Association between α1-antitrypsin and bronchiectasis in patients with humoral immunodeficiency receiving gammaglobulin infusions.

BACKGROUND: In patients with humoral immunodeficiency, the progression of bronchiectasis has been known to occur despite adequate gammaglobulin therapy and in the absence of recurrent infections. This observation suggests that factors other than gammaglobulin replacement might play a part in the prevention of lung damage in this population. α1-Antitrypsin deficiency can be associated with bronchiectasis, a chronic inflammatory lung disease. The protective levels of α1-antitrypsin and phenotype in preventing bronchiectasis have not been thoroughly studied in the immunodeficient population. We hypothesized that patients with humoral immunodeficiencies on gammaglobulin infusions and bronchiectasis have lower median levels, but not necessary "classically" deficient levels, of α1-antitrypsin compared with those without bronchiectasis. OBJECTIVE: To compare levels of α1-antitrypsin in subjects with immunodeficiency with and without bronchiectasis. METHODS: One hundred ninety-two subjects with humoral immunodeficiencies requiring gammaglobulin therapy had their α1-antitrypsin levels and phenotype screened. High-resolution computed tomograms of the chest of participants were obtained and compared with α1-antitrypsin levels and phenotype. RESULTS: Participants without bronchiectasis were found to have higher median levels of α1-antitrypsin than those with bronchiectasis (P = .003). Furthermore, subjects with improving or resolved bronchiectasis since initiating gammaglobulin therapy had higher median levels of α1-antitrypsin than those with worsening bronchiectasis (P = .004). The prevalence of the α1-antitrypsin PiZZ mutation was higher than in the general public (P < .0001). CONCLUSION: Median α1-antitrypsin levels and phenotype in subjects were associated with humoral immunodeficiency and their bronchiectasis status. Prospective studies might be necessary to determine possible benefits of augmentation therapy. This study supports the idea that what is considered a "normal or protective" α1-antitrypsin range might need to be refined for patients with humoral immunodeficiency on gammaglobulin therapy.

Versatile inlet system for on-line compound-specific deltaD and delta13C gas chromatography-oxidation/reduction-isotope ratio mass spectrometry analysis of gaseous mixtures.

Compound-specific deltaD and delta13C analyses of gas mixtures are useful indicators of geochemical and environmental factors. However, the relative concentrations of individual components in gas mixtures (e.g., H2, CO2, methane, ethane, propane, i-butane, n-butane) may vary over several orders of magnitude. The determination of hydrogen and carbon compound-specific stable isotope ratios requires that the hydrogen and carbon dioxide produced from each separated component has a concentration adjusted to match the dynamic range of the stable isotope mass spectrometer. We present a custom-built gas sampling and injection system (GASIS) linked with a Delta Plus XP mass spectrometer that provides flexibility, ease of operation, and economical use of small gas samples with wide ranges of analyte concentrations. The overall on-line GC-ox/red-IRMS (Gas Chromatography - oxidation/reduction - Isotope Ratio Mass Spectrometry) system consists of (i) a customized GASIS inlet system and (ii) two alternative reactors, namely an oxidative Cu-Ni-Pt reactor at 950 degrees C for production of CO2 and a reductive graphitized Al2O3 reactor at 1420 degrees C for production of H2. In addition, the system is equipped with (iii) a liquid nitrogen spray-cooling unit for cryo-GC-focusing at -20 degrees C, and (iv) a Nafion dryer for removal of water vapor from product CO2. The three injection loops of the GASIS inlet allow flexibility in the volume of injected analyte gas (e.g., from 0.06 to 500 microL) in order to measure reproducible deltaD and delta13C values for gases at concentrations ranging from 100% down to 10 ppm. We calibrate our GC-ox/red-IRMS system with two isotopically distinct methane references gases that are combusted off-line and characterized using dual-inlet IRMS.