Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
Commun Biol ; 7(1): 41, 2024 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-38182727

RESUMO

Burkitt lymphoma (BL) is responsible for many childhood cancers in sub-Saharan Africa, where it is linked to recurrent or chronic infection by Epstein-Barr virus or Plasmodium falciparum. However, whether human leukocyte antigen (HLA) polymorphisms, which regulate immune response, are associated with BL has not been well investigated, which limits our understanding of BL etiology. Here we investigate this association among 4,645 children aged 0-15 years, 800 with BL, enrolled in Uganda, Tanzania, Kenya, and Malawi. HLA alleles are imputed with accuracy >90% for HLA class I and 85-89% for class II alleles. BL risk is elevated with HLA-DQA1*04:01 (adjusted odds ratio [OR] = 1.61, 95% confidence interval [CI] = 1.32-1.97, P = 3.71 × 10-6), with rs2040406(G) in HLA-DQA1 region (OR = 1.43, 95% CI = 1.26-1.63, P = 4.62 × 10-8), and with amino acid Gln at position 53 versus other variants in HLA-DQA1 (OR = 1.36, P = 2.06 × 10-6). The associations with HLA-DQA1*04:01 (OR = 1.29, P = 0.03) and rs2040406(G) (OR = 1.68, P = 0.019) persist in mutually adjusted models. The higher risk rs2040406(G) variant for BL is associated with decreased HLA-DQB1 expression in eQTLs in EBV transformed lymphocytes. Our results support the role of HLA variation in the etiology of BL and suggest that a promising area of research might be understanding the link between HLA variation and EBV control.


Assuntos
Linfoma de Burkitt , Infecções por Vírus Epstein-Barr , Criança , Humanos , Linfoma de Burkitt/genética , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/genética , Herpesvirus Humano 4/genética , Cadeias alfa de HLA-DQ/genética
2.
Am J Hematol ; 99(1): 113-123, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38009642

RESUMO

Burkitt lymphoma (BL) is an aggressive B-cell lymphoma that significantly contributes to childhood cancer burden in sub-Saharan Africa. Plasmodium falciparum, which causes malaria, is geographically associated with BL, but the evidence remains insufficient for causal inference. Inference could be strengthened by demonstrating that mendelian genes known to protect against malaria-such as the sickle cell trait variant, HBB-rs334(T)-also protect against BL. We investigated this hypothesis among 800 BL cases and 3845 controls in four East African countries using genome-scan data to detect polymorphisms in 22 genes known to affect malaria risk. We fit generalized linear mixed models to estimate odds ratios (OR) and 95% confidence intervals (95% CI), controlling for age, sex, country, and ancestry. The ORs of the loci with BL and P. falciparum infection among controls were correlated (Spearman's ρ = 0.37, p = .039). HBB-rs334(T) was associated with lower P. falciparum infection risk among controls (OR = 0.752, 95% CI 0.628-0.9; p = .00189) and BL risk (OR = 0.687, 95% CI 0.533-0.885; p = .0037). ABO-rs8176703(T) was associated with decreased risk of BL (OR = 0.591, 95% CI 0.379-0.992; p = .00271), but not of P. falciparum infection. Our results increase support for the etiological correlation between P. falciparum and BL risk.


Assuntos
Linfoma de Burkitt , Malária Falciparum , Malária , Traço Falciforme , Humanos , África Oriental , Alelos , Linfoma de Burkitt/epidemiologia , Linfoma de Burkitt/genética , Malária Falciparum/epidemiologia , Malária Falciparum/genética , Malária Falciparum/complicações , Traço Falciforme/epidemiologia , Traço Falciforme/genética , Traço Falciforme/complicações , Nectinas/metabolismo
3.
Nat Commun ; 14(1): 8081, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38057307

RESUMO

In high-income countries, mosaic chromosomal alterations in peripheral blood leukocytes are associated with an elevated risk of adverse health outcomes, including hematologic malignancies. We investigate mosaic chromosomal alterations in sub-Saharan Africa among 931 children with Burkitt lymphoma, an aggressive lymphoma commonly characterized by immunoglobulin-MYC chromosomal rearrangements, 3822 Burkitt lymphoma-free children, and 674 cancer-free men from Ghana. We find autosomal and X chromosome mosaic chromosomal alterations in 3.4% and 1.7% of Burkitt lymphoma-free children, and 8.4% and 3.7% of children with Burkitt lymphoma (P-values = 5.7×10-11 and 3.74×10-2, respectively). Autosomal mosaic chromosomal alterations are detected in 14.0% of Ghanaian men and increase with age. Mosaic chromosomal alterations in Burkitt lymphoma cases include gains on chromosomes 1q and 8, the latter spanning MYC, while mosaic chromosomal alterations in Burkitt lymphoma-free children include copy-neutral loss of heterozygosity on chromosomes 10, 14, and 16. Our results highlight mosaic chromosomal alterations in sub-Saharan African populations as a promising area of research.


