Prognostic Significance of Immune Abnormalities in Children with Severe Sepsis.

OBJECTIVES

To evaluate the immunoglobulin levels and lymphocyte subsets in children with severe sepsis at admission to the pediatric intensive care unit (PICU) and correlate them to mortality.

METHODS

A prospective study was conducted on 52 children with severe sepsis/septic shock. Serum immunoglobulins and lymphocyte subsets were measured at diagnosis in all patients and after 3 mo in survivors. Regression analysis was used to identify factors associated with mortality.

RESULTS

The median (interquartile range, IQR) age was 5 (3-7.5) y, with 62% boys. The median (IQR) time to hospital admission was 7 (4-10) d. Common diagnoses were acute meningoencephalitis, pneumonia, and tropical fever. At admission, the most common immune abnormality was low Natural killer (NK)-cell count (92%), followed by low T-cells (40%) and B-cells (36%). Among immunoglobulins, elevated IgM (27%) was most frequent, while low IgG (17%) and IgA (13%) were seen in a smaller subset. In this cohort, 19 (37%) children died due to severe sepsis. Low IgG was an independent predictor of mortality (OR: 2.77; 95% CI: 1.22-6.28; p = 0.014), irrespective of other immune abnormalities, time to presentation, gender, age at presentation, and illness severity score. At 3-mo follow-up, immune parameters normalized in most survivors, though some showed persistent lymphopenia (mostly low NK-cells), though all were clinically well.

CONCLUSIONS

Low NK-cells, elevated IgM, and low T-/B-cells were common at admission in children with severe sepsis. Low IgG was an independent predictor of mortality. Most immune abnormalities were reversible at 3-mo follow-up.