Background

From March 2006 to October 2010, 140 patients with alpha-1 antitrypsin (AAT) deficiency who received either intravenous AAT augmentation or placebo in the RAPID study were included in an open-label extension trial (RAPID-OLE). AAT was shown to significantly slow the rate of computed tomography (CT) lung density loss; no differences were noted in spirometry, diffusion capacity (DLCO), or quality of life (QoL). Patients in the Irish RAPID-OLE cohort continued AAT augmentation for the ensuing 12 years.

Aims and objectives

To determine long-term benefits of augmentation therapy.

Methods

We compared augmented patients from RAPID-OLE to non-augmented control Pi*ZZ patients over the same period. Patients were matched for spirometric, demographic, and smoking characteristics. Evaluations included pulmonary function testing (PFT) and QoL. PFT data was obtained at different timepoints between groups.

Results

The duration of follow-up ranged from 1.2?12.1 and 6?13 years for augmented and control subjects (both n=19), respectively. The mean treatment duration for augmented patients was 10.8 years. Mean annual decline in forced expiratory volume (FEV₁) and DLCO% was not significantly different between augmented and control individuals: 38.2 vs. 55.9 ml (p=0.17) and 1.2 vs. 1.3% (p=0.51), respectively. Mean FEV₁% declined in augmented and control patients (5.4 vs. 8.4%), as did DLCO% (7.6 vs. 13.9%).

Conclusions

This spirometry data is consistent with RAPID-OLE. CT is being performed to assess lung density changes from the end of RAPID-OLE and establish if the diminished rate of lung density decline is maintained or whether a plateau has been reached.