Abstract Background In various ICU conditions, measurement of diminished expression of human leukocyte antigen-DR on circulating monocytes (mHLA-DR) by flow cytometry appears to be a reliable marker of acquired immunosuppression. Low mHLA-DR is associated with an increased risk of nosocomial infections and mortality. Nevertheless, its use remains somewhat limited and has not been adopted in common medical practice. The main drawback of mHLA-DR measurement is likely related to the use of flow cytometry that is not accessible everywhere on a 24/7 basis. Recently, the Accellix system, a fully automated table top cytometer, was developed for use at bedside or emergency labs. Methods The objective was to assess the performance of the Accellix (beta site evaluation including repeatability and method comparison with reference protocol) for the measurement of mHLA-DR expression. Results Accellix repeatability at low and high expression levels of mHLA-DR was < 10% (i.e., within the range of acceptability for clinical ...