Browsing by Author "Kwarteng, Alexander"
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- ItemBlood collection tubes impact expression of activated CD4+ and CD8+ T cells in human whole blood assay(Scientific African, 2023) Kwarteng, Alexander; Osei-Poku, Priscilla; Antwi-Berko, Daniel; Sylverken, Augustina Angelina; Larbi, Amma; Nsiah, Kwabena; 0000-0002-0893-2908; 0000-0002-9187-2503; 0000-0001-8994-1349; 0000-0002-7691-914X; 0000-0002-3814-6924; 0000-0001-8500-0963Background T-lymphocyte subsets CD4 and CD8 play important role in host immune responses. However, little attention has been given to the impact of time lapse and the various anticoagulant blood collection tubes on the expression frequency and activation status of CD4+ and CD8+ T cells. To this end, we explore the impact of time (t<1 h and t=4 h) and collection tubes (EDTA and heparin) on the expression frequency and activation status of CD4+ and CD8+ T cells among healthy Ghanaian individuals. Methods A cohort of healthy individuals (n=9) is recruited, and blood samples obtained in Ghana for the frequency of CD4+and CD8+ T cells at various time points (<1 h and 4 h). The proportions of activation of these immune markers were profiled using immunophenotyping. Results Significant statistical differences in the activation frequency of CD69 expressing CD4+T cells (t < 1 h and t=4 h; p=0.02) and CD69 expressing CD8+ T cells from EDTA tubes at times (t < 1 h and t=4 h; p=0.05) was observed. No significant difference were observed with CD69 expressing cells in Heparin tubes. Notably, CD8+ T cell activation frequency was observed to be consistently higher than that of CD4+ T cell at the various study time points and in the collection tubes used. No marked alterations were observed witth the proportion of CD4+ and CD8+ T cells in the samples collected at the time points; <1 h and at 4 h. Conclusion The study shows that activation of CD4+ and CD8+ T cells in EDTA tubes differed significantly between both time points (t <1 h and t=4 h) but not in the heparin collection tubes. Therefore, it is important to take into account the elapsed time and the type of blood collection tubes when performing phenotypic characterization of activated immune markers.
- ItemBurden of respiratory viral infections among inmates of a Ghanaian prison(Research Gate Publication, 2019-09-08) Sylverken, Augustina Angelina; El-Duah, Philip; Owusu, Michael; Yeboah, Richmond; Kwarteng, Alexander; Ofori, Linda; Gorman, Richmond; Obiri-Danso, Kwasi; Owusu-Dabo, Ellis; 0000-0002-7691-914X; 0000-0003-1671-0755; 0000-0003-1671-0755; 0000-0002-2765-6179; 0000-0002-0893-2908; 0000-0002-6831-3375; 0000-0002-5497-1684; 0000-0003-4232-4292Respiratory viral infections are important causes of morbidity and mortality worldwide. Information on circulating respiratory viruses among prisoners is lacking, although this is of public health importance and knowledge would assist in putting in place preventive measures to forestall disease outbreaks. The aim of this study therefore was to get the footprint of such diseases that have epidemic potential to be described and quantified for control. Prisoners on remand numbering 203 in a prison in Kumasi, the Ashanti Regional capital, were interviewed using prevalidated questionnaire, nasopharyngeal samples taken and screened by real-time PCR for common respiratory viruses in February, 2018. Of the total number of 203 participants enrolled, majority were males (n = 198, 97.54%). The modal age unsurprisingly was in the active working class of 18 to 35 years (n = 155, 76.36%) with 48 (23.65%) of participants older than 35 years. Inmates reported nasal congestion (n = 83, 40.89%), cough with or without pharyngitis (n =108, 53.20%) and fever (n = 74, 39.48%). Viruses detected in throat samples were Infl uenza A (n = 1, 0.49%) and Rhinovirus (n = 8, 3.94%). There was no statistically significant association between respiratory virus positivity and age (p = 0.118), gender (p > 0.900), duration of incarceration (p = 0.239) and reported symptoms (p = 0.724). The prison population may have a lower prevalence of respiratory viruses circulating in them. This may be dominated by those with high antigenic diversity.
- ItemElevated adaptive immune responses are associated with latent infections of wuchereria bancrofti(PLOS, 2012-04) Arndts, Kathrin; Deininger, Susanne; Specht, Sabine; Klarmann, Ute; Mand, Sabine; Adjobimey, Tomabu; Debrah, Alexander Y.; Batsa, Linda; Kwarteng, Alexander; Epp, Christian; Taylor, Mark; Adjei, Ohene; Layland, Laura E.; Hoerauf, AchimIn order to guarantee the fulfillment of their complex lifecycle, adult filarial nematodes release millions of microfilariae (MF), which are taken up by mosquito vectors. The current strategy to eliminate lymphatic filariasis as a public health problem focuses upon interrupting this transmission through annual mass drug administration (MDA). It remains unclear however, how many rounds of MDA are required to achieve low enough levels of MF to cease transmission. Interestingly, with the development of further diagnostic tools a relatively neglected cohort of asymptomatic (non-lymphedema) amicrofilaremic (latent) individuals has become apparent. Indeed, epidemiological studies have suggested that there are equal numbers of patent (MF+) and latent individuals. Since the latter represent a roadblock for transmission, we studied differences in immune responses of infected asymptomatic male individuals (n = 159) presenting either patent (n = 92 MF+) or latent (n = 67 MF2) manifestations of Wuchereria bancrofti. These individuals were selected on the basis of MF, circulating filarial antigen in plasma and detectable worm nests. Immunological profiles of either Th1/Th17, Th2, regulatory or innate responses were determined after stimulation of freshly isolated PBMCs with either filarial-specific extract or bystander stimuli. In addition, levels of total and filarial-specific antibodies, both IgG subclasses and IgE, were ascertained from plasma. Results from these individuals were compared with those from 22 healthy volunteers from the same endemic area. Interestingly, we observed that in contrast to MF+ patients, latent infected individuals had lower numbers of worm nests and increased adaptive immune responses including antigen-specific IL-5. These data highlight the immunosuppressive status of MF+ individuals, regardless of age or clinical hydrocele and reveal immunological profiles associated with latency and immune-mediated suppression of parasite transmission.
- ItemEvaluation of Antiwolbachial Treatment in Pathogenesis of Lymphedema Development(2010-07-12) Kwarteng, AlexanderGlobally, filarial LE affects more than 16 million individuals. Registered antifilarial drugs do little to mitigate the pathology. Currently, there is no definite drug for treating subjects who develop the pathology because the Global Programme to Eliminate Lymphatic Filariasis (GPELF) relies only on hygiene management practices as the only source of relieve for this group. Antiwolbachial therapy is therefore believed to be the most promising approach for treating lymphedema. To elucidate the efficacy of anti-wolbachial treatment with antibiotics in lymphedema, 180 individuals were recruited from 25 endemic communities of the Nzema East and Ahanta West Districts of the Western Region of Ghana for a double blind placebo-controlled trial. In all, 119 patients were stratified according to circulating filarial antigen (CFA) status, randomized to receive 200mg/d of doxycycline (n=46), 1000mg/d of amoxicillin (n=36) and placebo (n=38) for 42days in a daily observed treatment. Although minimal significant improvements were seen for almost all parameters measured in the CFA-positive treated with doxycycline, there were remarkable improvement in the CFA-negative doxycycline-treated patients particularly in the area of decreased mossy lesions, healed sores, reduced knobs, regressed leg stage, decreased ultrasound measurements (p=0.0001), reduced filarial acute attacks, halt of disease progression, significant reduction in antigenaemia levels (p=<0.00). In the majority of the patients who received 6 weeks doxycycline treatment, there was a highly significant improvement (43.9%) in the leg stage at the end of the study. Although there was halt of disease progression (61.9%) as well as decreased filarial attacks in the amoxicillin treated group, there was no significant improvement in the amoxicillin as well as the placebotreated patients regarding all other parameters assessed. The study suggests that doxycycline as the first therapy for treating lymphedema and recommends its use as individual drug administration.
- ItemGut Microbiome-Targeted Nutrition Interventions and Growth among Children in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis(Current Developments in Nutrition, 2024-03) Addae, Hammond Yaw; Apprey, Charles; Kwarteng, Alexander; 0000-0002-0174-6862; 0000-0002-4071-5049; 0000-0002-0893-2908Background: Childhood malnutrition is a public health challenge of much interest and concern globally. However, a perturbed gut microbiome (GM) may limit some nutrition interventions’ effects among healthy children with undernutrition. Objectives: This review aimed to evaluate the effects of GM-targeted nutrition interventions on growth outcomes among children (0–59 mo) using published studies in low- and middle-income countries. Methods: The methods were guided by the Cochrane methodology. The literature search was conducted to include articles published from inception to July 2023 in PubMed, Google Scholar, and Cochrane Databases. We identified and included 35 studies among 11,047 children. The analysis was conducted considering various growth parameters in the qualitative synthesis and weight gain (kg) in the meta-analysis. Results: In the qualitative synthesis, 55.6% of prebiotics, 66.7% of probiotics, 71.4% of synbiotics, and 28.6% of “microbiome complementary feed” studies had significant effects on growth outcomes. Also, prebiotics had more studies with significant effects among healthy children, whereas probiotics, synbiotics, and “microbiome complementary feeds” had more studies with significant effects among children with undernutrition. Nineteen studies were included in the meta-analyses, of which 7 (36.8%) measured GM outcomes. The meta-analysis showed that prebiotics exhibited heterogeneity but had significant effects on weight in the intervention as compared with the control (mean difference [MD]: 0.14 kg; 95% CI: 0.02, 0.25; I2 ¼ 63%, P ¼ 0.02; 4 studies, n ¼ 932). Probiotics had significant effects on weight in the intervention (MD: 0.15 kg; 95% CI: 0.06, 0.25; I2 ¼ 42%, P ¼ 0.05; 8 studies, n ¼ 2437) as compared to the control. However, synbiotics (MD: 0.26 kg; 95% CI: –0.04, 0.56; I2 ¼ 41%, P ¼ 0.17; 4 studies, n ¼ 1896] and “microbiome complementary feed” (MD: –0.03 kg; 95% CI: –0.18, 0.11; I2 ¼ 0%, P ¼ 0.60; 3 studies, n ¼ 733] had no significant effects on weight in the intervention as compared with control. Conclusions: Although probiotics and synbiotics may be effective at enhancing growth among children, the selection of interventions should be contingent upon health status
- ItemMolecular characterization of interactions between the D614G variant of SARS-CoV-2 S-protein and neutralizing antibodies: A computational approach(Infection, Genetics and Evolution, 2021) Kwarteng, Alexander; Asiedu, Ebenezer; Sylverken, Augustina Angelina; Larbi, Amma; Sakyi, Samuel Asamoah; Asiedu, Samuel Opoku; 0000-0002-0893-2908; 0000-0003-2867-1984; 0000-0002-7691-914X; 0000-0002-3814-6924; 0000-0001-5168-4762; 0000-0002-0352-3195The D614G variant of SARS-CoV-2 S-protein emerged in early 2020 and quickly became the dominant circulating strain in Europe and its environs. The variant was characterized by the higher viral load, which is not associated with disease severity, higher incorporation into the virion, and high cell entry via ACE-2 and TMPRSS2. Previous strains of the coronavirus and the current SARS-CoV-2 have demonstrated the selection of mutations as a mechanism of escaping immune responses. In this study, we used molecular dynamics simulation and MM-PBSA binding energy analysis to provide insights into the behaviour of the D614G S-protein at the molecular level and describe the neutralization mechanism of this variant. Our results show that the D614G S-protein adopts distinct conformational dynamics which is skewed towards the open-state conformation more than the closed-state conformation of the wild-type S-protein. Residue-specific variation of amino acid flexibility and domain specific RMSD suggest that the mutation causes an allosteric conformational change in the RBD. Evaluation of the interaction energies between the S-protein and neutralizing antibodies show that the mutation may enhance, reduce or not affect the neutralizing interactions depending on the neutralizing antibody, especially if it targets the RBD. The results of this study have shed insights into the behaviour of the D614G S-protein at the molecular level and provided a glimpse of the neutralization mechanism of this variant.
