Statistical analysis
Data were analyzed using STATISTICA 13.1 (SatSoft, Kraków, Poland) and
Medcalc 19.1 (MedCalc Software, Ostend, Belgium). Figures were prepared
in GraphPad Prism version 8 (GraphPad Software, San Diego, CA). Data
were presented as medians and interquartile ranges (IQR). We performed
chi-square test or Fisher’s exact test for qualitative variables, and
Kruskall-Wallis test or Mann Whitney test for quantitative variables.
Changes in IFN-γ and IP-10 concentrations during treatment were assessed
using Wilcoxon signed rank test. The Spearman’s rank test was applied to
assess biomarker correlation. The diagnostic performance of IP-10 was
assessed using the receiver operating characteristic curve (ROC)
analysis and the area under the curve (AUC). The highest values of the
Youden’s Index were used for selecting the cut-off values. The TB
antigen and mitogen control concentrations of IP-10 were
background-corrected by subtracting the concentration in the negative
control tube. All tests were two-sided, and a p value of <0.05
was considered significant.
RESULTS: