Theresa M. Rossouw

Persistent Microbial Translocation and Immune Activation in HIV-1-Infected South Africans Receiving Combination Antiretroviral Therapy

BACKGROUND Microbial translocation contributes to immune activation and disease progression during chronic human immunodeficiency virus type 1 (HIV-1) infection. However, its role in the African AIDS epidemic remains controversial. Here, we investigated the relationship between markers of monocyte activation, plasma lipopolysaccharide (LPS), and HIV-1 RNA in South Africans prioritized to receive combination antiretroviral therapy (cART). METHODS Ten HIV-1-negative African controls and 80 HIV-1-infected patients with CD4 T cell counts <200 cells/microL were sampled prior to (n=60) or during (n=20) receipt of effective cART. Viral load was measured by Nuclisens; LPS by the Limulus amoebocyte lysate assay; monocyte and T cell subsets by flow cytometry; and soluble CD14, cytokines, and chemokines by enzyme-linked immunosorbent assay and customized Bio-Plex plates. RESULTS Three distinct sets of markers were identified. CCL2, CXCL10, and CD14(+)CD16(+) monocyte levels were positively correlated with HIV-1 viremia. This finding, together with cART-induced normalization of these markers, suggests that their upregulation was driven by HIV-1. Plasma interleukin-6 was associated with the presence of opportunistic coinfections. Soluble CD14 and tumor necrosis factor were linked to plasma LPS levels and, as observed for LPS, remained elevated in patients receiving effective cART. CONCLUSIONS Microbial translocation is a major force driving chronic inflammation in HIV-infected Africans receiving cART. Prevention of monocyte activation may be especially effective at enhancing therapeutic outcomes.

Prevalence of scientific misconduct among a group of researchers in Nigeria.

BACKGROUND There is a dearth of information on the prevalence of scientific misconduct from Nigeria. OBJECTIVES This study aimed at determining the prevalence of scientific misconduct in a group of researchers in Nigeria. Factors associated with the prevalence were ascertained. METHOD A descriptive study of researchers who attended a scientific conference in 2010 was conducted using the adapted Scientific Misconduct Questionnaire-Revised (SMQ-R). RESULTS Ninety-one researchers (68.9%) admitted having committed at least one of the eight listed forms of scientific misconduct. Disagreement about authorship was the most common form of misconduct committed (36.4%) while plagiarism was the least (9.2%). About 42% of researchers had committed falsification of data or plagiarism. Analysis of specific acts of misconduct showed that committing plagiarism was inversely associated with years in research (Fisher exact p-value = 0.02); falsifying data was related to perceived low effectiveness of the institutions rules and procedures for reducing scientific misconduct (X(2) = 6.44, p-value = 0.01); and succumbing to pressure from study sponsor to engage in unethical practice was related to sex of researcher (Fisher exact p-value = 0.02). CONCLUSIONS The emergent data from this study is a cause for serious concern and calls for prompt intervention. The best response to reducing scientific misconduct will proceed from measures that contain both elements of prevention and enforcement. Training on research ethics has to be integrated into the curriculum of undergraduate and postgraduate students while provision should be made for in-service training of researchers. Penalties against acts of scientific misconduct should be enforced at institutional and national levels.

Circulating biomarkers of immune activation distinguish viral suppression from nonsuppression in HAART-treated patients with advanced HIV-1 subtype C infection.

