67 CF patients with a declining FEV(1): At risk for acquisition of Burkholderia cepacia complex infection?

INTRODUCTION: Burkholderia cepacia complex (Bcc) infection is considered to be associated with worsening of CF lung disease. Patient to patient spread has been reported, however mechanisms of acquisition of Bcc are not well understood. Method: Data from the Belgian CF Registry (year 2000–2010) were collected. Inclusions: Bcc infected patients with entries on lung function in at least 1 y before and 3 y after Bcc acquisition. For each case, we included 2 controls, matched for age at the index year (year of first Bcc infection), pancreatic status, sex. Cumulative data up to 2 years before index year were compared to values obtained after infection using Rank sum test. Rate of decline in lung function was adjusted for baseline lung function, age, sex. RESULTS: Bcc prevalence in CF is low in Belgium (<3%). 183 patients were included: 61 cases, 122 controls. 59% were F508del homozygous. Mean age in cases was 20.9 y (SD 10.5) vs 20.3 y (SD 10.3) in controls. Among the Bcc, 54% were unspecified, 31% were B. multivorans. Mean FEV(1) at index year was 65.2% (SD 24.9) in cases vs 73.1 (SD 26.9) in controls (p = 0.07). FEV(1) decline before index year was significantly higher in cases (–1.7%, SD 0.5) compared to controls (–1.0%, SD 0.3) (p = 0.002). FEV(1) slopes were comparable in the period after index year (–1.1%, SD 0.5, in cases vs –0.99%, SD 0.4, p = 0.24). CONCLUSION: Our results suggest that a declining FEV(1) precedes acquisition of Bcc and may be a risk factor. After acquisition, lung function decline was comparable in Bcc infected and uninfected patients. These results should be interpreted with caution, since registry data are collected retrospectively and bear a risk of incompleteness or inaccuracy.