In this Letter, we determined changes in peripheral NK cell percentages in progressors - transitioning from LTBI to active disease at different time intervals prior to TB diagnosis, and non- progressors - at different time points over a span of two years, using cell-mixture deconvolution analysis of the gene expression dataset GSE79362 (Fig. 4b (left)). We found that data points from 2 out of the 17 progressors were inadvertently binned into the wrong time intervals. We have now re-analyzed the entire dataset with all data points binned correctly with respect to the time intervals before TB diagnosis. In this revised analysis, the time intervals are set at >400, 201–400, 101–200, 0–100 days before TB diagnosis. The comparisons between NK cell levels a year preceding TB diagnosis to TB diagnosis and ~seven months preceding TB diagnosis to TB diagnosis remain statistically significant, P=0.0312 and P=0.0039 respectively. The original observation of a significant decrease in NK cell percentage during progression to active TB, remains unchanged.
In the original analysis, all non-progressors that had measurements for at least 3 time points were included. We have now included all non-progressors that had longitudinal measurements for at least 2 time points, n=41 (Reporting summary has been updated accordingly). This revised analysis, shows no significant change in NK cell frequencies (P=0.8828) during the two-year study period. The original P value reported was 0.5202.
The ROC curve for the predictive potential of NK cells in discriminating progressors from non- progressors (Fig. 4c) was accordingly recalculated. The new analysis showed an AUC of 0.74 (confidence interval 0.58–0.90) in the three months preceding TB diagnosis, and 0.69 (confidence interval 0.57–0.82) in the seven months preceding TB diagnosis.
These analyses do not change any of our conclusions in the original Letter.
Additionally, in the Author list, the name “Qiantian Yang” should have been spelled as “Qianting Yang”, and the affiliation of the author, Stephanus T. Malherbe, should only be “Department of Science and Technology, National Research Foundation Centre of Excellence for Biomedical Tuberculosis Research, Stellenbosch University, Stellenbosch, South Africa”, and should not include “Catalysis Foundation for Health, Emeryville, CA, USA”, as was originally listed.