Few studies have examined immune activation profiles in patients with advanced HIV-1 subtype C infection or assessed their potential to predict responsiveness to HAART. BioPlex, ELISA, and nephelometric procedures were used to measure plasma levels of inflammatory biomarkers in HIV-1 subtype C-infected patients sampled before and after 6 months of successful HAART (n = 20); in patients failing HAART (n = 30); and in uninfected controls (n = 8). Prior to HAART, CXCL9, CXCL10, β2M, sTNF-R1, TGF-β1, IFN-γ, IL-6, TNF, and sCD14 were significantly elevated in HIV-1-infected patients compared to controls (P < 0.01). All of these markers, with the exception of sTNF-R1, were also elevated in patients failing HAART (P < 0.05). The persistently elevated levels of CXCL9, CXCL10, and β2M in patients failing therapy in the setting of a marked reduction in these markers in patients on successful HAART suggest that they may be useful not only to monitor immune activation during HAART, but also to distinguish between good and poor responders. In the case of sCD14 and TGF-β1, the levels of these biomarkers remained persistently elevated despite HAART-induced virological suppression, a finding that is consistent with ongoing monocyte-macrophage activation, underscoring a potential role for adjuvant anti-inflammatory therapy.

It's my blood: ethical complexities in the use, storage and export of biological samples: perspectives from South African research participants

BackgroundThe use of biological samples in research raises a number of ethical issues in relation to consent, storage, export, benefit sharing and re-use of samples. Participant perspectives have been explored in North America and Europe, with only a few studies reported in Africa. The amount of research being conducted in Africa is growing exponentially with volumes of biological samples being exported from the African continent. In order to investigate the perspectives of African research participants, we conducted a study at research sites in the Western Cape and Gauteng, South Africa.MethodsData were collected using a semi-structured questionnaire that captured both quantitative and qualitative information at 6 research sites in South Africa. Interviews were conducted in English and Afrikaans. Data were analysed both quantitatively and qualitatively.ResultsOur study indicates that while the majority of participants were supportive of providing samples for research, serious concerns were voiced about future use, benefit sharing and export of samples. While researchers view the provision of biosamples as a donation, participants believe that they still have ownership rights and are therefore in favour of benefit sharing. Almost half of the participants expressed a desire to be re-contacted for consent for future use of their samples. Interesting opinions were expressed with respect to export of samples.ConclusionsEliciting participant perspectives is an important part of community engagement in research involving biological sample collection, export, storage and future use. A tiered consent process appears to be more acceptable to participants in this study. Eliciting opinions of researchers and research ethics committee (REC) members would contribute multiple perspectives. Further research is required to interrogate the concept of ownership and the consent process in research involving biological samples.

Impact of HIV infection and smoking on lung immunity and related disorders

HIV-infected persons not only have higher rates of smoking than the general population, but are also unusually vulnerable to the associated adverse health effects, both infective and noninfective in origin. Indeed, in the setting of well-organised care and availability of highly active antiretroviral therapy, HIV-infected smokers lose more life-years to smoking than to HIV infection per se, presenting a major challenge to healthcare providers. Not surprisingly, the respiratory system is particularly susceptible to the damaging interactive chronic inflammatory and immunosuppressive effects of HIV and smoking, intensifying the risk of the development of opportunistic infections, as well as lung cancer and obstructive lung disorders. The impact of smoking on the immunopathogenesis and frequencies of these respiratory conditions in the setting of HIV infection, as well as on the efficacy of antiretroviral therapy, represent the primary focus of this review. Smoking exacerbates the immunosuppressive/pro-inflammatory effects of HIV, increasing the risk of pulmonary disease http://ow.ly/Oe9hE

Misconduct in research : a descriptive survey of attitudes, perceptions and associated factors in a developing country

