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Intermolecular interactions of protein-protein complexes play a principal role in the process of discovering new substances used in the diagnosis and treatment of many diseases. Among such complexes of proteins, we have to mention antibodies; they interact with specific antigens of two genera of single-stranded RNA viruses belonging to the family Filoviridae-Ebolavirus and Marburgvirus; both cause rare but fatal viral hemorrhagic fever in Africa, with pandemic potential. In this research, we conduct studies aimed at the design and evaluation of antibodies targeting the filovirus glycoprotein precursor GP-1,2 to develop potential targets for the pan-filovirus easy-to-use rapid diagnostic tests. The in silico research using the available 3D structure of the natural antibody-antigen complex was carried out to determine the stability of individual protein segments in the process of its formation and maintenance. The computed free binding energy of the complex and its decomposition for all amino acids allowed us to define the residues that play an essential role in the structure and indicated the spots where potential antibodies can be improved. Following that, the study involved targeting six epitopes of the filovirus GP1,2 with two polyclonal antibodies (pABs) and 14 monoclonal antibodies (mABs). The evaluation conducted using Enzyme Immunoassays tested 62 different sandwich combinations of monoclonal antibodies (mAbs), identifying 10 combinations that successfully captured the recombinant GP1,2 (rGP). Among these combinations, the sandwich option (3G2G12* - (rGP) - 2D8F11) exhibited the highest propensity for capturing the rGP antigen.
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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.
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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/genéticaRESUMO
Background: In January 2020, a previously unknown coronavirus strain was identified as the cause of a severe acute respiratory syndrome (SARS-CoV-2). The first viral whole-genome was sequenced using high-throughput sequencing from a sample collected in Wuhan, China. Whole-genome sequencing (WGS) is imperative in investigating disease outbreak transmission dynamics and guiding decision-making in public health. Methods: We retrieved archived SARS-CoV-2 samples at the Integrated Biorepository of H3Africa Uganda, Makerere University (IBRH3AU). These samples were collected previously from individuals diagnosed with coronavirus disease 2019 (COVID-19) using real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR). 30 samples with cycle thresholds (Cts) values <25 were selected for WGS using SARS-CoV-2 ARTIC protocol at Makerere University Molecular Diagnostics Laboratory. Results: 28 out of 30 (93.3%) samples generated analyzable genomic sequence reads. We detected SARS-CoV-2 and lineages A (22/28) and B (6/28) from the samples. We further show phylogenetic relatedness of these isolates alongside other 328 Uganda (lineage A = 222, lineage B = 106) SARS-CoV-2 genomes available in GISAID by April 22, 2021 and submitted by the Uganda Virus Research Institute. Conclusions: Our study demonstrated adoption and optimization of the low-cost ARTIC SARS-CoV-2 WGS protocol in a resource limited laboratory setting. This work has set a foundation to enable rapid expansion of SARS-CoV-2 WGS in Uganda as part of the Presidential Scientific Initiative on Epidemics (PRESIDE) CoV-bank project and IBRH3AU.
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COVID-19 , SARS-CoV-2 , Humanos , Filogenia , Uganda/epidemiologia , Sequenciamento Completo do GenomaRESUMO
Endemic Burkitt lymphoma (eBL) is an aggressive childhood B-cell lymphoma associated with Plasmodium falciparum (Pf) malaria and Epstein-Barr virus (EBV) infections. Variation in the Human Leukocyte Antigen (HLA) system is suspected to play a role, but assessments using less accurate serology-based HLA typing techniques in small studies yielded conflicting results. We studied 200 eBL cases and 400 controls aged 0-15 years enrolled in northern Uganda and typed by accurate high-resolution HLA sequencing methods. HLA results were analyzed at one- or two-field resolution. Odds ratios and 95% confidence intervals (aOR, 95% CI) for eBL risk associated with common HLA alleles versus alleles that were rare (<1%) or differed by <2% between the cases and controls as the reference category, were estimated using multiple logistic regression adjusting for age, sex, microgeography, region, malaria positivity and treatment history, and genetic variants associated with eBL. Compared to the controls, eBL cases had a lower frequency of HLA-A*02 (aOR = 0·59, 95% CI 0·38-0·91), HLA-B*41 (aOR = 0·36, 95% CI 0·13-1·00), and HLA-B*58 alleles (aOR = 0·59, 95% CI 0·36-0·97). eBL cases had a lower frequency of HLA-DPB1 homozygosity (aOR = 0·57, 95% CI 0·40-0·82) but a higher frequency of HLA-DQA1 homozygosity (aOR = 2·19, 95% CI 1·42-3·37). Our results suggest that variation in HLA may be associated with eBL risk.
