Lopez-Acevo CA, Arrendondo-Loza E, Salinas-Carmona MC, et al. - In view of the reported correlation of cortisol and stress with respiratory infection susceptibility and cytokine regulation, researchers here investigated patients infected with Influenza B virus (IBV) for systemic cytokines and cortisol, as well as for perceived stress and blood cell count. IBV infected patients showed higher Th1, Th17, and IL-10 cytokines. Viral load was noted to be negatively linked with leukocytes and neutrophil count. IBV infected patients had a negative effect of perceived stress on monocytes and systemic cytokines. They had higher cortisol that correlated positively with CCL20. A positive effect of cortisol on most of the systemic cytokines was evident. In conclusion, IBV infected patients exhibit a cytokine pattern and there is a possible role of leukocyte counts in the control of IBV. Overall, cortisol and perceived stress are suggested to have significant effect on systemic cytokines in patients infected with IBV.