BackgroundMisconduct in research tarnishes the reputation, credibility and integrity of research institutions. Studies on research or scientific misconduct are still novel in developing countries. In this study, we report on the attitudes, perceptions and factors related to the work environment thought to be associated with research misconduct in a group of researchers in Nigeria - a developing country.MethodA survey of researchers attending a scientific conference was done using an adapted Scientific Misconduct Questionnaire-Revised (SMQ-R). Initial descriptive analysis of individual items using frequencies and proportions for all quantitative data was performed. Thereafter, Likert scale responses were transformed into dichotomous responses. Fisher exact test was performed for associations as appropriate. A two-tailed p-value of less than 0.05 was accepted as significant.ResultHalf of the respondents (50.4%) were aware of a colleague who had committed misconduct, defined as “non-adherence to rules, regulations, guidelines, and commonly accepted professional codes or norms”. Over 88% of the researchers were concerned about the perceived amount of misconduct prevalent in their institution and 96.2% believed that one or more forms of scientific misconduct had occurred in their workplace. More than half (52.7%) rated the severity of penalties for scientific misconduct in their work environment as low. Furthermore¸ the majority (56.1%) were of the view that the chance of getting caught for scientific misconduct in their work environment was low.ConclusionResearchers in Nigeria perceive that scientific misconduct is commonplace in their institutions, but are however worried about the negative effects of scientific misconduct on the credibility of scientific research. We recommend that researchers be empowered with the knowledge and virtues necessary for self-regulation that advance research integrity. Research institutions should however also step into their role of fostering a responsible research ethic and discouraging misconduct.

Impaired CD4+ T-Cell Restoration in the Small Versus Large Intestine of HIV-1–Positive South Africans Receiving Combination Antiretroviral Therapy

BACKGROUND Human immunodeficiency virus type 1 (HIV-1) infection is associated with a massive depletion of intestinal CD4(+) T cells that is only partially reversed by combination antiretroviral therapy (cART). Here, we assessed the ability of nucleoside reverse-transcriptase inhibitor/nonnucleoside reverse-transcriptase inhibitor treatment to restore the CD4(+) T-cell populations in the intestine of South African patients with AIDS. METHODS Thirty-eight patients with advanced HIV-1 infection who had chronic diarrhea (duration, >4 weeks) and/or unintentional weight loss (>10% decrease from baseline) of uncertain etiology were enrolled. Blood specimens were collected monthly, and gastrointestinal tract biopsy specimens were collected before cART initiation (from the duodenum, jejunum, ileum, and colon), 3 months after cART initiation (from the duodenum), and 6 months after cART initiation (from the duodenum and colon). CD4(+), CD8(+), and CD38(+)CD8(+) T cells were quantified by flow cytometry and immunohistochemistry analyses, and the HIV-1 RNA load was determined by the Nuclisens assay. RESULTS CD4(+) T-cell and HIV-1 RNA levels were significantly lower, whereas CD8(+) T-cell levels, including activated CD38(+)CD8(+) T cell levels, were higher in the duodenum and jejunum, compared with the colon. After 6 months of cART, a significant but incomplete recovery of CD4(+) T cells was detected in the colon and peripheral blood but not in the duodenum. Failed restoration of the CD4(+) T-cell count in the duodenum was associated with nonspecific enteritis and CD8(+) T-cell activation. CONCLUSIONS Strategies that target inflammation and immune activation in the small intestine may be required to expedite CD4(+) T-cell recovery and improve therapeutic outcomes.

QuantiFERON-TB GOLD ELISA assay for the detection of Mycobacterium tuberculosis-specific antigens in blood specimens of HIV-positive patients in a high-burden country

Tuberculosis is a life-threatening infection worldwide. Despite improvements in therapy, it results in 2 million deaths and 9 million new cases annually. This study evaluated the use of the QuantiFERON-TB GOLD enzyme-linked immunosorbent assay in a high HIV/TB burden setting in an ARV clinic at the Tshwane District Hospital, South Africa. The sensitivity and specificity of the QF assay in the clinic were 30% (9/30) and 63% (19/30), respectively, when compared with the gold standard culture results. Analysis also suggested that the sensitivity of the QuantiFERON assay is determined by a limiting patient CD4 value between 150 and 200.

