Browsing by Author "Antwi-Berko, Daniel"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Blood 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; 0000-0001-8500-0963
    Background 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.
  • Thumbnail Image
    Item
    The impact of ivermectin mass drug administration on the level of endemicity and intensity of Onchocerca Volvulus infection in the Adansi South District of Ghana
    (2014-08-26) Antwi-Berko, Daniel
    Onchocerca volvulus infection remains a major public health problem with more than 120 million people estimated to be living in endemic areas, majority in sub-Saharan Africa. Clinical manifestations include severe dermatitis, visual impairment, and blindness. Ivermectin has been the main operational drug for the treatment and control of onchocerciasis. However reports have emerged about sub-optimal response to this drug in Ghana posing a challenge to the control of O. volvulus infection. In this study, the impact of ivermectin mass drug administration on the level of endemicity and intensity of O. volvulus infection was assessed. About 1223 volunteers from 19 hyperendemic communities in two sub-district areas, who had received 3 to 5 rounds of ivermectin were examined by palpation for onchocercal nodules. Out of the 1223 volunteers, 444 were assessed for microfilaria loads and the community microfilarial load (CMFL) for each of the study communities was determined. Level of endemicity was measured using onchocercal nodule and microfilarial prevalence while the intensity of infection was measured by CMFL, a reference index used by the OCP. At the end of the study, 41.8% of the 1223 volunteers were nodule positive. A significant difference was observed (p=0.0107) in the nodule prevalence between New Edubiase and Akrofuom sub-districts. Of the 444 volunteers, 54.5% were microfilaria positive. The microfilaria prevalence and community microfilarial load in the study communities ranged from 13.3% to 88.9% and 1.4mf/mg to 5.2mf/mg respectively. There was no significant difference in the microfilarial prevalence (p=1.000) and CMFL (p=0.3539) between the two study areas. The overall nodule and microfilarial prevalence in the study areas suggest that these areas are mesoendemic for O. volvulus infection and the intensity of infection as suggested by an average CMFL of 2.7mf/mg is below APOC’s threshold of 5mf/s. This study has shown that 3 to 5 rounds of ivermectin treatment has significant impact on the level of endemicity and intensity of O. volvulus infection which means ivermectin still remains an effective tool for the control of onchocerciasis.