Assuntos
Linfoma de Burkitt , Masculino , Criança , Humanos , Linfoma de Burkitt/genética , Linfoma de Burkitt/patologia , Gana , Aberrações Cromossômicas , Leucócitos/patologia , Imunoglobulinas/genética , Translocação Genética
4.
J Interferon Cytokine Res ; 43(9): 394-402, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37366802

RESUMO

Interferon lambda 4 (IFN-λ4) is a novel type-III interferon that can be expressed only by carriers of the genetic variant rs368234815-dG within the first exon of the IFNL4 gene. Genetic inability to produce IFN-λ4 (in carriers of the rs368234815-TT/TT genotype) has been associated with improved clearance of hepatitis C virus (HCV) infection. The IFN-λ4-expressing rs368234815-dG allele (IFNL4-dG) is most common (up to 78%) in West sub-Saharan Africa (SSA), compared to 35% of Europeans and 5% of individuals from East Asia. The negative selection of IFNL4-dG outside Africa suggests that its retention in African populations could provide survival benefits, most likely in children. To explore this hypothesis, we conducted a comprehensive association analysis between IFNL4 genotypes and the risk of childhood Burkitt lymphoma (BL), a lethal infection-associated cancer most common in SSA. We used genetic, epidemiologic, and clinical data for 4,038 children from the Epidemiology of Burkitt Lymphoma in East African Children and Minors (EMBLEM) and the Malawi Infections and Childhood Cancer case-control studies. Generalized linear mixed models fit with the logit link controlling for age, sex, country, P. falciparum infection status, population stratification, and relatedness found no significant association between BL risk and 3 coding genetic variants within IFNL4 (rs368234815, rs117648444, and rs142981501) and their combinations. Because BL occurs in children 6-9 years of age who survived early childhood infections, our results suggest that additional studies should explore the associations of IFNL4-dG allele in younger children. This comprehensive study represents an important baseline in defining the health effects of IFN-λ4 in African populations.


Assuntos
Linfoma de Burkitt , Hepatite C , Pré-Escolar , Criança , Humanos , Linfoma de Burkitt/genética , Genótipo , Hepatite C/complicações , Hepatite C/genética , Hepacivirus/genética , África Oriental , Interleucinas/genética , Interleucinas/farmacologia , Polimorfismo de Nucleotídeo Único
5.
Clin Infect Dis ; 73(Suppl_5): S382-S389, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34910181

RESUMO

BACKGROUND: Intestinal disorders such as environmental enteric dysfunction (EED) are prevalent in low- and middle-income countries (LMICs) and important contributors to childhood undernutrition and mortality. Autopsies are rarely performed in LMICs but minimally invasive tissue sampling is increasingly deployed as a more feasible and acceptable procedure, although protocols have been devoid of intestinal sampling to date. We sought to determine (1) the feasibility of postmortem intestinal sampling, (2) whether autolysis precludes enteric biopsies' utility, and (3) histopathologic features among children who died during hospitalization with acute illness or undernutrition. METHODS: Transabdominal needle and endoscopic forceps upper and lower intestinal sampling were conducted among children aged 1 week to 59 months who died while hospitalized in Blantyre, Malawi. Autolysis ratings were determined for each hematoxylin and eosin slide, and upper and lower intestinal scoring systems were adapted to assess histopathologic features and their severity. RESULTS: Endoscopic and transabdominal sampling procedures were attempted in 28 and 14 cases, respectively, with >90% success obtaining targeted tissue. Varying degrees of autolysis were present in all samples and precluded histopathologic scoring of 6% of 122 biopsies. Greater autolysis in duodenal samples was seen with longer postmortem interval (Beta = 0.06, 95% confidence interval, 0.02-0.11). Histopathologic features identified included duodenal Paneth and goblet cell depletion. Acute inflammation was absent but chronic inflammation was prevalent in both upper and lower enteric samples. Severe chronic rectal inflammation was identified in children as young as 5.5 weeks. CONCLUSIONS: Minimally invasive postmortem intestinal sampling is feasible and identifies histopathology that can inform mortality contributors.


