and other parasites.

Nonparametric evaluation of dynamic disease risk: a spatio-temporal kernel approach

Quantifying the distributions of disease risk in space and time jointly is a key element for understanding spatio-temporal phenomena while also having the potential to enhance our understanding of epidemiologic trajectories. However, most studies to date have neglected time dimension and focus instead on the "average" spatial pattern of disease risk, thereby masking time trajectories of disease risk. In this study we propose a new idea titled "spatio-temporal kernel density estimation (stKDE)" that employs hybrid kernel (i.e., weight) functions to evaluate the spatio-temporal disease risks. This approach not only can make full use of sample data but also "borrows" information in a particular manner from neighboring points both in space and time via appropriate choice of kernel functions. Monte Carlo simulations show that the proposed method performs substantially better than the traditional (i.e., frequency-based) kernel density estimation (trKDE) which has been used in applied settings while two illustrative examples demonstrate that the proposed approach can yield superior results compared to the popular trKDE approach. In addition, there exist various possibilities for improving and extending this method.

A grander challenge: the case of how Makerere University College of Health Sciences (MakCHS) contributes to health outcomes in Africa

BACKGROUND

"Grand challenges" in global health have focused on discovery and development of technologies to save lives. The "grander challenge" involves building institutions, systems, capacity and demand to effectively deliver strategies to improve health. In 2008, Makerere University began a radical institutional change to bring together four schools under one College of Health Sciences. This paper's objective is to demonstrate how its leadership in training, research, and services can improve health in Uganda and internationally, which lies at the core of the College's vision.

METHODS

A comprehensive needs assessment involved five task forces that identified MakCHS's contribution to the Ugandan government health priorities. Data were collected through analysis of key documents; systematic review of MakCHS publications and grants; surveys of patients, students and faculty; and key informant interviews of the College's major stakeholders. Four pilot projects were conducted to demonstrate how the College can translate research into policy and practice, extend integrated outreach community-based education and service, and work with communities and key stakeholders to address their priority health problems.

RESULTS

MakCHS inputs to the health sector include more than 600 health professionals graduating per year through 23 degree programs, many of whom assume leadership positions. MakCHS contributions to processes include strengthened approaches to engaging communities, standardized clinical care procedures, and evidence-informed policy development. Outputs include the largest number of outpatients and inpatient admissions in Uganda. From 2005-2009, MakCHS also produced 837 peer-reviewed research publications (67% in priority areas). Outcomes include an expanded knowledge pool, and contributions to coverage of health services and healthy behaviors. Impacts include discovery and applications of global significance, such as the use of nevirapine to prevent HIV transmission in childbirth and male circumcision for HIV prevention. Pilot projects have applied innovative demand and supply incentives to create a rapid increase in safe deliveries (3-fold increase after 3 months), and increased quality and use of HIV services with positive collateral improvements on non-HIV health services at community clinics.

CONCLUSION

MakCHS has made substantial contributions to improving health in Uganda, and shows great potential to enhance this in its new transformational role - a model for other Universities.

Uncertainty in mapping malaria epidemiology: implications for control

Malaria is a location-specific, dynamic infectious disease transmitted by mosquitoes to humans and is influenced by environmental, vector, parasite, and host factors. The principal purposes of malarial epidemiology are 1) to describe the malarial distribution in space and time along with the physical, biologic, and social etiologic factors and 2) to guide control objectives for either modeling impact or measuring progress of control tactics. Mapping malaria and many of its causative factors has been achieved on many different levels from global distribution to biologic quantitative trait localization in humans, parasites, and mosquitoes. Despite these important achievements, a large degree of uncertainty still exists on the annual burden of malarial cases. Accurate, sensitive detection and treatment of asymptomatic reservoirs important to infectious transmission are additional components necessary for future control measures. Presently spurred by the leadership and funding of Bill and Melinda Gates, the malarial community is developing and implementing plans for elimination of malaria. The challenge for malariologists is to digitally integrate and map epidemiologic factors and intervention measures in space and time to target effective, sustainable control alongside research efforts.

