[Screening for alpha1-antitrypsin deficiency using dried blood spot: Assessment of the first 20 months]. / Dépistage du déficit en alpha1-antitrypsine sur sang capillaire recueilli sur papier-filtre : bilan des 20 premiers mois.

INTRODUCTION: Alpha1-antitrypsin deficiency is a predisposing factor for pulmonary disease and under-diagnosis is a significant problem. The results of a targeted screening in patients with respiratory symptoms possibly indicative of severe deficiency are reported here. METHODS: Data were collected from March 2016 to October 2017 on patients who had a capillary blood sample collected during a consultation with a pulmonologist and sent to the laboratory for processing to determine alpha1-antitrypsin concentration, phenotype and possibly genotype. RESULTS: In 20 months, 3728 test kits were requested by 566 pulmonologists and 718 (19 %) specimens sent: among these, 708 were analyzable and 613 were accompanied by clinical information. Of the 708 samples, 70 % had no phenotype associated with quantitative alpha1- antitrypsin deficiency, 7 % had a phenotype associated with a severe deficiency and 23 % had a phenotype associated with an intermediate deficiency. One hundred and eight patients carried at least one PI*Z allele which is considered to be a risk factor for liver disease. CONCLUSIONS: The results of this targeted screening program for alpha1- antitrypsin deficiency using a dried capillary blood sample reflect improvement in early diagnosis of this deficiency in lung disease with good adherence of the pulmonologists to this awareness campaign.

High-resolution computed tomography in assessment of patients with emphysema.

OBJECTIVE: To assess whether high-resolution computed tomography (HRCT) variables are as good as other known clinical variables in grading emphysema patients. METHODS: A detailed clinical history was taken and physical examination performed. We performed serum study, lung function testing, and HRCT scanning to assess emphysema. Mean lung density, the attenuation value separating the least 15% of pixels (PERC15), the percentage of the relative area of the lungs with attenuation values < -950 Hounsfield units (HU) (RA950), and histogram analysis were calculated from computerized data. RESULTS: The final analysis was based on data from 92 subjects, and they were moderately emphysematous (mean lung density was -877 ± 23 HU, PERC15 was -953 ± 21 HU, and RA950 was 16 ± 5%). There was a significant difference regarding subjective emphysema severity in the St George's Respiratory Questionnaire, smoking history, FEV1, C-reactive protein, age, and body mass index (P < .001). There was a significant correlation between the 3 objective image variables and the 6 objective clinical variables (St George's Respiratory Questionnaire, smoking history, FEV1, C-reactive protein, age, and body mass index) (P < .001). CONCLUSIONS: This study shows the possible important role of HRCT in the diagnosis and quantification of pulmonary emphysema.

Assessment of regional progression of pulmonary emphysema with CT densitometry.

BACKGROUND: Lung densitometry is an effective method to assess overall progression of emphysema, but generally the location of the progression is not estimated. We hypothesized that progression of emphysema is the result of extension from affected areas toward less affected areas in the lung. To test this hypothesis, a method was developed to assess emphysema severity at different levels in the lungs in order to estimate regional changes. METHODS: Fifty subjects with emphysema due to alpha(1)-antitrypsin deficiency (AATD) [AATD deficiency of phenotype PiZZ (PiZ) group] and 16 subjects with general emphysema (general emphysema without phenotype PiZZ [non-PiZ] group) were scanned with CT at baseline and after 30 months. Densitometry was performed in 12 axial partitions of equal volumes. To indicate predominant location, craniocaudal locality was defined as the slope in the plot of densities against partitions. Regional progression of emphysema was calculated after volume correction, and its slope identifies the area of predominant progression. The hypothesis was tested by investigating the correlation between predominant location and predominant progression. RESULTS: As expected, the PiZ patients showed more basal emphysema than the non-PiZ group (craniocaudal locality, - 40.0 g/L vs - 6.2 g/L). Overall progression rate in PiZ patients was lower than in non-PiZ subjects. A significant correlation was found between craniocaudal locality and progression slope in PiZ subjects (R = 0.566, p < 0.001). In the non-PiZ group, no correlation was found. CONCLUSIONS: In the PiZ group, the more emphysema is distributed basally, the more progression was found in the basal area. This finding suggests that emphysema due to AATD spreads out from affected areas.