Demographic and genotypic characteristics of subjects from the Alpha-1 Foundation DNA and Tissue Bank and the Lung Health Study.

<p>*Mean ± standard error of the mean.</p

Log₁₀ of telomere length in α₁-antitrypsin deficient COPD patients vs. log₁₀ of telomere length in COPD controls.

<p>Log₁₀ of telomere length in α₁-antitrypsin deficient COPD patients vs. log₁₀ of telomere length in COPD controls.</p

Log₁₀ of telomere length in the lung vs. log₁₀ of telomere length in the blood.

<p>Log₁₀ of telomere length in the lung vs. log₁₀ of telomere length in the blood.</p

Mean log₁₀ of telomere length in the blood and lung tissue.

<p>Mean log₁₀ of telomere length in the blood and lung tissue.</p

Comparison of the normalized relative expression levels of housekeeping genes (HKGs) between the three subgroups.

<p>The relative expression levels of remaining seven genes were normalized against the Normalization Factor based on the geometric mean of the expression level of the best-performing HKGs (<i>B2M</i> and <i>RPLP0</i>). Data are presented as mean ± SE. ^a<i>P</i><0.05.</p

Flow cytometry analysis on CD4⁺ T cells in lymphocyte suspension and in purified CD4⁺ cells by immunomagnetic depletion with the human CD4⁺ T Cell Isolation Kit II.

<p>Cells were directly stained with conjugated fluorescently labeled antibodies for CD4 (BD Biosciences) in lymphocyte suspension and in purified CD4⁺ samples.</p

Determination of the housekeeping gene expression stability by NormFinder.

<p>The stability value is estimated using the model-based approach. Having considered both the intra- and inter-group variation, a lower stability value represents a smaller systematic error that would be introduced when using the studied gene.</p

Ranking the housekeeping genes (HKGs) according to their expression stability M determined using geNorm.

<p>A stepwise exclusion of the least stable HKG was conducted to obtain the mean expression stability value M of remaining HKGs until the two most stable HKGs were identified. The genes are ranked according to M values.</p

Correlation analysis of candidate housekeeping genes (HKGs) versus BestKeeper index.

<p>^aAll 8 candidate HKGs showed strong correlation (correlation coefficient <i>r</i> value from 0.69 to 0.93) and were combined into an index, which was then used to compute the correlation between each HKG and the index.</p

Data of candidate housekeeping genes (n = 28).

<p>GM, geometric mean; AM, arithmetic mean; Min, minimal value; Max, maximal value; CV, coefficient of variance.</p