HIV infection is associated with elevated expression of IL-10 and PD-L1, contributing to impairment of T cell effector functions. In autoimmunity, tumor immunology, and some viral infections, Bregs modulate T cell function via IL-10 production. In this study, we tested the hypothesis that during HIV infection, Bregs attenuate CD8(+) T cell effector function, contributing to immune dysfunction. We determined that in vitro, TLR2-, TLR9-, and CD40L-costimulated Bregs from HIV(-) individuals exhibited a high frequency of cells expressing IL-10 and PD-L1. Compared with Bregs from HIV(-) individuals, a significantly higher percentage of Bregs from HIV(+) individuals spontaneously expressed IL-10 (P=0.0218). After in vitro stimulation with HIV peptides, Breg-depleted PBMCs from HIV(+) individuals exhibited a heightened frequency of cytotoxic (CD107a(+); P=0.0171) and HIV-specific CD8(+) T cells compared with total PBMCs. Furthermore, Breg depletion led to enhanced proliferation of total CD8(+) and CD107a(+)CD8(+) T cells (P=0.0280, and P=0.0102, respectively). In addition, augmented CD8(+) T cell effector function in vitro was reflected in a 67% increased clearance of infected CD4(+) T cells. The observed Breg suppression of CD8(+) T cell proliferation was IL-10-dependent. In HIV(+) individuals, Breg frequency correlated positively with viral load (r=0.4324; P=0.0095), immune activation (r=0.5978; P=0.0005), and CD8(+) T cell exhaustion (CD8(+)PD-1(+); r=0.5893; P=0.0101). Finally, the frequency of PD-L1-expressing Bregs correlated positively with CD8(+)PD-1(+) T cells (r=0.4791; P=0.0443). Our data indicate that Bregs contribute to HIV-infection associated immune dysfunction by T cell impairment, via IL-10 and possibly PD-L1 expression.

The diagnostic potential and health implications of volatile organic compounds (VOCs) present in human feces has begun to receive considerable attention. Headspace solid-phase microextraction (SPME) has greatly facilitated the isolation and analysis of VOCs from human feces. Pioneering human fecal VOC metabolomic investigations have utilized a single SPME fiber type for analyte extraction and analysis. However, we hypothesized that the multifarious nature of metabolites present in human feces dictates the use of several diverse SPME fiber coatings for more comprehensive metabolomic coverage. We report here an evaluation of eight different commercially available SPME fibers, in combination with both GC-MS and GC-FID, and identify the 50/30 µm CAR-DVB-PDMS, 85 µm CAR-PDMS, 65 µm DVB-PDMS, 7 µm PDMS, and 60 µm PEG SPME fibers as a minimal set of fibers appropriate for human fecal VOC metabolomics, collectively isolating approximately 90% of the total metabolites obtained when using all eight fibers. We also evaluate the effect of extraction duration on metabolite isolation and illustrate that ex vivo enteric microbial fermentation has no effect on metabolite composition during prolonged extractions if the SPME is performed as described herein.

We describe quality improvement and practice-based research using the electronic medical record (EMR) in a community health system–based department of neurology. Our care transformation initiative targets 10 neurologic disorders (brain tumors, epilepsy, migraine, memory disorders, mild traumatic brain injury, multiple sclerosis, neuropathy, Parkinson disease, restless legs syndrome, and stroke) and brain health (risk assessments and interventions to prevent Alzheimer disease and related disorders in targeted populations). Our informatics methods include building and implementing structured clinical documentation support tools in the EMR; electronic data capture; enrollment, data quality, and descriptive reports; quality improvement projects; clinical decision support tools; subgroup-based adaptive assignments and pragmatic trials; and DNA biobanking. We are sharing EMR tools and deidentified data with other departments toward the creation of a Neurology Practice-Based Research Network. We discuss practical points to assist other clinical practices to make quality improvements and practice-based research in neurology using the EMR a reality.

No abstract

e16552 Background: D has a known single-agent activity in advanced EOC with the response rate of at least 10%. I is a multi-targeted tyrosine kinase inhibitor shown in preclinical studies to decrease interstitial pressure in the tumor and facilitate influx of chemotherapeutic agents into the tumor. Methods: A single-institution trial was conducted in pts with advanced EOC in 2005–2007. The primary endpoint of the study was to determine a tumor response to the study combination. Pts were required to have received 1 or 2 prior chemotherapeutic regimens including a platinum compound and have performance status 0–2. Pts were to receive D 60 mg/m2 IV every 3 weeks and I 400 mg/day by mouth continuously. Planned target accrual for the first stage of the study was 15 pts with the preset minimum of 3 responses to proceed to the second stage. Tumor response was evaluated by RECIST criteria after every 3 cycles of D. Treatment was continued until disease progression or unacceptable toxicity. Results: Study was terminated early due to lack of response and significant toxicities. A total of 10 pts were enrolled. The age range of the pts was 55–79 with the mean age = 64. Five pts were evaluable for response and in all of them, cancer progression was observed after 3 cycles of combination therapy (0 responses). Five pts were taken off the study after 1 cycle of treatment either due to serious adverse events (SAEs) or disease progression. Among grade 3 and 4 SAE's observed in the study were 4 cases of hematological toxicity, 1 case of rash, 1 case of dizziness, and 1 case of deep venous thrombosis. The median progression-free survival for pts on the study was 7.5 weeks. Conclusions: Although the sample size of this study was small, the combination of I and D at the above doses appears ineffective in the population of moderately-pretreated women with advanced EOC. The majority of grade 3 and 4 SAE's were due to myelosuppression likely caused by D rather than I. No significant financial relationships to disclose.