Together with our findings, which documented lower hematic frequencies of naïve CD4 T cells and classical monocytes among non-survivors and a high immune-activation degree within the pulmonary site, these data suggest that in the context of CARDS-related lymphopenia, redistribution to the lung may be more clinically relevant for CD4+ T cells and classical monocytes, whose disfunction could contribute to or accelerate a fatal outcome, while the CD8+ T and NK cells might be more involved in the cytokine-triggered histological local damage, as reflected by the immune activation phenotype. Here, CD4 is linked to lymphopenia.