Publications

Infection with M. tuberculosis is associated with inconsistent and incomplete elimination of the bacteria, despite development of antigen-specific T cell responses. One mechanism employed by M. tuberculosis is to limit availability of antigen for activation of CD4 T cells. We examined the utility of systemic administration of epitope peptides to activate pre-existing T cells in mice infected with M. tuberculosis. We found that systemic peptide administration: 1) selectively activates T cells specific for the epitope peptide; 2) loads MHC class II on lung macrophages and dendritic cells; 3) activates CD4 T cells in the lung parenchyma; 4) has little antimycobacterial activity. Further studies revealed that CD4 T cells in lung lesions are distant from the infected cells, suggesting that, even if they can be activated, the positioning of CD4 T cells and their direct interactions with infected cells may be limiting determinants of immunity in TB.

Antigen-specific CD4 and CD8 T cells are important components of the immune response to , yet little information is currently known regarding how the breadth, specificity, phenotype, and function of -specific T cells correlate with infection outcome in humans. To facilitate evaluation of human -specific T cell responses targeting multiple different Ags, we sought to develop a high throughput and reproducible T cell response spectrum assay requiring low blood sample volumes. We describe here the optimization and standardization of a microtiter plate-based, diluted whole blood stimulation assay utilizing overlapping peptide pools corresponding to a functionally diverse panel of 60 Ags. Using IFN-γ production as a readout of Ag specificity, the assay can be conducted using 50 μl of blood per test condition and can be expanded to accommodate additional Ags. We evaluated the intra- and interassay variability, and implemented testing of the assay in diverse cohorts of -unexposed healthy adults, foreign-born adults with latent infection residing in the United States, and tuberculosis household contacts with latent infection in a tuberculosis-endemic setting in Kenya. The -specific T cell response spectrum assay further enhances the immunological toolkit available for evaluating -specific T cell responses across different states of infection, and can be readily implemented in resource-limited settings. Moreover, application of the assay to longitudinal cohorts will facilitate evaluation of treatment- or vaccine-induced changes in the breadth and specificity of Ag-specific T cell responses, as well as identification of -specific T cell responses associated with infection outcomes.

OBJECTIVE

The aim of the study was to develop standards for tracking patient safety gaps in ambulatory care in safety net health systems.

METHODS

Leaders from five California safety net health systems were invited to participate in a modified Delphi process sponsored by the Safety Promotion Action Research and Knowledge Network (SPARKNet) and the California Safety Net Institute in 2016. During each of the three Delphi rounds, the feasibility and validity of 13 proposed patient safety measures were discussed and prioritized. Surveys and transcripts from the meetings were analyzed to understand the decision-making process.

RESULTS

The Delphi process included eight panelists. Consensus was reached to adopt 9 of 13 proposed measures. All 9 measures were unanimously considered valid, but concern was expressed about the feasibility of implementing several of the measures.

CONCLUSIONS

Although safety net health systems face high barriers to standardized measurement, our study demonstrates that consensus can be reached on acceptable and feasible methods for tracking patient safety gaps in safety net health systems. If accompanied by the active participation key stakeholder groups, including patients, clinicians, staff, data system professionals, and health system leaders, the consensus measures reported here represent one step toward improving ambulatory patient safety in safety net health systems.