Assuntos
Desnutrição , Autopsia/métodos , Biópsia , Criança , Humanos , Lactente , Pobreza , Manejo de Espécimes
6.
Cancers (Basel) ; 13(7)2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33918470

RESUMO

BACKGROUND: Endemic Burkitt lymphoma (eBL) is the most common childhood cancer in Africa and is linked to Plasmodium falciparum (Pf) malaria infection, one of the most common and deadly childhood infections in Africa; however, the role of Pf genetic diversity is unclear. A potential role of Pf genetic diversity in eBL has been suggested by a correlation of age-specific patterns of eBL with the complexity of Pf infection in Ghana, Uganda, and Tanzania, as well as a finding of significantly higher Pf genetic diversity, based on a sensitive molecular barcode assay, in eBL cases than matched controls in Malawi. We examined this hypothesis by measuring diversity in Pf-serine repeat antigen-5 (Pfsera5), an antigenic target of blood-stage immunity to malaria, among 200 eBL cases and 140 controls, all Pf polymerase chain reaction (PCR)-positive, in Malawi. METHODS: We performed Pfsera5 PCR and sequencing (~3.3 kb over exons II-IV) to determine single or mixed PfSERA5 infection status. The patterns of Pfsera5 PCR positivity, mixed infection, sequence variants, and haplotypes among eBL cases, controls, and combined/pooled were analyzed using frequency tables. The association of mixed Pfsera5 infection with eBL was evaluated using logistic regression, controlling for age, sex, and previously measured Pf genetic diversity. RESULTS: Pfsera5 PCR was positive in 108 eBL cases and 70 controls. Mixed PfSERA5 infection was detected in 41.7% of eBL cases versus 24.3% of controls; the odds ratio (OR) was 2.18, and the 95% confidence interval (CI) was 1.12-4.26, which remained significant in adjusted results (adjusted odds ratio [aOR] of 2.40, 95% CI of 1.11-5.17). A total of 29 nucleotide variations and 96 haplotypes were identified, but these were unrelated to eBL. CONCLUSIONS: Our results increase the evidence supporting the hypothesis that infection with mixed Pf infection is increased with eBL and suggest that measuring Pf genetic diversity may provide new insights into the role of Pf infection in eBL.

7.
Cancer Epidemiol ; 67: 101748, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32562888

RESUMO

BACKGROUND: Human leukocyte antigens (HLA) are encoded by closely linked genetic loci, and are important in cervical carcinogenesis. The association between HLA-DRB1 alleles with cervical cancer has been studied extensively, but results reported thus far have been inconsistent. Hence, we performed a meta-analysis to precisely assess this association. METHODS: A literature search was conducted in various online databases to identify suitable articles. Case-control studies investigating the association between HLA-DRB1 alleles and cervical cancer were included in this study. Fixed and random-effect models were used to calculate the pooled odds ratio (OR) and 95% confidence intervals (CIs). RESULTS: A total of 6645 cases and 9095 controls from 36 case-control studies were included. Of the 13 HLA-DRB1 family alleles, DRB1*09 (OR = 1.30) and DRB1 *15 (OR = 1.60) were associated with cervical cancer risk, whilst DRB1*13 (OR = 0.66) exerted a protective effect. Among the 44 HLA-DRB1 specific alleles, DRB1*04:01 (OR = 1.25), DRB1*10:01 (OR = 1.45), DRB1*11:01 (OR = 1.32), DRB1*15:01 (OR = 1.21) and DRB1*15:02 (OR = 1.55) were associated with an increased risk of cervical cancer. However, DRB1*04:06 (OR = 0.52), DRB1*12:02 (OR = 0.61), DRB1*13:01 (OR = 0.62), DRB1*13:02 (OR = 0.57), and DRB1*14:04 (OR = 0.37) were associated with a decreased risk of cervical cancer. Subgroup analysis also revealed that HLA-DRB1 alleles are associated with cervical cancer in Asian, Caucasian, Hispanic or Latin American and black sub-Saharan Africa populations. CONCLUSION: Our meta-analysis revealed that multiple HLA-DRB1 alleles are associated with cervical cancer in women of diverse ancestry populations.


Assuntos
Etnicidade/genética , Predisposição Genética para Doença , Cadeias HLA-DRB1/genética , Neoplasias do Colo do Útero/epidemiologia , Neoplasias do Colo do Útero/genética , Alelos , Estudos de Casos e Controles , Feminino , Saúde Global , Humanos , Neoplasias do Colo do Útero/imunologia
8.
Pediatr Blood Cancer ; 67(9): e28383, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32391983

RESUMO

INTRODUCTION: The Collaborative Wilms Tumour (WT) Africa Project implemented an adapted WT treatment guideline in six centres in sub-Saharan Africa. The primary objectives were to describe abandonment of treatment, death during treatment, event-free survival (EFS) and relapse following implementation. An exploratory objective was to compare outcomes with the baseline evaluation, a historical cohort preceding implementation. METHODS: The Collaborative WT Africa Project is a multi-centre prospective clinical trial that began in 2014. Funding was distributed to all participating centres and used to cover treatment, travel and other associated costs for patients. Patient characteristics, tumour characteristics and events were described. RESULTS: In total, 201 WT patients were included. Two-year EFS was 49.9 ± 3.8% when abandonment of treatment was considered an event. Relapse of disease occurred in 21% (42 of 201) of all included patients and in 26% (42 of 161) of those who had a nephrectomy. Programme implementation was associated with significantly higher survival without evidence of disease at the end of treatment (52% vs 68.5%, P = .002), significantly reduced abandonment of treatment (23% vs 12%, P = .009) and fewer deaths during treatment (21% vs 13%, P = .06). CONCLUSION: This collaborative implementation of an adapted WT treatment guideline, using relatively simple and low-cost interventions, was feasible. Two-year EFS was almost 50%. In addition, a significant decrease in treatment abandonment and an increase in survival at the end of treatment were observed compared to a pre-implementation cohort. Future work should focus on decreasing deaths during treatment and will include enhancing supportive care.


