Effectiveness of tests to detect the presence of SARS-CoV-2 virus, and antibodies to SARS-CoV-2, to inform COVID-19 diagnosis: a rapid systematic review.

OBJECTIVES: We undertook a rapid systematic review with the aim of identifying evidence that could be used to answer the following research questions: (1) What is the clinical effectiveness of tests that detect the presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to inform COVID-19 diagnosis? (2) What is the clinical effectiveness of tests that detect the presence of antibodies to the SARS-CoV-2 virus to inform COVID-19 diagnosis? DESIGN AND SETTING: Systematic review and meta-analysis of studies of diagnostic test accuracy. We systematically searched for all published evidence on the effectiveness of tests for the presence of SARS-CoV-2 virus, or antibodies to SARS-CoV-2, up to 4 May 2020, and assessed relevant studies for risks of bias using the QUADAS-2 framework. MAIN OUTCOME MEASURES: Measures of diagnostic accuracy (sensitivity, specificity, positive/negative predictive value) were the main outcomes of interest. We also included studies that reported influence of testing on subsequent patient management, and that reported virus/antibody detection rates where these facilitated comparisons of testing in different settings, different populations or using different sampling methods. RESULTS: 38 studies on SARS-CoV-2 virus testing and 25 studies on SARS-CoV-2 antibody testing were identified. We identified high or unclear risks of bias in the majority of studies, most commonly as a result of unclear methods of patient selection and test conduct, or because of the use of a reference standard that may not definitively diagnose COVID-19. The majority were in hospital settings, in patients with confirmed or suspected COVID-19 infection. Pooled analysis of 16 studies (3818 patients) estimated a sensitivity of 87.8% (95% CI 81.5% to 92.2%) for an initial reverse-transcriptase PCR test. For antibody tests, 10 studies reported diagnostic accuracy outcomes: sensitivity ranged from 18.4% to 96.1% and specificity 88.9% to 100%. However, the lack of a true reference standard for SARS-CoV-2 diagnosis makes it challenging to assess the true diagnostic accuracy of these tests. Eighteen studies reporting different sampling methods suggest that for virus tests, the type of sample obtained/type of tissue sampled could influence test accuracy. Finally, we searched for, but did not identify, any evidence on how any test influences subsequent patient management. CONCLUSIONS: Evidence is rapidly emerging on the effectiveness of tests for COVID-19 diagnosis and management, but important uncertainties about their effectiveness and most appropriate application remain. Estimates of diagnostic accuracy should be interpreted bearing in mind the absence of a definitive reference standard to diagnose or rule out COVID-19 infection. More evidence is needed about the effectiveness of testing outside of hospital settings and in mild or asymptomatic cases. Implementation of public health strategies centred on COVID-19 testing provides opportunities to explore these important areas of research.

A scoping review of patient and public perspectives on cell and gene therapies.

Aim: The development and introduction of cell and gene therapies presents complex social and economic issues. Fully addressing these challenges requires engagement with patients and the public. Materials & methods: A systematically conducted scoping review was undertaken to gauge current patient and public knowledge and perspectives, and as such inform requirements for future research, education and engagement activities. Results: A heterogeneous collection of 35 studies were identified. Levels of knowledge among patients and the public were extremely variable. Studies indicated general acceptance of therapies. Conclusion: The review identified the need for tailored educational activities, and in particular the importance of addressing misconceptions. There is also a need for robust qualitative research considering perspectives on current and forthcoming licensed therapies.

Patient and public perspectives on cell and gene therapies: a systematic review.

Cell and gene therapies offer opportunities for treating disease with potential to restore function, and cure disease. However, they are not without risk and pose complex logistical, economic, ethical and social challenges for health systems. Here we report our systematic review of the current evidence on patient and public knowledge and perspectives of cell and gene therapies, to inform future research, education and awareness raising activities. We screened 10,735 titles and abstracts, and evaluated the full texts of 151 publications. The final selection was 35 publications. Four themes were generated from the narrative synthesis of the study findings namely: (1) Knowledge and understanding of cell and gene therapies, (2) Acceptance of cell and gene therapies (3) Understanding of risk and benefits of therapy, and (4) Information needs and current sources of information. As potential funders or future recipients, it is important that the public and patients are aware of these therapies, understand the issues involved, and can contribute to the debate. This review highlights the need for appropriate patient and public education on the various aspects of cell and gene therapies. High quality studies exploring patient and public opinions and experiences of cell and gene therapy are required. Patient and public perceptions of these therapies, alongside evidence of clinical and cost-effectiveness, will be central to their uptake and use.

Increased frequency of CD4+ PD-1+ HLA-DR+ T cells is associated with disease progression in CLL.

Chronic lymphocytic leukaemia (CLL) patients often have abnormal expansions of CD4+ and CD8+ T cells and this can be associated with progressive disease. To characterise the key T-cell populations involved in this phenomenon, we used flow cytometry and 11 phenotypic markers to study 74 CLL patients and 14 controls. T cells of CLL patients were more phenotypically complex than those of healthy controls with significant increases in the frequencies of CD4 and CD8 memory T cells expressing exhaustion-, activation- and senescence-associated markers. Multivariate analysis of 111 different T-cell subsets showed that high frequencies of four subsets (three CD8 and one CD4) were associated with shorter progression-free survival. The most significant association was with CD4+ HLA-DR+ PD-1+ T cells, and patients could be stratified into high- and low-risk groups based on the frequency of these T cells. The expansion of this CD4+ subset could not be accounted for by age, cytomegalovirus infection or increases in Treg cells. Overall, these results highlight two relatively simple biomarkers, percentage CD8+ and percentage CD4+ PD-1+ HLA-DR+ T cells, which can be used to risk-stratify CLL patients, independent of other tumour-associated markers. They also provide further evidence for the pivotal role of T cells in modulating the pathology of CLL.