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Linfoma de Burkitt/sangue , Antígenos HLA/metabolismo , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Fatores de Risco , UgandaRESUMO
BACKGROUND: Ebolavirus and Marburgvirus are genera of the virus family Filoviridae. Filoviruses cause rare but fatal viral hemorrhagic fevers (VHFs) in remote villages of equatorial Africa with potential for regional and international spread. Point-of-care (POC) rapid diagnostic tests (RDTs) are critical for early epidemic detection, reponse and control. There are 2 RDTs for Zaire ebolavirus (EBOV), but not other Ebolavirus spp. or Marburg marburgvirus (MARV). We validate 3 conserved B cell epitopes of filovirus glycoprotein (GP) using ebola virus diseases (EVD) survivor samples, towards devising pan-filovirus RDTs. METHODS: In-silico Immuno-informatics:- (a) multiple and basic local alignments of amino-acid sequences of filovirus (4 Ebolavirus spp. & MARV) Gp1, 2 and epitope prediction and conservation analyses within context of ClusterW, BLAST-P and the immune epitope database analysis resource (IEDB-AR); alongside (b) in-vitro enzyme immuno-assays (EIAs) for SUDV Gp1, 2 antigen and host-specific antibodies (IgM and IgG) among 94 gamma irradiated EVD survivor serum and 9 negative controls. RESULTS: Linear B cell epitopes were present across the entire length of all Gp1, 2, most lying in the region between amino acids positioned 350 and 500. Three seperate epitopes 97/80_GAFFLYDRLAST, 39_YEAGEWAENCY and 500_CGLRQLANETTQALQLFLRATTELR (designated UG-Filo-Peptide- 1, 2 and 3 respectively) were conserved within all studied filovirus species Gp1, 2. Gp1, 2 host specific IgM levels were comparably low (av. ODs < 0.04 [95% CI: 0.02837 to 0.04033]) among the 9 negative controls and 57 survivor samples analyzed. Host specific IgG levels, on the other hand, were elevated (av. ODs > 1.7525 [95% CI: 0.3010 to 3.1352]) among the 92 survivor samples relative to the 9 negative controls (av. ODs < 0.2.321 [95% CI: -0.7596 to 0.5372]). Filovirus Gp1, 2 antigen was not detected [av. ODs < 0.20] within EVD survivor serum relative to recombinant protein positive controls [av. ODs = 0.50]. CONCLUSIONS: These conserved B cell epitopes of filovirus Gp1, 2 and their derivative antibodies are promising for research and development of RDTs for EVD, with potential for extension to detect MVD.