Assuntos
Neoplasias Renais/mortalidade , Neoplasias Renais/cirurgia , Nefrectomia , Tumor de Wilms/mortalidade , Tumor de Wilms/cirurgia , Adolescente , África Subsaariana/epidemiologia , Criança , Pré-Escolar , Intervalo Livre de Doença , Feminino , Humanos , Lactente , Masculino , Estudos Prospectivos , Taxa de Sobrevida
9.
Trop Med Int Health ; 25(6): 666-672, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32233050

RESUMO

OBJECTIVE: TP53 plays a crucial role in preventing cancer development. Previous studies in sub-Saharan Africa (SSA) reported inconclusive findings for the association of the TP53 rs1042522 C > G variant with cervical cancer. We therefore performed a meta-analysis to summarise this association in the SSA population. METHODS: Online databases were searched to identify suitable articles according to the PRISMA guidelines. We included studies published in English or French that provided the sample sizes and genotype counts for both cases and controls and evaluated the association between TP53 rs1042522 and cervical cancer in the SSA population. A fixed-effect model was used to calculate the pooled odds ratio (OR) and 95% confidence intervals (95% CIs). RESULTS: A total of 699 cervical cancer cases and 1008 controls from eight studies in SSA were included in this meta-analysis. Women harbouring the variant G allele of the TP53 rs1042522 were at increased risk of cervical cancer in allelic (G vs. C; OR = 1.30, 95% Cl = 1.12-1.50), homozygous (GG vs. CC; OR = 1.62, 95% CI = 1.20-2.19) and recessive (GG vs. CG + GG; OR = 1.74, 95% CI = 1.34-2.25) genetic models. However, the dominant genetic model (CG + GG vs. CC; OR = 1.20, 95% CI = 0.96-1.48) was not significantly associated with cervical cancer. CONCLUSIONS: Our meta-analysis revealed that harbouring variant G allele of TP53 rs1042522 is associated with cervical cancer risk in the SSA population.


OBJECTIF: Le TP53 joue un rôle crucial dans la prévention du développement du cancer. Des études antérieures en Afrique subsaharienne (ASS) ont rapporté des résultats non concluants pour l'association de la variante TP53 rs1042522 C>G avec le cancer du col de l'utérus. Nous avons donc réalisé une méta-analyse pour résumer cette association dans la population SSA. MÉTHODES: Les bases de données en ligne ont été recherchées pour identifier les articles appropriés selon les directives PRISMA. Nous avons inclus des études publiées en anglais ou en français qui ont fourni la taille des échantillons et le nombre de génotypes pour les cas et les témoins et évalué l'association entre TP53 rs1042522 et le cancer du col de l'utérus dans la population SSA. Un modèle à effet fixe a été utilisé pour calculer le rapport de cotes combiné (OR) et les intervalles de confiance à 95% (IC95%). RÉSULTATS: Un total de 699 cas de cancer du col utérin et 1008 témoins de huit études en ASS ont été inclus dans cette méta-analyse. Les femmes hébergeant l'allèle variant G du TP53 rs1042522 présentaient un risque accru de cancer du col de l'utérus chez les modèles génétiques alléliques (G vs C; OR = 1,30, IC95%: 1,12-1,50), homozygotes (GG vs CC; OR = 1,62, IC95%: 1,20-2,19) et récessifs (GG vs.CG + GG; OR = 1,74, IC95%: 1,34-2,25). Cependant, le modèle génétique dominant (CG + GG vs CC; OR = 1,20, IC95%: 0,96-1,48) n'était pas significativement associé au cancer du col utérin. CONCLUSIONS: Notre méta-analyse a révélé que l'hébergement de l'allèle variant G de TP53 rs1042522 est associé au risque de cancer du col de l'utérus dans la population SSA.


