Browsing by Author "Lubyayi, Lawrence"

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    Antibody Responses to Schistosoma Mansoni Schistosomula Antigens
    (Parasite immunology, 2018) Egesa, Moses; Lubyayi, Lawrence; Jones, Frances M.; Tukahebwa, Edridah M.; Bagaya, Bernard S.; Dunne, David W.; Elliott, Alison M.; Wilson, Shona; Cose, Stephen
    While antigens from Schistosoma schistosomula have been suggested as potential vaccine candidates, the association between antibody responses with schistosomula antigens and infection intensity at reinfection is not well known. Schistosoma mansoni-infected individuals were recruited from a schistosomiasis endemic area in Uganda (n = 372), treated with 40 mg/kg praziquantel (PZQ) and followed up at five weeks and at one year post-treatment. Pre-treatment and five weeks post-treatment immunoglobulin (Ig) E, IgG1 and IgG4 levels against recombinant schistosomula antigens rSmKK7, rSmLy6A, rSmLy6B and rSmTSP7 were measured using ELISA. Factors associated with detectable pre-treatment or post-treatment antibody response against the schistosomula antigens and the association between five-week antibody responses and one year post-treatment reinfection intensity among antibody responders were examined. Being male was associated with higher pre-treatment IgG1 to rSmKK7, rSmLy6a and AWA. Five weeks post-treatment antibody responses against schistosomula antigens were not associated with one year post-treatment reinfection intensity among antibody responders’ antibody levels against rSmKK7, rSmLy6B and rSmTSP7 dropped, but increased against rSmLy6A, AWA and SEA at five weeks post-treatment among antibody responders. S. mansoni-infected individuals exhibit detectable antibody responses to schistosomula antigens that are affected by treatment. These findings indicate that schistosomula antigens induce highly varied antibody responses and could have implications for vaccine development.
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    Continuous research monitoring improves the quality of research conduct and compliance among research trainees: internal evaluation of a monitoring programme
    (AAS Open Research, 2020) Akello, Mirriam; Coutinho, Sarah; N-Mboowa, Mary Gorrethy; Bukirwa, Victoria D; Natukunda, Agnes; Lubyayi, Lawrence; Nabakooza, Grace; Cose, Stephen; Elliott, Alison M.
    Background: Research site monitoring (RSM) is an effective way to ensure compliance with Good Clinical Practice (GCP). However, RSM is not offered to trainees (investigators) at African Institutions routinely. The Makerere University/Uganda Virus Research Institute Centre of Excellence in Infection and Immunity Research and Training (MUIIPlus) introduced internal monitoring to promote the quality of trainees’ research projects. Here, we share our monitoring model, experiences and achievements, and challenges encountered. Methods: We analysed investigators’ project reports from monitoring visits undertaken from April 2017 to December 2019. Monitors followed a standard checklist to review investigator site files and record forms, and toured site facilities. We planned four monitoring visits for each trainee: one at site initiation, two interim, and a closeout monitoring visit. A team of two monitors conducted the visits. Results: We monitored 25 out of the 26 research projects in progress between April 2017 and December 2019. Compliance with protocols, standard operating procedures, GCP, and GCLP improved with each monitoring visit and all projects achieved 100% compliance at site closeout. All investigators had good work ethics and practice, and appropriate facilities. Initially, some investigators’ files lacked essential documents, and informed consent processes needed to be improved. We realized that non-compliant investigators had not received prior training in GCP/GCLP, so we offered them this training. Conclusions: Routine monitoring helps identify non-compliance early and improves the quality of research. We recommend continuous internal monitoring for all research studies. Investigators conducting research involving human subjects should receive GCP/GCLP training before commencing their projects. Institutional higher degrees and research ethics committees should enforce this as a requirement for project approvals.
