Figure 4.

Evaluation of peripheral blood monocyte population magnitude in relation to severity of illness. A, Representative flow cytometry plots demonstrating increased inflammatory monocyte population (CD14⁺⁺CD16⁺) in infected individuals and selective depletion of this population in infected individuals with very severe illness requiring mechanical ventilation. B, Absolute monocyte and monocyte subpopulation cell numbers in the EDFLU cohort (n = 10 uninfected, n = 6 not severe infected, n = 15 severe infected, n = 3 very severe infected). *P < .05; †P < .005. The open data point with the enclosed X denotes the single fatal case of severe influenza infection. C, The 2009 pandemic H1N1 subjects with severe and very severe illness admitted to the intensive care unit of the National Institute of Respiratory Diseases in Mexico City. Absolute cell count information for these samples was unavailable; therefore, frequency of live CD45⁺ peripheral blood mononuclear cells (PBMCs) are reported. Numbers are percentage of cells present in the gate that is drawn.