Longitudinal Follow-up of Patients With α1-Protease Inhibitor Deficiency Before and During Therapy With IV α1-Protease Inhibitor

Background: The efficacy of IV augmentation therapy with human α 1 -protease inhibitor (α 1 -Pi) in patients with severe α 1 -Pi deficiency is still under debate. Study objectives: To evaluate the progression of emphysema in patients with α 1 -Pi deficiency before and during a period in which they received treatment withα 1 -Pi. Design: Multicenter, retrospective cohort study. Setting: Outpatient clinics of 26 university clinics and pulmonary hospitals. Patients: Ninety-six patients with severeα 1 -Pi deficiency receiving weekly augmentation therapy with human α 1 -Pi, 60 mg/kg of body weight, had a minimum of two lung function measurements before and two lung function measurements after augmentation therapy was started. Lung function data were followed up for a minimum of 12 months both before and during treatment (mean, 47.5 months and 50.2 months, respectively). Measurements and results: Patients were grouped according to the severity of their lung function impairment. The change in FEV 1 was compared during nontreatment and treatment periods. In the whole group, the decline in FEV 1 was significantly lower during the treatment period (49.2 mL/yr vs 34.2 mL/yr, p = 0.019). In patients with FEV 1 > 65%, IVα 1 -Pi treatment reduced the decline in FEV 1 by 73.6 mL/yr (p = 0.045). Seven individuals had a rapid decline of FEV 1 before treatment, and the loss in FEV 1 could be reduced from 256 mL/yr to 53 mL/yr (p = 0.001). Conclusion: Some patients with severe α 1 -Pi deficiency and well-preserved lung function show a rapid decline in FEV 1 . These patients profit from weekly IV therapy with human α 1 -Pi and have less rapid decline if treated. Early detection of patients at risk and early start of augmentation therapy may prevent accelerated loss of lung tissue.