Publications

BACKGROUND

Tuberculosis, caused by the bacterium Mycobacterium tuberculosis, remains a leading cause of infectious disease morbidity and mortality, and is responsible for more than 2 million deaths a year. Reports about extremely drug resistant (XDR) strains have further heightened the sense of urgency for the development of novel strategies to prevent and treat TB. Detailed knowledge of the epitopes recognized by immune responses can aid in vaccine and diagnostics development, and provides important tools for basic research. The analysis of epitope data corresponding to M. tuberculosis can also identify gaps in our knowledge, and suggest potential areas for further research and discovery. The Immune Epitope Database (IEDB) is compiled mainly from literature sources, and describes a broad array of source organisms, including M. tuberculosis and other Mycobacterial species.

DESCRIPTION

A comprehensive analysis of IEDB data regarding the genus Mycobacteria was performed. The distribution of antibody/B cell and T cell epitopes was analyzed in terms of their associated recognition cell type effector function and chemical properties. The various species, strains and proteins which the epitope were derived, were also examined. Additional variables considered were the host in which the epitopes were defined, the specific TB disease state associated with epitope recognition, and the HLA associated with disease susceptibility and endemic regions were also scrutinized. Finally, based on these results, standardized reference datasets of mycobacterial epitopes were generated.

CONCLUSION

All current TB-related epitope data was cataloged for the first time from the published literature. The resulting inventory of more than a thousand different epitopes should prove a useful tool for the broad scientific community. Knowledge gaps specific to TB epitope data were also identified. In summary, few non-peptidic or post-translationally modified epitopes have been defined. Most importantly epitopes have apparently been defined from only 7% of all ORFs, and the top 30 most frequently studied protein antigens contain 65% of the epitopes, leaving the majority of M. tuberculosis genome unexplored. A lack of information related to the specific strains from which epitopes are derived is also evident. Finally, the generation of reference lists of mycobacterial epitopes should also facilitate future vaccine and diagnostic research.

Although the worldwide incidence of HIV infection is high, the retrovirus displays a surprisingly low infectivity in vitro. As a potential explanation for this discrepancy, Münch et al. (2007) now identify and characterize a factor found in human semen that under certain conditions can enhance HIV infectivity by more than 100,000-fold.

BACKGROUND

Symptoms are a central component of health status; however, little is known about the full range and trajectory of symptoms experienced by persons with chronic diseases other than cancer.

METHODS

Observational cohort study with interviews performed at least every 4 months for up to 2 years among community-dwelling persons 60 years or older with chronic obstructive pulmonary disease (COPD) or heart failure (HF). Seven symptoms rated as absent, mild, moderate, or severe were assessed at each interview.

RESULTS

Among the 79 participants with COPD, at least 50% reported shortness of breath, physical discomfort, fatigue, and problems with appetite and anxiety. Among the 59 participants with HF, at least 50% reported physical discomfort, fatigue, and problems with appetite at both their initial and final interviews. Both disease-specific and non-disease-specific symptoms increased in severity over time. The prevalence of individual symptoms did not differ according to whether the participants lived or died.

CONCLUSIONS

As a potentially modifiable contributor to poor health status, the high symptom burden among older persons with COPD and HF represents a large unmet need for improved symptom assessment and treatment. This need may not be met by current disease management guidelines, which focus on a small number of symptoms except for patients at the end of life.

BACKGROUND

The prognostic value of BAL fluid cell count differential in patients with idiopathic pulmonary fibrosis (IPF) is unknown. We hypothesized that baseline BAL fluid cell count differential (ie, elevated levels of neutrophils and eosinophils, or reduced levels of lymphocytes) would predict higher mortality among persons with IPF.

METHODS

We evaluated the association of BAL fluid cell count differential and mortality among 156 persons with surgical lung biopsy-proven IPF who underwent bronchoscopy with BAL and cell count differential measurements at presentation. Vital status was obtained among all participants. Cox regression analysis evaluated the association of BAL fluid cell count differential and mortality.

RESULTS

After controlling for known clinical predictors of mortality, we found that each doubling of baseline BAL fluid neutrophil percentage was associated with a 30% increased risk of mortality (adjusted hazard ratio [HR], 1.28; 95% confidence interval [CI], 1.01 to 1.62; adjusted p = 0.04) in the first year after presentation. We observed no association with BAL fluid lymphocyte percentage and mortality (adjusted HR per doubling, 0.99; 95% CI, 0.76 to 1.29; p = 0.93) or eosinophil percentage and mortality (adjusted HR per doubling, 0.99; 95% CI, 0.69 to 1.40; p = 0.95).

CONCLUSIONS

Increased BAL fluid neutrophil percentage is an independent predictor of early mortality among persons with IPF. Alternatively, BAL fluid lymphocyte and eosinophil percentages were not associated with mortality. The clinical utility of BAL at the time of diagnosis of IPF should be reconsidered.