Expression of mRNA levels of HLA-DRA in relation to monocyte HLA-DR: a longitudinal sepsis study
KeywordsFlow Cytometry Hospital Admission Blood Culture Sepsis Severity Longitudinal Data
Decreased monocyte surface HLA-DR (mHLA-DR) measured by flow cytometry (FCM) is an independent marker of immunosuppression in sepsis. In a previous report we demonstrated that septic patients display a strong correlation between mHLA-DR and mRNA-levels of HLA-DRA in whole blood . mRNA-based HLADR monitoring by PCR would improve the clinical usage and facilitate conduction of multicentre studies. The primary focus in this study was to evaluate the correlation between mHLA-DR and HLA-DRA at different time points during sepsis. In addition, we assessed the dynamic expression of both mHLA-DR and HLA-DRA, in relation to sepsis severity.
Study patients (n = 54) were included at day 1 to 2 after hospital admission if blood cultures turned positive. Repeated sampling at days 1 to 2, 3, 7, 14 and 28 was performed. mHLA-DR was monitored by FCM and HLA-DRA by quantitative RT-PCR. Mixed models for longitudinal data were used after logarithmic transformation to calculate the interactional effects of time and severity on HLA-DR expression.
The correlation between flow cytometry and PCR-based HLA-DR monitoring is stronger in the early phase of sepsis. However, the linear associations over time, in relation to sepsis severity, display similar results for both HLA-DR markers. HLA-DRA(PCR) as a biomarker could be an alternative approach in monitoring immune status in sepsis but needs to be evaluated in relation to clinically relevant immunosuppression.
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