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Ebolavirus/imunologia , Epitopos de Linfócito B/imunologia , Glicoproteínas/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/imunologia , Sequência Conservada , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/virologia , Humanos , Imunoglobulina G , Imunoglobulina M , Doença do Vírus de Marburg/diagnóstico , Doença do Vírus de Marburg/virologia , Marburgvirus/imunologia , Kit de Reagentes para Diagnóstico , Proteínas Virais/genética , Proteínas Virais/imunologiaRESUMO
BACKGROUND: Plasmodium falciparum (Pf) malaria infection is suspected to cause endemic Burkitt Lymphoma (eBL), but the evidence remains unsettled. An inverse relationship between sickle cell trait (SCT) and eBL, which supports that between malaria and eBL, has been reported before, but in small studies with low power. We investigated this hypothesis in children in a population-based study in northern Uganda using Mendelian Randomization. METHODS: Malaria-related polymorphisms (SCT, IL10, IL1A, CD36, SEMA3C, and IFNAR1) were genotyped in 202 eBL cases and 624 controls enrolled during 2010-2015. We modeled associations between genotypes and eBL or malaria using logistic regression. FINDINGS: SCT was associated with decreased risk of eBL (adjusted odds ratio [OR] 0·37, 95% CI 0·21-0·66; p=0·0003). Decreased risk of eBL was associated with IL10 rs1800896-CT (OR 0·73, 95% CI 0·50-1·07) and -CC genotypes (OR 0·53, 95% CI 0·29-0·95, ptrend=0·019); IL1A rs2856838-AG (OR 0·56, 95% CI 0·39-0·81) and -AA genotype (OR 0·50, 95% CI 0·28-1·01, ptrend=0·0016); and SEMA3C rs4461841-CT or -CC genotypes (OR 0·57, 95% CI 0·35-0·93, p=0·0193). SCT and IL10 rs1800896, IL1A rs2856838, but not SEMA3C rs4461841, polymorphisms were associated with decreased risk of malaria in the controls. INTERPRETATION: Our results support a causal effect of malaria infection on eBL.
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Linfoma de Burkitt/genética , Predisposição Genética para Doença , Malária Falciparum/genética , Análise da Randomização Mendeliana , Adolescente , Linfoma de Burkitt/complicações , Linfoma de Burkitt/epidemiologia , Linfoma de Burkitt/parasitologia , Criança , Pré-Escolar , Feminino , Estudos de Associação Genética , Genótipo , Humanos , Lactente , Recém-Nascido , Malária Falciparum/complicações , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Plasmodium falciparum/patogenicidade , Uganda/epidemiologiaRESUMO
BACKGROUND: Clinical and laboratory diagnosis of Active Tuberculosis (ATB) and latent Mycobacterium Tuberculosis (M. tuberculosis) infections (LTBI) among people living with HIV/AIDS (PLWHA) presents formidable challenges. In the past, WHO issued an advisory against the use of existing TB sero-diagnostics. Emerging evidence, however, points to a precision of TB sero-diagnostics based on secretory rather than structural M. tuberculosis antigens. We hypothesized that secretory levels of M. tuberculosis thymidylate kinase (TMKmt) can Designate ATBI from LTBI and no TB (NTB). Here, we report in-house validation studies of levels of TMKmt antigen (Ag) and host specific TMKmt antibody (Ab) amongst HIV +ve and HIV -ve participants. METHODS AND RESULTS: Direct TMKmt Ag and host specific IgG Ab detection EIAs were conducted on broadly consented, stored serum (N=281[Ag] vs. 214 [Ab] respective) samples stratified as either HIV +ve or HIV-ve ATB relative to LTBI and No TB. On one hand, UG-peptide 1 and its PAb-based EIAs accurately diagnosed ATB relative to LTBI and NTB among HIV +ve subjects {irrespectively: (a) Ag detection ATB=OD>0.490; 95% CI: 0.7446 to 0.8715 vs. LTBI=OD<0.490; 95% CI 0.4325 to 0.4829 vs. NTB=OD<0.26; 95% CI 0.1675 to 0.2567 and (b) TMKmt specific IgG detection ATB=OD>1.00; 95% CI 1.170 to 1.528 [HIV +ve] and 2.044 to 2.978 [HIV -ve] respectively vs. LTBI=OD<1.00; 95% CI 0.2690 to 0.6396 vs. NTB=OD<; 95% CI 0.1527 to 0.8751}. HIV -ve ATB presented with Ag levels greater than NTB and less than LTBI (i.e. ATB -ve=<0.490 ODs>0.26), but displayed better ant-TMKmt IgG responses (OD>2.00; 95% CI 2.044 to 2.978) relative to HIV +ve ATB (OD<1.600; 95% CI 1.170 to 1.528); suggesting a better control of M. tuberculosis-septicemia. On the other hand, UG-peptide 2 and its PAb-based EIAs did not demonstrate ATB diagnostic potential regardless of HIV sero-status, except towards designating NTB. CONCLUSIONS: TMKmt Ab and Ag detecting EIAs based on UG-peptide 1 and its derivative PAb can accurately demarcate ATB from LTBI and NTB among HIV +ve subjects.
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BACKGROUND: Laboratory diagnosis of Tuberculosis (TB) is traditionally based on microscopy and or culture. Microscopy is however, only sensitive to a specified degree of bacillary load not present in HIV co-infected persons. Traditional cultures of Mycobacterium tuberculosis (M. tb), on the other hand, take weeks to read-thereby delaying the critical decision whether or not, to treat. Although nucleic acids amplification tests (NAATS) applied directly on sputum or cultures can increase the sensitivity for TB diagnosis among those with HIV co-infection as well as reduce time-lines for positive culture detection, they do not replace the need for smear microscopy and culture. We have previously proposed the M. tb DNA-synthetic enzyme thymidylate kinase (aka TMKmt) as an organism-specific growth and proliferation biomarker to reduce time-lines for detection of positive TB cultures. In this study, we explored the secretory levels of TMKmt in M. tb cultures and sputum, towards improving the overall laboratory diagnosis of TB. METHODS AND RESULTS: Modelling of TMKmt secretion in vitro was done by cloning, expressing and SDS-PAGE/MALDI-TOF detection of purified recombinant TMKmt in E. coli. TMKmt expression profiling in M. tb was done by qRT-PCR assay of related messenger ribonucleic acids (mRNA) and TMKmt antigen detection by Enzyme linked Immuno-absorbent Assay (EIA) among cultures of a pathogenic wild-type Ugandan strain (genotype 1) alongside the H37Rv laboratory strain. Owing to the high-load of pathogen in-culture, direct EIA on limiting dilutions of sputum were done to examine for assay sensitivity. A rise in TMKmt antigen levels was observed at 3 h post-innoculation among in vitro cultures of E. coli. The 1st of several cyclic spikes in TMKmt mRNA and antigen levels were detected at 2.5 h among in vitro cultures of the pathogenic wild-type Ugandan isolate alongside the laboratory M. tb strain. TMKmt antigen was detected up to between 1 × 10-4-1 × 10-5 (containing 10 and 1 CFUs/ml) dilutions of a microscopically designated 1+ (est. Acid Fast Bacillary load of 1 × 105) patient sample. CONCLUSIONS: Detection of TMKmt expressed mRNA and Ag offers us opportune for instant diagnosis of M. tb in sputum, and reduction of timelines for positive pathogen detection in cultures to within 3 h.
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Antígenos de Bactérias/análise , Técnicas Imunoenzimáticas , Mycobacterium tuberculosis/isolamento & purificação , Núcleosídeo-Fosfato Quinase/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Tuberculose Pulmonar/diagnóstico , Adulto , Anticorpos/química , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Coinfecção , Feminino , Expressão Gênica , HIV/fisiologia , Infecções por HIV/diagnóstico , Infecções por HIV/virologia , Humanos , Limite de Detecção , Masculino , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/imunologia , Núcleosídeo-Fosfato Quinase/genética , Núcleosídeo-Fosfato Quinase/imunologia , Proteínas Recombinantes/análise , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Escarro/microbiologia , Fatores de Tempo , Tuberculose Pulmonar/microbiologiaRESUMO
BACKGROUND: Previous studies were conflicting regarding the associations between HPV vaccination, cervical cancer risk perceptions, high-risk sexual behaviors and STIs. This study compared the HPV-vaccinated and non-vaccinated young women in Uganda regarding cervical cancer risk perceptions, high-risk sexual behaviors, syphilis and HIV infections 5 years after vaccine implementation. METHODS: This was a population-based comparative cross-sectional survey conducted in Uganda. The 438 participants were sexually active young women aged 15-24 years and mean age was 18.6 (SD 1.4). The majority (53.0%) were HPV-vaccinated in 2008 without assessment of sexual activity prior to HPV vaccination. Upon verbal assessment of sexual activity at the time of follow-up, data were collected using a questionnaire and laboratory testing of blood samples for syphilis and HIV infections. RESULTS: There were no significant differences between the HPV-vaccinated and non-vaccinated groups regarding the prevalence of high-risk sexual behaviors, syphilis and HIV infections. Cervical cancer risk perceptions and age at sexual debut were nonetheless significantly lower among the vaccinated group compared to their non-vaccinated counterparts. However, HPV vaccination was not significantly associated to cervical cancer risk perceptions and early age at sexual debut in multivariate logistic regression analysis. CONCLUSIONS: We found no associations between HPV vaccination, cervical cancer risk perceptions, high-risk sexual behaviors, syphilis and HIV infections among young women in Uganda 5 years after vaccine implementation. Young girls in the study population were found to be sexually active at a young age, affirming the importance of targeting girls of younger age for HPV vaccination.
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Assunção de Riscos , Comportamento Sexual/psicologia , Infecções Sexualmente Transmissíveis/psicologia , Neoplasias do Colo do Útero/psicologia , Vacinação/psicologia , Adolescente , Fatores Etários , Estudos Transversais , Feminino , Seguimentos , Infecções por HIV/epidemiologia , Infecções por HIV/psicologia , Humanos , Modelos Logísticos , Análise Multivariada , Infecções por Papillomavirus/prevenção & controle , Infecções por Papillomavirus/psicologia , Vacinas contra Papillomavirus/uso terapêutico , Fatores de Risco , Comportamento Sexual/estatística & dados numéricos , Infecções Sexualmente Transmissíveis/epidemiologia , Uganda/epidemiologia , Neoplasias do Colo do Útero/prevenção & controle , Neoplasias do Colo do Útero/virologia , Adulto JovemRESUMO
BACKGROUND: Falciparum malaria is an important risk factor for African Burkitt lymphoma (BL), but few studies have evaluated malaria patterns in healthy BL-age children in populations where both diseases are endemic. To obtain accurate current data, patterns of asymptomatic malaria were investigated in northern Uganda, where BL is endemic. METHODS: Between 2011 and 2015, 1150 apparently healthy children under 15 years old were sampled from 100 villages in northern Uganda using a stratified, multi-stage, cluster survey design. Falciparum malaria prevalence (pfPR) was assessed by questionnaire, rapid diagnostic test (RDT) and thick film microscopy (TFM). Weighted pfPR and unadjusted and adjusted associations of prevalence with covariates were calculated using logistic models and survey methods. RESULTS: Based on 1143 children successfully tested, weighted pfPR was 54.8% by RDT and 43.4% by TFM. RDT sensitivity and specificity were 97.5 and 77.8%, respectively, as compared to TFM, because RDT detect malaria antigens, which persist in peripheral blood after clinical malaria, thus results based on RDT are reported. Weighted pfPR increased from 40% in children aged under 2 years to 61.8% in children aged 6-8 years (odds ratio 2.42, 95% confidence interval (CI) 1.26-4.65), then fell slightly to 49% in those aged 12-15 years. Geometric mean parasite density was 1805.5 parasites/µL (95% CI 1344.6-2424.3) among TFM-positive participants, and it was higher in children aged <5 years at 5092.9/µL (95% CI 2892.7-8966.8) and lower in those aged ≥10 years at 983.8/µL (95% CI 472.7-2047.4; P = 0.001). Weighted pfPR was lower in children residing in sub-regions employing indoor residual spraying (IRS) than in those residing in non-IRS sub-regions (32.8 versus 65.7%; OR 0.26, 95% CI 0.14, 0.46). However, pfPR varied both within IRS (3.2-55.3%) and non-IRS sub-regions (29.8-75.8%; Pheterogeneity <0.001). pfPR was inversely correlated with a child's mother's income (P = 0.011) and positively correlated with being enrolled in the wet season (P = 0.076), but sex was irrelevant. CONCLUSIONS: The study observed high but geographically and demographically heterogenous patterns of asymptomatic malaria prevalence among children living in northern Uganda. These results provide important baseline data that will enable precise evaluation of associations between malaria and BL.
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Linfoma de Burkitt/epidemiologia , Doenças Endêmicas , Malária Falciparum/epidemiologia , Adolescente , Criança , Pré-Escolar , Testes Diagnósticos de Rotina , Feminino , Humanos , Lactente , Recém-Nascido , Malária Falciparum/parasitologia , Masculino , Plasmodium falciparum/isolamento & purificação , Prevalência , Sensibilidade e Especificidade , Uganda/epidemiologiaRESUMO
The objective of this study was to determine the prevalence and some predictors for vaccine and non-vaccine types of HPV infections among bivalent HPV vaccinated and non-vaccinated young women in Uganda. This was a comparative cross sectional study 5.5 years after a bivalent HPV 16/18 vaccination (Cervarix®, GlaxoSmithKline, Belgium) pilot project in western Uganda. Cervical swabs were collected between July 2014-August 2014 and analyzed with a HPV genotyping test, CLART® HPV2 assay (Genomica, Madrid Spain) which is based on PCR followed by microarray for determination of genotype. Blood samples were also tested for HIV and syphilis infections as well as CD4 and CD8 lymphocyte levels. The age range of the participants was 15-24 years and mean age was 18.6(SD 1.4). Vaccine-type HPV-16/18 strains were significantly less prevalent among vaccinated women compared to non-vaccinated women (0.5% vs 5.6%, p 0.006, OR 95% CI 0.08(0.01-0.64). At type-specific level, significant difference was observed for HPV16 only. Other STIs (HIV/syphilis) were important risk factors for HPV infections including both vaccine types and non-vaccine types. In addition, for non-vaccine HPV types, living in an urban area, having a low BMI, low CD4 count and having had a high number of life time sexual partners were also significant risk factors. Our data concurs with the existing literature from other parts of the world regarding the effectiveness of bivalent HPV-16/18 vaccine in reducing the prevalence of HPV infections particularly vaccine HPV- 16/18 strains among vaccinated women. This study reinforces the recommendation to vaccinate young girls before sexual debut and integrate other STI particularly HIV and syphilis interventions into HPV vaccination packages.
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Papillomavirus Humano 16/efeitos dos fármacos , Papillomavirus Humano 18/efeitos dos fármacos , Vacinação em Massa , Infecções por Papillomavirus/epidemiologia , Infecções por Papillomavirus/prevenção & controle , Vacinas contra Papillomavirus/administração & dosagem , Adolescente , Coinfecção , Estudos Transversais , Feminino , Genótipo , Infecções por HIV/epidemiologia , Infecções por HIV/microbiologia , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/imunologia , Papillomavirus Humano 18/genética , Papillomavirus Humano 18/imunologia , Humanos , Programas de Imunização/organização & administração , Infecções por Papillomavirus/imunologia , Projetos Piloto , Prevalência , Sífilis/epidemiologia , Sífilis/microbiologia , Uganda/epidemiologia , Adulto JovemRESUMO
BACKGROUND: Mycobacterium tuberculosis (Mtb) is reported to infect about a third of the world's population but only 10% are thought to develop active tuberculosis (TB) disease. Host immunity regulated by human leukocyte antigens (HLA) is an important determinant of the outcome of the disease. Here we investigate HLA class II gene polymorphisms in susceptibility to TB, and whether particular HLA class II alleles were associated with TB in Uganda. METHODS: HIV negative patients with pulmonary TB (n = 43) and genetically related healthy household controls (n = 42) were typed for their HLA II class alleles using polymerase chain reaction sequence specific primer amplification. RESULTS: The HLA-DQB1*03:03 allele was significantly less frequent in patients compared to healthy controls (10% in controls versus 0% in patients, p = 0.003). After correction for multiple comparisons the difference remained significant (p = 0.018). CONCLUSIONS: Our results suggest that the HLA-DQB1*03:03 allele may be associated with resistance to TB.
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Cadeias beta de HLA-DQ/genética , Antígenos HLA-DR/genética , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/genética , Adolescente , Adulto , Idoso , Alelos , Feminino , Predisposição Genética para Doença , Antígenos HLA-DR/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo Genético , Tuberculose Pulmonar/imunologia , Uganda , Adulto JovemRESUMO
BACKGROUND: Cataracts contribute 12% of visual loss among HIV-infected adults in Uganda. Immuno-pathogenesis of cataracts may differ among HIV-infected individuals; thus the need for innovative therapeutic interventions among HIV-infected adults. METHODS: In a laboratory based case-control study, nested in a clinical/surgical community outreach camp, 50 adults with cataracts eligible for surgery were selected consecutively. HIV testing was done for individuals with unknown HIV sero-status. Peripheral Blood Mononuclear Cells (PBMC) were collected from all HIV-positive-adults-with-cataracts (cases) and HIV-negative-adults-with-cataracts (comparative group) and age-matched HIV-negative and HIV-positive-adults-without-cataracts (comparative group). Treg were measured as CD3+CD4+FoxP3+CD25+(Bright) and immune activation as CD3+CD4+CD38+HALDR+ using a Facs Canto II flowcytometer. Mann Whitney test was used to compare expression among the four groups. RESULTS: Of 50 adults operated for cataracts, 24 (48%) were female, 25 (50%) were HIV-positive. HIV-positive-individuals had cataracts earlier [median; Inter-quartile Range (IQR); 49 (44-53) years] than HIV-negative [70 (IQR 59-75) years]; p=0.0005. Treg were lower among individuals with cataracts irrespective of HIV status; p=0.001; but comparable among younger HIV-positive and elderly HIV-negative with cataracts; p=0.301. Immune activation levels were comparable among HIV-positive and HIV-negative individuals with cataracts. However, HIV-positive-individuals with cataracts expressed higher levels of immune activation than HIV-positive-individuals without cataracts; p=0.012 and HIV-negative-individuals-with-cataracts expressed higher levels of immune activation that HIV-negative-without-cataracts; p<0.0001. CONCLUSION: CD4 T-cell activation and reduced regulatory T-cell populations were associated with cataracts among adults aging with HIV. We recommend studies on clinical relevance of immune modulation in the prevention of early development of cataracts among adults aging with HIV in Africa.
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Linfócitos T CD4-Positivos/imunologia , Catarata/etiologia , Infecções por HIV/complicações , Infecções por HIV/imunologia , Ativação Linfocitária/imunologia , Linfócitos T Reguladores/imunologia , Adulto , Idoso , Antígenos de Superfície/imunologia , Antígenos de Superfície/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Imunofenotipagem , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Linfócitos T Reguladores/metabolismo , UgandaRESUMO
BACKGROUND: Drug resistance among tuberculosis patients in sub-Saharan Africa is increasing, possibly due to association with HIV infection. We studied drug resistance and HIV infection in a representative sample of 533 smear-positive tuberculosis patients diagnosed in Kampala, Uganda. METHODS/PRINCIPAL FINDINGS: Among 473 new patients, multidrug resistance was found in 5 (1.1%, 95% CI 0.3-2.5) and resistance to any drug in 57 (12.1%, 9.3-15.3). Among 60 previously treated patients this was 7 (11.7%, 4.8-22.6) and 17 (28.3%; 17.5-41.4), respectively. Of 517 patients with HIV results, 165 (31.9%, 27.9-36.1) tested positive. Neither multidrug (adjusted odds ratio (OR(adj)) 0.7; 95% CI 0.19-2.6) nor any resistance (OR(adj) 0.7; 0.43-1.3) was associated with HIV status. Primary resistance to any drug was more common among patients who had worked in health care (OR(adj) 3.5; 1.0-12.0). CONCLUSION/SIGNIFICANCE: Anti-tuberculosis drug resistance rates in Kampala are low and not associated with HIV infection, but may be associated with exposure during health care.