Introduction: Many studies have shown that monocyte human leukocyte antigen-DR (mHLA-DR) expression may be a good predictor for mortality in severe septic patients. On the contrary, other studies found mHLA-DR was not a useful prognostic marker in severe sepsis. Few studies have taken changes of mHLA-DR during treatment into consideration. The objective of this study was to estimate the prognostic value of changes of mHLA-DR to predict mortality in severe sepsis.
Methods: In this prospective observational study, mHLA-DR was measured by flow cytometry in peripheral blood from 79 adult patients with severe sepsis. mHLA-DR levels were determined on day 0, 3, 7 after admission to the surgical intensive care unit (SICU) with a diagnosis of severe sepsis. ΔmHLA-DR₃ and ΔmHLA-DR₇ were defined as the changes in mHLA-DR value on day 3 and day 7 compared to that on day 0. Data were compared between 28-day survivors and non-survivors. Receiver operating characteristic (ROC) curves were plotted to measure the performance and discriminating threshold of ΔmHLA-DR₃, ΔmHLA-DR₇, ΔmHLA-DR₇-₃, mHLA-DR₀, mHLA-DR₃ and mHLA-DR₇ in predicting mortality of severe sepsis.
Results: ROC curve analysis showed that ΔmHLA-DR₃ and ΔmHLA-DR7 were reliable indicators of mortality in severe sepsis. A ΔmHLA-DR₃ value of 4.8% allowed discrimination between survivors and non-survivors with a sensitivity of 89.0% and a specificity of 93.7%; similarly, ΔmHLA-DR₇ value of 9% allowed discrimination between survivors and non-survivors with a sensitivity of 85.7% and a specificity of 90.0%. Patients with ΔmHLA-DR₃ ≤ 4.8% had higher mortality than those with ΔmHLA-DR₃ > 4.8% (71.4% vs. 2.0%, OR 125.00, 95% CI 13.93 to 1121.67); patients with ΔmHLA-DR7 ≤ 9% had higher mortality than those with ΔmHLA-DR₇ > 9% (52.9% vs. 2.0%, OR 54.00, 95% CI 5.99 to 486.08). The mean change of mHLA-DR significantly increased in the survivor group with the passage of time; from day 0 to day 3 and day 7, changes were 6.45 and 16.90 (P < 0.05), respectively.
Conclusions: The change of mHLA-DR over time may be a reliable predictor for mortality in patients with severe sepsis.