Longitudinal follow-up of patients with alpha(1)-protease inhibitor deficiency before and during therapy with IV alpha(1)-protease inhibitor

Abstract

Background: The efficacy of IV augmentation therapy with human alpha(1)-protease inhibitor (alpha(1)-Pi) in patients with severe alpha(1)-Pi deficiency is still under debate.

Study objectives: To evaluate the progression of emphysema in patients with alpha(1)-Pi deficiency before and during a period in which they received treatment with alpha(1)-Pi.

Design: Multicenter, retrospective cohort study.

Setting: Outpatient clinics of 26 university clinics and pulmonary hospitals.

Patients: Ninety-six patients with severe alpha(1)-Pi deficiency receiving weekly augmentation therapy with human alpha(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%, IV alpha(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 alpha(1)-Pi deficiency and well-preserved lung function show a rapid decline in FEV(1). These patients profit from weekly IV therapy with human alpha(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.