Monocytic Human Leukocyte Antigen-DR Expression Levels to Predict Outcome in Children With Severe Sepsis.

OBJECTIVE: To assess the association between monocytic Human Leukocyte Antigen-DR (mHLA-DR)expression and outcome in children with severe sepsis.

METHODS: Consecutive children, aged 29 days to 15 years, who were admitted with severe sepsis or septic shock in the pediatric intensive care unit (PICU) were enrolled. mHLA-DR expression (antigen bound per cell (ABC)) was assessed on two time points: between 72 to 120 hours (P1) and 121 to 168 hours (P2), of stay in PICU and the difference between the two was calculated as delta mHLA-DR. Outcomes were noted for survival, mortality and secondary infection during the hospital stay.

RESULTS: Forty-seven children with median (IQR) age 24 (10, 96) months and a median (IQR) and duration of illness of 3 (3, 5) days, were enrolled consecutively. Pediatric Logistic Organ Dysfunction (PELOD) score >10 was observed in 63.8% children. 18 children succumbed. The median mHLA-DR levels (ABC) at P1 were significantly higher in children who survived as compared with those who expired (7409 vs. 2509, P = 0.004). Similarly, the median mHLA-DR levels (ABC) at P2 were higher in those who survived than the expired group (14728 vs. 2085, P = 0.001). The median delta mHLA-DR levels (ABC) were 4574 and 309 for the survived and expired group, respectively (P = 0.012). mHLA-DR at 72 to 120 hrs (P = 0.004), mHLA-DR at 121 to 168 hrs (P = 0.001) and delta mHLA-DR (P = 0.012) was significantly associated with mortality but not associated with secondary infection. A negative correlation was observed between PELOD score and mHLA-DR at P1 (r = -0.25, P = 0.46), at P2 (r = -0.425, P = 0.018) and delta mHLA-DR (r = -0.27, P = 0.41). The area under curve (95%CI) of mHLA-DR expression (ABC) at P2 for a cutoff of < 6631 was 0.966 (0.907, 1.0) to predict mortality in severe sepsis.

CONCLUSION: mHLA-DR levels were significantly lower in children who succumbed than those who survived at both time points. mHLA-DR levels can be a useful biomarker to diagnose immune-paralysed state.