Incidence of outcomes relevant to vaccine safety monitoring in a US commercially-insured population.

BACKGROUND: Background incidence rates (IRs) of potential safety outcomes among vaccine eligible individuals can inform assessment of vaccine safety. Vaccine safety surveillance often uses claims databases, but the impact of outcome definitions on background IR estimates is largely unexplored. Using two definitions for each outcome, we estimated background IRs of 32 cardiac, metabolic, allergic, autoimmune, neurologic, hematologic and nephrologic outcomes among individuals eligible to receive pneumococcal vaccination. METHODS: We defined a cohort of individuals aged 6-100 years in US commercial health plans who had ≥12 months of health plan enrollment between January 2007 and August 2014 and no previous record of conjugate or simple polysaccharide pneumococcal vaccination. We developed a sensitive and a specific definition for each outcome, with the specific definition requiring evidence of additional care consistent with the outcome. IRs per 100,000 person-years for each outcome were presented overall and stratified by age, gender, and invasive pneumococcal disease (IPD) risk category. RESULTS: We followed 19.9 million individuals for a median of 2.5 years. Wide variation was seen in IRs across different definitions of the 32 outcomes, with 19 (59%) outcomes having a specific definition IR less than half of the sensitive definition IR. IRs were particularly variable by definition for outcomes categorized as either hematologic/nephrologic or neurologic (mean ratio of specific IR to sensitive IR = 0.26 and 0.30, respectively). Across definitions, the IRs of the 32 outcomes were often highest in females, adults ≥65, and those at higher IPD risk. CONCLUSIONS: Background IRs of safety outcomes relevant to populations indicated for pneumococcal vaccine varied by outcome definitions and population subgroups in this large US commercially-insured population. Given large differences in estimated IRs using sensitive versus specific case definitions, neurologic, and hematologic/nephrologic safety outcomes as compared to allergic and autoimmune outcomes may warrant more refined definitions and medical record validation.

Von Willebrand factor is reversibly decreased during torpor in 13-lined ground squirrels.

During torpor in a hibernating mammal, decreased blood flow increases the risk of blood clots such as deep vein thrombi (DVT). In other animal models platelets, neutrophils, monocytes and von Willebrand factor (VWF) have been found in DVT. Previous research has shown that hibernating mammals decrease their levels of platelets and clotting factors VIII (FVIII) and IX (FIX), increasing both bleeding time and activated partial thromboplastin time. In this study, FVIII, FIX and VWF activities and mRNA levels were measured in torpid and non-hibernating ground squirrels (Ictidomys tridecemlineatus). Here, we show that VWF high molecular weight multimers, collagen-binding activity, lung mRNA and promoter activity decrease during torpor. The VWF multimers reappear in plasma within 2 h of arousal in the spring. Similarly, FIX activity and liver mRNA both dropped threefold during torpor. In contrast, FVIII liver mRNA levels increased twofold while its activity dropped threefold, consistent with a post-transcriptional decrease in FVIII stability in the plasma due to decreased VWF levels. Finally, both neutrophils and monocytes are decreased eightfold during torpor which could slow the formation of DVT. In addition to providing insight in how blood clotting can be regulated to allow mammals to survive in extreme environments, hibernating ground squirrels provide an interesting model for studying.

The trans-10, cis-12 isomer of conjugated linoleic acid decreases adiponectin assembly by PPARgamma-dependent and PPARgamma-independent mechanisms.

The adipocyte-derived secretory protein adiponectin functions as an insulin-sensitizing agent. In plasma, adiponectin exists as low, medium, and high molecular weight oligomers. Treatment with trans-10, cis-12 conjugated linoleic acid (t-10, c-12 CLA) reduces levels of adiponectin as well as triglyceride (TG) in mice and adipocyte cell culture models. The aim of this study was to determine whether the effects of t-10, c-12 CLA on adiponectin and TG are mediated through modulation of the transcription factor peroxisome proliferator-activated receptor gamma (PPARgamma). 3T3-L1 cells were treated either during or after differentiation into adipocytes with 100 microM t-10, c-12 CLA with or without 10 microM troglitazone, a PPARgamma agonist, or 1 microM GW9662, a PPARgamma antagonist, and adiponectin and TG levels were analyzed. Treatment with t-10, c-12 CLA reduced TG as well as cellular and secreted adiponectin levels and impaired the assembly of adiponectin oligomers. These changes were accompanied by decreases in PPARgamma mass. Troglitazone was able to reverse the t-10, c-12 CLA-mediated decrease in TG levels and restore the assembly of adiponectin oligomers but was unable to restore adiponectin synthesis. Conversely, treatment with GW9662 decreased TG mass and impaired adiponectin oligomer assembly but did not decrease total adiponectin mass. In a reporter assay, t-10, c-12 CLA appeared to be a partial PPARgamma agonist and prevented the stimulation of reporter activity by troglitazone. Therefore, the t-10, c-12 CLA isomer appears to alter adipocyte adiponectin metabolism through PPARgamma-dependent and PPARgamma-independent mechanisms.