Identification of immunoglobulin E epitopes on major allergens from dairy products after digestion and transportation in vitro.

Dairy processing can alter the digestion stability and bioavailability of cow milk proteins in the gastrointestinal tract. However, analysis of stable linear epitopes on cow milk allergens that could enter into intestinal mucosal is limited. Thus, this study aimed to investigate the digestion and transportation properties and residual allergen epitopes entering into gastrointestinal mucosa of 3 commercial dairy products, including pasteurized milk (PM), ultra-heat-treated milk (UHTM), and dried skim milk (DSM). In this work, the digestive stability of the 3 kinds of dairy products has been performed in a standard multistep static digestion model in vitro and characterized by Tricine-SDS-polyacrylamide gel electrophoresis and reversed-phase HPLC. With respect to gastrointestinal digestion in vitro, the main allergens including ß-lactoglobulin (ß-LG), α-lactalbumin (α-LA), and caseins were degraded gradually, and the resistance peptides remained in the PM with a molecular weight of range from 3.4 to 5.0 kDa. Simultaneously, the potential allergenicity of the cow milk proteins was diminished gradually and is basically consistent after 60 min of gastrointestinal digestion. After gastrointestinal digestion, the remaining peptides were transported via an Ussing chamber and identified by liquid chromatography-MS/MS. By alignment, 10 epitopes peptides were identified from 16 stable peptides, including 5 peptides (AA 92-100, 125-135, 125-138, and 149-162) in ß-LG, 2 peptides in α-LA (AA 80-93 and 63-79), 2 peptides in αS1-casein (AA 84-90 and 125-132), and 1 peptide (AA 25-32) in αS2-casein were identified by dot-blotting mainly exist in UHTM and PM. This study demonstrates dairy processing can affect the digestion and transport characteristics of milk proteins and in turn alter epitope peptides release.

Improvement in clinical and economic outcomes with empiric antibiotic therapy covering atypical pathogens for community-acquired pneumonia patients: a multicenter cohort study.

OBJECTIVE: To determine the effectiveness of empiric antibiotic regimens covering atypical pathogens with respect to detailed clinical and economic outcomes in community-acquired pneumonia (CAP). METHODS: A population-based, multicenter, retrospective cohort study was conducted from June 2010 to May 2011. Patients with a diagnosis of CAP were enrolled and categorized into two groups according to the initial antibiotic strategy used - covering or not covering atypical pathogens. Regression analysis was performed to assess their clinical outcomes (all-cause mortality, clinical improvement rate after 72 h of antimicrobial therapy, and clinical cure rate) and economic outcomes (length of stay, hospitalization costs, and antibiotic expenditure). RESULTS: A total of 827 patients met the criteria for CAP; 561 (67.8%) received antibiotics with atypical pathogen coverage (APC group), while 266 (32.2%) did not (non-APC group). Regression analysis revealed that the all-cause mortality was much lower in the APC group than in the non-APC group (0.9% vs. 4.9%, respectively), with an odds ratio (OR) of 0.18 (95% confidence interval (CI) 0.06-0.49). Clinical improvement at 72 h (87.7% vs. 85.0%, p=0.274) and the clinical cure rate (91.1% vs. 88.3%, p=0.213) were more favorable in the APC group, but with no significant difference compared to the non-APC group. Moreover, the APC group had a shorter mean length of stay (APC 10.2 days vs. non-APC 11.6 days, p<0.001). In addition, the mean total hospitalization costs for the APC group were markedly lower compared with the non-APC group (US$ 1172.7 vs. US$ 1510.7; p<0.001). CONCLUSION: Antimicrobial treatment covering atypical pathogens for hospitalized CAP patients is associated with reduced mortality and economic burden.