Fig. 1

The frequency of Tfh cells and IL-21 producing Tfh cells in patients with acute dengue in the acute phase. The expression of total Tfh cells (cells expressing CD4 + CXCR5+) and IL-21 producing Tfh cells in two patients; patient a with acute dengue infection (day 7 since onset of illness) and patient b with acute dengue infection (day 6 since onset of illness) are shown. The frequency of Tfh cells (c) was assessed in patients with acute DENV2 infection (n = 40), in healthy individuals (n = 12), in patients with DF (n = 18), in patients with DHF (n = 22), in patients with primary infection (n = 13) and secondary dengue infection (n = 27) by multiparametric flowcytometry. The lines display the median and the IQR. **P < 0.01, ***p < 0.001, ****p < 0.0001