Serum concentrations of apoptosis-associated molecules in septic children with leukemia, neutropenia and fever.

It has been shown that Fas, Fas-L, TNF and TNFR-1 display high serum concentrations in subjects with sepsis. This suggests that these are potential severity markers. However, the serum concentration of these molecules in children with leukemia and suspected sepsis has to be established before proposing their use as diagnostic biomarkers. We included children <17 years of age diagnosed with acute lymphoblastic leukemia with neutropenia and fever (NF). The subjects were divided into two groups: (1) leukemia and NF with sepsis, (2) leukemia and NF without sepsis. Determination of serum levels of TNF-α, TNFR-1, Fas and Fas-L was performed using ELISA tests, and apoptosis percentage using flow cytometry. Seventy-two subjects with ALL and NF were included in the two groups. The highest serum levels of TNF-α (35.2 ± 7.6 pg/ml) and TNF-R1 (4102 ± 2440) and the lowest levels of Fas-L (19.4 ± 7.3 pg/ml) were found in group 2: however, the difference in comparison with patients without sepsis was not statistically significant. Low levels of Fas-L and low percentage of apoptotic cells are observed in septic subjects. This pattern may reflect the presence of sepsis among subjects with NF secondary to leukemia.