6 results on '"Ambada G"'
Search Results
2. Immunoglobulin G (IgG) specific responses to recombinant Qβ displayed MSP3 and UB05 in plasma of asymptomatic Plasmodium falciparum -infected children living in two different agro-ecological settings of Cameroon.
- Author
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Ngu L, Fotso HO, Nyebe I, Tchadji JC, Ambada G, Ndah A, Atechi B, Lissom A, Atabonkeng PE, Chukwuma G, Efezeuh V, Gyu PC, Esimone C, Nguedia JCA, Akum EA, Okeke M, Titanji VPK, Mbacham W, Bopda-Waffo A, and Wapimewah GN
- Subjects
- Humans, Cameroon, Child, Preschool, Infant, Female, Malaria Vaccines administration & dosage, Malaria Vaccines immunology, Male, Rain, Recombinant Proteins immunology, Malaria, Falciparum immunology, Malaria, Falciparum epidemiology, Immunoglobulin G blood, Plasmodium falciparum immunology, Enzyme-Linked Immunosorbent Assay, Protozoan Proteins immunology, Antigens, Protozoan immunology, Antibodies, Protozoan blood
- Abstract
Introduction: in areas with intense perennial malaria transmission, limited data is available on the impact of environmental conditions especially rainfall on naturally acquired immunity against promising malaria vaccine candidates. For this reason, we have compared IgG antibody responses specific to Plasmodium spp. derived MSP3 and UB05 vaccine candidates, in plasma of children living in two areas of Cameroon differing in rainfall conditions., Methods: data about children less than 5 years old was collected during the years 2017 and 2018. Next malaria asymptomatic P. falciparum (Pf) infected children were selected following malaria test confirmation. MSP3 and UB05 specific IgG antibody responses were measured in participant´s plasma using enzyme-linked immunosorbent assay (ELISA)., Results: interestingly, IgG antibody responses specific to UB05 were significantly higher (p<0.0001) in Pf-negative children when compared to their asymptomatic Pf-infected counterparts living in monomodal rainfall areas. In contrast, a significantly higher (p<0.0001) IgG response to MSP3 was observed instead in asymptomatic Pf-infected children in the same population. In addition, IgG responses specific to UB05 remained significantly higher in bimodal when compared to monomodal rainfall areas irrespective of children´s Pf infection status (p<0.0055 for Pf-positive and p<0.0001 for negative children). On the contrary, IgG antibody responses specific to MSP3 were significantly higher in bimodal relative to monomodal rainfall areas (P<0.0001) just for Pf-negative children., Conclusion: thus IgG antibody responses specific to UBO5 are a better correlate of naturally acquired immunity against malaria in Pf-negative Cameroonian children especially in monomodal rainfall areas., Competing Interests: The authors declare no competing interests., (Copyright: Loveline Ngu et al.)
- Published
- 2024
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3. Characterization of HIV-1 Reservoirs in Children and Adolescents: A Systematic Review and Meta-Analysis Toward Pediatric HIV Cure.
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Ka'e AC, Santoro MM, Nanfack A, Ngoufack Jagni Semengue E, Yagai B, Nka AD, Ambada G, Mpouel ML, Sagnia B, Kenou L, Sanhanfo M, Togna Pabo WLR, Takou D, Chenwi CA, Sonela N, Sosso SM, Nkenfou C, Colizzi V, Halle-Ekane GE, Ndjolo A, Ceccherini-Silberstein F, Perno CF, Lewin S, Tiemessen CT, and Fokam J
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- Infant, Female, Child, Humans, Adolescent, Male, Cross-Sectional Studies, Viremia, DNA, Viral Load, HIV Infections drug therapy, HIV Infections epidemiology, HIV-1 genetics, HIV Seropositivity
- Abstract
Objective: To conduct a comprehensive, systematic review of the profile of HIV-1 reservoirs in children and adolescents with perinatally acquired HIV infection., Study Design: Randomized and nonrandomized trials, cohort studies, and cross-sectional studies on HIV reservoirs in pediatric populations, published between 2002 and 2022, were included. Archived-drug resistance mutations (ADRMs) and the size of reservoirs were evaluated. Subgroup analyses were performed to characterize further the data, and the meta-analysis was done through random effect models., Results: Overall, 49 studies from 17 countries worldwide were included, encompassing 2356 perinatally infected participants (48.83% females). There are limited data on the quantitative characterization of viral reservoirs in sub-Saharan Africa, with sensitive methodologies such as droplet digital polymerase chain reaction rarely employed. The overall prevalence of ADRMs was 37.80% (95% CI 13.89-65.17), with 48.79% (95% CI 0-100) in Africa, 42.08% (95% CI 6.68-82.71) in America, 23.88% (95% CI 14.34-34.90) in Asia, and 20.00% (95% CI 10.72-31.17) in Europe, without any difference between infants and adolescents (P = .656). Starting antiretroviral therapy (ART) before 2 months of age limited the levels of HIV-1 DNA (P = .054). Participants with long-suppressed viremia (>5 years) had lower levels of HIV-1 DNA (P = .027). Pre- and post-ART CD4 ≤29% and pre-ART viremia ≥5Log were all found associated with greater levels of HIV-1 DNA (P = .038, P = .047, and P = .041, respectively)., Conclusions: The pooled prevalence of ADRMs is high in perinatally infected pediatric population, with larger proviral reservoir size driven by delayed ART initiation, a shorter period of viral suppression, and immunovirological failures. Thus, strategies for pediatric HIV functional cure should target children and adolescents with very early ART initiation, immunocompetence, and long-term viral suppression., Competing Interests: Declaration of Competing Interest Funded by the University of the Witwatersrand (CTT), Johannesburg, South Africa, and European and Developing Countries Clinical Trials Partnership (EDCTP) Adolescents Viral Reservoirs study (#TMA2020CDF3228). The funder of the study had no role in study design, data collection, data analysis, data interpretation, or writing of the report. The authors have no conflicts of interest to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)
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- 2024
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4. Characterisation of HIV-1 reservoirs in paediatric populations: protocol for a systematic review and meta-analysis.
