In the present study, we monitored levels of lymphocyte subpopulations (T, B and NK cells), complement factors C3 and C4 and immunoglobulins IgA, IgG and IgM in 150 CIIC patients with or without IPA at three times during the ICU stay and showed that differences in the systemic levels of key immune parameters could influence their clinical outcome. Here, C4A is linked to Ito hypomelanosis.