Figure 2

Comparison of plasma anti-GPL-core IgA and IgA2 levels among sample groups. Plasma samples from patients with NTM-PD, MTB-PD, and Oth-PD and HCs were quantified for anti-GPL-core antibodies using indirect ELISA. The concentration of anti-GPL-core IgA (A) or IgA2 (B) antibody isotypes is shown with a line representing the median and interquartile range. Statistical differences among sample groups were tested using the Kruskal–Wallis test, and only significant P-values are shown in the figure. Black dashed lines represent the cut-off values of 1.4 U/ml for IgA and 1.0 U/ml for IgA2. Correlation analysis between log₁₀-transformed plasma anti-GPL-core IgA and IgA2 in patients with NTM-PD (C) or dNTM (D) was performed using linear regression. Plasma anti-GPL-core IgA (E) or IgA2 (F) antibody levels from patients with dNTM are plotted with lines connecting samples from the same patients. Antibody levels from the first sample with culture positive (1) were compared to those from the second (2) and third year of follow-up (3). Statistical significance of the decreasing antibody levels was tested using a one-tailed paired t-test, and only significant P-values are shown in the figure.