Fig. 5: Specific pathogenic markers for distinguishing TB, LUAD and sarcoidosis patients.

a, b Quantitative PCR analysis of CTSK (a) and MMP8 (b) mRNAs in each group as indicated. c Representative images of histologic and immunohistochemical analysis (for Cathepsin K and MMP8) of NC, TB, LUAD and sarcoidosis lung sections (n = 8, 10, 12 and 8, respectively). d, e Quantitative analysis of Cathepsin K (d) and MMP8 (e) immunostaining as in c. f, g Quantitative PCR analysis of BRCA1 (f) and PCNA (g) mRNAs in each group as indicated. h Representative images of histologic and immunohistochemical analysis (for BRCA1 and PCNA) of NC, TB, LUAD and sarcoidosis lung sections (n = 8, 10, 12, and 8, respectively). i, j Quantitative analysis of BRCA1 (i) or PCNA (j) immunostaining as in h. k Redundancy analysis demonstrating the correlations of PLA2G6, PLA2G7, AKR1C1, AKR1C3, LTA4H and PTGER4 with each of the indicated groups. The direction of arrows indicates the positive correlation between gene expression level and samples, and the length of arrows indicates the intensity of the correlation. l Heatmap depicting arachidonic acid metabolism-related six-gene signatures of NC, TB, LUAD and sarcoidosis groups according to qPCR results. The box highlights the cluster of sarcoidosis samples. m Receiver operating characteristic (ROC) analysis for evaluating the diagnostic potential of the above-mentioned 6 genes for sarcoidosis. The area under the ROC curve (AUC) in parentheses represents the accuracy of the individual and combined genes for distinguishing sarcoidosis samples from the other samples. For a, b, f, and g, Box-whisker plot indicates the interquartile range (box), the median value (line within the box) and the maximum and minimum value (whiskers). P > 0.05, not significant (ns); ****P < 0.0001 (mean ± s.e.m. of n = 40, 35, 48, and 21 in NC, TB, LUAD and sarcoidosis groups, respectively, one-way ANOVA). Results are representatives of three independent experiments. For d, e, i, and j, four independent visual fields were examined for quantitative analysis. P > 0.05, not significant (ns); *P < 0.05; ***P < 0.001; ****P < 0.0001 (mean ± s.e.m. of n = 4, one-way ANOVA).