Continuous venovenous hemofiltration: effects on monocyte and lymphocyte immunophenotype in critically ill patients

The aim of this study was to test the hypothesis that continuous venovenous hemofiltration (CVVH) increases HLA-DR expression on monocytes and T lymphocytes in critically ill patients. 24 septic (SP) and 10 non-septic (NSP) medical ICU patients with acute renal failure were studied prospectively. The ultrafiltration rate was 20-30 ml.kg(-1).h(-1). The total and differential white cell counts were measured and CD3+ lymphocyte count, HLA-DR expression on CD14+ monocytes and CD3+ lymphocytes were analysed by two-colour flow cytometry before, 4 and 24 h after CVVH initiation, respectively. CVVH did not influence leukocyte, granulocyte, total lymphocyte and CD3+ lymphocyte counts in both groups of patients. The percentage of HLA-DR+/CD14+ monocytes in SP revealed no changes, whereas it decreased after 4 h of CWH in NSP (p < 0.05). The percentage of HLA-DR+/CD3+ lymphocytes in SP decreased after 24 h (p < 0.05), whereas it remained unchanged in NSP. We conclude that CWH initiation is not associated with the increase of HLA-DR expression on CD14+ monocytes and T lymphocytes in critically ill patients with acute renal failure.