CD14 + macrophages that accumulate in the colon of African AIDS patients express pro-inflammatory cytokines and are responsive to lipopolysaccharide

BackgroundIntestinal macrophages are key regulators of inflammatory responses to the gut microbiome and play a central role in maintaining tissue homeostasis and epithelial integrity. However, little is known about the role of these cells in HIV infection, a disease fuelled by intestinal inflammation, a loss of epithelial barrier function and increased microbial translocation (MT).MethodsPhenotypic and functional characterization of intestinal macrophages was performed for 23 African AIDS patients with chronic diarrhea and/or weight loss and 11 HIV-negative Africans with and without inflammatory bowel disease (IBD). AIDS patients were treated with cotrimoxazole for the prevention of opportunistic infections (OIs). Macrophage phenotype was assessed by flow cytometry and immuno-histochemistry (IHC); production of proinflammatory mediators by IHC and Qiagen PCR Arrays; in vitro secretion of cytokines by the Bio-Plex Suspension Array System. Statistical analyses were performed using Spearman’s correlation and Wilcoxon matched-pair tests. Results between groups were analyzed using the Kruskal-Wallis with Dunn’s post-test and the Mann–Whitney U tests.ResultsNone of the study participants had evidence of enteric co-infections as assessed by stool analysis and histology. Compared to healthy HIV-negative controls, the colon of AIDS patients was highly inflamed with increased infiltration of inflammatory cells and increased mRNA expression of proinflammatory cytokine (tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IFN-γ, and IL-18), chemokines (chemokine (C-C motif) ligand (CCL)2 and chemokine (C-X-C) motif ligand (CXCL)10) and transcription factors (TNF receptor-associated factor (TRAF)6 and T-box (TXB)21). IHC revealed significant co-localization of TNF-α and IL-1β with CD68+ cells. As in IBD, HIV was associated with a marked increase in macrophages expressing innate response receptors including CD14, the co-receptor for lipopolysaccharide (LPS). The frequency of CD14+ macrophages correlated positively with plasma LPS, a marker of MT. Total unfractionated mucosal mononuclear cells (MMC) isolated from the colon of AIDS patients, but not MMC depleted of CD14+ cells, secreted increased levels of proinflammatory cytokines ex vivo in response to LPS.ConclusionsIntestinal macrophages, in the absence of overt OIs, play an important role in driving persistent inflammation in HIV patients with late-stage disease and diarrhea. These results suggest intensified treatment strategies that target inflammatory processes in intestinal macrophages may be highly beneficial in restoring the epithelial barrier and limiting MT in HIV-infected patients.

Southern African Treatment Resistance Network (SATuRN) RegaDB HIV drug resistance and clinical management database: supporting patient management, surveillance and research in southern Africa

Abstract Substantial amounts of data have been generated from patient management and academic exercises designed to better understand the human immunodeficiency virus (HIV) epidemic and design interventions to control it. A number of specialized databases have been designed to manage huge data sets from HIV cohort, vaccine, host genomic and drug resistance studies. Besides databases from cohort studies, most of the online databases contain limited curated data and are thus sequence repositories. HIV drug resistance has been shown to have a great potential to derail the progress made thus far through antiretroviral therapy. Thus, a lot of resources have been invested in generating drug resistance data for patient management and surveillance purposes. Unfortunately, most of the data currently available relate to subtype B even though >60% of the epidemic is caused by HIV-1 subtype C. A consortium of clinicians, scientists, public health experts and policy markers working in southern Africa came together and formed a network, the Southern African Treatment and Resistance Network (SATuRN), with the aim of increasing curated HIV-1 subtype C and tuberculosis drug resistance data. This article describes the HIV-1 data curation process using the SATuRN Rega database. The data curation is a manual and time-consuming process done by clinical, laboratory and data curation specialists. Access to the highly curated data sets is through applications that are reviewed by the SATuRN executive committee. Examples of research outputs from the analysis of the curated data include trends in the level of transmitted drug resistance in South Africa, analysis of the levels of acquired resistance among patients failing therapy and factors associated with the absence of genotypic evidence of drug resistance among patients failing therapy. All these studies have been important for informing first- and second-line therapy. This database is a free password-protected open source database available on www.bioafrica.net. Database URL: http://www.bioafrica.net/regadb/