Assuntos
Proteína Supressora de Tumor p53/genética , Neoplasias do Colo do Útero/genética , África Subsaariana/epidemiologia , Alelos , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Razão de Chances , Polimorfismo de Nucleotídeo Único
10.
Pediatr Hematol Oncol ; 35(3): 196-202, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30239249

RESUMO

Wilms tumor (WT) has a survival rate above 90% in high income countries. Reported survival rates in sub-Saharan Africa are much lower and long-term outcome is not well known as follow-up is challenging. In Blantyre, Malawi, an adapted WT treatment guideline with preoperative chemotherapy, supportive care, and strategies to enable children and parents to complete treatment was introduced in 2006. Between 2006 and 2011, 73 children with a unilateral WT were treated. Follow-up, including home visits when needed, was done. Median follow-up time is 5 years (range 14-95 months). Two and five-year event free survivals are 46 and 42%. Causes of treatment failure are: 7% (5/73) abandonment of treatment, 15% (11/73) death during treatment and 30% (22/73) disease-related deaths (persistent disease and relapse). Long-term follow-up is challenging but necessary to be able to assess outcome and the true impact of interventions.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Renais/mortalidade , Recidiva Local de Neoplasia/mortalidade , Tumor de Wilms/mortalidade , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/patologia , Malaui , Masculino , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/patologia , Prognóstico , Taxa de Sobrevida , Tumor de Wilms/tratamento farmacológico , Tumor de Wilms/patologia
11.
Malawi Med J ; 30(3): 162-166, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30627350

RESUMO

Introduction: Limited data exists on histologically confirmed cancers and tuberculosis in rural Malawi, despite the high burden of both conditions. One of the main reasons for the limited data is the lack of access to pathology services for diagnosis. We reviewed histopathology results of patients in Neno District, one of the poorest rural districts in Malawi, from May 2011 to July 2017, with an emphasis on cancers and tuberculosis. Methods: This is a retrospective descriptive study reviewing pathology results of samples collected at Neno health facilities and processed at Kamiza Pathology Laboratory. Data was entered into Microsoft Excel and cleaned and analysed using Stata 14. Results: A total of 532 specimens were collected, of which 87% (465) were tissue biopsies (incision or core biopsies), and 13% (67) were cytology samples. Of all specimens, 7% (n=40) of the samples had non-diagnostic results. Among the results that were diagnostic (n=492), 37% (183) were malignancies, 33% (112) were infections and inflammatory conditions other than tuberculosis, 20% (97) were benign tumours, 7% (34) were tuberculosis, 4% (21) were pre-malignant lesions, 5% (23) were normal samples, and 4% (22) were other miscellaneous conditions. Among the malignancies (n=183), 62% (114) were from females and 38% (69) from males. Among females, almost half of the cancers were cervical (43%, n= 49), followed by Kaposi sarcoma (14%, n=16), skin cancers (9%, n=10), and breast cancer (8%, n=9). In males, Kaposi sarcoma was the most common cancer (35%, n=24), followed by skin cancers (17%, n=12). About 75% (n=137) of the cancers occurred in persons aged 15 to 60 years. Conclusion: Histopathology services at a rural hospital in Malawi provides useful diagnostic information on malignancies, tuberculosis and other diagnoses, and can inform management at the district level.


Assuntos
Biópsia , Doenças Transmissíveis/patologia , Neoplasias/patologia , Serviços de Saúde Rural , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/patologia , Doenças Transmissíveis/epidemiologia , Feminino , Humanos , Malaui/epidemiologia , Masculino , Pessoa de Meia-Idade , Neoplasias/epidemiologia , Estudos Retrospectivos , População Rural , Sarcoma de Kaposi/epidemiologia , Sarcoma de Kaposi/patologia , Neoplasias Cutâneas/epidemiologia , Neoplasias Cutâneas/patologia , Adulto Jovem
12.
J Infect Dis ; 216(5): 545-553, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28931222

RESUMO

Background: Human immunodeficiency virus (HIV) infection is a recognized risk factor for stroke among young populations, but the exact mechanisms are poorly understood. We studied the clinical, radiologic, and histologic features of HIV-related ischemic stroke to gain insight into the disease mechanisms. Methods: We conducted a prospective, in-depth analysis of adult ischemic stroke patients presenting to Queen Elizabeth Central Hospital, Blantyre, Malawi, in 2011. Results: We recruited 64 HIV-infected and 107 HIV-uninfected patients. Those with HIV were significantly younger (P < .001) and less likely to have established vascular risk factors. Patients with HIV were more likely to have large artery disease (21% vs 10%; P < .001). The commonest etiology was HIV-associated vasculopathy (24 [38%]), followed by opportunistic infections (16 [25%]). Sixteen of 64 (25%) had a stroke soon after starting antiretroviral therapy (ART), suggesting an immune reconstitution-like syndrome. In this group, CD4+ T-lymphocyte count was low, despite a significantly lower HIV viral load in those recently started on treatment (P < .001). Conclusions: HIV-associated vasculopathy and opportunistic infections are common causes of HIV-related ischemic stroke. Furthermore, subtypes of HIV-associated vasculopathy may manifest as a result of an immune reconstitution-like syndrome after starting ART. A better understanding of this mechanism may point toward new treatments.


