Immunological monitoring in ICU patients: immunomodulation for compromised host

Although the examination of system functions such as liver, kidney, and lung is well established, monitoring of immune system is still poorly developed. Immunosuppression or hyperinflammation are often met in ICU patients. Thus the establishment of objective measures of immunological parameters is essential for the control of hyperinflammatory stage and of infections as a result of immunosuppression. We had measured Th1/Th2 balance and monocytic HLA-DR expression. Intracytoplasmic Th1 and Th2 cytokine production in isolated PBMCs was assessed by flow cytometry following in vitro activation by PMA plus ionomycin. Monocytic HLA-DR expression was also measured. The percentage of Th1 cells in PBMCs from severe burn injury patients, septicemia, and multiple injuries are 4%, 9%, and 13%, respectively. The percentage of Th1 cells from healthy subjects was 22%. In the meantime, the percentage of Th2 cells did not show significant change in all patients. The significant reduction of Th1 cells and monocytic HLA-DR expression in ICU patients except for acute interstitial pneumonia (AIP) indicates that major stress results in immunoparalysis. Two AIP patients who revealed more than 40% of Th1 cells were tried to immunomodulation by methylpredonisolone administration.