Browsing by Author "McAnda, Shirley"
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- ItemProspective evaluation of host biomarkers other than interferon gamma in QuantiFERON Plus supernatants as candidates for the diagnosis of tuberculosis in symptomatic individuals(Elsevier, 2019-07-15) Manngo, Portia M.; Gutschmidt, Andrea; Snyders, Candice I.; Mutavhatsindi, Hygon; Manyelo, Charles M.; Makhoba, Nonjabulo S.; Ahlers, Petri; Hiemstra, Andriette; Stanley, Kim; McAnda, Shirley; Kidd, Martin; Malherbe, Stephanus T.; Walzl, Gerhard; Chegou, Novel N.Background: There is an urgent need for new tools for the diagnosis of TB. We evaluated the usefulness recently described host biomarkers in supernatants from the newest generation of the QuantiFERON test (QuantiFERON Plus) as tools for the diagnosis of active TB. Methods: We recruited individuals presenting at primary health care clinics in Cape Town, South Africa with symptoms requiring investigation for TB disease, prior to the establishment of a clinical diagnosis. Participants were later classified as TB or other respiratory diseases (ORD) based on the results of clinical and laboratory tests. Using a multiplex platform, we evaluated the concentrations of 37 host biomarkers in QuantiFERON Plus supernatants from study participants as tools for the diagnosis of TB. Results: Out of 120 study participants, 35(29.2%) were diagnosed with active TB, 69(57.5%) with ORD whereas 16(13.3%) were excluded. 14(11.6%) of the study participants were HIV infected. Although individ- ual host markers showed potential as diagnostic candidates, the main finding of the study was the identi- fication of a six-marker biosignature in unstimulated supernatants (Apo-ACIII, CXCL1, CXCL9, CCL8, CCL-1, CD56) which diagnosed TB with sensitivity and specificity of 73.9%(95% CI; 51.6–87.8) and 87.6%(95% CI; 77.2–94.5), respectively, after leave-one-out cross validation. Combinations between TB-antigen specific biomarkers also showed potential (sensitivity of 77.3% and specificity of 69.2%, respectively), with multi- ple biomarkers being significantly different between TB patients, Quantiferon Plus Positive and Quantif- eron Plus negative individuals with ORD, regardless of HIV status. Conclusions: Biomarkers detected in QuantiFERON Plus supernatants may contribute to adjunctive diag- nosis of TB.
- ItemTargeting of myeloid-derived suppressor cells by all-trans retinoic acid as host-directed therapy for human tuberculosis(Elsevier Inc., 2021-06) Leukes, Vinzeigh N.; Dorhoi, Anca; Malherbe, Stephanus T.; Maasdorp, Elizna; Khoury, Justine; McAnda, Shirley; Walzl, Gerhard; Du Plessis, NelitaConventional anti-tuberculosis (TB) therapies comprise lengthy antibiotic treatment regimens, exacerbated by multi-drug resistant and extensively drug resistant mycobacterial strains. We assessed the ability of all-trans retinoic acid (ATRA), as repurposed compound serving as host-directed therapy (HDT), to counteract the suppressive effects of myeloid-derived suppressor cells (MDSCs) obtained from active TB cases (untreated or during week one of treatment) on T-cell responsiveness. We show for the first time that MDSCs suppress non-specific T-cell activation and production of interleukin (IL)-2, IL-4, IL-13 and GM-CSF via contact-dependent mechanisms. ATRA treatment decreases MDSC frequency, but fails to mature MDSCs to non-suppressive, terminally differentiated myeloid cells and does not restore T-cell function or cytokine production in the presence of MDSCs. The impact of ATRA treatment on improved immunity, using the concentration tested here, is likely to be minimal, but further identification and development of MDSC-targeting TB host-directed therapies are warranted.