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Ka'e AC, Nanfack A, Santoro MM, Yagai B, Ambada G, Sagnia B, Nka AD, Ngoufack Jagni Semengue E, Pabo W, Takou D, Sonela N, Colizzi V, Perno CF, Ceccherini-Silberstein F, Lewin SR, Tiemessen CT, and Fokam J
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- Infant, Adolescent, Child, Humans, Adult, Cross-Sectional Studies, Leukocytes, Mononuclear, Systematic Reviews as Topic, Meta-Analysis as Topic, Anti-Retroviral Agents therapeutic use, DNA, HIV-1 genetics, HIV Infections drug therapy, HIV Infections epidemiology, HIV Infections complications, HIV Seropositivity complications
- Abstract
Introduction: The success of antiretroviral therapy (ART) has changed HIV from a deadly to a chronic infection, thus increasing the transitioning from infancy toward adulthood. However, the virostatic nature of antiretrovirals maintains viruses in sanctuaries, with reactivation potentials. Because current ARTs are very limited for children, the emergence of new HIV epidemics driven by HIV drug-resistance mutations is favoured. Our systematic review aims to estimate the global burden of archived drug-resistance mutations (ADRMs) and the size of reservoir (HIV-1 DNA load), and their associated factors in children and adolescents., Methods and Analysis: Papers from the PubMed/MEDLINE, Google Scholar, ScienceDirect, African Journals Online and Academic Medical Education Databases will be systematically identified using the keywords: "HIV-1 reservoirs", "viral reservoirs", "HIV-1 DNA", infants, adolescents, child and children, linked by the following Boolean operators: 'OR' and 'AND'. Randomised and non-randomised trials, cohort studies and cross-sectional studies published in French or English from January 2002 will be included, while case reports, letters, comments, reviews, systematic reviews and meta-analyses, and editorials will be excluded. All studies describing data on ADRMs, HIV-1 DNA load and/or immunological markers among children/adolescents will be eligible. A random-effects model will be used to calculate the pooled prevalence of ADRMs. Data will be reported according to type of viral reservoir (peripheral blood mononuclear cells, CD4 cells), geographical location (country/continent), ethnicity/race, age (infants vs adolescents), gender, HIV-1 clades, ART exposure (naïve vs treated, drug class, type of regimen, age at ART initiation and treatment duration), WHO clinical staging (I, II, III, IV), immune status (immune compromised vs immune competent) and virological response (viraemic vs non-viraemic). Multivariate logistic regression will be performed to determine predictors of HIV reservoir profile in paediatric populations. The primary outcome will be to assess the genotypical and quantitative profile of HIV reservoirs, while the secondary outcomes will be to identify factors associated with ADRMs and reservoir size in paediatric populations., Ethics and Dissemination: Ethical approval is not applicable for this study as it will be based on published data. Results will be disseminated via a peer-reviewed scientific journal and relevant conferences., Prospero Registration Number: CRD42022327625., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2023
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5. Human papillomavirus positivity and cervical lesions in relation to HIV infection: a comparative assessment in the Cameroonian female population.
