Inflammatory changes, recovery and recurrence at COPD exacerbation.

Chronic obstructive pulmonary disease (COPD) exacerbations are associated with increased airway and systemic inflammation, though relationships between exacerbation recovery, recurrent exacerbation and inflammation have not been previously reported. In the present study, inflammatory changes at COPD exacerbations were related to clinical nonrecovery and recurrent exacerbations within 50 days. Serum interleukin (IL)-6, C-reactive protein (CRP), sputum IL-6 and IL-8 were measured in 73 COPD patients when stable, at exacerbation and at 7, 14 and 35 days post-exacerbation. In 23% of patients, symptoms did not recover to baseline by day 35. These patients had persistently higher levels of serum CRP during the recovery period. A total of 22% of the patients who had recurrent exacerbations within 50 days had significantly higher levels of serum CRP at day 14, compared with those without recurrences: 8.8 mg.L(-1) versus 3.4 mg.L(-1). Frequent exacerbators had a smaller reduction in systemic inflammation between exacerbation onset and day 35 compared with infrequent exacerbators. Nonrecovery of symptoms at chronic obstructive pulmonary disease exacerbation is associated with persistently heightened systemic inflammation. The time course of systemic inflammation following exacerbation is different between frequent and infrequent exacerbators. A high serum C-reactive protein concentration 14 days after an index exacerbation may be used as a predictor of recurrent exacerbations within 50 days.

Epidemiological relationships between the common cold and exacerbation frequency in COPD.

Higher exacerbation incidence rates in chronic obstructive pulmonary disease (COPD) are associated with more rapid decline in lung function and poorer quality of life, yet the mechanisms determining susceptibility to exacerbation remain ill-defined. The same viruses responsible for common colds are frequently isolated during exacerbations. The current authors hypothesised that exacerbation frequency may be associated with an increased frequency of colds, and investigated whether increased exacerbation frequency was associated with increased acquisition of colds, or a greater likelihood of exacerbation once a cold has been acquired. A total of 150 patients with COPD completed diary cards recording peak expiratory flow, and respiratory and coryzal symptoms for a median 1,047 days. Annual cold and exacerbation incidence rates (cold and exacerbation frequency) were calculated, and the relationships between these variables were investigated. This analysis is based on 1,005 colds and 1,493 exacerbations. Frequent exacerbators (i.e. those whose exacerbation frequency was greater than the median) experienced significantly more colds than infrequent exacerbators (1.73 versus 0.94.yr(-1)). The likelihood of exacerbation during a cold was unaffected by exacerbation frequency. Patients experiencing frequent colds had a significantly higher exposure to cigarette smoke (46 versus 33 pack-yrs). Exacerbation frequency in chronic obstructive pulmonary disease is associated with an increased frequency of acquiring the common cold, rather than an increased propensity to exacerbation once a cold has been acquired.