- ItemTranscriptomics and Immune Profiles of Asymptomatic Filarial-Infected Individuals(2015-08) Kwarteng, AlexanderFilarial infections caused by Wuchereria bancroftiand Brugiaspecies (lymphatic filariasis (LF)) and Onchocerca volvulus(onchocerciasis) affect almost 200 million individuals worldwide and pose major public health challengesinendemic regions. Indeed, the collective DALYs (disability-adjusted life years) for both infections is 3.3 million. Infections with these thread-like nematodes are chronic and although most individuals develop a regulated state, a portion develop severe forms of pathology. Mass drug administration (MDA) programmes on endemic populations focus on reducing prevalencelevels of people with microfilariae (MF), the worm's offspringin the bloodto less than 1%. Although this has been successful in some areas, studies show that MDA will be required for longer than initially conceived. Thus, there is still a requirement for better drugs or vaccines.W. bancrofti-infected individuals without pathology (asymptomatic) can be subdivided into two groupsthat are patent (MF+) or latent (MF-). Patent infections are associated with an immunologically tolerant phenotype state that favours worm survival and in addition does not provoke overt pathology in the host. Latent infections are characterized by the lack of MF in the periphery, despite the presence of adult worms, and their immune profiles show markers of immune-mediated MF control. In O. volvulusinfection however, the majority of individuals havedermal-residing MFand amicrofilaridermic (a-MF) individuals appear to be the consequences of repeated MDA treatment. Interestingly, recent research revealed that O. volvulusendemic areas,with a lowered infection pressure due to MDA,appear to influencebystander responsesto Plasmodium-derived antigens in community members even if they have not regularlyparticipated in the therapy.Pathology that arises in either filarial infection is associated with dampened regulatory T cell responses (Treg) and IL-10 but elevated Th17 responses. Thus, identifying immune determinants that drive these different infection stateshas the potential to guide the development of improvedanti-filarial drugsand vaccines. In this study, microarray and cellular profiling approaches were used to evaluate gene expression patterns and to revealgenetic pathways specific to W. bancroftior O. volvulusinfection. Individuals with latentLFinfections showed an enhanced gene expressionprofile, including genes involved in Actin Nucleation by ARP-WASP Complex, Rac signaling, Cdc42 signaling, RhoGD1 signaling, eosinophil effector functions and CD28 signaling in T helper cellpathways. Interestingly, the Charcot-Leyden crystal/galectin-10(CLC/Gal-10), an immunosuppressive molecule,was among the top commonly expressed genes in both infections and elevated levels were also detected in plasma.Moreover, compared to healthy volunteers, T cells recovered from W. bancrofti-infected individuals secreted higher levels of CLC/Gal-10and were even higher in MF+ individuals: by complementingtheir elevated Treg responses (Foxp3/IL-10). LatentW. bancrofti-infected individualson the other hand had pronounced Th1, Th2 and Th17 responses. With regards to filarial-specificantibody responses, IgG4, IgE and IgA in plasma were associated with MF+, MF-and endemic normals, respectively. Overall, the transcriptome profiling revealed overlappinggenes in both infections: CLC/Gal-10, ribonuclease RNase A family, 2(RNASE2) and ribosomal protein S4, y-linked 1(RPS4Y1). Thus, the study offersinsightinto filarial-specific genes, signaling pathways and ivimmune determinants, which may be central targets towards the development of new anti-filarial interventions.
- ItemUse of social media in a national Tuberculosis Drug Resistance Survey: lessons from the first anti-tuberculosis drug resistance survey in Ghana(AAS Open Research, 2019) Sylverken, Augustina Angelina; Owusu-Dabo, Ellis; Kwarteng, Alexander; Twumasi-Ankrah, Sampson; Owusu, Michael; Adu-Amoah, Louis; Dumevi, Rexford Mawunyo; Arthur, Rejoice Agyeiwaa; Addofoh, Nicholas; Dzata, Francisca; Bonsu, Frank; 0000-0002-7691-914X; 0000-0003-4232-4292; 0000-0002-0893-2908; 0000-0002-9183-1883; 0000-0001-5066-150X; 0000-0001-6755-2545; 0000-0002-7135-2754Background: The widespread use of social media applications on mobile phones indicate that smart phones have become more than just a simple medium for voice calling. Several studies have shown the potential benefit of these social media applications in discussing many health conditions. We report on tracking sample transport by public and private transport providers using WhatsApp during the first nationwide drug resistance tuberculosis (TB) survey in Ghana. Methods: The survey was conducted between February 2016 and June 2017, and involved 33 TB diagnostic sites selected on the basis of a two-stage cluster randomized sampling design on both anticipated yield and probability proportional to size method. We engaged the services of privately and publicly owned vehicles’ union to transport samples to the central laboratories in Kumasi for further laboratory processing.We created a mobile social group platform (‘National TBDRS’) on WhatsApp consisting of two representatives from each site as well as other stakeholders. The purpose was to notify a laboratory team in Kumasi, on the following details of the sample: date and time of dispatch, driver’s name, car number, estimated time of arrival, and bus terminal name. Results: A total 3077 WhatsApp messages were received during the survey period. Of these, 2879 (93.57%) messages were related to the survey. We observed a positive correlation between the total number of messages received and the total number of well-packaged sputum samples sent (r=0.89, p=0.02). There were no major transport delays (11:44±03:50) and all samples arrived within a 3-day window from the survey sites. Conclusions: Using WhatsApp as a platform of communication can significantly aid in improving tracking of samples, enhance accountability of for example drivers handling the samples over at a road crossing and communication across health facilities.