Soluble L-selectin increases in the cerebrospinal fluid prior to meningeal involvement in children with acute lymphoblastic leukemia.

Soluble L-selectin was determined in the CSF samples of 20 children with CNS leukemia at the time they had blasts in CSF and/or clinical findings of CNS involvement; 17 CSF fluid samples were obtained from 17 of these 20 children, 29-91 days before the appearance of CSF cytological and/or clinical findings of CNS involvement; while 15 CSF samples were withdrawn from among the same group of children, after treatment of meningeal leukemia. In addition, CSF sL-selectin was also assayed in 17 children with ALL, who remained in complete remission at least for a year and, as controls, in 12 children without malignant or meningeal disorders. There was no significant difference in CSF sL-selectin levels between the children with ALL without evidence of meningeal involvement and the controls (1.34 +/- 0.21 ng/ml, 1.46 +/- 0.18 ng/ml respectively, p > 0.05). However, in children with CNS leukemia, not only at the time CNS involvement was diagnosed, but also 29-91 days before the diagnosis of CNS leukemia, the concentrations of the CSF sL-selectin (12.41 +/- 2.14 ng/ml, 7.70 +/- 1.60 ng/ml respectively) were significantly higher than those in controls (p < 0.001 and p < 0.01 respectively). After treatment and disappearance of the blasts in CSF, sL-selectin was found to be decreased and even normalized in the majority of children who had meningeal involvement (2.87 +/- 2.14 ng/ml). In 5 children, the CSF sL-selectin remained high, after the blasts in CSF had disappeared and CNS leukemia recurred within 3 months in 4 of these 5 children. In conclusion, assay of sL-selectin in CSF seems to be a good diagnostic tool in the detection of CNS involvement in children with ALL. This method may also be used as an indicator, in prediction of the CNS leukemia, which is going to develop.