Inhaled Corticosteroids in Patients with Chronic Obstructive Pulmonary Disease and Risk of Acquiring Streptococcus pneumoniae Infection. A Multiregional Epidemiological Study.

Background: Inhaled corticosteroids (ICS) are associated with an increased risk of clinical pneumonia among patients with chronic obstructive pulmonary disease (COPD). It is unknown whether the risk of microbiologically verified pneumonia such as pneumococcal pneumonia is increased in ICS users. Methods: The study population consists of all COPD patients followed in outpatient clinics in eastern Denmark during 2010-2017. ICS use was categorized into four categories based on accumulated use. A Cox proportional hazard regression model was used adjusting for age, body mass index, sex, airflow limitation, use of oral corticosteroids, smoking, and year of cohort entry. A propensity score matched analysis was performed for sensitivity analyses. Findings: A total of 21,438 patients were included. Five hundred and eighty-two (2.6%) patients acquired a positive lower airway tract sample with S. pneumoniae during follow-up. In the multivariable analysis ICS-use was associated with a dose-dependent risk of S. pneumoniae as follows: low ICS dose: HR 1.11, 95% CI 0.84 to 1.45, p = 0.5; moderate ICS dose: HR 1.47, 95% CI 1.13 to 1.90, p = 0.004; high ICS dose: HR 1.77, 95% CI 1.38 to 2.29, p < 0.0001, compared to no ICS use. Sensitivity analyses confirmed these results. Interpretation: Use of ICS in patients with severe COPD was associated with an increased and dose-dependent risk of acquiring S. pneumoniae, but only for moderate and high dose. Caution should be taken when administering high dose of ICS to patients with COPD. Low dose of ICS seemed not to carry this risk.

Current status of taxonomic groups of oral streptococci in endocarditis. Can virulence factors discriminate between endocarditis and non-endocarditis strains?

OBJECTIVE: Infective endocarditis is frequently caused by oral streptococci, especially Streptococcus sanguis. In this group, many strains have recently been reclassified on the basis of new taxonomic schemes. The purpose of this study was to classify oral streptococci from patients with infective endocarditis and, further, to assess the importance of specific virulence factors for the development of streptococcal endocarditis. METHODS: Twenty-eight previously identified and 10 new streptococcal isolates from infective endocarditis were classified according to Kilian et al (1989) and compared to 30 streptococcal isolates from the oral cavities of periodontal patients without endocarditis. Subsequently, surface hydrophobicity was assessed by hydrophobic interaction chromatography, production of extracellular dextran was determined by precipitation, and non-specific proteolytic activity was evaluated by determination of hydrolysis of gelatin, and casein-precipitating activity. RESULTS: Eight streptococcal species were represented in the endocarditis isolates. Most strains were highly hydrophobic and none showed non-specific proteolytic activity. Dextran was produced with similar frequency in endocarditis and non-endocarditis isolates. CONCLUSIONS: The present study showed that infective endocarditis may be caused by a variety of oral streptococcal species. The possible virulence factors investigated were found in the same proportions in endocarditis and non-endocarditis isolates, and thus did not seem to be crucial for development of endocarditis.