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    Evaluation of current rapid HIV test algorithms in Rakai, Uganda
    (Journal of virological methods, 2013) Galiwango, Ronald M.; Musoke, Richard; Lubyayi, Lawrence; Ssekubugu, Robert; Kalibbala, Sarah; Ssekweyama, Viola; Mirembe, Viola; Nakigozi, Gertrude; Reynolds, Steven J.; Serwadda, David; Gray, Ronald H.; Kigozi, Godfrey
    Rapid HIV tests are a crucial component of HIV diagnosis in resource limited settings. In Uganda, the Ministry of Health allows for both serial and parallel HIV rapid testing using Determine, Stat- Pak and Uni-Gold. In serial testing, a non-reactive result on Determine ends testing. The performance of serial and parallel algorithms with Determine and Stat-Pak test kits was assessed. A cross-sectional diagnostic test accuracy evaluation using three rapid HIV test kits as per the recommended parallel test algorithm was followed by EIA-WB testing with estimates of the performance of serial testing algorithm. In 2520 participants tested by parallel rapid algorithms, 0.6% had weakly reactive result. Parallel testing had 99.7% sensitivity and 99.8% specificity. If Stat-Pak was used as the first screening test for a serial algorithm, the sensitivity was 99.6% and specificity 99.7%. However, if Determine was used as the screening test, sensitivity was 97.3% and specificity 99.9%. Serial testing with Stat-Pak as the initial screening test performed as well as parallel testing, but Determine was a less sensitive screen. Serial testing could be cost saving.
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    The Impact of Intensive Versus Standard Anthelminthic Treatment on Allergy-related Outcomes, Helminth Infection Intensity, and Helminth-related Morbidity in Lake Victoria Fishing Communities, Uganda: Results From the LaVIISWA Cluster-randomized Trial
    (Clinical infectious diseases, 2019) Sanya, Richard E.; Nkurunungi, Gyaviira; Hoek Spaans, Remy; Nampijja, Margaret; O’Hara, Geraldine; Kizindo, Robert; Oduru, Gloria; Kabuubi Nakawungu, Prossy; Niwagaba, Emmanuel; Abayo, Elson; Kabagenyi, Joyce; Zziwa, Christopher; Tumusiime, Josephine; Nakazibwe, Esther; Kaweesa, James; Muwonge Kakooza, Fred; Akello, Mirriam; Lubyayi, Lawrence; Verweij, Jaco; Nash, Stephen; Ree, Ronald van; Mpairwe, Harriet; Tukahebwa, Edridah; Webb, Emily L.; Elliott, Alison M.
    The prevalence of allergy-related diseases is increasing in low-income countries. Parasitic helminths, common in these settings, may be protective. We hypothesized that intensive, community-wide, anthelminthic mass drug administration (MDA) would increase allergy-related diseases, while reducing helminth-related morbidity. Methods. In an open, cluster-randomized trial (ISRCTN47196031), we randomized 26 high-schistosomiasis-transmission fishing villages in Lake Victoria, Uganda, in a 1:1 ratio to receive community-wide intensive (quarterly single-dose praziquantel plus albendazole daily for 3 days) or standard (annual praziquantel plus 6 monthly single-dose albendazole) MDA. Primary outcomes were recent wheezing, skin prick test positivity (SPT), and allergen-specific immunoglobulin E (asIgE) after 3 years of intervention. Secondary outcomes included helminths, haemoglobin, and hepatosplenomegaly. Results. The outcome survey comprised 3350 individuals. Intensive MDA had no effect on wheezing (risk ratio [RR] 1.11, 95% confidence interval [CI] 0.64–1.93), SPT (RR 1.10, 95% CI 0.85–1.42), or asIgE (RR 0.96, 95% CI 0.82–1.12). Intensive MDA reduced Schistosoma mansoni infection intensity: the prevalence from Kato Katz examinations of single stool samples from each patient was 23% versus 39% (RR 0.70, 95% CI 0.55–0.88), but the urine circulating cathodic antigen test remained positive in 85% participants in both trial arms. Hookworm prevalence was 8% versus 11% (RR 0.55, 95% CI 0.31–1.00). There were no differences in anemia or hepatospenomegaly between trial arms. Conclusions. Despite reductions in S. mansoni intensity and hookworm prevalence, intensive MDA had no effect on atopy, allergy- related diseases, or helminth-related pathology. This could be due to sustained low-intensity infections; thus, a causal link between helminths and allergy outcomes cannot be discounted. Intensive community-based MDA has a limited impact in high-schistosomiasis- transmission fishing communities, in the absence of other interventions.