Assuntos
Infecções por HIV/complicações , Acidente Vascular Cerebral/virologia , Vasculite/complicações , Adulto , Idoso , Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Contagem de Linfócito CD4 , Estudos de Casos e Controles , Feminino , HIV , Infecções por HIV/tratamento farmacológico , Humanos , Síndrome Inflamatória da Reconstituição Imune/etiologia , Síndrome Inflamatória da Reconstituição Imune/virologia , Malaui , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/etiologia , Vasculite/diagnóstico , Vasculite/virologia , Carga Viral
13.
BMC Cancer ; 17(1): 633, 2017 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-28877678

RESUMO

BACKGROUND: Extranodal NK/T-cell lymphoma (ENKTCL) reports from sub-Saharan Africa (SSA) are remarkably rare, despite early childhood acquisition and high prevalence of the causative infectious agent, Epstein-Barr virus (EBV), and frequent occurrence of other lymphoproliferative disorders causally associated with EBV. CASE PRESENTATIONS: At a national teaching hospital in Malawi, three patients of African descent were seen with ENKTCL between 2013 and 2014. Patients were aged between 29 and 60 years, two with craniofacial involvement and one with a primary abdominal tumor, and all were HIV-negative. All had systemic B symptoms, and two severely impaired performance status. On histologic review, morphology and immunophenotyping demonstrated classical ENKTCL features in all cases, including diffuse proliferations of intermediate-to-large atypical lymphocytes with high mitotic activity and extensive background necrosis, positivity for CD3 and CD56, and negativity for CD20. By in situ hybridization, all three tumors were positive for EBV-encoded RNA (EBER). Baseline plasma EBV DNA was also markedly elevated for all three patients. Due to radiotherapy and chemotherapy limitations, patients were treated with CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) with rapid disease progression. All three patients died from progressive lymphoma within 3 months of initial diagnosis. CONCLUSIONS: Our experience with these three patients in Malawi can highlight that ENKTCL does indeed occur in SSA, increase familiarity with ENKTCL among clinicians and pathologists throughout the region, and emphasize the need for better diagnosis and treatment for this neglected population.


Assuntos
Linfoma Extranodal de Células T-NK/diagnóstico , Linfoma Extranodal de Células T-NK/tratamento farmacológico , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores , Biópsia , Ciclofosfamida/uso terapêutico , DNA Viral , Doxorrubicina/uso terapêutico , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/virologia , Feminino , Herpesvirus Humano 4/genética , Humanos , Imunofenotipagem/métodos , Linfoma Extranodal de Células T-NK/etiologia , Linfoma Extranodal de Células T-NK/metabolismo , Malaui , Masculino , Pessoa de Meia-Idade , Prednisona/uso terapêutico , Resultado do Tratamento , Vincristina/uso terapêutico
14.
J Glob Oncol ; 3(3): 227-234, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28717764

RESUMO

PURPOSE: Cervical squamous cell carcinoma (SCC) continues to be a significant cause of cancer morbidity and is the third leading cause of cancer-related death in women worldwide. In sub-Saharan Africa, cervical cancer is not only the most common female cancer but also the leading cause of cancer-related deaths in women. Malawi, in particular, has the highest burden of cervical cancer. With the increasing use of human papillomavirus (HPV) vaccination, documenting the prevalent HPV types in those high-risk populations is necessary to both manage expectations of HPV vaccination and guide future vaccine development. MATERIALS AND METHODS: In this study, we performed HPV typing on 474 cervical SCC samples and analyzed the potential impact of HPV vaccination in this population. RESULTS: Ninety-seven percent of tumors were positive for at least one HPV type, and 54% harbored more than one HPV type. HPV 16 was the most common type (82%), followed by HPV 18 (34%), HPV 35 (24%), and HPV 31 (12%). A vaccine against HPV 16 and 18 would ideally prevent 53% of cervical SCC, and the nonavalent HPV vaccine (covering HPV 16, 18, 31, 33, 45, 52, and 58) would prevent 71% of cervical SCC in Malawi (assuming 100% vaccine efficacy). The main reason for a lack of coverage was high prevalence of HPV 35, which was also present as a single infection in a small subset of patients. CONCLUSION: Although any HPV vaccination in this population would likely prevent a significant proportion of cervical cancer, the nonavalent vaccine would provide better coverage. Furthermore, investigation of the role of HPV 35 in this population, including possible cross-protection with other HPV types, should be pursued.

