Relationship between the respiratory microbiome and the severity of airflow limitation, history of exacerbations and circulating eosinophils in COPD patients.

BACKGROUND: The respiratory microbiome is altered in COPD patients but its relationship with core components of the disease, such as the severity of airflow limitation, the frequency of exacerbations or the circulating levels of eosinophils, is unclear. METHODS: Cross-sectional study comprising 72 clinically stable COPD patients (mean age 68 [SD 7.9] years; FEV1 48.7 [SD 20.1]% of reference) who provided spontaneous sputum samples for 16S rRNA gene amplification and sequencing. The microbiome composition was analysed with QIIME. RESULTS: We observed that: (1) more severe airflow limitation was associated with reduced relative abundance (RA) of Treponema and an increase in Pseudomonas; (2) patients with ≥2 exacerbations the previous year showed a significantly different bacterial community with respect to non-exacerbators (p = 0.014), with changes in 13 genera, including an increase of Pseudomonas, and finally, (3) peripheral eosinophils levels ≥2% were associated with more diverse microbiome [Chao1 224.51 (74.88) vs 277.39 (78.92) p = 0.006; Shannon 3.94 (1.05) vs 4.54 (1.06) p = 0.020], and a significant increase in the RAs of 20 genera. CONCLUSION: The respiratory microbiome in clinically stable COPD patients varies significantly according to the severity of airflow limitation, previous history of exacerbations and circulating eosinophils levels.

Predictive factors of severe multilobar pneumonia and shock in patients with influenza.

PURPOSE: To identify risk factors present at admission in adult patients hospitalised due to influenza virus infection during the 2009/10 and 2010/11 seasons--including whether infection was from pandemic or seasonal influenza A infections--that were associated with the likelihood of developing severe pneumonia with multilobar involvement and shock. METHODS: Prospective cohort study. Patients hospitalised due to influenza virus infection were recruited. We collected information on sociodemographic characteristics, pre-existing medical conditions, vaccinations, toxic habits, previous medications, exposure to social environments, and EuroQoL-5D (EQ-5D). Severe pneumonia with multilobar involvement and/or shock (SPAS) was the primary outcome of interest. We constructed two multivariate logistic regression models to explain the likelihood of developing SPAS and to create a clinical prediction rule for developing SPAS that includes clinically relevant variables. RESULTS: Laboratory-confirmed A(H1N1)pdm09, EQ-5D utility score 7 days before admission, more than one comorbidity, altered mental status, dyspnoea on arrival, days from onset of symptoms, and influenza season were associated with SPAS. In addition, not being vaccinated against seasonal influenza in the previous year, anaemia, altered mental status, fever and dyspnoea on arrival at hospital, difficulties in performing activities of daily living in the previous 7 days, and days from onset of symptoms to arrival at hospital were related to the likelihood of SPAS (area under the curve value of 0.75; Hosmer-Lemeshow p value of 0.84). CONCLUSIONS: These variables should be taken into account by physicians evaluating a patient affected by influenza as additional information to that provided by the usual risk scores.