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    Infection with HIV-1 subtype D among Acutely Infected Ugandans is Associated with Higher Median Concentration of Cytokines Compared to Subtype
    (IJID Regions, 2022) Kapaata, Anne; Balinda, Sheila N.; Kikaire, Bernard; Egesa, Moses; Lubyayi, Lawrence; Macharia, Gladys N.; Kamali, Anatoli; Gilmour, Jill; Bagaya, Bernard; Salazar-Gonzalez, Jesus F.; Kaleebu, Pontiano
    The observation that HIV-1 subtype D progresses faster to disease than subtype A prompted us to examine cytokine levels early after infection within the predominant viral subtypes that circulate in Uganda and address the following research questions: (1) Do cytokine levels vary between subtypes A1 and D? (2) Do cytokine profiles correlate with disease outcomes? To address these questions, HIV-1 subtypes were determined by population sequencing of the HIV-1 pol gene and 37 plasma cytokine concentrations were evaluated using V-Plex kits on Meso Scale Discovery platform in 65 recent sero-converters. HIV-1 subtype D (pol) infections exhibited significantly higher median plasma concentrations of IL-5, IL-16, IL-1α, IL-7, IL-17A, CCL11 (Eotaxin-1), CXCL10 (IP-10), CCL13 (MCP-4) and VEGF-D compared to subtype A1 (pol) infections. We also found that IL-12/23p40 and IL-1α were associated with faster CD4+T cell count decline, while bFGF was associated with maintenance of CD4+ counts above 350 cells/microliter. Our results suggest that increased production of cytokines in early HIV infection may trigger a disruption of the immune environment and contribute to pathogenic mechanisms underlying the accelerated disease progression seen in individuals infected with HIV-1 subtype D in Uganda.
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    Risk factors for asthma among schoolchildren who participated in a casecontrol study in urban Uganda
    (Elife, 8,, 2019) Mpairwe, Harriet; Namutebi, Milly; Nkurunungi, Gyaviira; Tumwesige, Pius; Nambuya, Irene; Mukasa, Mike; Onen, Caroline; Nnaluwooza, Marble; Apule, Barbara; Katongole, Tonny; Oduru, Gloria; Kahwa, Joseph; Webb, Emily L; Lubyayi, Lawrence; Pearce, Neil; Elliott, Alison M
    Data on asthma aetiology in Africa are scarce. We investigated the risk factors for asthma among schoolchildren (5–17 years) in urban Uganda. We conducted a case-control study, among 555 cases and 1115 controls. Asthma was diagnosed by study clinicians. The main risk factors for asthma were tertiary education for fathers (adjusted OR (95% CI); 2.32 (1.71–3.16)) and mothers (1.85 (1.38–2.48)); area of residence at birth, with children born in a small town or in the city having an increased asthma risk compared to schoolchildren born in rural areas (2.16 (1.60–2.92)) and (2.79 (1.79–4.35)), respectively; father’s and mother’s history of asthma; children’s own allergic conditions; atopy; and cooking on gas/electricity. In conclusion, asthma was associated with a strong rural-town-city risk gradient, higher parental socio-economic status and urbanicity. This work provides the basis for future studies to identify specific environmental/lifestyle factors responsible for increasing asthma risk among children in urban areas in LMICs.
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    Schistosoma Mansoni schistosomula Antigens Induce Th1/ Pro-inflammatory Cytokine Responses
    (Parasite immunology, 2018) Egesa, Moses; Lubyayi, Lawrence; Tukahebwa, Edridah M.; Bagaya, Bernard S.; Wilson, Shona; Yazdanbakhsh, Maria; Labuda, Lucja A.; Cose, Stephen
    Larvae of Schistosoma (schistosomula) are highly susceptible to host immune responses and are attractive prophylactic vaccine targets, although cellular immune responses against schistosomula antigens in endemic human populations are not well characterized. We collected blood and stool from 54 Schistosoma mansoni-infected Ugandans, isolated peripheral blood mononuclear cells and stimulated them for 24 hours with schistosome adult worm and soluble egg antigens (AWA and SEA), along with schistosomula recombinant proteins rSmKK7, Lymphocyte Antigen 6 isoforms (rSmLy6A and rSmLy6B), tetraspanin isoforms (rSmTSP6 and rSmTSP7). Cytokines, chemokines and growth factors were measured in the culture supernatants using a multiplex luminex assay, and infection intensity was determined before and at 1 year after praziquantel (PZQ) treatment using the Kato-Katz method. Cellular responses were grouped and the relationship between groups of correlated cellular responses and infection intensity before and after PZQ treatment was investigated. AWA and SEA induced mainly Th2 responses. In contrast, rSmLy6B, rSmTSP6 and rSmTSP7 induced Th1/pro-inflammatory responses. While recombinant antigens rSmKK7 and rSmLy6A did not induce a Th1/pro-inflammatory response, they had an association with pre-treatment infection intensity after adjusting for age and sex. Testing more schistosomula antigens using this approach could provide immune-epidemiology identifiers necessary for prioritizing next generation schistosomiasis vaccine candidates.