15.
Am J Clin Pathol ; 146(4): 423-30, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27594430

RESUMO

OBJECTIVES: The incidence of lymphoproliferative disorders (LPDs) is increasing in sub-Saharan Africa (SSA) due to population growth, aging, and human immunodeficiency virus (HIV). Despite significant burden, resources for diagnosis and treatment of LPDs are limited, with little infrastructure to deliver modern pathology services. Diagnostic and therapeutic decisions are therefore frequently made without tissue confirmation, leading to high rates of misdiagnosis and inappropriate treatment. METHODS: We have established a laboratory in Malawi to support clinical and research efforts at a national teaching hospital. Consensus real-time diagnoses are rendered by local pathologists after weekly clinicopathologic teleconferences involving clinicians and pathologists from the United States and Malawi. Additional ancillary studies are then performed in the United States prior to final diagnosis. RESULTS: We report our first 2 years' experience and demonstrate high concordance between real-time diagnoses in Malawi and final diagnoses in the United States (5% major discordance rate for formalin-fixed, paraffin-embedded samples). In addition, we describe characteristics of pathologically confirmed LPDs in Malawi, highlighting differences by HIV status. CONCLUSIONS: Our multidisciplinary approach can be a model for strong pathology services that provide direct, real-time support to clinical care and research in SSA.


Assuntos
Transtornos Linfoproliferativos/diagnóstico , Telepatologia , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Transtornos Linfoproliferativos/patologia , Malaui , Masculino , Pessoa de Meia-Idade
16.
PLoS One ; 11(3): e0150445, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26934054

RESUMO

There are no prospective studies of aggressive non-Hodgkin lymphoma (NHL) treated with CHOP in sub-Saharan Africa. We enrolled adults with aggressive NHL in Malawi between June 2013 and May 2015. Chemotherapy and supportive care were standardized, and HIV+ patients received antiretroviral therapy (ART). Thirty-seven of 58 patients (64%) were HIV+. Median age was 47 years (IQR 39-56), and 35 (60%) were male. Thirty-five patients (60%) had stage III/IV, 43 (74%) B symptoms, and 28 (48%) performance status ≥ 2. B-cell NHL predominated among HIV+ patients, and all T-cell NHL occurred among HIV- individuals. Thirty-one HIV+ patients (84%) were on ART for a median 9.9 months (IQR 1.1-31.7) before NHL diagnosis, median CD4 was 121 cells/µL (IQR 61-244), and 43% had suppressed HIV RNA. HIV+ patients received a similar number of CHOP cycles compared to HIV- patients, but more frequently developed grade 3/4 neutropenia (84% vs 31%, p = 0.001), resulting in modestly lower cyclophosphamide and doxorubicin doses with longer intervals between cycles. Twelve-month overall survival (OS) was 45% (95% CI 31-57%). T-cell NHL (HR 3.90, p = 0.017), hemoglobin (HR 0.82 per g/dL, p = 0.017), albumin (HR 0.57 per g/dL, p = 0.019), and IPI (HR 2.02 per unit, p<0.001) were associated with mortality. HIV was not associated with mortality, and findings were similar among patients with diffuse large B-cell lymphoma. Twenty-three deaths were from NHL (12 HIV+, 11 HIV-), and 12 from CHOP (9 HIV+, 3 HIV-). CHOP can be safe, effective, and feasible for aggressive NHL in Malawi with and without HIV.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Antirreumáticos/uso terapêutico , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Linfoma não Hodgkin/complicações , Linfoma não Hodgkin/tratamento farmacológico , Adulto , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Feminino , Infecções por HIV/epidemiologia , Humanos , Linfoma não Hodgkin/epidemiologia , Linfoma não Hodgkin/patologia , Malaui/epidemiologia , Masculino , Pessoa de Meia-Idade , Prednisona/uso terapêutico , Análise de Sobrevida , Vincristina/uso terapêutico
17.
Blood Adv ; 1(1): 84-92, 2016 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-29296697

RESUMO

Diagnostics and supportive care for patients with non-Hodgkin lymphoma (NHL) in lower- and middle-income countries (LMICs) are lacking. We hypothesized that high-throughput transcription-based diagnostics could classify NHL specimens from Malawi amenable to targeted therapeutics. We established tissue microarrays and classified 328 cases diagnosed by hematoxylin and eosin as NHL at University of Malawi College of Medicine using immunohistochemistry (IHC) for conventional markers and therapeutic targets. A subset was analyzed using NanoString-based expression profiling with parsimonious transcriptional classifiers. Overall, 72% of lymphomas were high-grade B-cell tumors, subsets of which were enriched for expression of MYC, BCL2, and/or PD-L1. A 21-gene transcriptional classifier, previously validated in Western cohorts, divided 96% of diffuse large B-cell lymphomas (DLBCLs) with 100% of B-cell lymphomas, unclassifiable, into 1 cluster and 88% of Burkitt lymphomas into a separate cluster. Cell-of-origin categorization of 36 DLBCLs by NanoString lymphoma subtyping test (LST) revealed 69% concordance with IHC. All discordant cases were classified as germinal center B cell-like (GCB) by LST but non-GCB by IHC. In summary, utilization of advanced diagnostics facilitates objective assessment and segregation of biologically defined subsets of NHL from an LMIC without expert review, thereby establishing a basis for the implementation of effective and less toxic targeted agents.

