Browsing by Author "Rangaka, Molebogeng X"

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    Altered ratio of IFN-γ/IL-10 in patients with drug resistant Mycobacterium tuberculosis and HIV-tuberculosis immune reconstitution inflammatory syndrome
    (Public Library of Science, 2012) Skolimowska, Keira H; Rangaka, Molebogeng X; Meintjes, Graeme; Pepper, Dominique J; Seldon, Ronnett; Matthews, Kerryn; Wilkinson, Robert J; Wilkinson, Katalin A
    We have described a clinical relationship between HIV-Tuberculosis Immune Reconstitution Inflammatory Syndrome (TB-IRIS) and anti-tubercular drug resistance. Here we studied the immune response of TB-IRIS patients from whom a drug-resistant (n = 11) or drug-susceptible (n = 25) Mycobacterium tuberculosis (MTB) strain was isolated after presenting with TB-IRIS. ELISpot analysis and multiplex cytokine analysis of the supernatant collected from peripheral blood mononuclear cells stimulated overnight with the heat-killed H37Rv MTB laboratory strain was used. Although there was no statistical difference in IFN-gamma ELISpot responses between the two groups, the results point towards higher bacterial load in the drug-resistant patients, possibly due to failed therapy. The ratio between secreted IFN-gamma/IL-10 and IL-2/IL-10 was significantly lower in TB-IRIS patients in whom the cause of TB was a drug-resistant strain compared to those with a fully sensitive strain (p = 0.02). Since host immune responses are dependent on the bacterial load, we hypothesise that the impaired cytokine balance is likely to be caused by the poorly controlled bacterial growth in these patients.
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    Pneumocystis jirovecii pneumonia in tropical and low and middle income countries: a systematic review and meta-regression
    (Public Library of Science, 2013) Lowe, David M; Rangaka, Molebogeng X; Gordon, Fabiana; James, Chris D; Miller, Robert F
    Objective: Pneumocystis jirovecii pneumonia (PCP), the commonest opportunistic infection in HIV-infected patients in the developed world, is less commonly described in tropical and low and middle income countries (LMIC). We sought to investigate predictors of PCP in these settings. Design Systematic review and meta-regression. METHODS: Meta-regression of predictors of PCP diagnosis (33 studies). Qualitative and quantitative assessment of recorded CD4 counts, receipt of prophylaxis and antiretrovirals, sensitivity and specificity of clinical signs and symptoms for PCP, co-infection with other pathogens, and case fatality (117 studies). RESULTS: The most significant predictor of PCP was per capita Gross Domestic Product, which showed strong linear association with odds of PCP diagnosis (p<0.0001). This was not explained by study design or diagnostic quality. Geographical area, population age, study setting and year of study also contributed to risk of PCP. Co-infection was common (444 episodes/1425 PCP cases), frequently with virulent organisms. The predictive value of symptoms, signs or simple tests in LMIC settings for diagnosis of PCP was poor. Case fatality was >30%; treatment was largely appropriate. Prophylaxis appeared to reduce the risk for development of PCP, however 24% of children with PCP were receiving prophylaxis. CD4 counts at presentation with PCP were usually <200×10 3/ ml. CONCLUSIONS: There is a positive relationship between GDP and risk of PCP diagnosis. Although failure to diagnose infection in poorer countries may contribute to this, we also hypothesise that poverty exposes at-risk patients to a wide range of infections and that the relatively non-pathogenic P. jirovecii is therefore under-represented. As LMIC develop economically they eliminate the conditions underlying transmission of virulent infection: P. jirovecii , ubiquitous in all settings, then becomes a greater relative threat.
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    Randomized placebo-controlled trial of prednisone for paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome
    (Lippincott, Williams & Wilkins, 2010) Meintjes, Graeme; Wilkinson, Robert J; Morroni, Chelsea; Pepper, Dominique J; Rebe, Kevin; Rangaka, Molebogeng X; Oni, Tolu; Maartens, Gary
    Objective: Paradoxical tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is a frequent complication of antiretroviral therapy in resource-limited countries. We aimed to assess whether a 4 week course of prednisone would reduce morbidity in patients with paradoxical TB-IRIS without excess adverse events. Design: A randomised double blind placebo-controlled trial of prednisone (1.5mg/kg/day for 2 weeks then 0.75mg/kg/day for 2 weeks). Patients with immediately life-threatening TB-IRIS manifestations were excluded. Methods: The primary combined endpoint was days of hospitalization and outpatient therapeutic procedures, which were counted as one hospital day. Results: 110 participants were enrolled (55 to each arm). The primary combined endpoint was more frequent in the placebo than the prednisone arm (median hospital days 3 (IQR 0-9) and 0 (IQR 0-3) respectively; p=0.04). There were significantly greater improvements in symptoms, Karnofsky score, and quality of life (MOS-HIV) in the prednisone versus the placebo arm at 2 and 4 weeks, but not at later timepoints. Chest radiographs improved significantly more in the prednisone arm at weeks 2 (p=0.002) and 4 (p=0.02). Infections on study medication occurred in more participants in prednisone than placebo arm (27 vs 17 respectively; p=0.05), but there was no difference in severe infections (2 vs 4 respectively; p=0.40). Isolates from 10 participants were found to be resistant to rifampicin after enrollment. Conclusions: Prednisone reduced the need for hospitalisation and therapeutic procedures, and hastened improvements in symptoms, performance and quality of life. It is important to investigate for drug-resistant tuberculosis and other causes for deterioration before administering glucocorticoids.