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Sosso SM, Tchouaket MCT, Fokam J, Simo RK, Semengue ENJ, Sando Z, Torimiro J, Tiga A, Lobe EE, Ambada G, Nange A, Nka AD, Chenwi C, Abba A, Ka'e AC, Fainguem N, Zam MKN, Yagai B, Billong SC, Colizzi V, and Ndjolo A
- Abstract
Cervical lesions, induced by high-risk oncogenic human papillomavirus (HR-HPV), in the context of HIV remains a global health challenge. We determined the effect of HR-HPV on the development of cervical lesions in women with and without HIV infection. A cross-sectional analytical study was conducted among 257 women living in Cameroon. HIV serology, HR-HPV genotyping and cervico-vaginal smear (CVS) were performed for all participants; among those declared HIV positive, plasma HIV viral load and CD4 count were measured. Statistical analyses were performed using Graph Pad version 6.0; P#x003C;0.05 was considered statistically significant. The mean age of the participants in our study was 37±6.5 years. According to HIV serology, 184 (71.59%) were HIV-positive vs. 73 (28.40%) HIV-negative. Among the HIV-positive women, the median CD4 count was 438 [IQR: 317-597] cells/mm3 and the median viremia was #x003C;40 [IQR: #x003C;40-2318] copies/ml. After successful genotyping, the prevalence of HR-HPV was 36.32% (73/201), with a significantly higher proportion in HIV-infected individuals (41.98% (55/131) vs. 25.71% (18/70); P=0.02; OR=2.1). The overall rate of cervical lesions was 23.34% (60/257), with a non-significantly higher proportion in HIV-infected participants (25.00% (46/184) vs. 19.17% (14/73); P=0.31). Relevantly, the presence of HR-HPV was significantly associated with cervical lesions (P#x003C;0.0001; OR=5.07), with a higher odds of cervical lesion in HIV-positive individuals (P#x003C;0.0001 and OR=5.67) compared to HIV-negative individuals (P=0.03 and OR=3.83). Although oncogenic HPV appears to be an independent factor in the development of cervical lesions, this study reveals higher odds of cervical lesions among HIV/HPV co-infection than in HPV infection alone., (Copyright © 2023, the Author(s).)
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- 2023
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6. Inflammatory profile of vertically HIV-1 infected adolescents receiving ART in Cameroon: a contribution toward optimal pediatric HIV control strategies.
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Ka'e AC, Nanfack AJ, Ambada G, Santoro MM, Takou D, Semengue ENJ, Nka AD, Bala MLM, Endougou ON, Elong E, Beloumou G, Djupsa S, Gouissi DH, Fainguem N, Tchouaket MCT, Sosso SM, Kesseng D, Ndongo FA, Sonela N, Kamta ACL, Tchidjou HK, Ndomgue T, Ndiang STM, Nlend AEN, Nkenfou CN, Montesano C, Halle-Ekane GE, Cappelli G, Tiemessen CT, Colizzi V, Ceccherini-Silberstein F, Perno CF, and Fokam J
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- Pregnancy, Humans, Adolescent, Female, Child, Male, Tumor Necrosis Factor-alpha, Cameroon, Cross-Sectional Studies, Interleukin-4, Interleukin-6, Interleukin-12, Cytokines, Anti-Retroviral Agents, HIV Infections drug therapy, HIV-1, HIV Seropositivity
- Abstract
Antiretroviral therapy (ART) has improved the lifespan of people living with HIV. However, their immune system remains in a state of sustained activation/inflammation, which favors viral replication and depletion of helper T-cells with varying profiles according to ART-response. We herein sought to ascertain the inflammatory profile of adolescents living with perinatal HIV-1 infection (ALPHI) receiving ART in an African context. In this cross-sectional and comparative study among ART-experienced ALPHI in Yaoundé-Cameroon, HIV-1 RNA was measured by Abbott Real-time PCR; CD4 cells were enumerated using flow cytometry; serum cytokines were measured by ELISA; HIV-1 proviral DNA was genotyped by Sanger-sequencing; and archived drug resistance mutations (ADRMs) were interpreted using Stanford HIVdb.v9.0.1. Overall, 73 adolescents were enrolled (60 ALPHI and 13 HIV-1 negative peers) aged 15 (13-18) years; 60.00% were female. ART median duration was 92 (46-123) months; median viral load was 3.99 (3.17-4.66) RNA Log
10 (copies)/mL and median CD4 count was 326 (201-654) cells/mm3 . As compared to HIV-negative adolescents, TNFα was highly expressed among ALPHI (p<0.01). Following a virological response, inflammatory cytokines (IFNγ and IL-12), anti-inflammatory cytokines (IL-4 and IL-10) and inflammation-related cytokines (IL-6 and IL-1β) were highly expressed with viral suppression (VS) vs. virological failure (VF), while the chemokine CCL3 was highly expressed with VF (p<0.01). Regarding the immune response, the inflammatory cytokine TNFα was highly expressed in those that are immunocompetent (CD4≥500 cell/mm3 ) vs. immunocompromised (CD4<500 cell/mm3 ), p ≤ 0.01; while chemokine CCL2 was highly expressed in the immunocompromised (p<0.05). In the presence of ADRMs, IL-4 and CCL3 were highly expressed (p=0.027 and p=0.043 respectively). Among ART-experienced ALPHI in Cameroon, the TNFα cytokine was found to be an inflammatory marker of HIV infection; IFNγ, IL-1β, IL-6, and IL-12 are potential immunological markers of VS and targeting these cytokines in addition to antiretroviral drugs may improve management. Moreover, CCL3 and CCL2 are possible predictors of VF and/or being immunocompromised and could serve as surrogates of poor ART response., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Ka’e, Nanfack, Ambada, Santoro, Takou, Semengue, Nka, Bala, Endougou, Elong, Beloumou, Djupsa, Gouissi, Fainguem, Tchouaket, Sosso, Kesseng, Ndongo, Sonela, Kamta, Tchidjou, Ndomgue, Ndiang, Nlend, Nkenfou, Montesano, Halle-Ekane, Cappelli, Tiemessen, Colizzi, Ceccherini-Silberstein, Perno and Fokam.)- Published
- 2023
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