Browsing by Author "Verburgh Estelle"

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    Diagnostic yield of tuberculosis investigations on bone marrow biopsy samples in HIV positive patients at Groote Schuur Hospital
    (2023) Baloyi, Xikombiso; Moodley, Clinton; Verburgh Estelle
    Background: Acid fast bacilli (AFB) staining on bone marrow samples has low sensitivity for diagnosing HIVassociated tuberculosis and Tuberculosis (TB) culture results may be delayed. The GeneXpert® MTB/RIF Ultra assay may provide a more sensitive diagnostic test on bone marrow biopsy samples. Methods: We conducted a two-stage study in a tertiary hospital in South Africa, initially assessing the retrospective yield of TB diagnoses on bone marrow biopsies in adult HIV-positive participants retrospectively from 01-01-2019 to 31-07-2020. Subsequently, determining the prospective yield and diagnostic performance of the GeneXpert® MTB/RIF Ultra assay on bone marrow aspirate and peripheral blood samples in adult HIV-positive participants undergoing bone marrow biopsy from 11- 08-2020 to 31-01-2021. Results: One hundred and twenty-two biopsies were analysed, of which 59/122 were performed for haematological malignancy staging. Granulomata with AFB were detected in six samples, and nine new lymphoma diagnoses were made. Bone marrow TB culture detected only one non-tuberculous mycobacterial infection. All 17 participants who had TB diagnosed from another clinical site were bone marrow TB culture negative. TB treatment was confirmed in 11/33 participants recruited prospectively. One trace positive GeneXpert® MTB/RIF Ultra result on peripheral blood was detected. All TB cultures on bone marrow aspirates and peripheral blood were negative. Conclusion: In a tertiary care hospital in South Africa, the utility of TB culture and GeneXpert® MTB/RIF Ultra on bone marrow aspirate specimens in HIV-positive participants was limited. We postulate that the initiation of empiric anti-tuberculosis treatment could have resulted in false negative results.
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    Diffuse large B-cell lymphoma in a South African cohort with a high HIV prevalence: an analysis by cell-oforigin, Epstein-Barr virus infection and survival
    (2022) Cassim, Sumaiya; Antel, Katherine; Verburgh Estelle
    Introduction: Diffuse large B-cell lymphoma, not otherwise specified (DLBCL NOS) is subdivided according to the cell-of-origin (COO) classification into germinal centre B-cell (GCB) and activated B-cell (ABC) subtypes, each with different molecular profiles and clinical behaviour. This study aims to describe the pattern of the COO subtypes, the proportion of Epstein-Barr virus (EBV) co-infection, and their influence on survival outcomes in a setting of high HIV prevalence. Materials and Methods: This retrospective cohort study included patients diagnosed with de novo DLBCL NOS at our tertiary academic centre in Cape Town, South Africa over a 14-year period. Immunohistochemical stains were performed for COO classification, according to the Hans algorithm. Tumour EBV co-infection was established by EBV-encoded ribonucleic acid in situ hybridisation (EBER-ISH) staining. The effect of the COO subtypes and EBV co-infection on overall survival were described by means of univariate, bivariate and multivariate analyses. Results: A total of 181 patients with DLBCL NOS were included, which comprised 131 HIV-uninfected and 50 HIV-infected patients. There was an equal distribution of GCB and ABC subtypes in the HIV-infected and HIV-uninfected groups. EBV co-infection was detected in 16% of the HIV-infected cases and in 7% of the HIV-uninfected cases (p=0.09). There was no significant difference in the incidence of EBV co-infection between the GCB and ABC subtypes (p=0.67). HIV-infected patients with CD4≥150 cells/mm3 had similar survival to HIV-uninfected patients (p=0.005). Multivariate regression analysis showed that in the HIVinfected group with marked immunosuppression (CD4 <150 cells/mm3), there was significantly poorer overall survival compared to the HIV-uninfected group (HR 2.4, 95% CI 1.3–4.1). There were no statistically significant differences in overall survival by DLBCL COO subtype. Conclusions: There was no difference in the proportion of DLBCL COO subtypes, regardless of HIV status. EBV co-infection was more common in the HIV-infected group, but less than described in the literature. Unexpectedly, there were no significant differences in survival outcomes between the GCB and ABC subtypes. Higher CD4 counts in the HIV-infected group had good survival outcomes, while lower CD4 counts predicted adverse survival outcomes. Further research is needed to explore the genetic mutational landscape of HIVassociated DLBCL.