Epstein-Barr virus in Burkitt's lymphoma: a role for latent membrane protein 2A

Burkitt's lymphoma (BL) is characterized by translocation of the MYC gene to an immunoglobulin locus. Transgenic mouse models have been used to study the molecular changes that are necessary to bypass tumor suppression in the presence of translocated MYC. Inactivation of the p53 pathway is a major step to tumor formation in mouse models that is also seen in human disease. Human BL is often highly associated with Epstein-Barr virus (EBV). The EBV latency protein latent membrane protein 2A (LMP2A) is known to promote B cell survival by affecting levels of pro-survival factors. Using LMP2A transgenic mouse models, we have identified a novel mechanism that permits lymphomagenesis in the presence of an intact p53 pathway. This work uncovers a contribution of EBV to molecular events that have documented importance in BL pathogenesis, and may underlie the poorly understood link between EBV and BL.

Case report. Primary hypothalamic third ventriclular Burkitt's lymphoma: a case report with emphasis on differential diagnosis

A patient with primary Burkitt-type lymphoma of the central nervous system is presented. A hypothalamic-third ventricular tumour in a man 71 years of age was diagnosed histologically as Burkitt's lymphoma. Primary Burkitt's lymphoma of the hypothalamic region is extremely rare and has not been previously reported in adults.

pRb2/p130 protein expression and RBL2 mutation analysis in Burkitt lymphoma from Uganda

Background

The members of the retinoblastoma protein family, pRb, p107 and pRb2 (p130), are central players in controlling the cell cycle. Whereas disturbed function of pRb is commonly seen in human cancers, it is still an open question whether pRb2 is involved in tumorigenic processes. However, altered subcellular localization of pRb2 and mutations in the pRb2-encoding gene RBL2 have been described for some tumours, including Burkitt lymphomas (BL).

Methods

We retrieved 51 biopsy specimens of endemic BL cases from Uganda. The expression of pRb2 was determined by immunohistochemistry. Exons 19-22 of the RBL2 gene, the region known to contain a nuclear localization signal, were screened for mutations by PCR amplification and direct DNA sequencing.

Results

Nearly all of our cases (84.0%) were positive for pRb2 protein expression although this protein is a marker for growth arrest and Burkitt lymphoma is characterized by a high proliferation rate. Of the positive cases, 73.8% were scored as expressing the protein at a high level. Subcellular pRb2 localization was predominantly nuclear and no cases with expression restricted to the cytoplasm were observed. We did not detect any RBL2 mutations in the part of the gene that encodes the C-terminal end of the protein.

Conclusion

The majority of endemic BL cases from Uganda express pRb2, but somatic RBL2 mutations affecting the protein's nuclear localization signal appear to be rare.

Increased frequency of hematopoietic malignancies in relatives of patients with lymphoid neoplasms: a French case-control study

Lymphoid neoplasms (LNs), including non-Hodgkin's lymphoma (NHL), Hodgkin's lymphoma (HL), lymphoproliferative syndrome (LPS) and multiple myeloma (MM), are among the most frequent cancers ( approximately 17,000 new cases per year in France), after those related to smoking. LNs were investigated using the data from the ENGELA study. ENGELA is a multicenter hospital-based case-control study that was carried out in France over the period September 2000-December 2004. In all, 822 cases (397 NHL, 149 LH, 168 SLP and 108 MM) and 752 controls were included and described 5,481 and 5,188 first-degree relatives, respectively. A positive association with a familial history of hematopoietic cancer was observed for LN (OR = 1.7 [1.0-2.8]) overall and for LPS (OR = 3.2 [1.4-6.8]). The associations with HL (OR = 10.4 [2.0-53.8]) and NHL (OR = 2.4 [1.0-5.9]) were stronger for men. The associations were also stronger when the disease had been diagnosed before the relatives were aged 45 years. The results mainly support the involvement of genetic factors and suggest that at least some of those factors may be sex-linked. However, the slight overrepresentation of affected spouses among the cases might also support the responsibility of environmental factors.