18.
Artigo em Inglês | MEDLINE | ID: mdl-25191643

RESUMO

Pediatric cerebral malaria carries a high mortality rate in sub-Saharan Africa. We present our systematic analysis of the descriptive and quantitative histopathology of all organs sampled from a series of 103 autopsies performed between 1996 and 2010 in Blantyre, Malawi on pediatric cerebral malaria patients and control patients (without coma, or without malaria infection) who were clinically well characterized prior to death. We found brain swelling in all cerebral malaria patients and the majority of controls. The histopathology in patients with sequestration of parasites in the brain demonstrated two patterns: (a) the "classic" appearance (i.e., ring hemorrhages, dense sequestration, and extra-erythrocytic pigment) which was associated with evidence of systemic activation of coagulation and (b) the "sequestration only" appearance associated with shorter duration of illness and higher total burden of parasites in all organs including the spleen. Sequestration of parasites was most intense in the gastrointestinal tract in all parasitemic patients (those with cerebral malarial and those without).


Assuntos
Malária Cerebral/patologia , Autopsia , Encéfalo/patologia , Criança , Pré-Escolar , Glândulas Endócrinas/parasitologia , Glândulas Endócrinas/patologia , Eritrócitos/parasitologia , Eritrócitos/patologia , Trato Gastrointestinal/parasitologia , Trato Gastrointestinal/patologia , Granuloma/patologia , Hemorragia/patologia , Humanos , Lactente , Pulmão/parasitologia , Pulmão/patologia , Malária Cerebral/epidemiologia , Malária Cerebral/parasitologia , Malaui/epidemiologia , Miocárdio/patologia , Sistema Urogenital/parasitologia , Sistema Urogenital/patologia
19.
Pediatr Blood Cancer ; 61(12): 2180-4, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25213396

RESUMO

BACKGROUND: Wilms tumour postoperative chemotherapy is ideally stratified according to the pathologist's assessment of tumour stage and risk classification (tumour type). In sub-Saharan Africa results are often not available in time to influence therapy and in Malawi surgical staging has been used to stratify postoperative chemotherapy. Here we compare the results from surgical and both local pathology and central pathology review. PROCEDURE: Children diagnosed with a Wilms tumour in Blantyre, Malawi between 2007 and 2011 were included if they had a nephrectomy and the pathology slides were available. All tumour specimens were assessed in three different ways: the local surgeon documented the surgical stage of the tumour, and the risk classification and pathology stage were assessed both by the local pathologist and by a SIOP central review pathologist in Europe. RESULTS: Fifty patients had complete data available and were included in the analyses. Tumour risk classification differed between the local and central pathology review in only two patients (4%). Using central pathology review as the gold standard 60% of patients received the correct postoperative chemotherapy treatment based on surgical staging and 84% based on the local pathology stage and risk classification. CONCLUSION: Local pathology capacity building is needed to enable timely assessment and reporting.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/patologia , Nefrectomia , Tumor de Wilms/tratamento farmacológico , Tumor de Wilms/patologia , Criança , Pré-Escolar , Terapia Combinada , Dactinomicina/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Seguimentos , Humanos , Lactente , Neoplasias Renais/cirurgia , Malaui , Masculino , Estadiamento de Neoplasias , Cuidados Pós-Operatórios , Prognóstico , Vincristina/administração & dosagem , Tumor de Wilms/cirurgia
20.
Sci Rep ; 4: 3741, 2014 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-24434689

RESUMO

Endemic Burkitt lymphoma (eBL) has been linked to Plasmodium falciparum (Pf) malaria infection, but the contribution of infection with multiple Pf genotypes is uncertain. We studied 303 eBL (cases) and 274 non eBL-related cancers (controls) in Malawi using a sensitive and specific molecular-barcode array of 24 independently segregating Pf single nucleotide polymorphisms. Cases had a higher Pf malaria prevalence than controls (64.7% versus 45.3%; odds ratio [OR] 2.1, 95% confidence interval (CI): 1.5 to 3.1). Cases and controls were similar in terms of Pf density (4.9 versus 4.5 log copies, p = 0.28) and having ≥3 non-clonal calls (OR 2.7, 95% CI: 0.7-9.9, P = 0.14). However, cases were more likely to have a higher Pf genetic diversity score (153.9 versus 133.1, p = 0.036), which measures a combination of clonal and non-clonal calls, than controls. Further work is needed to evaluate the possible role of Pf genetic diversity in the pathogenesis of endemic BL.


Assuntos
Linfoma de Burkitt/epidemiologia , Linfoma de Burkitt/etiologia , Variação Genética , Malária Falciparum/complicações , Malária Falciparum/parasitologia , Plasmodium falciparum/genética , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , DNA de Protozoário , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Malária Falciparum/epidemiologia , Malaui/epidemiologia , Masculino , Razão de Chances , Polimorfismo de Nucleotídeo Único , Prevalência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA