Fig. 4

Cellular phenotype and function in case and control infants from cluster 1 and cluster 2. Samples from the primary cohort were analyzed. a Frequencies of monocytes and T cells, measured by flow cytometry (Additional file 1: Figure S6) in unstimulated PBMC from infants in cluster 1 (blue circles, n = 23) and cluster 2 (green circles, n = 18). b Comparison of the cellular phenotype of definite TB case infants from cluster 1 (red closed circles, n = 15) and from cluster 2 (red open circles, n = 10) with that of pooled household controls (black closed circles for cluster 1, n = 8, and black open circles for cluster 2, n = 8). CD14+ monocytes, CD3+ T cells and the ratio of monocytes divided by lymphocytes are shown. c Frequencies of CD4+ T cells expressing either IFN-γ, IL-2 or TNF-α, or all three cytokines together, measured by intracellular cytokine staining and flow cytometry, following whole blood stimulation with BCG for 12 h. For this analysis, definite TB case infants from cluster 1 (red closed circles, n = 12) and from cluster 2 (red open circles, n = 7) were compared to pooled household controls (black closed circles for cluster 1, n = 5, and black open circles for cluster 2, n = 8). Bars depict medians and IQR; the Mann–Whitney U test was used to assess differences in all analyses