In a pilot study, researchers who administered a single dose of humanized anti-human interleuken (IL)-5 antibody to patients with severe, persistent asthma significantly reduced, for up to 30 days, the number of eosinophils in the blood. (The number of these cells characteristically rises during mucosal inflammation underlying allergic disorders.) In addition, the investigators demonstrated a limited short-lived improvement in patient pulmonary function. All participants in the trial were being treated for their disease with either oral or high doses of inhaled steroids. Yet even high doses of inhaled steroids did not significantly reduce peripheral blood eosinophil levels. (Eosinophils, a type of white blood cell, normally constitute from 1 to 3 percent of the total white blood cell count. Elevated levels of activated eosinophils are believed to play a key role in the pathophysiology of asthma and rhinitis.) After administration of the antibody to patients in this pilot study, the researchers observed a trend toward improvement in baseline pulmonary function test scores. In this controlled study, a smaller number of participants received a placebo dose. The investigators said that although circumstantial evidence links IL-5 and eosinophils to the pathophysiology of asthma, this relationship remains unproved. They noted that larger clinical trials to assess the efficacy of anti-IL-5 antibodies should be performed to address many important questions related to points raised by this pilot project. Their research appears in the second issue for June 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
SEVERE ASPIRATION PNEUMONIA MICROORGANISMS COLONIZED IN DENTAL PLAQUE
In research on a group of 95 elderly patients from a nursing home who were hospitalized for severe aspiration pneumonia, investigators concluded that the bacteriology associated with their disease could have sprung from microorganisms that had been colonized in either their dental plaque or oropharyngeal cavity at the time of aspiration. The investigators were looking at the relationship of aspiration pneumonia to oral hygiene by using quantitative bronchial sampling, which they combined with collection of multiple sets of other data. (Aspiration pneumonia consists of inflammation of the lung and bronchi caused by inhaling or choking on vomit. It is the second most frequent principal diagnosis associated with hospitalization of Medicare patients.) The authors said that poor dental health in the nursing home patients due to lack of professional dental care and poor oral hygiene could easily have led to an environment that promoted the colonization of dental plaque by anaerobic and Gram-negative organisms. They added that neither nursing home staff nor physicians appear to give high priority to the oral care of residents. Of the 67 pathogens identified by the investigators, Gram-negative enteric bacilli were the predominant organisms at 49 percent, followed by anaerobic bacteria at 16 percent, and Staphylococcus aureus at 12 percent. According to the authors, the crude mortality rate among the elderly patients studied was 33 percent for the aerobic group. The research is published in the second issue for June 2003 of the American Thoracic Society's peer-reviewed American Journal of Respiratory and Critical Care Medicine.
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Journal
American Journal of Respiratory and Critical Care Medicine